/* ====================================================================
   AI Education Service – Light Modern AI Design System
   Inspired by OpenAI Platform & Hugging Face
   Clean white, warm accents, smooth animations, wide PC layout
   ==================================================================== */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800;900&family=Noto+Sans+KR:wght@300;400;500;600;700;800;900&display=swap');

:root {
    /* === Backgrounds === */
    --bg-body: #ffffff;
    --bg-surface: #f8fafc;
    --bg-card: #ffffff;
    --bg-elevated: #f1f5f9;
    --bg-hover: #f8fafc;
    --bg-muted: #f0f4f8;
    /* === Borders === */
    --border: #e2e8f0;
    --border-light: #f1f5f9;
    --border-focus: #6366f1;
    /* === Text === */
    --text: #0f172a;
    --text-secondary: #475569;
    --text-muted: #94a3b8;
    --text-dim: #cbd5e1;
    /* === Primary (Indigo–Violet) === */
    --primary: #6366f1;
    --primary-hover: #4f46e5;
    --primary-light: #eef2ff;
    --primary-lighter: #f5f3ff;
    --primary-glow: rgba(99, 102, 241, 0.15);
    /* === Secondary (Cyan–Teal) === */
    --secondary: #06b6d4;
    --secondary-light: #ecfeff;
    --secondary-glow: rgba(6, 182, 212, 0.12);
    /* === Accent (Yellow–Amber, HF-inspired) === */
    --accent: #f59e0b;
    --accent-hover: #d97706;
    --accent-light: #fffbeb;
    --accent-glow: rgba(245, 158, 11, 0.12);
    /* === Purple === */
    --purple: #8b5cf6;
    --purple-light: #f5f3ff;
    --purple-glow: rgba(139, 92, 246, 0.12);
    /* === Semantic === */
    --success: #10b981;
    --success-light: #ecfdf5;
    --warning: #f59e0b;
    --warning-light: #fffbeb;
    --danger: #ef4444;
    --danger-light: #fef2f2;
    /* === Gradients === */
    --grad-primary: linear-gradient(135deg, #6366f1, #8b5cf6);
    --grad-warm: linear-gradient(135deg, #f59e0b, #ef4444);
    --grad-cool: linear-gradient(135deg, #06b6d4, #6366f1);
    --grad-fresh: linear-gradient(135deg, #10b981, #06b6d4);
    --grad-sunset: linear-gradient(135deg, #f59e0b, #ec4899);
    --grad-hero: linear-gradient(135deg, #eef2ff 0%, #f5f3ff 30%, #ecfeff 70%, #ffffff 100%);
    --grad-subtle: linear-gradient(135deg, rgba(99,102,241,0.04), rgba(6,182,212,0.02));
    /* === Shadows === */
    --shadow-xs: 0 1px 2px rgba(0,0,0,0.04);
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
    --shadow: 0 4px 6px -1px rgba(0,0,0,0.07), 0 2px 4px -1px rgba(0,0,0,0.04);
    --shadow-md: 0 10px 25px -3px rgba(0,0,0,0.08), 0 4px 6px -2px rgba(0,0,0,0.04);
    --shadow-lg: 0 20px 40px -8px rgba(0,0,0,0.1);
    --shadow-glow: 0 4px 20px rgba(99,102,241,0.12);
    --shadow-glow-warm: 0 4px 20px rgba(245,158,11,0.12);
    /* === Dimensions === */
    --radius: 10px;
    --radius-lg: 16px;
    --radius-xl: 20px;
    --radius-2xl: 28px;
    --radius-full: 9999px;
    --max-width: 1400px;
    /* === Typography === */
    --font: 'Inter', 'Noto Sans KR', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --transition: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

/* === Reset === */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
    font-family: var(--font);
    background: var(--bg-body);
    color: var(--text);
    min-height: 100vh;
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
}
a { color: var(--primary); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--primary-hover); }

