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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    line-height: 1.6;
    color: #333;
    background: #fff;
}

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

/* Header */
header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 80px 20px;
    text-align: center;
}

header h1 {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 10px;
    font-family: 'Courier New', monospace;
}

.tagline {
    font-size: 1.5rem;
    margin-bottom: 5px;
    opacity: 0.95;
}

.tagline-sub {
    font-size: 1.1rem;
    opacity: 0.8;
    margin-bottom: 10px;
}

.buttons {
    display: flex;
    gap: 15px;
    justify-content: center;
    flex-wrap: wrap;
    margin-top: 30px;
}

.btn {
    display: inline-block;
    padding: 12px 30px;
    text-decoration: none;
    border-radius: 6px;
    font-weight: 600;
    transition: all 0.3s ease;
}

.btn-primary {
    background: white;
    color: #667eea;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.2);
}

.btn-secondary {
    background: rgba(255,255,255,0.2);
    color: white;
    border: 2px solid white;
}

.btn-secondary:hover {
    background: rgba(255,255,255,0.3);
}

/* Problem Section */
.problem {
    padding: 60px 20px;
    background: white;
}

.problem h2 {
    font-size: 2.5rem;
    margin-bottom: 20px;
    text-align: center;
    color: #2d3748;
}

.problem p {
    font-size: 1.1rem;
    max-width: 800px;
    margin: 0 auto 20px;
    text-align: center;
    color: #4a5568;
}

.highlight {
    margin-top: 30px;
    padding: 20px;
    background: #edf2f7;
    border-left: 4px solid #667eea;
    border-radius: 4px;
}

/* Demo Section */
.demo-section {
    background: #f8f9fa;
    padding: 60px 20px;
}

.demo-section h2 {
    font-size: 2.5rem;
    margin-bottom: 10px;
    text-align: center;
    color: #2d3748;
}

.demo-subtitle {
    text-align: center;
    color: #718096;
    margin-bottom: 40px;
    font-size: 1.1rem;
}

.demo-container {
    background: white;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.1);
    overflow: hidden;
    max-width: 900px;
    margin: 0 auto;
}

.demo-tabs {
    display: flex;
    border-bottom: 2px solid #e2e8f0;
    background: #f7fafc;
}

.demo-tab {
    flex: 1;
    padding: 16px 20px;
    border: none;
    background: transparent;
    font-size: 1rem;
    font-weight: 600;
    color: #718096;
    cursor: pointer;
    transition: all 0.3s ease;
    border-bottom: 3px solid transparent;
    margin-bottom: -2px;
}

.demo-tab:hover {
    color: #4a5568;
    background: #edf2f7;
}

.demo-tab.active {
    color: #667eea;
    border-bottom-color: #667eea;
    background: white;
}

.demo-content {
    min-height: 400px;
}

.demo-panel {
    display: none;
    padding: 30px;
}

.demo-panel.active {
    display: block;
}

.mockup-source {
    background: #1a202c;
    color: #e2e8f0;
    padding: 24px;
    border-radius: 8px;
    overflow-x: auto;
    font-family: 'Courier New', Monaco, monospace;
    font-size: 0.85rem;
    line-height: 1.5;
}

.mockup-source code {
    color: #e2e8f0;
}

/* Slide Viewer */
.slide-viewer {
    text-align: center;
}

.slide-display {
    background: #f7fafc;
    border: 2px solid #e2e8f0;
    border-radius: 8px;
    min-height: 300px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 20px;
    overflow: hidden;
}

.slide-display img {
    max-width: 100%;
    max-height: 400px;
    object-fit: contain;
}

.slide-placeholder {
    text-align: center;
    color: #a0aec0;
    padding: 60px;
}

.slide-placeholder span {
    display: block;
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 10px;
}

.slide-placeholder small {
    font-size: 1rem;
    opacity: 0.7;
}

.slide-nav {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 20px;
    margin-bottom: 20px;
}

.slide-nav button {
    padding: 10px 20px;
    border: 2px solid #e2e8f0;
    background: white;
    border-radius: 6px;
    font-weight: 600;
    color: #4a5568;
    cursor: pointer;
    transition: all 0.3s ease;
}

.slide-nav button:hover:not(:disabled) {
    border-color: #667eea;
    color: #667eea;
}

.slide-nav button:disabled {
    opacity: 0.4;
    cursor: not-allowed;
}

.slide-counter {
    font-weight: 600;
    color: #4a5568;
    min-width: 60px;
}

