:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --primary-light: #3b82f6;
    --secondary: #10b981;
    --accent: #f59e0b;
    --text: #1f2937;
    --text-light: #6b7280;
    --bg: #ffffff;
    --bg-light: #f9fafb;
    --bg-card: #ffffff;
    --border: #e5e7eb;
    --shadow: 0 1px 3px rgba(0,0,0,0.1);
    --shadow-lg: 0 10px 25px rgba(0,0,0,0.1);
    --radius: 12px;
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: var(--bg-light);
    color: var(--text);
    line-height: 1.6;
    overflow-x: hidden;
}

.top-banner {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: white;
    text-align: center;
    padding: 0.75rem 1rem;
    font-size: 0.875rem;
    font-weight: 500;
}

.main-header {
    background: var(--bg);
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 100;
}

.navbar {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
}

.logo-section {
    display: flex;
    align-items: center;
}

.logo-link {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    text-decoration: none;
    color: var(--text);
}

.logo-img {
    font-size: 2rem;
}

.logo-text h1 {
    font-family: 'Lexend', sans-serif;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary);
    margin: 0;
}

.logo-text .tagline {
    font-size: 0.75rem;
    color: var(--text-light);
    font-weight: 500;
}

.nav-links {
    display: flex;
    gap: 2rem;
    list-style: none;
    align-items: center;
}

.nav-links a {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    text-decoration: none;
    color: var(--text);
    font-weight: 500;
    transition: color 0.3s;
}

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

.nav-icon {
    font-size: 1.1rem;
}

.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 4px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
}

.mobile-menu-btn span {
    width: 24px;
    height: 3px;
    background: var(--text);
    border-radius: 2px;
    transition: 0.3s;
}

main {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
}

.hero {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    align-items: center;
    padding: 4rem 0;
}

.hero-content h2 {
    font-family: 'Lexend', sans-serif;
    font-size: 3rem;
    font-weight: 700;
    color: var(--text);
    margin-bottom: 1rem;
    line-height: 1.2;
}

.hero-tagline {
    font-size: 1.25rem;
    color: var(--primary);
    font-weight: 600;
    margin-bottom: 1rem;
}

.hero-content p {
    font-size: 1.125rem;
    color: var(--text-light);
    margin-bottom: 2rem;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.cta-button {
    display: inline-block;
    padding: 1rem 2rem;
    border-radius: var(--radius);
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s;
    text-align: center;
}

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

.cta-button.primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.cta-button.secondary {
    background: transparent;
    color: var(--primary);
    border: 2px solid var(--primary);
}

.cta-button.secondary:hover {
    background: var(--primary);
    color: white;
}

.cta-button.large {
    padding: 1.25rem 2.5rem;
    font-size: 1.125rem;
}

.hero-illustration {
    display: flex;
    justify-content: center;
    align-items: center;
}

.illustration-box {
    width: 300px;
    height: 300px;
    background: linear-gradient(135deg, var(--primary-light) 0%, var(--primary) 100%);
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    box-shadow: var(--shadow-lg);
}

.grade-icon {
    font-size: 8rem;
}

.features,
.subjects-preview,
.stats,
.cta-section {
    padding: 4rem 0;
}

.section-intro {
    text-align: center;
    margin-bottom: 3rem;
}

.section-intro h2 {
    font-family: 'Lexend', sans-serif;
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--text);
    margin-bottom: 0.5rem;
}

.section-intro p {
    font-size: 1.125rem;
    color: var(--text-light);
}

.features-grid-alt {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.feature-card-large {
    background: var(--bg-card);
    padding: 2rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    transition: transform 0.3s;
}

.feature-card-large:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.feature-icon.large {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.feature-card-large h3 {
    font-family: 'Lexend', sans-serif;
    font-size: 1.5rem;
    color: var(--text);
    margin-bottom: 1rem;
}

.feature-card-large p {
    color: var(--text-light);
    margin-bottom: 1rem;
}

.feature-list {
    list-style: none;
    padding: 0;
}

.feature-list li {
    color: var(--text-light);
    padding: 0.5rem 0;
    font-size: 0.9rem;
}

.subjects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
}

.subject-card {
    background: var(--bg-card);
    padding: 2rem;
    border-radius: var(--radius);
    text-decoration: none;
    color: var(--text);
    transition: all 0.3s;
    box-shadow: var(--shadow);
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
}

.subject-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.subject-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.subject-card h3 {
    font-family: 'Lexend', sans-serif;
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
}

