style.css

body {
    font-family: Arial, Helvetica, sans-serif;
    margin: 0px;
    height: 100vh;
}


* {
  box-sizing: border-box;
}

.column_l {
  float: left;
  width: 70%;
  padding: 10px;
  height: 100%;
}

.column_r {
  float: right;
  width: 30%;
  padding: 10px;
  background-color: #eee;
  height: 100%;
  border-left: 1px solid #ddd;
}

/* Clear floats after the columns */
.row {
  flex:1;
  height: calc(100% - 50px);;
}

.CodeMirror {
  border: 1px solid #eee;
  height: auto;
  font-size: 12pt;
}

.work-area {
    margin: 20px;
}

.check-button {
    margin-left: 20px;
}

.result {
  background-color: #fff;
  border: 1px solid #ccc;
  padding: 10px;
  font-family: "Lucida Console", "Courier New", monospace;
  overflow:auto;
}

button {
  border: none;
  padding: 10px;
  text-align: center;
  text-decoration: none;
  display: inline-block;
  font-size: 16px;
  margin: 4px 2px;
  cursor: pointer;
}

button:hover {
  background-color: #ddd;
}

.button4 {
  background-color: rgba(51, 51, 51, 0.05);
  border-radius: 8px;
  border-width: 0;
  color: #333333;
  cursor: pointer;
  display: inline-block;
  font-size: 14px;
  font-weight: 500;
  line-height: 20px;
  list-style: none;
  padding: 10px 12px;
  text-align: center;
  transition: all 200ms;
  vertical-align: baseline;
  white-space: nowrap;
  user-select: none;
  -webkit-user-select: none;
  touch-action: manipulation;
}

select {
  padding: 10px;
}

.code-wrapper {
    margin: 20px;
    padding: 0px;
    border: 2px solid black;
}

/* Add a black background color to the top navigation */
.topnav {
  background-color: #333;
  overflow: hidden;
    height:50px;
}

/* Style the links inside the navigation bar */
.topnav a {
  float: left;
  color: #f2f2f2;
  text-align: center;
  padding: 14px 16px;
  text-decoration: none;
  font-size: 17px;
  height:50px;
}

/* Change the color of links on hover */
.topnav a:hover {
  background-color: #ddd;
  color: black;
}

/* Add a color to the active/current link */
.topnav a.active {
  background-color: #046DAA;
  color: white;
}