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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.6;
    color: #333;
    background: #f5f5f5;
}

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

/* Navigation */
nav {
    background: #2c3e50;
    color: white;
    padding: 1rem 0;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

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

nav h1 {
    font-size: 1.5rem;
}

nav h1 a {
    color: white;
    text-decoration: none;
}

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

nav a {
    color: white;
    text-decoration: none;
    transition: opacity 0.2s;
}

nav a:hover {
    opacity: 0.8;
}

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

/* Hero section */
.hero {
    background: white;
    padding: 3rem;
    border-radius: 8px;
    text-align: center;
    margin-bottom: 2rem;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.hero h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    color: #2c3e50;
}

.hero p {
    font-size: 1.2rem;
    color: #666;
    margin-bottom: 2rem;
}

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

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border-radius: 4px;
    text-decoration: none;
    font-weight: 500;
    transition: transform 0.2s, box-shadow 0.2s;
    border: none;
    cursor: pointer;
    font-size: 1rem;
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}

.btn-primary {
    background: #3498db;
    color: white;
}

.btn-secondary {
    background: #95a5a6;
    color: white;
}

/* Features */
.features {
    background: white;
    padding: 2rem;
    border-radius: 8px;
    margin-bottom: 2rem;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.features h3 {
    text-align: center;
    margin-bottom: 2rem;
    font-size: 2rem;
    color: #2c3e50;
}

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

.feature {
    text-align: center;
}

.feature h4 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
    color: #2c3e50;
}

.feature p {
    color: #666;
}

/* Quick start */
.quick-start {
    background: white;
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.quick-start h3 {
    margin-bottom: 1rem;
    font-size: 1.8rem;
    color: #2c3e50;
}

pre {
    background: #2c3e50;
    color: #ecf0f1;
    padding: 1.5rem;
    border-radius: 4px;
    overflow-x: auto;
}

code {
    font-family: 'Courier New', monospace;
    font-size: 0.9rem;
}

/* Module grid */
.module-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.5rem;
}

.module-card {
    background: white;
    padding: 1.5rem;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
    transition: transform 0.2s;
}

.module-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 4px 16px rgba(0,0,0,0.15);
}

.module-card h3 {
    color: #2c3e50;
    margin-bottom: 0.5rem;
}

.module-card .version {
    color: #3498db;
    font-size: 0.9rem;
    margin-bottom: 1rem;
}

.module-card .description {
    color: #666;
    margin-bottom: 1rem;
    min-height: 3rem;
}

.module-card .meta {
    display: flex;
    justify-content: space-between;
    font-size: 0.9rem;
    color: #999;
    margin-bottom: 1rem;
}

.module-card .btn {
    width: 100%;
    text-align: center;
}

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

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: #2c3e50;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-size: 1rem;
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: #3498db;
}

.form-group small {
    display: block;
    margin-top: 0.25rem;
    color: #999;
    font-size: 0.875rem;
}

/* Upload form */
.upload-form {
    background: white;
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
    margin-bottom: 2rem;
}

.result {
    margin-top: 1rem;
    padding: 1rem;
    border-radius: 4px;
    display: none;
}

.result.loading,
.result.success,
.result.error {
    display: block;
}

.result.loading {
    background: #f0f8ff;
    color: #3498db;
}

.result.success {
    background: #d4edda;
    color: #155724;
}

.result.error {
    background: #f8d7da;
    color: #721c24;
}

/* Error message */
.error {
    background: #f8d7da;
    color: #721c24;
    padding: 1rem;
    margin-bottom: 1.5rem;
    border-radius: 4px;
    border: 1px solid #f5c6cb;
    font-weight: 500;
}

/* Specification */
.spec {
    background: white;
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
    margin-bottom: 2rem;
}

.spec h3 {
    color: #2c3e50;
    margin-bottom: 1rem;
}

.spec h4 {
    color: #2c3e50;
    margin: 1.5rem 0 0.5rem;
}

.spec ul {
    margin-left: 2rem;
    margin-bottom: 1rem;
}

.spec li {
    margin-bottom: 0.5rem;
    color: #666;
}

/* ChatGPT section */
.chatgpt-section {
    background: white;
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.chatgpt-section h3 {
    color: #2c3e50;
    margin-bottom: 1rem;
}

.prompt-box {
    background: #f8f9fa;
    padding: 1.5rem;
    border-radius: 4px;
    border-left: 4px solid #3498db;
    margin: 1rem 0;
}

.prompt-box pre {
    background: #2c3e50;
    margin: 1rem 0;
}

blockquote {
    background: #f8f9fa;
    padding: 1rem;
    border-left: 4px solid #95a5a6;
    margin: 1rem 0;
    font-style: italic;
    color: #666;
}

/* Empty state */
.empty {
    text-align: center;
    color: #999;
    padding: 2rem;
    background: white;
    border-radius: 8px;
}

/* Footer */
footer {
    background: #2c3e50;
    color: white;
    padding: 1.5rem 0;
    text-align: center;
    margin-top: 2rem;
}

footer a {
    color: #3498db;
    text-decoration: none;
}

footer a:hover {
    text-decoration: underline;
}

/* Section styling */
section {
    background: white;
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

section h2 {
    color: #2c3e50;
    margin-bottom: 1rem;
}

section > p {
    color: #666;
    margin-bottom: 1.5rem;
}

/* GitHub OAuth button */
.btn-github {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    background: #24292e;
    color: white;
    padding: 0.75rem 1.5rem;
    border-radius: 4px;
    text-decoration: none;
    font-weight: 500;
    transition: background 0.2s;
    border: none;
    cursor: pointer;
    width: 100%;
    justify-content: center;
    font-size: 1rem;
}

.btn-github:hover {
    background: #1b1f23;
}

.btn-github svg {
    flex-shrink: 0;
}

.divider {
    display: flex;
    align-items: center;
    text-align: center;
    margin: 1.5rem 0;
    color: #666;
}

.divider::before,
.divider::after {
    content: '';
    flex: 1;
    border-bottom: 1px solid #ddd;
}

.divider span {
    padding: 0 1rem;
    font-size: 0.9rem;
}

/* Responsive */
@media (max-width: 768px) {
    nav .container {
        flex-direction: column;
        gap: 1rem;
    }
    
    nav ul {
        gap: 1rem;
    }
    
    .hero h2 {
        font-size: 2rem;
    }
    
    .cta {
        flex-direction: column;
    }
    
    .feature-grid {
        grid-template-columns: 1fr;
    }
    
    .module-grid {
        grid-template-columns: 1fr;
    }
}