/* ==========================================================================
   HSK Vocab — Redesigned UI
   Aesthetic: clean editorial, warm off-white surfaces, ink near-black,
   single accent (vermilion), gold reserved for Hán Việt only.
   ========================================================================== */

:root {
    /* Surfaces */
    --bg: #f7f4ee;
    --surface: #ffffff;
    --surface-2: #f1ece2;
    --surface-3: #e7dfd0;
    --hairline: #e3dccc;
    --hairline-strong: #d4cab5;

    /* Ink */
    --ink: #1a1916;
    --ink-soft: #4a463e;
    --ink-mute: #8a8273;
    --ink-faint: #b6ad99;

    /* Accents */
    --accent: #c0392b;          /* vermilion — primary action / brand */
    --accent-soft: #fbf0ed;
    --accent-tint: rgba(192,57,43,.10);
    --gold: #a37a2c;            /* Hán Việt only */
    --gold-tint: rgba(163,122,44,.08);
    --jade: #5a7d3a;            /* status: mastered */
    --jade-tint: rgba(90,125,58,.10);
    --amber: #b8893d;           /* status: learning */
    --amber-tint: rgba(184,137,61,.10);

    /* Type */
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-serif: 'Fraunces', 'Iowan Old Style', Georgia, serif;
    --font-han: 'Noto Serif SC', 'PingFang SC', 'Songti SC', serif;
    --font-mono: 'JetBrains Mono', ui-monospace, 'SF Mono', monospace;

    /* Radius */
    --r-sm: 8px;
    --r: 12px;
    --r-lg: 16px;
    --r-xl: 22px;
    --r-pill: 999px;

    /* Elevation — flat & subtle */
    --shadow-sm: 0 1px 2px rgba(26,25,22,.04), 0 0 0 1px var(--hairline);
    --shadow: 0 1px 3px rgba(26,25,22,.05), 0 4px 14px -6px rgba(26,25,22,.08);
    --shadow-lg: 0 1px 3px rgba(26,25,22,.06), 0 16px 40px -12px rgba(26,25,22,.16);
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html, body {
    background: var(--bg);
    color: var(--ink);
    font-family: var(--font-sans);
    font-feature-settings: 'cv11', 'ss01';
    min-height: 100vh;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    text-rendering: optimizeLegibility;
}

#app {
    position: relative;
    max-width: 1080px;
    margin: 0 auto;
    padding: 28px 28px 96px;
}

/* ===== HEADER =================================================== */
header {
    display: grid;
    grid-template-columns: 1fr auto auto;
    align-items: center;
    gap: 24px;
    margin-bottom: 22px;
    padding-bottom: 22px;
    border-bottom: 1px solid var(--hairline);
}

.brand {
    display: flex;
    align-items: center;
    gap: 14px;
    min-width: 0;
}

.seal {
    width: 42px;
    height: 42px;
    background: var(--ink);
    color: var(--bg);
    font-family: var(--font-han);
    font-weight: 600;
    font-size: 22px;
    display: grid;
    place-items: center;
    border-radius: 10px;
    flex-shrink: 0;
    letter-spacing: 0;
}

.title-block { min-width: 0; }
.title-block h1 {
    font-family: var(--font-han);
    font-size: 19px;
    font-weight: 600;
    color: var(--ink);
    line-height: 1.1;
    letter-spacing: 0;
}
.title-block .sub {
    font-family: var(--font-sans);
    font-size: 12px;
    font-weight: 500;
    color: var(--ink-mute);
    margin-top: 4px;
    letter-spacing: 0.01em;
}

.header-stats {
    display: flex;
    gap: 0;
    align-items: stretch;
    background: var(--surface);
    border: 1px solid var(--hairline);
    border-radius: var(--r);
    padding: 4px;
}

.stat-pill {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    line-height: 1;
    padding: 8px 14px;
    border-radius: 8px;
    position: relative;
}
.stat-pill + .stat-pill::before {
    content: '';
    position: absolute;
    left: 0;
    top: 18%;
    bottom: 18%;
    width: 1px;
    background: var(--hairline);
}
.stat-pill .num {
    font-family: var(--font-sans);
    font-variant-numeric: tabular-nums;
    font-size: 18px;
    font-weight: 600;
    color: var(--ink);
    letter-spacing: -0.01em;
}
.stat-pill .lbl {
    font-size: 10px;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--ink-mute);
    margin-top: 4px;
    font-weight: 600;
}
.stat-pill.mastered .num { color: var(--jade); }
.stat-pill.learning .num { color: var(--amber); }
.stat-pill.new      .num { color: var(--accent); }

.streak-badge {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px 14px;
    background: var(--surface);
    border: 1px solid var(--hairline);
    border-radius: var(--r-pill);
    font-family: var(--font-sans);
    font-size: 13px;
    font-weight: 600;
    color: var(--ink-soft);
    cursor: default;
    white-space: nowrap;
    line-height: 1;
}
.streak-badge .streak-fire { font-size: 15px; line-height: 1; }
.streak-badge .streak-num {
    font-variant-numeric: tabular-nums;
    font-size: 15px;
    font-weight: 700;
    color: var(--accent);
}

/* ===== TIP BANNER =============================================== */
.tip-banner {
    background: var(--surface);
    border: 1px solid var(--hairline);
    border-radius: var(--r);
    padding: 12px 14px 12px 16px;
    margin-bottom: 16px;
    display: flex;
    gap: 12px;
    align-items: center;
    font-size: 13px;
    color: var(--ink-soft);
    line-height: 1.5;
    position: relative;
}
.tip-banner::before {
    content: '';
    position: absolute;
    left: 0; top: 10px; bottom: 10px;
    width: 3px;
    background: var(--accent);
    border-radius: 0 3px 3px 0;
}
.tip-banner .icon {
    font-family: var(--font-han);
    font-weight: 600;
    color: var(--accent);
    font-size: 18px;
    line-height: 1;
    flex-shrink: 0;
}
.tip-banner b { color: var(--ink); font-weight: 600; }
.tip-banner .close-tip {
    margin-left: auto;
    background: none;
    border: none;
    color: var(--ink-faint);
    cursor: pointer;
    font-size: 22px;
    line-height: 1;
    padding: 4px 6px;
    border-radius: var(--r-sm);
    flex-shrink: 0;
    transition: all .15s ease;
}
.tip-banner .close-tip:hover { color: var(--ink); background: var(--surface-2); }

/* ===== FILTER TOGGLE ============================================ */
.filter-toggle {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: transparent;
    border: 1px solid var(--hairline);
    color: var(--ink-mute);
    padding: 7px 12px;
    border-radius: 10px;
    font-family: var(--font-sans);
    font-size: 12px;
    font-weight: 500;
    cursor: pointer;
    margin-bottom: 10px;
    transition: all .15s ease;
    -webkit-tap-highlight-color: transparent;
}
.filter-toggle:hover { color: var(--ink); border-color: var(--ink-faint); }
.filter-toggle .ft-label { font-weight: 600; letter-spacing: .02em; }
.filter-toggle .ft-summary { color: var(--ink-faint); font-size: 11px; }
.filter-toggle .ft-summary:empty { display: none; }
.filter-toggle .ft-chevron {
    margin-left: auto;
    font-size: 10px;
    transition: transform .2s ease;
    color: var(--ink-faint);
}
.filter-toggle[aria-expanded="false"] .ft-chevron { transform: rotate(-90deg); }
.filter-collapsible.collapsed { display: none; }

/* ===== LEVEL BAR ================================================ */
.level-bar {
    display: flex;
    gap: 2px;
    background: var(--surface);
    padding: 4px;
    border-radius: var(--r);
    border: 1px solid var(--hairline);
    margin-bottom: 10px;
}

.level-btn {
    flex: 1;
    padding: 9px 14px;
    background: transparent;
    border: none;
    border-radius: 8px;
    font-family: var(--font-sans);
    font-size: 13px;
    font-weight: 500;
    color: var(--ink-soft);
    cursor: pointer;
    transition: all .15s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    line-height: 1;
}
.level-btn:hover { color: var(--ink); background: var(--surface-2); }
.level-btn.active {
    background: var(--ink);
    color: var(--bg);
    font-weight: 600;
}
.level-btn .lv-num {
    width: 18px;
    height: 18px;
    border-radius: 50%;
    font-size: 10px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    background: var(--surface-3);
    color: var(--ink-soft);
}
.level-btn.active .lv-num { background: rgba(255,255,255,.15); color: var(--bg); }
.level-btn .lv-count {
    color: var(--ink-faint);
    font-weight: 500;
    font-size: 11px;
    font-variant-numeric: tabular-nums;
}
.level-btn.active .lv-count { color: rgba(255,255,255,.6); }

/* ===== ALPHA RANGE ============================================== */
.alpha-range-bar {
    display: flex;
    align-items: center;
    gap: 10px;
    background: var(--surface);
    padding: 8px 10px;
    border-radius: var(--r);
    border: 1px solid var(--hairline);
    margin-bottom: 18px;
    flex-wrap: wrap;
}
.alpha-range-bar .ar-label {
    font-size: 10px;
    font-weight: 700;
    color: var(--ink-mute);
    letter-spacing: 0.12em;
    text-transform: uppercase;
    white-space: nowrap;
    flex-shrink: 0;
    padding-left: 4px;
}
.alpha-range-bar .ar-letters {
    display: flex;
    gap: 2px;
    flex-wrap: wrap;
    flex: 1;
}
.ar-btn {
    min-width: 26px;
    height: 26px;
    padding: 0 6px;
    background: transparent;
    border: none;
    border-radius: 6px;
    font-family: var(--font-sans);
    font-size: 12px;
    font-weight: 600;
    color: var(--ink-soft);
    cursor: pointer;
    transition: all .12s ease;
    text-transform: uppercase;
    display: flex;
    align-items: center;
    justify-content: center;
    line-height: 1;
}
.ar-btn:hover:not(:disabled) { background: var(--surface-2); color: var(--ink); }
.ar-btn.in-range { background: var(--accent-tint); color: var(--accent); }
.ar-btn.range-start, .ar-btn.range-end {
    background: var(--accent);
    color: #fff;
}
.ar-btn:disabled, .ar-btn.disabled-letter {
    color: var(--ink-faint);
    cursor: not-allowed;
}
.ar-btn.all-btn { font-size: 11px; color: var(--ink-mute); padding: 0 10px; }
.ar-btn.all-btn.active { background: var(--ink); color: var(--bg); }

