@import url('https://fonts.googleapis.com/css2?family=Outfit:wght@300;400;500;600;700;800&family=Noto+Sans+KR:wght@400;500;700&display=swap');

/* ========== DESIGN TOKENS ========== */
:root {
    --bg-primary: #0f0a0a;
    --bg-secondary: #1a0a0a;
    --bg-card: rgba(30, 10, 10, 0.7);
    --bg-card-hover: rgba(50, 15, 15, 0.8);
    --glass-border: rgba(230, 57, 70, 0.15);
    --glass-shadow: 0 8px 32px rgba(0, 0, 0, 0.4);

    --accent-primary: #E63946;
    --accent-secondary: #FF6B7A;
    --accent-glow: rgba(230, 57, 70, 0.3);
    --accent-gradient: linear-gradient(135deg, #E63946 0%, #C0392B 100%);
    --accent-gradient-hover: linear-gradient(135deg, #C0392B 0%, #E63946 100%);

    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;

    --correct-bg: rgba(52, 211, 153, 0.15);
    --correct-border: #34d399;
    --incorrect-bg: rgba(251, 113, 133, 0.15);
    --incorrect-border: #fb7185;
    --neutral-bg: rgba(148, 163, 184, 0.1);
    --neutral-border: rgba(148, 163, 184, 0.3);

    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --radius-xl: 28px;

    --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-smooth: 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

/* ========== RESET & BASE ========== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

body {
    font-family: 'Outfit', 'Noto Sans KR', sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 24px 16px;
    overflow-x: hidden;
    position: relative;
}

body::before {
    content: '';
    position: fixed;
    top: -50%; left: -50%;
    width: 200%; height: 200%;
    background:
        radial-gradient(ellipse at 20% 50%, rgba(230, 57, 70, 0.06) 0%, transparent 50%),
        radial-gradient(ellipse at 80% 20%, rgba(192, 57, 43, 0.04) 0%, transparent 50%),
        radial-gradient(ellipse at 50% 80%, rgba(230, 57, 70, 0.03) 0%, transparent 50%);
    animation: bgShift 20s ease-in-out infinite alternate;
    z-index: -1;
}

@keyframes bgShift {
    0% { transform: translate(0, 0) rotate(0deg); }
    100% { transform: translate(-5%, -5%) rotate(3deg); }
}

/* ========== STARS ========== */
.stars { position: fixed; top: 0; left: 0; width: 100%; height: 100%; pointer-events: none; z-index: -1; }
.star { position: absolute; width: 2px; height: 2px; background: white; border-radius: 50%; animation: twinkle var(--duration) ease-in-out infinite alternate; opacity: 0; }
@keyframes twinkle { 0% { opacity: 0; transform: scale(0.5); } 100% { opacity: var(--max-opacity); transform: scale(1); } }

/* ========== HERO ========== */
.hero { text-align: center; margin-bottom: 8px; }

.hero-icon {
    font-size: 4rem;
    margin-bottom: 8px;
    animation: heroFloat 4s ease-in-out infinite;
    filter: drop-shadow(0 0 20px var(--accent-glow));
}

@keyframes heroFloat { 0%, 100% { transform: translateY(0); } 50% { transform: translateY(-8px); } }

.hero h1 {
    font-family: 'Outfit', sans-serif;
    font-size: 2.2rem;
    font-weight: 800;
    background: linear-gradient(135deg, #f1f5f9, #E63946);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    line-height: 1.2;
    margin-bottom: 8px;
}

/* ========== GLASS CARD ========== */
.glass-card {
    width: 100%; max-width: 640px;
    background: var(--bg-card);
    backdrop-filter: blur(16px); -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-xl);
    padding: 32px;
    box-shadow: var(--glass-shadow);
    transition: border-color var(--transition-smooth);
}
.glass-card:hover { border-color: rgba(230, 57, 70, 0.3); }

