/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #6366f1;
    --primary-dark: #4f46e5;
    --secondary-color: #f59e0b;
    --accent-color: #10b981;
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --text-light: #9ca3af;
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --bg-dark: #111827;
    --border-color: #e5e7eb;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
    --border-radius: 8px;
    --border-radius-lg: 12px;
    --transition: all 0.3s ease;
}

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

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.2;
    margin-bottom: 1rem;
}

h1 { font-size: 3rem; }
h2 { font-size: 2.5rem; }
h3 { font-size: 2rem; }
h4 { font-size: 1.5rem; }
h5 { font-size: 1.25rem; }
h6 { font-size: 1rem; }

p {
    margin-bottom: 1rem;
    color: var(--text-secondary);
}

.section-title {
    text-align: center;
    margin-bottom: 3rem;
    position: relative;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 3px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    border-radius: 2px;
}

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

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: white;
    box-shadow: var(--shadow-md);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

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

.btn-secondary:hover {
    background: var(--primary-color);
    color: white;
    transform: translateY(-2px);
}

/* Header */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
    transition: var(--transition);
}

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

.nav-brand {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

.nav-brand i {
    font-size: 2rem;
}

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

.nav-link {
    text-decoration: none;
    color: var(--text-primary);
    font-weight: 500;
    transition: var(--transition);
    position: relative;
}

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

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-color);
    transition: var(--transition);
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}

.nav-toggle {
    display: none;
    flex-direction: column;
    cursor: pointer;
    gap: 4px;
}

.nav-toggle span {
    width: 25px;
    height: 3px;
    background: var(--text-primary);
    transition: var(--transition);
}

/* Hero Section */
.hero {
    padding: 8rem 2rem 4rem;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="grain" width="100" height="100" patternUnits="userSpaceOnUse"><circle cx="25" cy="25" r="1" fill="white" opacity="0.1"/><circle cx="75" cy="75" r="1" fill="white" opacity="0.1"/><circle cx="50" cy="10" r="1" fill="white" opacity="0.1"/><circle cx="10" cy="90" r="1" fill="white" opacity="0.1"/></pattern></defs><rect width="100" height="100" fill="url(%23grain)"/></svg>');
    opacity: 0.3;
}

.hero-content {
    position: relative;
    z-index: 2;
    max-width: 800px;
    margin: 0 auto;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    background: linear-gradient(45deg, #fff, #f0f9ff);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.25rem;
    margin-bottom: 2rem;
    color: rgba(255, 255, 255, 0.9);
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    margin-bottom: 4rem;
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: 4rem;
    margin-top: 4rem;
}

.stat {
    text-align: center;
}

.stat-number {
    display: block;
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--secondary-color);
}

.stat-label {
    font-size: 1rem;
    color: rgba(255, 255, 255, 0.8);
}

/* Features Section */
.features {
    padding: 6rem 0;
    background: var(--bg-secondary);
}

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

.feature-card {
    background: white;
    padding: 2rem;
    border-radius: var(--border-radius-lg);
    text-align: center;
    box-shadow: var(--shadow-md);
    transition: var(--transition);
}

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

.feature-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 1.5rem;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 2rem;
}

.feature-card h3 {
    margin-bottom: 1rem;
    color: var(--text-primary);
}

/* Courses Section */
.courses {
    padding: 6rem 0;
}

.course-filters {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 3rem;
    flex-wrap: wrap;
}

.filter-btn {
    padding: 0.5rem 1rem;
    border: 2px solid var(--border-color);
    background: white;
    color: var(--text-secondary);
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: var(--transition);
    font-weight: 500;
}

.filter-btn:hover,
.filter-btn.active {
    border-color: var(--primary-color);
    background: var(--primary-color);
    color: white;
}

.courses-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
}

.course-card {
    background: white;
    border-radius: var(--border-radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-md);
    transition: var(--transition);
    cursor: pointer;
}

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

.course-image {
    height: 200px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 3rem;
}

