/* ══════════════════════════════════════════════════════════════════
   PMP Quiz — 산업안전/보건/공인노무사 Quiz와 통day된 디자인
   Palette : Bright Blue (#2563EB) + Purple accent + White
   Hero    : Indigo → Purple gradient
   Font    : Pretendard (KR) + Inter (EN)
   모든 기존 클래스명은 그대로 유지되어 HTML 템플릿 수정 불필요
   ══════════════════════════════════════════════════════════════════ */

@import url('https://cdn.jsdelivr.net/gh/orioncactus/pretendard@v1.3.9/dist/web/variable/pretendardvariable-dynamic-subset.css');
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&display=swap');

/* ── Design Tokens ─────────────────────────────────────────────── */
:root {
    /* Brand (맞춤: safety-quiz 팔레트) */
    --primary:        #2563EB;
    --primary-dark:   #1D4ED8;
    --primary-soft:   #DBEAFE;
    --primary-line:   #BFDBFE;
    --accent:         #7C3AED;
    --accent-soft:    #EDE9FE;
    --purple:         #7C3AED;
    --purple-soft:    #EDE9FE;

    /* Hero gradient (safety-quiz와 동day) */
    --hero-gradient:  linear-gradient(135deg, #1E3A8A 0%, #5B21B6 100%);

    /* Semantic */
    --success:        #059669;
    --success-soft:   #ECFDF5;
    --success-line:   #A7F3D0;
    --danger:         #DC2626;
    --danger-soft:    #FEF2F2;
    --danger-line:    #FECACA;
    --warning:        #D97706;
    --warning-soft:   #FFFBEB;
    --warning-line:   #FDE68A;
    --info:           #0891B2;
    --info-soft:      #ECFEFF;

    /* Neutral */
    --bg:             #F8FAFC;
    --surface:        #FFFFFF;
    --card-bg:        #FFFFFF;
    --surface-alt:    #F4F6FA;
    --border:         #E4E7EC;
    --border-strong:  #D0D5DD;
    --text:           #101828;
    --text-muted:     #475467;
    --text-subtle:    #667085;
    --text-faint:     #98A2B3;

    /* Radii */
    --r-sm: 8px;
    --r-md: 10px;
    --r-lg: 14px;
    --r-xl: 20px;
    --radius:    14px;
    --radius-sm: 8px;

    /* Shadow (Notion/Linear soft) */
    --shadow-xs: 0 1px 2px rgba(16, 24, 40, .04);
    --shadow-sm: 0 1px 3px rgba(16, 24, 40, .06), 0 1px 2px rgba(16, 24, 40, .04);
    --shadow-md: 0 4px 10px -2px rgba(16, 24, 40, .06), 0 2px 6px -2px rgba(16, 24, 40, .04);
    --shadow-lg: 0 12px 24px -6px rgba(16, 24, 40, .10), 0 4px 8px -4px rgba(16, 24, 40, .05);
    --shadow-xl: 0 24px 48px -12px rgba(16, 24, 40, .18);
    --shadow:    var(--shadow-sm);

    /* Focus ring */
    --ring: 0 0 0 4px rgba(30, 64, 175, .12);
}

/* ── Reset & Base ──────────────────────────────────────────────── */
* { box-sizing: border-box; margin: 0; padding: 0; }

html, body {
    background: var(--bg);
    color: var(--text);
    font-family: 'Pretendard Variable', 'Pretendard', 'Inter',
                 -apple-system, BlinkMacSystemFont, 'Segoe UI',
                 Roboto, 'Helvetica Neue', Arial, sans-serif;
    font-size: 15px;
    line-height: 1.6;
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    letter-spacing: -0.01em;
}

h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    letter-spacing: -0.02em;
    color: var(--text);
    line-height: 1.3;
}

h1 { font-size: 1.75rem; }
h2 { font-size: 1.35rem; }
h3 { font-size: 1.1rem; }

a { color: var(--primary); text-decoration: none; }
a:hover { color: var(--primary-dark); }

::selection { background: var(--primary-soft); color: var(--primary-dark); }

/* ── Navbar ────────────────────────────────────────────────────── */
.navbar {
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: saturate(180%) blur(14px);
    -webkit-backdrop-filter: saturate(180%) blur(14px);
    border-bottom: 1px solid var(--border);
    padding: 0 20px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 60px;
    position: sticky;
    top: 0;
    z-index: 100;
}

.navbar-brand {
    color: var(--text);
    font-size: 1.05rem;
    font-weight: 700;
    letter-spacing: -0.02em;
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 8px;
}

.navbar-brand i {
    color: var(--primary);
    font-size: 1.2rem;
}

.navbar-nav {
    display: flex;
    list-style: none;
    gap: 2px;
    align-items: center;
}

