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                <div id="glassContainer" class="glass">
  <p>Una técnica CSS muy "cool" y "trendy" que podréis dominar con el tutorial de <a href="" title=""></a></p>
  <button id="switchMode" type="submit">Modo nocturno</button>
  <img src="">


* {
  box-sizing: border-box;
body {
  margin: 0;
  font: 18px/1.5 roboto, arial, helvetica, sans-serif;
  color: #223355;
  background: transparent url( no-repeat center center fixed;
  background-size: cover;
h1 {
  margin: 12px;
  color: #113355;
p {
  margin: 12px;
a {
  text-decoration: none;
img {
  position: absolute;
  right: -12%;
  width: 38%;
  filter:drop-shadow( 12px 0 24px rgba(0,0,0,0.35))
[class*="glass"] {
  width: min(640px, 80vw);
  min-height: 90vh;
  margin: 5vh auto;
  padding: 12px 12px 48px;
  text-align: center;
  background: rgba(255,255,255,0.5);
  backdrop-filter: blur(12px) saturate(200%);
  -webkit-backdrop-filter: blur(12px) saturate(200%);
  border: solid 2px rgba(255,255,255,0.2);
  border-radius: 24px;
  box-shadow: 4px 4px 24px rgba(0,0,0,0.25);
  color: #DEF;
  background: rgba(0,0,0,0.5);  
[class*="dark"] :is(h1,a) {
  color: #F93;
  text-shadow: 0 0 6px rgba(0,0,6,0.25);
button {
  height: 48px;
  padding: 12px 24px;
  font-size: 16px;
  color: #fff;
  background: #D81;
  border-radius: 24px;
  text-shadow: 0 0 3px rgba(0,0,6,0.25);
  cursor: pointer;


                $("#switchMode").on("click", function(){
    $("#switchMode").html("Modo diurno");
  } else {
    $("#switchMode").html("Modo nocturno");