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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: #333;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
}

header {
    text-align: center;
    padding: 2rem 0;
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    color: white;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
    font-weight: 300;
}

header p {
    font-size: 1.1rem;
    opacity: 0.9;
}

/* Navigation */
.main-nav {
    display: flex;
    justify-content: center;
    gap: 1rem;
    padding: 1.5rem;
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    flex-wrap: wrap;
}

.nav-btn {
    padding: 0.8rem 1.5rem;
    border: none;
    background: rgba(255, 255, 255, 0.2);
    color: white;
    border-radius: 25px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-weight: 500;
    border: 2px solid transparent;
}

.nav-btn:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: translateY(-2px);
}

.nav-btn.active {
    background: white;
    color: #333;
    border-color: #667eea;
}

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

.content-section {
    display: none;
    background: white;
    border-radius: 15px;
    padding: 2rem;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    animation: fadeIn 0.5s ease-in;
}

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

.content-section h2 {
    color: #333;
    margin-bottom: 1.5rem;
    text-align: center;
    font-size: 2rem;
    font-weight: 300;
}

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

/* Architecture Section */
.concept-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.concept-card {
    background: #f8f9fa;
    border-radius: 10px;
    padding: 1.5rem;
    border-left: 4px solid #667eea;
    transition: transform 0.3s ease;
}

.concept-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.1);
}

.concept-card h3 {
    color: #333;
    margin-bottom: 0.5rem;
    font-size: 1.3rem;
}

.concept-card p {
    color: #666;
    margin-bottom: 1rem;
}

/* Architecture Demo Styles */
.architecture-demo {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.layer {
    padding: 0.8rem;
    border-radius: 5px;
    text-align: center;
    font-weight: 500;
    color: white;
}

.layer.presentation { background: #e74c3c; }
.layer.business { background: #f39c12; }
.layer.data { background: #27ae60; }
.layer.database { background: #3498db; }

.microservices-demo {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 0.5rem;
}

.service {
    padding: 0.8rem;
    background: #667eea;
    color: white;
    border-radius: 5px;
    text-align: center;
    font-size: 0.9rem;
}

.mvc-demo {
    display: flex;
    justify-content: space-around;
    gap: 0.5rem;
}

.mvc-component {
    flex: 1;
    padding: 1rem;
    border-radius: 8px;
    text-align: center;
    color: white;
    font-weight: 500;
}

.mvc-component.model { background: #e67e22; }
.mvc-component.view { background: #8e44ad; }
.mvc-component.controller { background: #16a085; }

.mvc-component small {
    display: block;
    font-size: 0.8rem;
    opacity: 0.8;
    margin-top: 0.3rem;
}

/* Code Examples */
.code-examples, .solid-examples, .pattern-examples {
    margin-top: 2rem;
}

.code-tabs {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 1rem;
}

.code-tab {
    padding: 0.5rem 1rem;
    border: none;
    background: #f8f9fa;
    border-radius: 5px 5px 0 0;
    cursor: pointer;
    transition: all 0.3s ease;
}

.code-tab.active {
    background: #667eea;
    color: white;
}

.code-content {
    display: none;
}

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

.code-content h4 {
    margin-bottom: 1rem;
    color: #333;
}

/* SOLID Principles */
.solid-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.solid-principle {
    background: #f8f9fa;
    border-radius: 10px;
    padding: 1.5rem;
    cursor: pointer;
    transition: all 0.3s ease;
    border-left: 4px solid #667eea;
}

.solid-principle:hover, .solid-principle.selected {
    transform: translateY(-3px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    background: #e8f4fd;
}

.solid-principle.selected {
    border-left-color: #27ae60;
    background: #e8f5e8;
}

.solid-principle h3 {
    color: #333;
    margin-bottom: 0.5rem;
    font-size: 1.2rem;
}

.solid-principle p {
    color: #666;
    margin-bottom: 1rem;
    font-size: 0.95rem;
}

.principle-visual {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.bad-example, .good-example {
    padding: 0.5rem;
    border-radius: 5px;
    font-size: 0.85rem;
    text-align: center;
}

.bad-example {
    background: #ffe6e6;
    color: #c0392b;
    border: 1px solid #fadbd8;
}

.good-example {
    background: #e8f5e8;
    color: #27ae60;
    border: 1px solid #d5f2d5;
}

.principle-detail {
    margin-top: 2rem;
    padding: 1.5rem;
    background: #f8f9fa;
    border-radius: 10px;
}

.example-comparison {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
    margin-top: 1rem;
}

.bad-example-code, .good-example-code {
    background: white;
    border-radius: 8px;
    padding: 1rem;
    border-left: 4px solid #e74c3c;
}