.ar-divider {
    width: 1px;
    height: 16px;
    background: var(--hairline);
    flex-shrink: 0;
}
.ar-info {
    font-family: var(--font-sans);
    font-size: 12px;
    color: var(--ink-mute);
    white-space: nowrap;
    flex-shrink: 0;
    font-variant-numeric: tabular-nums;
    font-weight: 500;
}
.ar-clear {
    padding: 5px 10px;
    background: transparent;
    border: 1px solid var(--hairline);
    border-radius: 7px;
    font-family: var(--font-sans);
    font-size: 11px;
    font-weight: 600;
    color: var(--ink-mute);
    cursor: pointer;
    transition: all .15s ease;
    white-space: nowrap;
    flex-shrink: 0;
}
.ar-clear:hover:not(:disabled) {
    background: var(--accent);
    border-color: var(--accent);
    color: #fff;
}
.ar-clear:disabled { opacity: .35; cursor: not-allowed; }

/* ===== TOP TABS ================================================= */
nav.tabs {
    display: flex;
    gap: 0;
    margin-bottom: 28px;
    border-bottom: 1px solid var(--hairline);
    padding: 0;
    background: transparent;
    border-radius: 0;
    overflow-x: auto;
    scrollbar-width: none;
}
nav.tabs::-webkit-scrollbar { display: none; }

.tab {
    padding: 11px 18px 13px;
    background: transparent;
    border: none;
    border-radius: 0;
    font-family: var(--font-sans);
    font-size: 13px;
    font-weight: 500;
    color: var(--ink-mute);
    cursor: pointer;
    transition: color .15s ease;
    display: flex;
    align-items: center;
    gap: 8px;
    white-space: nowrap;
    border-bottom: 2px solid transparent;
    margin-bottom: -1px;
    line-height: 1;
}
.tab:hover { color: var(--ink); }
.tab.active {
    color: var(--ink);
    border-bottom-color: var(--ink);
    font-weight: 600;
}
.tab .ch {
    font-family: var(--font-han);
    font-weight: 500;
    font-size: 14px;
    color: var(--ink-faint);
    transition: color .15s ease;
}
.tab.active .ch { color: var(--accent); }

/* ===== VIEWS ==================================================== */
.view { display: none; animation: fadeIn .25s ease; }
.view.active { display: block; }
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(4px); }
    to   { opacity: 1; transform: none; }
}

/* ===== FLASHCARD ================================================ */
.flash-wrap {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 18px;
}

.flash-progress {
    width: 100%;
    max-width: 540px;
    display: flex;
    flex-direction: column;
    gap: 10px;
}
.flash-progress .meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 12px;
    color: var(--ink-mute);
    font-weight: 500;
    font-variant-numeric: tabular-nums;
    letter-spacing: 0.02em;
}
.flash-progress .meta .ch {
    font-family: var(--font-sans);
    color: var(--ink);
    font-weight: 600;
    font-size: 14px;
}
.progress-bar {
    height: 3px;
    background: var(--surface-3);
    border-radius: var(--r-pill);
    overflow: hidden;
}
.progress-bar .fill {
    height: 100%;
    background: var(--ink);
    transition: width .35s cubic-bezier(.4, .2, .2, 1);
}

.card-stage {
    position: relative;
    width: 100%;
    max-width: 540px;
    height: 440px;
    perspective: 1600px;
}

.card {
    position: absolute;
    inset: 0;
    cursor: pointer;
    transform-style: preserve-3d;
    transition: transform .55s cubic-bezier(.4, .2, .2, 1);
}
.card.flipped { transform: rotateY(180deg); }

.face {
    position: absolute;
    inset: 0;
    backface-visibility: hidden;
    -webkit-backface-visibility: hidden;
    background: var(--surface);
    border: 1px solid var(--hairline);
    border-radius: var(--r-xl);
    box-shadow: var(--shadow-lg);
    padding: 32px 28px;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}
.face.back { transform: rotateY(180deg); }

.face-corner {
    position: absolute;
    top: 22px;
    right: 26px;
    font-family: var(--font-sans);
    font-size: 10px;
    font-weight: 600;
    color: var(--ink-faint);
    letter-spacing: 0.1em;
    text-transform: uppercase;
}

.face-status {
    position: absolute;
    top: 22px;
    left: 26px;
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-family: var(--font-sans);
    font-size: 10px;
    color: var(--ink-mute);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    font-weight: 600;
}
.face-status .dot {
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--ink-faint);
}
.status-new      .dot { background: var(--accent); }
.status-learning .dot { background: var(--amber); }
.status-mastered .dot { background: var(--jade); }

.lv-tag {
    position: absolute;
    bottom: 22px;
    left: 50%;
    transform: translateX(-50%);
    font-family: var(--font-sans);
    font-size: 10px;
    color: var(--ink-faint);
    letter-spacing: 0.12em;
    font-weight: 600;
    text-transform: uppercase;
}

.speak-btn {
    position: absolute;
    top: 18px;
    right: 64px;
    width: 36px;
    height: 36px;
    background: transparent;
    border: 1px solid var(--hairline);
    border-radius: 50%;
    cursor: pointer;
    display: grid;
    place-items: center;
    transition: all .18s ease;
    color: var(--ink-soft);
    z-index: 5;
}
.speak-btn:hover {
    background: var(--accent);
    border-color: var(--accent);
    color: #fff;
}
.speak-btn:active { transform: scale(.94); }
.speak-btn svg { width: 16px; height: 16px; }
.speak-btn.speaking {
    background: var(--accent);
    border-color: var(--accent);
    color: #fff;
    animation: pulse 1.1s infinite;
}
@keyframes pulse {
    0%, 100% { box-shadow: 0 0 0 0 rgba(192,57,43,.4); }
    50%      { box-shadow: 0 0 0 8px rgba(192,57,43,0); }
}

.hanzi-big {
    font-family: var(--font-han);
    font-weight: 600;
    color: var(--ink);
    font-size: clamp(80px, 14vw, 128px);
    line-height: 1;
    text-align: center;
    margin: auto 0;
    letter-spacing: -0.02em;
}
.hanzi-big.viet-mode {
    font-family: var(--font-serif);
    font-style: italic;
    font-size: clamp(34px, 7vw, 56px);
    line-height: 1.3;
    max-width: 380px;
    font-weight: 400;
    margin: auto;
}

.tap-hint {
    text-align: center;
    font-family: var(--font-sans);
    font-size: 12px;
    color: var(--ink-faint);
    margin-top: 16px;
    letter-spacing: 0.02em;
}
.tap-hint::before {
    content: '↻ ';
    color: var(--accent);
    font-weight: 500;
}

.back-content {
    display: flex;
    flex-direction: column;
    height: 100%;
    justify-content: center;
    align-items: center;
    text-align: center;
    gap: 12px;
}
.back-hanzi {
    font-family: var(--font-han);
    font-weight: 600;
    font-size: 56px;
    color: var(--ink);
    line-height: 1;
}
.pinyin {
    font-family: var(--font-serif);
    font-style: italic;
    font-size: 22px;
    color: var(--accent);
    font-weight: 500;
    letter-spacing: 0.01em;
}
.han-viet {
    font-family: var(--font-sans);
    font-size: 11px;
    font-weight: 700;
    color: var(--gold);
    letter-spacing: 0.18em;
    background: var(--gold-tint);
    padding: 5px 12px;
    border-radius: 6px;
    text-transform: uppercase;
}
.meaning {
    font-family: var(--font-sans);
    font-size: 17px;
    color: var(--ink);
    font-weight: 500;
    max-width: 380px;
    line-height: 1.4;
    padding: 0 12px;
}

.card-actions {
    display: flex;
    gap: 8px;
    justify-content: center;
    width: 100%;
    max-width: 540px;
    flex-wrap: wrap;
}
.action-btn {
    flex: 1;
    min-width: 100px;
    padding: 12px 14px;
    border: 1px solid var(--hairline);
    border-radius: var(--r);
    font-family: var(--font-sans);
    font-size: 13px;
    font-weight: 600;
    cursor: pointer;
    transition: all .18s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    background: var(--surface);
    color: var(--ink);
    line-height: 1.2;
}
.action-btn:hover { transform: translateY(-1px); box-shadow: var(--shadow); }
.action-btn:active { transform: translateY(0); }

.action-btn.hard {
    border-color: rgba(192,57,43,.3);
    color: var(--accent);
    background: var(--accent-soft);
}
.action-btn.hard:hover { background: var(--accent); border-color: var(--accent); color: #fff; }

.action-btn.ok {
    border-color: rgba(184,137,61,.3);
    color: var(--amber);
    background: var(--amber-tint);
}
.action-btn.ok:hover { background: var(--amber); border-color: var(--amber); color: #fff; }

.action-btn.easy {
    border-color: rgba(90,125,58,.3);
    color: var(--jade);
    background: var(--jade-tint);
}
.action-btn.easy:hover { background: var(--jade); border-color: var(--jade); color: #fff; }

.nav-row {
    display: flex;
    gap: 8px;
    justify-content: center;
    width: 100%;
    max-width: 540px;
    flex-wrap: wrap;
}
.nav-btn {
    padding: 8px 14px;
    background: transparent;
    border: 1px solid var(--hairline);
    border-radius: var(--r-sm);
    font-family: var(--font-sans);
    font-size: 12px;
    font-weight: 500;
    color: var(--ink-soft);
    cursor: pointer;
    transition: all .15s ease;
    display: inline-flex;
    align-items: center;
    gap: 4px;
}
.nav-btn:hover {
    background: var(--surface);
    border-color: var(--hairline-strong);
    color: var(--ink);
}

.flash-toggles {
    display: flex;
    gap: 8px;
    width: 100%;
    max-width: 540px;
    justify-content: center;
    flex-wrap: wrap;
}
.flash-toggle {
    padding: 7px 14px;
    background: transparent;
    border: 1px solid var(--hairline);
    border-radius: var(--r-pill);
    font-family: var(--font-sans);
    font-size: 12px;
    font-weight: 500;
    color: var(--ink-mute);
    cursor: pointer;
    transition: all .15s ease;
    display: inline-flex;
    align-items: center;
    gap: 5px;
}
.flash-toggle:hover { border-color: var(--hairline-strong); color: var(--ink); }
.flash-toggle.active {
    background: var(--ink);
    color: var(--bg);
    border-color: var(--ink);
}

/* ===== BROWSE =================================================== */
.browse-controls {
    display: flex;
    gap: 12px;
    margin-bottom: 14px;
    flex-wrap: wrap;
}
.search-input {
    flex: 1;
    min-width: 240px;
    padding: 12px 16px;
    border: 1px solid var(--hairline);
    border-radius: var(--r);
    background: var(--surface);
    font-family: var(--font-sans);
    font-size: 14px;
    color: var(--ink);
    transition: all .15s ease;
}
.search-input:focus {
    outline: none;
    border-color: var(--ink);
    box-shadow: 0 0 0 3px rgba(26,25,22,.06);
}
.search-input::placeholder { color: var(--ink-faint); }

