<h2>City Nights Effect</h2>

@keyframes lights {
  0% {
    color: hsl(230, 40%, 80%);
    text-shadow:
      0 0 1em hsla(320, 100%, 50%, 0.2),
      0 0 0.125em hsla(320, 100%, 60%, 0.3),
      -1em -0.125em 0.5em hsla(40, 100%, 60%, 0),
      1em 0.125em 0.5em hsla(200, 100%, 60%, 0);
  }
  
  30% { 
    color: hsl(230, 80%, 90%);
    text-shadow:
      0 0 1em hsla(320, 100%, 50%, 0.5),
      0 0 0.125em hsla(320, 100%, 60%, 0.5),
      -0.5em -0.125em 0.25em hsla(40, 100%, 60%, 0.2),
      0.5em 0.125em 0.25em hsla(200, 100%, 60%, 0.4);
  }
  
  40% { 
    color: hsl(230, 100%, 95%);
    text-shadow:
      0 0 1em hsla(320, 100%, 50%, 0.5),
      0 0 0.125em hsla(320, 100%, 90%, 0.5),
      -0.25em -0.125em 0.125em hsla(40, 100%, 60%, 0.2),
      0.25em 0.125em 0.125em hsla(200, 100%, 60%, 0.4);
  }
  
  70% {
    color: hsl(230, 80%, 90%);
    text-shadow:
      0 0 1em hsla(320, 100%, 50%, 0.5),
      0 0 0.125em hsla(320, 100%, 60%, 0.5),
      0.5em -0.125em 0.25em hsla(40, 100%, 60%, 0.2),
      -0.5em 0.125em 0.25em hsla(200, 100%, 60%, 0.4);
  }
  
  100% {
    color: hsl(230, 40%, 80%);
    text-shadow:
      0 0 1em hsla(320, 100%, 50%, 0.2),
      0 0 0.125em hsla(320, 100%, 60%, 0.3),
      1em -0.125em 0.5em hsla(40, 100%, 60%, 0),
      -1em 0.125em 0.5em hsla(200, 100%, 60%, 0);
  }
  
}

body {
  margin: 0;
  font: 100% / 1.5 Raleway, sans-serif;
  color: hsl(230, 100%, 95%);
  background: linear-gradient(135deg, hsl(230, 40%, 12%), hsl(230, 20%, 7%));
  height: 100vh;
  display: flex;
}

h2 {
  margin: auto;
  font-size: 3.5rem;
  font-weight: 300;
  animation: lights 5s 750ms linear infinite;
}