/* AI Learn Pros — Modern Dark Theme */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800;900&family=Space+Grotesk:wght@400;500;600;700&display=swap');

:root {
    --primary: #6366F1;
    --primary-light: #818CF8;
    --primary-dark: #4F46E5;
    --accent: #06B6D4;
    --accent-light: #22D3EE;
    --success: #10B981;
    --warning: #F59E0B;
    --danger: #EF4444;
    --bg-body: #0A0A0F;
    --bg-card: #12121A;
    --bg-card-hover: #1A1A26;
    --bg-input: #1A1A26;
    --bg-nav: rgba(10, 10, 15, 0.9);
    --text-primary: #F1F1F4;
    --text-secondary: #9CA3AF;
    --text-muted: #6B7280;
    --border-color: #1F1F2E;
    --border-hover: #2D2D40;
    --gradient-primary: linear-gradient(135deg, #6366F1, #06B6D4);
    --gradient-dark: linear-gradient(135deg, #12121A, #1A1A26);
    --glow-primary: 0 0 20px rgba(99, 102, 241, 0.3);
    --glow-accent: 0 0 20px rgba(6, 182, 212, 0.3);
    --radius: 12px;
    --radius-lg: 20px;
    --radius-full: 9999px;
    --font-body: 'Inter', -apple-system, sans-serif;
    --font-display: 'Space Grotesk', sans-serif;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
    font-family: var(--font-body);
    background: var(--bg-body);
    color: var(--text-primary);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

a { color: var(--primary-light); text-decoration: none; transition: var(--transition); }
a:hover { color: var(--accent-light); }

.container { max-width: 1200px; margin: 0 auto; padding: 0 24px; }
.container-sm { max-width: 800px; margin: 0 auto; padding: 0 24px; }

/* Navigation */
.nav {
    position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
    background: var(--bg-nav); backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-color);
    padding: 16px 0;
    transition: var(--transition);
}
.nav-inner {
    display: flex; align-items: center; justify-content: space-between;
    max-width: 1200px; margin: 0 auto; padding: 0 24px;
}
.nav-logo {
    font-family: var(--font-display); font-size: 22px; font-weight: 700;
    background: var(--gradient-primary); -webkit-background-clip: text; -webkit-text-fill-color: transparent;
}
.nav-links { display: flex; align-items: center; gap: 32px; list-style: none; }
.nav-links a {
    color: var(--text-secondary); font-size: 15px; font-weight: 500;
    transition: var(--transition); position: relative;
}
.nav-links a:hover, .nav-links a.active { color: var(--text-primary); }
.nav-links a.active::after {
    content: ''; position: absolute; bottom: -6px; left: 0; right: 0;
    height: 2px; background: var(--gradient-primary); border-radius: 2px;
}
.nav-cta {
    background: var(--gradient-primary) !important; color: #fff !important;
    padding: 10px 24px !important; border-radius: var(--radius-full) !important;
    font-weight: 600 !important; font-size: 14px !important;
    -webkit-text-fill-color: #fff !important;
}
.nav-cta:hover { box-shadow: var(--glow-primary); transform: translateY(-1px); }

.mobile-toggle { display: none; background: none; border: none; color: var(--text-primary); font-size: 24px; cursor: pointer; }

/* Buttons */
.btn {
    display: inline-flex; align-items: center; gap: 8px;
    padding: 12px 28px; border-radius: var(--radius);
    font-family: var(--font-body); font-size: 15px; font-weight: 600;
    border: none; cursor: pointer; transition: var(--transition);
    text-decoration: none; line-height: 1.4;
}
.btn-primary {
    background: var(--gradient-primary); color: #fff;
    box-shadow: 0 4px 15px rgba(99, 102, 241, 0.3);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: var(--glow-primary); color: #fff; }
.btn-secondary {
    background: transparent; color: var(--text-primary);
    border: 2px solid var(--border-color);
}
.btn-secondary:hover { border-color: var(--primary); color: var(--primary-light); }
.btn-accent { background: var(--accent); color: #fff; }
.btn-accent:hover { background: var(--accent-light); color: #fff; }
.btn-danger { background: var(--danger); color: #fff; }
.btn-sm { padding: 8px 18px; font-size: 13px; }
.btn-lg { padding: 16px 36px; font-size: 17px; border-radius: var(--radius-lg); }
.btn-block { width: 100%; justify-content: center; }
.btn:disabled { opacity: 0.5; cursor: not-allowed; transform: none !important; }