.filter-pills {
    display: flex;
    gap: 2px;
    background: var(--surface);
    border: 1px solid var(--hairline);
    padding: 4px;
    border-radius: var(--r);
}
.filter-pill {
    padding: 8px 14px;
    background: transparent;
    border: none;
    border-radius: 8px;
    font-family: var(--font-sans);
    font-size: 12px;
    font-weight: 500;
    color: var(--ink-mute);
    cursor: pointer;
    transition: all .15s ease;
    white-space: nowrap;
    line-height: 1;
}
.filter-pill:hover { color: var(--ink); }
.filter-pill.active {
    background: var(--ink);
    color: var(--bg);
    font-weight: 600;
}

.alphabet-bar {
    display: flex;
    gap: 2px;
    margin-bottom: 18px;
    flex-wrap: wrap;
    padding: 6px;
    background: var(--surface);
    border: 1px solid var(--hairline);
    border-radius: var(--r);
}
.alpha-btn {
    width: 30px;
    height: 30px;
    background: transparent;
    border: none;
    border-radius: 7px;
    font-family: var(--font-sans);
    font-size: 12px;
    font-weight: 600;
    color: var(--ink-soft);
    cursor: pointer;
    transition: all .12s ease;
    text-transform: uppercase;
}
.alpha-btn:hover:not(:disabled) { background: var(--surface-2); color: var(--ink); }
.alpha-btn.active { background: var(--ink); color: var(--bg); }
.alpha-btn:disabled { color: var(--ink-faint); cursor: not-allowed; }

.word-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
    gap: 12px;
}
.word-card {
    background: var(--surface);
    border: 1px solid var(--hairline);
    border-radius: var(--r);
    padding: 16px 16px 14px;
    cursor: pointer;
    transition: all .18s ease;
    position: relative;
    overflow: hidden;
}
.word-card::before {
    content: '';
    position: absolute;
    left: 0; top: 12px; bottom: 12px;
    width: 3px;
    background: transparent;
    border-radius: 0 3px 3px 0;
    transition: background .15s ease;
}
.word-card:hover {
    transform: translateY(-2px);
    border-color: var(--hairline-strong);
    box-shadow: var(--shadow);
}
.word-card.s-new::before      { background: var(--accent); }
.word-card.s-learning::before { background: var(--amber); }
.word-card.s-mastered::before { background: var(--jade); }

.word-card .h-row {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: 8px;
    margin-bottom: 6px;
}
.word-card .h {
    font-family: var(--font-han);
    font-weight: 600;
    font-size: 30px;
    color: var(--ink);
    line-height: 1;
    letter-spacing: -0.01em;
}
.word-card .speak-mini {
    width: 28px;
    height: 28px;
    background: transparent;
    border: 1px solid var(--hairline);
    border-radius: 50%;
    cursor: pointer;
    display: grid;
    place-items: center;
    color: var(--ink-soft);
    transition: all .15s ease;
    flex-shrink: 0;
}
.word-card .speak-mini:hover, .word-card .speak-mini.speaking {
    background: var(--accent);
    color: #fff;
    border-color: var(--accent);
}
.word-card .speak-mini svg { width: 13px; height: 13px; }

.word-card .p {
    font-family: var(--font-serif);
    font-style: italic;
    font-size: 14px;
    color: var(--accent);
    margin-bottom: 4px;
    font-weight: 500;
}
.word-card .hv {
    font-family: var(--font-sans);
    font-size: 10px;
    font-weight: 700;
    color: var(--gold);
    letter-spacing: 0.14em;
    margin-bottom: 6px;
    text-transform: uppercase;
}
.word-card .m {
    font-size: 13px;
    color: var(--ink-soft);
    line-height: 1.4;
}
.word-card .meta-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 10px;
    color: var(--ink-mute);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    font-weight: 600;
    margin-top: 12px;
    padding-top: 10px;
    border-top: 1px solid var(--hairline);
}
.word-card .lv-badge {
    background: var(--surface-2);
    padding: 2px 7px;
    border-radius: 4px;
    color: var(--ink-soft);
    font-variant-numeric: tabular-nums;
}

.empty-state {
    text-align: center;
    padding: 64px 20px;
    color: var(--ink-mute);
    grid-column: 1 / -1;
}
.empty-state .ch {
    font-family: var(--font-han);
    font-size: 56px;
    color: var(--ink-faint);
    margin-bottom: 14px;
    font-weight: 500;
}
.empty-state .msg {
    font-family: var(--font-serif);
    font-style: italic;
    font-size: 16px;
}

/* ===== QUIZ ===================================================== */
.quiz-wrap {
    max-width: 600px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 22px;
}

.quiz-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-bottom: 16px;
    border-bottom: 1px solid var(--hairline);
}
.quiz-header .qnum {
    font-family: var(--font-sans);
    font-size: 13px;
    color: var(--ink-mute);
    font-weight: 500;
    font-variant-numeric: tabular-nums;
}
.quiz-header .qnum strong { color: var(--ink); font-weight: 700; }
.quiz-header .qscore {
    font-family: var(--font-sans);
    font-size: 12px;
    color: var(--ink-soft);
    display: flex;
    gap: 14px;
    font-variant-numeric: tabular-nums;
}
.qscore .right { color: var(--jade); font-weight: 700; }
.qscore .wrong { color: var(--accent); font-weight: 700; }

.quiz-card {
    background: var(--surface);
    border: 1px solid var(--hairline);
    border-radius: var(--r-xl);
    padding: 36px 28px 28px;
    box-shadow: var(--shadow);
    text-align: center;
    position: relative;
}

.quiz-question-label {
    font-family: var(--font-sans);
    font-size: 11px;
    text-transform: uppercase;
    letter-spacing: 0.14em;
    color: var(--ink-mute);
    font-weight: 600;
    margin-bottom: 22px;
}

.quiz-question {
    margin-bottom: 28px;
    position: relative;
    min-height: 100px;
}
.quiz-question .qhanzi {
    font-family: var(--font-han);
    font-weight: 600;
    font-size: 80px;
    color: var(--ink);
    line-height: 1;
    letter-spacing: -0.02em;
}
.quiz-question .qpinyin {
    font-family: var(--font-serif);
    font-style: italic;
    font-size: 18px;
    color: var(--accent);
    margin-top: 10px;
    opacity: 0;
    transition: opacity .3s ease;
    font-weight: 500;
}
.quiz-question .qpinyin.show { opacity: 1; }
.quiz-question .qhv-hint {
    font-family: var(--font-sans);
    font-size: 11px;
    font-weight: 700;
    color: var(--gold);
    letter-spacing: 0.18em;
    margin-top: 8px;
    opacity: 0;
    transition: opacity .3s ease;
    text-transform: uppercase;
}
.quiz-question .qhv-hint.show { opacity: 1; }
.quiz-question .qvi {
    font-family: var(--font-serif);
    font-size: 28px;
    color: var(--ink);
    font-weight: 500;
    line-height: 1.3;
}
.quiz-question .speak-btn-q {
    position: absolute;
    top: 0;
    right: 0;
    width: 36px;
    height: 36px;
    background: transparent;
    border: 1px solid var(--hairline);
    border-radius: 50%;
    cursor: pointer;
    display: grid;
    place-items: center;
    color: var(--ink-soft);
    transition: all .18s ease;
}
.quiz-question .speak-btn-q:hover { background: var(--accent); border-color: var(--accent); color: #fff; }
.quiz-question .speak-btn-q svg { width: 16px; height: 16px; }

.quiz-options {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 10px;
}
@media (max-width: 480px) {
    .quiz-options { grid-template-columns: 1fr; }
}
.quiz-option {
    padding: 16px 14px;
    background: var(--surface);
    border: 1px solid var(--hairline);
    border-radius: var(--r);
    font-family: var(--font-sans);
    font-size: 14px;
    color: var(--ink);
    cursor: pointer;
    transition: all .15s ease;
    text-align: center;
    line-height: 1.3;
    font-weight: 500;
}
.quiz-option .opt-h {
    font-family: var(--font-han);
    font-weight: 600;
    font-size: 24px;
    display: block;
    letter-spacing: -0.01em;
}
.quiz-option .opt-p {
    font-family: var(--font-serif);
    font-style: italic;
    color: var(--ink-mute);
    font-size: 12px;
    display: block;
    margin-top: 4px;
}
.quiz-option:hover:not(:disabled) {
    border-color: var(--ink);
    background: var(--bg);
    transform: translateY(-1px);
}
.quiz-option.correct {
    background: var(--jade-tint);
    border-color: var(--jade);
    color: var(--jade);
}
.quiz-option.wrong {
    background: var(--accent-tint);
    border-color: var(--accent);
    color: var(--accent);
}
.quiz-option:disabled { cursor: default; }

.quiz-feedback {
    text-align: center;
    margin-top: 18px;
    min-height: 26px;
    font-family: var(--font-serif);
    font-size: 15px;
    line-height: 1.45;
    font-weight: 400;
}
.quiz-feedback.correct { color: var(--jade); }
.quiz-feedback.wrong   { color: var(--accent); }
.quiz-feedback .hv-tag {
    display: inline-block;
    margin-top: 6px;
    font-family: var(--font-sans);
    font-style: normal;
    font-size: 10px;
    font-weight: 700;
    color: var(--gold);
    letter-spacing: 0.18em;
    background: var(--gold-tint);
    padding: 4px 10px;
    border-radius: 5px;
    text-transform: uppercase;
}

.quiz-next {
    padding: 12px 32px;
    background: var(--ink);
    color: var(--bg);
    border: none;
    border-radius: var(--r);
    font-family: var(--font-sans);
    font-size: 13px;
    font-weight: 600;
    cursor: pointer;
    margin: 18px auto 0;
    display: block;
    transition: all .18s ease;
}
.quiz-next:hover:not(:disabled) { background: #000; transform: translateY(-1px); }
.quiz-next:disabled { opacity: .25; cursor: not-allowed; transform: none; }

/* Listening + pinyin input */
.quiz-listen-big {
    width: 84px;
    height: 84px;
    background: var(--accent);
    border: none;
    border-radius: 50%;
    cursor: pointer;
    display: grid;
    place-items: center;
    margin: 0 auto 12px;
    color: #fff;
    transition: all .18s ease;
    box-shadow: 0 6px 20px -4px rgba(192,57,43,.4);
}
.quiz-listen-big:hover { transform: scale(1.06); }
.quiz-listen-big:active { transform: scale(.95); }
.quiz-listen-big svg { width: 32px; height: 32px; }
.quiz-listen-big.speaking { animation: pulse 1.2s infinite; }

