.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);
}