bootstrap按钮底部边框宽度为百分比

Question

我有一个自举方式的自定义按钮：

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.btn
{
  background-color: #DB631E;
  border-color: #DB631E;
}
.btn-custom {
  color: #D0D4D2;
  background-color: #8F101A;
  border-color: #8F101A;
  width: 170px;
  height:120px;
  border-style: solid;
  border-bottom-color:#1252cf;
  border-bottom-width: 5px;
  font-size: 22px;
  padding: 47px 22px;  
}
.btn-custom:focus,
.btn-custom.focus {
  color: #D0D4D2;
  background-color: #8F101A;
  border-color: #8F101A;
}
.btn-custom:hover {
  color: #D0D4D2;
  background-color: #8F101A;
  border-color: #8F101A;
  width: 200px;
  height:150px;
  border-style: solid;
  border-bottom-color:#1252cf;
  border-bottom-width: 5px;
}
.btn-custom:active,
.btn-custom.active,
.open > .dropdown-toggle.btn-custom {
  color: #D0D4D2;
  background-color: #8F101A;
  border-color: #8F101A;
}
.btn-custom:active:hover,
.btn-custom.active:hover,
.open > .dropdown-toggle.btn-custom:hover,
.btn-custom:active:focus,
.btn-custom.active:focus,
.open > .dropdown-toggle.btn-custom:focus,
.btn-custom:active.focus,
.btn-custom.active.focus,
.open > .dropdown-toggle.btn-custom.focus {
  color: #D0D4D2;
  background-color: #8F101A;
  border-color: #8F101A;
}
.btn-custom:active,
.btn-custom.active,
.open > .dropdown-toggle.btn-custom {
  background-image: none;
}
.btn-custom.disabled,
.btn-custom[disabled],
fieldset[disabled] .btn-custom,
.btn-custom.disabled:hover,
.btn-custom[disabled]:hover,
fieldset[disabled] .btn-custom:hover,
.btn-custom.disabled:focus,
.btn-custom[disabled]:focus,
fieldset[disabled] .btn-custom:focus,
.btn-custom.disabled.focus,
.btn-custom[disabled].focus,
fieldset[disabled] .btn-custom.focus,
.btn-custom.disabled:active,
.btn-custom[disabled]:active,
fieldset[disabled] .btn-custom:active,
.btn-custom.disabled.active,
.btn-custom[disabled].active,
fieldset[disabled] .btn-custom.active {
  background-color: #8F101A;
  border-color: #8F101A;
}
.btn-custom .badge {
  color: #5bc0de;
  background-color: #fff;
}

＆＃13;

<button type="button" class="btn btn-custom">Default</button>

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这是我的jsfiddle。

问题：

如何使蓝色底部边框占底部边框宽度的70％并居中？
目前它与底部边界的宽度相同。

我的引导版本是

  

