.tool-container {
    max-width: 1100px;
    margin: 30px auto;
    padding: 0 20px;
}
.tool-title {
    font-size: 26px;
    font-weight: bold;
    text-align: center;
    margin-bottom: 10px;
    color: #2c3e50;
}
.tool-desc {
    text-align: center;
    color: #7f8c8d;
    margin-bottom: 30px;
    font-size: 15px;
}
/* 搜索框样式 */
.search-box {
    background: #fff;
    padding: 16px 20px;
    border-radius: 16px;
    margin-bottom: 25px;
    /*box-shadow: 0 4px 15px rgba(0,0,0,0.06);*/
    /*border: 1px solid #eef2f7;*/
    position: relative;
}
.search-input {
    width: 100%;
    padding: 14px 20px;
    border: 1px solid #e1e8f0;
    border-radius: 12px;
    font-size: 15px;
    outline: none;
    transition: all 0.3s ease;
    background: #f9fafb;
}
.search-input:focus {
    border-color: #3498db;
    background: #fff;
    box-shadow: 0 0 0 4px rgba(52, 152, 219, 0.15);
}
.search-input::placeholder {
    color: #a0aec0;
}
/* 筛选标签通用样式 */
.filter-tabs {
    display: flex;
    gap: 12px;
    margin-bottom: 30px;
    flex-wrap: wrap;
}
.filter-tab {
    padding: 10px 22px;
    background: #f1f5f9;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.2s;
    font-weight: 500;
}
.filter-tab.active {
    background: #3498db;
    color: #fff;
}
/* 课程标题层级 */
.course-title {
    font-size: 22px;
    font-weight: 700;
    color: #243b55;
    margin: 35px 0 15px;
    padding-bottom: 10px;
    border-bottom: 2px solid #3498db;
}
/* 大知识点标题 */
.big-knowledge-title {
    font-size: 18px;
    font-weight: 600;
    color: #2c3e50;
    background: #f5f7fa;
    border-radius: 8px;
    padding: 10px 16px;
    margin: 20px 0 12px;
}
/* 知识点卡片 */
.knowledge-card {
    background: #ffffff;
    border-radius: 10px;
    padding: 18px 22px;
    box-shadow: 0 1px 8px rgba(0,0,0,0.08);
    margin-bottom: 12px;
}
.knowledge-top {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 15px;
}
.knowledge-name {
    font-size: 16px;
    font-weight: 600;
    color: #222;
}
/* 难度标签 */
.tag-easy {
    background-color: #e8f5e9;
    color: #2e7d32;
}
.tag-middle {
    background-color: #fff8e1;
    color: #f57c00;
}
.tag-hard {
    background-color: #ffebee;
    color: #d32f2f;
}
.diff-tag {
    font-size: 12px;
    padding: 2px 10px;
    border-radius: 20px;
    font-weight: 500;
}
/* 知识点、考点分块 */
.block-item {
    margin-bottom: 12px;
}
.block-title {
    display: inline-block;
    font-size: 14px;
    font-weight: 600;
    color: #3498db;
    margin-bottom: 6px;
    border-left: 3px solid #3498db;
    padding-left: 8px;
}
.block-content {
    font-size: 14px;
    color: #555;
    line-height: 1.8;
    padding-left: 11px;
}
/* 空数据提示 */
.empty-tip {
    text-align: center;
    padding: 60px 0;
    color: #999;
    font-size: 15px;
}