:root {
    --ink-bg: #26343c;
    --ink-bg-deep: #1b262c;
    --paper: #f1ead6;
    --grid-line: rgba(38, 32, 20, 0.07);
    --ink-line: rgba(38, 32, 20, 0.18);
    --ink-line-strong: rgba(38, 32, 20, 0.35);
    --ink-text: #262019;
    --ink-muted: #6b6255;
    --mist: #8fa3a8;
    --shu: #c1440e;
    --shu-dark: #9c360b;
    --shu-soft-bg: rgba(193, 68, 14, 0.08);
    --voice-ok: #2f6b4f;
    --font-jp: 'BIZ UDPMincho', 'Noto Serif JP', serif;
    --font-vn: 'Be Vietnam Pro', 'Segoe UI', sans-serif;
    --shadow-offset: 6px 6px 0 rgba(15, 20, 23, 0.35);
    --shadow-offset-sm: 4px 4px 0 rgba(15, 20, 23, 0.35);
}

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

body {
    font-family: var(--font-vn);
    background: radial-gradient(circle at 50% -10%, #33434c 0%, #212d34 55%, var(--ink-bg-deep) 100%);
    min-height: 100vh;
    padding: 20px;
}

.container {
    max-width: 760px;
    margin: 0 auto;
}

/* Link back to the tuanpham.site landing page (same in every app) */
.site-home {
    display: inline-block;
    margin-bottom: 8px;
    font-family: var(--font-vn);
    font-size: 0.8rem;
    color: var(--mist);
    text-decoration: none;
}

.site-home:hover {
    color: var(--paper);
}

/* Header */
.app-header {
    text-align: center;
    margin-bottom: 26px;
}

.app-mark {
    font-family: var(--font-jp);
    font-size: 1.9rem;
    font-weight: 700;
    color: var(--paper);
    letter-spacing: 0.05em;
}

.app-tagline {
    font-family: var(--font-vn);
    font-size: 0.85rem;
    color: var(--mist);
    letter-spacing: 0.03em;
    margin-top: 2px;
}

h2 {
    font-family: var(--font-vn);
    color: var(--ink-text);
    font-weight: 700;
    margin-bottom: 16px;
    font-size: 1.25rem;
}

h3 {
    font-family: var(--font-vn);
    color: var(--ink-muted);
    font-weight: 600;
    margin-bottom: 10px;
    font-size: 0.9rem;
    letter-spacing: 0.02em;
}

/* Sections */
section {
    background: var(--paper);
    border: 1px solid var(--ink-line);
    border-radius: 4px;
    padding: 24px;
    margin-bottom: 20px;
    box-shadow: var(--shadow-offset);
}

/* Config Section */
.config-section {
    max-height: 80vh;
    overflow-y: auto;
}

.config-group {
    margin-bottom: 25px;
    padding-bottom: 20px;
    border-bottom: 1px solid var(--ink-line);
}

.config-group:last-of-type {
    border-bottom: none;
}

/* Options Section */
.options-group {
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
    margin-bottom: 15px;
}

.options-group label {
    display: flex;
    align-items: center;
    gap: 8px;
    cursor: pointer;
    font-size: 0.95rem;
    color: var(--ink-text);
}

.options-group select {
    padding: 6px 10px;
    border-radius: 3px;
    border: 1px solid var(--ink-line);
    font-size: 0.95rem;
    font-family: var(--font-vn);
    background: var(--paper);
    color: var(--ink-text);
}

/* Selection Controls */
.selection-controls {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-bottom: 20px;
}

.selection-controls button {
    padding: 8px 16px;
    border: 1px solid var(--ink-line);
    border-radius: 3px;
    background: transparent;
    color: var(--ink-text);
    cursor: pointer;
    font-family: var(--font-vn);
    font-size: 0.85rem;
    font-weight: 600;
    transition: border-color 0.2s, color 0.2s;
}

.selection-controls button:hover {
    border-color: var(--shu);
    color: var(--shu);
}

