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

:root {
    --primary: #2563eb;
    --primary-light: #3b82f6;
    --secondary: #10b981;
    --accent: #f59e0b;
    --dark: #1e293b;
    --dark-light: #334155;
    --gray: #64748b;
    --gray-light: #94a3b8;
    --light: #f1f5f9;
    --white: #ffffff;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Poppins', sans-serif;
    background: var(--white);
    color: var(--dark);
    line-height: 1.6;
}

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

.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: var(--white);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
}

.navbar .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 72px;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary);
    text-decoration: none;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 32px;
    list-style: none;
}

.nav-links a {
    color: var(--gray);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s;
}

.nav-links a:hover {
    color: var(--primary);
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 24px;
    border-radius: 12px;
    font-weight: 600;
    text-decoration: none;
    transition: all 0.3s;
    border: none;
    cursor: pointer;
}

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

.btn-primary:hover {
    background: var(--primary-light);
}

.btn-outline {
    background: transparent;
    color: var(--primary);
    border: 2px solid var(--primary);
}

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

.btn-nav {
    background: var(--primary);
    color: var(--white) !important;
    padding: 10px 20px !important;
    border-radius: 12px;
}

.mobile-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
}

.mobile-toggle span {
    width: 24px;
    height: 3px;
    background: var(--primary);
    border-radius: 3px;
}

.hero {
    padding: 120px 0 80px;
    background: linear-gradient(135deg, #eff6ff 0%, #dbeafe 100%);
}

.hero .container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.hero-badge {
    display: inline-block;
    background: rgba(37, 99, 235, 0.1);
    color: var(--primary);
    padding: 8px 20px;
    border-radius: 50px;
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 20px;
}

.hero h1 {
    font-size: 3rem;
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 20px;
}

.accent {
    color: var(--secondary);
}

.hero-content p {
    font-size: 1.2rem;
    color: var(--gray);
    margin-bottom: 32px;
}

.hero-actions {
    display: flex;
    gap: 16px;
    margin-bottom: 40px;
}

.hero-stats {
    display: flex;
    gap: 40px;
}

.stat {
    display: flex;
    flex-direction: column;
}

.stat-value {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary);
}

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

.hero-visual {
    display: flex;
    justify-content: center;
}

.class-preview {
    background: var(--white);
    border-radius: 20px;
    padding: 24px;
    box-shadow: 0 20px 50px rgba(0, 0, 0, 0.1);
}

.video-call {
    display: flex;
    gap: 20px;
    margin-bottom: 20px;
}

.teacher-window, .student-window {
    flex: 1;
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    border-radius: 16px;
    padding: 32px;
    text-align: center;
    color: var(--white);
}

.avatar {
    font-size: 4rem;
    margin-bottom: 12px;
}

.teacher-window .name, .student-window .name {
    font-weight: 600;
    margin-bottom: 4px;
}

.teacher-window .label {
    font-size: 0.85rem;
    opacity: 0.9;
}

.class-tools {
    display: flex;
    justify-content: center;
    gap: 12px;
}

.tool {
    background: var(--light);
    padding: 10px 16px;
    border-radius: 8px;
    font-size: 0.85rem;
    color: var(--gray);
}

.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-header h2 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 12px;
}

.section-header p {
    color: var(--gray);
    font-size: 1.1rem;
}

.features {
    padding: 60px 0;
    background: var(--white);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.feature {
    text-align: center;
    padding: 24px;
}

.feature-icon {
    font-size: 2.5rem;
    margin-bottom: 16px;
}

.feature h3 {
    font-size: 1.1rem;
    margin-bottom: 8px;
}

.feature p {
    color: var(--gray);
    font-size: 0.9rem;
}

.courses {
    padding: 80px 0;
    background: var(--light);
}

.courses-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.course-card {
    background: var(--white);
    border-radius: 16px;
    padding: 32px;
    text-align: center;
    transition: transform 0.3s;
}

.course-card:hover {
    transform: translateY(-5px);
}

.course-icon {
    font-size: 3rem;
    margin-bottom: 16px;
}

.course-card h3 {
    font-size: 1.5rem;
    margin-bottom: 12px;
}

.course-card > p {
    color: var(--gray);
    margin-bottom: 20px;
}

.course-details {
    list-style: none;
    text-align: left;
    margin-bottom: 20px;
}

.course-details li {
    padding: 8px 0;
    color: var(--gray);
    font-size: 0.95rem;
    border-bottom: 1px solid var(--light);
}

.course-levels {
    display: inline-block;
    background: var(--primary);
    color: var(--white);
    padding: 8px 16px;
    border-radius: 20px;
    font-size: 0.85rem;
}

.method {
    padding: 80px 0;
}

.method-steps {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 32px;
}

.step {
    text-align: center;
}

.step-number {
    width: 60px;
    height: 60px;
    background: var(--primary);
    color: var(--white);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    font-weight: 700;
    margin: 0 auto 20px;
}