/* Hero */
.hero {
    padding: 160px 0 100px; text-align: center; position: relative; overflow: hidden;
}
.hero::before {
    content: ''; position: absolute; top: -50%; left: -50%; width: 200%; height: 200%;
    background: radial-gradient(ellipse at 30% 50%, rgba(99,102,241,0.08) 0%, transparent 60%),
                radial-gradient(ellipse at 70% 50%, rgba(6,182,212,0.06) 0%, transparent 60%);
    animation: heroGlow 8s ease-in-out infinite alternate;
}
@keyframes heroGlow {
    0% { transform: translate(0, 0); }
    100% { transform: translate(-3%, 3%); }
}
.hero-content { position: relative; z-index: 1; }
.hero-badge {
    display: inline-flex; align-items: center; gap: 8px;
    background: rgba(99,102,241,0.1); border: 1px solid rgba(99,102,241,0.2);
    padding: 8px 20px; border-radius: var(--radius-full);
    font-size: 14px; font-weight: 500; color: var(--primary-light);
    margin-bottom: 24px;
}
.hero h1 {
    font-family: var(--font-display); font-size: clamp(40px, 6vw, 72px);
    font-weight: 800; line-height: 1.1; margin-bottom: 24px;
    letter-spacing: -1px;
}
.hero h1 .gradient-text {
    background: var(--gradient-primary); -webkit-background-clip: text; -webkit-text-fill-color: transparent;
}
.hero p {
    font-size: clamp(17px, 2vw, 20px); color: var(--text-secondary);
    max-width: 640px; margin: 0 auto 40px; line-height: 1.7;
}
.hero-buttons { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }
.hero-stats {
    display: flex; justify-content: center; gap: 48px; margin-top: 64px;
    padding-top: 40px; border-top: 1px solid var(--border-color);
}
.hero-stat { text-align: center; }
.hero-stat .number {
    font-family: var(--font-display); font-size: 36px; font-weight: 700;
    background: var(--gradient-primary); -webkit-background-clip: text; -webkit-text-fill-color: transparent;
}
.hero-stat .label { font-size: 14px; color: var(--text-muted); margin-top: 4px; }

/* Sections */
.section { padding: 100px 0; }
.section-header { text-align: center; margin-bottom: 60px; }
.section-header h2 {
    font-family: var(--font-display); font-size: clamp(28px, 4vw, 42px);
    font-weight: 700; margin-bottom: 16px;
}
.section-header p { color: var(--text-secondary); font-size: 18px; max-width: 600px; margin: 0 auto; }

/* Cards */
.card {
    background: var(--bg-card); border: 1px solid var(--border-color);
    border-radius: var(--radius-lg); padding: 32px; transition: var(--transition);
}
.card:hover { border-color: var(--border-hover); transform: translateY(-4px); box-shadow: 0 20px 40px rgba(0,0,0,0.3); }

/* Grid */
.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 24px; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }

/* Features */
.feature-icon {
    width: 56px; height: 56px; border-radius: var(--radius);
    display: flex; align-items: center; justify-content: center;
    font-size: 24px; margin-bottom: 20px;
    background: linear-gradient(135deg, rgba(99,102,241,0.1), rgba(6,182,212,0.1));
    color: var(--primary-light);
}
.feature-card h3 { font-family: var(--font-display); font-size: 20px; font-weight: 600; margin-bottom: 12px; }
.feature-card p { color: var(--text-secondary); font-size: 15px; line-height: 1.7; }

