:root {
    --primary-color: #007bff;
    --secondary-color: #6c757d;
    --success-color: #28a745;
    --info-color: #17a2b8;
    --warning-color: #ffc107;
    --danger-color: #dc3545;
    --light-color: #f8f9fa;
    --dark-color: #343a40;
    
    --beginner-color: #28a745;
    --intermediate-color: #ffc107;
    --advanced-color: #dc3545;
    
    --border-radius: 8px;
    --box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    --transition: all 0.3s ease;
}

/* Global Styles */
body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f8f9fa;
}

.main-content {
    margin-top: 76px; /* Account for fixed navbar */
    min-height: calc(100vh - 76px);
}

/* Typography */
.section-title {
    font-size: 2rem;
    font-weight: 600;
    color: var(--dark-color);
    margin-bottom: 0.5rem;
}

.section-subtitle {
    color: var(--secondary-color);
    font-size: 1.1rem;
    margin-bottom: 2rem;
}

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

.page-subtitle {
    color: var(--secondary-color);
    font-size: 1.2rem;
    margin-bottom: 2rem;
}

/* Hero Section */
.hero-section {
    background: linear-gradient(135deg, var(--primary-color), #0056b3);
    color: white;
    padding: 4rem 2rem;
    border-radius: var(--border-radius);
    margin-bottom: 3rem;
}

.hero-stats {
    margin-top: 2rem;
}

.stat-item {
    padding: 1rem;
}

.stat-number {
    font-size: 2.5rem;
    font-weight: 700;
    margin: 0;
    color: white;
}

.stat-label {
    margin: 0;
    opacity: 0.9;
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 1px;
}

/* Learning Path */
.learning-path {
    position: relative;
}

.path-item {
    display: flex;
    align-items: flex-start;
    margin-bottom: 2rem;
    position: relative;
}

.path-item::before {
    content: '';
    position: absolute;
    left: 20px;
    top: 60px;
    bottom: -20px;
    width: 2px;
    background: #e9ecef;
    z-index: 1;
}

.path-item:last-child::before {
    display: none;
}

.path-number {
    width: 40px;
    height: 40px;
    background: var(--primary-color);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    margin-right: 1.5rem;
    position: relative;
    z-index: 2;
    flex-shrink: 0;
}

.path-content {
    flex: 1;
}

/* Cards */
.tutorial-card, .project-card {
    border: none;
    box-shadow: var(--box-shadow);
    transition: var(--transition);
    border-radius: var(--border-radius);
}

.tutorial-card:hover, .project-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 20px rgba(0,0,0,0.15);
}

.tutorial-progress {
    position: relative;
}

.progress-circle {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 12px;
    font-weight: 600;
}

.progress-circle.completed {
    background: var(--success-color);
    color: white;
}

.progress-circle.in-progress {
    background: var(--warning-color);
    color: white;
}

.progress-circle.not-started {
    background: var(--light-color);
    color: var(--secondary-color);
    border: 2px solid #dee2e6;
}

/* Difficulty Badges */
.bg-beginner { background-color: var(--beginner-color) !important; }
.bg-intermediate { background-color: var(--warning-color) !important; }
.bg-advanced { background-color: var(--danger-color) !important; }

/* Project Cards */
.project-icon {
    width: 60px;
    height: 60px;
    background: var(--primary-color);
    border-radius: var(--border-radius);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
}

.project-icon i {
    width: 30px;
    height: 30px;
}

.project-meta {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 0.5rem;
}

/* Features Section */
.features-section {
    background: white;
    padding: 3rem 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    margin-top: 3rem;
}

.feature-item {
    padding: 2rem 1rem;
}

.feature-icon {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, var(--primary-color), #0056b3);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1.5rem;
    color: white;
}

.feature-icon i {
    width: 32px;
    height: 32px;
}

/* Tutorial Page Styles */
.tutorial-sidebar {
    background: white;
    padding: 1.5rem;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    top: 100px;
}

.tutorial-nav .nav-link {
    border-radius: var(--border-radius);
    color: var(--dark-color);
    padding: 0.75rem 1rem;
    margin-bottom: 0.25rem;
    display: flex;
    align-items: center;
    transition: var(--transition);
}

.tutorial-nav .nav-link:hover {
    background-color: var(--light-color);
}

.tutorial-nav .nav-link.active {
    background-color: var(--primary-color);
    color: white;
}

.step-number {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 24px;
    height: 24px;
    background: var(--light-color);
    border-radius: 50%;
    font-size: 12px;
    font-weight: 600;
    margin-right: 0.75rem;
    color: var(--secondary-color);
}

.tutorial-nav .nav-link.active .step-number {
    background: rgba(255,255,255,0.2);
    color: white;
}

/* Tutorial Content */
.tutorial-header {
    background: white;
    padding: 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
}

.tutorial-title {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--dark-color);
    margin-bottom: 1rem;
}

.tutorial-meta {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
    margin-bottom: 1rem;
}

.tutorial-step {
    background: white;
    padding: 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    margin-bottom: 2rem;
    display: none;
}

.tutorial-step.active {
    display: block;
}

.step-header {
    display: flex;
    justify-content: between;
    align-items: center;
    margin-bottom: 1.5rem;
}

.step-title {
    font-size: 1.8rem;
    font-weight: 600;
    color: var(--dark-color);
    display: flex;
    align-items: center;
    flex: 1;
}

.step-number-badge {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    background: var(--primary-color);
    color: white;
    border-radius: 50%;
    font-size: 14px;
    font-weight: 600;
    margin-right: 1rem;
}

