chromium/chrome/browser/resources/nearby_internals/log_object.html

<style>
  :host {
    padding: 3px;
  }

  :host(.warning-log) {
    background-color: rgb(255, 252, 239);
  }

  :host(.error-log) {
    background-color: rgb(255, 241, 241);
  }

  :host(.verbose-log) {
    background-color: rgb(235, 235, 235);
  }

  :host(.default-log) {
    background-color: rgb(255, 255, 255);
  }

  #log-container {
    color: #888;
    display: flex;
    font-size: 10px;
    padding: 6px;
  }

  #flex {
    flex: 1;
  }

  #text {
    display: inline-block;
    text-align: start;
    width: 100%;
  }
</style>
<div>
  <p id="text">[[logMessage.text]]</p>
  <div id="log-container">
    <span>[[logMessage.time]]</span>
    <div id="flex"></div>
    <span>[[getFilenameWithLine_(logMessage.file, logMessage.line)]]</span>
  </div>
</div>