:root {
    --primary-color: #fe5630;
    --primary-dark: #e54a28;
    --secondary-color: #ff7a5c;
    --accent-color: #fe5630;
    --success-color: #06d6a0;
    --warning-color: #ffd166;
    --error-color: #ef476f;
    --text-dark: #2b2d42;
    --text-light: #8d99ae;
    --bg-light: #f8f9fa;
    --bg-white: #ffffff;
    --shadow-sm: 0 2px 4px rgba(0,0,0,0.1);
    --shadow-md: 0 4px 12px rgba(0,0,0,0.15);
    --shadow-lg: 0 8px 24px rgba(0,0,0,0.2);
    --border-radius: 12px;
    --transition: all 0.3s ease;
}


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

html {
    scroll-behavior: smooth;
}

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

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

ul {
    list-style: none;
}


.main-header {
    background: var(--bg-white);
    box-shadow: var(--shadow-sm);
    position: sticky;
    top: 0;
    z-index: 1000;
}

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

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.logo-img {
    height: 40px;
    width: auto;
    object-fit: contain;
}

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

.logo h1 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

.nav-links {
    display: flex;
    gap: 2rem;
}

.nav-links a {
    font-weight: 500;
    color: var(--text-dark);
    padding: 0.5rem 1rem;
    border-radius: 8px;
    transition: var(--transition);
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--primary-color);
    background: rgba(67, 97, 238, 0.1);
}

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

.mobile-menu-btn span {
    width: 25px;
    height: 3px;
    background: var(--text-dark);
    border-radius: 2px;
    transition: var(--transition);
}


.hero {
    max-width: 1200px;
    margin: 0 auto;
    padding: 4rem 2rem;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.hero-content h2 {
    font-size: 3rem;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 1.5rem;
    line-height: 1.2;
}

.hero-content p {
    font-size: 1.2rem;
    color: var(--text-light);
    margin-bottom: 2rem;
}

.cta-button {
    display: inline-block;
    background: var(--primary-color);
    color: white;
    padding: 1rem 2rem;
    border-radius: 8px;
    font-weight: 600;
    font-size: 1rem;
    transition: background 0.2s;
}

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

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

.illustration-box {
    width: 280px;
    height: 280px;
    background: var(--primary-color);
    border-radius: 20px;
    display: flex;
    justify-content: center;
    align-items: center;
}

.grade-icon {
    font-size: 7rem;
    font-weight: 700;
    color: white;
    font-family: 'Poppins', sans-serif;
}


.features {
    max-width: 1200px;
    margin: 0 auto;
    padding: 4rem 2rem;
    text-align: center;
}

.features h2 {
    font-size: 2.5rem;
    margin-bottom: 3rem;
    color: var(--text-dark);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.feature-card {
    background: var(--bg-white);
    padding: 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
    transition: box-shadow 0.2s;
}

.feature-card:hover {
    box-shadow: var(--shadow-md);
}

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

.feature-card h3 {
    font-size: 1.3rem;
    margin-bottom: 0.5rem;
    color: var(--text-dark);
}

.feature-card p {
    color: var(--text-light);
}


.subjects-preview {
    max-width: 1200px;
    margin: 0 auto;
    padding: 4rem 2rem;
    text-align: center;
}

.subjects-preview h2 {
    font-size: 2.5rem;
    margin-bottom: 3rem;
    color: var(--text-dark);
}

.subjects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
}

.subject-card {
    background: var(--bg-white);
    padding: 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
    transition: box-shadow 0.2s;
    border-left: 4px solid transparent;
}

.subject-card:hover {
    box-shadow: var(--shadow-md);
}

.subject-card.math { border-left-color: #4361ee; }
.subject-card.science { border-left-color: #06d6a0; }
.subject-card.history { border-left-color: #ffd166; }
.subject-card.literature { border-left-color: #ef476f; }
.subject-card.geography { border-left-color: #7209b7; }
.subject-card.language { border-left-color: #f72585; }

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

.subject-card h3 {
    font-size: 1.4rem;
    margin-bottom: 0.5rem;
    color: var(--text-dark);
}