/* =======================================================
   ANIMATED BACKGROUND – Soft floating orbs on white
   ======================================================= */
.bg-mesh {
    position: fixed; top: 0; left: 0; right: 0; bottom: 0;
    z-index: 0; pointer-events: none; overflow: hidden;
}
.bg-mesh::before {
    content: ''; position: absolute; width: 800px; height: 800px;
    top: -250px; left: -200px;
    background: radial-gradient(circle, rgba(99,102,241,0.06) 0%, transparent 70%);
    border-radius: 50%;
    animation: meshFloat1 25s ease-in-out infinite;
}
.bg-mesh::after {
    content: ''; position: absolute; width: 600px; height: 600px;
    bottom: -100px; right: -100px;
    background: radial-gradient(circle, rgba(245,158,11,0.05) 0%, transparent 70%);
    border-radius: 50%;
    animation: meshFloat2 30s ease-in-out infinite;
}
@keyframes meshFloat1 {
    0%,100% { transform: translate(0,0) scale(1); }
    33% { transform: translate(100px,50px) scale(1.08); }
    66% { transform: translate(-50px,100px) scale(0.95); }
}
@keyframes meshFloat2 {
    0%,100% { transform: translate(0,0) scale(1); }
    50% { transform: translate(-80px,-60px) scale(1.12); }
}
.bg-grid {
    position: fixed; top: 0; left: 0; right: 0; bottom: 0;
    z-index: 0; pointer-events: none;
    background-image:
        linear-gradient(rgba(99,102,241,0.025) 1px, transparent 1px),
        linear-gradient(90deg, rgba(99,102,241,0.025) 1px, transparent 1px);
    background-size: 64px 64px;
}

/* =======================================================
   ANIMATIONS
   ======================================================= */
@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(20px); }
    to   { opacity: 1; transform: translateY(0); }
}
@keyframes fadeIn {
    from { opacity: 0; }
    to   { opacity: 1; }
}
@keyframes slideInRight {
    from { opacity: 0; transform: translateX(20px); }
    to   { opacity: 1; transform: translateX(0); }
}
@keyframes float {
    0%,100% { transform: translateY(0); }
    50% { transform: translateY(-6px); }
}
@keyframes pulse {
    0%,100% { opacity: 1; }
    50% { opacity: 0.6; }
}
@keyframes shimmer {
    0% { background-position: -200% 0; }
    100% { background-position: 200% 0; }
}
@keyframes spin {
    to { transform: rotate(360deg); }
}
@keyframes gradientShift {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}
@keyframes scaleIn {
    from { opacity: 0; transform: scale(0.95); }
    to   { opacity: 1; transform: scale(1); }
}
@keyframes borderGlow {
    0%,100% { border-color: var(--border); }
    50% { border-color: rgba(99,102,241,0.3); }
}
@keyframes dotPulse {
    0%,100% { transform: scale(1); opacity: 0.7; }
    50% { transform: scale(1.5); opacity: 1; }
}

.anim-in { animation: fadeInUp 0.5s ease both; }
.anim-delay-1 { animation-delay: 0.06s; opacity: 0; }
.anim-delay-2 { animation-delay: 0.12s; opacity: 0; }
.anim-delay-3 { animation-delay: 0.18s; opacity: 0; }
.anim-delay-4 { animation-delay: 0.24s; opacity: 0; }
.anim-delay-5 { animation-delay: 0.30s; opacity: 0; }

/* =======================================================
   PAGE WRAPPER
   ======================================================= */
.page-wrapper {
    position: relative; z-index: 1;
    min-height: 100vh; display: flex; flex-direction: column;
}

