/* === Header === */
.site-header { position: fixed; top: 0; left: 0; right: 0; z-index: 100; background: var(--color-bg); border-bottom: 1px solid var(--color-border); height: var(--header-height); }
.header-inner { display: flex; align-items: center; justify-content: space-between; height: 100%; }
.site-logo { display: flex; align-items: center; gap: 8px; font-size: 1.25rem; font-weight: 700; color: var(--color-text); }
.site-logo:hover { color: var(--color-primary); }
.site-logo .logo-icon { width: 32px; height: 32px; background: var(--color-primary); border-radius: 8px; display: flex; align-items: center; justify-content: center; color: #fff; font-weight: 700; font-size: 1rem; }

/* Nav */
.main-nav { display: flex; align-items: center; gap: 4px; margin-left: 16px; margin-right: auto; }
.main-nav a { padding: 8px 16px; color: var(--color-text-secondary); font-size: 0.9375rem; border-radius: var(--radius); transition: all var(--transition); }
.main-nav a:hover, .main-nav a.active { color: var(--color-primary); background: var(--color-primary-bg); }

/* Search */
.header-search { position: relative; }
.header-search input { width: 240px; padding: 8px 16px 8px 40px; border: 1px solid var(--color-border); border-radius: 20px; font-size: 0.875rem; outline: none; transition: all var(--transition); }
.header-search input:focus { border-color: var(--color-primary); box-shadow: 0 0 0 3px var(--color-primary-bg); }
.header-search .search-icon { position: absolute; left: 14px; top: 50%; transform: translateY(-50%); color: var(--color-text-muted); }

/* Mobile menu */
.mobile-menu-btn { display: none; width: 40px; height: 40px; align-items: center; justify-content: center; border-radius: var(--radius); }
.mobile-menu-btn:hover { background: var(--color-bg-hover); }
.hamburger { width: 20px; height: 14px; position: relative; }
.hamburger span { display: block; width: 100%; height: 2px; background: var(--color-text); border-radius: 1px; position: absolute; left: 0; transition: all 0.3s; }
.hamburger span:nth-child(1) { top: 0; }
.hamburger span:nth-child(2) { top: 6px; }
.hamburger span:nth-child(3) { top: 12px; }

/* === Footer === */
.site-footer { background: var(--color-bg-secondary); border-top: 1px solid var(--color-border); padding: 32px 0; margin-top: 60px; }
.footer-inner { display: flex; align-items: center; justify-content: space-between; font-size: 0.8125rem; color: var(--color-text-muted); }

/* === Main Content === */
.site-main { min-height: calc(100vh - var(--header-height) - 120px); padding-top: var(--header-height); }

/* === Grid === */
.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 20px; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }

/* === Content with sidebar === */
.content-with-sidebar { display: grid; grid-template-columns: 1fr 280px; gap: 32px; }

/* === Mobile Overlay === */
.mobile-overlay { display: none; position: fixed; inset: 0; background: rgba(0,0,0,0.4); z-index: 99; }
.mobile-overlay.active { display: block; }

/* === Responsive === */
@media (max-width: 1024px) {
  .content-with-sidebar { grid-template-columns: 1fr; }
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .grid-3 { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 768px) {
  .main-nav, .header-search { display: none; }
  .mobile-menu-btn { display: flex; }
  .main-nav.active { display: flex; flex-direction: column; position: absolute; top: var(--header-height); left: 0; right: 0; background: var(--color-bg); border-bottom: 1px solid var(--color-border); padding: 12px 20px; z-index: 98; }
  .main-nav.active a { padding: 12px 0; }
  .grid-4, .grid-3, .grid-2 { grid-template-columns: 1fr; }
  .footer-inner { flex-direction: column; gap: 8px; text-align: center; }
}