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


.stats {
    background: var(--primary-color);
    padding: 3rem 2rem;
    display: flex;
    justify-content: center;
    gap: 6rem;
    flex-wrap: wrap;
}

.stat-item {
    text-align: center;
    color: white;
}

.stat-number {
    display: block;
    font-size: 3rem;
    font-weight: 700;
}

.stat-label {
    font-size: 1.1rem;
    opacity: 0.9;
}


.grade-levels-preview {
    max-width: 1200px;
    margin: 0 auto;
    padding: 4rem 2rem;
    text-align: center;
}

.grade-levels-preview h2 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
    color: var(--text-dark);
}

.section-subtitle {
    color: var(--text-light);
    font-size: 1.1rem;
    margin-bottom: 3rem;
}

.grades-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.grade-group {
    background: var(--bg-white);
    padding: 2.5rem 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.grade-group::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
}

.grade-group.elementary::before {
    background: linear-gradient(90deg, #06d6a0, #4cc9f0);
}

.grade-group.middle::before {
    background: linear-gradient(90deg, #4361ee, #7209b7);
}

.grade-group.high::before {
    background: linear-gradient(90deg, #f72585, #ff6b6b);
}

.grade-group:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
}

.grade-icon {
    font-size: 3.5rem;
    margin-bottom: 1rem;
}

.grade-group h3 {
    font-size: 1.5rem;
    color: var(--text-dark);
    margin-bottom: 0.3rem;
}

.grade-group p {
    color: var(--text-light);
    font-size: 1rem;
    margin-bottom: 1rem;
}

.grade-badge {
    display: inline-block;
    background: var(--bg-light);
    color: var(--text-light);
    padding: 0.3rem 1rem;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 500;
}

.view-all-btn {
    display: inline-block;
    color: var(--primary-color);
    font-weight: 600;
    font-size: 1.1rem;
    padding: 0.5rem 1rem;
    transition: var(--transition);
}

.view-all-btn:hover {
    color: var(--primary-dark);
    transform: translateX(5px);
}


.grades-page {
    max-width: 1200px;
    margin: 0 auto;
    padding: 3rem 2rem;
}

.grade-section {
    margin-bottom: 4rem;
}

.grade-section h2 {
    font-size: 2rem;
    margin-bottom: 0.5rem;
    color: var(--text-dark);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.grade-section > p {
    color: var(--text-light);
    margin-bottom: 2rem;
}

.individual-grades-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
}

.grade-card {
    background: var(--bg-white);
    padding: 1.5rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    text-align: center;
    border: 2px solid transparent;
}

.grade-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-md);
    border-color: var(--primary-color);
}

.grade-card .grade-number {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.grade-card h3 {
    font-size: 1.1rem;
    color: var(--text-dark);
    margin-bottom: 0.3rem;
}

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

.grade-card .start-btn {
    display: inline-block;
    background: var(--primary-color);
    color: white;
    padding: 0.5rem 1.5rem;
    border-radius: 25px;
    font-size: 0.9rem;
    font-weight: 500;
    transition: var(--transition);
}

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


.educational-mission {
    max-width: 900px;
    margin: 0 auto;
    padding: 4rem 2rem;
    text-align: center;
}

.educational-mission h2 {
    font-size: 2rem;
    margin-bottom: 1.5rem;
    color: var(--text-dark);
}

.educational-mission p {
    color: var(--text-light);
    font-size: 1.1rem;
    margin-bottom: 1rem;
}


.main-footer {
    background: var(--text-dark);
    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;
    padding-bottom: 2rem;
    border-bottom: 1px solid rgba(255,255,255,0.1);
}

.footer-section h4 {
    font-size: 1.2rem;
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.footer-section p {
    color: rgba(255,255,255,0.7);
    font-size: 0.95rem;
}

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

.footer-section ul a {
    color: rgba(255,255,255,0.7);
    transition: var(--transition);
}

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

.footer-bottom {
    max-width: 1200px;
    margin: 0 auto;
    padding-top: 1.5rem;
    text-align: center;
}

