:root {
  --grayish-blue: hsl(237, 18%, 59%);
  --soft-red: hsl(345, 95%, 68%);
  --white: hsl(0, 0%, 100%);
  --dark-less-desaturated-blue: hsl(236, 21%, 20%);
  --dark-desaturated-blue: hsl(236, 21%, 26%);
  --very-dark-blue: hsl(235, 16%, 14%);
  --very-black-blue: hsl(234, 17%, 12%);
}

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

body {
  font-family: 'Red Hat Display', sans-serif;
  font-size: 14px;
  font-weight: 700;
  height: 100vh;
  height: 100dvh;
  margin-inline: auto;
  color: var(--white);
  background: var(--very-dark-blue);
  overflow: hidden;
}

main {
  position: relative;
  display: flex;
  flex-direction: column;
  justify-content: center;
  height: 100%;
}

h1 {
  font-size: 2rem;
  text-align: center;
  margin-top: -0.5rem;
}

h1,
.text {
  letter-spacing: 0.2em;
}

h1,
.text,
.num {
  font-variant-caps: all-small-caps;
}

.stars {
  height: 100%;
}

.hill {
  bottom: 0;
  height: 25%;
  width: 100%;
}

@media (max-width: 710px) {
  .hill {
    width: 300%;
    left: -165%;
  }
}

.stars,
.hill {
  position: absolute;
  z-index: -1;
}

.countdown-wrapper {
  display: flex;
  flex-direction: column;
  align-items: center;
  height: 67%;
  width: 100vw;
  width: 100dvw;
}

.countdown-container {
  display: flex;
  justify-content: center;
  margin-top: 7.5em;
  gap: 1.5rem;
}

@media(max-width:710px) {
  .countdown-container {
    gap: 1rem;
  }
}

.cards-container {
  display: flex;
}

.cards {
  display: block;
  font-size: 5rem;
  height: 9rem;
}

@media(max-width:710px) {
  .cards {
    font-size: 2.25rem;
    height: 4.75rem;
  }
}

.card-element {
  position: relative;
  height: 100%;
}

.card-element__top,
.card-element__bottom {
  text-align: center;
  height: 50%;
  width: 5rem;
  overflow: hidden;
}

.card-element__top {
  padding-top: 1.1rem;
  color: var(--soft-red);
  background-color: var(--dark-less-desaturated-blue);
}

.card-element__bottom {
  padding-bottom: 1.1rem;
  line-height: 0;
  color: var(--soft-red);
  background-color: var(--dark-desaturated-blue);
  box-shadow: 0px 7px 0px 0px var(--very-black-blue);
}

.card-element-flip {
  position: absolute;
  top: 0;
  height: 100%;
}

.card-element-flip__top,
.card-element-flip__bottom {
  position: absolute;
  height: 50%;
  width: 5rem;
  text-align: center;
  overflow: hidden;
}

@media(max-width:710px) {

  .card-element__top,
  .card-element__bottom {
    width: 2.5rem;
  }

  .card-element-flip__top,
  .card-element-flip__bottom {
    width: 2.5rem;
  }
}

.card-element-flip__top {
  top: 0;
  padding-top: 1.1rem;
  color: var(--soft-red);
  background-color: var(--dark-less-desaturated-blue);
  transform-origin: bottom;
}

.card-element-flip__bottom {
  bottom: 0;
  line-height: 0;
  padding-bottom: 1.1rem;
  color: var(--soft-red);
  background-color: var(--dark-desaturated-blue);
  border-top: 1px solid var(--very-black-blue);
  transform-origin: top;
}

.cards:nth-of-type(odd) .card-element__top,
.cards:nth-of-type(odd) .card-element__bottom,
.cards:nth-of-type(odd) .card-element-flip__top,
.cards:nth-of-type(odd) .card-element-flip__bottom {
  padding-left: 1rem;
}

.cards:nth-of-type(even) .card-element__top,
.cards:nth-of-type(even) .card-element__bottom,
.cards:nth-of-type(even) .card-element-flip__top,
.cards:nth-of-type(even) .card-element-flip__bottom {
  padding-right: 1rem;
}

@media(max-width:710px) {

  .cards:nth-of-type(odd) .card-element__top,
  .cards:nth-of-type(odd) .card-element__bottom,
  .cards:nth-of-type(odd) .card-element-flip__top,
  .cards:nth-of-type(odd) .card-element-flip__bottom {
    padding-left: 1rem;
  }

  .cards:nth-of-type(even) .card-element__top,
  .cards:nth-of-type(even) .card-element__bottom,
  .cards:nth-of-type(even) .card-element-flip__top,
  .cards:nth-of-type(even) .card-element-flip__bottom {
    padding-right: 1rem;
  }
}

.cards:nth-of-type(odd) .card-element__top,
.cards:nth-of-type(odd) .card-element-flip__top {
  border-top-left-radius: 0.1em;
  background-image: radial-gradient(circle at 0% 100%, var(--very-dark-blue) 5px, transparent 5px);
}

.cards:nth-of-type(even) .card-element__top,
.cards:nth-of-type(even) .card-element-flip__top {
  border-top-right-radius: 0.1em;
  background-image: radial-gradient(circle at 100% 100%, var(--very-dark-blue) 5px, transparent 5px);
}

.cards:nth-of-type(odd) .card-element__bottom,
.cards:nth-of-type(odd) .card-element-flip__bottom {
  border-bottom-left-radius: 0.1em;
  background-image: radial-gradient(circle at 0% 0%, var(--very-dark-blue) 5px, transparent 5px);
}

.cards:nth-of-type(even) .card-element__bottom,
.cards:nth-of-type(even) .card-element-flip__bottom {
  border-bottom-right-radius: 0.1em;
  background-image: radial-gradient(circle at 100% 0%, var(--very-dark-blue) 5px, transparent 5px);
}

.card-element-flip.anim .card-element-flip__top {
  -webkit-animation: flip-top 0.9s linear;
  animation: flip-top 0.9s linear;
}

.card-element-flip.anim .card-element-flip__bottom {
  -webkit-animation: flip-bottom 0.9s linear;
  animation: flip-bottom 0.9s linear;
}

@-webkit-keyframes flip-top {
  0% {
    transform: rotateX(0deg);
  }

  50%,
  100% {
    transform: rotateX(-90deg);
  }
}

@keyframes flip-top {
  0% {
    transform: rotateX(0deg);
  }

  50%,
  100% {
    transform: rotateX(-90deg);
  }
}

@-webkit-keyframes flip-bottom {

  0%,
  50% {
    transform: rotateX(90deg);
  }

  100% {
    transform: rotateX(0deg);
  }
}

@keyframes flip-bottom {

  0%,
  50% {
    transform: rotateX(90deg);
  }

  100% {
    transform: rotateX(0deg);
  }
}

.text {
  font-size: 1.3rem;
  margin-top: 20px;
  color: var(--grayish-blue);
  width: 100%;
  text-align: center;
}

@media(max-width:710px) {
  .text {
    font-size: 0.9rem;
  }
}

.socials {
  position: absolute;
  bottom: 3rem;
}

.social-icon {
  margin: 20px 15px;
}

.social-icon path {
  fill: var(--grayish-blue);
  cursor: pointer;
}

.social-icon:hover path {
  fill: var(--soft-red);
}

.attribution {
  display: none;
  position: absolute;
  bottom: 1rem;
  font-size: 11px;
  text-align: center;
  z-index: 3;
}

.attribution a {
  color: hsl(228, 45%, 44%);
  text-decoration: none;
}