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

:root {
    --primary-color: #2c3e50;
    --secondary-color: #3498db;
    --accent-color: #e74c3c;
    --success-color: #27ae60;
    --warning-color: #f39c12;
    --light-bg: #ecf0f1;
    --white: #ffffff;
    --dark-text: #2c3e50;
    --border-radius: 8px;
    --box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: var(--dark-text);
    background-color: #f5f5f5;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header & Navigation */
header {
    background-color: var(--primary-color);
    color: white;
    padding: 1rem 0;
    box-shadow: var(--box-shadow);
    position: sticky;
    top: 0;
    z-index: 100;
}

.navbar {
    width: 100%;
}

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

.logo {
    font-size: 1.5rem;
    font-weight: bold;
}

.logo a {
    color: white;
    text-decoration: none;
}

.logo-text {
    display: inline-block;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-menu a {
    color: white;
    text-decoration: none;
    transition: color 0.3s ease;
    padding: 0.5rem 1rem;
}

.nav-menu a:hover,
.nav-menu a.active {
    color: var(--secondary-color);
    background-color: rgba(255, 255, 255, 0.1);
    border-radius: var(--border-radius);
}

.language-switch {
    margin-left: auto;
}

.lang-btn {
    color: white;
    text-decoration: none;
    padding: 0.5rem 1rem;
    border: 1px solid white;
    border-radius: var(--border-radius);
    transition: all 0.3s ease;
}

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

/* Footer */
footer {
    background-color: var(--primary-color);
    color: white;
    padding: 2rem 0;
    margin-top: 4rem;
    text-align: center;
}

.footer-content p {
    margin: 0.5rem 0;
}

/* Main Content */
main {
    min-height: calc(100vh - 200px);
    padding: 2rem 0;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: var(--border-radius);
    font-size: 1rem;
    cursor: pointer;
    text-decoration: none;
    transition: all 0.3s ease;
    font-weight: 500;
}

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

.btn-primary:hover {
    background-color: #2980b9;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(52, 152, 219, 0.3);
}

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

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

.btn-small {
    padding: 0.5rem 1rem;
    font-size: 0.9rem;
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: white;
    padding: 4rem 0;
    text-align: center;
}

.hero h1 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.hero .subtitle {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    opacity: 0.95;
}

.hero .description {
    font-size: 1.1rem;
    margin-bottom: 2rem;
    opacity: 0.9;
}

.cta-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

/* Cards */
.cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin: 2rem 0;
}

.card {
    background: white;
    padding: 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    text-align: center;
    transition: transform 0.3s ease;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.15);
}

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

.card h3 {
    margin-bottom: 0.5rem;
    color: var(--primary-color);
}

/* Sections */
.how-it-works,
.unit-preview {
    padding: 3rem 0;
}

.how-it-works h2,
.unit-preview h2,
.intro-section h1,
.units-section h1 {
    text-align: center;
    margin-bottom: 2rem;
    font-size: 2rem;
    color: var(--primary-color);
}

/* Unit Cards */
.unit-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.unit-card {
    background: white;
    padding: 1.5rem;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
}

.unit-card h3 {
    color: var(--secondary-color);
    margin-bottom: 0.5rem;
}

.unit-card p {
    font-size: 0.95rem;
    margin-bottom: 0.5rem;
}

.unit-card small {
    color: #7f8c8d;
    display: block;
    margin-top: 0.5rem;
}

/* Units Page */
.units-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 2rem;
}

.unit-card-large {
    background: white;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    overflow: hidden;
    transition: transform 0.3s ease;
}

.unit-card-large:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.15);
}

.unit-header {
    background: linear-gradient(135deg, var(--secondary-color) 0%, #2980b9 100%);
    color: white;
    padding: 1.5rem;
}

.unit-header h2 {
    margin: 0;
    font-size: 1.3rem;
}

.unit-title {
    margin: 0.5rem 0 0 0;
    font-size: 1.1rem;
    opacity: 0.95;
}

.unit-body {
    padding: 1.5rem;
}

.unit-description {
    color: #555;
    margin-bottom: 1rem;
}

.lessons-list h3 {
    margin-bottom: 1rem;
    color: var(--primary-color);
    font-size: 0.95rem;
}

.lesson-item {
    display: flex;
    gap: 0.5rem;
    padding: 0.5rem;
    background: #f9f9f9;
    border-radius: 4px;
    margin-bottom: 0.5rem;
    font-size: 0.9rem;
}

.lesson-code {
    background: var(--secondary-color);
    color: white;
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    font-weight: bold;
    min-width: 50px;
    text-align: center;
}

.lesson-title {
    flex: 1;
    color: var(--dark-text);
}

.frame-count {
    color: #7f8c8d;
    font-size: 0.85rem;
}

.unit-footer {
    padding: 1.5rem;
    border-top: 1px solid #eee;
    text-align: center;
}

