style.css

@import url("https://fonts.googleapis.com/css2?family=Source+Sans+3:wght@300;400;500;600;700&display=swap");

body {
  margin: 0;
}

a {
  color: white;
  text-decoration: none;
}

.container {
  font-family: "Source Sans 3", sans-serif;
}

.header {
  background: #000;
  color: #fff;
  padding: 1rem 0.5rem;
  border-bottom: 5px solid #333;
}

.header .title {
  padding: 0.5rem;
}

.header .title .main-title {
  font-size: 22px;
  font-weight: 600;
  margin-bottom: 0.2rem;
}

.header .title .sub-title {
  font-size: 15px;
}

.header .title .sub-title span {
  color: #999;
}

.editor {
  width: 33.33%;
  height: 100%;
  float: left;
  box-sizing: border-box;
  position: relative;
}

.editor #html {
  border-right: 1px solid #777;
}

.editor #css {
  border-left: 20px solid #333;
  border-right: 1px solid #777;
}

.editor #js {
  border-left: 20px solid #333;
}

.editor-title {
  padding: 0.5rem;
  font-size: 1.2rem;
  padding-left: 2rem;
  transition: 150ms;
}

.editor-title-html:hover {
  color: #dd4b25;
  font-weight: bold;
  cursor: default;
}

.editor-title-css:hover {
  color: #254bdd;
  font-weight: bold;
  cursor: default;
}

.editor-title-js:hover {
  color: #f0dc55;
  font-weight: bold;
  cursor: default;
}

.code-box {
  position: relative;
  height: calc(50vh - 4.6rem);
  border-top: 1px solid #000;
  border-bottom: 10px solid #333;
  overflow: hidden;
}

.preview {
  position: relative;
  height: calc(90vh - 30px);
  background: #fff;
  border-top: 15px ridge #333;
}

.preview iframe {
  width: 100%;
  height: 100%;
}

::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

::-webkit-scrollbar-track {
  background: transparent;
}

::-webkit-scrollbar-thumb {
  background: #555;
  border-radius: 20px;
}

::-webkit-scrollbar-thumb:hover {
  background: #666;
  border-radius: 20px;
}