/* 左侧边栏 */
.sidebar {
    width: 260px;
    background: linear-gradient(180deg, #667eea 0%, #764ba2 100%);
    display: flex;
    flex-direction: column;
    padding: 30px 0;
    flex-shrink: 0;
}

.sidebar-title {
    color: rgba(255, 255, 255, 0.7);
    font-size: 13px;
    letter-spacing: 2px;
    padding: 0 24px;
    margin-bottom: 16px;
}

.nav-list {
    list-style: none;
}

.nav-item {
    padding: 14px 24px;
    color: rgba(255, 255, 255, 0.75);
    font-size: 15px;
    cursor: pointer;
    transition: all 0.25s ease;
    display: flex;
    align-items: center;
    gap: 10px;
}

.nav-item:hover {
    background: rgba(255, 255, 255, 0.12);
    color: #fff;
}

.nav-item.active {
    background: rgba(255, 255, 255, 0.18);
    color: #fff;
    font-weight: 500;
}

.nav-item .icon {
    width: 20px;
    height: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 16px;
}

/* 一级菜单容器 */
.nav-parent {
    list-style: none;
}

.nav-caret {
    margin-left: auto;
    font-size: 12px;
    transition: transform 0.25s ease;
}

.nav-item[data-group].open .nav-caret {
    transform: rotate(90deg);
}

/* 子菜单 */
.nav-submenu {
    list-style: none;
    background: rgba(0, 0, 0, 0.12);
    padding: 4px 0;
}

.nav-submenu[hidden] {
    display: none;
}

.nav-subitem {
    padding: 12px 24px 12px 54px;
    font-size: 14px;
}