<!DOCTYPE html><html><head><style>button {background-color: red;opacity: 0.5;}</style></head><body><h1>The opacity Property</h1><p>The following div element's opacity is 0.5. Note that both the text and the background-color are affected by the opacity level:</p><button>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Etiam semper diam at erat pulvinar, at pulvinar felis blandit...</button></body></html>