Complete Code For Increasing Border Size Using CSS Animation.
<!DOCTYPE html> <html> <head> <title>How Can I Increase Border Size Using CSS Animation</title> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.6/css/bootstrap.min.css"/> <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css"> </head> <style> * { box-sizing: border-box; } body { background-color: #777891; } #myDIV { width: 300px; height: 200px; border: 1px solid #0077b3; animation: mymove 5s infinite; } @keyframes mymove { 25% {border: 15px solid #0088cc;} 50% {border: 20px solid #0099e6;} 75% {border: 25px solid #00aaff;} 100% {border: 30px solid #66ccff;} } </style> <body> <br/><br/> <div class="container"> <br> <div class="text-center"> <h1 id="color" style="color: white;">Increase Border Size Using CSS Animation</h1> </div> <div class="well"> <div id="myDIV"></div> </div> </div> </body> </html>