/* css/style.css - dSAT.uz Main Stylesheet */

:root {
    --primary: #2563EB;
    --primary-dark: #1D4ED8;
    --primary-light: #EFF6FF;
    --secondary: #7C3AED;
    --accent: #F59E0B;
    --success: #10B981;
    --danger: #EF4444;
    --warning: #F59E0B;

    --bg: #F8FAFC;
    --bg-card: #FFFFFF;
    --bg-dark: #0F172A;

    --text: #1E293B;
    --text-muted: #64748B;
    --text-light: #94A3B8;

    --border: #E2E8F0;
    --border-focus: #2563EB;

    --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
    --shadow-md: 0 4px 16px rgba(0,0,0,0.10);
    --shadow-lg: 0 8px 32px rgba(0,0,0,0.12);
    --shadow-xl: 0 20px 60px rgba(0,0,0,0.15);

    --radius: 12px;
    --radius-sm: 8px;
    --radius-lg: 20px;
    --radius-full: 9999px;

    --font-sans: 'Inter', system-ui, sans-serif;
    --font-display: 'Space Grotesk', system-ui, sans-serif;

    --transition: all 0.2s ease;
}

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

html { scroll-behavior: smooth; }

body {
    font-family: var(--font-sans);
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    min-height: 100vh;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

a { text-decoration: none; color: inherit; }

img { max-width: 100%; }

/* ============ NAVBAR ============ */
.navbar {
    background: rgba(255,255,255,0.95);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 1000;
    padding: 0;
}

.nav-inner {
    display: flex;
    align-items: center;
    gap: 24px;
    height: 68px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 8px;
    font-family: var(--font-display);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text);
    white-space: nowrap;
}

.logo-icon { font-size: 1.4rem; }
.logo-accent { color: var(--primary); }

.nav-links {
    display: flex;
    align-items: center;
    gap: 4px;
    flex: 1;
}

.nav-link {
    padding: 8px 14px;
    border-radius: var(--radius-sm);
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-muted);
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 6px;
    white-space: nowrap;
}

.nav-link:hover, .nav-link.active {
    background: var(--primary-light);
    color: var(--primary);
}

.nav-auth {
    display: flex;
    align-items: center;
    gap: 8px;
}

.hamburger {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
    margin-left: auto;
}

.hamburger span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--text);
    border-radius: 2px;
    transition: var(--transition);
}

/* ============ BUTTONS ============ */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 10px 20px;
    border-radius: var(--radius-sm);
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    border: 2px solid transparent;
    white-space: nowrap;
}

.btn-primary {
    background: var(--primary);
    color: white;
    border-color: var(--primary);
}

.btn-primary:hover {
    background: var(--primary-dark);
    border-color: var(--primary-dark);
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(37,99,235,0.3);
}

.btn-ghost {
    color: var(--text-muted);
    background: transparent;
}

.btn-ghost:hover {
    background: var(--bg);
    color: var(--text);
}

.btn-outline {
    border-color: var(--border);
    color: var(--text);
    background: transparent;
}

.btn-outline:hover {
    border-color: var(--primary);
    color: var(--primary);
}

.btn-success { background: var(--success); color: white; }
.btn-danger { background: var(--danger); color: white; }
.btn-warning { background: var(--warning); color: white; }
.btn-lg { padding: 14px 28px; font-size: 1rem; }
.btn-sm { padding: 6px 14px; font-size: 0.82rem; }
.btn-block { width: 100%; justify-content: center; }

/* ============ CARDS ============ */
.card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    box-shadow: var(--shadow-sm);
    overflow: hidden;
    transition: var(--transition);
}

.card:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.card-header {
    padding: 20px 24px;
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.card-body { padding: 24px; }
.card-footer {
    padding: 16px 24px;
    border-top: 1px solid var(--border);
    background: var(--bg);
}

/* ============ FLASH MESSAGES ============ */
.flash {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 14px 20px;
    margin: 0;
    font-weight: 500;
    font-size: 0.9rem;
}

.flash-success { background: #D1FAE5; color: #065F46; }
.flash-error   { background: #FEE2E2; color: #991B1B; }
.flash-info    { background: #DBEAFE; color: #1E40AF; }
.flash button  { margin-left: auto; background: none; border: none; cursor: pointer; font-size: 1.1rem; opacity: 0.6; }