.navbar-nav a {
    color: var(--text-muted);
    text-decoration: none;
    padding: 8px 12px;
    border-radius: var(--r-sm);
    font-size: 0.9rem;
    font-weight: 500;
    transition: all 0.15s ease;
    white-space: nowrap;
    display: inline-flex;
    align-items: center;
    gap: 6px;
}

.navbar-nav a:hover {
    background: var(--surface-alt);
    color: var(--text);
}

.navbar-nav a.active {
    background: var(--primary-soft);
    color: var(--primary);
}

.navbar-nav a.active i {
    color: var(--primary);
}

.hamburger {
    display: none;
    background: none;
    border: none;
    color: var(--text);
    font-size: 1.3rem;
    cursor: pointer;
    padding: 4px 8px;
    border-radius: var(--r-sm);
}
.hamburger:hover { background: var(--surface-alt); }

/* ── Dark Mode Toggle ──────────────────────────────────────────── */
.dark-toggle {
    background: var(--surface-alt);
    border: 1px solid var(--border);
    color: var(--text-muted);
    border-radius: 999px;
    padding: 5px 12px;
    cursor: pointer;
    font-size: 0.8rem;
    font-weight: 500;
    display: inline-flex;
    align-items: center;
    gap: 5px;
    transition: all 0.15s ease;
    white-space: nowrap;
}
.dark-toggle:hover {
    background: var(--surface);
    border-color: var(--border-strong);
    color: var(--text);
}

/* ── Main Content ──────────────────────────────────────────────── */
.main-content {
    max-width: 1180px;
    margin: 0 auto;
    padding: 28px 20px 40px;
}

/* ── Hero Banner (safety-quiz style) ───────────────────────────── */
.hero {
    background: var(--hero-gradient);
    color: #fff;
    border-radius: 20px;
    padding: 44px 40px;
    margin-bottom: 28px;
    position: relative;
    overflow: hidden;
}
.hero::after {
    content: "";
    position: absolute;
    right: -60px;
    bottom: -60px;
    width: 260px;
    height: 260px;
    background: radial-gradient(circle, rgba(255, 255, 255, .12), transparent 70%);
    border-radius: 50%;
    pointer-events: none;
}
.hero h1 {
    margin: 0 0 8px;
    font-size: 32px;
    font-weight: 800;
    letter-spacing: -.5px;
    color: #fff;
}
.hero p {
    margin: 0;
    opacity: .92;
    font-size: 15px;
    max-width: 640px;
}
.hero .badges {
    display: flex;
    gap: 10px;
    margin-top: 18px;
    flex-wrap: wrap;
}
.hero .badges span {
    background: rgba(255, 255, 255, .16);
    backdrop-filter: blur(6px);
    padding: 6px 14px;
    border-radius: 999px;
    font-size: 13px;
    font-weight: 600;
    color: #fff;
    display: inline-flex;
    align-items: center;
    gap: 6px;
}
@media (max-width: 640px) {
    .hero { padding: 32px 22px; border-radius: 16px; }
    .hero h1 { font-size: 24px; }
    .hero p { font-size: 14px; }
}

/* ── Section Title (pill tag) ──────────────────────────────────── */
.section-title {
    display: flex;
    align-items: center;
    gap: 10px;
    margin: 28px 0 14px;
    font-size: 1.05rem;
    font-weight: 700;
    color: var(--text);
    letter-spacing: -0.01em;
}
.section-title .tag {
    display: inline-block;
    background: var(--primary-soft);
    color: var(--primary-dark);
    padding: 4px 10px;
    border-radius: 999px;
    font-size: 12px;
    font-weight: 700;
}
.section-title .tag.purple { background: var(--purple-soft); color: var(--purple); }
.section-title .tag.green { background: var(--success-soft); color: var(--success); }
.section-title .tag.warn { background: var(--warning-soft); color: var(--warning); }

/* ── Cards ─────────────────────────────────────────────────────── */
.card {
    background: var(--surface);
    border-radius: var(--r-lg);
    box-shadow: var(--shadow-sm);
    padding: 24px;
    margin-bottom: 20px;
    border: 1px solid var(--border);
    transition: border-color 0.15s ease, box-shadow 0.15s ease;
}

.card-header {
    font-size: 1rem;
    font-weight: 700;
    letter-spacing: -0.01em;
    margin-bottom: 18px;
    padding-bottom: 14px;
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    gap: 8px;
    color: var(--text);
}

.card-header i { color: var(--primary); font-size: 0.95rem; }

/* ── Stats Grid ────────────────────────────────────────────────── */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 14px;
    margin-bottom: 24px;
}

.stat-card {
    background: var(--surface);
    border-radius: var(--r-lg);
    padding: 20px 22px;
    box-shadow: var(--shadow-xs);
    border: 1px solid var(--border);
    transition: transform 0.15s ease, box-shadow 0.15s ease, border-color 0.15s ease;
    position: relative;
    overflow: hidden;
}

.stat-card::before {
    content: '';
    position: absolute;
    inset: 0 0 auto 0;
    height: 3px;
    background: linear-gradient(90deg, var(--primary), var(--accent));
    opacity: 0;
    transition: opacity 0.2s ease;
}

