The CSS from [WayBack/Archive.is] Naughty naughty no alt that shows the below red moving rendering of images that do not have an alt-text is simple:

  <style>     body {       margin: 5vw;     }      img {       max-width: 25vw;       margin: 1vw;       box-sizing: border-box;     }     img:not([alt]) {       border: 2px solid red;       animation: pulse 1.2s ease infinite;     }      @keyframes pulse {       0% {         transform: scale(1) rotate(0);       }       25% {         transform: scale(1.3) rotate(15deg);         filter: blur(2px);         opacity: 0.8;         box-shadow: 0 0 2vw 2vw red;       }       50% {         transform: scale(1) rotate(0);         filter: none;       }       75% {         transform: scale(1.3) rotate(-15deg);         filter: blur(5px);         opacity: 0.8;         box-shadow: 0 0 2vw 2vw red;       }       100% {         transform: scale(1) rotate(0);       }     }   </style>

Less intrusive CSS fragements are

img:not([alt]) {   filter: blur(5px); }

and

img:not([alt]) {   border: 5px solid red; }

Via:

--jeroen

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