.footer-bottom p {
    color: rgba(255,255,255,0.5);
    font-size: 0.9rem;
    margin-bottom: 0.5rem;
}


.quiz-container {
    max-width: 800px;
    margin: 0 auto;
    padding: 2rem;
}

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

.quiz-header h2 {
    font-size: 2rem;
    color: var(--text-dark);
    margin-bottom: 0.5rem;
}

.quiz-header h1 {
    font-size: 2rem;
    color: var(--text-dark);
    margin-bottom: 0.5rem;
}

.quiz-header p {
    color: var(--text-light);
}

.back-link {
    display: inline-block;
    color: var(--primary-color);
    margin-bottom: 1rem;
    font-weight: 500;
}

.back-link:hover {
    text-decoration: underline;
}

.quiz-progress {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 2rem;
}

.progress-bar {
    flex: 1;
    background: #e9ecef;
    border-radius: 10px;
    height: 10px;
    overflow: hidden;
}

.progress-fill {
    background: var(--primary-color);
    height: 100%;
    border-radius: 10px;
    transition: width 0.3s ease;
}

.progress-text {
    font-size: 0.9rem;
    color: var(--text-light);
    white-space: nowrap;
}

.quiz-progress-bar {
    background: var(--primary-color);
    height: 100%;
    border-radius: 10px;
    transition: width 0.3s ease;
}

.quiz-content {
    margin-bottom: 2rem;
}

.question-card {
    background: var(--bg-white);
    border-radius: var(--border-radius);
    padding: 2rem;
    box-shadow: var(--shadow-sm);
}

.question-card h2 {
    font-size: 1.3rem;
    color: var(--text-dark);
    margin-bottom: 1.5rem;
    line-height: 1.5;
}

#options,
.options {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

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

.question-number {
    font-size: 0.9rem;
    color: var(--primary-color);
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.question-text {
    font-size: 1.3rem;
    color: var(--text-dark);
    margin-bottom: 1.5rem;
    line-height: 1.5;
}

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

.option-btn {
    background: var(--bg-light);
    border: 2px solid #e9ecef;
    border-radius: 8px;
    padding: 1rem 1.5rem;
    text-align: left;
    font-size: 1rem;
    cursor: pointer;
    transition: border-color 0.2s, background 0.2s;
    font-family: inherit;
}

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

.option-btn.selected {
    border-color: var(--primary-color);
    background: rgba(254, 86, 48, 0.1);
}

.option-btn.correct {
    border-color: var(--success-color);
    background: rgba(6, 214, 160, 0.15);
}

.option-btn.incorrect {
    border-color: var(--error-color);
    background: rgba(239, 71, 111, 0.15);
}

.quiz-navigation {
    display: flex;
    justify-content: space-between;
    gap: 1rem;
}

.nav-btn {
    padding: 0.8rem 2rem;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    font-family: inherit;
    background: var(--bg-light);
    color: var(--text-dark);
    transition: background 0.2s;
}

.nav-btn:hover {
    background: #e9ecef;
}

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

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

.nav-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.quiz-btn {
    padding: 0.8rem 2rem;
    border: none;
    border-radius: 50px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    font-family: inherit;
}

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

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

.quiz-btn.secondary {
    background: var(--bg-light);
    color: var(--text-dark);
}

.quiz-btn.secondary:hover {
    background: #e9ecef;
}

.quiz-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}


.quiz-results {
    text-align: center;
    padding: 3rem 2rem;
}

.results-card {
    background: var(--bg-white);
    border-radius: var(--border-radius);
    padding: 3rem 2rem;
    box-shadow: var(--shadow-sm);
    max-width: 500px;
    margin: 0 auto;
}

.results-card h2 {
    font-size: 1.8rem;
    color: var(--text-dark);
    margin-bottom: 1.5rem;
}

.score-circle {
    display: flex;
    flex-direction: column;
    align-items: center;
    margin-bottom: 1.5rem;
}

.score-circle .score {
    font-size: 4rem;
    font-weight: 700;
    color: var(--primary-color);
    line-height: 1;
}

.score-circle .score-label {
    font-size: 1rem;
    color: var(--text-light);
}

