CSS Box Sizing animation effect

CSS Box Sizing animation

This animation alternates the box-sizing model between border-box and content-box. The fixed width and height make it easy to compare how borders and padding contribute to the rendered size.

<style> .box-sizing { /* Uncomment as needed. */ /* width: 100px; */ /* height: 100px; */ /* background-color: deeppink; */ } .box-sizing::after { content: 'A'; position: absolute; z-index:20; color: black; font-size:24px; font-weight:bold; animation-name: box-sizing; animation-duration: 5s; animation-iteration-count: infinite; animation-timing-function: linear; /* For box-sizing to take effect we need to specify a width and height*/ width:42px; height:37px; border:3px solid black; outline:2px solid deeppink; padding:5px; /*display:flex; align-items:center; justify-content:center;* text-shadow:1px 0 3px aqua;*/ } @keyframes box-sizing { 0% { box-sizing: border-box; } 20% { box-sizing: content-box;} 40% { box-sizing: border-box;} 60% { box-sizing: content-box; } 80% { box-sizing: border-box; } 100% { box-sizing: content-box; } } </style>
Animation effects source code licensed under the MIT License

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