Bootstrap v3.3.5

Answer 1

只需从按钮上移除边框并添加伪元素（高度为5px，宽度为70％，背景颜色和位置正确）

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.btn
{
  background-color: #DB631E;
  border-color: #DB631E;
}
.btn-custom {
  color: #D0D4D2;
  background-color: #8F101A;
  border-color: #8F101A;
  width: 170px;
  height:120px;
  font-size: 22px;
  padding: 47px 22px;  
  position: relative;
}
.btn-custom:before {
  content: '';
  position: absolute;
  height: 5px;
  left: 50%;
  bottom: -5px;
  width: 70%;
  transform: translateX(-50%);
  background-color: blue;
}
.btn-custom:focus,
.btn-custom.focus {
  color: #D0D4D2;
  background-color: #8F101A;
  border-color: #8F101A;
}
.btn-custom:hover {
  color: #D0D4D2;
  background-color: #8F101A;
  border-color: #8F101A;
  width: 200px;
  height:150px;
}
.btn-custom:active,
.btn-custom.active,
.open > .dropdown-toggle.btn-custom {
  color: #D0D4D2;
  background-color: #8F101A;
  border-color: #8F101A;
}
.btn-custom:active:hover,
.btn-custom.active:hover,
.open > .dropdown-toggle.btn-custom:hover,
.btn-custom:active:focus,
.btn-custom.active:focus,
.open > .dropdown-toggle.btn-custom:focus,
.btn-custom:active.focus,
.btn-custom.active.focus,
.open > .dropdown-toggle.btn-custom.focus {
  color: #D0D4D2;
  background-color: #8F101A;
  border-color: #8F101A;
}
.btn-custom:active,
.btn-custom.active,
.open > .dropdown-toggle.btn-custom {
  background-image: none;
}
.btn-custom.disabled,
.btn-custom[disabled],
fieldset[disabled] .btn-custom,
.btn-custom.disabled:hover,
.btn-custom[disabled]:hover,
fieldset[disabled] .btn-custom:hover,
.btn-custom.disabled:focus,
.btn-custom[disabled]:focus,
fieldset[disabled] .btn-custom:focus,
.btn-custom.disabled.focus,
.btn-custom[disabled].focus,
fieldset[disabled] .btn-custom.focus,
.btn-custom.disabled:active,
.btn-custom[disabled]:active,
fieldset[disabled] .btn-custom:active,
.btn-custom.disabled.active,
.btn-custom[disabled].active,
fieldset[disabled] .btn-custom.active {
  background-color: #8F101A;
  border-color: #8F101A;
}
.btn-custom .badge {
  color: #5bc0de;
  background-color: #fff;
}

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<button type="button" class="btn btn-custom">Default</button>

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Answer 2

不要使用边框，而是使用绝对定位的伪元素：

.btn
{
  background-color: #DB631E;
  border-color: #DB631E;
}
.btn-custom {
  position: relative;
  color: #D0D4D2;
  background-color: #8F101A;
  border-color: #8F101A;
  width: 170px;
  height:120px;
  font-size: 22px;
  padding: 47px 22px;  
}
.btn-custom:after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 15%;
  right: 15%;
  height: 5px;
  background: #1252cf;
}
.btn-custom:focus,
.btn-custom.focus {
  color: #D0D4D2;
  background-color: #8F101A;
  border-color: #8F101A;
}
.btn-custom:hover {
  color: #D0D4D2;
  background-color: #8F101A;
  border-color: #8F101A;
  width: 200px;
  height:150px;
}
.btn-custom:active,
.btn-custom.active,
.open > .dropdown-toggle.btn-custom {
  color: #D0D4D2;
  background-color: #8F101A;
  border-color: #8F101A;
}
.btn-custom:active:hover,
.btn-custom.active:hover,
.open > .dropdown-toggle.btn-custom:hover,
.btn-custom:active:focus,
.btn-custom.active:focus,
.open > .dropdown-toggle.btn-custom:focus,
.btn-custom:active.focus,
.btn-custom.active.focus,
.open > .dropdown-toggle.btn-custom.focus {
  color: #D0D4D2;
  background-color: #8F101A;
  border-color: #8F101A;
}
.btn-custom:active,
.btn-custom.active,
.open > .dropdown-toggle.btn-custom {
  background-image: none;
}
.btn-custom.disabled,
.btn-custom[disabled],
fieldset[disabled] .btn-custom,
.btn-custom.disabled:hover,
.btn-custom[disabled]:hover,
fieldset[disabled] .btn-custom:hover,
.btn-custom.disabled:focus,
.btn-custom[disabled]:focus,
fieldset[disabled] .btn-custom:focus,
.btn-custom.disabled.focus,
.btn-custom[disabled].focus,
fieldset[disabled] .btn-custom.focus,
.btn-custom.disabled:active,
.btn-custom[disabled]:active,
fieldset[disabled] .btn-custom:active,
.btn-custom.disabled.active,
.btn-custom[disabled].active,
fieldset[disabled] .btn-custom.active {
  background-color: #8F101A;
  border-color: #8F101A;
}
.btn-custom .badge {
  color: #5bc0de;
  background-color: #fff;
}

<button type="button" class="btn btn-custom">Default</button>

（注意：我没有费心去改变悬停颜色;当然你必须用伪元素的背景颜色替换边框颜色。）