.stat-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
    border-color: var(--primary-line);
}
.stat-card:hover::before { opacity: 1; }

/* Icon badge for stat-card / menu cards (safety-quiz 스타day) */
.icon-badge {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border-radius: 10px;
    font-size: 20px;
    margin-bottom: 12px;
}
.ib-blue   { background: var(--primary-soft); color: var(--primary-dark); }
.ib-purple { background: var(--purple-soft);  color: var(--purple); }
.ib-green  { background: var(--success-soft); color: var(--success); }
.ib-warn   { background: var(--warning-soft); color: var(--warning); }
.ib-danger { background: var(--danger-soft);  color: var(--danger); }

.stat-value {
    font-size: 1.9rem;
    font-weight: 700;
    letter-spacing: -0.02em;
    color: var(--text);
    line-height: 1.15;
    font-family: 'Inter', 'Pretendard Variable', sans-serif;
}

.stat-label {
    font-size: 0.8rem;
    color: var(--text-subtle);
    margin-top: 4px;
    font-weight: 500;
}

/* ── Buttons ───────────────────────────────────────────────────── */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    padding: 9px 18px;
    border: 1px solid transparent;
    border-radius: var(--r-sm);
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.15s ease;
    text-decoration: none;
    line-height: 1.4;
    letter-spacing: -0.01em;
    white-space: nowrap;
    font-family: inherit;
}

.btn:focus-visible { outline: none; box-shadow: var(--ring); }

.btn-primary { background: var(--primary); color: #fff; border-color: var(--primary); }
.btn-primary:hover { background: var(--primary-dark); border-color: var(--primary-dark); color: #fff; }

.btn-success { background: var(--success); color: #fff; border-color: var(--success); }
.btn-success:hover { background: #047857; border-color: #047857; color: #fff; }

.btn-danger { background: var(--danger); color: #fff; border-color: var(--danger); }
.btn-danger:hover { background: #B91C1C; border-color: #B91C1C; color: #fff; }

.btn-warning { background: var(--warning); color: #fff; border-color: var(--warning); }
.btn-warning:hover { background: #B45309; border-color: #B45309; color: #fff; }

.btn-outline {
    background: var(--surface);
    border: 1px solid var(--border-strong);
    color: var(--text);
}
.btn-outline:hover {
    background: var(--surface-alt);
    border-color: var(--primary);
    color: var(--primary);
}

.btn-sm { padding: 6px 12px; font-size: 0.82rem; }
.btn-lg { padding: 12px 24px; font-size: 1rem; }
.btn-block { width: 100%; }

/* ── Forms ─────────────────────────────────────────────────────── */
.form-group { margin-bottom: 16px; }

.form-label {
    display: block;
    font-weight: 600;
    margin-bottom: 6px;
    font-size: 0.85rem;
    color: var(--text);
    letter-spacing: -0.01em;
}

.form-control {
    width: 100%;
    padding: 10px 12px;
    border: 1px solid var(--border-strong);
    border-radius: var(--r-sm);
    font-size: 0.95rem;
    background: var(--surface);
    color: var(--text);
    font-family: inherit;
    transition: border-color 0.15s ease, box-shadow 0.15s ease;
}

.form-control:hover { border-color: var(--primary-line); }
.form-control:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: var(--ring);
}

.form-control::placeholder { color: var(--text-faint); }

select.form-control { appearance: auto; cursor: pointer; }

textarea.form-control { resize: vertical; min-height: 80px; }

/* ── Quiz Question ─────────────────────────────────────────────── */
.question-text {
    font-size: 1rem;
    line-height: 1.75;
    margin-bottom: 20px;
    padding: 18px 20px;
    background: var(--surface-alt);
    border-radius: var(--r-md);
    border-left: 3px solid var(--primary);
    color: var(--text);
}

.question-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    margin-bottom: 16px;
}

.question-meta .badge {
    padding: 3px 10px;
    border-radius: 999px;
    font-size: 0.72rem;
    font-weight: 600;
    letter-spacing: 0;
}

.option-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.option-item {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    padding: 14px 16px;
    border: 1px solid var(--border);
    border-radius: var(--r-md);
    background: var(--surface);
    cursor: pointer;
    transition: all 0.15s ease;
    position: relative;
}

.option-item:hover {
    border-color: var(--primary-line);
    background: var(--primary-soft);
}

.option-item.selected {
    border-color: var(--primary);
    background: var(--primary-soft);
    box-shadow: var(--ring);
}

.option-item.correct {
    border-color: var(--success);
    background: var(--success-soft);
}

.option-item.wrong {
    border-color: var(--danger);
    background: var(--danger-soft);
}

.option-letter {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 30px;
    height: 30px;
    border-radius: 50%;
    background: var(--surface-alt);
    border: 1px solid var(--border);
    font-weight: 700;
    font-size: 0.85rem;
    color: var(--text-muted);
    flex-shrink: 0;
    font-family: 'Inter', sans-serif;
}