.good-example-code {
    border-left-color: #27ae60;
}

.bad-example-code h4, .good-example-code h4 {
    margin-bottom: 0.5rem;
    font-size: 1rem;
}

/* Design Patterns */
.patterns-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.pattern-card {
    background: #f8f9fa;
    border-radius: 10px;
    padding: 1.5rem;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
    border-left: 4px solid #667eea;
}

.pattern-card:hover, .pattern-card.selected {
    transform: translateY(-3px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    background: #e8f4fd;
}

.pattern-card.selected {
    border-left-color: #27ae60;
    background: #e8f5e8;
}

.pattern-card h3 {
    color: #333;
    margin-bottom: 0.5rem;
}

.pattern-card p {
    color: #666;
    margin-bottom: 1rem;
    font-size: 0.9rem;
}

.pattern-visual {
    padding: 1rem;
    background: white;
    border-radius: 8px;
    margin-top: 1rem;
}

.singleton-demo, .factory-demo, .observer-demo, .strategy-demo {
    padding: 0.8rem;
    background: #667eea;
    color: white;
    border-radius: 5px;
    font-weight: 500;
}

.pattern-detail {
    margin-top: 2rem;
    padding: 1.5rem;
    background: #f8f9fa;
    border-radius: 10px;
    display: none;
}

.pattern-detail.active {
    display: block !important;
}

/* Comparison Section */
.comparison-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.comparison-card {
    background: #f8f9fa;
    border-radius: 10px;
    padding: 1.5rem;
    border-left: 4px solid #667eea;
}

.comparison-card h3 {
    color: #333;
    margin-bottom: 1rem;
}

.comparison-table table {
    width: 100%;
    border-collapse: collapse;
    background: white;
    border-radius: 8px;
    overflow: hidden;
}

.comparison-table th, .comparison-table td {
    padding: 0.8rem;
    text-align: left;
    border-bottom: 1px solid #eee;
}

.comparison-table th {
    background: #667eea;
    color: white;
    font-weight: 500;
}

.comparison-table tr:nth-child(even) {
    background: #f8f9fa;
}

.use-cases {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
}

.python-cases, .go-cases {
    background: white;
    padding: 1rem;
    border-radius: 8px;
}

.python-cases h4 {
    color: #3776ab;
    margin-bottom: 0.5rem;
}

.go-cases h4 {
    color: #00add8;
    margin-bottom: 0.5rem;
}

.use-cases ul {
    list-style: none;
    padding: 0;
}

.use-cases li {
    padding: 0.3rem 0;
    padding-left: 1rem;
    position: relative;
}

.use-cases li::before {
    content: "▶";
    position: absolute;
    left: 0;
    color: #667eea;
}

/* Code Comparison */
.code-comparison {
    margin-top: 2rem;
}

.comparison-example {
    margin-bottom: 2rem;
}

.comparison-example h4 {
    color: #333;
    margin-bottom: 1rem;
    text-align: center;
}

.code-side-by-side {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

.python-code, .go-code {
    background: #f8f9fa;
    border-radius: 8px;
    overflow: hidden;
}

.python-code h5 {
    background: #3776ab;
    color: white;
    padding: 0.8rem;
    margin: 0;
    font-size: 1rem;
}

.go-code h5 {
    background: #00add8;
    color: white;
    padding: 0.8rem;
    margin: 0;
    font-size: 1rem;
}

/* Code Blocks */
pre {
    margin: 0;
    overflow-x: auto;
}

pre code {
    font-size: 0.85rem;
    line-height: 1.4;
}

.code-content pre {
    background: #2d3748;
    color: #e2e8f0;
    padding: 1rem;
    border-radius: 8px;
    overflow-x: auto;
}

/* Responsive Design */
@media (max-width: 768px) {
    header h1 {
        font-size: 2rem;
    }

    main {
        padding: 1rem;
    }

    .concept-grid, .solid-grid, .patterns-grid, .comparison-grid {
        grid-template-columns: 1fr;
    }

    .example-comparison, .code-side-by-side, .use-cases {
        grid-template-columns: 1fr;
    }

    .mvc-demo {
        flex-direction: column;
    }

    .microservices-demo {
        grid-template-columns: 1fr;
    }

    .main-nav {
        flex-direction: column;
        align-items: center;
    }

    .nav-btn {
        width: 200px;
    }
}

@media (max-width: 480px) {
    .content-section {
        padding: 1rem;
    }

    .concept-card, .solid-principle, .pattern-card, .comparison-card {
        padding: 1rem;
    }

    pre code {
        font-size: 0.75rem;
    }
}