The CSS Filter Effects specification ... It can also apply sepia, blur, and shadow effects. The feature first landed in WebKit last year and has been making its way into Web browsers.

From stunning text shadows ... Tailwind CSS v4.1 introduces robust support for CSS masking, a feature that expands your ability to create intricate and visually striking effects.

Using the CSS "drop shadow" effect you can create a drop shadow on the iframe which makes the Google map stand out on the page. Right-click the HTML file that contains your iframe. Click "Open ...