.subject-card p {
    color: var(--text-light);
    font-size: 0.9rem;
    margin-bottom: 1rem;
}

.card-cta {
    color: var(--primary);
    font-weight: 600;
    margin-top: auto;
}

.subject-card.math:hover {
    border-top: 4px solid #3b82f6;
}

.subject-card.science:hover {
    border-top: 4px solid #10b981;
}

.subject-card.english:hover {
    border-top: 4px solid #f59e0b;
}

.subject-card.history:hover {
    border-top: 4px solid #8b5cf6;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2rem;
}

.stat-card {
    background: var(--bg-card);
    padding: 2rem;
    border-radius: var(--radius);
    text-align: center;
    box-shadow: var(--shadow);
}

.stat-number {
    font-family: 'Lexend', sans-serif;
    font-size: 3rem;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 0.5rem;
}

.stat-label {
    color: var(--text-light);
    font-weight: 500;
}

.cta-section {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    border-radius: var(--radius);
    padding: 4rem 2rem;
    text-align: center;
    color: white;
}

.cta-content h2 {
    font-family: 'Lexend', sans-serif;
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.cta-content p {
    font-size: 1.125rem;
    margin-bottom: 2rem;
    opacity: 0.9;
}

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

.cta-content .cta-button.primary:hover {
    background: var(--bg-light);
}

.main-footer {
    background: var(--text);
    color: white;
    padding: 3rem 2rem 1rem;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h3,
.footer-section h4 {
    font-family: 'Lexend', sans-serif;
    margin-bottom: 1rem;
}

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

.footer-section ul li {
    margin-bottom: 0.5rem;
}

.footer-section a {
    color: rgba(255,255,255,0.8);
    text-decoration: none;
    transition: color 0.3s;
}

.footer-section a:hover {
    color: white;
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid rgba(255,255,255,0.1);
    color: rgba(255,255,255,0.6);
}

@media (max-width: 768px) {
    .navbar {
        padding: 1rem;
    }

    .nav-links {
        display: none;
    }

    .mobile-menu-btn {
        display: flex;
    }

    .hero {
        grid-template-columns: 1fr;
        padding: 2rem 0;
    }

    .hero-content h2 {
        font-size: 2rem;
    }

    .hero-illustration {
        display: none;
    }

    .section-intro h2 {
        font-size: 1.75rem;
    }

    main {
        padding: 1rem;
    }

    .features,
    .subjects-preview,
    .stats,
    .cta-section {
        padding: 2rem 0;
    }
}

/* Quiz Page Styles */
.quiz-container {
    max-width: 800px;
    margin: 2rem auto;
    background: var(--bg-card);
    border-radius: var(--radius);
    padding: 2rem;
    box-shadow: var(--shadow-lg);
}

.quiz-header {
    text-align: center;
    margin-bottom: 2rem;
}

.quiz-header h1 {
    font-family: 'Lexend', sans-serif;
    color: var(--primary);
    margin-bottom: 1rem;
}

.progress-bar {
    background: var(--border);
    height: 8px;
    border-radius: 4px;
    overflow: hidden;
    margin: 1rem 0;
}

.progress-fill {
    background: var(--primary);
    height: 100%;
    transition: width 0.3s;
}

.question-card {
    margin: 2rem 0;
}

.question-text {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    color: var(--text);
}

.options {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.option {
    background: var(--bg-light);
    padding: 1rem 1.5rem;
    border-radius: var(--radius);
    border: 2px solid transparent;
    cursor: pointer;
    transition: all 0.3s;
    font-size: 1rem;
}

.option:hover {
    background: var(--bg);
    border-color: var(--primary-light);
}

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

.option.correct {
    background: var(--secondary);
    color: white;
    border-color: var(--secondary);
}

.option.incorrect {
    background: #ef4444;
    color: white;
    border-color: #dc2626;
}

.quiz-controls {
    display: flex;
    justify-content: space-between;
    margin-top: 2rem;
}

.btn {
    padding: 0.75rem 2rem;
    border: none;
    border-radius: var(--radius);
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
}

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

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

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

.btn-secondary:hover {
    background: var(--text-light);
    color: white;
}

.results {
    text-align: center;
    padding: 2rem;
}

.results h2 {
    font-family: 'Lexend', sans-serif;
    font-size: 2rem;
    margin-bottom: 1rem;
}

.score-display {
    font-size: 4rem;
    font-weight: 700;
    color: var(--primary);
    margin: 2rem 0;
}

