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

body {
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
  margin: 0;
  background-color: #ffd6e8;
}

.message {
  position: absolute;
  top: 25%;
  left: 50%;
  padding: 10px 50px;
  border-radius: 50px;
  transform: translateX(-50%);
  font-family: "Arial", sans-serif;
  font-size: 20px;
  font-weight: bold;
  color: rgb(168, 56, 56);
  background-color: white;
  z-index: 10;
}

.envelope {
  position: relative;
  width: 300px;
  height: 200px;
  background-color: #f57b7d;
  border-radius: 10px;
  overflow: hidden;
  cursor: pointer;
  transition: 0.8s;
}

.envelope.open {
  transform: rotateX(180deg);
}

.cover {
  position: absolute;
  width: 100%;
  height: 100%;
  background-color: #ed4e51;
  transform-origin: top;
  transition: 0.8s;
}

.envelope.open .cover {
  transform: rotateX(-180deg);
}

.letter {
  position: absolute;
  display: flex;
  justify-content: center;
  align-items: center;
  top: 50%;
  left: 50%;
  width: 80%;
  height: 60%;
  transform: translate(-50%, -50%);
  background-color: white;
  border-radius: 10px;
  font-family: "Arial", sans-serif;
  font-size: 22px;
  font-weight: bold;
  color: #ed4e51;
  opacity: 0;
  transition: 0.4s, 0.8s;
}

.envelope.open .letter {
  opacity: 1;
  transform: translate(-50%, -50%) rotateX(180deg);
}

.heart {
  position: absolute;
  top: 50%;
  left: 50%;
  width: 50px;
  height: 50px;
  background-color: white;
  transform: translate(-50%, -50%) rotate(45deg);
  transform-origin: center;
}

.heart::before,
.heart::after {
  content: "";
  position: absolute;
  width: 50px;
  height: 50px;
  background-color: white;
  border-radius: 50%;
}

.heart::before {
  top: -25px;
  left: 0;
}

.heart::after {
  top: 0;
  left: -25px;
}