:root {
    --primary-color: #1D4ED8;
    --text-main: #0F172A;
    --text-muted: #475569;
    --bg-main: #F7F9FB;
    --bg-card: #FFFFFF;
    --border-color: #E2E8F0;
    --sidebar-width: 280px;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-main);
    background-color: var(--bg-main);
}

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

/* Header */
.site-header {
    background-color: var(--bg-card);
    border-bottom: 1px solid var(--border-color);
    padding: 40px 0;
    text-align: center;
}

.site-header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 8px;
    color: var(--primary-color);
}

.site-header p {
    font-size: 1.25rem;
    color: var(--text-muted);
}

.last-updated {
    font-size: 0.9rem !important;
    margin-top: 16px;
    color: #64748B !important;
}

/* Main Layout */
.main-content {
    display: flex;
    gap: 40px;
    margin-top: 40px;
    margin-bottom: 60px;
    align-items: flex-start;
}

/* Sidebar Navigation */
.sidebar {
    width: var(--sidebar-width);
    flex-shrink: 0;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 24px;
    position: sticky;
    top: 24px;
    max-height: calc(100vh - 48px);
    overflow-y: auto;
}

.sidebar h2 {
    font-size: 1.1rem;
    margin-bottom: 16px;
    padding-bottom: 12px;
    border-bottom: 1px solid var(--border-color);
}

.sidebar ul {
    list-style: none;
}

.sidebar li {
    margin-bottom: 12px;
}

.sidebar a {
    text-decoration: none;
    color: var(--text-muted);
    font-size: 0.95rem;
    transition: color 0.2s;
    display: block;
}

.sidebar a:hover {
    color: var(--primary-color);
}

/* Content Area */
.content {
    flex-grow: 1;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 40px;
}

.content section {
    margin-bottom: 40px;
}

.content section:last-child {
    margin-bottom: 0;
}

.content h2 {
    font-size: 1.5rem;
    color: var(--text-main);
    margin-bottom: 16px;
    padding-bottom: 8px;
    border-bottom: 1px solid var(--border-color);
}

.content h3 {
    font-size: 1.1rem;
    margin-top: 24px;
    margin-bottom: 12px;
    color: var(--text-main);
}

.content p {
    color: var(--text-muted);
    margin-bottom: 16px;
}

.content ul {
    color: var(--text-muted);
    margin-bottom: 16px;
    padding-left: 24px;
}

.content li {
    margin-bottom: 8px;
}

.content a {
    color: var(--primary-color);
    text-decoration: none;
}

.content a:hover {
    text-decoration: underline;
}

/* Footer */
.site-footer {
    background-color: var(--bg-card);
    border-top: 1px solid var(--border-color);
    padding: 30px 0;
    text-align: center;
    color: var(--text-muted);
}

.site-footer p {
    margin-bottom: 8px;
}

.site-footer a {
    color: var(--primary-color);
    text-decoration: none;
}

.footer-last-updated {
    font-size: 0.85rem;
    color: #94A3B8;
}

/* Responsive */
@media (max-width: 860px) {
    .main-content {
        flex-direction: column;
    }

    .sidebar {
        width: 100%;
        position: static;
        max-height: none;
        margin-bottom: 24px;
    }
    
    .content {
        padding: 24px;
    }
}