/* 布局系统 */

/* 容器 */
.container {
    width: 100%;
    max-width: var(--container-xl);
    margin: 0 auto;
    padding: 0 var(--space-lg);
}

@media (max-width: 768px) {
    .container {
        padding: 0 var(--space-md);
    }
}

/* ===== 头部导航 ===== */
.site-header {
    position: sticky;
    top: 0;
    z-index: var(--z-sticky);
    background: var(--color-header-bg);
    border-bottom: 1px solid var(--color-border);
    box-shadow: 0 1px 4px rgba(0,0,0,0.06);
    height: var(--header-height);
}

.site-header .container {
    display: flex;
    align-items: center;
    height: 100%;
    gap: var(--space-lg);
}

.logo {
    display: flex;
    align-items: center;
    gap: 8px;
    font-family: var(--font-heading);
    font-size: 1.1rem;
    font-weight: var(--font-weight-bold);
    color: var(--color-primary);
    text-decoration: none;
    flex-shrink: 0;
    letter-spacing: -0.3px;
}

.logo-icon {
    width: 32px;
    height: 32px;
    background: var(--color-primary);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-size: 16px;
    font-weight: bold;
}

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

/* 主导航 */
.main-nav {
    flex: 1;
}

.main-nav ul {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
}

.main-nav ul li a {
    display: block;
    padding: 6px var(--space-md);
    font-size: var(--font-size-sm);
    font-weight: var(--font-weight-medium);
    color: var(--color-text-secondary);
    border-radius: var(--radius-md);
    transition: color var(--transition-fast), background var(--transition-fast);
    white-space: nowrap;
}

.main-nav ul li a:hover,
.main-nav ul li a.active {
    color: var(--color-primary);
    background: var(--color-primary-light);
}

/* 导航搜索 */
.nav-search {
    flex: 0 1 280px;
}

.nav-search-form {
    display: flex;
    align-items: center;
    background: var(--color-background);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-full);
    padding: 4px 4px 4px 14px;
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.nav-search-form:focus-within {
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.12);
}

.nav-search-input {
    flex: 1;
    border: none;
    background: transparent;
    font-size: var(--font-size-sm);
    color: var(--color-text);
    min-width: 0;
    outline: none;
}

.nav-search-input:focus-visible {
    outline: none;
}

.nav-search-input::placeholder {
    color: var(--color-text-muted);
}

.nav-search-btn {
    background: var(--color-primary);
    color: #fff;
    border: none;
    border-radius: var(--radius-full);
    padding: 5px 14px;
    font-size: var(--font-size-sm);
    font-weight: var(--font-weight-medium);
    cursor: pointer;
    transition: background var(--transition-fast);
}

.nav-search-btn:hover {
    background: var(--color-primary-dark);
}

/* 用户菜单 */
.user-menu {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    flex-shrink: 0;
}

.user-info {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}

.user-avatar {
    width: 32px;
    height: 32px;
    background: var(--color-primary);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: var(--font-size-sm);
    font-weight: var(--font-weight-semibold);
    flex-shrink: 0;
}

.user-name {
    font-size: var(--font-size-sm);
    font-weight: var(--font-weight-medium);
    color: var(--color-text);
}

.user-score {
    display: inline-flex;
    align-items: center;
    gap: 3px;
    font-size: var(--font-size-xs);
    color: var(--color-warning);
    background: hsl(38, 95%, 95%);
    padding: 2px 8px;
    border-radius: var(--radius-full);
    font-weight: var(--font-weight-medium);
}

/* 汉堡菜单 */
.menu-toggle {
    display: none;
    flex-direction: column;
    justify-content: center;
    gap: 5px;
    width: 36px;
    height: 36px;
    padding: 6px;
    cursor: pointer;
    border-radius: var(--radius-md);
    transition: background var(--transition-fast);
}

