styles.css

body {
    margin: 0;
    padding-top: 35%;
    position: relative;
   }
   
   #main {
           
       padding: 20px;
       box-shadow: 0 0 100px 80px  sky;
       background: sky;
       text-align: center;
       
   }
   
   .dif {
       display: inline-block ;
       margin-top: 8px;
       font-weight: bold;
       font-size: 1em;
       width: 120px;
   }
   
   
   #log {
      display:none;
      position: relative;
      font-weight: bolder;
      font-size: 0.8em;
      text-align: center;
   }
   
   canvas {
       position: fixed;
       display: block; 
       border: 3px solid #eee;
       margin: auto;
       border-radius: 7px;
       box-shadow: 0 0 15px;
   }
   
   #info {
       margin-left: 40px;
       color: red;
   }
   button {
      border:1px solid white;
      border-radius: 50px;
      box-shadow: 22px 22px 43px #489dcf, 
      -22px -22px 43px #62d5ff;
      padding: 10px 40px;
      font-weight: bold;
      background:  #55b9f3;
      
   }
   
   #btn-left, #btn-right {
       border-radius: 50%;
       padding: 0 20px ;
       font-size: 2em;
   }
   
   #infdiv {
       display:none;
       position: relative;
       margin-auto
       width: 80%;
       border: 3px solid lightblue;
       background-color: white;
       padding: 10px;
       text-align: center;
       border-radius: 10px;
       box-shadow: 0 0 20px;
       font-weight: bolder;
       font-size: 0.9em;
   }
   
   .modal {
     border-radius: 10px;
     display: none; 
     position: relative;
     z-index: 99; 
     overflow: auto;
     background-color: rgba(0,100,0,0.5); 
   }
   
   
   .modal-content {
     color: white;
     background-color: rgba(0,100,0,0.4); 
     margin: 15% auto; 
     padding: 20px;
     border: 2px solid white;
     border-radius: 10px;
     width: 80%;
     text-align: center;
   }
   
   
   .close {
     color: #aaa;
     float: right;
     font-size: 28px;
     font-weight: bold;
   }
   
   .close:hover,
   .close:focus {
     color: black;
     text-decoration: none;
     cursor: pointer;
   }