<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta http-equiv="X-UA-Compatible" content="IE=edge"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <title>Document</title> <style>#a:hover ~ #b { background: #ccc }</style> </head> <body> <div id="a">Div A</div> <div>random other elements</div> <div>random other elements</div> <div>random other elements</div> <div id="b">Div B</div> </body> </html>