/* =======================================================
   TOPBAR – Slim utility bar
   ======================================================= */
.topbar {
    background: var(--bg-surface);
    border-bottom: 1px solid var(--border);
    padding: 6px 0; font-size: 13px;
}
.topbar-inner {
    max-width: var(--max-width); margin: 0 auto; padding: 0 40px;
    display: flex; align-items: center; justify-content: space-between;
}
.topbar-org { font-weight: 600; color: var(--text-secondary); white-space: nowrap; }
.topbar-links { display: flex; align-items: center; gap: 20px; flex-shrink: 0; flex-wrap: nowrap; }
.topbar-links a { color: var(--text-muted); font-size: 13px; font-weight: 500; white-space: nowrap; flex-shrink: 0; }
.topbar-links a:hover { color: var(--primary); }
.topbar-links .lang-select {
    flex-shrink: 0;
    height: 24px;
    padding: 0 22px 0 8px;
    font-size: 12px; font-weight: 600; line-height: 1;
    color: var(--text-secondary);
    background-color: var(--bg-surface);
    border: 1px solid var(--border); border-radius: 6px;
    cursor: pointer; appearance: none; -webkit-appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='10' height='6' viewBox='0 0 10 6'%3E%3Cpath fill='%23666' d='M0 0l5 6 5-6z'/%3E%3C/svg%3E");
    background-repeat: no-repeat; background-position: right 6px center;
}
.topbar-links .lang-select:hover { color: var(--primary); border-color: var(--primary); }
.topbar-links .lang-select:focus { outline: none; border-color: var(--primary); box-shadow: 0 0 0 2px rgba(99,102,241,.15); }
.topbar-inner { gap: 16px; }
.topbar-inner .topbar-org { min-width: 0; overflow: hidden; text-overflow: ellipsis; }

/* =======================================================
   NAVBAR – Clean, white, sticky
   ======================================================= */
.navbar {
    position: sticky; top: 0; z-index: 300;
    background: rgba(255,255,255,0.92);
    backdrop-filter: blur(16px); -webkit-backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--border);
    box-shadow: 0 1px 3px rgba(0,0,0,0.04);
}
.navbar-inner {
    max-width: var(--max-width); margin: 0 auto; padding: 0 40px;
    height: 60px; display: flex; align-items: center; justify-content: space-between;
}
.logo {
    display: flex; align-items: center; gap: 10px;
    text-decoration: none; color: var(--text); font-weight: 800; font-size: 17px;
}
.logo-icon {
    width: 36px; height: 36px; border-radius: 10px;
    background: var(--grad-primary); display: flex; align-items: center; justify-content: center;
    font-size: 13px; font-weight: 900; color: #fff;
    box-shadow: 0 2px 8px rgba(99,102,241,0.25);
}
.nav-links { display: flex; align-items: center; gap: 2px; }
.nav-links a {
    padding: 7px 14px; color: var(--text-secondary); font-size: 14px; font-weight: 500;
    border-radius: 8px; transition: all var(--transition); position: relative;
}
.nav-links a:hover { color: var(--text); background: var(--bg-surface); }
.nav-links a.active {
    color: var(--primary); font-weight: 600; background: var(--primary-light);
}
.nav-links a.active::after {
    content: ''; position: absolute; bottom: -1px; left: 50%; transform: translateX(-50%);
    width: 18px; height: 2px; background: var(--primary); border-radius: 2px;
}
.nav-btn {
    margin-left: 10px; padding: 7px 18px;
    background: var(--grad-primary); color: #fff;
    border: none; border-radius: 8px; font-size: 13px; font-weight: 600; font-family: var(--font);
    cursor: pointer; transition: all var(--transition);
    box-shadow: 0 2px 8px rgba(99,102,241,0.2);
}
.nav-btn:hover { transform: translateY(-1px); box-shadow: 0 4px 16px rgba(99,102,241,0.3); }

/* =======================================================
   MAIN CONTENT
   ======================================================= */
.main-content {
    flex: 1; max-width: var(--max-width); margin: 0 auto;
    padding: 36px 40px 60px; width: 100%;
}

