.mobile-nav-toggle, .mobile-nav-backdrop { display: none; }

/* 内置浏览器窄面板使用可收起导航，不占用卡片的固定宽度。 */
@media (max-width: 760px) {
    .mobile-nav-toggle { display: grid; place-items: center; position: fixed; top: 12px; left: 12px; z-index: 102; width: 36px; height: 36px; border-radius: 4px; background: var(--color-primary); color: var(--color-text-white); }
    .mobile-nav-toggle svg { width: 20px; height: 20px; }
    .mobile-nav-backdrop { display: block; position: fixed; inset: 0; z-index: 100; background: rgba(0, 0, 0, .35); }
    .app-container > .sidebar { position: fixed; inset: 0 auto 0 0; z-index: 101; width: min(var(--sidebar-width), 85%); visibility: hidden; transform: translateX(-100%); }
    .navigation-open .app-container > .sidebar { visibility: visible; transform: translateX(0); }
    .navigation-open .sidebar-brand { padding-left: 60px; min-height: 60px; }
}

.sidebar {
    width: var(--sidebar-width);
    height: 100%;
    background: var(--color-bg-dark);
    display: flex;
    flex-direction: column;
    flex-shrink: 0;
}

.sidebar-brand {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: var(--spacing-4) var(--spacing-5);
}

.sidebar-brand-icon {
    width: 24px;
    height: 24px;
    color: var(--color-primary);
}

.sidebar-brand-text {
    color: var(--color-text-white);
    font-size: var(--font-size-lg);
    font-weight: 700;
}

.sidebar-nav {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 2px;
    padding: var(--spacing-2);
    overflow-y: auto;
}

.nav-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-3);
    padding: 10px var(--spacing-3);
    border-radius: var(--radius-sm);
    color: var(--color-text-muted);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.nav-item:hover {
    background: rgba(255, 255, 255, 0.05);
    color: var(--color-text-white);
}

.nav-item.active {
    background: var(--color-primary);
    color: var(--color-text-white);
}

.nav-item-icon {
    width: 20px;
    height: 20px;
    flex-shrink: 0;
}

.nav-item-text {
    font-size: var(--font-size-base);
}

/* 二级菜单分组 */
.nav-group {
    display: flex;
    flex-direction: column;
}

.nav-group-header {
    display: flex;
    align-items: center;
    gap: var(--spacing-3);
    padding: 10px var(--spacing-3);
    border-radius: var(--radius-sm);
    color: var(--color-text-muted);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.nav-group-header:hover {
    background: rgba(255, 255, 255, 0.05);
    color: var(--color-text-white);
}

.nav-group-arrow {
    width: 14px;
    height: 14px;
    margin-left: auto;
    transition: transform var(--transition-fast);
}

.nav-group.expanded .nav-group-arrow {
    transform: rotate(90deg);
}

.nav-group-items {
    display: flex;
    flex-direction: column;
    gap: 2px;
    padding-left: var(--spacing-4);
}

.nav-item.sub {
    padding: 8px var(--spacing-3);
    font-size: var(--font-size-sm);
}

.nav-item.sub .nav-item-text {
    font-size: var(--font-size-sm);
}

.sidebar-divider {
    height: 1px;
    background: var(--color-border);
    margin: 0;
}

.sidebar-bottom {
    background: var(--color-bg-darker);
    border-top: 1px solid #2e3154;
    padding: var(--spacing-4);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-3);
}

.user-info {
    display: flex;
    align-items: center;
    gap: 10px;
}

.user-avatar {
    width: var(--avatar-size-lg);
    height: var(--avatar-size-lg);
    background: var(--color-primary);
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-text-white);
    font-size: var(--font-size-md);
    font-weight: 600;
    flex-shrink: 0;
}

.user-details {
    flex: 1;
    min-width: 0;
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.user-name {
    color: var(--color-text-white);
    font-size: var(--font-size-base);
    font-weight: 500;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.user-email {
    color: var(--color-text-muted);
    font-size: var(--font-size-sm);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.sidebar-login-btn {
    width: 100%;
    height: 40px;
    background: var(--color-primary);
    color: var(--color-text-white);
    border-radius: var(--radius-sm);
    font-size: var(--font-size-base);
    font-weight: 500;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background var(--transition-fast);
}

.sidebar-login-btn:hover {
    background: #5558e3;
}

.sidebar-logout-btn {
    width: 100%;
    height: 36px;
    background: rgba(255, 68, 68, 0.15);
    color: var(--color-error);
    border-radius: var(--radius-sm);
    font-size: var(--font-size-sm);
    font-weight: 500;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-2);
    transition: background var(--transition-fast);
}

.sidebar-logout-btn:hover {
    background: rgba(255, 68, 68, 0.25);
}