.Editor { display: flex; flex-direction: row; height: 100%; width: 100%; } .Editor-textwrapper { flex: 1; flex-basis: 0; position: relative; background: white; font-family: ui-monospace, "Cascadia Code", "Source Code Pro", Menlo, Consolas, "DejaVu Sans Mono", monospace; font-weight: normal; font-size: 3rem; text-align: initial; } .Editor-textarea, .Editor-underlay { font-family: inherit; font-weight: inherit; font-size: inherit; padding: 5px; } .Editor-textarea { position: absolute; top: 0; bottom: 0; left: 0; right: 0; width: 100%; height: 100%; box-sizing: border-box; border: none; background-color: transparent; } .Editor-ast { flex: 1; background: green; } .Editor-underlay { width: 100%; height: 100%; pointer-events: none; color: transparent; }