_menu.scss

#menu__toggle {
    opacity: 0;
    display: none;
  }
  
  #menu__toggle:checked ~ .menu__btn > span {
    transform: rotate(45deg);
  }
  #menu__toggle:checked ~ .menu__btn > span::before {
    top: 0;
    transform: rotate(0);
  }
  #menu__toggle:checked ~ .menu__btn > span::after {
    top: 0;
    transform: rotate(90deg);
  }
  #menu__toggle:checked ~ .menu__box {
    visibility: visible;
    left: 0;  
    display: block;  
    height: calc(100vh - 60px);
    
  } 

  
  
  .menu__btn {
    display: flex;
    align-items: center;
    position: fixed;
    top: 20px;
    left: 20px;
  
    width: 26px;
    height: 26px;
  
    cursor: pointer;
    z-index: 1;
  }
  
  .menu__btn > span,
  .menu__btn > span::before,
  .menu__btn > span::after {
    display: block;
    position: absolute;
  
    width: 100%;
    height: 2px;
  
    background-color: #616161;
  
    transition-duration: .25s;
  }
  .menu__btn > span::before {
    content: '';
    top: -8px;
  }
  .menu__btn > span::after {
    content: '';
    top: 8px;
  }
  
  .menu__box {
    display: none; 
    visibility: hidden;
    top: 0;
    left: -100%; 
    height: 100%; 
    margin: 0;
    padding: 80px 0; 
    list-style: none; 
    background-color:  $grey; 
    border-right: 1px solid #d7d7d7;  
    transition-duration: .25s;
  }
  
  .menu__item {
    display: block;
    padding: 7px 48px;
    color: #333;
    font-size: 17px;
    text-decoration: none; 
    transition-duration: .25s;
  }
  .menu__box .active{
    color: $green_text;
    background-color: $grey;
  }
  .menu__item:hover {
    background-color: #CFD8DC;
  }