/* Pricing */
.pricing-card { position: relative; text-align: center; }
.pricing-card.featured {
    border-color: var(--primary); box-shadow: var(--glow-primary);
    transform: scale(1.03);
}
.pricing-card.featured::before {
    content: 'Most Popular'; position: absolute; top: -12px; left: 50%; transform: translateX(-50%);
    background: var(--gradient-primary); color: #fff; padding: 4px 20px;
    border-radius: var(--radius-full); font-size: 12px; font-weight: 700; text-transform: uppercase;
}
.pricing-card .plan-name { font-family: var(--font-display); font-size: 22px; font-weight: 600; margin-bottom: 8px; }
.pricing-card .plan-price {
    font-family: var(--font-display); font-size: 48px; font-weight: 800; margin: 16px 0 8px;
}
.pricing-card .plan-price span { font-size: 16px; color: var(--text-muted); font-weight: 400; }
.pricing-card .plan-desc { color: var(--text-secondary); font-size: 14px; margin-bottom: 24px; }
.pricing-card .plan-features { list-style: none; text-align: left; margin-bottom: 32px; }
.pricing-card .plan-features li {
    padding: 8px 0; color: var(--text-secondary); font-size: 14px;
    display: flex; align-items: flex-start; gap: 10px;
}
.pricing-card .plan-features li::before {
    content: '\f00c'; font-family: 'Font Awesome 6 Free'; font-weight: 900;
    color: var(--success); font-size: 12px; margin-top: 3px; flex-shrink: 0;
}

/* Testimonials */
.testimonial-card { position: relative; }
.testimonial-card .stars { color: var(--warning); font-size: 14px; margin-bottom: 16px; }
.testimonial-card .quote { color: var(--text-secondary); font-size: 15px; line-height: 1.7; margin-bottom: 20px; font-style: italic; }
.testimonial-card .author { display: flex; align-items: center; gap: 12px; }
.testimonial-card .author-avatar {
    width: 44px; height: 44px; border-radius: 50%;
    background: var(--gradient-primary); display: flex; align-items: center; justify-content: center;
    color: #fff; font-weight: 700; font-size: 16px;
}
.testimonial-card .author-name { font-weight: 600; font-size: 15px; }
.testimonial-card .author-role { font-size: 13px; color: var(--text-muted); }

/* Classes Grid */
.class-card { overflow: hidden; padding: 0; }
.class-card .class-thumb {
    height: 180px; background: var(--gradient-dark);
    display: flex; align-items: center; justify-content: center;
    font-size: 48px; color: var(--primary);
}
.class-card .class-body { padding: 24px; }
.class-card .class-meta {
    display: flex; align-items: center; gap: 16px; margin-bottom: 12px;
    font-size: 13px; color: var(--text-muted);
}
.class-card .class-title { font-family: var(--font-display); font-size: 18px; font-weight: 600; margin-bottom: 8px; }
.class-card .class-desc { color: var(--text-secondary); font-size: 14px; line-height: 1.6; margin-bottom: 16px; }
.class-card .class-footer {
    display: flex; align-items: center; justify-content: space-between;
    padding-top: 16px; border-top: 1px solid var(--border-color);
}
.class-card .class-price { font-family: var(--font-display); font-size: 22px; font-weight: 700; color: var(--accent); }
.class-card .class-spots { font-size: 13px; color: var(--text-muted); }

