单击 [Bootstrap 4] 时如何更改按钮的蓝色轮廓颜色

gar*_*lle 2 html css twitter-bootstrap

如果我单击以下按钮,则会出现蓝色轮廓:

<button onclick="window.location.href='/Downloads'" type="button" class="btn btn-lg btn-primary" style="background-color:green;border-color:green">Download</button>
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我怎样才能改变这种颜色?

Sve*_*rth 5

.btn {
  outline-color: red;
}
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或仅在单击按钮时显式更改它:

.btn:active {
  outline-color: red;
}
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