<button class="button-close"></button>

//Settings
$line-height: 8px;
$line-height-hover: 15px;
$line-color: #a1905d;
$line-transition: all .2s cubic-bezier(.25,.46,.45,.94);

.button-close{
  display: block;
  position: relative;
  width: 48px;
  height: 48px;
  background: #fff;
  color: $line-color;
  border: 1px solid #a1905d;
  margin: 100px auto;
  outline: none;
  
  &:hover{
    &:before{
      width: $line-height-hover;
    }
    
    &:after{
      width: $line-height-hover;
    }
  }
  
  &:before{
    content: '';
    position: absolute;
    left: 50%;
    top: 50%;
    width: 0;
    height: 1px;
    border-left: $line-height solid currentColor;
    border-right: $line-height solid currentColor;
    -webkit-transform: translate3d(-50%,-50%,0) rotate(-45deg);
    transition: $line-transition;
  }
  
  &:after{
    content: '';
    position: absolute;
    left: 50%;
    top: 50%;
    width: 0;
    height: 1px;
    border-left: $line-height solid currentColor;
    border-right: $line-height solid currentColor;
    -webkit-transform: translate3d(-50%,-50%,0) rotate(45deg);
    transition: $line-transition;
  }
}