body, html {
    margin: 0;
    height: 100%;
}
#main {
    display: flex;
    height: calc(100vh - 56px);
}
#editor, #preview {
    flex: 1;
    height: 100%;
    padding: 1rem;
    font-family: monospace;
    overflow-y: auto;
}
#editor {
    background: #1e1e1e;
    color: #f8f8f2;
    border-right: 1px solid #ccc;
}
#preview {
    background: #f1f1f1;
    white-space: pre-wrap;
    word-wrap: break-word;
}
.error {
    color: red;
    font-weight: bold;
}