:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --accent: #f59e0b;
    --accent-light: #fbbf24;
    --dark: #0f172a;
    --gray-50: #f8fafc;
    --gray-100: #f1f5f9;
    --gray-200: #e2e8f0;
    --gray-600: #475569;
    --gray-700: #334155;
    --gray-800: #1e293b;
    --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
    --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.1), 0 2px 4px -1px rgba(0,0,0,0.06);
    --shadow-xl: 0 20px 25px -5px rgba(0,0,0,0.1), 0 10px 10px -5px rgba(0,0,0,0.04);
    --radius-lg: 1.5rem;
    --radius-md: 1rem;
}
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
html {
    scroll-behavior: smooth;
}
body {
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    color: var(--gray-800);
    background: #fff;
    line-height: 1.6;
    overflow-x: hidden;
}
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0,0,0,0);
    border: 0;
}

.cookie-banner {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background: var(--dark);
    color: #fff;
    padding: 1.25rem 2rem;
    z-index: 9999;
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 1rem;
    transform: translateY(100%);
    transition: transform 0.4s ease;
    box-shadow: 0 -4px 20px rgba(0,0,0,0.2);
}
.cookie-banner.active {
    transform: translateY(0);
}
.cookie-banner p {
    flex: 1 1 300px;
    font-size: 0.95rem;
    margin: 0;
}
.cookie-banner a {
    color: var(--accent-light);
    text-decoration: underline;
}
.cookie-actions {
    display: flex;
    gap: 0.75rem;
    flex-shrink: 0;
}
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.75rem;
    font-weight: 600;
    border-radius: 2rem;
    cursor: pointer;
    transition: all 0.25s;
    border: none;
    font-size: 0.95rem;
    text-decoration: none;
}
.btn-primary {
    background: var(--primary);
    color: #fff;
}
.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}
.btn-outline-light {
    background: transparent;
    color: #fff;
    border: 2px solid rgba(255,255,255,0.4);
}
.btn-outline-light:hover {
    background: rgba(255,255,255,0.15);
}
.btn-accent {
    background: var(--accent);
    color: var(--dark);
}
.btn-accent:hover {
    background: var(--accent-light);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}
.btn-lg {
    padding: 1rem 2.25rem;
    font-size: 1.1rem;
}

.header {
    position: sticky;
    top: 0;
    z-index: 1000;
    backdrop-filter: blur(12px);
    background: rgba(255,255,255,0.8);
    border-bottom: 1px solid rgba(0,0,0,0.05);
    padding: 0.75rem 0;
}
.header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
}
.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary);
    text-decoration: none;
    letter-spacing: -0.5px;
}
.logo span {
    color: var(--accent);
}
.nav {
    display: flex;
    align-items: center;
    gap: 2rem;
}
.nav a {
    text-decoration: none;
    color: var(--gray-700);
    font-weight: 500;
    font-size: 0.95rem;
    transition: color 0.2s;
}
.nav a:hover {
    color: var(--primary);
}
.nav .btn-primary {
    padding: 0.65rem 1.5rem;
    margin-left: 1rem;
}
.mobile-menu-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 1.8rem;
    cursor: pointer;
    color: var(--gray-800);
}

.hero {
    padding: 5rem 0;
    background: linear-gradient(135deg, #0f172a 0%, #1e3a8a 100%);
    color: #fff;
    position: relative;
    overflow: hidden;
}
.hero::before {
    content: '';
    position: absolute;
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, rgba(37,99,235,0.3) 0%, transparent 70%);
    top: -200px;
    right: -150px;
    border-radius: 50%;
}
.hero .container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    align-items: center;
    position: relative;
    z-index: 1;
}
.hero-content h1 {
    font-size: clamp(2.5rem, 5vw, 3.8rem);
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 1.5rem;
}
.hero-content p {
    font-size: 1.2rem;
    margin-bottom: 2rem;
    opacity: 0.9;
}
.hero-buttons {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}
.hero-visual {
    display: flex;
    justify-content: center;
}
.hero-visual svg {
    width: 100%;
    max-width: 500px;
    height: auto;
}

.stats {
    padding: 3rem 0;
    background: var(--gray-50);
}
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 2rem;
    text-align: center;
}
.stat-item h3 {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 0.25rem;
}
.stat-item p {
    color: var(--gray-600);
    font-weight: 500;
}