/* Script Tabs (Hiragana/Katakana/Vocabulary) */
.script-tabs {
    display: flex;
    gap: 4px;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
    margin-bottom: 20px;
    border-bottom: 1px solid var(--ink-line);
}

.script-tab,
.learn-tab {
    flex: 0 0 auto;
    white-space: nowrap;
    padding: 10px 18px;
    border: none;
    border-bottom: 3px solid transparent;
    background: transparent;
    color: var(--ink-muted);
    cursor: pointer;
    font-family: var(--font-vn);
    font-size: 0.95rem;
    font-weight: 600;
    transition: color 0.2s, border-color 0.2s;
}

.script-tab:hover,
.learn-tab:hover {
    color: var(--ink-text);
}

.script-tab.active,
.learn-tab.active {
    color: var(--shu);
    border-bottom-color: var(--shu);
}

.script-section {
    display: none;
}

.script-section.active {
    display: block;
}

/* Vocabulary List */
.vocabulary-list {
    display: flex;
    flex-direction: column;
}

.vocabulary-item {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 14px;
    padding: 12px 14px 12px 16px;
    border-bottom: 1px solid var(--ink-line);
    border-left: 3px solid transparent;
    cursor: pointer;
    transition: background 0.15s, border-left-color 0.15s;
}

.vocabulary-item:hover {
    border-left-color: var(--ink-line-strong);
    background: rgba(38, 32, 20, 0.04);
}

.vocabulary-item.selected {
    border-left-color: var(--shu);
    background: var(--shu-soft-bg);
}

.vocab-vietnamese {
    font-family: var(--font-vn);
    font-size: 1rem;
    font-weight: 600;
    color: var(--ink-text);
    flex: 1 1 45%;
}

.vocab-japanese {
    font-family: var(--font-jp);
    font-size: 1.15rem;
    font-weight: 700;
    color: var(--ink-text);
}

.vocab-romaji {
    font-family: var(--font-vn);
    font-size: 0.8rem;
    color: var(--ink-muted);
}

/* Row Controls */
.row-controls {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 8px;
    margin-bottom: 15px;
}

.row-controls span {
    font-family: var(--font-vn);
    font-size: 0.85rem;
    color: var(--ink-muted);
    min-width: 80px;
}

.row-btn {
    width: 36px;
    height: 36px;
    border: 1px solid var(--ink-line);
    border-radius: 3px;
    background: var(--paper);
    color: var(--ink-text);
    cursor: pointer;
    font-family: var(--font-jp);
    font-size: 1.05rem;
    font-weight: 700;
    transition: background 0.15s, color 0.15s, border-color 0.15s;
}

.row-btn:hover {
    border-color: var(--ink-line-strong);
}

.row-btn.active {
    background: var(--ink-text);
    color: var(--paper);
    border-color: var(--ink-text);
}

.lesson-btn {
    width: auto;
    height: auto;
    padding: 8px 16px;
    font-family: var(--font-vn);
    font-size: 0.85rem;
}

/* Character Groups */
.character-groups {
    display: flex;
    flex-direction: column;
    gap: 14px;
}

.character-group {
    border: 1px solid var(--ink-line);
    border-radius: 3px;
    padding: 14px;
}

.character-group h3 {
    font-size: 0.85rem;
    margin-bottom: 10px;
}

.character-group h4 {
    font-family: var(--font-vn);
    font-size: 0.8rem;
    color: var(--ink-muted);
    margin: 14px 0 4px;
}

.character-list {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.character-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 8px;
    border: 1px solid var(--ink-line);
    border-radius: 3px;
    cursor: pointer;
    transition: background 0.15s, color 0.15s, border-color 0.15s;
    min-width: 58px;
    background: var(--paper);
}

.character-item:hover {
    border-color: var(--ink-line-strong);
}

.character-item.selected {
    background: var(--ink-text);
    border-color: var(--ink-text);
}

.character-item .char {
    font-family: var(--font-jp);
    font-size: 1.4rem;
    font-weight: 700;
    color: var(--ink-text);
}

