style.css

@import url('https://fonts.googleapis.com/css2?family=PT+Sans+Narrow:wght@400;700&display=swap');

* {
  box-sizing: border-box;
}

body {
  background: #0b3747 url('https://images.unsplash.com/photo-1513279922550-250c2129b13a?ixid=MXwxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHw%3D&ixlib=rb-1.2.1&auto=format&fit=crop&w=1350&q=80') no-repeat center center/cover;
  color: rgba(255,255,255,0.87);
  font-family: "PT Sans Narrow", sans-serif;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  height: 100vh;
  overflow: hidden;
  margin: 0;
}

body::after {
  content: '';
  background-color: rgba(0,0,0,0.5);
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}

body * {
  z-index: 1;
}

h1 {
  font-size: 2.75rem;
  margin: -100px 0 30px;
}

.year {
  font-size: 12rem;
  z-index: -1;
  opacity: 0.2;
  position: absolute;
  top: 1.25rem;
  left: 50%;
  transform: translateX(-50%);
}

.countdown {
  display: none;
  transform: scale(2);
}

.time {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  margin: 0.25rem;
}

.time h2 {
  font-size: 0.75rem;
  margin: 0;
}

.time p {
  font-size: 0.75rem;
  margin: 0;
  padding: 0;
}

@media (min-width: 640px) {
  h1 {
    font-size: 3.5rem;
  }
  .time {
    margin: 1rem;
  }
  .time h2 {
    font-size: 1.5rem;
    margin: 0 0 5px;
  }
  .time p {
    font-size: 1rem;
  }
}