/* ============================================
   顶部导航栏样式
   ============================================ */

.site-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    height: var(--header-height);
    background: #fff;
    border-bottom: 1px solid var(--border-color);
    box-shadow: var(--shadow-sm);
}

#site-header { height: var(--header-height); }

.site-header-inner {
    height: 100%;
    max-width: var(--content-max);
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    align-items: center;
    gap: 40px;
}

/* Logo */
.site-logo {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 20px;
    font-weight: 700;
    color: var(--brand-dark);
    flex-shrink: 0;
}

.site-logo .logo-icon { display:block; width:42px; height:42px; flex:0 0 42px; object-fit:contain; }

.site-logo:hover {
    color: var(--brand-dark);
}

/* 主导航 */
.main-nav {
    flex: 1;
    display: flex;
    align-items: center;
    gap: 4px;
}

.nav-item {
    position: relative;
}

.nav-link {
    display: block;
    padding: 8px 16px;
    color: var(--text-primary);
    font-size: 15px;
    font-weight: 500;
    border-radius: var(--radius-sm);
    transition: var(--transition);
}

.nav-link:hover {
    color: var(--brand-blue-light);
    background: var(--bg-hover);
}

.nav-item.active .nav-link {
    color: var(--brand-red);
    font-weight: 600;
}

/* 右侧操作区 */
.header-actions {
    display: flex;
    align-items: center;
    gap: 12px;
    flex-shrink: 0;
}

.header-search {
    display: flex;
    align-items: center;
    width: 200px;
    height: 36px;
    padding: 0 12px;
    background: var(--bg-page);
    border-radius: 18px;
    border: 1px solid transparent;
    transition: var(--transition);
}

.header-search:focus-within {
    border-color: var(--brand-blue-light);
    background: #fff;
}

.header-search input {
    flex: 1;
    border: none;
    outline: none;
    background: transparent;
    font-size: 13px;
    color: var(--text-primary);
}

.header-search .search-icon {
    color: var(--text-tertiary);
    font-size: 16px;
}

.header-login {
    padding: 6px 16px;
    font-size: 14px;
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    transition: var(--transition);
    cursor: pointer;
    background: #fff;
}

.header-login:hover {
    color: var(--brand-blue-light);
    border-color: var(--brand-blue-light);
}