/* Lessons Section */
.lessons-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 2rem;
    margin: 2rem 0;
}

.lesson-card {
    background: white;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    overflow: hidden;
    transition: transform 0.3s ease;
}

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

.lesson-header {
    background: var(--secondary-color);
    color: white;
    padding: 1.5rem;
}

.lesson-header h2 {
    margin: 0;
    font-size: 1.1rem;
}

.lesson-content {
    padding: 1.5rem;
}

.lesson-content p {
    margin-bottom: 1rem;
    color: #555;
}

.lesson-footer {
    padding: 1.5rem;
    border-top: 1px solid #eee;
    text-align: center;
}

/* Progress Bar */
.progress-bar {
    width: 100%;
    height: 8px;
    background: #e0e0e0;
    border-radius: 4px;
    overflow: hidden;
    margin: 1rem 0;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--secondary-color) 0%, var(--success-color) 100%);
    transition: width 0.3s ease;
}

.progress-text {
    text-align: center;
    color: #7f8c8d;
    font-size: 0.9rem;
    margin-top: 0.5rem;
}

/* Frame Section */
.frame-section {
    background: white;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    padding: 2rem;
    margin: 2rem 0;
}

.breadcrumb {
    color: #7f8c8d;
    margin-bottom: 1.5rem;
    font-size: 0.9rem;
}

.breadcrumb a {
    color: var(--secondary-color);
    text-decoration: none;
}

.breadcrumb span {
    margin: 0 0.5rem;
}

.frame-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 2rem;
}

.unit-lesson {
    color: var(--secondary-color);
    margin-bottom: 0.5rem;
    font-size: 0.9rem;
}

.frame-header h1 {
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.badge {
    background: var(--secondary-color);
    color: white;
    padding: 0.5rem 1rem;
    border-radius: var(--border-radius);
    font-size: 0.9rem;
    white-space: nowrap;
}

.frame-content {
    margin: 2rem 0;
}

.image-section {
    margin-bottom: 2rem;
    text-align: center;
}

.frame-image {
    max-width: 100%;
    height: auto;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    max-height: 400px;
}

.reading-section,
.key-idea-section,
.activity-section {
    margin-bottom: 2rem;
}

.reading-section h2,
.key-idea-section h2,
.activity-section h2 {
    color: var(--primary-color);
    margin-bottom: 1rem;
    font-size: 1.3rem;
}

.reading-box,
.key-idea-box {
    background: var(--light-bg);
    padding: 1.5rem;
    border-left: 4px solid var(--secondary-color);
    border-radius: 4px;
    line-height: 1.8;
}

.activity-box {
    background: white;
    border: 2px solid var(--light-bg);
    padding: 1.5rem;
    border-radius: var(--border-radius);
}

.question {
    margin-bottom: 1.5rem;
}

.question p {
    font-size: 1.1rem;
    color: var(--dark-text);
}

.options {
    margin: 1.5rem 0;
}

.option-label {
    display: flex;
    align-items: center;
    padding: 0.75rem;
    margin-bottom: 0.75rem;
    background: white;
    border: 2px solid #e0e0e0;
    border-radius: 4px;
    cursor: pointer;
    transition: all 0.3s ease;
}

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

.option-input {
    margin-right: 1rem;
    cursor: pointer;
    width: 18px;
    height: 18px;
}

.option-text {
    flex: 1;
}

/* Word Bank */
.word-bank {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    margin: 1.5rem 0;
}

.word-btn {
    padding: 0.5rem 1rem;
    background: white;
    border: 2px solid var(--secondary-color);
    color: var(--secondary-color);
    border-radius: 4px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-weight: 500;
}

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

.word-btn.selected {
    background: var(--secondary-color);
    color: white;
}

/* Feedback Box */
.feedback-box {
    margin-top: 1.5rem;
    padding: 1.5rem;
    border-radius: var(--border-radius);
    background: var(--light-bg);
    border-left: 4px solid var(--success-color);
}

.feedback-box.incorrect {
    border-left-color: var(--accent-color);
}

.feedback-box p {
    margin: 0;
}

/* Frame Navigation */
.frame-navigation {
    display: flex;
    gap: 1rem;
    margin-top: 2rem;
    justify-content: space-between;
    flex-wrap: wrap;
}

.frame-navigation .btn {
    flex: 1;
    text-align: center;
    min-width: 150px;
}

/* Intro Section */
.intro-section {
    background: white;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    padding: 2rem;
    margin: 2rem 0;
}

.intro-content h2 {
    color: var(--primary-color);
    margin-top: 2rem;
    margin-bottom: 1rem;
    font-size: 1.3rem;
}

