<!DOCTYPE html> <html lang="ja"> <head> <meta charset="utf-8"> <title>課題</title> <link rel="stylesheet" href="a.css"> <style type="text/css"> h1 { animation-duration: 3s; animation-name: slidein; } @keyframes slidein { from { margin-left: 100%; width: 300%; color: blue; background-color: #aaccff; } to { margin-left: 0%; width: 100%; color: black; background-color: white; } } </style> </head> <body> <h1>情報デザイン論</h1> <br> <br> <br> <h2>a</h2> </body>