at.svg 240 Bytes
<svg xmlns="http://www.w3.org/2000/svg" id="flag-icon-css-at" viewBox="0 0 640 480">
  <g fill-rule="evenodd">
    <path fill="#fff" d="M640 480H0V0h640z"/>
    <path fill="#ed2939" d="M640 480H0V320h640zm0-319.9H0V.1h640z"/>
  </g>
</svg>