/* Header */
.site-header {
    position: sticky; top: 0; z-index: 50;
    background: #fff; border-bottom: 1px solid #e5e7eb;
}
.site-header .container {
    max-width: 1080px; margin: 0 auto;
    padding: 12px 16px;
    display: flex; align-items: center; justify-content: space-between;
}
.site-header .brand {
    font: 700 1.125rem/1.2 system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
    color: #111827; text-decoration: none;
}
.site-header .brand:hover { text-decoration: underline; }