.score-message {
    font-size: 1.1rem;
    color: var(--text-dark);
    margin-bottom: 2rem;
}

.results-actions {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

.btn-restart,
.btn-back {
    padding: 0.8rem 1.5rem;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    font-family: inherit;
    text-decoration: none;
    border: none;
}

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

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

.btn-back {
    background: var(--bg-light);
    color: var(--text-dark);
}

.btn-back:hover {
    background: #e9ecef;
}

.results-icon {
    font-size: 5rem;
    margin-bottom: 1rem;
}

.results-score {
    font-size: 3rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.results-message {
    font-size: 1.3rem;
    color: var(--text-dark);
    margin-bottom: 1rem;
}

.results-details {
    color: var(--text-light);
    margin-bottom: 2rem;
}


.page-header {
    background: var(--primary-color);
    color: white;
    padding: 3rem 2rem;
    text-align: center;
}

.page-header h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.page-header p {
    font-size: 1.2rem;
    opacity: 0.9;
    max-width: 600px;
    margin: 0 auto;
}

.page-content {
    max-width: 900px;
    margin: 0 auto;
    padding: 3rem 2rem;
}

.page-content h3 {
    font-size: 1.5rem;
    color: var(--text-dark);
    margin: 2rem 0 1rem;
}

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

.contact-form {
    background: var(--bg-white);
    padding: 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: var(--text-dark);
}

.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 0.8rem 1rem;
    border: 2px solid #e9ecef;
    border-radius: 8px;
    font-size: 1rem;
    font-family: inherit;
    transition: var(--transition);
}

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

.form-group textarea {
    min-height: 150px;
    resize: vertical;
}

.submit-btn {
    background: var(--primary-color);
    color: white;
    padding: 1rem 2rem;
    border: none;
    border-radius: 50px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    font-family: inherit;
}

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


.subjects-page {
    max-width: 1200px;
    margin: 0 auto;
    padding: 3rem 2rem;
}

.subjects-page h2 {
    text-align: center;
    font-size: 2rem;
    margin-bottom: 2rem;
    color: var(--text-dark);
}

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

.subject-full-card {
    background: var(--bg-white);
    border-radius: var(--border-radius);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    transition: box-shadow 0.2s;
}

.subject-full-card:hover {
    box-shadow: var(--shadow-md);
}

.subject-full-card .card-header {
    padding: 2rem;
    text-align: center;
}

.subject-full-card.math .card-header { background: #4361ee; }
.subject-full-card.science .card-header { background: #06d6a0; }
.subject-full-card.history .card-header { background: #ffd166; }
.subject-full-card.literature .card-header { background: #ef476f; }
.subject-full-card.geography .card-header { background: #7209b7; }
.subject-full-card.language .card-header { background: #f72585; }

.subject-full-card .card-header .icon {
    font-size: 4rem;
    margin-bottom: 1rem;
}

.subject-full-card .card-header h3 {
    color: white;
    font-size: 1.5rem;
}

.subject-full-card .card-body {
    padding: 1.5rem;
}

.subject-full-card .card-body p {
    color: var(--text-light);
    margin-bottom: 1rem;
}

.subject-full-card .card-body ul {
    margin-bottom: 1.5rem;
}

.subject-full-card .card-body li {
    color: var(--text-dark);
    padding: 0.3rem 0;
    padding-left: 1.5rem;
    position: relative;
}

.subject-full-card .card-body li::before {
    content: "✓";
    position: absolute;
    left: 0;
    color: var(--success-color);
}

.start-quiz-btn {
    display: block;
    text-align: center;
    background: var(--primary-color);
    color: white;
    padding: 0.8rem;
    border-radius: 8px;
    font-weight: 600;
    transition: var(--transition);
}

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


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

    .nav-links {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: var(--bg-white);
        flex-direction: column;
        padding: 1rem;
        gap: 0;
        box-shadow: var(--shadow-md);
    }

    .nav-links.active {
        display: flex;
    }

    .nav-links li {
        width: 100%;
    }

    .nav-links a {
        display: block;
        padding: 1rem;
    }

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

    .hero {
        grid-template-columns: 1fr;
        text-align: center;
        padding: 2rem 1rem;
    }