.slide-thumbs {
    display: flex;
    gap: 10px;
    justify-content: center;
}

.thumb {
    width: 40px;
    height: 40px;
    border: 2px solid #e2e8f0;
    border-radius: 6px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    color: #718096;
    cursor: pointer;
    transition: all 0.3s ease;
}

.thumb:hover {
    border-color: #667eea;
    color: #667eea;
}

.thumb.active {
    background: #667eea;
    border-color: #667eea;
    color: white;
}

/* Why Section */
.why {
    background: white;
    padding: 60px 20px;
}

.why h2 {
    font-size: 2.5rem;
    margin-bottom: 40px;
    text-align: center;
    color: #2d3748;
}

.benefits {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin-bottom: 30px;
}

.benefit {
    background: #f8f9fa;
    padding: 30px;
    border-radius: 8px;
    border: 2px solid #e2e8f0;
}

.benefit h3 {
    font-size: 1.5rem;
    margin-bottom: 10px;
    color: #2d3748;
}

.benefit p {
    color: #4a5568;
}

.principles {
    text-align: center;
    font-size: 1.1rem;
    color: #4a5568;
    margin-top: 40px;
}

/* Examples Section */
.examples {
    background: #f8f9fa;
    padding: 60px 20px;
}

.examples h2 {
    font-size: 2.5rem;
    margin-bottom: 10px;
    text-align: center;
    color: #2d3748;
}

.examples-subtitle {
    text-align: center;
    color: #718096;
    margin-bottom: 40px;
    font-size: 1.1rem;
}

.example-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 25px;
}

.example-card {
    background: white;
    border-radius: 12px;
    overflow: hidden;
    border: 2px solid #e2e8f0;
    transition: all 0.3s ease;
    text-decoration: none;
    color: inherit;
    display: block;
}

.example-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 24px rgba(0,0,0,0.1);
    border-color: #667eea;
}

.example-preview {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    height: 140px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.example-placeholder {
    font-size: 3rem;
}

.example-info {
    padding: 20px;
}

.example-info h3 {
    font-size: 1.25rem;
    margin-bottom: 8px;
    color: #2d3748;
}

.example-info p {
    color: #718096;
    font-size: 0.95rem;
}

/* Usage Section */
.usage {
    background: white;
    padding: 60px 20px;
}

.usage h2 {
    font-size: 2.5rem;
    margin-bottom: 40px;
    text-align: center;
    color: #2d3748;
}

.usage-options {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 30px;
}

.usage-option {
    background: #f8f9fa;
    padding: 30px;
    border-radius: 8px;
    border: 2px solid #e2e8f0;
}

.usage-option h3 {
    font-size: 1.5rem;
    margin-bottom: 20px;
    color: #2d3748;
}

.usage-option ol {
    margin-left: 20px;
    color: #4a5568;
}

.usage-option li {
    margin-bottom: 12px;
    line-height: 1.6;
}

.usage-option a {
    color: #667eea;
    text-decoration: none;
}

.usage-option a:hover {
    text-decoration: underline;
}

.code-block {
    background: #1a202c;
    color: #e2e8f0;
    padding: 16px;
    border-radius: 6px;
    margin: 12px 0;
    font-family: 'Courier New', Monaco, monospace;
    font-size: 0.85rem;
    overflow-x: auto;
    line-height: 1.5;
}

/* Footer */
footer {
    background: #2d3748;
    color: white;
    padding: 40px 20px;
    text-align: center;
}

footer a {
    color: #a0aec0;
    text-decoration: none;
    margin: 0 10px;
    transition: color 0.3s ease;
}

footer a:hover {
    color: white;
}

/* Responsive */
@media (max-width: 768px) {
    header h1 {
        font-size: 2.5rem;
    }

    .tagline {
        font-size: 1.2rem;
    }

    .demo-tabs {
        flex-wrap: wrap;
    }

    .demo-tab {
        flex: 1 1 50%;
        padding: 12px;
        font-size: 0.9rem;
    }

    .mockup-source {
        font-size: 0.7rem;
        padding: 16px;
    }

    .problem h2, .why h2, .examples h2, .usage h2, .demo-section h2 {
        font-size: 2rem;
    }

    .slide-nav button {
        padding: 8px 12px;
        font-size: 0.9rem;
    }
}