:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --dark: #0f172a;
    --light: #f8fafc;
    --text: #1f2937;
    --text-muted: #64748b;
    --border: #e2e8f0;
    --white: #ffffff;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    color: var(--text);
    background-color: var(--light);
    line-height: 1.7;
    margin: 0;
    padding: 0;
}

header.site-header {
    background: var(--dark);
    color: var(--white);
    padding: 20px 0;
    border-bottom: 4px solid var(--primary);
}

.header-container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
}

.site-logo {
    font-size: 24px;
    font-weight: 800;
    color: var(--white);
    text-decoration: none;
}

.site-logo span {
    color: #38bdf8;
}

.site-tagline {
    margin: 5px 0 0 0;
    font-size: 13px;
    color: var(--text-muted);
}

nav.main-nav a {
    color: var(--white);
    text-decoration: none;
    margin-left: 20px;
    font-size: 14px;
    font-weight: 600;
    transition: color 0.2s;
}

nav.main-nav a:hover {
    color: #38bdf8;
}

main.site-main {
    max-width: 900px;
    margin: 40px auto;
    padding: 0 20px;
}

.card-box {
    background: var(--white);
    padding: 40px;
    border-radius: 12px;
    box-shadow: 0 4px 6px -1px rgba(0,0,0,0.05), 0 2px 4px -1px rgba(0,0,0,0.03);
}

.ad-block {
    margin: 30px 0;
    background: #f1f5f9;
    padding: 20px;
    text-align: center;
    border-radius: 8px;
    border: 1px dashed var(--border);
}

.ad-block span {
    color: var(--text-muted);
    font-size: 11px;
    text-transform: uppercase;
    letter-spacing: 1.5px;
    font-weight: bold;
}

footer.site-footer {
    text-align: center;
    padding: 40px 20px;
    color: var(--text-muted);
    font-size: 13px;
    border-top: 1px solid var(--border);
    margin-top: 60px;
    background: var(--white);
}

footer.site-footer p {
    margin: 5px 0;
}