.why-us {
    padding: 5rem 0;
}
.section-title {
    text-align: center;
    margin-bottom: 3rem;
}
.section-title h2 {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--dark);
    margin-bottom: 0.75rem;
}
.section-title p {
    color: var(--gray-600);
    font-size: 1.1rem;
}
.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 2rem;
}
.feature-card {
    background: #fff;
    padding: 2rem;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
    transition: transform 0.3s, box-shadow 0.3s;
    border: 1px solid var(--gray-200);
}
.feature-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-xl);
}
.feature-icon {
    width: 3rem;
    height: 3rem;
    background: rgba(37,99,235,0.1);
    border-radius: 0.75rem;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.25rem;
}
.feature-card h3 {
    margin-bottom: 0.75rem;
    font-size: 1.3rem;
}
.feature-card p {
    color: var(--gray-600);
}

.subjects-preview {
    padding: 5rem 0;
    background: var(--gray-100);
}
.subjects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
    gap: 1.5rem;
    margin-top: 2rem;
}
.subject-card {
    background: #fff;
    border-radius: var(--radius-md);
    padding: 1.5rem;
    text-align: center;
    box-shadow: var(--shadow-sm);
    transition: all 0.3s;
    cursor: default;
}
.subject-card:hover {
    transform: scale(1.05);
    box-shadow: var(--shadow-md);
}
.subject-card svg {
    width: 2.5rem;
    height: 2.5rem;
    margin-bottom: 0.75rem;
    color: var(--primary);
}
.subject-card h4 {
    font-weight: 600;
}

.how-it-works {
    padding: 5rem 0;
}
.steps {
    display: flex;
    justify-content: center;
    gap: 2rem;
    flex-wrap: wrap;
    margin-top: 2rem;
}
.step {
    flex: 1 1 220px;
    max-width: 280px;
    text-align: center;
    position: relative;
}
.step-number {
    width: 3rem;
    height: 3rem;
    background: var(--primary);
    color: #fff;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    font-weight: 700;
    margin: 0 auto 1rem;
}
.step h3 {
    margin-bottom: 0.5rem;
}
.step p {
    color: var(--gray-600);
}

.testimonials {
    padding: 5rem 0;
    background: var(--gray-50);
}
.testimonials-scroll {
    display: flex;
    gap: 1.5rem;
    overflow-x: auto;
    padding: 1rem 0;
    scroll-snap-type: x mandatory;
    -webkit-overflow-scrolling: touch;
}
.testimonial-card {
    min-width: 300px;
    max-width: 350px;
    background: #fff;
    border-radius: var(--radius-md);
    padding: 2rem;
    box-shadow: var(--shadow-md);
    scroll-snap-align: start;
    flex-shrink: 0;
    border: 1px solid var(--gray-200);
}
.testimonial-card .quote {
    font-style: italic;
    color: var(--gray-700);
    margin-bottom: 1rem;
}
.testimonial-author {
    font-weight: 600;
}

.cta-banner {
    padding: 4rem 0;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: #fff;
    text-align: center;
}
.cta-banner h2 {
    font-size: 2.2rem;
    margin-bottom: 1rem;
}
.cta-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

.footer {
    background: var(--dark);
    color: #cbd5e1;
    padding: 4rem 0 2rem;
}
.footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}
.footer-col h4 {
    color: #fff;
    margin-bottom: 1rem;
    font-weight: 600;
}
.footer-col ul {
    list-style: none;
}
.footer-col ul li {
    margin-bottom: 0.5rem;
}
.footer-col ul li a {
    color: #94a3b8;
    text-decoration: none;
    transition: color 0.2s;
}
.footer-col ul li a:hover {
    color: #fff;
}
.footer-bottom {
    border-top: 1px solid #334155;
    padding-top: 1.5rem;
    text-align: center;
    font-size: 0.9rem;
    color: #64748b;
}

.modal-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.6);
    backdrop-filter: blur(4px);
    z-index: 10000;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s;
}
.modal-overlay.active {
    opacity: 1;
    visibility: visible;
}
.modal {
    background: #fff;
    border-radius: var(--radius-lg);
    padding: 2.5rem;
    max-width: 500px;
    width: 90%;
    max-height: 90vh;
    overflow-y: auto;
    position: relative;
    box-shadow: var(--shadow-xl);
}
.modal-close {
    position: absolute;
    top: 1rem;
    right: 1rem;
    background: none;
    border: none;
    font-size: 1.8rem;
    cursor: pointer;
    color: var(--gray-600);
}
.form-group {
    margin-bottom: 1.25rem;
}
.form-group label {
    display: block;
    margin-bottom: 0.4rem;
    font-weight: 500;
}
.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 1px solid var(--gray-200);
    border-radius: 0.75rem;
    font-family: inherit;
    font-size: 1rem;
    transition: border-color 0.2s;
}
.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary);
}

@media (max-width: 768px) {
    .hero .container {
        grid-template-columns: 1fr;
    }
    .nav {
        display: none;
    }
    .mobile-menu-toggle {
        display: block;
    }
    .cookie-banner {
        flex-direction: column;
        align-items: flex-start;
    }
}