.option-item.selected .option-letter {
    background: var(--primary);
    color: #fff;
    border-color: var(--primary);
}
.option-item.correct .option-letter {
    background: var(--success);
    color: #fff;
    border-color: var(--success);
}
.option-item.wrong .option-letter {
    background: var(--danger);
    color: #fff;
    border-color: var(--danger);
}

.option-text {
    flex: 1;
    padding-top: 3px;
    font-size: 0.95rem;
    line-height: 1.6;
    color: var(--text);
}

/* ── Translation Toggle ────────────────────────────────────────── */
.translation-wrapper { display: flex; gap: 16px; }
.translation-wrapper .original { flex: 1; }
.translation-wrapper .translation {
    flex: 1;
    background: var(--warning-soft);
    border-radius: var(--r-md);
    padding: 14px;
    display: none;
    border: 1px solid var(--warning-line);
    color: #78350F;
    line-height: 1.65;
}
.translation-wrapper .translation.show { display: block; }

.translation-toggle {
    background: var(--warning-soft);
    color: #92400E;
    border: 1px solid var(--warning-line);
    padding: 5px 12px;
    border-radius: 999px;
    font-size: 0.8rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.15s ease;
    font-family: inherit;
}
.translation-toggle:hover { background: var(--warning); color: #fff; border-color: var(--warning); }
.translation-toggle.active { background: var(--warning); color: #fff; border-color: var(--warning); }

/* ── Explanation ───────────────────────────────────────────────── */
.explanation-box {
    margin-top: 16px;
    padding: 18px;
    background: var(--success-soft);
    border: 1px solid var(--success-line);
    border-radius: var(--r-md);
    display: none;
    line-height: 1.7;
}
.explanation-box.show { display: block; }
.explanation-box h4 {
    color: var(--success);
    margin-bottom: 10px;
    font-size: 0.95rem;
    font-weight: 700;
}

/* ── Progress Bar ──────────────────────────────────────────────── */
.progress-bar-wrapper {
    width: 100%;
    height: 6px;
    background: var(--border);
    border-radius: 999px;
    overflow: hidden;
    margin-bottom: 16px;
}
.progress-bar {
    height: 100%;
    background: linear-gradient(90deg, var(--primary), var(--accent));
    border-radius: 999px;
    transition: width 0.3s ease;
}

/* ── Question Navigation ───────────────────────────────────────── */
.question-nav {
    display: none;
    flex-wrap: wrap;
    gap: 3px;
    margin: 6px 0 8px;
}
.question-nav .q-btn {
    width: 22px;
    height: 22px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    border: 1px solid var(--border);
    border-radius: var(--r-sm);
    font-size: 0.65rem;
    font-weight: 600;
    cursor: pointer;
    background: var(--surface);
    color: var(--text-muted);
    transition: all 0.15s ease;
    text-decoration: none;
    font-family: 'Inter', sans-serif;
}
.question-nav .q-btn:hover { border-color: var(--primary-line); color: var(--primary); }
.question-nav .q-btn.answered {
    background: var(--primary-soft);
    border-color: var(--primary-line);
    color: var(--primary);
}
.question-nav .q-btn.current {
    background: var(--primary);
    color: #fff;
    border-color: var(--primary);
}

/* ── Result Summary ────────────────────────────────────────────── */
.result-summary {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 32px;
    padding: 32px 24px;
    margin-bottom: 24px;
    border-radius: var(--r-lg);
    text-align: center;
    border: 1px solid var(--border);
    background: var(--surface);
}
.result-summary.pass {
    background: linear-gradient(135deg, var(--success-soft), #F0FDF4);
    border-color: var(--success-line);
}
.result-summary.fail {
    background: linear-gradient(135deg, var(--danger-soft), #FFF1F2);
    border-color: var(--danger-line);
}
.result-score {
    font-size: 2.75rem;
    font-weight: 800;
    letter-spacing: -0.03em;
    font-family: 'Inter', 'Pretendard Variable', sans-serif;
}
.result-detail {
    font-size: 0.9rem;
    color: var(--text-muted);
}

/* ── Badges ────────────────────────────────────────────────────── */
.badge {
    display: inline-block;
    padding: 3px 8px;
    border-radius: 999px;
    font-size: 0.72rem;
    font-weight: 600;
    letter-spacing: 0;
    line-height: 1.4;
}
.badge-primary { background: var(--primary-soft); color: var(--primary); }
.badge-success { background: var(--success-soft); color: var(--success); }
.badge-danger  { background: var(--danger-soft);  color: var(--danger);  }
.badge-warning { background: var(--warning-soft); color: var(--warning); }
.badge-info    { background: var(--info-soft);    color: var(--info);    }

