.atab{
    display: flex;
}

.atab-sidebar{

  width: 400px;
  flex-shrink: 0;
  background-color: white;
} 

.atab-btn{
    display: block;
    background-color: white;
    border:1px solid #eee;
    outline: none;
    padding: 25px 0 25px 15px;
    width: 100%;
    cursor: pointer;
    text-align: left;
    color: #000;
    text-transform: uppercase;
    font-size: 16px;
}

.atab-btn:active{
    background:#fff;

}

.atab-btn-active{
    background:#486930;
    color:#fff;
}
.atab-content{
    padding:20px;
    font-size:1.5rem;
    display:none;
}

.atab-content-active{
    display:block;
}

.atab-content > :first-child{
    margin-top: 0;
}