header {
    background: linear-gradient(90deg, #2c3e50, #4a6491);
    color: white;
    /* 调整header->padding: */
    padding: 10px 10px;
    text-align: center;
}
.search-container {
    /* 调整search-container->padding: */
    padding: 5px 15px;
    /* 调整search-container->margin: */
    margin: 10px auto 10px;
    background: #fff;
    border-radius: 50px;
    max-width: 600px;
    display: flex;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.15);
}
.search-container input {
    flex: 1;
    border: none;
    /* 调整.search-container input-> padding */
    padding: 10px;
    font-size: 16px;
    outline: none;
    background: transparent;
}
.search-container button {
    background: transparent;
    border: none;
    color: #4a6491;
    cursor: pointer;
    font-size: 20px;
    /* 调整.search-container button-> padding */
    padding: 0 10px;
    transition: transform 0.3s;
}
.link-icon {
    height: 70px;
    /* 调整.link-icon-> width */
    width: 90px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #4a6491, #2c3e50);
    color: white;
    font-size: 2.2rem;
    /* 调整.link-icon-> border-radius */
    border-radius: 20%;
    margin-bottom: 15px;
    transition: transform 0.3s;
}
.tree-leaf {
    /* 调整tree-leaf.padding: top right down left; 下级目录靠左位置 */
    padding: 8px 15px 8px 10px;
    cursor: pointer;
    border-radius: 6px;
    display: block;
    color: #555;
    transition: all 0.3s;
    font-size: 1.05rem;
}