.accordion{
    position: relative;
}
.menu {
    cursor: pointer;
    transition: opacity .3s;
}
.menu:hover{
      opacity: 0.7;
}
  /* .contents {
    display: none;
    border: 1px solid black;
    padding: 10px;
    line-height: normal;
    height: auto;
    opacity: 1;
    text-align: center;
  } */
  
.contents {
    text-align: center;
    height: 0;
    overflow: hidden;
    opacity: 0;
    position: absolute;
    transition-duration: 0.5s;
    width: 100%;
    z-index: 100;
}
  
.accordion.is-active .contents {
    background: #007749;
    line-height: normal;
    height: auto;
    opacity: 1;
}
.contents ul li + li{
    border-top: 1px solid #ffffff;
}
.contents ul li a{
    color: #ffffff;
    display: block;
    opacity: 0;
    padding: 20px;
}
.accordion.is-active .contents ul li a{
    opacity: 1;
}