<!DOCTYPE html> <html> <head> <meta charset="utf-8" /> <title></title> <link rel="stylesheet" type="text/css" href="1.css"/> </head> <body> <div class="header"> logo </div> <div class="nav"> nav </div> <div id="content"> <div class="banner_1"> <div class="left_up_1"> left_up_1 </div> <div class="left_up_2"> left_up_2 </div> <div class="left_down_1"> left_down_1 </div> <div class="left_down_2"> left_down_2 </div> </div> <div class="banner_2"> <div class="center_up"> center_up </div> <div class="center_down"> center_down </div> </div> <div class="banner_3"> <div class="right_up"> right_up </div> <div class="right_down"> right_down </div> </div> </div> <div class="footer"> footer </div> </body> </html> css .header{ height: 50px; background: yellow; } .nav{ height: 20px; background-color: aquamarine; } .div{ height: 17.5rem; width: 100%; } #content{height: 280px; } .banner_1{ width: 35%; height: 17.5rem; float: left; margin: 0; } .banner_2{ width: 30%; height: 280px; float: left; margin: 0; } .banner_3{ width: 35%; height: 17.5rem; float: right; margin: 0; } .left_up_1{ width: ; height: 70px; background: gray; } .left_up_2{ width: ; height: 70px; background: blueviolet; } .left_down_1{ width: ; height: 70px; background: salmon; } .left_down_2{ width: ; height: 70px; background: darksalmon; } .center_up{ width: ; height: 100px; background: seagreen; } .center_down{ width: ; height: 180px; background: chartreuse; } .right_up{ background: cornflowerblue; width: ; height: 5rem; } .right_down{ background: palevioletred; width: ; height:12.5rem; } .footer{ background: aquamarine; height: 1.875rem; }