.character-item .romaji {
    font-family: var(--font-vn);
    font-size: 0.7rem;
    color: var(--ink-muted);
}

.character-item.selected .char,
.character-item.selected .romaji {
    color: var(--paper);
}

/* Floating Save/Cancel buttons */
.config-actions-float {
    position: fixed;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 10px;
    z-index: 100;
    background: var(--paper);
    border: 1px solid var(--ink-line);
    padding: 10px 14px;
    border-radius: 4px;
    box-shadow: var(--shadow-offset-sm);
}

.save-btn {
    padding: 12px 28px;
    font-family: var(--font-vn);
    font-size: 1rem;
    font-weight: 700;
    border: none;
    border-radius: 3px;
    background: var(--shu);
    color: var(--paper);
    cursor: pointer;
    transition: background 0.2s;
}

.save-btn:hover {
    background: var(--shu-dark);
}

.cancel-btn {
    padding: 12px 22px;
    font-family: var(--font-vn);
    font-size: 1rem;
    font-weight: 600;
    border: 1px solid var(--ink-line);
    border-radius: 3px;
    background: transparent;
    color: var(--ink-text);
    cursor: pointer;
    transition: border-color 0.2s;
}

.cancel-btn:hover {
    border-color: var(--ink-text);
}

#selectedCount {
    margin-top: 10px;
    margin-bottom: 80px; /* Space for floating buttons */
    color: var(--ink-muted);
    font-size: 0.85rem;
}

/* Flashcard Section */
.flashcard-section {
    text-align: center;
}

.progress {
    font-family: var(--font-vn);
    font-weight: 600;
    font-size: 0.95rem;
    color: var(--ink-muted);
    margin-bottom: 18px;
    letter-spacing: 0.02em;
}

.progress #currentIndex {
    color: var(--shu);
    font-weight: 700;
}

/* Flashcard */
.flashcard {
    width: 320px;
    height: 380px;
    margin: 0 auto 28px;
    -webkit-perspective: 1000px;
    perspective: 1000px;
    cursor: grab;
    user-select: none;
    -webkit-user-select: none;
    touch-action: pan-y;
}

.flashcard-inner {
    position: relative;
    width: 100%;
    height: 100%;
    transition: transform 0.6s;
    -webkit-transform-style: preserve-3d;
    transform-style: preserve-3d;
    -webkit-backface-visibility: hidden;
    backface-visibility: hidden;
}

.flashcard.flipped .flashcard-inner {
    -webkit-transform: rotateY(180deg);
    transform: rotateY(180deg);
}

/* These stay bare (no box-shadow/overflow) so backface-visibility actually
   hides them on iOS/WebKit - combining it with a shadow or clipped overflow
   on the same element is a long-standing WebKit bug that shows both faces
   mid-flip. All visual styling lives on the nested .flashcard-face instead. */
.flashcard-front,
.flashcard-back {
    position: absolute;
    width: 100%;
    height: 100%;
    -webkit-backface-visibility: hidden;
    backface-visibility: hidden;
}

.flashcard-front {
    -webkit-transform: translateZ(0);
    transform: translateZ(0);
}

.flashcard-back {
    -webkit-transform: rotateY(180deg) translateZ(0);
    transform: rotateY(180deg) translateZ(0);
}

.flashcard-face {
    position: relative;
    width: 100%;
    height: 100%;
    border-radius: 4px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: 32px 28px;
    text-align: center;
    border: 1px solid var(--ink-line);
    box-shadow: var(--shadow-offset);
    background-color: var(--paper);
    background-image:
        linear-gradient(var(--grid-line) 1px, transparent 1px),
        linear-gradient(90deg, var(--grid-line) 1px, transparent 1px);
    background-size: 26px 26px;
    overflow: hidden;
    color: var(--ink-text);
}

.flashcard-face::before {
    content: '';
    position: absolute;
    top: 0;
    bottom: 0;
    left: 26px;
    width: 2px;
    background: var(--shu);
    opacity: 0.5;
}

