#backdrop { position: absolute; top: 0; left: 0; width: 100vw; height: 100vh; z-index: 999; background-color: rgba(0, 0, 0, 0.262); text-align: center; } #backdrop button { top: calc(50% - (58px / 2)); right: calc(50% - (58px / 2)); display: block; position: fixed; } #myImage { max-inline-size: '100%'; block-size: 'auto'; }