.container { 
    height: 90px;
    position: relative;
    border: 3px solid rgb(0, 255, 255); 
  }
  
  .center {
    margin: 0;
    position: absolute;
    top: 50%;
    left: 50%;
    -ms-transform: translate(-50%, -50%);
    transform: translate(-50%, -50%);
  }  
   .section {
        height: 300px;
        background-color: #b19797;
        color: white;
        display: flex;
  }

   #footer {
        position: fixed;
        bottom: 0;
        width: 100%;
        height: 50px;
        background: #373d37;
        color: white;
  }
   aside {
    padding-left: 5px;
    padding-right: 5px;
    padding-top: 5px;
    padding-bottom: 5px;
    margin-left: 5px;

    background-color: red;
  }
  .asideleft {
    float: left;
  }
  .asideright {
    float: right;
  }
   ul {
    position: relative;
    
    width: 100%;
    list-style-type: none;
    margin: 0;
    padding: 0;
    background-color: rgb(255, 252, 69);
   }
   li {
    font-family: Comic Sans MS, cursive;
    font-size: 20px;
    display: inline;
    float: right;
   }
   a {
    display: block;
    padding: 20px;
    
  }
  li a:hover {
    background-color: fuchsia;
  }
  .header {
    text-align: left;
    padding: 20px;
  }
  #grad1 {
    background-image: linear-gradient(rgb(255, 114, 201), rgb(255, 206, 114));
  }
  #grad2 {
    background-image: linear-gradient(rgb(255, 118, 232), rgb(0, 255, 234));
  }

  body {
    min-height: 100%;
  }
  footer {
    margin-top: auto;
  }

  .div { 
    transition: transform 2s;
  }


  .header2 {
    background-color: antiquewhite;
    text-align: center;
    padding: 20px;
  }

  .topnav {
    overflow: hidden;
    background-color: antiquewhite;
  }

  .topnav a {
    float: left;
    display: block;
    color: black;
    text-align: center;
    padding: 14px 16px;
    text-decoration: double;
  }

  .topnav a:hover {
    background-color: blueviolet;
    color: antiquewhite ;
  }

  
  .div:hover {
    transform: rotate(360deg);
    background: 
     linear-gradient(rgba(255,0,0,1) 0%, rgba(255,154,0,1) 10%, rgba(208,222,33,1) 20%, rgba(79,220,74,1) 30%, rgba(63,218,216,1) 40%, rgba(47,201,226,1) 50%, rgba(28,127,238,1) 60%, rgba(95,21,242,1) 70%, rgba(186,12,248,1) 80%, rgba(251,7,217,1) 90%, rgba(255,0,0,1) 100%) 
     0 0/100% 200%;
     animation: a 1s linear infinite;
  }

  @keyframes a {
    to {background-position:0 -200%}
  }