/* ── Table ─────────────────────────────────────────────────────── */
.table-wrapper {
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    border-radius: var(--r-md);
    border: 1px solid var(--border);
}

table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.9rem;
}

th, td {
    padding: 11px 14px;
    text-align: left;
    border-bottom: 1px solid var(--border);
}

th {
    background: var(--surface-alt);
    font-weight: 600;
    color: var(--text-muted);
    font-size: 0.78rem;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    position: sticky;
    top: 0;
}

tbody tr:last-child td { border-bottom: none; }
tr:hover { background: var(--surface-alt); }

/* ── Flash Messages ────────────────────────────────────────────── */
.flash {
    padding: 12px 16px;
    border-radius: var(--r-md);
    margin-bottom: 16px;
    font-size: 0.9rem;
    display: flex;
    align-items: center;
    gap: 10px;
    border: 1px solid transparent;
}
.flash-success { background: var(--success-soft); color: #065F46; border-color: var(--success-line); }
.flash-error   { background: var(--danger-soft);  color: #991B1B; border-color: var(--danger-line); }
.flash-warning { background: var(--warning-soft); color: #92400E; border-color: var(--warning-line); }
.flash-info    { background: var(--info-soft);    color: #155E75; border-color: #A5F3FC; }

/* ── Login Page ────────────────────────────────────────────────── */
.login-container {
    max-width: 440px;
    margin: 80px auto;
    padding: 0 16px;
}

.login-card {
    background: var(--surface);
    border-radius: var(--r-lg);
    box-shadow: var(--shadow-md);
    padding: 40px 32px;
    text-align: center;
    border: 1px solid var(--border);
}
.login-card h1 {
    font-size: 1.4rem;
    margin-bottom: 8px;
    background: linear-gradient(135deg, var(--primary), var(--accent));
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    color: transparent;
}
.login-card p { color: var(--text-muted); margin-bottom: 24px; font-size: 0.9rem; }

/* ── Footer ────────────────────────────────────────────────────── */
.footer {
    text-align: center;
    padding: 28px 16px;
    color: var(--text-subtle);
    font-size: 0.8rem;
    margin-top: 48px;
    border-top: 1px solid var(--border);
    background: var(--surface);
}
.footer p { margin: 2px 0; }
.footer a { color: var(--primary); text-decoration: none; font-weight: 500; }
.footer a:hover { text-decoration: underline; }

/* ── Tabs ──────────────────────────────────────────────────────── */
.tabs {
    display: flex;
    gap: 0;
    border-bottom: 1px solid var(--border);
    margin-bottom: 22px;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
}
.tab {
    padding: 11px 18px;
    cursor: pointer;
    border: none;
    background: none;
    font-size: 0.88rem;
    font-weight: 600;
    color: var(--text-subtle);
    border-bottom: 2px solid transparent;
    margin-bottom: -1px;
    white-space: nowrap;
    transition: all 0.15s ease;
    font-family: inherit;
    letter-spacing: -0.01em;
}
.tab:hover { color: var(--text); }
.tab.active {
    color: var(--primary);
    border-bottom-color: var(--primary);
}
.tab-content { display: none; }
.tab-content.active { display: block; }

/* ── Answer Count Hint ─────────────────────────────────────────── */
.answer-count-hint {
    display: inline-block;
    padding: 4px 12px;
    background: var(--info-soft);
    color: var(--info);
    border: 1px solid #A5F3FC;
    border-radius: 999px;
    font-size: 0.78rem;
    font-weight: 600;
    margin-bottom: 12px;
}

/* ── Slicer Card / Chips (quiz_start.html) ─────────────────────── */
.slicer-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--r-lg);
    margin-bottom: 14px;
    overflow: hidden;
    box-shadow: var(--shadow-xs);
    transition: border-color 0.15s ease, box-shadow 0.15s ease;
}
.slicer-card:hover { border-color: var(--primary-line); box-shadow: var(--shadow-sm); }

.sc-header {
    padding: 14px 18px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    cursor: pointer;
    user-select: none;
    transition: background 0.15s ease;
}
.sc-header:hover { background: var(--surface-alt); }

.sc-title {
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 700;
    color: var(--text);
    font-size: 0.95rem;
    letter-spacing: -0.01em;
}
.sc-icon { font-size: 1.05rem; }
.sc-subtitle {
    font-size: 0.78rem;
    color: var(--text-subtle);
    font-weight: 500;
    margin-left: 4px;
}
.sc-badge {
    background: var(--primary-soft);
    color: var(--primary);
    border-radius: 999px;
    padding: 2px 9px;
    font-size: 0.72rem;
    font-weight: 700;
    margin-left: 6px;
}
.sc-badge:empty { display: none; }
.sc-arrow {
    color: var(--text-faint);
    font-size: 0.85rem;
    transition: transform 0.2s ease;
}
.slicer-card.collapsed .sc-arrow { transform: rotate(-90deg); }

.sc-body {
    padding: 4px 18px 18px;
    border-top: 1px solid var(--border);
}