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

    .hero-illustration {
        order: -1;
    }

    .illustration-box {
        width: 180px;
        height: 180px;
    }

    .grade-icon {
        font-size: 5rem;
    }

    .features h2,
    .subjects-preview h2 {
        font-size: 1.8rem;
    }

    .stats {
        gap: 3rem;
    }

    .stat-number {
        font-size: 2rem;
    }

    .quiz-navigation {
        flex-direction: column;
    }

    .page-header h2 {
        font-size: 1.8rem;
    }
}

@media (max-width: 480px) {
    .hero-content h2 {
        font-size: 1.6rem;
    }

    .cta-button {
        padding: 0.8rem 1.5rem;
        font-size: 1rem;
    }

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

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




.subject-hero {
    background: var(--primary-color);
    padding: 3rem 2rem;
    text-align: center;
    color: white;
}

.subject-hero-content {
    max-width: 600px;
    margin: 0 auto;
}

.subject-icon-large {
    font-size: 4rem;
    margin-bottom: 1rem;
    display: block;
}

.subject-hero h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
}

.subject-hero p {
    font-size: 1.1rem;
    opacity: 0.9;
}


.math-hero {
    background: #fe5630;
}


.science-hero {
    background: #06d6a0;
}


.history-hero {
    background: #ffd166;
}


.literature-hero {
    background: #9b59b6;
}


.geography-hero {
    background: #3498db;
}


.language-hero {
    background: #e74c3c;
}


.grade-selection {
    max-width: 1200px;
    margin: 0 auto;
    padding: 3rem 2rem;
}

.grade-selection h2 {
    text-align: center;
    font-size: 2rem;
    color: var(--text-dark);
    margin-bottom: 2rem;
}

.grade-group-section {
    margin-bottom: 3rem;
}

.grade-group-title {
    font-size: 1.3rem;
    padding: 0.8rem 1.5rem;
    border-radius: 30px;
    display: inline-block;
    margin-bottom: 1.5rem;
    color: white;
}

.elementary-title {
    background: #06d6a0;
}

.middle-title {
    background: #3498db;
}

.high-title {
    background: #9b59b6;
}

.grade-cards {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 1rem;
}

.grade-card {
    background: white;
    border-radius: var(--border-radius);
    padding: 1.5rem;
    text-align: center;
    box-shadow: var(--shadow-sm);
    transition: box-shadow 0.2s;
    border: 2px solid transparent;
    text-decoration: none;
    color: inherit;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

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

.grade-card .grade-level {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

.grade-card .grade-name {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-dark);
}

.grade-card .grade-topics {
    font-size: 0.85rem;
    color: var(--text-light);
}


.back-to-subjects {
    text-align: center;
    padding: 2rem;
}

.back-btn {
    display: inline-block;
    padding: 0.8rem 2rem;
    background: var(--bg-light);
    color: var(--text-dark);
    border-radius: 30px;
    font-weight: 500;
    transition: var(--transition);
}

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


a.subject-full-card {
    display: block;
    text-decoration: none;
    color: inherit;
    cursor: pointer;
}

a.subject-full-card:hover {
    box-shadow: var(--shadow-lg);
}

.select-grade-btn {
    display: inline-block;
    padding: 0.8rem 1.5rem;
    background: var(--primary-color);
    color: white;
    border-radius: 30px;
    font-weight: 500;
    transition: var(--transition);
    margin-top: 1rem;
}

a.subject-full-card:hover .select-grade-btn {
    background: var(--primary-dark);
}


.section-subtitle {
    text-align: center;
    color: var(--text-light);
    margin-bottom: 2rem;
    font-size: 1.1rem;
}


@media (max-width: 768px) {
    .subject-hero {
        padding: 3rem 1.5rem;
    }

    .subject-hero h1 {
        font-size: 2rem;
    }

    .subject-icon-large {
        font-size: 3rem;
    }

    .grade-cards {
        grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
    }

    .grade-card .grade-level {
        font-size: 2rem;
    }
}