.step h3 {
    font-size: 1.1rem;
    margin-bottom: 8px;
}

.step p {
    color: var(--gray);
    font-size: 0.9rem;
}

.teachers {
    padding: 80px 0;
    background: var(--light);
}

.teachers-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.teacher-card {
    background: var(--white);
    border-radius: 16px;
    padding: 24px;
    text-align: center;
}

.teacher-avatar {
    font-size: 4rem;
    margin-bottom: 12px;
}

.teacher-card h4 {
    font-size: 1.25rem;
    margin-bottom: 4px;
}

.teacher-origin {
    display: block;
    color: var(--gray);
    font-size: 0.9rem;
    margin-bottom: 12px;
}

.teacher-card p {
    color: var(--gray);
    font-size: 0.85rem;
    margin-bottom: 12px;
}

.teacher-rating {
    color: var(--accent);
    font-size: 0.9rem;
}

.pricing {
    padding: 80px 0;
}

.pricing-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
    align-items: start;
}

.pricing-card {
    background: var(--white);
    border-radius: 16px;
    padding: 32px;
    text-align: center;
    border: 2px solid var(--light);
    position: relative;
}

.pricing-card.popular {
    border-color: var(--primary);
    transform: scale(1.05);
}

.popular-badge {
    position: absolute;
    top: -12px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--primary);
    color: var(--white);
    padding: 6px 16px;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 600;
}

.pricing-card h3 {
    font-size: 1.5rem;
    margin-bottom: 12px;
}

.price {
    margin-bottom: 24px;
}

.price .amount {
    font-size: 3rem;
    font-weight: 700;
    color: var(--primary);
}

.price .period {
    color: var(--gray);
}

.pricing-features {
    list-style: none;
    text-align: left;
    margin-bottom: 24px;
}

.pricing-features li {
    padding: 10px 0;
    color: var(--gray);
    border-bottom: 1px solid var(--light);
}

.pricing-features li.disabled {
    opacity: 0.5;
}

.testimonials {
    padding: 80px 0;
    background: var(--light);
}

.testimonials-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.testimonial {
    background: var(--white);
    border-radius: 16px;
    padding: 32px;
}

.testimonial-rating {
    font-size: 1.25rem;
    margin-bottom: 16px;
}

.testimonial p {
    color: var(--gray);
    margin-bottom: 20px;
    line-height: 1.8;
}

.testimonial-author strong {
    display: block;
}

.testimonial-author span {
    color: var(--primary);
    font-size: 0.9rem;
}

.cta {
    padding: 80px 0;
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    color: var(--white);
}

.cta-content {
    text-align: center;
    max-width: 600px;
    margin: 0 auto;
}

.cta-content h2 {
    font-size: 2.5rem;
    margin-bottom: 16px;
}

.cta-content > p {
    opacity: 0.9;
    margin-bottom: 32px;
}

.cta-form {
    display: flex;
    gap: 12px;
}

.cta-form input {
    flex: 1;
    padding: 14px 20px;
    border: none;
    border-radius: 12px;
    font-size: 1rem;
}

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

.footer {
    padding: 60px 0 32px;
    background: var(--dark);
    color: var(--white);
}

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

.footer-brand .logo {
    color: var(--white);
}

.footer-brand p {
    color: var(--gray);
    margin-top: 16px;
}

.footer-links h4 {
    margin-bottom: 20px;
}

.footer-links ul {
    list-style: none;
}

.footer-links li {
    margin-bottom: 10px;
}

.footer-links a {
    color: var(--gray);
    text-decoration: none;
    transition: color 0.3s;
}

.footer-links a:hover {
    color: var(--white);
}

.footer-bottom {
    text-align: center;
    padding-top: 32px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-bottom p {
    color: var(--gray);
    font-size: 0.85rem;
}

@media (max-width: 1024px) {
    .hero .container {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .hero-actions {
        justify-content: center;
    }

    .hero-stats {
        justify-content: center;
    }

    .hero-visual {
        margin-top: 40px;
    }

    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .courses-grid {
        grid-template-columns: 1fr;
        max-width: 500px;
        margin: 0 auto;
    }

    .method-steps {
        grid-template-columns: repeat(2, 1fr);
    }

    .teachers-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .pricing-grid {
        grid-template-columns: 1fr;
        max-width: 400px;
        margin: 0 auto;
    }

    .pricing-card.popular {
        transform: none;
    }

    .testimonials-grid {
        grid-template-columns: 1fr;
    }

    .footer-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
    }

    .mobile-toggle {
        display: flex;
    }

    .hero h1 {
        font-size: 2.5rem;
    }

    .features-grid {
        grid-template-columns: 1fr;
    }

    .method-steps {
        grid-template-columns: 1fr;
    }

    .teachers-grid {
        grid-template-columns: 1fr;
    }

    .hero-stats {
        flex-direction: column;
        gap: 24px;
    }

    .video-call {
        flex-direction: column;
    }

    .cta-form {
        flex-direction: column;
    }

    .footer-grid {
        grid-template-columns: 1fr;
    }
}