webui/src/sketch-app-shell.css

html,
body {
  height: 100%;
}

body {
  margin: 0;
  display: flex;
}

/* 
 * Import Monaco editor's Codicon font - this is critical for icons
 * IMPORTANT: This font-face declaration MUST remain in global CSS.
 * Chrome does not apply @font-face rules properly when they're inside shadow DOM.
 * Do not move this to the sketch-monaco-view component despite it being used there.
 */
@font-face {
  font-family: "codicon";
  font-display: block;
  src: url("./monaco/min/vs/base/browser/ui/codicons/codicon/codicon.ttf")
    format("truetype");
}