/* =======================================================
   BUTTONS
   ======================================================= */
.btn {
    display: inline-flex; align-items: center; justify-content: center; gap: 8px;
    padding: 10px 22px; border: none; border-radius: 8px;
    font-size: 14px; font-weight: 600; font-family: var(--font); cursor: pointer;
    transition: all var(--transition); text-decoration: none; line-height: 1.4; white-space: nowrap;
}
.btn-primary {
    background: var(--grad-primary); color: #fff;
    box-shadow: 0 2px 10px rgba(99,102,241,0.2);
}
.btn-primary:hover {
    transform: translateY(-1px); box-shadow: 0 6px 20px rgba(99,102,241,0.3);
    color: #fff;
}
.btn-secondary {
    background: var(--bg-surface); color: var(--text-secondary);
    border: 1px solid var(--border);
}
.btn-secondary:hover {
    border-color: var(--primary); color: var(--primary); background: var(--primary-light);
}
.btn-ghost { background: transparent; color: var(--primary); }
.btn-ghost:hover { background: var(--primary-light); }
.btn-accent {
    background: linear-gradient(135deg, #f59e0b, #f97316); color: #fff;
    box-shadow: 0 2px 10px rgba(245,158,11,0.2);
}
.btn-accent:hover { transform: translateY(-1px); box-shadow: 0 6px 20px rgba(245,158,11,0.3); color: #fff; }
.btn-danger { background: var(--danger); color: #fff; }
.btn-danger:hover { background: #dc2626; color: #fff; }
.btn-success { background: var(--success); color: #fff; }
.btn-sm { padding: 7px 14px; font-size: 13px; }
.btn-lg { padding: 14px 32px; font-size: 15px; }
.btn-full { width: 100%; }
.btn-outline-primary {
    background: transparent; color: var(--primary); border: 1.5px solid var(--primary);
}
.btn-outline-primary:hover {
    background: var(--primary-light); color: var(--primary);
}

/* =======================================================
   INPUTS
   ======================================================= */
.input, input[type="text"], input[type="password"], input[type="email"], textarea, select {
    width: 100%; padding: 12px 16px;
    border: 1.5px solid var(--border); border-radius: var(--radius);
    font-size: 15px; font-family: var(--font);
    background: #fff; color: var(--text);
    transition: all var(--transition);
}
.input:focus, input:focus, textarea:focus, select:focus {
    outline: none; border-color: var(--primary);
    box-shadow: 0 0 0 3px var(--primary-glow);
}
.input::placeholder, input::placeholder { color: var(--text-dim); }

/* =======================================================
   CARDS – Clean elevated cards
   ======================================================= */
.glass-card {
    background: var(--bg-card);
    border: 1px solid var(--border); border-radius: var(--radius-xl);
    padding: 28px; box-shadow: var(--shadow-sm);
    transition: all var(--transition); position: relative; overflow: hidden;
}
.glass-card:hover {
    box-shadow: var(--shadow-md);
    border-color: rgba(99,102,241,0.15);
}
.glass-card h2 { font-size: 20px; font-weight: 700; letter-spacing: -0.02em; }
/* Accent top-line on cards */
.glass-card.card-accent::before {
    content: ''; position: absolute; top: 0; left: 0; right: 0; height: 3px;
    background: var(--grad-primary); border-radius: 3px 3px 0 0;
}

/* =======================================================
   BADGES
   ======================================================= */
.badge {
    display: inline-flex; align-items: center; gap: 4px;
    padding: 3px 10px; border-radius: var(--radius-full);
    font-size: 12px; font-weight: 600;
}
.badge-blue { background: var(--primary-light); color: var(--primary); }
.badge-cyan { background: var(--secondary-light); color: var(--secondary); }
.badge-purple { background: var(--purple-light); color: var(--purple); }
.badge-success { background: var(--success-light); color: var(--success); }
.badge-warning { background: var(--warning-light); color: var(--accent); }
.badge-danger { background: var(--danger-light); color: var(--danger); }
.badge-glow {
    background: linear-gradient(135deg, #ef4444, #ec4899); color: #fff;
    box-shadow: 0 2px 8px rgba(239,68,68,0.25);
}
.badge-primary {
    background: var(--grad-primary); color: #fff;
    box-shadow: 0 2px 6px rgba(99,102,241,0.2);
}

