demo.css

@font-face {
  font-family: 'ABCFavoritMono';
  font-style: normal;
  font-weight: 400;
  src: url(ABCFavoritMono-Light.woff) format('truetype');
}
@media print {
  .banner,.intro,.sidebar,footer,.tips {
    visibility: hidden;
  }
  @page {
    size: A3;
  }
  table {
    height:95%;
    font-size: 10px;
  }
}
html {
	margin:auto;
  margin-top: 5vh;
  margin-left: 1vw;
	width:80%;
}

.status {
  background-color: white;
  z-index: 99999;
  font-family: 'ABCFavoritMono';
  font-size: 0.6vw;
  color: blue;
}
.banner {
  position: fixed;
  top: 0px;
  left: 20px;
  right: 40px;
  height: 5vh;
  width: 90%;
  background-color: white;
  z-index: 99999;
}
.logo {
  font-family: 'ABCFavoritMono',monospace;
  font-size: 0.6vw;
  font-weight: bold;
  display: inline-block;
  padding: 0 0.4vw;
  color: white;
  background-color: black;
  vertical-align: center;
  height: 5vh;
}

.sidebar {
  font-family: 'ABCFavoritMono';
  font-size: 0.7vw;
  position: fixed;
  top: 10vh;
  right: 0px;
  height: 90vh;
  width: 18%;
  overflow-y: auto;
}
.sidebar>table {
  border: none;
  border-collapse: collapse;
}
.sidebar::-webkit-scrollbar {
    width: 10px;
}

.sidebar::-webkit-scrollbar-track {
    background-color: #ddd;
}

.sidebar::-webkit-scrollbar-thumb {
    box-shadow: inset 0 0 6px rgba(0, 0, 0, 0.3);
}
body{
	padding: 10px 20px;
}


.intro {
  font-family: 'ABCFavoritMono';
  font-size: 0.7vw;
}
.intro>ul {
  font-size: 0.68vw;
}
.tips {
  font-family: 'ABCFavoritMono';
  font-size: 0.7vw;
}

h1 {
	text-align: center;
	color: #222;
	margin: 0 0 30px;
}

.fileselect {
  margin: 0 0.5vw;
  display: inline-block;
  height: 5vh;
  cursor: pointer;
}
.button {
	color: white;
  cursor: pointer;
	background: linear-gradient(#000, #222);
  background-color: black;
	border: 1px solid #222;
	padding: 7px;
	transition: .3s;
	font-family: ubuntu, sans-serif;
	font-size: 1vw;
  height: 5vh;
}

.button:active {
	background: linear-gradient(#ddd, #eee);
}

.button:hover, button:focus {
	box-shadow: 0 0 2px #222;
}

#execute {
	margin-top: 5px;;
	width: 10%;
	min-width:100px;
}

.CodeMirror {
  border: 1px solid #222;
  height: auto;
}
.CodeMirror-scroll {
  overflow-y: hidden;
  overflow-x: auto;
}

.error {
	color:red;
	transition:.5s;
	overflow:hidden;
	margin: 15px;
}

.output {
	overflow: auto;
  max-height: 40vh;
  position: relative;
}

.output>table {
	width:auto;
	margin:auto;
	border:1px solid black;
 	border-collapse:collapse;
 	margin-bottom:10px;
}

.output>table>thead>tr>th {
	border:1px solid #777;
}
.output>table>tbody>tr>td {
	border:1px solid #777;
}

footer {
  font-family: 'ABCFavoritMono';
	font-size:.8em;
	color: #222;
}

.output::-webkit-scrollbar-track {
    background-color: #999;
}

.hints {
  padding-left: 2vw;
  font-family: 'ABCFavoritMono';
  font-size: 0.7vw;
  display: inline-block;
}
.hints>table {
  border: none;
  border-collapse: collapse;
}

.CodeMirror-focused {
  border: 0.5px solid lightblue;
}

/*@media (prefers-color-scheme: dark) {*/

/* Use dark mode by default, it's prettier */
.status, .banner, body, footer {
  color: #eee;
  background: #121212;
}

body a {
  color: #809fff;
}
.button, .logo {
  background-color: orange;
  color: black;
}
.button {
  background: linear-gradient(orange, orange);
  border: 1px solid orange;
}
.output::-webkit-scrollbar {
    width: 10px;
    height: 10px;
}
.output::-webkit-scrollbar-thumb {
    background-color: #333;
}
.output::-webkit-scrollbar-track {
    background-color: #222;
}
.output::-webkit-scrollbar-corner {
    background-color: #333;
}
.sidebar::-webkit-scrollbar-thumb {
    background-color: #333;
}
.sidebar::-webkit-scrollbar-track {
    background-color: #222;
}
.sidebar::-webkit-scrollbar-corner {
    background-color: #333;
}
.sidebar,.output {
  scrollbar-color: #333 #222;
}

:root {
  color-scheme: dark;
}
.CodeMirror-focused {
  border: 0.5px solid #b37400;
}