.flashcard-front .main-content {
    font-family: var(--font-jp);
    font-size: 6rem;
    font-weight: 700;
    color: var(--ink-text);
    word-break: break-word;
    line-height: 1.2;
    position: relative;
    z-index: 1;
}

.flashcard-front .main-content.romaji-front {
    font-family: var(--font-vn);
    font-size: 1.6rem;
    font-weight: 500;
}

.flashcard-front .main-content.speak-front {
    font-size: 4rem;
    cursor: pointer;
}

.main-content.jp-oneline,
.flashcard-back .character.jp-oneline {
    white-space: nowrap;
    word-break: normal;
}

/* Too long for one line even at the minimum size: wrap instead */
.main-content.jp-wrap,
.flashcard-back .character.jp-wrap {
    white-space: normal;
    overflow-wrap: anywhere;
}

.flashcard-back .character {
    font-family: var(--font-jp);
    font-size: 4.5rem;
    font-weight: 700;
    margin-bottom: 12px;
    position: relative;
    z-index: 1;
}

.flashcard-back .romaji {
    font-family: var(--font-vn);
    font-size: 1.3rem;
    color: var(--ink-muted);
    word-break: break-word;
    position: relative;
    z-index: 1;
}

/* Controls */
.controls {
    display: flex;
    justify-content: center;
    gap: 12px;
    margin-bottom: 16px;
}

.controls button {
    padding: 11px 22px;
    font-family: var(--font-vn);
    font-size: 0.9rem;
    font-weight: 600;
    border: 1px solid var(--ink-line);
    border-radius: 3px;
    background: var(--paper);
    color: var(--ink-text);
    cursor: pointer;
    transition: background 0.2s, color 0.2s, border-color 0.2s;
}

.controls button:hover {
    border-color: var(--ink-line-strong);
}

#toggleAuto {
    background: var(--shu);
    border-color: var(--shu);
    color: var(--paper);
}

#toggleAuto:hover {
    background: var(--shu-dark);
    border-color: var(--shu-dark);
}

#toggleAuto.running {
    background: var(--ink-text);
    border-color: var(--ink-text);
    color: var(--paper);
}

/* Auto Progress */
.auto-progress {
    margin-top: 20px;
    text-align: center;
}

.timer-bar {
    width: 100%;
    max-width: 280px;
    height: 4px;
    background: rgba(38, 32, 20, 0.12);
    border-radius: 2px;
    margin: 0 auto 10px;
    overflow: hidden;
}

.timer-fill {
    height: 100%;
    background: var(--shu);
    border-radius: 2px;
    width: 0%;
    transition: width 0.1s linear;
}

#autoStatus {
    font-family: var(--font-vn);
    color: var(--ink-muted);
    font-size: 0.85rem;
}

/* Voice Status */
.voice-status {
    margin-top: 15px;
    text-align: center;
    font-family: var(--font-vn);
    font-size: 0.8rem;
    color: var(--ink-muted);
}

.voice-status.has-voice {
    color: var(--voice-ok);
}

.voice-status.no-voice {
    color: var(--shu);
}

/* Responsive */
@media (max-width: 600px) {
    .app-mark {
        font-size: 1.5rem;
    }

    .flashcard {
        width: 260px;
        height: 320px;
    }

    .flashcard-front .main-content {
        font-size: 4.5rem;
    }

    .flashcard-back .character {
        font-size: 3.2rem;
    }

    .controls {
        flex-wrap: wrap;
    }

    .controls button {
        padding: 10px 18px;
        font-size: 0.85rem;
    }
}

/* Learn Section */
.learn-section {
    padding-bottom: 20px;
}

.learn-header {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 10px;
    margin-bottom: 16px;
}

.learn-header h2 {
    margin-right: auto;
}

.learn-header button {
    padding: 8px 16px;
    font-family: var(--font-vn);
    font-size: 0.85rem;
    font-weight: 600;
    border: 1px solid var(--ink-line);
    border-radius: 3px;
    background: var(--paper);
    color: var(--ink-text);
    cursor: pointer;
}

