Full width input in a div
问题 Is it possible, without width: calc(...) nor flex (for legacy support) to have the input #what to use full width of its parent #b ? Note: Run the code snippet in full-screen and re-dimension the browser width to see the media query in action. * { padding: 0; margin: 0; } #a { float: left; background-color: red; width: 150px; } #b { background-color: blue; } #c { float: right; width: 40%; background-color: yellow; } #icon { background-color: black; width: 20px; display: inline-block; } #what {