.results-message {
    font-size: 1.25rem;
    color: var(--text-light);
    margin-bottom: 2rem;
}

/* Additional Page Styles */
.page-header {
    text-align: center;
    padding: 3rem 0 2rem;
}

.page-header h1 {
    font-family: 'Lexend', sans-serif;
    font-size: 3rem;
    color: var(--text);
    margin-bottom: 1rem;
}

.page-header p {
    font-size: 1.25rem;
    color: var(--text-light);
}

.content-section {
    max-width: 1000px;
    margin: 0 auto;
}

.content-card {
    background: var(--bg-card);
    padding: 2.5rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    margin-bottom: 2rem;
}

.content-card h2 {
    font-family: 'Lexend', sans-serif;
    font-size: 2rem;
    color: var(--text);
    margin-bottom: 1.5rem;
}

.content-card p {
    color: var(--text-light);
    line-height: 1.8;
    margin-bottom: 1rem;
}

.info-list {
    list-style: none;
    padding: 0;
    margin: 1rem 0;
}

.info-list li {
    padding: 0.75rem 0;
    color: var(--text-light);
    border-bottom: 1px solid var(--border);
}

.info-list li:last-child {
    border-bottom: none;
}

.feature-item {
    text-align: center;
}

.feature-item .feature-icon {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.feature-item h3 {
    font-family: 'Lexend', sans-serif;
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
}

.feature-item p {
    font-size: 0.95rem;
    color: var(--text-light);
}

/* Subject Detail Cards */
.subjects-detail {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.subject-detail-card {
    background: var(--bg-card);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    overflow: hidden;
}

.subject-detail-header {
    display: flex;
    align-items: center;
    gap: 1.5rem;
    padding: 2rem;
    background: var(--bg-light);
}

.subject-detail-header .subject-icon {
    font-size: 3.5rem;
}

.subject-detail-header h2 {
    font-family: 'Lexend', sans-serif;
    font-size: 1.75rem;
    margin: 0;
}

.subject-detail-header p {
    color: var(--text-light);
    margin: 0;
}

.subject-detail-content {
    padding: 2rem;
}

.topic-list {
    list-style: none;
    padding: 1rem 0;
    margin: 1rem 0;
}

.topic-list li {
    padding: 0.5rem 0;
    color: var(--text-light);
}

/* Contact Page */
.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
    margin-bottom: 2rem;
}

.contact-info,
.contact-form-container {
    background: var(--bg-card);
    padding: 2rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}

.contact-info h2,
.contact-form-container h2 {
    font-family: 'Lexend', sans-serif;
    font-size: 1.75rem;
    margin-bottom: 1rem;
}

.contact-methods {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    margin: 2rem 0;
}

.contact-method {
    display: flex;
    gap: 1rem;
    align-items: flex-start;
}

.method-icon {
    font-size: 2rem;
}

.contact-method h3 {
    font-size: 1.1rem;
    margin-bottom: 0.25rem;
}

.contact-method p {
    color: var(--text-light);
    font-size: 0.95rem;
}

.info-box {
    background: var(--bg-light);
    padding: 1.5rem;
    border-radius: var(--radius);
    margin-top: 2rem;
}

.info-box h3 {
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
}

.info-box p {
    color: var(--text-light);
    font-size: 0.9rem;
}

/* Contact Form */
.contact-form {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.form-group {
    display: flex;
    flex-direction: column;
}

.form-group label {
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text);
}

.form-group input,
.form-group select,
.form-group textarea {
    padding: 0.75rem;
    border: 2px solid var(--border);
    border-radius: var(--radius);
    font-family: inherit;
    font-size: 1rem;
    transition: border-color 0.3s;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary);
}

.form-message {
    margin-top: 1rem;
    padding: 1rem;
    border-radius: var(--radius);
    text-align: center;
}

.form-message.success {
    background: #d1fae5;
    color: #065f46;
}

/* FAQ */
.faq-list {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.faq-item h3 {
    font-family: 'Lexend', sans-serif;
    font-size: 1.1rem;
    color: var(--primary);
    margin-bottom: 0.5rem;
}

.faq-item p {
    color: var(--text-light);
}

@media (max-width: 768px) {
    .contact-grid {
        grid-template-columns: 1fr;
    }
    
    .page-header h1 {
        font-size: 2rem;
    }
    
    .content-card {
        padding: 1.5rem;
    }
    
    .subject-detail-header {
        flex-direction: column;
        text-align: center;
    }
}