/* ═══════════════════════════════════════════════════════════════════
   HSK Vocabulary Quiz — styles
   Hero: amber/gold #d97706  (distinct from teal, purple, indigo, rose)
   ═══════════════════════════════════════════════════════════════════ */

/* ── Hero ────────────────────────────────────────────────────────── */
.hsk-vocab-hero {
    background: linear-gradient(135deg, #d97706 0%, #b45309 100%);
    border-radius: 0.5rem;
}

/* ── Quiz card shadow ─────────────────────────────────────────────── */
.quiz-card {
    min-height: 420px;
}

/* ── HSK level badge ─────────────────────────────────────────────── */
.hsk-level-badge {
    font-size: 0.7rem;
    letter-spacing: 0.04em;
    padding: 0.25rem 0.55rem;
}

/* ── Character display ───────────────────────────────────────────── */
.char-display {
    font-size: 4rem;
    line-height: 1.1;
    letter-spacing: 0.05em;
    color: #1e293b;
}

.pinyin-display {
    font-size: 1.25rem;
    color: #64748b;
    font-style: italic;
}

/* ── Answer option buttons ───────────────────────────────────────── */
.vocab-option-btn {
    min-height: 58px;
    font-size: 0.95rem;
    font-weight: 500;
    border-width: 2px;
    transition: transform 0.12s, box-shadow 0.12s, background-color 0.15s, border-color 0.15s;
    text-align: left;
    padding: 0.6rem 1rem;
}

.vocab-option-btn:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.12);
}

.vocab-option-btn.correct {
    border-color: #198754 !important;
    background-color: #d1e7dd !important;
    color: #0a3622 !important;
}

.vocab-option-btn.incorrect {
    border-color: #dc3545 !important;
    background-color: #f8d7da !important;
    color: #58151c !important;
}

/* Option letter label (A / B / C / D) */
.option-letter {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 1.6rem;
    height: 1.6rem;
    border-radius: 50%;
    background: #e2e8f0;
    font-size: 0.75rem;
    font-weight: 700;
    margin-right: 0.6rem;
    flex-shrink: 0;
    transition: background-color 0.15s;
}

.vocab-option-btn.correct .option-letter {
    background: #198754;
    color: #fff;
}

.vocab-option-btn.incorrect .option-letter {
    background: #dc3545;
    color: #fff;
}

/* ── Difficulty badge ─────────────────────────────────────────────── */
.difficulty-badge {
    font-size: 0.78rem;
}

/* ── Score display (results) ─────────────────────────────────────── */
.score-display {
    font-size: 3rem;
    font-weight: 700;
    line-height: 1;
}

.results-card {
    border-radius: 0.75rem;
}

/* ── Sidebar panel header ─────────────────────────────────────────── */
.panel-header {
    background: linear-gradient(135deg, #d97706 0%, #b45309 100%);
    color: #fff;
    border-radius: 0.375rem 0.375rem 0 0;
}

/* ── HSK level row in sidebar ─────────────────────────────────────── */
.hsk-level-item {
    border-bottom: 1px solid #f1f5f9;
    padding: 0.35rem 0;
}

.hsk-level-item:last-child {
    border-bottom: none;
}