/* ============ FORMS ============ */
.form-group { margin-bottom: 20px; }

.form-label {
    display: block;
    margin-bottom: 6px;
    font-weight: 500;
    font-size: 0.9rem;
    color: var(--text);
}

.form-control {
    width: 100%;
    padding: 12px 16px;
    border: 2px solid var(--border);
    border-radius: var(--radius-sm);
    font-size: 0.95rem;
    font-family: var(--font-sans);
    color: var(--text);
    background: white;
    transition: var(--transition);
    outline: none;
}

.form-control:focus {
    border-color: var(--border-focus);
    box-shadow: 0 0 0 3px rgba(37,99,235,0.1);
}

.form-error {
    color: var(--danger);
    font-size: 0.82rem;
    margin-top: 4px;
}

select.form-control { appearance: none; cursor: pointer; }
textarea.form-control { resize: vertical; min-height: 120px; }

/* ============ HERO SECTION ============ */
.hero {
    background: linear-gradient(135deg, #0F172A 0%, #1E3A8A 50%, #312E81 100%);
    color: white;
    padding: 100px 0;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    inset: 0;
    background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.03'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
}

.hero-content {
    position: relative;
    z-index: 1;
    max-width: 700px;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    background: rgba(255,255,255,0.1);
    border: 1px solid rgba(255,255,255,0.2);
    padding: 6px 14px;
    border-radius: var(--radius-full);
    font-size: 0.82rem;
    font-weight: 500;
    margin-bottom: 20px;
    color: rgba(255,255,255,0.9);
}

.hero h1 {
    font-family: var(--font-display);
    font-size: clamp(2rem, 5vw, 3.5rem);
    font-weight: 700;
    line-height: 1.15;
    margin-bottom: 20px;
}

.hero h1 span { color: #60A5FA; }

.hero p {
    font-size: 1.1rem;
    opacity: 0.85;
    margin-bottom: 32px;
    line-height: 1.7;
}

.hero-actions { display: flex; gap: 12px; flex-wrap: wrap; }

.hero-stats {
    display: flex;
    gap: 40px;
    margin-top: 60px;
    padding-top: 32px;
    border-top: 1px solid rgba(255,255,255,0.15);
    flex-wrap: wrap;
}

.hero-stat-value {
    font-family: var(--font-display);
    font-size: 2rem;
    font-weight: 700;
    color: #60A5FA;
}

.hero-stat-label {
    font-size: 0.85rem;
    opacity: 0.7;
    margin-top: 2px;
}

/* ============ SECTION ============ */
.section { padding: 80px 0; }
.section-sm { padding: 48px 0; }

.section-header {
    text-align: center;
    margin-bottom: 48px;
}

.section-eyebrow {
    display: inline-block;
    color: var(--primary);
    font-size: 0.82rem;
    font-weight: 700;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    margin-bottom: 8px;
}

.section-title {
    font-family: var(--font-display);
    font-size: clamp(1.5rem, 3vw, 2.2rem);
    font-weight: 700;
    color: var(--text);
    margin-bottom: 12px;
}

.section-subtitle {
    color: var(--text-muted);
    font-size: 1rem;
    max-width: 520px;
    margin: 0 auto;
}

/* ============ CATEGORY CARDS ============ */
.categories-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 24px;
}

.category-card {
    background: white;
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 32px 28px;
    cursor: pointer;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.category-card::before {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0;
    height: 4px;
    background: var(--card-color, var(--primary));
}

.category-card:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-4px);
    border-color: var(--card-color, var(--primary));
}

.category-icon {
    width: 56px;
    height: 56px;
    border-radius: var(--radius);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    margin-bottom: 16px;
    background: var(--card-color-light, var(--primary-light));
    color: var(--card-color, var(--primary));
}

.category-card h3 {
    font-family: var(--font-display);
    font-size: 1.15rem;
    font-weight: 700;
    margin-bottom: 8px;
}

.category-card p {
    color: var(--text-muted);
    font-size: 0.88rem;
    line-height: 1.6;
    margin-bottom: 20px;
}

.category-meta {
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-size: 0.82rem;
    color: var(--text-muted);
}

/* ============ TEST LIST ============ */
.tests-grid {
    display: grid;
    gap: 16px;
}