/* ========== FORM OPTIONS ========== */
.option-section { margin-bottom: 28px; }
.option-section:last-of-type { margin-bottom: 0; }
.option-label { display: flex; align-items: center; gap: 8px; font-size: 0.85rem; font-weight: 600; color: var(--text-secondary); text-transform: uppercase; letter-spacing: 0.08em; margin-bottom: 12px; }
.option-label-icon { font-size: 1.1rem; }
.option-group { display: flex; gap: 8px; flex-wrap: wrap; }
.option-group input[type="radio"] { display: none; }
.option-group label { flex: 1; min-width: 80px; padding: 12px 16px; border-radius: var(--radius-md); background: var(--neutral-bg); border: 1.5px solid var(--neutral-border); color: var(--text-secondary); font-family: 'Outfit', 'Noto Sans KR', sans-serif; font-size: 0.95rem; font-weight: 500; text-align: center; cursor: pointer; transition: all var(--transition-fast); }
.option-group label:hover { background: rgba(230, 57, 70, 0.08); border-color: rgba(230, 57, 70, 0.3); color: var(--text-primary); }
.option-group input[type="radio"]:checked + label { background: var(--accent-gradient); border-color: transparent; color: white; font-weight: 600; box-shadow: 0 4px 15px var(--accent-glow); transform: translateY(-1px); }

/* ========== CTA BUTTON ========== */
.cta-button {
    width: 100%; padding: 16px;
    font-family: 'Outfit', 'Noto Sans KR', sans-serif; font-size: 1.15rem; font-weight: 700;
    color: white; background: var(--accent-gradient);
    border: none; border-radius: var(--radius-lg);
    cursor: pointer; transition: all var(--transition-fast);
    box-shadow: 0 4px 20px var(--accent-glow); margin-top: 28px;
    position: relative; overflow: hidden;
}
.cta-button::before { content: ''; position: absolute; top: 0; left: -100%; width: 100%; height: 100%; background: linear-gradient(90deg, transparent, rgba(255,255,255,0.15), transparent); transition: left 0.5s; }
.cta-button:hover::before { left: 100%; }
.cta-button:hover { transform: translateY(-2px); box-shadow: 0 8px 30px var(--accent-glow); }
.cta-button:active { transform: translateY(0) scale(0.98); }

/* ========== CHART TOGGLE ========== */
.chart-toggle {
    width: 100%; max-width: 640px;
    display: flex; align-items: center; justify-content: space-between;
    padding: 20px 28px;
    background: var(--bg-card); backdrop-filter: blur(16px); -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--glass-border); border-radius: var(--radius-xl);
    cursor: pointer; transition: all var(--transition-fast); margin-top: 24px;
}
.chart-toggle:hover { border-color: rgba(230, 57, 70, 0.3); }
.chart-toggle h2 { font-family: 'Outfit', sans-serif; font-size: 1.15rem; font-weight: 600; color: var(--text-primary); }
.chart-toggle-arrow { font-size: 1rem; color: var(--accent-primary); transition: transform var(--transition-smooth); }
.chart-toggle.expanded .chart-toggle-arrow { transform: rotate(180deg); }

.chart-panel { width: 100%; max-width: 640px; max-height: 0; overflow: hidden; transition: max-height 0.5s ease-in-out; }
.chart-panel.expanded { max-height: 5000px; }
.chart-panel-inner { padding-top: 16px; }

/* ========== CHART TABS ========== */
.chart-tabs { display: flex; gap: 8px; margin-bottom: 16px; }
.chart-tab { flex: 1; padding: 10px 12px; border-radius: var(--radius-md); background: var(--neutral-bg); border: 1.5px solid var(--neutral-border); color: var(--text-secondary); font-family: 'Outfit', 'Noto Sans KR', sans-serif; font-size: 0.88rem; font-weight: 600; cursor: pointer; transition: all var(--transition-fast); text-align: center; }
.chart-tab:hover { border-color: var(--accent-primary); color: var(--accent-primary); }
.chart-tab.active { background: var(--accent-gradient); border-color: transparent; color: white; }
.chart-box { display: none; }
.chart-box.active { display: block; }

/* ========== SECTION TITLE ========== */
.section-title { font-size: 0.85rem; font-weight: 600; color: var(--accent-primary); text-transform: uppercase; letter-spacing: 0.08em; text-align: center; padding-bottom: 8px; margin-bottom: 12px; border-bottom: 1px solid var(--glass-border); }

