* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: sans-serif;
  display: flex;
  flex-direction: column;
  height: 100vh;
}

header {
  background-color: #20232a;
  color: white;
  padding: 1rem;
  text-align: center;
}

.container {
  display: flex;
  flex: 1;
}

#editor,
#preview {
  flex: 1;
  padding: 1.5rem;
  font-size: 1rem;
  line-height: 1.6;
  overflow-y: auto;
}

#editor {
  border: none;
  border-right: 1px solid #ccc;
  background-color: #f4f4f4;
  resize: none;
  outline: none;
}

#preview {
  background-color: #ffffff;
}

#preview h1,
#preview h2 {
  border-bottom: 1px solid #eaecef;
  padding-bottom: 0.3em;
  margin-bottom: 16px;
}
#preview code {
  background-color: #f6f8fa;
  padding: 0.2em 0.4em;
  border-radius: 3px;
}
#preview pre code {
  display: block;
  padding: 1em;
  overflow-x: auto;
}