更改Element-表格的边框样式，覆盖Element-Ui默认样式

.el-table--border:after,
.el-table--group:after,
.el-table:before {
    background-color: red;
}
.el-table--border,
.el-table--group {
    border-color: red;
}
.el-table td,
.el-table th.is-leaf {
        border-bottom: 1px solid red;
}
.el-table--border th,
.el-table--border th.gutter:last-of-type {
        border-bottom: 1px solid red;
}
.el-table--border td,
.el-table--border th {
        border-right: 1px solid red;
}