 
.btn {
    position: relative;
    display: inline-block;
    font-weight: $btn-font-weight;
    line-height: $btn-line-height;
    color: $body-color;
    white-space: nowrap;
    text-align: center;
    vertical-align: middle;
    background-image: none;
    border: $btn-border-width solid transparent;
    @include button-size($btn-padding-y, $btn-padding-x, $btn-font-size, $border-radius);
    //padding: $btn-padding-y $btn-padding-x;
    //font-size: $btn-font-size;
    //border-radius: $border-radius;
    box-shadow: $btn-box-shadow;
    cursor: pointer;
    &.disabled,
    &[disabled] {
      cursor: not-allowed;
      opacity: $btn-disabled-opacity;
      box-shadow: none;
      > * {
        pointer-events: none; // 不接受鼠标事件，鼠标显示红色的圈
      }
    }
  }
   
  .btn-lg {
    @include button-size($btn-padding-y-lg, $btn-padding-x-lg, $btn-font-size-lg, $border-radius-lg);
  }
   
  .btn-lg {
    @include button-size($btn-padding-y-sm, $btn-padding-x-sm, $btn-font-size-sm, $border-radius-sm);
  }
   
  .btn-primary {
    @include button-style($primary, $primary, $white)
  }
   
  .btn-danger {
    @include button-style($danger, $danger, $white)
  }
   
  .btn-default {
    @include button-style($white, $gray-400, $body-color, $white, $primary, $primary)
  }
   
  .btn-link {
    font-weight: $font-weight-normal;
    color: $btn-link-color;
    text-decoration: $link-decoration;
    box-shadow: none;
    &:hover{
      text-decoration: $btn-link-hover-color;
      text-decoration: $link-hover-decoration;
    }
    &:focus,
    &.focus {
      text-decoration: $link-hover-decoration;
      box-shadow: none;
    }
    &:disabled,
    &.disabled {
      color: $btn-link-hover-color;
      pointer-events: none;
    }
  }