我在制作自定义单选按钮，我发现最好的自定义方法是使用伪元素，比如:Codepen

/*CSS is compiled from SCSS*/ .product-colors { margin-bottom: 1em; display: flex; align-items: center; } .product-colors label { position: relative; width: 2.1em; height: 2.1em; margin-right: 0.8em; cursor: pointer; } .product-colors label:before { opacity: 0; width: inherit; height: inherit; padding: 2px; border: 2px solid red; border-radius: 0.2em; content: ""; position: absolute; z-index: 1; background: transparent; top: -4px; left: -4px; } .product-colors input { position: absolute; opacity: 0; width: 0; height: 0; } .product-colors input:checked + label:before, .product-colors input:focus + label:before { opacity: 1; } <div class="product-colors"> <input type="radio" name="cs" id="cs1" value="black"> <label for="cs1" style="background:black"></label> <input type="radio" name="cs" id="cs2" value="green"> <label for="cs2" style="background:green"></label> <input type="radio" name="cs" id="cs3" value="blue"> <label for="cs3" style="background:blue"></label> <input type="radio" name="cs" id="cs4" value="yellow"> <label for="cs4" style="background:yellow"></label> </div>

你可以用盒子阴影代替这样的轮廓

    box-shadow: 0 0 1px #000000;
    border-radius: 50px;
    outline: none;

用这个吧: Box-shadow: 0px 0px 1px红色;

结合盒子阴影和轮廓。

李·海耶斯的回答有点小变化 我发现

input[type=text]:focus {
    box-shadow: 0 0 0 1pt red;
    outline-width: 1px;
    outline-color: red;
}

最后的效果非常干净。没有使用边界半径时的大小跳跃

我把轮廓设置为透明。

input[type=text] {
  outline: rgba(0, 0, 0, 0);
  border-radius: 10px;
}

input[type=text]:focus {    
  border-color: #0079ff;
}

There is the solution if you need only outline without border. It's not mine. I got if from Bootstrap css file. If you specify outline: 1px auto certain_color, you'll get thin outer line around div of certain color. In this case the specified width has no matter, even if you specify 10 px width, anyway it will be thin line. The key word in mentioned rule is "auto". If you need outline with rounded corners and certain width, you may add css rule on border with needed width and same color. It makes outline thicker.