.intro-content h2:first-of-type {
    margin-top: 0;
}

.intro-list {
    list-style-position: inside;
    margin-bottom: 1rem;
    line-height: 2;
    color: #555;
}

.intro-list li {
    margin-bottom: 0.5rem;
}

/* Certificate Section */
.certificate-section {
    background: white;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    padding: 2rem;
    margin: 2rem 0;
}

.certificate-form {
    background: var(--light-bg);
    padding: 2rem;
    border-radius: var(--border-radius);
    margin: 2rem 0;
}

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

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

.form-input {
    width: 100%;
    padding: 0.75rem;
    border: 2px solid #e0e0e0;
    border-radius: 4px;
    font-size: 1rem;
    transition: border-color 0.3s ease;
}

.form-input:focus {
    outline: none;
    border-color: var(--secondary-color);
}

.certificate-box {
    margin: 2rem 0;
}

.certificate-content {
    background: white;
    border: 3px double var(--primary-color);
    padding: 3rem;
    text-align: center;
    margin-bottom: 2rem;
}

.certificate-border {
    border: 2px solid var(--secondary-color);
    padding: 2rem;
    border-radius: var(--border-radius);
}

.certificate-title {
    font-size: 2rem;
    color: var(--primary-color);
    margin-bottom: 2rem;
    text-transform: uppercase;
    letter-spacing: 2px;
}

.certificate-text {
    font-size: 1rem;
    margin: 1rem 0;
    color: var(--dark-text);
}

.student-name {
    font-size: 1.8rem;
    font-weight: bold;
    color: var(--secondary-color);
    text-decoration: underline;
    margin: 2rem 0;
}

.course-name {
    font-size: 1.4rem;
    color: var(--primary-color);
    margin: 1rem 0;
}

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

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

.certificate-info h2 {
    color: var(--primary-color);
    margin-bottom: 1rem;
}

/* Center Button */
.center-button {
    text-align: center;
    margin: 2rem 0;
}

/* Responsive */
@media (max-width: 768px) {
    .nav-menu {
        gap: 1rem;
    }

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

    .hero .subtitle {
        font-size: 1.2rem;
    }

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

    .cta-buttons .btn {
        width: 100%;
    }

    .frame-header {
        flex-direction: column;
        gap: 1rem;
    }

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

    .frame-navigation .btn {
        width: 100%;
    }

    .units-grid,
    .lessons-grid {
        grid-template-columns: 1fr;
    }

    .certificate-content {
        padding: 1.5rem;
    }

    .certificate-title {
        font-size: 1.5rem;
    }

    .student-name {
        font-size: 1.3rem;
    }
}

/* About Section */
.about-section {
    background: white;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    padding: 2rem;
    margin: 2rem 0;
}

.about-header {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    margin-bottom: 3rem;
    align-items: center;
}

.about-image {
    max-width: 100%;
    height: auto;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
}

.about-text h1 {
    color: var(--primary-color);
    margin-bottom: 1rem;
    font-size: 2rem;
}

.about-subtitle {
    color: #555;
    line-height: 1.8;
    font-size: 1.05rem;
}

.about-content h2 {
    color: var(--primary-color);
    margin-top: 2rem;
    margin-bottom: 1rem;
    font-size: 1.5rem;
}

.about-content p {
    margin-bottom: 1rem;
    color: #555;
    line-height: 1.8;
}

.roles-section {
    margin: 2rem 0;
}

.roles-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    margin: 1.5rem 0;
}

.role-card {
    background: var(--light-bg);
    padding: 1.5rem;
    border-radius: var(--border-radius);
    border-left: 4px solid var(--secondary-color);
}

.role-card h4 {
    color: var(--secondary-color);
    margin-bottom: 0.5rem;
}

.role-card p {
    color: #666;
    font-size: 0.95rem;
}

.vision-section {
    background: linear-gradient(135deg, var(--light-bg) 0%, #f9f9f9 100%);
    padding: 2rem;
    border-radius: var(--border-radius);
    margin: 2rem 0;
    border-left: 4px solid var(--secondary-color);
}

.vision-section p {
    margin: 0;
    font-size: 1.05rem;
}

.contact-section {
    background: white;
    border: 2px solid var(--light-bg);
    padding: 2rem;
    border-radius: var(--border-radius);
    margin: 2rem 0;
}

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

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

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

.info-list a {
    color: var(--secondary-color);
    text-decoration: none;
}

.info-list a:hover {
    text-decoration: underline;
}

@media (max-width: 768px) {
    .about-header {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }

    .about-text h1 {
        font-size: 1.5rem;
    }

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

@media print {
    body {
        background: white;
    }

    header,
    footer,
    .certificate-form,
    .certificate-actions,
    .certificate-info {
        display: none;
    }

    .certificate-box {
        box-shadow: none;
    }

    .certificate-content {
        border: none;
        page-break-after: avoid;
    }
}