* {box-sizing: border-box;} body { margin: 0; background-color: #0d2f64; } .header { overflow: hidden; background-color: #0d2f64; color: white; text-align: center; padding: 20px 10px; } li { color: white; font-size: 22.5px; } h2 { color: white; text-align: center; } p { color: white; } a { float: left; color: white; text-align: center; padding: 12px; text-decoration: none; font-size: 18px; line-height: 25px; border-radius: 4px; } a.none { float: none; color: dodgerblue; text-align: inherit; padding: 0px; text-decoration: none; font-size: 16px; line-height: 24px; border-radius: 0px; } a.overridefloat { float: none; text-align: center; padding: 12px; text-decoration: none; font-size: 18px; line-height: 25px; border-radius: 4px; background-color: dodgerblue; color: white; } a.overridefloat:hover { background-color: #45a3ff; } a.text { font-size: 25px; font-weight: bold; text-align: center; } a:hover { color: #FFFF00; } a.active { background-color: dodgerblue; color: white; } .header-right { float: right; } @media screen and (max-width: 500px) { .header a { float: none; display: block; } .header-right { float: none; } } .column { float: left; width: 33.33%; width: calc(100% / 3); padding: 10px; height: calc(100vh - 149px) } .row:after { content: ""; display: table; clear: both; } .row { margin-left: 0px; margin-right: 0px; } @media screen and (max-width: 1200px) { .column { width: 100%; height: calc((100vh - 222px)*0.5) } }