.test-item {
    background: white;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 20px 24px;
    display: flex;
    align-items: center;
    gap: 20px;
    transition: var(--transition);
}

.test-item:hover {
    border-color: var(--primary);
    box-shadow: var(--shadow-md);
}

.test-icon {
    width: 48px;
    height: 48px;
    border-radius: var(--radius-sm);
    background: var(--primary-light);
    color: var(--primary);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    flex-shrink: 0;
}

.test-info { flex: 1; }

.test-title {
    font-weight: 600;
    margin-bottom: 4px;
}

.test-meta {
    display: flex;
    gap: 16px;
    font-size: 0.82rem;
    color: var(--text-muted);
}

.test-meta span { display: flex; align-items: center; gap: 4px; }

.badge {
    display: inline-flex;
    align-items: center;
    padding: 3px 10px;
    border-radius: var(--radius-full);
    font-size: 0.75rem;
    font-weight: 600;
}

.badge-easy    { background: #D1FAE5; color: #065F46; }
.badge-medium  { background: #FEF3C7; color: #92400E; }
.badge-hard    { background: #FEE2E2; color: #991B1B; }
.badge-primary { background: var(--primary-light); color: var(--primary); }

/* ============ QUIZ / TEST AREA ============ */
.quiz-container {
    max-width: 780px;
    margin: 0 auto;
}

.quiz-header {
    background: white;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 20px 24px;
    margin-bottom: 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
}

.quiz-progress-wrap { flex: 1; }
.quiz-progress-label {
    font-size: 0.82rem;
    color: var(--text-muted);
    margin-bottom: 6px;
    display: flex;
    justify-content: space-between;
}

.progress-bar {
    height: 8px;
    background: var(--border);
    border-radius: var(--radius-full);
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary), var(--secondary));
    border-radius: var(--radius-full);
    transition: width 0.3s ease;
}

.timer-wrap {
    display: flex;
    align-items: center;
    gap: 8px;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    padding: 10px 16px;
    font-family: var(--font-display);
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--text);
    white-space: nowrap;
}

.timer-wrap.warning { color: var(--danger); border-color: var(--danger); background: #FEF2F2; }

.question-card {
    background: white;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 32px;
    margin-bottom: 20px;
}

.question-number {
    font-size: 0.82rem;
    font-weight: 600;
    color: var(--primary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 12px;
}

.question-text {
    font-size: 1.05rem;
    line-height: 1.7;
    color: var(--text);
    margin-bottom: 28px;
    white-space: pre-line;
}

.options-list { display: flex; flex-direction: column; gap: 12px; }

.option-item {
    display: flex;
    align-items: flex-start;
    gap: 14px;
    padding: 16px 20px;
    border: 2px solid var(--border);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: var(--transition);
    background: white;
}

.option-item:hover:not(.disabled) {
    border-color: var(--primary);
    background: var(--primary-light);
}

.option-item.selected {
    border-color: var(--primary);
    background: var(--primary-light);
}

.option-item.correct {
    border-color: var(--success);
    background: #D1FAE5;
}

.option-item.wrong {
    border-color: var(--danger);
    background: #FEE2E2;
}

.option-letter {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: var(--bg);
    border: 2px solid var(--border);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 0.85rem;
    flex-shrink: 0;
    transition: var(--transition);
}

.option-item.selected .option-letter {
    background: var(--primary);
    border-color: var(--primary);
    color: white;
}

.option-item.correct .option-letter  { background: var(--success); border-color: var(--success); color: white; }
.option-item.wrong .option-letter    { background: var(--danger);  border-color: var(--danger);  color: white; }

.option-text { flex: 1; font-size: 0.95rem; line-height: 1.5; padding-top: 4px; }

.explanation-box {
    background: #EFF6FF;
    border: 1px solid #BFDBFE;
    border-radius: var(--radius-sm);
    padding: 16px 20px;
    margin-top: 16px;
    font-size: 0.9rem;
    color: #1E40AF;
    display: none;
}

.explanation-box.show { display: block; }

/* ============ VOCABULARY ============ */
.vocab-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 20px;
}

.vocab-card {
    background: white;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 24px;
    cursor: pointer;
    transition: var(--transition);
}

.vocab-card:hover { box-shadow: var(--shadow-md); transform: translateY(-2px); }

.vocab-word {
    font-family: var(--font-display);
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 8px;
}