.pinyin-input-wrap {
    display: flex;
    gap: 10px;
    justify-content: center;
    align-items: center;
    flex-wrap: wrap;
}
.pinyin-text-input {
    padding: 13px 18px;
    border: 1px solid var(--hairline);
    border-radius: var(--r);
    background: var(--surface);
    font-family: var(--font-serif);
    font-size: 22px;
    text-align: center;
    color: var(--ink);
    width: 240px;
    transition: all .15s ease;
    font-style: italic;
}
.pinyin-text-input:focus {
    outline: none;
    border-color: var(--ink);
    box-shadow: 0 0 0 3px rgba(26,25,22,.06);
}
.pinyin-text-input.correct { border-color: var(--jade); background: var(--jade-tint); }
.pinyin-text-input.wrong   { border-color: var(--accent); background: var(--accent-tint); }
.pinyin-submit {
    padding: 13px 22px;
    background: var(--ink);
    color: var(--bg);
    border: none;
    border-radius: var(--r);
    font-family: var(--font-sans);
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: all .18s ease;
}
.pinyin-submit:hover { background: #000; transform: translateY(-1px); }

/* ===== MATCH ==================================================== */
.match-wrap { max-width: 720px; margin: 0 auto; }
.match-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 18px;
    padding-bottom: 14px;
    border-bottom: 1px solid var(--hairline);
    flex-wrap: wrap;
    gap: 12px;
}
.match-info {
    font-family: var(--font-sans);
    font-size: 13px;
    color: var(--ink-mute);
    font-variant-numeric: tabular-nums;
}
.match-info strong { color: var(--ink); font-weight: 700; }

.match-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
}
.match-col {
    display: flex;
    flex-direction: column;
    gap: 8px;
}
.match-tile {
    padding: 14px 14px;
    background: var(--surface);
    border: 1px solid var(--hairline);
    border-radius: var(--r);
    cursor: pointer;
    transition: all .15s ease;
    text-align: center;
    user-select: none;
}
.match-tile:hover {
    transform: translateY(-1px);
    border-color: var(--hairline-strong);
    box-shadow: var(--shadow);
}
.match-tile.hanzi {
    font-family: var(--font-han);
    font-weight: 600;
    font-size: 26px;
    color: var(--ink);
    letter-spacing: -0.01em;
}
.match-tile.hanzi .mini-p {
    display: block;
    font-family: var(--font-serif);
    font-style: italic;
    font-size: 11px;
    color: var(--ink-mute);
    margin-top: 4px;
    font-weight: 400;
}
.match-tile.meaning {
    font-family: var(--font-sans);
    font-size: 14px;
    color: var(--ink);
    font-weight: 500;
}
.match-tile.meaning .mini-hv {
    display: block;
    font-size: 9px;
    font-weight: 700;
    color: var(--gold);
    letter-spacing: 0.14em;
    margin-top: 4px;
    text-transform: uppercase;
}
.match-tile.selected {
    border-color: var(--accent);
    background: var(--accent-soft);
    box-shadow: 0 0 0 3px var(--accent-tint);
}
.match-tile.matched {
    background: var(--jade-tint);
    border-color: var(--jade);
    color: var(--jade);
    cursor: default;
    opacity: .55;
    pointer-events: none;
}
.match-tile.matched .mini-p, .match-tile.matched .mini-hv { color: var(--jade); opacity: .8; }
.match-tile.shake { animation: shake .4s ease; border-color: var(--accent); }
@keyframes shake {
    0%, 100% { transform: translateX(0); }
    20%, 60% { transform: translateX(-5px); }
    40%, 80% { transform: translateX(5px); }
}

/* ===== BUTTONS ================================================== */
.btn-primary {
    padding: 11px 22px;
    background: var(--ink);
    color: var(--bg);
    border: none;
    border-radius: var(--r);
    font-family: var(--font-sans);
    font-size: 13px;
    font-weight: 600;
    cursor: pointer;
    transition: all .18s ease;
    display: inline-flex;
    align-items: center;
    gap: 8px;
}
.btn-primary:hover { background: #000; transform: translateY(-1px); }

.btn-secondary {
    padding: 9px 16px;
    background: var(--surface);
    color: var(--ink-soft);
    border: 1px solid var(--hairline);
    border-radius: var(--r-sm);
    font-family: var(--font-sans);
    font-size: 13px;
    font-weight: 500;
    cursor: pointer;
    transition: all .15s ease;
}
.btn-secondary:hover {
    background: var(--surface-2);
    color: var(--ink);
    border-color: var(--hairline-strong);
}

/* ===== STATS ==================================================== */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 12px;
    margin-bottom: 22px;
}
.stat-card {
    background: var(--surface);
    border: 1px solid var(--hairline);
    border-radius: var(--r);
    padding: 22px 22px 20px;
    position: relative;
    overflow: hidden;
}
.stat-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 3px;
    height: 100%;
}
.stat-card.s-total::before    { background: var(--ink); }
.stat-card.s-mastered::before { background: var(--jade); }
.stat-card.s-learning::before { background: var(--amber); }
.stat-card.s-new::before      { background: var(--accent); }

.stat-card .label {
    font-family: var(--font-sans);
    font-size: 10px;
    text-transform: uppercase;
    letter-spacing: 0.12em;
    color: var(--ink-mute);
    font-weight: 700;
    margin-bottom: 14px;
}
.stat-card .value {
    font-family: var(--font-sans);
    font-variant-numeric: tabular-nums;
    font-size: 40px;
    font-weight: 600;
    color: var(--ink);
    line-height: 1;
    letter-spacing: -0.02em;
}
.stat-card .pct {
    font-family: var(--font-sans);
    font-size: 12px;
    color: var(--ink-mute);
    margin-top: 10px;
    font-weight: 500;
}

.progress-section {
    background: var(--surface);
    border: 1px solid var(--hairline);
    border-radius: var(--r);
    padding: 24px;
    margin-bottom: 14px;
}
.progress-section h3 {
    font-family: var(--font-sans);
    font-size: 15px;
    font-weight: 600;
    color: var(--ink);
    margin-bottom: 18px;
    letter-spacing: -0.01em;
}

.level-progress-block { margin-bottom: 18px; }
.level-progress-block:last-child { margin-bottom: 0; }
.lpb-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 12px;
    color: var(--ink-mute);
    margin-bottom: 8px;
    font-variant-numeric: tabular-nums;
}
.lpb-header .lpb-lbl { font-weight: 600; color: var(--ink); font-size: 13px; }

.big-progress {
    height: 14px;
    background: var(--surface-2);
    border-radius: var(--r-pill);
    overflow: hidden;
    display: flex;
    border: 1px solid var(--hairline);
}
.big-progress .seg {
    height: 100%;
    transition: width .6s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-size: 9px;
    font-weight: 700;
    overflow: hidden;
    letter-spacing: 0.05em;
}
.big-progress .seg.mastered { background: var(--jade); }
.big-progress .seg.learning { background: var(--amber); }
.big-progress .seg.new      { background: var(--surface-3); color: var(--ink-mute); }

.legend {
    display: flex;
    gap: 18px;
    margin-top: 16px;
    flex-wrap: wrap;
    font-size: 12px;
    color: var(--ink-soft);
    font-weight: 500;
}
.legend-item { display: flex; align-items: center; gap: 6px; }
.legend-item .sw { width: 10px; height: 10px; border-radius: 3px; }
.legend-item.mastered .sw { background: var(--jade); }
.legend-item.learning .sw { background: var(--amber); }
.legend-item.new      .sw { background: var(--surface-3); border: 1px solid var(--hairline); }

.reset-section { display: flex; gap: 12px; flex-wrap: wrap; }
.danger-btn {
    padding: 10px 18px;
    background: transparent;
    border: 1px solid var(--accent);
    color: var(--accent);
    border-radius: var(--r-sm);
    font-family: var(--font-sans);
    font-size: 13px;
    font-weight: 500;
    cursor: pointer;
    transition: all .15s ease;
}
.danger-btn:hover { background: var(--accent); color: #fff; }

/* ===== TOAST ==================================================== */
.toast {
    position: fixed;
    bottom: 28px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--ink);
    color: var(--bg);
    padding: 12px 20px;
    border-radius: var(--r);
    font-family: var(--font-sans);
    font-size: 13px;
    font-weight: 500;
    box-shadow: var(--shadow-lg);
    z-index: 100;
    opacity: 0;
    visibility: hidden;
    transition: opacity .2s ease, visibility .2s;
    max-width: 90vw;
    pointer-events: none;
}
.toast.show { opacity: 1; visibility: visible; }

/* ===== DONE CARD ================================================ */
.done-card { text-align: center; padding: 40px 24px; }
.done-card .seal-big {
    width: 72px;
    height: 72px;
    background: var(--jade);
    color: #fff;
    font-family: var(--font-han);
    font-weight: 600;
    font-size: 36px;
    display: grid;
    place-items: center;
    border-radius: 14px;
    margin: 0 auto 22px;
}
.done-card h2 {
    font-family: var(--font-sans);
    font-size: 22px;
    font-weight: 600;
    color: var(--ink);
    margin-bottom: 8px;
    letter-spacing: -0.01em;
}
.done-card p {
    font-family: var(--font-serif);
    font-style: italic;
    color: var(--ink-mute);
    margin-bottom: 22px;
    font-size: 15px;
}

/* ===== RADICAL BREAKDOWN ======================================== */
.radical-box {
    margin-top: 16px;
    padding: 14px 16px;
    background: var(--gold-tint);
    border: 1px solid rgba(163,122,44,.2);
    border-radius: var(--r);
    text-align: left;
    width: 100%;
    max-width: 380px;
}
.radical-title {
    font-family: var(--font-sans);
    font-size: 10px;
    text-transform: uppercase;
    letter-spacing: 0.14em;
    color: var(--gold);
    font-weight: 700;
    margin-bottom: 10px;
    display: flex;
    align-items: center;
    gap: 6px;
}
.radical-parts {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
    margin-bottom: 10px;
    align-items: center;
}
.radical-part {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 2px;
    background: var(--surface);
    padding: 8px 12px;
    border-radius: var(--r-sm);
    border: 1px solid var(--hairline);
    min-width: 50px;
}
.radical-part .rp-char {
    font-family: var(--font-han);
    font-size: 24px;
    font-weight: 600;
    color: var(--ink);
    line-height: 1;
}
.radical-part .rp-mean {
    font-size: 10px;
    color: var(--ink-mute);
    font-weight: 500;
}
.radical-plus {
    font-family: var(--font-serif);
    font-size: 16px;
    color: var(--ink-faint);
    display: flex;
    align-items: center;
}
.radical-story {
    font-family: var(--font-serif);
    font-style: italic;
    font-size: 13px;
    color: var(--ink-soft);
    line-height: 1.5;
    padding: 8px 10px;
    background: var(--surface);
    border-radius: var(--r-sm);
    border-left: 2px solid var(--gold);
}

/* ===== WRITING ================================================== */
.write-wrap {
    max-width: 600px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 22px;
}
.write-char-display {
    display: flex;
    align-items: center;
    gap: 28px;
    flex-wrap: wrap;
    justify-content: center;
}
.write-info { text-align: center; }
.write-info .wi-hanzi {
    font-family: var(--font-han);
    font-size: 44px;
    font-weight: 600;
    color: var(--ink);
    line-height: 1;
}
.write-info .wi-pinyin {
    font-family: var(--font-serif);
    font-style: italic;
    font-size: 17px;
    color: var(--accent);
    margin-top: 6px;
    font-weight: 500;
}
.write-info .wi-meaning {
    font-size: 13px;
    color: var(--ink-soft);
    margin-top: 4px;
}

