body {
  margin: 0;
  height: 100vh;
  background: linear-gradient(135deg, #ff9a9e, #fad0c4);
  display: flex;
  justify-content: center;
  align-items: center;
  font-family: cursive;
  overflow: hidden;
}

/* Floating Hearts */
.hearts::before {
  content: "💖 💕 💗 💓 💞";
  position: absolute;
  width: 100%;
  font-size: 2rem;
  animation: float 10s linear infinite;
}

@keyframes float {
  0% { transform: translateY(100vh); }
  100% { transform: translateY(-100vh); }
}

/* Envelope */
.envelope-container {
  cursor: pointer;
  perspective: 1000px;
}

.envelope {
  width: 300px;
  height: 200px;
  background: #ff4e50;
  position: relative;
  border-radius: 10px;
  transition: 1s;
}

.flap {
  position: absolute;
  width: 100%;
  height: 100px;
  background: #ff1e56;
  top: 0;
  transform-origin: top;
  transition: transform 1s;
}

.letter {
  position: absolute;
  width: 90%;
  height: 90%;
  background: white;
  top: 5%;
  left: 5%;
  border-radius: 10px;
  padding: 15px;
  box-sizing: border-box;
  text-align: center;
  opacity: 0;
  transition: opacity 1s 0.5s;
}

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

.envelope.open .letter {
  opacity: 1;
}

/* Buttons */
button {
  background: #ff4e50;
  border: none;
  padding: 8px 15px;
  border-radius: 20px;
  color: white;
  cursor: pointer;
  margin-top: 10px;
  transition: 0.3s;
}

button:hover {
  transform: scale(1.1);
  background: #ff1e56;
}

/* Final Popup */
.final-popup {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(255, 0, 80, 0.8);
  display: none;
  justify-content: center;
  align-items: center;
  color: white;
  text-align: center;
}

.popup-content {
  animation: zoomIn 1s ease;
}

@keyframes zoomIn {
  from { transform: scale(0); }
  to { transform: scale(1); }
}