If your browser supports display: grid and shape-outside: circle(), the content will be darkgreen with a dashed border.
.box { border: 4px solid blue; color: blue; } @supports (display: grid) and (shape-outside: circle()) { .box { border: 4px dashed darkgreen; color: darkgreen; } }
<div class="box"> If your browser supports display: grid and shape-outside: circle(), the content will be darkgreen with a dashed border. </div>