.writer-container {
    width: 260px;
    height: 260px;
    background: var(--surface);
    border-radius: var(--r-lg);
    box-shadow: var(--shadow);
    border: 1px solid var(--hairline);
    position: relative;
    overflow: hidden;
    background-image:
        linear-gradient(var(--hairline), var(--hairline)),
        linear-gradient(90deg, var(--hairline), var(--hairline));
    background-size: 1px 100%, 100% 1px;
    background-position: center, center;
    background-repeat: no-repeat;
}
.writer-container svg { display: block; position: relative; z-index: 1; }

.write-controls { display: flex; gap: 10px; flex-wrap: wrap; justify-content: center; }
.write-btn {
    padding: 10px 18px;
    border: 1px solid var(--hairline);
    border-radius: var(--r-sm);
    background: var(--surface);
    font-family: var(--font-sans);
    font-size: 13px;
    font-weight: 500;
    color: var(--ink-soft);
    cursor: pointer;
    transition: all .15s ease;
    display: inline-flex;
    align-items: center;
    gap: 6px;
}
.write-btn:hover {
    background: var(--surface-2);
    color: var(--ink);
    border-color: var(--hairline-strong);
}
.write-btn.active {
    background: var(--ink);
    color: var(--bg);
    border-color: var(--ink);
}

.write-nav { display: flex; gap: 10px; align-items: center; }
.write-nav .wn-label {
    font-family: var(--font-sans);
    font-size: 12px;
    color: var(--ink-mute);
    font-variant-numeric: tabular-nums;
    font-weight: 500;
}

.write-mode-pills {
    display: flex;
    gap: 2px;
    background: var(--surface);
    border: 1px solid var(--hairline);
    padding: 4px;
    border-radius: var(--r);
}
.write-mode-pill {
    padding: 9px 18px;
    background: transparent;
    border: none;
    border-radius: 8px;
    font-family: var(--font-sans);
    font-size: 13px;
    font-weight: 500;
    color: var(--ink-mute);
    cursor: pointer;
    transition: all .15s ease;
    line-height: 1;
}
.write-mode-pill:hover { color: var(--ink); }
.write-mode-pill.active {
    background: var(--ink);
    color: var(--bg);
    font-weight: 600;
}

.write-result {
    font-family: var(--font-serif);
    font-style: italic;
    font-size: 15px;
    color: var(--ink-mute);
    min-height: 24px;
    text-align: center;
}
.write-result.success { color: var(--jade); }
.write-result.fail    { color: var(--accent); }

/* ===== SIMILAR ================================================== */
.similar-wrap { max-width: 720px; margin: 0 auto; }
.similar-grid { display: flex; flex-direction: column; gap: 14px; }
.similar-card {
    background: var(--surface);
    border: 1px solid var(--hairline);
    border-radius: var(--r);
    padding: 22px 22px 20px;
    transition: all .2s ease;
}
.similar-card:hover { box-shadow: var(--shadow); }
.similar-card .sc-label {
    font-family: var(--font-sans);
    font-size: 10px;
    text-transform: uppercase;
    letter-spacing: 0.14em;
    color: var(--ink-mute);
    font-weight: 700;
    margin-bottom: 14px;
}
.similar-pair {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
    margin-bottom: 14px;
}
.similar-char {
    flex: 1;
    min-width: 130px;
    background: var(--bg);
    padding: 16px 14px;
    border-radius: var(--r);
    text-align: center;
    cursor: pointer;
    transition: all .18s ease;
    border: 1px solid var(--hairline);
}
.similar-char:hover {
    border-color: var(--accent);
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}
.similar-char .sc-h {
    font-family: var(--font-han);
    font-size: 42px;
    font-weight: 600;
    color: var(--ink);
    line-height: 1;
    letter-spacing: -0.02em;
}
.similar-char .sc-p {
    font-family: var(--font-serif);
    font-style: italic;
    font-size: 14px;
    color: var(--accent);
    margin-top: 8px;
    font-weight: 500;
}
.similar-char .sc-hv {
    font-family: var(--font-sans);
    font-size: 9px;
    font-weight: 700;
    color: var(--gold);
    letter-spacing: 0.14em;
    text-transform: uppercase;
    margin-top: 4px;
}
.similar-char .sc-v {
    font-size: 12px;
    color: var(--ink-soft);
    margin-top: 6px;
}
.similar-tip {
    font-family: var(--font-serif);
    font-style: italic;
    font-size: 13px;
    color: var(--ink-soft);
    line-height: 1.5;
    padding: 12px 14px;
    background: var(--bg);
    border-radius: var(--r-sm);
    border-left: 2px solid var(--accent);
}
.similar-tip b { color: var(--ink); font-weight: 600; }

/* ===== SWIPE HINT (mobile only) ================================ */
.swipe-hint {
    display: none;
    justify-content: center;
    gap: 18px;
    font-size: 11px;
    color: var(--ink-mute);
    font-family: var(--font-sans);
    width: 100%;
    max-width: 540px;
    padding: 0 4px;
    margin-top: 4px;
    font-weight: 500;
}
.swipe-hint span { display: flex; align-items: center; gap: 4px; }
.swipe-hint .sh-icon { font-size: 13px; }

/* ===== BOTTOM NAV (mobile only) ================================ */
.bottom-nav { display: none; }

/* ===== RESPONSIVE =============================================== */
@media (max-width: 880px) {
    header { gap: 12px; }
    .header-stats .stat-pill { padding: 6px 10px; }
    .header-stats .stat-pill .num { font-size: 16px; }
}

@media (max-width: 700px) {
    #app { padding: 16px 14px 100px; }

    /* Header */
    header {
        grid-template-columns: 1fr auto;
        grid-template-areas:
            "brand streak"
            "stats stats";
        gap: 12px;
        margin-bottom: 16px;
        padding-bottom: 16px;
    }
    .brand { grid-area: brand; }
    .streak-badge { grid-area: streak; padding: 6px 10px; font-size: 12px; }
    .streak-badge .streak-num { font-size: 14px; }
    .header-stats { grid-area: stats; justify-self: stretch; justify-content: space-between; }
    .header-stats .stat-pill { padding: 8px 10px; flex: 1; }
    .header-stats .stat-pill .num { font-size: 18px; }

    .title-block h1 { font-size: 17px; }
    .title-block .sub { font-size: 11px; }
    .seal { width: 38px; height: 38px; font-size: 19px; }

    /* Hide top tabs — bottom nav takes over */
    nav.tabs { display: none; }

    /* Level bar — keep horizontal */
    .level-bar {
        overflow-x: auto;
        scrollbar-width: none;
        flex-wrap: nowrap;
    }
    .level-bar::-webkit-scrollbar { display: none; }
    .level-btn { flex-shrink: 0; padding: 8px 12px; font-size: 12px; white-space: nowrap; }

    /* Cards / quiz */
    .card-stage { height: 380px; }
    .face { padding: 28px 20px; }
    .hanzi-big { font-size: clamp(72px, 16vw, 100px); }
    .face-corner { right: 22px; top: 20px; }
    .face-status { left: 22px; top: 20px; }
    .speak-btn { right: 60px; top: 16px; }
    .lv-tag { bottom: 18px; }

    /* Quiz */
    .quiz-wrap { gap: 16px; }
    .quiz-card { padding: 26px 18px 22px; border-radius: var(--r-lg); }
    .quiz-question .qhanzi { font-size: clamp(56px, 14vw, 80px); }
    .quiz-question .qvi { font-size: 22px; }
    .quiz-options { grid-template-columns: 1fr 1fr; gap: 8px; }
    .quiz-option { padding: 13px 10px; font-size: 13px; }
    .quiz-option .opt-h { font-size: 22px; }
    .quiz-next { padding: 12px 24px; width: 100%; }

    /* Match */
    .match-grid { gap: 8px; }
    .match-tile { padding: 11px 10px; }
    .match-tile.hanzi { font-size: 22px; }
    .match-tile.meaning { font-size: 12px; line-height: 1.3; }

    /* Browse */
    .browse-controls { gap: 8px; }
    .search-input { font-size: 14px; padding: 11px 14px; }
    .filter-pill { padding: 7px 11px; font-size: 11px; }
    .alphabet-bar { padding: 5px; gap: 2px; margin-bottom: 14px; }
    .alpha-btn { width: 28px; height: 28px; font-size: 11px; }
    .word-grid { grid-template-columns: 1fr 1fr; gap: 10px; }
    .word-card { padding: 14px 12px 12px; }
    .word-card .h { font-size: 26px; }
    .word-card .p { font-size: 12px; }
    .word-card .hv { font-size: 9px; }
    .word-card .m { font-size: 12px; }

    /* Stats */
    .stats-grid { grid-template-columns: 1fr 1fr; gap: 10px; }
    .stat-card { padding: 16px 16px 14px; }
    .stat-card .value { font-size: 32px; }
    .progress-section { padding: 18px; }

    /* Toast above bottom nav + card actions */
    .toast { bottom: calc(140px + env(safe-area-inset-bottom)); }

    /* Bottom nav */
    .bottom-nav {
        display: flex;
        position: fixed;
        bottom: 0;
        left: 0;
        right: 0;
        background: var(--surface);
        border-top: 1px solid var(--hairline);
        padding: 0;
        z-index: 50;
        box-shadow: 0 -2px 14px -4px rgba(26,25,22,.08);
        padding-bottom: env(safe-area-inset-bottom);
    }
    .bn-tab {
        flex: 1;
        display: flex;
        flex-direction: column;
        align-items: center;
        justify-content: center;
        padding: 9px 2px 7px;
        background: transparent;
        border: none;
        cursor: pointer;
        transition: all .12s ease;
        gap: 3px;
        -webkit-tap-highlight-color: transparent;
        min-height: 54px;
        min-width: 0;
        position: relative;
    }
    .bn-tab .bn-icon {
        font-family: var(--font-han);
        font-size: 17px;
        color: var(--ink-faint);
        transition: color .12s ease;
        line-height: 1;
        font-weight: 500;
    }
    .bn-tab .bn-lbl {
        font-family: var(--font-sans);
        font-size: 10px;
        font-weight: 500;
        color: var(--ink-mute);
        letter-spacing: 0;
        transition: color .12s ease;
        white-space: nowrap;
        overflow: hidden;
        text-overflow: ellipsis;
        max-width: 100%;
    }
    .bn-tab.active .bn-icon { color: var(--accent); }
    .bn-tab.active .bn-lbl  { color: var(--ink); font-weight: 600; }
    .bn-tab.active::before {
        content: '';
        position: absolute;
        top: 0;
        left: 50%;
        transform: translateX(-50%);
        width: 24px;
        height: 2px;
        background: var(--accent);
        border-radius: 0 0 2px 2px;
    }
    .bn-tab:active { background: var(--surface-2); }

