@import url("https://fonts.googleapis.com/css2?family=Quicksand:wght@300;400;500;700&display=swap");

body {
  font-family: Quicksand;
  text-align: center;
  margin-left: 5rem;
  margin-right: 5rem;
  padding: 0;
  background-color: indigo;
}

banner {
  border: 3px solid greenyellow;
  background-color: deeppink;
  display: flex;
  block-size: 10rem;
  justify-content: center;
  align-items: center;
}
nav {
  border: 3px solid whitesmoke;
  display: grid;
  grid-template-columns: 25% 25% 25% 25%;
  padding-left: 1rem;
  padding-right: 1rem;
}
main {
  border: 3px solid blue;
  display: grid;
  grid-template-columns: 25% 50% 25%;
}
footer {
  border: 3px solid purple;
  display: block;
  block-size: 5rem;
  background-color: whitesmoke;
}

column {
  border: 3px solid red;
  display: block;
  background-color: aqua;
  min-block-size: 20rem;
  padding: 1rem;
}

.link {
  color: whitesmoke;
}

.blinking {
  animation: 0.5s linear 1s infinite alternate slide-in;
}

.bouncing-v {
  background-color: yellow;
  border-radius: 50%;
  aspect-ratio: 1 / 1;
  animation: 500ms linear 0s infinite alternate bouncing-v-anim;
}

.bouncing-h {
  animation: 1s linear 0s infinite alternate bouncing-h-anim;
}

@keyframes bouncing-v-anim {
  from {
    transform: translateY(25%);
    background-color: pink;
    filter: brightness(75%);
  }
  to {
    transform: translateY(-25%);
    background-color: orange;
    /* unset properties i.e. 'filter' will revert to default values */
  }
}

@keyframes bouncing-h-anim {
  from {
    transform: translateX(10%);
  }
  to {
    transform: translateX(-10%);
  }
}