/* =======================================================
   PROGRESS BAR
   ======================================================= */
.progress-bar {
    width: 100%; height: 8px;
    background: var(--bg-elevated); border-radius: var(--radius-full); overflow: hidden;
}
.progress-fill {
    height: 100%; border-radius: var(--radius-full);
    background: var(--grad-primary);
    transition: width 0.8s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
}
.progress-fill::after {
    content: ''; position: absolute; top: 0; left: 0; right: 0; bottom: 0;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.4), transparent);
    animation: shimmer 2s infinite; background-size: 200% 100%;
}
.progress-bar-lg { height: 10px; }

/* =======================================================
   STATS GRID
   ======================================================= */
.stats-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; margin-bottom: 28px; }
@media (max-width: 1024px) { .stats-grid { grid-template-columns: repeat(2, 1fr); } }

.stat-card {
    background: var(--bg-card); border: 1px solid var(--border);
    border-radius: var(--radius-lg); padding: 24px; text-align: center;
    transition: all var(--transition); position: relative; overflow: hidden;
}
.stat-card::before {
    content: ''; position: absolute; top: 0; left: 0; right: 0; height: 3px;
    border-radius: 3px 3px 0 0;
}
.stat-card:hover {
    transform: translateY(-3px); box-shadow: var(--shadow-md);
    border-color: rgba(99,102,241,0.15);
}
.stat-card-blue::before { background: var(--grad-primary); }
.stat-card-cyan::before { background: var(--grad-cool); }
.stat-card-purple::before { background: linear-gradient(135deg, #8b5cf6, #a855f7); }
.stat-card-pink::before { background: var(--grad-sunset); }
.stat-card-warm::before { background: var(--grad-warm); }
.stat-icon {
    width: 48px; height: 48px; border-radius: 12px;
    display: flex; align-items: center; justify-content: center;
    margin: 0 auto 12px; font-size: 22px;
}
.stat-card-blue .stat-icon { background: var(--primary-light); }
.stat-card-cyan .stat-icon { background: var(--secondary-light); }
.stat-card-purple .stat-icon { background: var(--purple-light); }
.stat-card-pink .stat-icon { background: #fdf2f8; }
.stat-card-warm .stat-icon { background: var(--accent-light); }
.stat-value { font-size: 30px; font-weight: 800; letter-spacing: -0.03em; color: var(--text); }
.stat-label { font-size: 13px; color: var(--text-muted); margin-top: 4px; font-weight: 500; }

/* =======================================================
   TABLES
   ======================================================= */
.table-wrap {
    overflow-x: auto; border-radius: var(--radius-lg);
    border: 1px solid var(--border); background: var(--bg-card);
}
table { width: 100%; border-collapse: collapse; }
th, td { padding: 14px 20px; text-align: left; border-bottom: 1px solid var(--border-light); }
th {
    font-weight: 600; color: var(--text-muted); font-size: 12px;
    text-transform: uppercase; letter-spacing: 0.05em; background: var(--bg-surface);
}
td { font-size: 14px; color: var(--text-secondary); }
tr:last-child td { border-bottom: none; }
tr:hover td { background: var(--primary-lighter); }

/* =======================================================
   SECTION HEADERS
   ======================================================= */
.section-header {
    display: flex; align-items: center; justify-content: space-between;
    margin: 32px 0 18px; padding-bottom: 14px; border-bottom: 1px solid var(--border);
}
.section-header h3 { font-size: 17px; font-weight: 700; display: flex; align-items: center; gap: 10px; }
.section-icon {
    width: 34px; height: 34px; border-radius: 10px;
    display: inline-flex; align-items: center; justify-content: center; font-size: 15px;
}
.section-more {
    font-size: 13px; font-weight: 600; color: var(--primary);
    display: flex; align-items: center; gap: 4px;
}
.section-more:hover { color: var(--primary-hover); }

