outline-offset

outline-offset CSS 属性用于设置 outline 与一个元素边缘或边框之间的间隙。

outline是元素的轮廓，悬浮在元素边框之上。元素和其轮廓之间是透明的。也就是说，它们之间的颜色会继承父元素的背景色。

The space will be transparent (the parent will determine the background).

/* <length> values */
outline-offset: 3px;
outline-offset: 0.2em;

/* Global values */
outline-offset: inherit;
outline-offset: initial;
outline-offset: unset;

<length>

元素和轮廓间的宽度. 详见 <length> . 负值将轮廓绘制在元素之内.

<length>

p {
  outline: dashed thin;
  /* Move the outline 10px away from the border */
  outline-offset: 10px;
  border:1px solid black;
}

Html

<p>outline: offset 10px. Border is solid and outline is dashed</p>

上面的代码将产生以下效果:

另一个例子:

outline: multiple offsets;