/* ========== WORD GRID (HOME PREVIEW) ========== */
.word-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 6px; margin-bottom: 16px; }

.word-cell {
    display: flex; justify-content: center; align-items: center;
    min-height: 48px; padding: 8px 6px;
    border-radius: var(--radius-sm);
    font-family: 'Outfit', sans-serif; font-size: 0.78rem; font-weight: 600;
    background: var(--neutral-bg); border: 1.5px solid var(--neutral-border);
    color: var(--text-primary); cursor: pointer;
    transition: all var(--transition-fast); user-select: none;
    text-align: center; word-break: break-word; line-height: 1.3;
}
.word-cell:hover { background: rgba(230, 57, 70, 0.15); border-color: var(--accent-primary); transform: translateY(-2px); box-shadow: 0 4px 12px var(--accent-glow); }
.word-cell.show-kr { font-family: 'Noto Sans KR', sans-serif; font-size: 0.75rem; color: var(--accent-primary); }
.word-cell.fade-out { opacity: 0; transition: opacity 0.3s ease-in-out; }

/* ========== QUIZ ========== */
.quiz-container {
    width: 100%; max-width: 640px;
    background: var(--bg-card); backdrop-filter: blur(16px); -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--glass-border); border-radius: var(--radius-xl);
    padding: 32px; box-shadow: var(--glass-shadow); text-align: center;
    transition: border-color var(--transition-smooth);
}
.progress-bar { width: 100%; height: 6px; background: rgba(148, 163, 184, 0.15); border-radius: 3px; overflow: hidden; margin-bottom: 8px; }
.progress-bar-inner { height: 100%; width: 0%; background: var(--accent-gradient); border-radius: 3px; transition: width 0.4s ease; }
.progress-text { font-size: 0.85rem; font-weight: 500; color: var(--text-muted); margin-bottom: 24px; }
.question-display {
    font-family: 'Outfit', sans-serif; font-size: 2.8rem; font-weight: 700;
    color: var(--text-primary); min-height: 160px;
    display: flex; justify-content: center; align-items: center;
    text-shadow: 0 0 60px var(--accent-glow);
    opacity: 1; transition: opacity 0.3s ease-in-out;
    cursor: pointer; text-align: center; word-break: break-word; line-height: 1.3; padding: 12px 0;
}
.question-display.fade-out { opacity: 0; }
.question-display.show-answer { font-family: 'Noto Sans KR', sans-serif; font-size: 2.8rem; color: var(--accent-primary); }
.answer-input {
    width: 100%; max-width: 360px; padding: 14px 20px;
    font-family: 'Outfit', 'Noto Sans KR', sans-serif; font-size: 1.3rem; font-weight: 500;
    text-align: center; background: rgba(30, 41, 59, 0.6);
    border: 2px solid var(--neutral-border); border-radius: var(--radius-md);
    color: var(--text-primary); outline: none;
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}
.answer-input:focus { border-color: var(--accent-primary); box-shadow: 0 0 0 3px var(--accent-glow); }
.answer-input::placeholder { color: var(--text-muted); }
.button-container { display: flex; gap: 12px; margin-top: 24px; }
.quiz-nav-button {
    flex: 1; padding: 12px 20px; border-radius: var(--radius-md);
    font-family: 'Outfit', 'Noto Sans KR', sans-serif; font-size: 0.95rem; font-weight: 600;
    cursor: pointer; transition: all var(--transition-fast); border: 1.5px solid transparent;
    text-align: center; text-decoration: none;
    background: var(--accent-gradient); color: white; box-shadow: 0 4px 15px var(--accent-glow);
}
.quiz-nav-button:hover { transform: translateY(-1px); box-shadow: 0 6px 20px var(--accent-glow); }
.quiz-nav-button.secondary { background: transparent; border-color: var(--neutral-border); color: var(--text-secondary); box-shadow: none; }
.quiz-nav-button.secondary:hover { border-color: var(--accent-primary); color: var(--accent-primary); background: rgba(230, 57, 70, 0.05); }
.feedback-correct { animation: flash-correct 0.5s; }
.feedback-incorrect { animation: flash-incorrect 0.5s; }
@keyframes flash-correct { 50% { background-color: var(--correct-bg); border-color: var(--correct-border); } }
@keyframes flash-incorrect { 50% { background-color: var(--incorrect-bg); border-color: var(--incorrect-border); } }

