body {
  margin: 0;
  padding: 0;
  font-family: sans-serif;
  background: #fff;
  overflow-x: hidden;
  transition: filter 0.3s;
}
button {
  position: absolute;
  top: 10px;
  right: 10px;
  font-size: 18px;
  background: #eee;
  border: none;
  padding: 10px;
  cursor: pointer;
}
.bw-mode {
  filter: grayscale(1);
}
#petal-container img {
  position: absolute;
  width: 30px;
  animation: fall linear infinite;
}
@keyframes fall {
  0% { transform: translateY(-10vh) rotate(0); opacity: 1; }
  100% { transform: translateY(110vh) rotate(360deg); opacity: 0; }
}
.ring-box {
  position: absolute;
  bottom: 100px;
  left: 50%;
  transform: translateX(-50%);
  width: 100px;
  height: 100px;
  background: #111;
  border-radius: 10px;
  display: flex;
  justify-content: center;
  align-items: center;
  animation: pop 2s ease-out forwards;
}
.ring {
  width: 50px;
  height: 50px;
  border: 5px solid gold;
  border-radius: 50%;
  background: transparent;
  opacity: 0;
  animation: appear 2s 2s forwards;
}
@keyframes appear {
  to { opacity: 1; transform: scale(1); }
}
.couple-photo {
  width: 40%;
  margin: 10px;
  border-radius: 10px;
}
.content {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  margin-top: 20px;
}