.sc-level { padding: 10px 0; }
.sc-level + .sc-level { border-top: 1px dashed var(--border); }

.sc-level-label {
    display: inline-block;
    font-size: 0.75rem;
    font-weight: 700;
    color: var(--text-subtle);
    text-transform: uppercase;
    letter-spacing: 0.04em;
    margin-bottom: 8px;
}
.child-label { color: var(--primary); font-weight: 600; text-transform: none; }

.chip-row {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
}

.slicer-chip {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 5px 12px;
    border: 1px solid var(--border-strong);
    border-radius: 999px;
    background: var(--surface);
    color: var(--text-muted);
    font-size: 0.8rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.15s ease;
    user-select: none;
    white-space: nowrap;
}
.slicer-chip:hover {
    border-color: var(--primary);
    color: var(--primary);
    background: var(--primary-soft);
}
.slicer-chip.active,
.slicer-chip.selected {
    background: var(--primary);
    border-color: var(--primary);
    color: #fff;
}
.parent-chip { font-weight: 600; }
.task-chip { font-size: 0.76rem; padding: 4px 10px; }
.flat-chip { font-weight: 500; }
.slicer-chip.parent-chip.selected,
.slicer-chip.parent-chip.active {
    background: var(--primary-dark);
    border-color: var(--primary-dark);
}

.start-panel {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--r-lg);
    padding: 20px;
    margin-top: 20px;
    box-shadow: var(--shadow-xs);
}

/* ── Responsive ────────────────────────────────────────────────── */
@media (max-width: 768px) {
    html, body { font-size: 14.5px; }

    .hamburger { display: block; }

    .navbar-nav {
        display: none;
        position: absolute;
        top: 60px;
        left: 0;
        right: 0;
        background: var(--surface);
        backdrop-filter: none;
        flex-direction: column;
        padding: 10px;
        gap: 2px;
        box-shadow: var(--shadow-lg);
        border-bottom: 1px solid var(--border);
    }
    .navbar-nav.open { display: flex; }
    .navbar-nav a {
        padding: 12px 14px;
        width: 100%;
        border-radius: var(--r-sm);
    }

    .main-content { padding: 18px 14px 32px; }

    .card { padding: 18px; }

    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 10px;
    }
    .stat-card { padding: 16px; }
    .stat-value { font-size: 1.45rem; }

    .translation-wrapper { flex-direction: column; }

    .result-summary {
        flex-direction: column;
        gap: 10px;
        padding: 24px 16px;
    }
    .result-score { font-size: 2rem; }

    .question-nav .q-btn {
        width: 18px;
        height: 18px;
        font-size: 0.55rem;
    }

    .option-item { padding: 12px 14px; }
    .option-letter { width: 28px; height: 28px; font-size: 0.8rem; }

    table { font-size: 0.82rem; }
    th, td { padding: 9px 10px; }

    .btn { padding: 8px 14px; font-size: 0.88rem; }

    .pc-only { display: none !important; }
    .pc-only-notice {
        display: block;
        text-align: center;
        padding: 12px;
        background: var(--warning-soft);
        color: #92400E;
        border: 1px solid var(--warning-line);
        border-radius: var(--r-sm);
        font-size: 0.85rem;
    }
}

@media (min-width: 769px) {
    .pc-only-notice { display: none; }
    .mobile-only { display: none !important; }
}

/* ── Chart Container ───────────────────────────────────────────── */
.chart-container {
    position: relative;
    width: 100%;
    max-height: 320px;
    padding: 4px 0;
}

/* ── Loading Spinner ───────────────────────────────────────────── */
.spinner {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 2px solid var(--border);
    border-top-color: var(--primary);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* ── Admin Actions ─────────────────────────────────────────────── */
.admin-actions { display: flex; gap: 6px; flex-wrap: wrap; }

/* ── Empty State ───────────────────────────────────────────────── */
.empty-state {
    text-align: center;
    padding: 44px 20px;
    color: var(--text-subtle);
}
.empty-state .icon {
    font-size: 2.6rem;
    margin-bottom: 12px;
    color: var(--text-faint);
}

/* ── Bookmark / Report Buttons ─────────────────────────────────── */
.question-actions {
    display: flex;
    gap: 8px;
    justify-content: flex-end;
    margin-top: 12px;
    flex-wrap: wrap;
}

.btn-bookmark, .btn-report {
    background: var(--surface);
    border: 1px solid var(--border);
    color: var(--text-muted);
    border-radius: var(--r-sm);
    padding: 5px 12px;
    cursor: pointer;
    font-size: 0.82rem;
    font-weight: 500;
    display: inline-flex;
    align-items: center;
    gap: 5px;
    transition: all 0.15s ease;
    font-family: inherit;
}

.btn-bookmark:hover { border-color: var(--warning); color: var(--warning); background: var(--warning-soft); }
.btn-bookmark.active { border-color: var(--warning); color: var(--warning); background: var(--warning-soft); }
.btn-bookmark.active .fa-bookmark { font-weight: 900; }

