/* ===== SITE HEADER ===== */
.site-header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(255, 255, 255, 0.92);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
    transition: box-shadow var(--transition);
}
.site-header.scrolled {
    box-shadow: var(--shadow);
}
.header-inner {
    display: flex;
    align-items: center;
    gap: 24px;
    height: 68px;
}

/* Logo */
.site-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
    flex-shrink: 0;
}
.logo-icon {
    font-size: 1.5rem;
    line-height: 1;
}
.logo-text {
    font-size: 1.1rem;
    font-weight: 800;
    color: var(--text);
    letter-spacing: -0.02em;
}
.site-logo:hover .logo-text { color: var(--primary); }
.site-logo img { height: 36px; width: auto; }

/* Primary Navigation */
.primary-nav { flex: 1; }
.nav-menu {
    display: flex;
    align-items: center;
    gap: 4px;
    list-style: none;
    margin: 0;
    padding: 0;
}
.nav-menu > li > a {
    display: block;
    padding: 8px 12px;
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-muted);
    border-radius: var(--radius-sm);
    transition: all var(--transition);
    text-decoration: none;
}
.nav-menu > li > a:hover,
.nav-menu > li.current-menu-item > a,
.nav-menu > li.current-page-ancestor > a {
    color: var(--primary);
    background: var(--primary-glow);
}

/* Header Actions */
.header-actions {
    display: flex;
    align-items: center;
    gap: 8px;
    flex-shrink: 0;
}
.search-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 38px;
    height: 38px;
    border: none;
    background: transparent;
    border-radius: var(--radius-sm);
    color: var(--text-muted);
    cursor: pointer;
    transition: all var(--transition);
}
.search-toggle:hover { color: var(--primary); background: var(--primary-glow); }

/* Header Search */
.header-search {
    overflow: hidden;
    max-height: 0;
    transition: max-height 0.25s ease, padding 0.25s ease, border-color 0.25s ease;
    border-top: 0px solid var(--border);
}
.header-search.is-open {
    max-height: 80px;
    padding: 12px 0;
    border-top-width: 1px;
}
.search-input-wrap {
    display: flex;
    align-items: center;
    gap: 8px;
    background: var(--bg);
    border: 1.5px solid var(--border);
    border-radius: var(--radius);
    padding: 8px 14px;
    transition: border-color var(--transition), box-shadow var(--transition);
}
.search-input-wrap:focus-within {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px var(--primary-glow);
}
.search-icon { color: var(--text-light); flex-shrink: 0; }
.search-input {
    flex: 1;
    border: none;
    background: transparent;
    font-size: 0.95rem;
    font-family: var(--font-sans);
    color: var(--text);
}
.search-input:focus { outline: none; }
.search-input::placeholder { color: var(--text-light); }
.search-submit {
    padding: 6px 14px;
    background: var(--primary);
    color: #fff;
    border: none;
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    font-weight: 600;
    cursor: pointer;
    transition: background var(--transition);
}
.search-submit:hover { background: var(--secondary); }
.search-close {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 30px;
    height: 30px;
    border: none;
    background: transparent;
    color: var(--text-light);
    cursor: pointer;
    border-radius: 50%;
    transition: all var(--transition);
}
.search-close:hover { color: var(--text); background: var(--border); }

/* Mobile Menu Toggle */
.mobile-menu-toggle {
    display: none;
    align-items: center;
    justify-content: center;
    width: 38px;
    height: 38px;
    border: none;
    background: transparent;
    cursor: pointer;
    border-radius: var(--radius-sm);
    padding: 4px;
}
.hamburger { display: flex; flex-direction: column; gap: 5px; }
.hamburger span {
    display: block;
    width: 22px;
    height: 2px;
    background: var(--text);
    border-radius: 2px;
    transition: all 0.3s ease;
}
.mobile-menu-toggle.is-active .hamburger span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.mobile-menu-toggle.is-active .hamburger span:nth-child(2) { opacity: 0; transform: scaleX(0); }
.mobile-menu-toggle.is-active .hamburger span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* Page Hero */
.page-hero {
    background: linear-gradient(135deg, #f0f4ff 0%, var(--bg) 100%);
    padding: 56px 0 48px;
    border-bottom: 1px solid var(--border);
}
.page-hero h1 { margin-top: 8px; }
.page-hero__desc { font-size: 1.05rem; margin-top: 12px; max-width: 600px; }
.page-hero--archive { padding: 48px 0 40px; }
.page-hero--sm { padding: 40px 0 0; margin-bottom: 40px; }

/* ===== RESPONSIVE HEADER ===== */
@media (max-width: 900px) {
    .primary-nav { display: none; }
    .mobile-menu-toggle { display: flex; }

    .primary-nav.is-open {
        display: block;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: var(--bg-white);
        border-bottom: 1px solid var(--border);
        box-shadow: var(--shadow-md);
        padding: 16px;
        z-index: 99;
    }
    .primary-nav.is-open .nav-menu { flex-direction: column; align-items: stretch; gap: 2px; }
    .primary-nav.is-open .nav-menu > li > a { padding: 12px 16px; }
}
.site-header { position: relative; }
@media (max-width: 900px) { .site-header { position: sticky; } }

@media (max-width: 768px) {
    .header-actions .btn { display: none; }
}