.course-content {
    padding: 1.5rem;
}

.course-category {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    background: var(--bg-secondary);
    color: var(--primary-color);
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 500;
    margin-bottom: 1rem;
}

.course-title {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.course-description {
    color: var(--text-secondary);
    margin-bottom: 1rem;
    font-size: 0.9rem;
}

.course-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 1rem;
    border-top: 1px solid var(--border-color);
}

.course-duration {
    color: var(--text-light);
    font-size: 0.875rem;
}

.course-level {
    padding: 0.25rem 0.5rem;
    background: var(--accent-color);
    color: white;
    border-radius: 4px;
    font-size: 0.75rem;
    font-weight: 500;
}

/* About Section */
.about {
    padding: 6rem 0;
    background: var(--bg-secondary);
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.about-text h2 {
    text-align: left;
    margin-bottom: 2rem;
}

.about-text h2::after {
    left: 0;
    transform: none;
}

.about-features {
    margin-top: 2rem;
}

.about-feature {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 1rem;
}

.about-feature i {
    color: var(--accent-color);
    font-size: 1.25rem;
}

.about-image {
    display: flex;
    justify-content: center;
    align-items: center;
}

.about-placeholder {
    width: 300px;
    height: 300px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 6rem;
}

/* Contact Section */
.contact {
    padding: 6rem 0;
}

.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.contact-item i {
    width: 50px;
    height: 50px;
    background: var(--primary-color);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
}

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

.contact-form input,
.contact-form textarea {
    padding: 1rem;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    font-family: inherit;
    transition: var(--transition);
}

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

/* Footer */
.footer {
    background: var(--bg-dark);
    color: white;
    padding: 2rem 0;
    text-align: center;
}

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

.footer-brand {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.25rem;
    font-weight: 600;
}

.footer-social {
    display: flex;
    gap: 1rem;
}

.footer-social a {
    width: 40px;
    height: 40px;
    background: var(--primary-color);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    text-decoration: none;
    transition: var(--transition);
}

.footer-social a:hover {
    background: var(--secondary-color);
    transform: translateY(-2px);
}

/* Course Detail Styles */
.course-detail {
    max-width: 800px;
    margin: 0 auto;
    padding: 2rem;
    background: white;
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-lg);
}

.course-header {
    text-align: center;
    margin-bottom: 3rem;
    padding-bottom: 2rem;
    border-bottom: 2px solid var(--border-color);
}

.course-syllabus {
    margin-bottom: 3rem;
}

.syllabus-item {
    background: var(--bg-secondary);
    margin-bottom: 1rem;
    border-radius: var(--border-radius);
    overflow: hidden;
}

.syllabus-header {
    padding: 1rem;
    background: white;
    border-left: 4px solid var(--primary-color);
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: var(--transition);
}

.syllabus-header:hover {
    background: var(--bg-secondary);
}

.syllabus-content {
    padding: 0 1rem;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease;
}

.syllabus-content.active {
    max-height: 500px;
    padding: 1rem;
}

.lesson-item {
    padding: 0.5rem 0;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.lesson-item:last-child {
    border-bottom: none;
}

.lesson-status {
    width: 20px;
    height: 20px;
    border: 2px solid var(--border-color);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
}

.lesson-status.completed {
    background: var(--accent-color);
    border-color: var(--accent-color);
    color: white;
}

/* Interactive Elements */
.quiz-container {
    background: var(--bg-secondary);
    padding: 2rem;
    border-radius: var(--border-radius-lg);
    margin: 2rem 0;
}

.quiz-question {
    margin-bottom: 1.5rem;
}

.quiz-options {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.quiz-option {
    padding: 1rem;
    background: white;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: var(--transition);
}

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

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

.progress-bar {
    width: 100%;
    height: 8px;
    background: var(--border-color);
    border-radius: 4px;
    overflow: hidden;
    margin: 1rem 0;
}

