/**
 * 全站统一顶栏导航 + 移动端抽屉
 * 依赖 body.has-site-nav（可选 .page-theme-dark / .page-theme-admin）
 */

:root {
    --site-nav-h: 56px;
    --site-nav-bg: rgba(255, 255, 255, 0.12);
    --site-nav-border: rgba(255, 255, 255, 0.18);
    --site-nav-link: rgba(255, 255, 255, 0.88);
    --site-nav-link-hover-bg: rgba(255, 255, 255, 0.18);
    --site-nav-active-bg: rgba(102, 126, 234, 0.45);
    --site-nav-shadow: 0 8px 32px rgba(31, 38, 135, 0.18);
}

.page-theme-dark {
    --site-nav-bg: rgba(17, 24, 39, 0.92);
    --site-nav-border: rgba(55, 65, 81, 0.9);
    --site-nav-link: rgba(229, 231, 235, 0.95);
    --site-nav-link-hover-bg: rgba(55, 65, 81, 0.95);
    --site-nav-active-bg: rgba(37, 99, 235, 0.55);
}

.page-theme-admin {
    --site-nav-bg: rgba(18, 26, 47, 0.92);
    --site-nav-border: rgba(148, 163, 184, 0.28);
    --site-nav-link: #e5e7eb;
    --site-nav-link-hover-bg: rgba(79, 124, 255, 0.22);
    --site-nav-active-bg: rgba(79, 124, 255, 0.42);
    --site-nav-shadow: 0 8px 28px rgba(2, 6, 23, 0.45);
}

.site-nav {
    position: sticky;
    top: 0;
    z-index: 1000;
    width: 100%;
    backdrop-filter: blur(18px);
    -webkit-backdrop-filter: blur(18px);
    background: var(--site-nav-bg);
    border-bottom: 1px solid var(--site-nav-border);
    box-shadow: var(--site-nav-shadow);
    padding-top: env(safe-area-inset-top);
}

.site-nav-inner {
    max-width: 1480px;
    margin: 0 auto;
    padding: 10px 16px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    min-height: var(--site-nav-h);
    box-sizing: border-box;
}

.site-nav-brand {
    flex-shrink: 0;
    font-weight: 700;
    font-size: 1.05rem;
    color: var(--site-nav-link);
    text-decoration: none;
    letter-spacing: 0.02em;
    white-space: nowrap;
}

.site-nav-brand:hover {
    opacity: 0.92;
}

.site-nav-toggle {
    display: none;
    align-items: center;
    justify-content: center;
    width: 44px;
    height: 44px;
    padding: 0;
    border: 1px solid var(--site-nav-border);
    border-radius: 12px;
    background: var(--site-nav-link-hover-bg);
    color: var(--site-nav-link);
    font-size: 1.35rem;
    line-height: 1;
    cursor: pointer;
    flex-shrink: 0;
}

.site-nav-toggle:focus-visible {
    outline: 2px solid rgba(102, 126, 234, 0.8);
    outline-offset: 2px;
}

.site-nav-menu {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: flex-end;
    gap: 6px;
    flex: 1;
    min-width: 0;
}

.site-nav-link {
    display: inline-flex;
    align-items: center;
    padding: 8px 12px;
    border-radius: 10px;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--site-nav-link);
    text-decoration: none;
    background: transparent;
    border: none;
    transition: background 0.2s ease, color 0.2s ease;
    white-space: nowrap;
}

.site-nav-link:hover {
    background: var(--site-nav-link-hover-bg);
}

.site-nav-link.is-active {
    background: var(--site-nav-active-bg);
    font-weight: 600;
}

.site-nav-link.site-nav-link--danger {
    background: rgba(239, 68, 68, 0.22);
    color: #fecaca;
}

.page-theme-admin .site-nav-link.site-nav-link--danger {
    color: #fecaca;
    background: rgba(239, 68, 68, 0.22);
}

.site-nav-backdrop {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.45);
    z-index: 999;
    opacity: 0;
    transition: opacity 0.25s ease;
}

.site-nav.is-open .site-nav-backdrop {
    display: block;
    opacity: 1;
}

@media (max-width: 1080px) {
    .site-nav-toggle {
        display: inline-flex;
    }

    .site-nav-menu {
        display: none;
        position: fixed;
        left: 0;
        right: 0;
        top: calc(env(safe-area-inset-top) + var(--site-nav-h) + 8px);
        margin: 0 12px;
        padding: 12px;
        flex-direction: column;
        align-items: stretch;
        flex-wrap: nowrap;
        max-height: min(72vh, calc(100dvh - var(--site-nav-h) - 24px));
        overflow-y: auto;
        border-radius: 16px;
        border: 1px solid var(--site-nav-border);
        background: var(--site-nav-bg);
        backdrop-filter: blur(20px);
        -webkit-backdrop-filter: blur(20px);
        box-shadow: 0 16px 48px rgba(0, 0, 0, 0.35);
        z-index: 1001;
    }

    .site-nav.is-open .site-nav-menu {
        display: flex;
    }

    .site-nav-link {
        justify-content: flex-start;
        white-space: normal;
        padding: 12px 14px;
    }

    .site-nav-inner {
        padding-left: max(12px, env(safe-area-inset-left));
        padding-right: max(12px, env(safe-area-inset-right));
    }
}

/* 页面主区域：移动端留白与安全区 */
.has-site-nav .container {
    padding-left: max(16px, env(safe-area-inset-left));
    padding-right: max(16px, env(safe-area-inset-right));
}

@media (max-width: 600px) {
    .has-site-nav .container {
        padding-left: max(12px, env(safe-area-inset-left));
        padding-right: max(12px, env(safe-area-inset-right));
    }
}

.page-theme-admin.has-site-nav .container {
    padding-bottom: env(safe-area-inset-bottom);
}