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HTML

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CSS

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JavaScript

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Babel includes JSX processing.

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HTML 

              
                  <link href='https://fonts.googleapis.com/css?family=Solitreo' rel='stylesheet'>

<div class="container">
  <div class="envelope"></div>
  <div class="card">
    <h1 class="message">Roses are red,<br>Violets are blue,<br>Unexpected '{'<br>on line 32.</h1>
    <div class="heart"></div>
  </div>
  <div class="cover"></div>
  <div class="lid"></div>
  <div class="shadow"></div>
</div>
!

CSS 

              
                $background: #fee2e9;
$light-pink: #fcbbcc;
$pink: #fba7bd;
$dark-pink: #f980a1;
$shadow: #e8c5d0;
$card: white;
$heart: #f40b4a;

* {
  margin: 0;
  padding: 0;
}

h1 {
  font-family: Solitreo;
}

body {
  height: 100vh;
  width: 100vw;
  background: $background;
  font-family: "Pangolin", cursive;
  font-size: 1vmin;
  display: flex;
  align-items: center;
  justify-content: center;
}

.container {
  position: relative;
  top: 0vmin;
}

.envelope {
  position: relative;
  background: $dark-pink;
  height: 30vmin;
  width: 47.9vmin;
}

.card {
  position: absolute;
  background: $card;
  height: 25vmin;
  width: 43vmin;

  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  left: 2.5vmin;
  top: 0vmin;

  animation: slide-rev 0.2s ease-out;
}

.message {
  position: absolute;
  top: 5vmin;
}

.cover {
  position: absolute;
  height: 0;
  width: 0;

  border-bottom: 15vmin solid $pink;
  border-left: 24vmin solid transparent;
  border-right: 24vmin solid transparent;
  top: 15vmin;
  z-index: 3;
}

.cover::after {
  /*left triangle*/
  position: absolute;
  content: "";
  border-left: 24.5vmin solid $light-pink;
  border-bottom: 15vmin solid transparent;
  border-top: 15vmin solid transparent;
  top: -15vmin;
  left: -24vmin;
}

.cover::before {
  position: absolute;
  content: "";
  border-right: 24.5vmin solid $light-pink;
  border-bottom: 15vmin solid transparent;
  border-top: 15vmin solid transparent;
  top: -15vmin;
  left: -0.5vmin;
}

.lid {
  position: absolute;
  height: 0;
  width: 0;

  border-top: 15vmin solid $dark-pink;
  border-left: 24vmin solid transparent;
  border-right: 24vmin solid transparent;

  top: 0;
  transform-origin: top;
  animation: open-rev 2s;
}

.container:hover .lid {
  animation: open 0.5s;
  animation-fill-mode: forwards;
}

.container:hover .card {
  animation: slide 0.2s;
  animation-delay: 0.5s;
  animation-fill-mode: forwards;
}

.shadow {
  position: relative;
  top: 3vmin;
  border-radius: 50%;
  opacity: 0.7;
  height: 2vmin;
  width: 48vmin;
  background: $shadow;
}

.heart {
  position: relative;
  width: 5vmin;
  height: 4vmin;
  top: 7vmin;
  left: -1vmin;
}
.heart:before,
.heart:after {
  position: absolute;
  content: "";
  left: 2.5vmin;
  top: 7vim;
  width: 2.5vmin;
  height: 4vmin;
  background: $heart;
  border-radius: 2.5vmin 2.5vmin 0 0;
  transform: rotate(-45deg);
  transform-origin: 0 100%;
}
.heart:after {
  left: 0;
  transform: rotate(45deg);
  transform-origin: 100% 100%;
}

@keyframes open {
  100% {
    transform: rotatex(180deg);
  }
}

@keyframes slide {
  100% {
    transform: translatey(-15vmin);
    z-index: 2;
  }
}

@keyframes open-rev {
  from {
    transform: rotatex(-180deg);
  }
}

@keyframes slide-rev {
  from {
    transform: translatey(-15vmin);
  }
}
!

JS 

              
                // By: Emily Bayuk @thestemdiaries
!
999px

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