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

body {
  background-color: #282828;
  font-family: "Ubuntu", sans-serif;
  position: relative;
  color: #fff;
}

h1 {
  font-size: 5rem;
}

h2 {
  font-size: 3rem;
}

p {
  font-size: 1.25rem;
}

main, 
.shadow {
  min-height: 100vh;
  padding: 1rem;
}

main, 
.popup {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  align-items: center;
  justify-content: center;
}

.popup {
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  background-color: #202020;
  padding: 2rem;
  z-index: -1;
  opacity: 0;
  width: 320px;
}

.shadow {
  top: 0;
  left: 0;
  position: fixed;
  width: 100%;
  background-color: #000000db;
  z-index: -1;
  opacity: 0;
  pointer-events: none;
}

.popup.active, 
.shadow.active {
  transition: all ease .3s;
  opacity: 1;
}

.popup.active {
  z-index: 2;
}

.shadow.active {
  z-index: 1;
}

.popup, 
button {
  border-radius: .5rem;
}

button {
  padding: 1rem;
  display: block;
  width: 200px;
  border: none;
  font-size: 1.25rem;
  cursor: pointer;
}