/* ========== RESULT ========== */
.result-container {
    width: 100%; max-width: 800px;
    background: var(--bg-card); backdrop-filter: blur(16px); -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--glass-border); border-radius: var(--radius-xl);
    padding: 32px; box-shadow: var(--glass-shadow); text-align: center;
}
.result-container h1 { font-family: 'Outfit', sans-serif; font-size: 1.5rem; font-weight: 700; margin-bottom: 4px; background: none; -webkit-text-fill-color: var(--text-primary); }
.score { font-family: 'Outfit', sans-serif; font-size: 3rem; font-weight: 800; background: linear-gradient(135deg, #34d399, #E63946); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; margin: 16px 0; }
.legend { display: flex; justify-content: center; gap: 20px; margin-bottom: 28px; flex-wrap: wrap; }
.legend-item { display: flex; align-items: center; gap: 6px; font-size: 0.85rem; color: var(--text-secondary); }
.legend-color { width: 12px; height: 12px; border-radius: 3px; }
.chart-container { margin-top: 20px; }
.chart-container h3 { font-size: 0.85rem; font-weight: 600; color: var(--accent-primary); text-transform: uppercase; letter-spacing: 0.08em; text-align: center; padding-bottom: 8px; margin-bottom: 12px; border-bottom: 1px solid var(--glass-border); }

.word-result-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(120px, 1fr)); gap: 8px; margin-bottom: 24px; }

.char-cell {
    display: flex; justify-content: center; align-items: center;
    min-height: 52px; padding: 10px 8px;
    border-radius: var(--radius-sm);
    font-family: 'Outfit', sans-serif; font-size: 0.88rem; font-weight: 600;
    background: var(--neutral-bg); border: 1.5px solid var(--neutral-border);
    color: var(--text-primary); cursor: pointer; transition: all var(--transition-fast);
    user-select: none; text-align: center; word-break: break-word; line-height: 1.3;
}
.char-cell:hover { background: rgba(230, 57, 70, 0.15); border-color: var(--accent-primary); transform: translateY(-2px); box-shadow: 0 4px 12px var(--accent-glow); }
.char-cell.correct { background: var(--correct-bg); border-color: var(--correct-border); }
.char-cell.incorrect { background: var(--incorrect-bg); border-color: var(--incorrect-border); }
.char-cell.not-asked { opacity: 0.5; }
.char-cell.show-kr { font-family: 'Noto Sans KR', sans-serif; font-size: 0.78rem; color: var(--accent-primary); }
.char-cell.fade-out { opacity: 0; transition: opacity 0.3s ease-in-out; }

.retry-button {
    display: inline-block; width: 100%; padding: 16px;
    font-family: 'Outfit', 'Noto Sans KR', sans-serif; font-size: 1.15rem; font-weight: 700;
    color: white; background: var(--accent-gradient); border: none; border-radius: var(--radius-lg);
    text-decoration: none; cursor: pointer; transition: all var(--transition-fast);
    box-shadow: 0 4px 20px var(--accent-glow); margin-top: 32px; position: relative; overflow: hidden;
}
.retry-button:hover { transform: translateY(-2px); box-shadow: 0 8px 30px var(--accent-glow); }

/* ========== AD ========== */
.ad-grid { display: grid; grid-template-columns: repeat(2, 320px); gap: 12px; justify-content: center; margin-top: 20px; }
.ad-mobile-container-320-100-center { display: block; width: 320px; height: 100px; }
@media (max-width: 680px) { .ad-grid { grid-template-columns: 320px; } }

/* ========== TITLE BAR ========== */
.title-bar { display: flex; align-items: center; justify-content: space-between; width: 100%; max-width: 680px; padding: 4px 0 12px; }
.title-bar__home { display: flex; align-items: center; gap: 6px; text-decoration: none; color: var(--text-secondary); font-size: 0.88rem; font-weight: 600; transition: color var(--transition-fast); }
.title-bar__home:hover { color: var(--accent-primary); }
.title-bar__cat { font-size: 0.82rem; font-weight: 700; color: var(--accent-primary); background: rgba(230, 57, 70, 0.12); border: 1px solid rgba(230, 57, 70, 0.3); padding: 4px 14px; border-radius: 20px; white-space: nowrap; }