    /* Show swipe hint on mobile */
    .swipe-hint { display: flex; }

    /* Misc */
    .writer-container { width: 220px; height: 220px; }
    .write-info .wi-hanzi { font-size: 36px; }
    .similar-char .sc-h { font-size: 34px; }
    .similar-pair { gap: 8px; }
    .similar-card { padding: 16px 16px 14px; }
    .radical-part .rp-char { font-size: 22px; }
    .radical-part { padding: 6px 10px; min-width: 44px; }
    .write-char-display { gap: 16px; }
}

@media (max-width: 420px) {
    .word-grid { grid-template-columns: 1fr; }
    .header-stats { padding: 3px; }
    .header-stats .stat-pill { padding: 6px 8px; }
    .header-stats .stat-pill .lbl { font-size: 9px; }
}


/* ==========================================================================
   THEME: INK GARDEN — bold, dark, sophisticated CJK editorial
   ========================================================================== */
[data-theme="ink"] {
    --bg: #0e1411;
    --surface: #131c18;
    --surface-2: #1a2520;
    --surface-3: #243029;
    --hairline: #243029;
    --hairline-strong: #34433a;
    --ink: #f0e8d4;
    --ink-soft: #c4bca8;
    --ink-mute: #8a8675;
    --ink-faint: #5a5b50;
    --accent: #e8b339;
    --accent-soft: rgba(232,179,57,.08);
    --accent-tint: rgba(232,179,57,.16);
    --gold: #d4a847;
    --gold-tint: rgba(212,168,71,.10);
    --jade: #8eb87a;
    --jade-tint: rgba(142,184,122,.14);
    --amber: #d99858;
    --amber-tint: rgba(217,152,88,.12);
    --font-sans: 'Plus Jakarta Sans', 'Inter', -apple-system, sans-serif;
    --font-serif: 'Instrument Serif', 'Fraunces', Georgia, serif;
    --shadow-sm: 0 1px 2px rgba(0,0,0,.4), 0 0 0 1px var(--hairline);
    --shadow: 0 4px 14px rgba(0,0,0,.4), 0 0 0 1px var(--hairline);
    --shadow-lg: 0 24px 48px rgba(0,0,0,.5), 0 0 0 1px var(--hairline);
}
[data-theme="ink"] body { background: var(--bg); }
[data-theme="ink"] .seal {
    background: var(--accent);
    color: #0e1411;
    border-radius: 4px;
}
[data-theme="ink"] .title-block h1 { letter-spacing: 0.01em; }
[data-theme="ink"] .level-btn.active,
[data-theme="ink"] .filter-pill.active,
[data-theme="ink"] .write-mode-pill.active,
[data-theme="ink"] .alpha-btn.active,
[data-theme="ink"] .ar-btn.all-btn.active {
    background: var(--accent);
    color: #0e1411;
}
[data-theme="ink"] .level-btn .lv-num { background: var(--surface-3); color: var(--ink-soft); }
[data-theme="ink"] .level-btn.active .lv-num { background: rgba(0,0,0,.2); color: #0e1411; }
[data-theme="ink"] .level-btn.active .lv-count { color: rgba(14,20,17,.55); }
[data-theme="ink"] nav.tabs { border-bottom-color: var(--hairline); }
[data-theme="ink"] .tab.active { color: var(--accent); border-bottom-color: var(--accent); }
[data-theme="ink"] .tab.active .ch { color: var(--accent); }
[data-theme="ink"] .progress-bar .fill { background: var(--accent); }
[data-theme="ink"] .face { background: var(--surface); }
[data-theme="ink"] .hanzi-big { color: var(--accent); font-weight: 500; }
[data-theme="ink"] .back-hanzi { color: var(--accent); font-weight: 500; }
[data-theme="ink"] .pinyin { color: var(--ink); font-style: italic; font-family: var(--font-serif); font-size: 26px; }
[data-theme="ink"] .meaning { color: var(--ink-soft); }
[data-theme="ink"] .quiz-question .qhanzi { color: var(--accent); font-weight: 500; }
[data-theme="ink"] .quiz-question .qpinyin { color: var(--ink); font-family: var(--font-serif); }
[data-theme="ink"] .quiz-question .qvi { font-family: var(--font-serif); }
[data-theme="ink"] .quiz-listen-big { background: var(--accent); color: #0e1411; box-shadow: 0 8px 24px -6px rgba(232,179,57,.5); }
[data-theme="ink"] .quiz-next, [data-theme="ink"] .pinyin-submit, [data-theme="ink"] .btn-primary {
    background: var(--accent); color: #0e1411;
}
[data-theme="ink"] .quiz-next:hover, [data-theme="ink"] .pinyin-submit:hover, [data-theme="ink"] .btn-primary:hover {
    background: #f4c659; color: #0e1411;
}
[data-theme="ink"] .word-card .h, [data-theme="ink"] .match-tile.hanzi, [data-theme="ink"] .similar-char .sc-h {
    color: var(--accent); font-weight: 500;
}
[data-theme="ink"] .word-card .p, [data-theme="ink"] .similar-char .sc-p { color: var(--ink); font-family: var(--font-serif); }
[data-theme="ink"] .speak-btn:hover, [data-theme="ink"] .speak-btn.speaking,
[data-theme="ink"] .word-card .speak-mini:hover, [data-theme="ink"] .word-card .speak-mini.speaking {
    background: var(--accent); border-color: var(--accent); color: #0e1411;
}
[data-theme="ink"] .stat-pill.new .num,
[data-theme="ink"] .word-card.s-new::before,
[data-theme="ink"] .stat-card.s-new::before { color: var(--accent); background: var(--accent); }
[data-theme="ink"] .bn-tab.active .bn-icon { color: var(--accent); }
[data-theme="ink"] .bn-tab.active::before { background: var(--accent); }
[data-theme="ink"] .tip-banner::before { background: var(--accent); }
[data-theme="ink"] .tip-banner .icon { color: var(--accent); }
[data-theme="ink"] .danger-btn { color: #e87878; border-color: #e87878; }
[data-theme="ink"] .danger-btn:hover { background: #e87878; color: var(--bg); }
[data-theme="ink"] .toast { background: var(--accent); color: #0e1411; }
[data-theme="ink"] .streak-badge .streak-num { color: var(--accent); }
[data-theme="ink"] .han-viet { color: var(--gold); background: var(--gold-tint); }

/* ==========================================================================
   THEME: SOFT — modern Linear/Notion-inspired, cool grey, glass surfaces
   ========================================================================== */
[data-theme="soft"] {
    --bg: #f4f4f6;
    --surface: #ffffff;
    --surface-2: #ececef;
    --surface-3: #dfdfe4;
    --hairline: #e7e7eb;
    --hairline-strong: #d1d1d8;
    --ink: #18181b;
    --ink-soft: #44444a;
    --ink-mute: #71717a;
    --ink-faint: #a1a1aa;
    --accent: #6366f1;
    --accent-soft: #eef0ff;
    --accent-tint: rgba(99,102,241,.10);
    --gold: #b45309;
    --gold-tint: rgba(180,83,9,.08);
    --jade: #16a34a;
    --jade-tint: rgba(22,163,74,.10);
    --amber: #d97706;
    --amber-tint: rgba(217,119,6,.10);
    --font-sans: 'Inter', -apple-system, sans-serif;
    --font-serif: 'Fraunces', Georgia, serif;
    --r-sm: 6px;
    --r: 10px;
    --r-lg: 14px;
    --r-xl: 18px;
    --shadow-sm: 0 1px 2px rgba(24,24,27,.04), 0 0 0 1px var(--hairline);
    --shadow: 0 1px 3px rgba(24,24,27,.06), 0 8px 24px -10px rgba(24,24,27,.10);
    --shadow-lg: 0 1px 3px rgba(24,24,27,.08), 0 24px 48px -16px rgba(24,24,27,.18);
}
[data-theme="soft"] body { background: var(--bg); }
[data-theme="soft"] .seal { background: var(--accent); color: #fff; border-radius: 8px; }
[data-theme="soft"] .level-btn.active,
[data-theme="soft"] .filter-pill.active,
[data-theme="soft"] .write-mode-pill.active,
[data-theme="soft"] .alpha-btn.active,
[data-theme="soft"] .ar-btn.all-btn.active {
    background: var(--accent); color: #fff;
}
[data-theme="soft"] .level-btn.active .lv-num { background: rgba(255,255,255,.2); color: #fff; }
[data-theme="soft"] .ar-btn.range-start, [data-theme="soft"] .ar-btn.range-end { background: var(--accent); }
[data-theme="soft"] .ar-clear:hover:not(:disabled) { background: var(--accent); border-color: var(--accent); }
[data-theme="soft"] .tab.active { color: var(--accent); border-bottom-color: var(--accent); }
[data-theme="soft"] .tab.active .ch { color: var(--accent); }
[data-theme="soft"] .progress-bar .fill { background: var(--accent); }
[data-theme="soft"] .pinyin { color: var(--accent); }
[data-theme="soft"] .quiz-question .qpinyin { color: var(--accent); }
[data-theme="soft"] .word-card .p, [data-theme="soft"] .similar-char .sc-p { color: var(--accent); }
[data-theme="soft"] .quiz-listen-big { background: var(--accent); box-shadow: 0 8px 24px -6px rgba(99,102,241,.4); }
[data-theme="soft"] .quiz-next, [data-theme="soft"] .pinyin-submit, [data-theme="soft"] .btn-primary { background: var(--accent); }
[data-theme="soft"] .quiz-next:hover, [data-theme="soft"] .pinyin-submit:hover, [data-theme="soft"] .btn-primary:hover { background: #4f52d6; }
[data-theme="soft"] .speak-btn:hover, [data-theme="soft"] .speak-btn.speaking,
[data-theme="soft"] .word-card .speak-mini:hover, [data-theme="soft"] .word-card .speak-mini.speaking,
[data-theme="soft"] .quiz-question .speak-btn-q:hover {
    background: var(--accent); border-color: var(--accent); color: #fff;
}
[data-theme="soft"] .stat-pill.new .num { color: var(--accent); }
[data-theme="soft"] .word-card.s-new::before { background: var(--accent); }
[data-theme="soft"] .stat-card.s-new::before { background: var(--accent); }
[data-theme="soft"] .bn-tab.active .bn-icon { color: var(--accent); }
[data-theme="soft"] .bn-tab.active::before { background: var(--accent); }
[data-theme="soft"] .tip-banner::before { background: var(--accent); }
[data-theme="soft"] .tip-banner .icon { color: var(--accent); }
[data-theme="soft"] .streak-badge .streak-num { color: var(--accent); }
[data-theme="soft"] .face { background: var(--surface); }
[data-theme="soft"] .hanzi-big, [data-theme="soft"] .back-hanzi,
[data-theme="soft"] .word-card .h, [data-theme="soft"] .match-tile.hanzi,
[data-theme="soft"] .similar-char .sc-h, [data-theme="soft"] .quiz-question .qhanzi {
    color: var(--ink); font-weight: 500;
}
[data-theme="soft"] .quiz-option.correct,
[data-theme="soft"] .action-btn.easy:hover,
[data-theme="soft"] .match-tile.matched { background: var(--jade-tint); border-color: var(--jade); color: var(--jade); }
[data-theme="soft"] .action-btn.hard {
    border-color: rgba(220,38,38,.25); color: #dc2626; background: rgba(220,38,38,.05);
}
[data-theme="soft"] .action-btn.hard:hover { background: #dc2626; border-color: #dc2626; color: #fff; }
[data-theme="soft"] .toast { background: var(--ink); color: var(--bg); }

