* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
:root {
    --main: #409eff;
    --light: #f5f7fa;
    --radius: 16px;
    --shadow: 0 8px 24px rgba(0,0,0,0.06);
}
.tool-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 40px 20px;
}
.tool-title {
    font-size: 32px;
    font-weight: 700;
    text-align: center;
    margin-bottom: 10px;
}
.tool-desc {
    text-align: center;
    color: #666;
    margin-bottom: 40px;
    font-size: 15px;
}

/* 搜索筛选栏 */
.search-bar {
    background: #fff;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 24px;
    margin-bottom: 20px;
    display: flex;
    flex-wrap: wrap;
    gap: 16px;
    align-items: center;
}
.bar-item {
    display: flex;
    align-items: center;
    gap: 10px;
    flex: 1;
    min-width: 220px;
}
.bar-item label {
    font-size: 14px;
    color: #333;
    white-space: nowrap;
}
.bar-input,
.bar-select {
    width: 100%;
    height: 44px;
    padding: 0 14px;
    border: 1px solid #e5e7eb;
    border-radius: 10px;
    outline: none;
    font-size: 14px;
}
.bar-input:focus,
.bar-select:focus {
    border-color: var(--main);
    box-shadow: 0 0 0 3px rgba(64,158,255,0.1);
}
.btn {
    height: 44px;
    padding: 0 22px;
    border-radius: 10px;
    border: none;
    background: var(--main);
    color: #fff;
    font-size: 14px;
    cursor: pointer;
    transition: 0.2s;
}
.btn:hover {
    background: #338eff;
}
.btn-outline {
    background: #fff;
    color: var(--main);
    border: 1px solid var(--main);
}

/* 多类别选择栏 单独一行 */
.multi-cate-wrap {
    background: #fff;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 20px 24px;
    margin-bottom: 20px;
}
.multi-title {
    font-size: 15px;
    color: #333;
    margin-bottom: 12px;
    font-weight: 500;
}
.cate-check-wrap {
    display: flex;
    flex-wrap: wrap;
    gap: 14px;
}
.cate-check-item {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 14px;
    cursor: pointer;
}
.cate-check-item input{
    appearance: checkbox !important;
}
/* 随机出题控制栏 单独一行 */
.random-bar {
    background: #fff;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 20px 24px;
    margin-bottom: 30px;
    display: flex;
    flex-wrap: wrap;
    gap: 16px;
    align-items: center;
}
.random-num {
    width: 100px;
    height: 44px;
    padding: 0 10px;
    border: 1px solid #e5e7eb;
    border-radius: 10px;
    outline: none;
    font-size: 14px;
}

/* 题目展示 */
.question-box {
    background: #fff;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 30px;
}
.question-title {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 20px;
    color: #222;
    padding-bottom: 12px;
    border-bottom: 1px solid #f2f2f2;
}
.question-list {
    display: flex;
    flex-direction: column;
    gap: 18px;
}
.question-item {
    padding: 18px;
    background: var(--light);
    border-radius: 12px;
}
.question-q {
    font-weight: 500;
    color: #222;
    margin-bottom: 8px;
    font-size: 15px;
}
.question-a {
    font-size: 14px;
    color: #555;
    line-height: 1.6;
}
.empty {
    text-align: center;
    padding: 60px 20px;
    color: #999;
}

@media (max-width:768px) {
    .search-bar {
        flex-direction: column;
        align-items: stretch;
    }
    .random-bar {
        flex-direction: column;
        align-items: stretch;
    }
    .question-box {
        padding: 20px;
    }
}