html - 如何使按钮看起来好像具有透明边框/描边？

Question

我有一个带边框的动态宽度/高度 div。里面是一个绝对定位的按钮，位于底部的中心，与父 div 的边框重叠。我想让它看起来像边框在重叠按钮之前停止几个像素。一项要求是保持一切动态，例如，如果按钮的宽度增加或框的增加不会破坏样式。

这是我到目前为止尝试过的:

*,
*:before,
*:after {
  box-sizing: border-box;
}

html,
body {
  height: 100%;
  margin: 0;
}

body {
  background: url(https://static.pexels.com/photos/415949/pexels-photo-415949.jpeg) no-repeat top center/cover;
  font: normal 100% arial, sans-serif;
  color: #fff;
}

.box {
  max-width: 500px;
  margin: 0 auto;
  border: 6px solid #fff;
  text-align: center;
  position: relative;
  padding: 25px;
  top: 50%;
  -webkit-transform: translateY(-50%);
  transform: translateY(-50%);
}

.link {
  display: inline-block;
  background: #000;
  padding: 10px 25px;
  position: absolute;
  top: 100%;
  left: 50%;
  -webkit-transform: translate(-50%, -50%);
  transform: translate(-50%, -50%);
  color: #fff;
  text-decoration: none;
}

h1 {
  margin-top: 0;
}

.box {
  border-bottom: 0;
}

.box:before,
.box:after {
  content: '';
  position: absolute;
  left: 0;
  bottom: 1px;
  height: 6px;
  background: #fff;
  right: 75%;
}

.box:after {
  right: 0;
  left: 75%;
}

<div class="box">
  <h1>Some Header</h1>
  <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et.</p>
  <a class="link" href="#">A Link</a>
</div>

Answer 1

使用带有 before 和 after 的 flexbox 作为底部边框。这样当按钮变大时，边框会变小:

*,
*:before,
*:after {
  box-sizing: border-box;
}

html,
body {
  height: 100%;
  margin: 0;
}

body {
  background: url(https://static.pexels.com/photos/415949/pexels-photo-415949.jpeg) no-repeat top center/cover;
  font: normal 100% arial, sans-serif;
  color: #fff;
}

.box {
  max-width: 500px;
  margin: 0 auto;
  border: 6px solid #fff;
  border-bottom: none;
  text-align: center;
  position: relative;
  padding: 25px;
  top: 50%;
  -webkit-transform: translateY(-50%);
  transform: translateY(-50%);
}

.buttonWrapper {
  position: absolute;
  display: flex;
  bottom: 0;
  right: 0;
  left: 0;
  align-items: flex-end;
}

.buttonWrapper:before, .buttonWrapper:after {
  display: block;
  flex: 1;
  height: 6px;
  background: #fff;
  content: '';
}

.link {
  display: inline-block;
  background: #000;
  padding: 10px 25px;
  margin: 0 5px;
  color: #fff;
  text-decoration: none;
  transform: translateY(50%);
  align-item: middle;
}

h1 {
  margin-top: 0;
}

<div class="box">
  <h1>Some Header</h1>
  <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et.</p>
  <div class="buttonWrapper">
    <a class="link" href="#">A very long Link</a>
  </div>
</div>