/* Main Styles */
:root {
    --primary-color: #0969da;
    --primary-hover: #0550ae;
    --bg-color: #ffffff;
    --text-color: #24292f;
    --text-muted: #656d76;
    --border-color: #d0d7de;
    --subtle-bg: #f6f8fa;
    --card-shadow: 0 1px 3px rgba(0,0,0,0.12);
    --card-shadow-hover: 0 4px 12px rgba(0,0,0,0.15);
    --max-width: 1200px;
}

@media (prefers-color-scheme: dark) {
    :root {
        --primary-color: #58a6ff;
        --primary-hover: #79c0ff;
        --bg-color: #0d1117;
        --text-color: #c9d1d9;
        --text-muted: #8b949e;
        --border-color: #30363d;
        --subtle-bg: #161b22;
        --card-shadow: 0 1px 3px rgba(0,0,0,0.4);
        --card-shadow-hover: 0 4px 12px rgba(0,0,0,0.5);
    }
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans", Helvetica, Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
    transition: background-color 0.3s ease, color 0.3s ease;
}

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 2rem;
}

.main-content {
    min-height: calc(100vh - 200px);
    padding-top: 80px;
}

h1, h2, h3, h4, h5, h6 {
    margin-bottom: 1rem;
    font-weight: 600;
    line-height: 1.25;
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.5rem; }

p {
    margin-bottom: 1rem;
}

a {
    color: var(--primary-color);
    text-decoration: none;
    transition: color 0.2s ease;
}

a:hover {
    color: var(--primary-hover);
    text-decoration: underline;
}

.section {
    padding: 3rem 0;
}

.section-title {
    text-align: center;
    margin-bottom: 2.5rem;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid var(--border-color);
    display: inline-block;
    width: 100%;
}

.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    background-color: var(--primary-color);
    color: white;
    border-radius: 6px;
    border: none;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 500;
    transition: background-color 0.2s ease, transform 0.1s ease;
}

.btn:hover {
    background-color: var(--primary-hover);
    color: white;
    text-decoration: none;
    transform: translateY(-2px);
}

.btn-secondary {
    background-color: var(--subtle-bg);
    color: var(--text-color);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover {
    background-color: var(--border-color);
}

/* Responsive */
@media (max-width: 768px) {
    .container {
        padding: 0 1rem;
    }
    
    h1 { font-size: 2rem; }
    h2 { font-size: 1.5rem; }
    h3 { font-size: 1.25rem; }
    
    .section {
        padding: 2rem 0;
    }
}