/* =======================================================
   PAGE HERO – Gradient top banner
   ======================================================= */
.page-hero {
    padding: 32px 36px; background: var(--grad-hero);
    border: 1px solid var(--border); border-radius: var(--radius-xl);
    margin-bottom: 28px; position: relative; overflow: hidden;
}
.page-hero::before {
    content: ''; position: absolute; top: 0; left: 0; right: 0; height: 3px;
    background: var(--grad-primary);
}
.page-hero h1 {
    font-size: 26px; font-weight: 800; margin-bottom: 6px;
    letter-spacing: -0.03em; color: var(--text);
}
.page-hero p { font-size: 15px; color: var(--text-secondary); }

/* Back link */
.back-link {
    display: inline-flex; align-items: center; gap: 6px;
    color: var(--text-muted); font-size: 14px; font-weight: 500;
    margin-bottom: 18px; padding: 6px 0;
}
.back-link:hover { color: var(--primary); }

/* =======================================================
   FOOTER
   ======================================================= */
.footer {
    margin-top: auto; padding: 28px 40px; text-align: center;
    font-size: 13px; color: var(--text-muted);
    border-top: 1px solid var(--border); background: var(--bg-surface);
}
.footer-inner { max-width: var(--max-width); margin: 0 auto; }
.footer-brand { font-weight: 600; color: var(--text-secondary); margin-bottom: 4px; }

/* =======================================================
   LAYOUTS
   ======================================================= */
.layout-2col { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; }
.layout-3col { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.layout-sidebar { display: grid; grid-template-columns: 300px 1fr; gap: 28px; }
.layout-wide { display: grid; grid-template-columns: 2fr 1fr; gap: 28px; }
@media (max-width: 1024px) {
    .layout-2col, .layout-3col, .layout-sidebar, .layout-wide { grid-template-columns: 1fr; }
}

/* =======================================================
   UTILITY CLASSES
   ======================================================= */
.text-primary { color: var(--primary); }
.text-success { color: var(--success); }
.text-danger { color: var(--danger); }
.text-warning { color: var(--accent); }
.text-muted { color: var(--text-muted); }
.text-gradient {
    background: var(--grad-primary);
    -webkit-background-clip: text; -webkit-text-fill-color: transparent;
    background-clip: text;
}
.font-mono { font-family: 'SF Mono', 'Fira Code', monospace; }
.truncate { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }

/* =======================================================
   TAG CHIPS – For categories, filters
   ======================================================= */
.tag {
    display: inline-flex; align-items: center; gap: 4px;
    padding: 5px 12px; border-radius: var(--radius-full);
    font-size: 12px; font-weight: 600; border: 1px solid var(--border);
    background: var(--bg-surface); color: var(--text-secondary);
    transition: all var(--transition); cursor: default;
}
.tag:hover { border-color: var(--primary); color: var(--primary); background: var(--primary-light); }
.tag.active { background: var(--primary-light); color: var(--primary); border-color: rgba(99,102,241,0.3); }

/* =======================================================
   AVATAR
   ======================================================= */
.avatar {
    width: 40px; height: 40px; border-radius: 50%;
    background: var(--grad-primary); display: flex; align-items: center; justify-content: center;
    font-size: 16px; color: #fff; font-weight: 700; flex-shrink: 0;
}
.avatar-sm { width: 32px; height: 32px; font-size: 13px; }
.avatar-lg { width: 56px; height: 56px; font-size: 22px; }
.avatar-xl { width: 80px; height: 80px; font-size: 32px; }

/* =======================================================
   TOOLTIP DOTS – Animated AI indicator
   ======================================================= */
.ai-dots {
    display: inline-flex; gap: 4px; align-items: center; padding: 4px 0;
}
.ai-dots span {
    width: 6px; height: 6px; border-radius: 50%;
    background: var(--primary); animation: dotPulse 1.4s ease-in-out infinite;
}
.ai-dots span:nth-child(2) { animation-delay: 0.2s; }
.ai-dots span:nth-child(3) { animation-delay: 0.4s; }

/* =======================================================
   SCROLLBAR – Subtle, modern
   ======================================================= */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--text-dim); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--text-muted); }