/* 全局 */
html, body {
    margin: 0;
    padding: 0;
    height: 100%;
    overflow: hidden;
}

#app {
    display: flex;
    height: 100vh;
    overflow: hidden;
}

/* 左侧 */
.left {
    width: 320px;
    background: #fff;
    border-right: 1px solid #eee;
    overflow-y: auto;
}

/* 右侧预览区 */
.right#previewBox {
    flex: 1;
    height: 100%;        /* 核心 */
    overflow: hidden;    /* 核心 */
    position: relative;
}

/* 标题固定 */
.preview-title {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    padding: 12px 15px;
    background: #fff;
    border-bottom: 1px solid #eee;
    z-index: 10;
}

/* 内容区域：强制高度 + 滚动 */
.preview-content-wrapper {
    position: absolute;
    top: 46px; /* 标题高度 */
    left: 0;
    right: 0;
    bottom: 0;
    overflow-y: scroll !important; /* 强制滚动 */
    padding: 15px;
}

/* 复制按钮 */
.copy-btn {
    position: fixed;
    top: 52px;
    right: 60px;
    z-index: 999;
    padding: 4px 10px;
    font-size: 16px;
    background: #409eff;
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
}
.copy-btn:hover {
    background: #66b1ff;
}

/* 内容 */
.preview-content {
    line-height: 1.6;
}

/* 空状态 */
.empty {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100%;
    color: #999;
}

  /* 让 loading 整体垂直水平居中 */
        .preview-loading {
        display: flex;
        align-items: center;
        justify-content: center;
        }
        /* 加大 loading 文字字体 */
        .preview-loading .el-loading-text {
        font-size: 18px; /* 你可以改成 20px/22px 更大 */
        margin-top: 10px;
        }
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: "Microsoft YaHei", sans-serif;
        }
        html, body {
            height: 100%;
            background: #f5f7fa;
            padding: 20px;
        }
        #app {
            display: flex;
            height: 100%;
            gap: 20px;
        }
        .left {
            width: 450px;
            display: flex;
            flex-direction: column;
            gap: 20px;
            height: 100%;
        }
        .tree-card {
            background: white;
            border-radius: 16px;
            box-shadow: 0 8px 20px rgba(0,0,0,0.07);
            padding: 20px;
            flex: 1;
            overflow-y: auto;
        }
        .tree-title {
            font-size: 18px;
            margin-bottom: 15px;
            color: #2c3e50;
        }
        .down-card {
            background: white;
            border-radius: 16px;
            box-shadow: 0 8px 20px rgba(0,0,0,0.07);
            padding: 30px;
            text-align: center;
        }
        .down-icon {
            font-size: 60px;
            margin-bottom: 15px;
        }
        .down-title {
            font-size: 20px;
            color: #2c3e50;
            margin-bottom: 10px;
        }
        .down-desc {
            color: #7f8c8d;
            margin-bottom: 20px;
            font-size: 14px;
        }
        .down-btn {
            display: inline-block;
            padding: 12px 30px;
            background: #2d8cf0;
            color: white;
            border-radius: 8px;
            text-decoration: none;
            font-weight: bold;
            transition: 0.3s;
        }
        .down-btn:hover {
            background: #1b79d8;
            transform: translateY(-2px);
        }
        .right {
            flex: 1;
            background: white;
            border-radius: 16px;
            box-shadow: 0 8px 20px rgba(0,0,0,0.07);
            padding: 30px;
            overflow-y: auto;
            height: 100%;
        }
        .preview-title {
            font-size: 20px;
            color: #2c3e50;
            margin-bottom: 20px;
            padding-bottom: 10px;
            border-bottom: 1px solid #eee;
        }
        .preview-content {
            line-height: 1.9;
            color: #34495e;
            font-size: 15px;
            white-space: pre-wrap;
        }
        .empty {
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            height: 100%;
            color: #999;
            font-size: 16px;
            gap: 10px;
        }
        .empty i {
            font-size: 60px;
        }
        /* 自定义展开图标样式 */
        .tree-expand-icon {
            display: inline-block;
            width: 14px;
            height: 14px;
            text-align: center;
            line-height: 14px;
            margin-right: 4px;
            cursor: pointer;
            color: #666;
            font-size: 12px;
            transition: transform 0.2s;
        }
        .tree-expand-icon.expanded {
            transform: rotate(90deg);
        }
        /* 去掉 el-tree 所有展开收缩小三角图标 */
        .el-tree-node__expand-icon {
        display: none !important;
        }