html {
    box-sizing: border-box;
  }
  *, *:before, *:after {
    box-sizing: inherit;
  }

  body {
    margin: 0;
    padding: 0;
    font-family: basier, maison, arial, sans-serif;
    font-size: 20px;
    text-align: center;
  }

  a {
    color: blue;
  }
  
  a:visited {
    color: blue
  }

  a:hover {
    text-decoration: none;
    cursor: pointer;
  }

  code {
    color: steelblue;
    word-break: break-all;
  }

  small {
    font-size: 90%;
  }

  hr {
    margin-top: 15pt;
  }

  p {
    margin-bottom: 10pt;
  }

  li {
    margin-top: 0;
  }

  ul{
    margin-right: 0;
  }

  img {
    width: 200px;
    margin: 10px;
  }

  iframe {
    max-width: 500px;
    margin: 10px;
  }

  #top-nav {
    width: 100vw;
    height: 50px;
    position: sticky;
    top: 0;
    text-align: center;
    z-index: 15;
  }

  #title {
      text-align: center;
      background-color: white;
      display: inline-block;
      vertical-align: middle;
      width: 550px;
      margin-top: 50px;
      position: relative;
      z-index: 10;
      padding: 15px;
  }

  #title h1 {
    margin-bottom: 5px;
    font-size: 20pt;
    line-height: 25pt;
  }

  #title h2 {
    margin-top: 0;
    font-size: 13pt;
  }

  #top-nav ul {
    margin: 0;
    padding-top: 20px;
    padding-left: 0;
  }

  #top-nav li {
    display: inline-block;
    margin: 0 10px;
    border: 1px solid black;
    padding: 10px;
    margin-bottom: 10px;
  }

  #top-nav li a {
    color: blue
  }

  #top-nav li a:visited {
    color: blue
  }

  #top-nav li:hover {
      background-color: gainsboro;
/*      color: white;*/
  }

  a:hover {
    
  }

  #introduction, #codes, #ref, #alumni {
    padding: 20px;
    border: 1px solid black;
    font-size: 11pt;

  }


 .table-schedule {
   margin-top: 20px;
 }

  table, th, td {
    border: 1px solid black;
    padding: 10px;
    background-color: greenyellow;
  }

  table {
    border-collapse: collapse;
  }

  #tools {
    background-color: tomato;
    padding: 20px;
  }

.module {
    max-width: 700px;
    margin: 50px auto;
    text-align: left;
    line-height: 15pt;
    position: relative;
    z-index: 10;
}


@media all and (max-width: 600px) {
  #title {
    width: 100%;
  }

  #introduction {
    margin-top: 90px;
  }

  #schedule h2 {
    padding: 10px;
  }
}