.admin-container {
    display: flex;
    height: 100vh;
    overflow: hidden;
}

.sidebar {
    width: 220px;
    background-color: #001529;
    color: #fff;
    display: flex;
    flex-direction: column;
    transition: width 0.3s;
}

.sidebar.collapsed {
    width: 60px;
}

.sidebar-header {
    padding: 18px 20px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
    background: linear-gradient(180deg, rgba(24, 144, 255, 0.08) 0%, transparent 100%);
}

.sidebar-header .logo {
    display: flex;
    align-items: center;
    font-size: 17px;
    font-weight: 700;
    letter-spacing: 0.5px;
}

.sidebar-header .logo .icon {
    font-size: 26px;
    margin-right: 10px;
    color: #1890ff;
    filter: drop-shadow(0 0 6px rgba(24, 144, 255, 0.4));
}

.sidebar.collapsed .sidebar-header .logo span {
    display: none;
}

.sidebar-nav {
    flex: 1;
    overflow-y: auto;
    padding-top: 10px;
}

.nav-list {
    list-style: none;
    padding: 0 8px;
}

.nav-item {
    margin-bottom: 2px;
    border-radius: 6px;
}

.nav-item a.nav-link {
    display: flex;
    align-items: center;
    padding: 12px 16px;
    color: rgba(255, 255, 255, 0.95);
    font-size: 15px;
    font-weight: 500;
    border-radius: 6px;
    transition: all 0.25s ease;
    position: relative;
}

.nav-item a.nav-link:hover {
    background-color: rgba(24, 144, 255, 0.15);
    color: #fff;
}

.nav-item.active > a.nav-link {
    background: linear-gradient(135deg, rgba(24, 144, 255, 0.25) 0%, rgba(24, 144, 255, 0.1) 100%);
    color: #fff;
    font-weight: 600;
}

.nav-item.active > a.nav-link::before {
    content: '';
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 3px;
    height: 60%;
    background: #1890ff;
    border-radius: 0 3px 3px 0;
}

.nav-item a.nav-link .icon {
    font-size: 20px;
    margin-right: 12px;
    width: 22px;
    text-align: center;
    flex-shrink: 0;
}

.nav-item a.nav-link:hover .icon {
    color: #1890ff;
}

.nav-item.active a.nav-link .icon {
    color: #1890ff;
}

.nav-item a.nav-link .arrow {
    margin-left: auto;
    font-size: 12px;
    transition: transform 0.3s;
    opacity: 0.6;
}

.nav-item.active a.nav-link .arrow {
    transform: rotate(180deg);
    opacity: 1;
}

.sidebar.collapsed .nav-item a.nav-link span,
.sidebar.collapsed .nav-item a.nav-link .arrow {
    display: none;
}

.sub-nav {
    display: none;
    list-style: none;
    background-color: rgba(0, 0, 0, 0.15);
    border-radius: 0 0 6px 6px;
    margin-top: 2px;
    padding: 4px 0;
}

.nav-item.active .sub-nav {
    display: block;
}

.sub-nav li a {
    display: block;
    padding: 9px 16px 9px 50px;
    color: rgba(255, 255, 255, 0.65);
    font-size: 13px;
    font-weight: 400;
    transition: all 0.25s ease;
    position: relative;
}

.sub-nav li a::before {
    content: '';
    position: absolute;
    left: 30px;
    top: 50%;
    transform: translateY(-50%);
    width: 4px;
    height: 4px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.25);
    transition: all 0.25s ease;
}

.sub-nav li a:hover {
    background-color: rgba(24, 144, 255, 0.1);
    color: #fff;
    padding-left: 56px;
}

.sub-nav li a:hover::before {
    background: #1890ff;
    width: 6px;
    height: 6px;
}

.sub-nav li a.active {
    color: #1890ff;
    font-weight: 500;
}

.sidebar.collapsed .sub-nav {
    display: none;
}

.main-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.top-header {
    height: 60px;
    background-color: #fff;
    border-bottom: 1px solid #f0f0f0;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 20px;
    flex-shrink: 0;
}

.header-left {
    display: flex;
    align-items: center;
}

.sidebar-toggle {
    background: none;
    border: none;
    font-size: 20px;
    cursor: pointer;
    padding: 10px;
    color: #666;
    margin-right: 20px;
}

.sidebar-toggle:hover {
    color: #1890ff;
}

.breadcrumb {
    display: flex;
    align-items: center;
    font-size: 14px;
    color: #666;
}

.breadcrumb a {
    color: #666;
}

.breadcrumb a:hover {
    color: #1890ff;
}

.breadcrumb .icon-arrow-right {
    margin: 0 8px;
    font-size: 12px;
}

.header-right {
    display: flex;
    align-items: center;
}

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

.user-name {
    margin-right: 20px;
    font-size: 14px;
}

.logout-btn {
    padding: 6px 16px;
    background-color: #f5f5f5;
    border-radius: 4px;
    font-size: 13px;
}

.logout-btn:hover {
    background-color: #fff2f0;
    color: #ff4d4f;
}

.page-content {
    flex: 1;
    overflow-y: auto;
    padding: 20px;
    background-color: #f5f7fa;
}

@media (max-width: 768px) {
    .sidebar {
        position: fixed;
        left: 0;
        top: 0;
        height: 100vh;
        z-index: 100;
    }
    
    .sidebar.collapsed {
        left: -220px;
    }
    
    .main-content {
        margin-left: 0;
    }
}