<div class="simpleButton">
  <a href="#">詳細はこちら</a>
</div>
                

.simpleButton a {
  color: #000;
  text-shadow: 1px 1px 1px rgba(255, 255, 255, 1);
  line-height: 1.4;
  padding: 0.6em 2.8em 0.6em 1.5em;
  display: inline-block;
  position: relative;
  border-radius: 0.2em;
  transition: all 0.3s ease;
  z-index:1;
  overflow:hidden;
}
.simpleButton a::before {
  content: "";
  width:100%;
  height:200%;
  display: block;
  background-image: linear-gradient(180deg, rgba(0, 0, 0, 0.1), rgba(0, 0, 0, 0.3));
  border-radius: 0.3em;
  position:absolute;
  top:0;
  left:0;
  z-index:-1;
  transition: all 0.3s ease;
}
.simpleButton a::after {
  content: "";
  width: 0.8em;
  height: 0.8em;
  display: block;
  background: url("/img/icon/arrow-circle-o-right.svg") no-repeat center center;
  background-size: 100% auto;
  filter: drop-shadow(1px 1px 1px rgba(255, 255, 255, 1)); 
  position: absolute;
  top: 50%;
  right: 1.4em;
  margin-top:-0.4em;
  transition: all 0.3s ease;
}
.simpleButton a:hover {
  color: #000;
}
.simpleButton a:hover::before{
  top:-50%;
}
.simpleButton a:hover::after{
  right: 1em;
}
              

.simpleButton a {
  color: #000;
  text-shadow: 1px 1px 1px rgba(#FFF, 1);
  line-height: 1.4;
  padding: 0.6em 2.8em 0.6em 1.5em;
  display: inline-block;
  position: relative;
  border-radius: 0.2em;
  transition: all 0.3s ease;
  z-index:1;
  overflow:hidden;
  &::before{
    content: "";
    width:100%;
    height:200%;
    display: block;
    background-image: linear-gradient(180deg, rgba(#000, 0.1), rgba(#000, 0.3));
    border-radius: 0.3em;
    position:absolute;
    top:0;
    left:0;
    z-index:-1;
    transition: all 0.3s ease;
  }
  &::after{
    content: "";
    width: 0.8em;
    height: 0.8em;
    display: block;
    background: url("/img/icon/arrow-circle-o-right.svg") no-repeat center center;
    background-size: 100% auto;
    filter: drop-shadow(1px 1px 1px rgba(#FFF, 1)); 
    position: absolute;
    top: 50%;
    right: 1.4em;
    margin-top:-0.4em;
    transition: all 0.3s ease;
  }
  &:hover{
    color: #000;
    &::before{
      top:-50%;
    }
    &::after{
      right: 1em;
    }
  }
}