.menu-toggle:hover {
    background: var(--color-background);
}

.menu-toggle span {
    width: 100%;
    height: 2px;
    background: var(--color-text-secondary);
    border-radius: 2px;
    transition: all var(--transition-base);
    display: block;
}

/* 移动端导航 */
.mobile-nav {
    display: none;
    position: absolute;
    top: var(--header-height);
    left: 0;
    right: 0;
    background: var(--color-card);
    border-bottom: 1px solid var(--color-border);
    box-shadow: var(--shadow-md);
    padding: var(--space-md);
    z-index: var(--z-sticky);
}

.mobile-nav.open {
    display: block;
}

.mobile-nav ul {
    display: flex;
    flex-direction: column;
    gap: var(--space-xs);
}

.mobile-nav ul li a {
    display: block;
    padding: var(--space-sm) var(--space-md);
    color: var(--color-text);
    border-radius: var(--radius-md);
    font-size: var(--font-size-base);
}

.mobile-nav ul li a:hover {
    background: var(--color-background);
    color: var(--color-primary);
}

/* ===== 主内容 ===== */
main {
    min-height: calc(100vh - var(--header-height) - 280px);
}

/* ===== 面包屑 ===== */
.breadcrumb {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 4px;
    font-size: var(--font-size-sm);
    color: var(--color-text-muted);
    padding: var(--space-md) 0;
    border-bottom: 1px solid var(--color-border-light);
    margin-bottom: var(--space-xl);
}

.breadcrumb a {
    color: var(--color-text-secondary);
}

.breadcrumb a:hover {
    color: var(--color-primary);
}

.breadcrumb-sep {
    color: var(--color-border);
    margin: 0 2px;
}

.breadcrumb-current {
    color: var(--color-text);
    font-weight: var(--font-weight-medium);
}

/* ===== 页脚 ===== */
.site-footer {
    background: hsl(215, 18%, 22%);
    color: hsl(215, 15%, 75%);
    margin-top: var(--space-3xl);
}

.footer-main {
    padding: var(--space-2xl) 0 var(--space-xl);
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: var(--space-2xl);
}

.footer-brand .footer-logo {
    font-family: var(--font-heading);
    font-size: 1.1rem;
    font-weight: var(--font-weight-bold);
    color: #fff;
    margin-bottom: var(--space-sm);
}

.footer-brand p {
    font-size: var(--font-size-sm);
    line-height: 1.7;
    color: hsl(215, 15%, 65%);
    max-width: 280px;
}

.footer-col h4 {
    font-size: var(--font-size-sm);
    font-weight: var(--font-weight-semibold);
    color: #fff;
    margin-bottom: var(--space-md);
    letter-spacing: 0.3px;
}

.footer-col ul {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.footer-col ul li a {
    font-size: var(--font-size-sm);
    color: hsl(215, 15%, 65%);
    transition: color var(--transition-fast);
}

.footer-col ul li a:hover {
    color: #fff;
}

.footer-bottom {
    border-top: 1px solid hsl(215, 15%, 30%);
    padding: var(--space-md) 0;
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: var(--space-sm);
}

.footer-bottom p {
    font-size: var(--font-size-xs);
    color: hsl(215, 15%, 52%);
}

.footer-bottom a {
    color: hsl(215, 15%, 60%);
    font-size: var(--font-size-xs);
}

.footer-bottom a:hover {
    color: #fff;
}

/* ===== 响应式 ===== */
@media (max-width: 1024px) {
    .footer-grid {
        grid-template-columns: 1fr 1fr;
        gap: var(--space-xl);
    }
}

@media (max-width: 768px) {
    .main-nav,
    .nav-search {
        display: none;
    }

    .menu-toggle {
        display: flex;
        margin-left: auto;
    }

    .footer-grid {
        grid-template-columns: 1fr 1fr;
        gap: var(--space-lg);
    }
}

@media (max-width: 480px) {
    .footer-grid {
        grid-template-columns: 1fr;
    }

    .footer-bottom {
        flex-direction: column;
        align-items: flex-start;
    }
}