.btn-report:hover { border-color: var(--danger); color: var(--danger); background: var(--danger-soft); }

/* ── Report Modal ──────────────────────────────────────────────── */
.modal-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(16, 24, 40, 0.55);
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
    z-index: 1000;
    align-items: center;
    justify-content: center;
    padding: 16px;
}
.modal-overlay.show { display: flex; }
.modal-box {
    background: var(--surface);
    border-radius: var(--r-lg);
    padding: 24px;
    max-width: 440px;
    width: 100%;
    box-shadow: var(--shadow-xl);
    border: 1px solid var(--border);
}
.modal-box h3 { margin-bottom: 16px; font-size: 1.05rem; color: var(--text); }
.modal-box label {
    display: block;
    margin-bottom: 8px;
    cursor: pointer;
    font-size: 0.9rem;
    color: var(--text-muted);
}
.modal-box label input[type=radio] { margin-right: 8px; accent-color: var(--primary); }
.modal-box textarea {
    width: 100%;
    margin-top: 10px;
    padding: 10px;
    border: 1px solid var(--border-strong);
    border-radius: var(--r-sm);
    font-size: 0.9rem;
    font-family: inherit;
    resize: vertical;
    min-height: 80px;
    background: var(--surface);
    color: var(--text);
}
.modal-box textarea:focus { outline: none; border-color: var(--primary); box-shadow: var(--ring); }
.modal-actions { display: flex; gap: 8px; justify-content: flex-end; margin-top: 16px; }

/* ── Bookmarks Page ────────────────────────────────────────────── */
.bookmark-item {
    border: 1px solid var(--border);
    border-radius: var(--r-lg);
    padding: 18px;
    margin-bottom: 12px;
    background: var(--surface);
    transition: border-color 0.15s ease, box-shadow 0.15s ease;
}
.bookmark-item:hover {
    border-color: var(--primary-line);
    box-shadow: var(--shadow-sm);
}
.bookmark-item .q-no {
    color: var(--text-subtle);
    font-size: 0.78rem;
    font-weight: 600;
    margin-bottom: 8px;
}
.bookmark-item .q-text {
    font-size: 0.95rem;
    line-height: 1.6;
    color: var(--text);
}
.bookmark-item .answer-badge {
    display: inline-block;
    background: var(--success);
    color: #fff;
    border-radius: 999px;
    padding: 3px 10px;
    font-size: 0.78rem;
    font-weight: 600;
    margin-top: 10px;
}

/* ── Copy-protection helper (Exam 보안) ────────────────────────── */
.secure-text {
    user-select: none;
    -webkit-user-select: none;
    -moz-user-select: none;
}

/* ══════════════════════════════════════════════════════════════════
   DARK MODE
   ══════════════════════════════════════════════════════════════════ */
html.dark-preload body, body.dark {
    --bg:            #0B1220;
    --surface:       #111A2C;
    --card-bg:       #111A2C;
    --surface-alt:   #161F33;
    --border:        #1F2A44;
    --border-strong: #2A3854;
    --text:          #E5EAF4;
    --text-muted:    #A3AEC2;
    --text-subtle:   #8893AC;
    --text-faint:    #64718A;

    --primary-soft:  #1A2442;
    --primary-line:  #2F3F70;

    --success-soft:  #0F2A21;
    --success-line:  #1F4A3A;
    --danger-soft:   #2A1414;
    --danger-line:   #4A2323;
    --warning-soft:  #2A2010;
    --warning-line:  #4A3A1F;
    --info-soft:     #0F2A30;

    --shadow-xs: 0 1px 2px rgba(0,0,0,.35);
    --shadow-sm: 0 1px 3px rgba(0,0,0,.40), 0 1px 2px rgba(0,0,0,.30);
    --shadow-md: 0 4px 12px rgba(0,0,0,.45);
    --shadow-lg: 0 12px 24px rgba(0,0,0,.55);
    --shadow-xl: 0 24px 48px rgba(0,0,0,.65);
}

body.dark { background: var(--bg); color: var(--text); }

body.dark .navbar {
    background: rgba(11, 18, 32, 0.82);
    border-bottom-color: var(--border);
}
body.dark .navbar-brand { color: var(--text); }

body.dark .card,
body.dark .stat-card,
body.dark .slicer-card,
body.dark .start-panel,
body.dark .login-card,
body.dark .bookmark-item {
    background: var(--surface);
    border-color: var(--border);
}

body.dark .form-control,
body.dark input, body.dark select, body.dark textarea {
    background: #0F1626;
    color: var(--text);
    border-color: var(--border-strong);
}

