聚焦式文档树

文档树变一下显示效果，不会有任何性能的提升

/* 隐藏非聚焦的文档树 */
.file-tree ul ul li:not(:has(+ul .b3-list-item--focus)) {
    display: none;
}
/*显示聚焦的直接子文档*/
.file-tree .b3-list-item--focus+ul>li {
    display: flex!important;
}
/* 显示聚焦本身 */
.file-tree .b3-list-item--focus {
    display: flex!important;
}

/* 显示聚焦但不打开的同级文档 */
.file-tree ul li:has(~li.b3-list-item--focus):not(:has(~li.b3-list-item--focus+ul)) {
    display: flex!important;
}

.file-tree ul li.b3-list-item--focus:not(:has(+ul))~li {
    display: flex!important;
}

/*显示聚焦块下方的提示条*/
.file-tree .b3-list-item--focus+ul:before {
    content: "";
    border-top: 2px solid var(--b3-theme-background-light);
    width: 100%;
    display: block;
    top: 2px;
    position: relative;
}
/*显示聚焦但不打开上方的提示条*/
.file-tree ul ul:has(>li.b3-list-item--focus):not(:has(>li.b3-list-item--focus+ul)):before {
    content: "";
    border-top: 2px solid var(--b3-theme-background-light);
    width: 100%;
    display: block;
    top: 2px;
    position: relative;
}

/* 极大缩小缩进 */
.file-tree ul ul ul{
    margin-left: -1.2em;
}