/* ========== FEATURE CARDS ========== */
.feature-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; width: 100%; max-width: 680px; margin-top: 16px; }
.feature-card { background: var(--bg-card); backdrop-filter: blur(16px); -webkit-backdrop-filter: blur(16px); border: 1px solid var(--glass-border); border-radius: var(--radius-xl); padding: 24px 20px; transition: border-color var(--transition-smooth); display: flex; flex-direction: column; }
.feature-card:hover { border-color: rgba(230, 57, 70, 0.3); }
.feature-icon { font-size: 2.2rem; margin-bottom: 10px; }
.feature-title { font-family: 'Outfit', sans-serif; font-size: 1.1rem; font-weight: 700; color: var(--text-primary); margin-bottom: 6px; }
.feature-desc { font-size: 0.82rem; color: var(--text-secondary); line-height: 1.5; margin-bottom: 16px; flex: 1; }
.card-actions { display: flex; flex-direction: column; gap: 8px; }
.btn-link { display: block; padding: 9px 14px; border-radius: var(--radius-md); text-decoration: none; font-family: 'Outfit', 'Noto Sans KR', sans-serif; font-size: 0.88rem; font-weight: 600; text-align: center; transition: all var(--transition-fast); background: var(--neutral-bg); border: 1.5px solid var(--neutral-border); color: var(--text-secondary); }
.btn-link:hover { border-color: var(--accent-primary); color: var(--accent-primary); background: rgba(230, 57, 70, 0.08); transform: translateY(-1px); }
.btn-link.primary { background: var(--accent-gradient); border-color: transparent; color: white; box-shadow: 0 4px 15px var(--accent-glow); }
.btn-link.primary:hover { transform: translateY(-2px); box-shadow: 0 6px 20px var(--accent-glow); color: white; }

/* ========== PAGE CONTAINER ========== */
.page-container { width: 100%; max-width: 680px; display: flex; flex-direction: column; align-items: stretch; gap: 0; }
.page-header { text-align: center; margin-bottom: 20px; }
.page-title { font-family: 'Outfit', sans-serif; font-size: 1.6rem; font-weight: 800; color: var(--text-primary); margin-bottom: 4px; }
.page-sub { font-size: 0.9rem; color: var(--text-secondary); }

/* ========== SUBNAV ========== */
.subnav { display: flex; gap: 8px; width: 100%; margin-bottom: 20px; }
.subnav-btn { flex: 1; padding: 10px 12px; border-radius: var(--radius-md); text-decoration: none; font-family: 'Outfit', 'Noto Sans KR', sans-serif; font-size: 0.88rem; font-weight: 600; text-align: center; background: var(--neutral-bg); border: 1.5px solid var(--neutral-border); color: var(--text-secondary); cursor: pointer; transition: all var(--transition-fast); }
.subnav-btn:hover { border-color: var(--accent-primary); color: var(--accent-primary); }
.subnav-btn.active { background: var(--accent-gradient); border-color: transparent; color: white; pointer-events: none; }

