| <!DOCTYPE html> |
| <html lang="en"> |
| <head> |
| <meta charset="UTF-8"> |
| <meta name="viewport" content="width=device-width, initial-scale=1.0"> |
| <title>Document</title> |
| <style> |
| *{ |
| padding: 0; |
| margin: 0; |
| } |
| body{ |
| width: 100vw; |
| height: 100vh; |
| display: grid; |
| grid-template: 1fr/1fr; |
| } |
| .btn{ |
| width: 200px; |
| height: 50px; |
| text-align: center; |
| line-height: 50px; |
| color:green; |
| justify-self: center; |
| align-self: center; |
| } |
| .btn::after{ |
| content: ''; |
| width: 3px; |
| height: 3px; |
| display: inline-block; |
| animation-name: yd; |
| animation-duration: 1s; |
| animation-iteration-count: infinite; |
| } |
| @keyframes yd { |
| from{ |
| box-shadow: none; |
| } |
| 30%{ |
| box-shadow: 3px 0 0 currentColor; |
| } |
| 60%{ |
| box-shadow: 3px 0 0 currentColor,9px 0 0 currentColor; |
| } |
| 90%{ |
| box-shadow: 3px 0 0 currentColor,9px 0 0 currentColor,15px 0 0 currentColor; |
| } |
| to{ |
| box-shadow: 3px 0 0 currentColor,9px 0 0 currentColor,15px 0 0 currentColor; |
| } |
| } |
| </style> |
| </head> |
| <body> |
| <button class="btn">提交</button> |
| </body> |
| </html> |