.vocab-definition { color: var(--text-muted); font-size: 0.9rem; margin-bottom: 12px; }

.vocab-example {
    font-style: italic;
    font-size: 0.85rem;
    color: var(--text-light);
    padding-left: 12px;
    border-left: 3px solid var(--border);
}

/* ============ DASHBOARD ============ */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
    margin-bottom: 32px;
}

.stat-card {
    background: white;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 24px;
}

.stat-icon {
    width: 44px;
    height: 44px;
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.1rem;
    margin-bottom: 12px;
}

.stat-value {
    font-family: var(--font-display);
    font-size: 1.8rem;
    font-weight: 700;
    margin-bottom: 4px;
}

.stat-label { font-size: 0.85rem; color: var(--text-muted); }

.score-bar-wrap { margin: 8px 0; }
.score-bar-label { display: flex; justify-content: space-between; font-size: 0.82rem; color: var(--text-muted); margin-bottom: 4px; }
.score-bar { height: 6px; background: var(--border); border-radius: 999px; overflow: hidden; }
.score-bar-fill { height: 100%; border-radius: 999px; }

/* ============ AUTH FORMS ============ */
.auth-wrapper {
    min-height: calc(100vh - 200px);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 40px 20px;
}

.auth-card {
    background: white;
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 40px;
    width: 100%;
    max-width: 440px;
    box-shadow: var(--shadow-xl);
}

.auth-logo {
    text-align: center;
    margin-bottom: 32px;
}

.auth-title {
    font-family: var(--font-display);
    font-size: 1.6rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 6px;
}

.auth-subtitle { text-align: center; color: var(--text-muted); margin-bottom: 28px; font-size: 0.9rem; }

.auth-divider {
    text-align: center;
    color: var(--text-light);
    font-size: 0.85rem;
    margin: 20px 0;
    position: relative;
}

.auth-divider::before, .auth-divider::after {
    content: '';
    position: absolute;
    top: 50%;
    width: 40%;
    height: 1px;
    background: var(--border);
}

.auth-divider::before { left: 0; }
.auth-divider::after  { right: 0; }

/* ============ ADMIN ============ */
.admin-layout {
    display: grid;
    grid-template-columns: 240px 1fr;
    min-height: calc(100vh - 68px);
}

.admin-sidebar {
    background: #0F172A;
    color: white;
    padding: 24px 0;
}

.admin-sidebar-title {
    padding: 0 20px 16px;
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: #64748B;
    border-bottom: 1px solid rgba(255,255,255,0.1);
    margin-bottom: 8px;
}

.admin-nav-link {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 20px;
    color: rgba(255,255,255,0.6);
    font-size: 0.9rem;
    transition: var(--transition);
}

.admin-nav-link:hover, .admin-nav-link.active {
    background: rgba(255,255,255,0.08);
    color: white;
}

.admin-main { padding: 32px; background: var(--bg); }

.admin-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 28px;
}

.admin-title {
    font-family: var(--font-display);
    font-size: 1.5rem;
    font-weight: 700;
}

/* ============ TABLE ============ */
.table-wrap { overflow-x: auto; border-radius: var(--radius); border: 1px solid var(--border); }

table { width: 100%; border-collapse: collapse; background: white; }

thead tr { background: var(--bg); border-bottom: 1px solid var(--border); }

th {
    padding: 12px 16px;
    text-align: left;
    font-size: 0.8rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-muted);
    white-space: nowrap;
}

td { padding: 14px 16px; border-bottom: 1px solid var(--border); font-size: 0.9rem; }

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

/* ============ RESULTS ============ */
.result-hero {
    text-align: center;
    padding: 60px 20px;
    background: linear-gradient(135deg, #EFF6FF, #F5F3FF);
    border-radius: var(--radius-lg);
    margin-bottom: 32px;
}

.result-score-circle {
    width: 140px;
    height: 140px;
    border-radius: 50%;
    background: white;
    border: 6px solid var(--primary);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    margin: 0 auto 24px;
    box-shadow: var(--shadow-lg);
}

.result-score-num {
    font-family: var(--font-display);
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--primary);
    line-height: 1;
}

.result-score-label { font-size: 0.75rem; color: var(--text-muted); font-weight: 600; }

