.volver, .a, .empezar {
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 10vw;
    font-weight: 700;
    color: white;
    text-transform: uppercase;
  }
  
    
  header {
    position: fixed;
    right: 0;
  }
  
  .nav li {
    list-style-type: none;
    padding: 1em 0;
  }
  
  
  .nav {
    font-family: 'Roboto Light';
    background-color: #242424;
    position: fixed;
    top: 0;
    height: 100%;
    width: 50%;
    max-width: 400px;
    color: white;
    text-align: left;
    box-shadow: -3px 0 10px rgba(0, 0, 0, 0.2);
    padding-top: 20px;
    display: block;
    z-index: 99;
  }
  
  .nav-close-menu:focus {
      outline: none;
  }
  
  .nav ul {
      padding: 0;
      margin: 0;
      padding-left: 20px;
  }
  
  .nav:not(:target) {
    right: -100%;
    transition: right 1.5s;
  }
  
  .nav:target {
    right: 0;
    transition: right 1s;
  }
  
  #close-nav:not(:target) {
    right: -100%;
    transition: right 1.5s;
  }
  
  #close-nav:target {
    right: 0;
    transition: all 1s;
  }
  
  #close-nav:not(:target) {
    right: 0;
    transform: rotate(360deg);
  }
  
  .nav a {
    border-bottom: 2px solid transparent;
    transition: all .2s ease-in-out;
  }
  
  .nav-close-menu{
    width: 100%;
    text-align: center;
    display: block;
  }

  .nav-close-menu img{
      width: 20px;
      text-align: center;
  }