CSS 响应三角形宽度

CSS Responsive Triangle Width

真的很简单的问题,我想知道如何使三角形宽度(在 css 中用下面的代码制作)等于页面宽度,这样当浏览器调整大小时三角形也会调整。

我的代码,到目前为止

.triangle {
    color: crimson;
    width: 0;
    height: 0;
    margin-top: 30%;
    border-top: 100px solid crimson;
    border-left: 100px solid transparent;
    border-right: 100px solid transparent;
}
.triangle {
    color: crimson;
    width: 0;
    height: 0;
    margin-top: 30%;
    border-top: 100px solid crimson;
    border-left: 50vw solid transparent; /* check border size here! */
    border-right: 50vw solid transparent; /* and here! */
}

Sample fiddle.

Read more on CSS3 vh/vw units.

Browser support is not an issue.