/* ============ PAGE WRAPPER ============ */
.page-wrapper { min-height: calc(100vh - 68px); }

/* ============ FOOTER ============ */
.footer {
    background: #0F172A;
    color: rgba(255,255,255,0.7);
    padding: 64px 0 0;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 40px;
    margin-bottom: 48px;
}

.footer .logo { margin-bottom: 16px; color: white; }
.footer p { font-size: 0.88rem; line-height: 1.7; max-width: 280px; }

.footer-links h4, .footer-contact h4 {
    color: white;
    font-weight: 600;
    margin-bottom: 16px;
    font-size: 0.9rem;
}

.footer-links ul { list-style: none; }
.footer-links li { margin-bottom: 10px; }
.footer-links a { font-size: 0.88rem; transition: color 0.2s; }
.footer-links a:hover { color: white; }

.footer-contact p { font-size: 0.88rem; margin-bottom: 8px; display: flex; align-items: center; gap: 8px; max-width: none; }

.social-links { display: flex; gap: 12px; margin-top: 16px; }
.social-links a {
    width: 36px;
    height: 36px;
    border: 1px solid rgba(255,255,255,0.2);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.9rem;
    transition: var(--transition);
}

.social-links a:hover { background: rgba(255,255,255,0.1); color: white; }

.footer-bottom {
    border-top: 1px solid rgba(255,255,255,0.1);
    padding: 20px 0;
    font-size: 0.82rem;
}

/* ============ EMPTY STATE ============ */
.empty-state {
    text-align: center;
    padding: 60px 20px;
    color: var(--text-muted);
}

.empty-state-icon { font-size: 3rem; margin-bottom: 16px; }
.empty-state h3 { font-size: 1.1rem; color: var(--text); margin-bottom: 8px; }

/* ============ PAGINATION ============ */
.pagination {
    display: flex;
    justify-content: center;
    gap: 6px;
    margin-top: 32px;
}

.page-link {
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    font-size: 0.88rem;
    font-weight: 500;
    color: var(--text-muted);
    transition: var(--transition);
}

.page-link:hover, .page-link.active {
    background: var(--primary);
    border-color: var(--primary);
    color: white;
}

/* ============ RESPONSIVE ============ */
@media (max-width: 900px) {
    .footer-grid { grid-template-columns: 1fr 1fr; gap: 32px; }
    .admin-layout { grid-template-columns: 1fr; }
    .admin-sidebar { display: none; }
}

@media (max-width: 700px) {
    .nav-links { display: none; }
    .hamburger { display: flex; }
    .nav-auth { display: none; }
    .hero { padding: 64px 0; }
    .hero-stats { gap: 24px; }
    .footer-grid { grid-template-columns: 1fr; }
    .question-card { padding: 20px; }
    .auth-card { padding: 28px 20px; }
    .section { padding: 48px 0; }

    /* Mobile nav open */
    .nav-inner.open .nav-links {
        display: flex;
        flex-direction: column;
        position: fixed;
        top: 68px; left: 0; right: 0;
        background: white;
        border-bottom: 1px solid var(--border);
        padding: 16px;
        box-shadow: var(--shadow-lg);
    }

    .nav-inner.open .nav-auth {
        display: flex;
        position: fixed;
        top: 68px; left: 0; right: 0;
        background: white;
        flex-direction: column;
        padding: 0 16px 16px;
    }

    .nav-inner.open .nav-auth { top: auto; bottom: 0; }
}

/* ============ UTILITIES ============ */
.text-center { text-align: center; }
.text-muted  { color: var(--text-muted); }
.text-primary{ color: var(--primary); }
.text-success{ color: var(--success); }
.text-danger { color: var(--danger); }
.mt-1 { margin-top: 8px; }
.mt-2 { margin-top: 16px; }
.mt-3 { margin-top: 24px; }
.mt-4 { margin-top: 32px; }
.mb-1 { margin-bottom: 8px; }
.mb-2 { margin-bottom: 16px; }
.mb-3 { margin-bottom: 24px; }
.mb-4 { margin-bottom: 32px; }
.d-flex { display: flex; }
.align-center { align-items: center; }
.justify-between { justify-content: space-between; }
.gap-2 { gap: 16px; }
.fw-600 { font-weight: 600; }
.fs-sm { font-size: 0.85rem; }