:root {
    color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
    html {
        color: #cccccc;
        background: #333333;
    }

    a {
        color: yellow;
    }

    a:visited {
        color: orange;
    }
}


/* all */
@media screen {
  body {
    font-family: 'Open Sans', sans-serif;
    font-size: 14px;
    font-weight: normal;
  }
  
  #main {
    margin-left: auto;
    margin-right: auto;
    text-align: center;
  }

  #test {
    margin-left: auto;
    margin-right: auto;
  }
  
  canvas {
    border: 0px;
    margin-top: 10px;
    margin-bottom: 10px;
    -webkit-tap-highlight-color: rgba(0,0,0,0);
  }
  
  #error_message_desktop {
      color: red;
      font-size: 150%;
      font-weight: bold;
      height: 30px;
  }

  #error_message_mobile {
      color: red;
      font-weight: bold;
      font-size: 100%;
      height: 20px;
  }
  
  p {
      margin-top: 20px;
      margin-bottom: 10px;
  }
  
  #clear_button {
      float: left;
      width: 30%;
  }
  
  #solve_button {
      float: right;
      width: 30%;
  }
  
  #buttons {
      position: relative;
  }

  #modal {
      display: none;
      position: fixed;
      z-index: 1;
      left: 0;
      top: 0;
      width: 100%;
      height: 100%;
      overflow: auto;
      background-color: rgba(0, 0, 0, 0.4);
  }

  #modal_keyboard {
    width: 315px;
    margin-left: auto;
    margin-right: auto;
    text-align: center;
    margin-top: 150px;
    background-color: #333333;
    padding-top: 20px;
    padding-bottom: 20px;
  }

  #modal_keyboard table {
    width: 100%;
    margin-left: auto;
    margin-right: auto;
  }

  #numeric_buttons td {
    width: 33%;
    padding-bottom: 20px;
    text-align: center;
  }

  #function_buttons td {
    width: 50%;
  }

  #modal #numeric_buttons button {
      padding: 10px 30px 10px 30px;
  }

  #modal #function_buttons button {
      padding: 10px 30px 10px 30px;
  }
  
  .left {
      text-align: left;
      padding-left: 15px;
  }

  .right {
      text-align: right;
      padding-right: 15px;
  }
}

/* phone */
@media screen and (min-width: 0px) and (max-width: 449px) {
  #main {
    width: 315px;
  }

  #test {
    width: 315px;
  }

  canvas {
    width: 315px;
    height: 315px;
    -webkit-tap-highlight-color: rgba(0,0,0,0);
  }
}

/* tablet and larger */
@media screen and (min-width: 450px) {
  #main {
    width: 450px;
  }

  #test {
    width: 450px;
  }

  canvas {
    width: 450px;
    height: 450px;
    -webkit-tap-highlight-color: rgba(0,0,0,0);
  }
}