/* Tutorial Cards */
.tutorial-card { overflow: hidden; padding: 0; }
.tutorial-card .tutorial-thumb {
    height: 180px; background: var(--gradient-dark); position: relative;
    display: flex; align-items: center; justify-content: center;
}
.tutorial-card .tutorial-thumb .play-btn {
    width: 60px; height: 60px; border-radius: 50%;
    background: rgba(255,255,255,0.15); backdrop-filter: blur(10px);
    display: flex; align-items: center; justify-content: center;
    font-size: 20px; color: #fff; transition: var(--transition);
}
.tutorial-card:hover .play-btn { background: var(--primary); transform: scale(1.1); }
.tutorial-card .tutorial-thumb .duration {
    position: absolute; bottom: 10px; right: 10px;
    background: rgba(0,0,0,0.7); padding: 3px 10px; border-radius: 4px;
    font-size: 12px; font-weight: 600;
}
.tutorial-card .tutorial-body { padding: 20px; }
.tutorial-card .tutorial-title { font-family: var(--font-display); font-size: 16px; font-weight: 600; margin-bottom: 8px; }
.tutorial-card .tutorial-desc { color: var(--text-secondary); font-size: 13px; line-height: 1.6; margin-bottom: 12px; }
.tutorial-card .tutorial-meta { display: flex; align-items: center; gap: 12px; font-size: 12px; color: var(--text-muted); }
.tutorial-card .free-badge {
    background: rgba(16,185,129,0.15); color: var(--success);
    padding: 2px 10px; border-radius: var(--radius-full); font-size: 11px; font-weight: 700;
}
.tutorial-card .locked-badge {
    background: rgba(99,102,241,0.15); color: var(--primary-light);
    padding: 2px 10px; border-radius: var(--radius-full); font-size: 11px; font-weight: 700;
}

/* Forms */
.form-group { margin-bottom: 20px; }
.form-group label { display: block; font-size: 14px; font-weight: 500; margin-bottom: 8px; color: var(--text-secondary); }
.form-control {
    width: 100%; padding: 12px 16px; background: var(--bg-input); border: 1px solid var(--border-color);
    border-radius: var(--radius); color: var(--text-primary); font-family: var(--font-body);
    font-size: 15px; transition: var(--transition);
}
.form-control:focus { outline: none; border-color: var(--primary); box-shadow: 0 0 0 3px rgba(99,102,241,0.15); }
.form-control::placeholder { color: var(--text-muted); }
textarea.form-control { min-height: 120px; resize: vertical; }
select.form-control { appearance: none; background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%239CA3AF' stroke-width='2'%3E%3Cpath d='M6 9l6 6 6-6'/%3E%3C/svg%3E"); background-repeat: no-repeat; background-position: right 12px center; }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }

/* Flash Messages */
.flash {
    padding: 16px 20px; border-radius: var(--radius); margin-bottom: 24px;
    display: flex; align-items: center; gap: 12px; font-size: 14px; font-weight: 500;
}
.flash-success { background: rgba(16,185,129,0.1); border: 1px solid rgba(16,185,129,0.2); color: var(--success); }
.flash-danger { background: rgba(239,68,68,0.1); border: 1px solid rgba(239,68,68,0.2); color: var(--danger); }
.flash-warning { background: rgba(245,158,11,0.1); border: 1px solid rgba(245,158,11,0.2); color: var(--warning); }
.flash-info { background: rgba(99,102,241,0.1); border: 1px solid rgba(99,102,241,0.2); color: var(--primary-light); }

/* Dashboard */
.dash-grid { display: grid; grid-template-columns: 260px 1fr; gap: 32px; min-height: calc(100vh - 80px); }
.dash-sidebar {
    background: var(--bg-card); border-right: 1px solid var(--border-color);
    padding: 32px 20px;
}
.dash-sidebar .nav-item {
    display: flex; align-items: center; gap: 12px;
    padding: 12px 16px; border-radius: var(--radius);
    color: var(--text-secondary); font-size: 14px; font-weight: 500;
    transition: var(--transition); margin-bottom: 4px;
}
.dash-sidebar .nav-item:hover, .dash-sidebar .nav-item.active {
    background: rgba(99,102,241,0.1); color: var(--primary-light);
}
.dash-sidebar .nav-item i { width: 20px; text-align: center; }
.dash-main { padding: 32px; }
.dash-header { margin-bottom: 32px; }
.dash-header h1 { font-family: var(--font-display); font-size: 28px; font-weight: 700; }

.stat-cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 16px; margin-bottom: 32px; }
.stat-card {
    background: var(--bg-card); border: 1px solid var(--border-color);
    border-radius: var(--radius); padding: 24px;
}
.stat-card .stat-label { font-size: 13px; color: var(--text-muted); margin-bottom: 8px; }
.stat-card .stat-value { font-family: var(--font-display); font-size: 28px; font-weight: 700; }
.stat-card .stat-icon { float: right; font-size: 24px; color: var(--primary); opacity: 0.5; }