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

/* Responsive Design */
@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: 100%;
        left: 0;
        right: 0;
        background: white;
        flex-direction: column;
        padding: 2rem;
        box-shadow: var(--shadow-lg);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: var(--transition);
    }

    .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }

    .nav-toggle {
        display: flex;
    }

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

    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }

    .hero-stats {
        gap: 2rem;
    }

    .about-content,
    .contact-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .footer-content {
        flex-direction: column;
        gap: 1rem;
    }

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

    .course-filters {
        justify-content: flex-start;
        overflow-x: auto;
        padding-bottom: 1rem;
    }

    h1 { font-size: 2rem; }
    h2 { font-size: 1.75rem; }
    h3 { font-size: 1.5rem; }
}

@media (max-width: 480px) {
    .container {
        padding: 0 0.5rem;
    }

    .nav {
        padding: 1rem;
    }

    .hero {
        padding: 6rem 1rem 3rem;
    }

    .hero-stats {
        flex-direction: column;
        gap: 1rem;
    }

    .features,
    .courses,
    .about,
    .contact {
        padding: 3rem 0;
    }
}

/* Animation Classes */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

.slide-in-left {
    opacity: 0;
    transform: translateX(-50px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.slide-in-left.visible {
    opacity: 1;
    transform: translateX(0);
}

.slide-in-right {
    opacity: 0;
    transform: translateX(50px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.slide-in-right.visible {
    opacity: 1;
    transform: translateX(0);
}

/* Course Page Specific Styles */
.course-content-tabs {
    margin: 3rem 0;
}

.tab-buttons {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
    border-bottom: 2px solid var(--border-color);
    flex-wrap: wrap;
}

.tab-btn {
    padding: 1rem 1.5rem;
    background: none;
    border: none;
    color: var(--text-secondary);
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    border-bottom: 3px solid transparent;
}

.tab-btn:hover,
.tab-btn.active {
    color: var(--primary-color);
    border-bottom-color: var(--primary-color);
}

.tab-content {
    display: none;
    animation: fadeIn 0.3s ease;
}

.tab-content.active {
    display: block;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.meta-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-secondary);
}

.meta-item i {
    color: var(--primary-color);
}

.progress-section {
    margin: 2rem 0;
    padding: 2rem;
    background: var(--bg-secondary);
    border-radius: var(--border-radius-lg);
}

.progress-section h3 {
    margin-bottom: 1rem;
    text-align: center;
}

.module-info {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.module-duration {
    color: var(--text-light);
    font-size: 0.875rem;
    padding: 0.25rem 0.75rem;
    background: var(--bg-secondary);
    border-radius: 20px;
}

.module-description {
    color: var(--text-secondary);
    font-style: italic;
    margin-bottom: 1rem;
    padding: 1rem;
    background: var(--bg-secondary);
    border-radius: var(--border-radius);
}

.lesson-meta {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.lesson-duration {
    color: var(--text-light);
    font-size: 0.875rem;
}

/* Course Overview Styles */
.learning-objectives {
    list-style: none;
    padding: 0;
}

.learning-objectives li {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 0.75rem;
    padding: 0.5rem;
    background: var(--bg-secondary);
    border-radius: var(--border-radius);
}

.learning-objectives i {
    color: var(--accent-color);
    font-size: 1.25rem;
}

.overview-section {
    margin-bottom: 3rem;
}

.overview-section h4 {
    color: var(--primary-color);
    margin-bottom: 1.5rem;
}

.structure-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    margin-top: 2rem;
}

.structure-item {
    text-align: center;
    padding: 2rem;
    background: white;
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-md);
    transition: var(--transition);
}

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

.structure-item i {
    font-size: 3rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.structure-item h5 {
    margin-bottom: 1rem;
    color: var(--text-primary);
}

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

.path-step {
    display: flex;
    align-items: center;
    gap: 1.5rem;
    padding: 1.5rem;
    background: white;
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.path-step:hover {
    box-shadow: var(--shadow-md);
}

