* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --prim: #1b53a8;
}

body {
  font-family: "Ubuntu", sans-serif;
  background: url("https://images.pexels.com/photos/403571/pexels-photo-403571.jpeg?auto=compress&cs=tinysrgb&w=1260&h=750&dpr=1")
    no-repeat;
  background-size: cover;
  background-position: center;
  background-attachment: fixed;
}

.header {
  background-color: var(--prim);
  margin-bottom: 20px;
  color: #fff;
}

h1 {
  text-transform: uppercase;
  margin-bottom: 10px;
}

h2,
h3 {
  text-transform: capitalize;
  text-align: center;
}

.main .form-section {
  margin: 0 auto;
  padding: 30px;
  display: flex;
  justify-content: center;
  align-items: center;
  border: 2px solid var(--prim);
  min-width: fit-content;
  max-width: 30%;
}

.main label {
  font-size: 1.2em;
}

#date,
.submit {
  margin: 40px auto;
  display: block;
}

.output {
  margin-top: 20px;
  text-transform: uppercase;
  font-weight: 800;
  font-size: 1.3em;
  animation-name: flash;
  animation-duration: 3s;
  animation-iteration-count: infinite;
}

@keyframes flash {
  0% {
    color: red;
    opacity: 0.2;
    transform: scale(0.4);
  }
  25% {
    color: magenta;
    opacity: 0.4;
    transform: scale(0.6);
  }

  50% {
    color: #000;
    opacity: 0.6;
    transform: scale(0.8);
  }
  100% {
    color: red;
    opacity: 0.8;
    transform: scale(1);
  }
}