/* Tables */
.table-wrapper { overflow-x: auto; }
table { width: 100%; border-collapse: collapse; }
th { text-align: left; padding: 12px 16px; font-size: 12px; text-transform: uppercase; letter-spacing: 0.05em; color: var(--text-muted); border-bottom: 1px solid var(--border-color); }
td { padding: 16px; font-size: 14px; border-bottom: 1px solid var(--border-color); }
tr:hover td { background: rgba(99,102,241,0.03); }

/* Footer */
.footer {
    background: var(--bg-card); border-top: 1px solid var(--border-color);
    padding: 60px 0 30px;
}
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 40px; margin-bottom: 40px; }
.footer-brand p { color: var(--text-secondary); font-size: 14px; line-height: 1.7; margin-top: 12px; }
.footer h4 { font-family: var(--font-display); font-size: 14px; font-weight: 600; margin-bottom: 16px; text-transform: uppercase; letter-spacing: 0.05em; }
.footer-links { list-style: none; }
.footer-links li { margin-bottom: 10px; }
.footer-links a { color: var(--text-muted); font-size: 14px; }
.footer-links a:hover { color: var(--text-primary); }
.footer-bottom { border-top: 1px solid var(--border-color); padding-top: 24px; text-align: center; font-size: 13px; color: var(--text-muted); }

/* FAQ */
.faq-item { border-bottom: 1px solid var(--border-color); }
.faq-question {
    padding: 20px 0; font-size: 16px; font-weight: 600; cursor: pointer;
    display: flex; justify-content: space-between; align-items: center;
}
.faq-question::after { content: '\f078'; font-family: 'Font Awesome 6 Free'; font-weight: 900; font-size: 14px; color: var(--text-muted); transition: var(--transition); }
.faq-item.open .faq-question::after { transform: rotate(180deg); color: var(--primary); }
.faq-answer { max-height: 0; overflow: hidden; transition: max-height 0.3s ease; }
.faq-item.open .faq-answer { max-height: 500px; }
.faq-answer p { padding-bottom: 20px; color: var(--text-secondary); font-size: 15px; line-height: 1.7; }

/* Progress Bar */
.progress-bar { background: var(--border-color); border-radius: var(--radius-full); height: 8px; overflow: hidden; }
.progress-bar .progress-fill {
    height: 100%; border-radius: var(--radius-full);
    background: var(--gradient-primary); transition: width 0.5s ease;
}

/* Pagination */
.pagination { display: flex; gap: 8px; justify-content: center; margin-top: 40px; }
.pagination a, .pagination span {
    padding: 8px 14px; border-radius: var(--radius); font-size: 14px;
    border: 1px solid var(--border-color); color: var(--text-secondary);
}
.pagination a:hover { border-color: var(--primary); color: var(--primary-light); }
.pagination .active { background: var(--primary); border-color: var(--primary); color: #fff; }

/* Responsive */
@media (max-width: 768px) {
    .nav-links { display: none; }
    .nav-links.open {
        display: flex; flex-direction: column; position: absolute;
        top: 100%; left: 0; right: 0; background: var(--bg-card);
        padding: 20px; gap: 16px; border-bottom: 1px solid var(--border-color);
    }
    .mobile-toggle { display: block; }
    .hero { padding: 120px 0 60px; }
    .hero-stats { gap: 24px; }
    .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
    .pricing-card.featured { transform: none; }
    .footer-grid { grid-template-columns: 1fr; }
    .dash-grid { grid-template-columns: 1fr; }
    .dash-sidebar { display: none; }
    .form-row { grid-template-columns: 1fr; }
    .hero-buttons { flex-direction: column; align-items: center; }
}
@media (max-width: 1024px) and (min-width: 769px) {
    .grid-4 { grid-template-columns: repeat(2, 1fr); }
    .grid-3 { grid-template-columns: repeat(2, 1fr); }
    .footer-grid { grid-template-columns: 1fr 1fr; }
}