body.dark .question-text { background: var(--surface-alt); color: var(--text); }

body.dark .option-item {
    border-color: var(--border);
    background: var(--surface);
}
body.dark .option-item:hover { background: var(--surface-alt); border-color: var(--primary-line); }
body.dark .option-item.selected { background: var(--primary-soft); border-color: var(--primary); }
body.dark .option-item.correct  { background: var(--success-soft); border-color: var(--success); }
body.dark .option-item.wrong    { background: var(--danger-soft);  border-color: var(--danger);  }

body.dark .option-letter {
    background: var(--surface-alt);
    border-color: var(--border);
    color: var(--text-muted);
}

body.dark .explanation-box { background: var(--success-soft); border-color: var(--success-line); color: var(--text); }
body.dark .explanation-box h4 { color: #6EE7B7; }

body.dark .translation-wrapper .translation {
    background: var(--warning-soft);
    border-color: var(--warning-line);
    color: #FDE68A;
}
body.dark .translation-toggle { background: var(--warning-soft); color: #FDE68A; border-color: var(--warning-line); }
body.dark .translation-toggle:hover,
body.dark .translation-toggle.active { background: var(--warning); color: #fff; }

body.dark .flash-success { background: var(--success-soft); color: #86EFAC; border-color: var(--success-line); }
body.dark .flash-error   { background: var(--danger-soft);  color: #FCA5A5; border-color: var(--danger-line); }
body.dark .flash-warning { background: var(--warning-soft); color: #FCD34D; border-color: var(--warning-line); }
body.dark .flash-info    { background: var(--info-soft);    color: #67E8F9; border-color: #155E75; }

body.dark .badge-primary { background: var(--primary-soft); color: #93C5FD; }
body.dark .badge-success { background: var(--success-soft); color: #86EFAC; }
body.dark .badge-danger  { background: var(--danger-soft);  color: #FCA5A5; }
body.dark .badge-warning { background: var(--warning-soft); color: #FCD34D; }
body.dark .badge-info    { background: var(--info-soft);    color: #67E8F9; }

body.dark .table-wrapper { border-color: var(--border); }
body.dark table { color: var(--text); }
body.dark th {
    background: var(--surface-alt) !important;
    color: var(--text-muted) !important;
    border-color: var(--border) !important;
}
body.dark td { border-color: var(--border) !important; }
body.dark tr:hover { background: var(--surface-alt); }

body.dark .tabs { border-bottom-color: var(--border); }

body.dark .navbar-nav a { color: var(--text-muted); }
body.dark .navbar-nav a:hover { background: var(--surface-alt); color: var(--text); }
body.dark .navbar-nav a.active { background: var(--primary-soft); color: #93C5FD; }
body.dark .navbar-nav a.active i { color: #93C5FD; }

body.dark .dark-toggle {
    background: var(--surface-alt);
    color: var(--text-muted);
    border-color: var(--border);
}
body.dark .dark-toggle:hover { color: var(--text); background: var(--surface); }

body.dark .slicer-chip {
    background: var(--surface-alt);
    color: var(--text-muted);
    border-color: var(--border-strong);
}
body.dark .slicer-chip:hover { color: #93C5FD; background: var(--primary-soft); border-color: var(--primary); }
body.dark .slicer-chip.active,
body.dark .slicer-chip.selected { background: var(--primary); color: #fff; border-color: var(--primary); }

body.dark .answer-count-hint {
    background: var(--info-soft);
    color: #67E8F9;
    border-color: #155E75;
}

body.dark .sc-badge { background: var(--primary-soft); color: #93C5FD; }

body.dark .footer {
    background: var(--surface);
    border-top-color: var(--border);
    color: var(--text-subtle);
}

body.dark .question-nav .q-btn {
    background: var(--surface);
    color: var(--text-muted);
    border-color: var(--border);
}
body.dark .question-nav .q-btn:hover { color: #93C5FD; border-color: var(--primary-line); }
body.dark .question-nav .q-btn.answered {
    background: var(--primary-soft);
    color: #93C5FD;
    border-color: var(--primary-line);
}
body.dark .question-nav .q-btn.current {
    background: var(--primary);
    color: #fff;
    border-color: var(--primary);
}

body.dark .result-summary.pass { background: linear-gradient(135deg, var(--success-soft), #0A1F18); }
body.dark .result-summary.fail { background: linear-gradient(135deg, var(--danger-soft),  #1F0E0E); }

body.dark .btn-outline {
    background: var(--surface);
    border-color: var(--border-strong);
    color: var(--text);
}
body.dark .btn-outline:hover { background: var(--surface-alt); color: #93C5FD; border-color: var(--primary); }

body.dark .login-card h1 {
    background: linear-gradient(135deg, #93C5FD, #60A5FA);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

body.dark .btn-bookmark, body.dark .btn-report {
    background: var(--surface);
    border-color: var(--border);
    color: var(--text-muted);
}

body.dark .modal-overlay { background: rgba(0, 0, 0, 0.65); }
body.dark .modal-box { background: var(--surface); border-color: var(--border); }

body.dark ::selection { background: var(--primary-soft); color: #93C5FD; }