.learn-header button:hover {
    border-color: var(--ink-line-strong);
}

.learn-list {
    list-style: none;
}

.learn-item {
    /* Grid, not flex: each column keeps its own width, so long Japanese text
       wraps inside its column instead of running into the speaker button. */
    display: grid;
    grid-template-columns: minmax(0, 38%) minmax(0, 1fr) auto;
    align-items: center;
    column-gap: 16px;
    row-gap: 4px;
    padding: 12px 4px;
    border-bottom: 1px solid var(--ink-line);
}

.learn-kana {
    min-width: 0;
    font-family: var(--font-jp);
    font-size: 1.6rem;
    line-height: 1.3;
    overflow-wrap: anywhere;
}

.learn-text {
    display: flex;
    flex-direction: column;
    gap: 2px;
    min-width: 0;
}

.learn-romaji {
    color: var(--shu);
    font-weight: 600;
}

.learn-meaning {
    color: var(--ink-muted);
    font-size: 0.9rem;
}

.learn-speak {
    border: 1px solid var(--ink-line);
    border-radius: 3px;
    background: var(--paper);
    padding: 6px 10px;
    cursor: pointer;
}

.learn-speak:hover {
    border-color: var(--ink-line-strong);
}

.learn-group {
    margin-bottom: 24px;
}

.learn-group h3 {
    margin-bottom: 4px;
}

.learn-section .row-controls {
    margin-bottom: 16px;
}

/* Grammar cards */
.grammar-card {
    margin-bottom: 18px;
    padding: 14px 16px;
    border: 1px solid var(--ink-line);
    border-radius: 4px;
    background: var(--shu-soft-bg);
}

.grammar-card h4 {
    margin-bottom: 8px;
    font-family: var(--font-vn);
    font-size: 1rem;
}

.grammar-pattern {
    font-family: var(--font-jp);
    font-size: 1.35rem;
    color: var(--shu);
}

.grammar-meaning {
    margin-bottom: 6px;
    color: var(--ink-text);
}

.grammar-note {
    margin-bottom: 6px;
    color: var(--ink-muted);
    font-size: 0.9rem;
}

.grammar-example {
    grid-template-columns: minmax(0, 45%) minmax(0, 1fr) auto;
}

.grammar-example .learn-kana {
    font-size: 1.2rem;
}

/* Phones: Japanese on top, reading + meaning below, speaker on the right */
@media (max-width: 600px) {
    .learn-item,
    .grammar-example {
        grid-template-columns: minmax(0, 1fr) auto;
    }

    .learn-kana,
    .learn-text {
        grid-column: 1;
    }

    .learn-speak {
        grid-column: 2;
        grid-row: 1 / span 2;
    }

    .learn-kana {
        font-size: 1.35rem;
    }

    .grammar-example .learn-kana {
        font-size: 1.1rem;
    }

    .grammar-pattern {
        font-size: 1.15rem;
    }
}

.grammar-example:last-child {
    border-bottom: none;
}

/* Home */
.home-section {
    display: grid;
    grid-auto-rows: 1fr; /* equal-height cards */
    gap: 16px;
}

.home-card {
    display: flex;
    flex-direction: column;
    gap: 6px;
    padding: 28px 24px;
    text-align: left;
    background: var(--paper);
    color: var(--ink-text);
    border: 1px solid var(--ink-line);
    border-radius: 4px;
    box-shadow: var(--shadow-offset-sm);
    cursor: pointer;
    transition: border-color 0.2s, transform 0.1s;
}

.home-card:hover {
    border-color: var(--shu);
}

.home-card:active {
    transform: translate(2px, 2px);
}

.home-card-title {
    font-family: var(--font-jp);
    font-size: 1.6rem;
    font-weight: 700;
    color: var(--shu);
}

.home-card-desc {
    font-family: var(--font-vn);
    font-size: 0.9rem;
    color: var(--ink-muted);
}