.step-number {
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.25rem;
    flex-shrink: 0;
}

.step-content h5 {
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.step-content p {
    margin: 0;
    color: var(--text-secondary);
}

/* Project Styles */
.project-card {
    background: white;
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-md);
    margin-bottom: 2rem;
    overflow: hidden;
    transition: var(--transition);
}

.project-card:hover {
    box-shadow: var(--shadow-lg);
}

.project-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.5rem;
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
}

.project-header h4 {
    margin: 0;
    color: var(--text-primary);
}

.project-difficulty {
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 500;
}

.project-difficulty {
    background: var(--accent-color);
    color: white;
}

.project-content {
    padding: 1.5rem;
}

.project-content ul {
    margin: 1rem 0;
    padding-left: 1.5rem;
}

.project-content li {
    margin-bottom: 0.5rem;
    color: var(--text-secondary);
}

.project-demo {
    margin-top: 2rem;
    padding: 1.5rem;
    background: var(--bg-secondary);
    border-radius: var(--border-radius);
}

.project-demo h5 {
    margin-bottom: 1rem;
    color: var(--primary-color);
}

/* Calculator Demo Styles */
.calculator-demo {
    max-width: 300px;
    margin: 0 auto;
    background: #333;
    border-radius: var(--border-radius-lg);
    padding: 1rem;
    box-shadow: var(--shadow-lg);
}

.calc-display {
    margin-bottom: 1rem;
}

.calc-display input {
    width: 100%;
    padding: 1rem;
    font-size: 1.5rem;
    text-align: right;
    border: none;
    border-radius: var(--border-radius);
    background: #222;
    color: white;
    font-family: 'Courier New', monospace;
}

.calc-buttons {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 0.5rem;
}

.calc-buttons button {
    padding: 1rem;
    border: none;
    border-radius: var(--border-radius);
    font-size: 1.25rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    background: #666;
    color: white;
}

.calc-buttons button:hover {
    background: #777;
    transform: translateY(-2px);
}

.calc-buttons button:active {
    transform: translateY(0);
}

.calc-equals {
    background: var(--primary-color) !important;
    grid-row: span 2;
}

.calc-zero {
    grid-column: span 2;
}

/* Button Enhancements */
.btn-large {
    padding: 1rem 2rem;
    font-size: 1.125rem;
}

.course-actions {
    display: flex;
    gap: 1rem;
    margin-top: 3rem;
    padding-top: 2rem;
    border-top: 2px solid var(--border-color);
    flex-wrap: wrap;
}

/* Quiz Results Styles */
.quiz-results {
    text-align: center;
    padding: 2rem;
}

.score-display {
    margin: 2rem 0;
}

.score-circle {
    width: 150px;
    height: 150px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1rem;
    box-shadow: var(--shadow-lg);
}

.score-percentage {
    font-size: 2.5rem;
    font-weight: 700;
    color: white;
}

/* Responsive Design for Course Pages */
@media (max-width: 768px) {
    .course-meta {
        grid-template-columns: 1fr;
        gap: 1rem;
    }
    
    .tab-buttons {
        justify-content: flex-start;
        overflow-x: auto;
        padding-bottom: 1rem;
    }
    
    .structure-grid {
        grid-template-columns: 1fr;
    }
    
    .path-step {
        flex-direction: column;
        text-align: center;
    }
    
    .project-header {
        flex-direction: column;
        gap: 1rem;
        align-items: flex-start;
    }
    
    .course-actions {
        flex-direction: column;
    }
    
    .calc-buttons {
        grid-template-columns: repeat(4, 1fr);
        gap: 0.25rem;
    }
    
    .calc-buttons button {
        padding: 0.75rem;
        font-size: 1rem;
    }
}

@media (max-width: 480px) {
    .calculator-demo {
        max-width: 100%;
    }
    
    .score-circle {
        width: 120px;
        height: 120px;
    }
    
    .score-percentage {
        font-size: 2rem;
    }
}