.bim-engine-wrapper {
    position: relative;
    width: 100%;
    height: 100%;
    font-family: sans-serif;
    box-sizing: border-box;
    overflow: hidden;
    background: linear-gradient(to bottom, rgb(214, 224, 235), rgb(246, 250, 255));
}


/* ... (中间代码不变) ... */

.bim-engine-opt-btn-container {
    z-index: 100;
}

/* 构造树按钮 */
.bim-construct-tree-btn {
    position: absolute;
    top: 20px;
    left: 20px !important;
    z-index: 100;
}