:root {
  --header-height: 50px;
  --header-width: 500px;
  --header-num-items: 4;

  --header-link-width: calc(var(--header-width) / var(--header-num-items));


  --header-mobile-height: 100px;
  --header-mobile-width: 850px;

  --header-mobile-link-width: calc(var(--header-mobile-width) / var(--header-num-items));
  ;

}


header {
  width: 100%;
  text-align: center;
}

header nav {
  margin: 27px auto 0;

  position: relative;
  width: var(--header-width);
  height: var(--header-height);
  background-color: var(--background-color-lighter);
  border-radius: 8px;
  font-size: 0;
}

header nav a {
  line-height: 50px;
  height: 100%;
  font-size: 15px;
  display: inline-block;
  position: relative;
  z-index: 1;
  text-decoration: none;
  text-transform: uppercase;
  text-align: center;
  color: var(--font-color);
  cursor: pointer;
}

header nav .animation {
  position: absolute;
  height: 100%;
  top: 0;
  z-index: 0;
  transition: all .5s ease 0s;
  border-radius: 8px;
}

header a {
  width: var(--header-link-width);
}

header nav .start,
a:hover~.animation {
  width: var(--header-link-width);
  background-color: var(--highlight-color);
}


header nav .start-home,
a:nth-child(1):hover~.animation {
  left: 0;
  background-color: #3498db;
}

header nav .start-star,
a:nth-child(2):hover~.animation {
  left: calc(1*var(--header-link-width));
}

header nav .start-goodies,
a:nth-child(3):hover~.animation {
  left: calc(2*var(--header-link-width));
}

header nav .start-fanzone,
a:nth-child(4):hover~.animation {
  left: calc(3*var(--header-link-width));
}


/* header nav .start-games,
a:nth-child(5):hover~.animation {
  left: calc(4*var(--header-link-width));
} */




/* Portrait mode: change size */
@media (orientation: portrait) {

  header nav {
    margin: 50px auto 0;
    margin-top: 3vh;
    width: var(--header-mobile-width);
    height: var(--header-mobile-height);
  }

  header nav a {
    line-height: 100px;
    font-size: 30px;
  }

  header nav .animation {
    border-radius: 12px;
  }

  header a {
    width: var(--header-mobile-link-width);
  }

  header nav .start,
  a:hover~.animation {
    width: var(--header-mobile-link-width);
  }


  header nav .start-star,
  a:nth-child(2):hover~.animation {
    left: calc(1*var(--header-mobile-link-width));
  }

  header nav .start-goodies,
  a:nth-child(3):hover~.animation {
    left: calc(2*var(--header-mobile-link-width));
  }

  header nav .start-fanzone,
  a:nth-child(4):hover~.animation {
    left: calc(3*var(--header-mobile-link-width));
  }


  /* header nav .start-games,
  a:nth-child(5):hover~.animation {
    left: calc(4*var(--header-mobile-link-width));
  } */
}