/* ========== SETTINGS FORM ========== */
.settings-form { background: var(--bg-card); backdrop-filter: blur(16px); -webkit-backdrop-filter: blur(16px); border: 1px solid var(--glass-border); border-radius: var(--radius-xl); padding: 24px; box-shadow: var(--glass-shadow); margin-bottom: 16px; }
.settings-form fieldset { border: none; padding: 0; margin-bottom: 20px; }
.settings-form fieldset:last-of-type { margin-bottom: 0; }
.settings-form legend { font-size: 0.82rem; font-weight: 600; color: var(--text-secondary); text-transform: uppercase; letter-spacing: 0.08em; margin-bottom: 10px; }
.scroll-group { display: flex; gap: 6px; flex-wrap: wrap; }
.scroll-group input[type="radio"] { display: none; }
.scroll-group label { padding: 8px 14px; border-radius: var(--radius-sm); background: var(--neutral-bg); border: 1.5px solid var(--neutral-border); color: var(--text-secondary); font-family: 'Outfit', 'Noto Sans KR', sans-serif; font-size: 0.88rem; font-weight: 500; cursor: pointer; transition: all var(--transition-fast); white-space: nowrap; }
.scroll-group label:hover { border-color: var(--accent-primary); color: var(--accent-primary); }
.scroll-group input[type="radio"]:checked + label { background: var(--accent-gradient); border-color: transparent; color: white; font-weight: 600; box-shadow: 0 3px 10px var(--accent-glow); }
.scroll-group label.tbd { opacity: 0.4; cursor: not-allowed; }
.start-button { width: 100%; padding: 14px; font-family: 'Outfit', 'Noto Sans KR', sans-serif; font-size: 1.05rem; font-weight: 700; color: white; background: var(--accent-gradient); border: none; border-radius: var(--radius-lg); cursor: pointer; transition: all var(--transition-fast); box-shadow: 0 4px 20px var(--accent-glow); margin-top: 20px; }
.start-button:hover { transform: translateY(-2px); box-shadow: 0 8px 28px var(--accent-glow); }

/* ========== WORDBOOK ========== */
.layout-controls { display: flex; gap: 8px; margin-bottom: 12px; }
.layout-btn { padding: 8px 14px; border-radius: var(--radius-sm); background: var(--neutral-bg); border: 1.5px solid var(--neutral-border); color: var(--text-secondary); font-family: 'Outfit', 'Noto Sans KR', sans-serif; font-size: 0.85rem; font-weight: 600; cursor: pointer; transition: all var(--transition-fast); }
.layout-btn:hover { border-color: var(--accent-primary); color: var(--accent-primary); }
.layout-btn.active { background: var(--accent-gradient); border-color: transparent; color: white; }
.wordbook-list { display: grid; gap: 6px; width: 100%; }
.wordbook-list.cols-1 { grid-template-columns: 1fr; }
.wordbook-list.cols-3 { grid-template-columns: repeat(3, 1fr); }
.wordbook-list.cols-5 { grid-template-columns: repeat(5, 1fr); }
.wb-row { display: flex; align-items: center; gap: 8px; padding: 10px 14px; border-radius: var(--radius-sm); background: var(--bg-card); border: 1.5px solid var(--glass-border); cursor: pointer; transition: all var(--transition-fast); min-height: 44px; }
.wb-row:hover { border-color: var(--accent-primary); background: var(--bg-card-hover); }
.cols-3 .wb-row, .cols-5 .wb-row { flex-direction: column; align-items: center; text-align: center; gap: 4px; padding: 10px 8px; }
.wb-idx { font-size: 0.75rem; color: var(--text-muted); min-width: 24px; }
.cols-3 .wb-idx, .cols-5 .wb-idx { font-size: 0.7rem; min-width: auto; }
.wb-en { font-family: 'Outfit', sans-serif; font-size: 1rem; font-weight: 600; color: var(--text-primary); flex: 1; word-break: break-word; }
.cols-3 .wb-en, .cols-5 .wb-en { font-size: 0.88rem; flex: none; }
.wb-kr { font-family: 'Noto Sans KR', sans-serif; font-size: 0.9rem; color: var(--accent-primary); font-weight: 500; }
.cols-3 .wb-kr, .cols-5 .wb-kr { font-size: 0.8rem; }
.wb-hidden { visibility: hidden; height: 0; overflow: hidden; padding: 0; margin: 0; }
.cols-3 .wb-hidden, .cols-5 .wb-hidden { display: none; }

