style.css

html {
  line-height: 1.15;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  font-family: Seravek, "Gill Sans Nova", Ubuntu, Calibri, "DejaVu Sans", source-sans-pro, sans-serif;
}

@media (prefers-color-scheme: dark) {
  body {
    background-color: #031a50;
    color: #ffffff;
  }
}

a {
  color: #fff;
  text-decoration: none;
}

h1,
p {
  margin: 0;
  padding: 0;
  text-align: center;
}

h1 {
  font-size: 3rem;
  line-height: 1;
}

p {
  font-size: 2rem;
  font-weight: 300;
  letter-spacing: -0.25px;
}

.container {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  height: 100vh;
  max-width: 640px;
  margin: 0 auto;
}

#app {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
  margin-top: 2.5rem;
  padding: 0 1rem;
}

section {
  display: flex;
  margin-top: 2rem;
}

button {
  font-size: 1.55rem;
  font-family: inherit;
  line-height: 1.15;
  margin: 0 0.5rem;
  cursor: pointer;
  border-radius: 6px;
  background: #003b8f;
  color: #b7d5ff;
  border: 1px solid #084c86;
  padding: 1rem;
  transition: background 100ms ease-in-out;
  min-width: 150px;
}

button:hover {
  background: #0a3c81;
}

.fadeIn {
  animation: fadeInAnimation 0.5s ease-in;
}

@keyframes fadeInAnimation {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

.fadeOut {
  animation: fadeOutAnimation 0.5s ease-in;
}

@keyframes fadeOutAnimation {
  from {
    opacity: 1;
  }
  to {
    opacity: 0;
  }
}