Google developer tools HTML-based native context menu.

devtoolscontext.html

<style>
  .soft-context-menu-glass-pane {
    position: absolute;
    top: 0;
    bottom: 0;
    left: 0;
    right: 0;
    z-index: 20000;
  }
  
  .soft-context-menu {
      position: absolute;
      border: 1px solid rgba(196, 196, 196, 0.9);
      border-top: 1px solid rgba(196, 196, 196, 0.5);
      border-bottom: 1px solid rgba(150, 150, 150, 0.9);
      padding: 4px 0 4px 0;
      border-radius: 4px;
      background-color: white;
      -webkit-box-shadow: 0 5px 10px rgba(0, 0, 0, 0.25);
  }
  
  .soft-context-menu-item {
      width: 100%;
      line-height: 13px;
      font-size: 14px;
      border-top: 1px solid transparent;
      border-bottom: 1px solid transparent;
      padding: 2px 7px 2px 6px;
      margin: 0 13px 0 0;
      white-space: nowrap;
  }
  
  .soft-context-menu-separator {
      height: 10px;
      margin: 0 1px;
  }
  
  .soft-context-menu-separator > .separator-line {
      margin: 0;
      height: 5px;
      border-bottom: 1px solid rgb(227, 227, 227);
      pointer-events: none;
  }
  
  .soft-context-menu-item-mouse-over {
      border-top: 1px solid rgb(56, 121, 217);
      border-bottom: 1px solid rgb(56, 121, 217);
      background-color: rgb(56, 121, 217);
      color: white;
  }
  
  body.platform-mac .soft-context-menu-item-mouse-over {
      border-top: 1px solid rgb(90, 131, 236);
      border-bottom: 1px solid rgb(18, 88, 233);
      background-image: -webkit-gradient(linear, left top, left bottom, from(rgb(100, 140, 243)), to(rgb(36, 101, 243)));
  }
  
  .soft-context-menu-item-checkmark {
      color: rgb(108, 108, 108);
      pointer-events: none;
  }
  
  .soft-context-menu-item-submenu-arrow {
      color: black;
      float: right;
      pointer-events: none;
  }
  
  .soft-context-menu-item-mouse-over .soft-context-menu-item-checkmark {
      color: white;
  }
  
</style>

<div class="soft-context-menu-glass-pane" tabindex="0">
	<div class="soft-context-menu" tabindex="0" style="top: 639px; left: 163px;">
		<div class="soft-context-menu-item">
			<span class="soft-context-menu-item-checkmark" style="opacity: 0;">✓</span> Edit as HTML
		</div>
		<div class="soft-context-menu-item">
			<span class="soft-context-menu-item-checkmark" style="opacity: 0;">✓</span> Copy as HTML
		</div>
		<div class="soft-context-menu-item">
			<span class="soft-context-menu-item-checkmark" style="opacity: 0;">✓</span> Copy XPath
		</div>
		<div class="soft-context-menu-item">
			<span class="soft-context-menu-item-checkmark" style="opacity: 0;">✓</span> Delete Node
		</div>
		<div class="soft-context-menu-separator">
			<div class="separator-line"></div>
		</div>
		<div class="soft-context-menu-item">
			<span class="soft-context-menu-item-checkmark">✓</span> Word Wrap
		</div>
	</div>
</div>