* {
        margin: 0;
        padding: 0;
        box-sizing: border-box;
    }

    body {
        font-family: 'Microsoft YaHei', Arial, sans-serif;
        background-color: #f5f7fa;
        color: #333;
        line-height: 1.6;
    }


    h1 {
        text-align: center;
        margin-bottom: 30px;
        color: #2c3e50;
        font-size: 24px;
    }

    .question-item {
        background-color: #fff;
        border-radius: 6px;
        box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
        padding: 15px;
        margin-bottom: 10px;
        transition: all 0.3s ease;
        border-left: 3px solid #3498db;
    }

    .question-item:hover {
        box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
        background-color: #f9f9f9;
    }

    .question-header {
        display: flex;
        justify-content: space-between;
        align-items: center;
        margin-bottom: 10px;
        font-size: 14px;
    }

    .question-number {
        font-size: 0.8rem;
        font-weight: 600;
        color: #3498db;
        background-color: #ebf5fb;
        padding: 2px 8px;
        border-radius: 10px;
        display: flex;
        flex-direction: row;
        flex-wrap: nowrap;
        justify-content: center;
        align-items: center;
    }

    .question-type {
        margin-left: 10px;
        font-size: 0.8rem;
        font-weight: 600;
        color: #3498db;
        background-color: #ebf5fb;
        padding: 2px 8px;
        border-radius: 10px;
        display: inline-block;
    }

    .question-type.single {
        background-color: #3498db;
        color: #fff;
    }

    .question-type.multi {
        background-color: #9b59b6;
        color: #fff;
    }

    .question-type.judge {
        background-color: #e74c3c;
        color: #fff;
    }

    .question-type.fill {
        background-color: #1abc9c;
        color: #fff;
    }

    .question-type.programming {
        background-color: #f39c12;
        color: #fff;
    }

    .question-stats {
        display: flex;
        gap: 10px;
        font-size: 12px;
        color: #666;
    }

    .stat-item {
        display: flex;
        align-items: center;
        gap: 3px;
    }

    .accuracy {
        color: #27ae60;
        font-weight: 500;
    }

    .question-content {
        margin-bottom: 10px;
        line-height: 1.6;
        /* color: #333; */
        font-size: 1.2rem;
    }

    .knowledge-points {
        display: flex;
        flex-wrap: wrap;
        gap: 6px;
        margin-top: 10px;
    }

    .knowledge-tag {
        background-color: #f0f4f8;
        color: #3498db;
        padding: 2px 8px;
        border-radius: 12px;
        font-size: 11px;
        cursor: pointer;
        transition: all 0.3s ease;
    }

    .knowledge-tag:hover {
        background-color: #3498db;
        color: #fff;
    }

    .loading-container {
        display: flex;
        justify-content: center;
        align-items: center;
        height: 300px;
    }

    .empty-container {
        text-align: center;
        padding: 80px 20px;
        color: #999;
        background-color: #fff;
        border-radius: 8px;
        box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
        margin: 20px 0;
    }

    .empty-container i {
        font-size: 64px;
        margin-bottom: 20px;
        color: #e0e0e0;
        transition: all 0.3s ease;
    }

    .empty-container:hover i {
        color: #3498db;
        transform: scale(1.1);
    }

    .empty-container p {
        font-size: 16px;
        margin-bottom: 10px;
        color: #666;
    }

    .empty-container .empty-tip {
        font-size: 14px;
        color: #999;
    }

    .pagination-container {
        display: flex;
        justify-content: center;
    }

    .pagination-container .pagination {
        display: -ms-flexbox;
        display: flex;
        padding-left: 0;
        list-style: none;
        border-radius: .25rem;
        flex-wrap: wrap;
        justify-content: center;
        align-items: center;
        flex-direction: row;
    }

    .pagination li {
        padding: 5px 10px;
        background: #dbdbdb;
        border-radius: 5px;
        margin: 5px;
        cursor: pointer;
        text-decoration: none;
    }

    .pagination li.active {
        background-color: #3498db;
        color: #fff;
        cursor: not-allowed;
    }


    @media (max-width: 768px) {
        h1 {
            font-size: 20px;
        }

        .question-header {
            flex-direction: column;
            align-items: flex-start;
            gap: 10px;
        }

        .question-stats {
            width: 100%;
            justify-content: space-between;
        }
    }

    .question-category .nav {
        margin: 10px 20px;
        background-color: #fff;
        border-radius: 8px;
        padding: 12px 15px;
        box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
    }

    .breadcrumb {
        display: flex;
        align-items: center;
        flex-wrap: wrap;
        gap: 8px;
        font-size: 14px;
        margin-bottom: 0;
    }

    .breadcrumb-item {
        display: flex;
        align-items: center;
        gap: 8px;
    }

    .breadcrumb-item:not(:last-child)::after {
        content: '>';
        color: #999;
        margin-left: 4px;
    }

    .breadcrumb-item a {
        color: #666;
        text-decoration: none;
        transition: color 0.3s ease;
    }

    .breadcrumb-item a:hover {
        color: #3498db;
    }

    .breadcrumb-item:last-child a {
        color: #3498db;
        font-weight: 500;
    }

    .question-category .question-list {
        margin: 20px;
    }

    .sub-category-section {
        margin: 20px;
        background-color: #fff;
        border-radius: 8px;
        box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
        padding: 15px;
    }

    .sub-category-title {
        font-size: 16px;
        font-weight: 600;
        color: #2c3e50;
        margin-bottom: 15px;
        padding-bottom: 10px;
        border-bottom: 1px solid #eaeaea;
        display: flex;
        align-items: center;
        gap: 8px;
    }

    .sub-category-title::before {
        content: '';
        width: 4px;
        height: 16px;
        background-color: #3498db;
        border-radius: 2px;
    }

    .sub-category-list {
        display: flex;
        gap: 10px;
        flex-direction: row;
        flex-wrap: wrap;
    }

    .sub-category-item {
        background-color: #fff;
        border: 1px solid #eaeaea;
        border-left: 3px solid #3498db;
        border-radius: 6px;
        padding: 10px 15px;
        transition: all 0.3s ease;
        cursor: pointer;
        /* flex: 1 1 calc(33.333% - 7px);
        min-width: 200px; */
    }

    .sub-category-item:hover {
        box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
        transform: translateY(-1px);
    }

    .sub-category-item a {
        color: #333;
        text-decoration: none;
        font-size: 14px;
        display: block;
        width: 100%;
    }

    .sub-category-item:hover a {
        color: #3498db;
    }