/* ==========================================================================
   TWEAKS PANEL placement — bottom-left, off bottom-nav on mobile
   ========================================================================== */
@media (max-width: 700px) {
    .tweaks-panel-wrap { bottom: 78px !important; }
}


/* Dark theme — writer grid + small fixes */
[data-theme="ink"] .writer-container {
    background: var(--surface);
    background-image:
        linear-gradient(var(--hairline-strong), var(--hairline-strong)),
        linear-gradient(90deg, var(--hairline-strong), var(--hairline-strong));
    background-size: 1px 100%, 100% 1px;
    background-position: center, center;
    background-repeat: no-repeat;
}
[data-theme="ink"] .writer-container svg path[fill] { fill: var(--accent) !important; }
[data-theme="ink"] .write-info .wi-hanzi { color: var(--accent); font-weight: 500; }
[data-theme="ink"] .write-info .wi-pinyin { color: var(--ink); font-family: var(--font-serif); }

/* Soft theme — slightly tighter, refined controls */
[data-theme="soft"] header { border-bottom-color: var(--hairline); }
[data-theme="soft"] .face { box-shadow: 0 1px 3px rgba(24,24,27,.06), 0 24px 48px -16px rgba(99,102,241,.12); }
[data-theme="soft"] .write-info .wi-pinyin { color: var(--accent); }

/* Ink theme — quiz card subtle glow */
[data-theme="ink"] .quiz-card,
[data-theme="ink"] .stat-card,
[data-theme="ink"] .progress-section,
[data-theme="ink"] .similar-card,
[data-theme="ink"] .word-card,
[data-theme="ink"] .match-tile,
[data-theme="ink"] .face {
    background: var(--surface);
}
[data-theme="ink"] .alphabet-bar, [data-theme="ink"] .level-bar,
[data-theme="ink"] .header-stats, [data-theme="ink"] .filter-pills,
[data-theme="ink"] .write-mode-pills, [data-theme="ink"] .alpha-range-bar,
[data-theme="ink"] .tip-banner, [data-theme="ink"] .streak-badge,
[data-theme="ink"] .search-input {
    background: var(--surface);
    border-color: var(--hairline);
}
[data-theme="ink"] .search-input { color: var(--ink); }
[data-theme="ink"] .search-input::placeholder { color: var(--ink-faint); }
[data-theme="ink"] .search-input:focus { border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); }
[data-theme="ink"] .progress-bar { background: var(--surface-3); }
[data-theme="ink"] .big-progress { background: var(--surface-2); border-color: var(--hairline); }
[data-theme="ink"] .big-progress .seg.new { background: var(--surface-3); color: var(--ink-mute); }
[data-theme="ink"] .lpb-header .lpb-lbl, [data-theme="ink"] .progress-section h3 { color: var(--ink); }
[data-theme="ink"] .stat-card .value { color: var(--ink); }
[data-theme="ink"] .stat-card.s-total::before { background: var(--ink); }
[data-theme="ink"] .similar-char { background: var(--surface-2); border-color: var(--hairline); }
[data-theme="ink"] .similar-char:hover { border-color: var(--accent); }
[data-theme="ink"] .similar-tip { background: var(--surface-2); border-left-color: var(--accent); color: var(--ink-soft); }
[data-theme="ink"] .similar-tip b { color: var(--ink); }
[data-theme="ink"] .radical-box { background: var(--accent-soft); border-color: rgba(232,179,57,.2); }
[data-theme="ink"] .radical-part { background: var(--surface-2); border-color: var(--hairline); }
[data-theme="ink"] .radical-part .rp-char { color: var(--ink); }
[data-theme="ink"] .radical-story { background: var(--surface-2); border-left-color: var(--accent); }

/* Ink theme — tap hint and small text refinements */
[data-theme="ink"] .tap-hint { color: var(--ink-mute); }
[data-theme="ink"] .face-corner, [data-theme="ink"] .lv-tag { color: var(--ink-faint); }
[data-theme="ink"] .word-card .meta-row { border-top-color: var(--hairline); }
[data-theme="ink"] .word-card .lv-badge { background: var(--surface-3); color: var(--ink-soft); }
[data-theme="ink"] .quiz-question .qpinyin { font-size: 22px; }
[data-theme="ink"] .quiz-feedback.correct { color: #a8d690; }
[data-theme="ink"] .nav-btn, [data-theme="ink"] .flash-toggle, [data-theme="ink"] .write-btn {
    background: transparent;
    color: var(--ink-soft);
    border-color: var(--hairline);
}
[data-theme="ink"] .nav-btn:hover, [data-theme="ink"] .flash-toggle:hover, [data-theme="ink"] .write-btn:hover {
    background: var(--surface-2);
    color: var(--ink);
    border-color: var(--hairline-strong);
}
[data-theme="ink"] .flash-toggle.active, [data-theme="ink"] .write-btn.active {
    background: var(--accent);
    color: #0e1411;
    border-color: var(--accent);
}
[data-theme="ink"] .quiz-option {
    background: var(--surface-2);
    border-color: var(--hairline);
    color: var(--ink);
}
[data-theme="ink"] .quiz-option:hover:not(:disabled) {
    border-color: var(--accent);
    background: var(--surface);
}
[data-theme="ink"] .quiz-option .opt-h { color: var(--accent); font-weight: 500; }
[data-theme="ink"] .quiz-option.correct {
    background: var(--jade-tint); border-color: var(--jade); color: var(--jade);
}
[data-theme="ink"] .quiz-option.correct .opt-h { color: var(--jade); }
[data-theme="ink"] .quiz-option.wrong {
    background: rgba(232,89,89,.14); border-color: #e85959; color: #e85959;
}
[data-theme="ink"] .quiz-option.wrong .opt-h { color: #e85959; }
[data-theme="ink"] .pinyin-text-input {
    background: var(--surface-2); color: var(--ink); border-color: var(--hairline);
}
[data-theme="ink"] .pinyin-text-input:focus { border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); }
[data-theme="ink"] .action-btn {
    background: var(--surface-2);
    border-color: var(--hairline);
    color: var(--ink);
}
[data-theme="ink"] .action-btn.hard {
    background: rgba(232,89,89,.10); border-color: rgba(232,89,89,.3); color: #e85959;
}
[data-theme="ink"] .action-btn.hard:hover { background: #e85959; border-color: #e85959; color: #0e1411; }
[data-theme="ink"] .action-btn.ok {
    background: var(--amber-tint); border-color: rgba(217,152,88,.3); color: var(--amber);
}
[data-theme="ink"] .action-btn.ok:hover { background: var(--amber); border-color: var(--amber); color: #0e1411; }
[data-theme="ink"] .action-btn.easy {
    background: var(--jade-tint); border-color: rgba(142,184,122,.3); color: var(--jade);
}
[data-theme="ink"] .action-btn.easy:hover { background: var(--jade); border-color: var(--jade); color: #0e1411; }
[data-theme="ink"] .alpha-btn:disabled { color: var(--ink-faint); }
[data-theme="ink"] .alpha-btn:hover:not(:disabled) { background: var(--surface-3); color: var(--ink); }
[data-theme="ink"] .ar-btn:hover:not(:disabled) { background: var(--surface-3); color: var(--ink); }
[data-theme="ink"] .ar-btn.in-range { background: var(--accent-tint); color: var(--accent); }
[data-theme="ink"] .filter-pill:hover { color: var(--ink); }
[data-theme="ink"] .level-btn:hover { background: var(--surface-2); color: var(--ink); }
[data-theme="ink"] .write-mode-pill:hover { color: var(--ink); }
[data-theme="ink"] .bottom-nav { background: var(--surface); border-top-color: var(--hairline); box-shadow: 0 -4px 20px rgba(0,0,0,.4); }
[data-theme="ink"] .bn-tab .bn-icon { color: var(--ink-mute); }
[data-theme="ink"] .bn-tab .bn-lbl { color: var(--ink-mute); }
[data-theme="ink"] .bn-tab.active .bn-lbl { color: var(--ink); }
[data-theme="ink"] .bn-tab:active { background: var(--surface-2); }

/* Ink theme — tweaks panel readability */
[data-theme="ink"] .tweaks-panel-wrap > div {
    background: rgba(20,28,24,.96) !important;
    border-color: rgba(255,255,255,.08) !important;
    color: var(--ink) !important;
    box-shadow: 0 24px 48px -12px rgba(0,0,0,.6), 0 0 0 1px rgba(255,255,255,.04) !important;
}

/* Subtle mode-tag at top so users know which theme is active (only visible in non-default) */
.theme-tag {
    display: none;
    position: fixed;
    top: 12px;
    left: 50%;
    transform: translateX(-50%);
    font-family: 'Inter', sans-serif;
    font-size: 10px;
    font-weight: 600;
    letter-spacing: 0.14em;
    text-transform: uppercase;
    background: var(--surface);
    color: var(--ink-mute);
    border: 1px solid var(--hairline);
    padding: 5px 12px;
    border-radius: 999px;
    z-index: 30;
    pointer-events: none;
    opacity: 0;
    transition: opacity .3s ease;
}
.theme-tag.show { opacity: 1; }


/* ==========================================================================
   POLISH LAYER — UX refinements (Nov 2026)
   ========================================================================== */

/* Tighter, more elegant header */
header {
    grid-template-columns: auto 1fr auto;
    gap: 18px;
    margin-bottom: 18px;
    padding-bottom: 18px;
}
.brand { gap: 12px; }
.seal {
    width: 38px;
    height: 38px;
    font-size: 19px;
    border-radius: 9px;
}
.title-block h1 { font-size: 17px; letter-spacing: 0.005em; }
.title-block .sub { font-size: 11px; margin-top: 3px; opacity: .85; }

