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<html><head><style>input:invalid { border: 2px solid red;}</style></head><body><h1>Demo of the :invalid selector</h1><input type="email" value="supportEmail"><p>Try typing a legal e-mail address, to see the styling disappear.</p></body><!-- Mirrored from www.w3schools.com/cssref/tryit.php?filename=trycss_sel_invalid by HTTrack Website Copier/3.x [XR&CO'2014], Wed, 21 Dec 2022 17:38:45 GMT --></html>