main
css
html, body, header, main, nav, footer { box-sizing: border-box; margin: 0; padding: 0; } html{ width: 100%; height: 100%; background-color: lightgray; } body { width: 940px; height: 100%; margin: 0 auto; background: antiquewhite; } header{ width: 100%; height: 100px; padding: 1rem; text-align: center; background: orange; color: green; } header h1{ margin: 0; padding-top: 0.5rem; } main{ padding: 1rem; float: right; width: 80%; height: calc(100% - 100px - 2rem); overflow: auto; } nav{ float: left; width: 20%; height: calc(100% - 100px - 2rem); overflow: auto; border-right: solid 1px gray; padding: 1rem; } footer{ clear: both; width: 100%; height: 2rem; padding-top: 0.5rem; text-align: center; color: white; background: green; }