/* Inline stat pills — flat, smaller, single-row */
.header-stats {
    border: none;
    background: transparent;
    padding: 0;
    gap: 18px;
    border-radius: 0;
    justify-self: end;
}
.stat-pill {
    flex-direction: row;
    align-items: baseline;
    gap: 6px;
    padding: 0;
    border-radius: 0;
}
.stat-pill + .stat-pill::before { display: none; }
.stat-pill .num {
    font-size: 16px;
    font-weight: 600;
    letter-spacing: -0.01em;
}
.stat-pill .lbl {
    font-size: 10px;
    margin-top: 0;
    text-transform: none;
    letter-spacing: 0.01em;
    color: var(--ink-mute);
    font-weight: 500;
}

/* Streak — chip, not pill, sits cleaner */
.streak-badge {
    padding: 6px 11px;
    font-size: 12px;
    background: transparent;
    border-color: var(--hairline);
    gap: 6px;
}
.streak-badge .streak-fire { font-size: 13px; }
.streak-badge .streak-num { font-size: 13px; }

/* Tip banner — slimmer, more refined */
.tip-banner {
    padding: 10px 14px 10px 16px;
    font-size: 12.5px;
    margin-bottom: 14px;
    border-radius: 10px;
}
.tip-banner::before { width: 2px; top: 8px; bottom: 8px; }
.tip-banner .icon { font-size: 15px; }
.tip-banner .close-tip { font-size: 18px; padding: 2px 6px; }

/* Level bar — softer, more pill-like, less black dominance */
.level-bar {
    background: transparent;
    border: none;
    padding: 0;
    gap: 8px;
    margin-bottom: 8px;
}
.level-btn {
    background: var(--surface);
    border: 1px solid var(--hairline);
    padding: 9px 14px 10px;
    border-radius: 10px;
    font-size: 12.5px;
    transition: all .18s ease;
}
.level-btn:hover {
    background: var(--surface);
    border-color: var(--hairline-strong);
    transform: translateY(-1px);
    box-shadow: 0 2px 8px -2px rgba(26,25,22,.06);
}
.level-btn.active {
    background: var(--ink);
    color: var(--bg);
    border-color: var(--ink);
}
.level-btn.active:hover { transform: translateY(-1px); }
.level-btn .lv-num {
    width: 16px;
    height: 16px;
    font-size: 9px;
    border-radius: 4px;
}
[data-theme="ink"] .level-btn { background: var(--surface); border-color: var(--hairline); }
[data-theme="soft"] .level-btn { background: var(--surface); }

/* Pinyin range — compress when on desktop, less repetitive feel */
.alpha-range-bar {
    padding: 6px 10px 6px 12px;
    border-radius: 10px;
    margin-bottom: 16px;
    background: var(--surface);
}
.ar-btn { min-width: 24px; height: 24px; font-size: 11px; border-radius: 5px; }
.alpha-range-bar .ar-label { font-size: 9px; }
.ar-info { font-size: 11px; }
.ar-clear { padding: 4px 9px; font-size: 10px; border-radius: 6px; }

/* Top tabs — refined active indicator with smooth animation */
nav.tabs {
    margin-bottom: 24px;
    gap: 4px;
    padding-bottom: 0;
    position: relative;
}
.tab {
    padding: 12px 16px 14px;
    font-size: 12.5px;
    border-radius: 8px 8px 0 0;
    border-bottom: 2px solid transparent;
    transition: color .15s ease, background .15s ease, border-color .25s ease;
}
.tab:hover { background: var(--surface-2); color: var(--ink); }
.tab.active {
    background: transparent;
    color: var(--ink);
    border-bottom-color: var(--accent);
}
.tab.active .ch { color: var(--accent); transform: scale(1.05); }
.tab .ch { transition: transform .15s ease, color .15s ease; font-size: 13px; }
[data-theme="ink"] .tab:hover { background: var(--surface-2); }

/* Card stage — subtle stack illusion (peek behind on hover) */
.card-stage { isolation: isolate; }
.card-stage::before, .card-stage::after {
    content: '';
    position: absolute;
    left: 6%;
    right: 6%;
    bottom: -6px;
    height: 24px;
    background: var(--surface);
    border: 1px solid var(--hairline);
    border-top: none;
    border-radius: 0 0 var(--r-xl) var(--r-xl);
    pointer-events: none;
    transition: transform .35s cubic-bezier(.4,.2,.2,1), opacity .35s ease;
    z-index: -1;
    opacity: .55;
}
.card-stage::after {
    left: 11%;
    right: 11%;
    bottom: -12px;
    opacity: .3;
}
.card-stage:hover::before { transform: translateY(2px); opacity: .8; }
.card-stage:hover::after  { transform: translateY(2px); opacity: .5; }

/* Card itself — slightly more refined */
.face {
    border-radius: var(--r-xl);
    padding: 36px 32px;
}
.face-status, .face-corner { font-size: 9.5px; }
.lv-tag { font-size: 9.5px; bottom: 24px; }

/* Speak button — cleaner, more subtle */
.speak-btn {
    top: 20px;
    right: 60px;
    width: 32px;
    height: 32px;
}
.speak-btn svg { width: 14px; height: 14px; }

/* Hanzi — slightly larger, optical center */
.hanzi-big { font-size: clamp(96px, 16vw, 144px); margin-top: -8px; }

/* Tap hint — subtler */
.tap-hint {
    font-size: 11px;
    margin-top: 12px;
    color: var(--ink-faint);
    letter-spacing: 0.04em;
}
.tap-hint::before { display: none; }

/* Action buttons — calmer borders, sharper hover */
.action-btn {
    padding: 13px 14px;
    font-size: 12.5px;
    border-radius: 10px;
    transition: transform .12s ease, box-shadow .15s ease, background .15s ease, border-color .15s ease, color .15s ease;
}
.action-btn:hover { transform: translateY(-2px); box-shadow: 0 6px 14px -6px rgba(26,25,22,.16); }

/* Word cards — more interactive feel */
.word-card {
    transition: transform .18s ease, border-color .15s ease, box-shadow .2s ease;
    border-radius: 10px;
}
.word-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 24px -10px rgba(26,25,22,.16);
}
.word-card .h { font-size: 28px; }
.word-card .meta-row { padding-top: 9px; margin-top: 10px; }

/* Search input — cleaner */
.search-input {
    padding: 11px 16px;
    font-size: 13.5px;
    border-radius: 10px;
}

/* Filter pills — flatter */
.filter-pills, .write-mode-pills {
    border-radius: 10px;
    padding: 3px;
}
.filter-pill { padding: 7px 13px; font-size: 11.5px; border-radius: 7px; }

/* Quiz card — softer shadow */
.quiz-card {
    padding: 36px 30px 28px;
    border-radius: 18px;
    box-shadow: 0 1px 3px rgba(26,25,22,.04), 0 12px 32px -16px rgba(26,25,22,.10);
}
.quiz-question .qhanzi { font-size: clamp(64px, 12vw, 88px); }
.quiz-option { padding: 14px 14px; border-radius: 10px; }

/* Match tiles — softer */
.match-tile { padding: 14px 14px; border-radius: 10px; transition: all .15s ease; }
.match-tile.hanzi { font-size: 24px; }
.match-tile.selected {
    border-color: var(--accent);
    background: var(--accent-soft);
    box-shadow: 0 0 0 3px var(--accent-tint), 0 4px 12px -4px rgba(192,57,43,.2);
    transform: translateY(-1px);
}

/* Stat cards — refined */
.stat-card { padding: 20px 22px 18px; border-radius: 12px; }
.stat-card .label { font-size: 9.5px; margin-bottom: 12px; }
.stat-card .value { font-size: 36px; }

/* Progress section */
.progress-section { padding: 22px 22px 20px; border-radius: 12px; }

/* Bottom nav (mobile) — slightly more refined */
@media (max-width: 700px) {
    .bottom-nav {
        background: rgba(255,255,255,.92);
        backdrop-filter: blur(14px);
        -webkit-backdrop-filter: blur(14px);
    }
    [data-theme="ink"] .bottom-nav { background: rgba(20,28,24,.92); }
    [data-theme="soft"] .bottom-nav { background: rgba(255,255,255,.92); }
    .bn-tab { padding: 10px 2px 8px; min-height: 56px; }
    .bn-tab .bn-icon { font-size: 18px; transition: transform .2s cubic-bezier(.4,.2,.2,1); }
    .bn-tab.active .bn-icon { transform: scale(1.1) translateY(-1px); }
    .bn-tab .bn-lbl { font-size: 9.5px; }

    /* Mobile header - even tighter */
    header { gap: 10px; padding-bottom: 14px; margin-bottom: 14px; }
    .header-stats { gap: 12px; justify-content: flex-start; }
    .stat-pill .num { font-size: 14px; }
    .stat-pill .lbl { font-size: 10px; }
    .seal { width: 34px; height: 34px; font-size: 17px; }
    .title-block h1 { font-size: 16px; }
    .title-block .sub { font-size: 10.5px; }
    .level-bar { gap: 6px; }
    .level-btn { padding: 8px 11px; font-size: 11.5px; }
}

/* Keyboard shortcut hints — small kbd badges next to action buttons */
.kbd {
    display: inline-block;
    font-family: var(--font-mono);
    font-size: 9.5px;
    font-weight: 600;
    padding: 1px 5px;
    border: 1px solid var(--hairline-strong);
    border-bottom-width: 2px;
    border-radius: 4px;
    background: var(--surface);
    color: var(--ink-mute);
    line-height: 1.4;
    margin-left: 6px;
    vertical-align: 1px;
    letter-spacing: 0;
}
.action-btn .kbd { background: rgba(255,255,255,.5); }
.action-btn.hard .kbd, .action-btn.ok .kbd, .action-btn.easy .kbd {
    background: rgba(255,255,255,.65);
    border-color: rgba(0,0,0,.1);
}
.action-btn:hover .kbd { background: rgba(255,255,255,.85); color: var(--ink); }
[data-theme="ink"] .kbd { background: var(--surface-2); color: var(--ink-soft); border-color: var(--hairline-strong); }
[data-theme="ink"] .action-btn .kbd { background: rgba(0,0,0,.2); color: var(--ink); }
@media (max-width: 700px) { .kbd { display: none; } }

/* Smoother animations */
* {
    -webkit-tap-highlight-color: transparent;
}
.face, .quiz-card, .word-card, .match-tile, .stat-card,
.action-btn, .quiz-option, .level-btn, .filter-pill {
    will-change: auto;
}

/* Reduced-motion respect */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: .01ms !important;
        transition-duration: .01ms !important;
    }
}

/* Subtle scroll-fade on word grid edges */
.word-grid { padding-bottom: 4px; }

/* Quiz feedback — better positioning */
.quiz-feedback { font-size: 14px; padding: 0 8px; }

/* Polished focus rings */
button:focus-visible, input:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
}
button:focus:not(:focus-visible) { outline: none; }