/* ========== FLASHCARD ========== */
.fc-wrapper { perspective: 1000px; width: 100%; max-width: 480px; margin: 0 auto 16px; }
.fc-card { position: relative; width: 100%; padding-top: 60%; transform-style: preserve-3d; transition: transform 0.45s ease; cursor: pointer; }
.fc-card.flipped { transform: rotateY(180deg); }
.fc-front, .fc-back { position: absolute; inset: 0; display: flex; flex-direction: column; justify-content: center; align-items: center; gap: 8px; border-radius: var(--radius-xl); background: var(--bg-card); backdrop-filter: blur(16px); -webkit-backdrop-filter: blur(16px); border: 1.5px solid var(--glass-border); box-shadow: var(--glass-shadow); backface-visibility: hidden; -webkit-backface-visibility: hidden; padding: 20px; text-align: center; }
.fc-back { transform: rotateY(180deg); border-color: rgba(230, 57, 70, 0.3); }
.fc-counter { position: absolute; top: 14px; right: 18px; font-size: 0.78rem; font-weight: 600; color: var(--text-muted); }
.fc-word { font-family: 'Outfit', sans-serif; font-size: 2rem; font-weight: 700; color: var(--text-primary); text-shadow: 0 0 40px var(--accent-glow); word-break: break-word; line-height: 1.3; }
.fc-meaning { font-family: 'Noto Sans KR', sans-serif; font-size: 1.6rem; font-weight: 700; color: var(--accent-primary); word-break: break-word; line-height: 1.3; }
.fc-tap-hint { font-size: 0.78rem; color: var(--text-muted); margin-top: 4px; }
.fc-progress-wrap { width: 100%; max-width: 480px; margin: 0 auto 12px; }
.fc-progress-bar { width: 100%; height: 5px; background: rgba(148, 163, 184, 0.15); border-radius: 3px; overflow: hidden; }
.fc-progress-inner { height: 100%; background: var(--accent-gradient); border-radius: 3px; transition: width 0.35s ease; }
.fc-nav { display: flex; gap: 8px; width: 100%; max-width: 480px; margin: 0 auto 16px; }
.fc-nav-btn { flex: 1; padding: 10px 12px; border-radius: var(--radius-md); background: var(--neutral-bg); border: 1.5px solid var(--neutral-border); color: var(--text-secondary); font-family: 'Outfit', 'Noto Sans KR', sans-serif; font-size: 0.88rem; font-weight: 600; cursor: pointer; transition: all var(--transition-fast); }
.fc-nav-btn:hover { border-color: var(--accent-primary); color: var(--accent-primary); transform: translateY(-1px); }
.fc-control-bar { display: flex; align-items: stretch; justify-content: space-between; gap: 8px; width: 100%; max-width: 480px; margin: 0 auto; padding: 6px 10px; background: rgba(255,255,255,0.03); border-radius: var(--radius-sm); border: 1px solid var(--glass-border); }
.fc-play-btn { flex: 1; display: flex; align-items: center; justify-content: center; gap: 8px; padding: 8px; background: transparent; border: none; cursor: pointer; color: var(--text-primary); transition: all var(--transition-fast); border-radius: var(--radius-sm); }
.fc-play-btn:hover { background: rgba(230, 57, 70, 0.12); }
.fc-divider { width: 1px; background: var(--glass-border); margin: 4px 0; }
.fc-speed-group { display: flex; gap: 4px; align-items: center; }
.speed-btn { padding: 5px 10px; border-radius: var(--radius-sm); background: transparent; border: 1.5px solid var(--neutral-border); color: var(--text-muted); font-family: 'Outfit', sans-serif; font-size: 0.78rem; font-weight: 600; cursor: pointer; transition: all var(--transition-fast); }
.speed-btn:hover { border-color: var(--accent-primary); color: var(--accent-primary); }
.speed-btn.active { background: var(--accent-gradient); border-color: transparent; color: white; }

/* ========== RESPONSIVE ========== */
@media (max-width: 600px) { .feature-grid { grid-template-columns: 1fr; } }
@media (max-width: 480px) {
    .hero h1 { font-size: 1.7rem; }
    .hero-icon { font-size: 3rem; }
    .glass-card, .quiz-container, .result-container { padding: 24px 20px; }
    .question-display, .question-display.show-answer { font-size: 2rem; min-height: 130px; }
    .score { font-size: 2.2rem; }
    .fc-word { font-size: 1.5rem; }
    .fc-meaning { font-size: 1.3rem; }
    .wordbook-list.cols-5 { grid-template-columns: repeat(3, 1fr); }
    .word-grid { grid-template-columns: repeat(3, 1fr); }
    .word-result-grid { grid-template-columns: repeat(auto-fill, minmax(90px, 1fr)); }
}