.step-time {
    color: var(--secondary-color);
    font-size: 0.9rem;
}

.step-content {
    font-size: 1.1rem;
    line-height: 1.8;
}

.step-content h3 {
    color: var(--dark-color);
    margin-top: 2rem;
    margin-bottom: 1rem;
}

.step-content h4 {
    color: var(--dark-color);
    margin-top: 1.5rem;
    margin-bottom: 0.75rem;
}

.code-example {
    background: #f8f9fa;
    border: 1px solid #e9ecef;
    border-radius: var(--border-radius);
    padding: 1.5rem;
}

.code-example pre {
    margin: 0;
    font-size: 0.9rem;
}

.interactive-demo {
    border: 2px dashed #dee2e6;
    border-radius: var(--border-radius);
    padding: 1.5rem;
    background: #f8f9fa;
}

.demo-container {
    background: white;
    padding: 1rem;
    border-radius: var(--border-radius);
    border: 1px solid #dee2e6;
    min-height: 200px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--secondary-color);
}

/* Project Page Styles */
.project-info-card {
    top: 100px;
}

.project-info-card .large-icon {
    width: 48px;
    height: 48px;
}

.detail-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.5rem 0;
    border-bottom: 1px solid #f1f3f4;
}

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

.project-content {
    background: white;
    padding: 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
}

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

.project-section h2 {
    color: var(--dark-color);
    font-weight: 600;
    margin-bottom: 1.5rem;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid var(--primary-color);
}

.project-steps {
    margin-top: 2rem;
}

.project-step {
    background: #f8f9fa;
    border-radius: var(--border-radius);
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    border-left: 4px solid var(--primary-color);
}

.project-step .step-header h4 {
    color: var(--dark-color);
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
}

.project-step .step-number {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 28px;
    height: 28px;
    background: var(--primary-color);
    color: white;
    border-radius: 50%;
    font-size: 12px;
    font-weight: 600;
    margin-right: 1rem;
}

.code-block {
    background: #2d3748;
    color: #e2e8f0;
    border-radius: var(--border-radius);
    padding: 1.5rem;
    overflow-x: auto;
}

.code-block pre {
    margin: 0;
    font-family: 'Monaco', 'Menlo', monospace;
    font-size: 0.9rem;
}

/* Progress Page Styles */
.stats-card {
    border: none;
    box-shadow: var(--box-shadow);
    transition: var(--transition);
    border-radius: var(--border-radius);
}

.stats-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 20px rgba(0,0,0,0.15);
}

.stats-icon {
    width: 60px;
    height: 60px;
    background: var(--primary-color);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1rem;
    color: white;
}

.stats-number {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary-color);
    margin: 0;
}

.stats-label {
    color: var(--secondary-color);
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    margin: 0;
}

.progress-timeline {
    position: relative;
}

.progress-item {
    display: flex;
    align-items: flex-start;
    margin-bottom: 2rem;
    position: relative;
}

.progress-item::before {
    content: '';
    position: absolute;
    left: 20px;
    top: 60px;
    bottom: -20px;
    width: 2px;
    background: #e9ecef;
    z-index: 1;
}

.progress-item:last-child::before {
    display: none;
}

.progress-marker {
    margin-right: 1.5rem;
    position: relative;
    z-index: 2;
}

.marker {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 12px;
    font-weight: 600;
}

.marker.completed {
    background: var(--success-color);
    color: white;
}

.marker.in-progress {
    background: var(--warning-color);
    color: white;
}

.marker.not-started {
    background: var(--light-color);
    color: var(--secondary-color);
    border: 2px solid #dee2e6;
}

.progress-content {
    flex: 1;
}

.progress-actions {
    display: flex;
    gap: 0.5rem;
}

.tutorial-progress {
    margin-top: 1rem;
}

.tutorial-progress .progress {
    height: 6px;
    margin-bottom: 0.5rem;
}

/* Responsive Design */
@media (max-width: 768px) {
    .main-content {
        margin-top: 60px;
    }
    
    .hero-section {
        padding: 2rem 1rem;
    }
    
    .stat-number {
        font-size: 2rem;
    }
    
    .section-title {
        font-size: 1.75rem;
    }
    
    .page-title {
        font-size: 2rem;
    }
    
    .tutorial-sidebar {
        position: static !important;
        margin-bottom: 2rem;
    }
    
    .path-item {
        flex-direction: column;
        align-items: center;
        text-align: center;
    }
    
    .path-item::before {
        display: none;
    }
    
    .path-number {
        margin-bottom: 1rem;
    }
    
    .tutorial-meta, .project-meta {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.5rem;
    }
}

/* Animation Classes */
.fade-in {
    animation: fadeIn 0.5s ease-in;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

.slide-in-left {
    animation: slideInLeft 0.5s ease-out;
}

@keyframes slideInLeft {
    from { opacity: 0; transform: translateX(-30px); }
    to { opacity: 1; transform: translateX(0); }
}

/* Utility Classes */
.text-gradient {
    background: linear-gradient(135deg, var(--primary-color), #0056b3);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.border-gradient {
    border: 2px solid;
    border-image: linear-gradient(135deg, var(--primary-color), #0056b3) 1;
}

/* Dark mode support */
@media (prefers-color-scheme: dark) {
    :root {
        --light-color: #343a40;
        --dark-color: #f8f9fa;
    }
    
    body {
        background-color: #1a1a1a;
        color: #f8f9fa;
    }
    
    .tutorial-sidebar,
    .tutorial-header,
    .tutorial-step,
    .project-content,
    .features-section {
        background: #2d3748;
        color: #f8f9fa;
    }
    
    .card {
        background: #2d3748;
        color: #f8f9fa;
        border-color: #4a5568;
    }
}