body {
  margin: 0;
  font-family: 'Georgia', serif;
  background: #000000;
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
}

.letter-scene {
  perspective: 1000px;
  position: relative;
}

.letter-flip {
  width: 400px;
  height: 250px;
  transition: transform 1s;
  transform-style: preserve-3d;
  cursor: pointer;
  position: relative;
}

.letter-side {
  position: absolute;
  width: 100%;
  height: 100%;
  background: #fffaf3;
  border: 1px solid #d6c8b0;
  box-shadow: 0 10px 25px rgba(0,0,0,0.1);
  display: flex;
  justify-content: center;
  align-items: center;
  backface-visibility: hidden;
  border-radius: 12px;
  text-align: center;
  padding: 1rem;
}

.front {
  font-size: 1.2rem;
}

.back {
  transform: rotateY(180deg);
  flex-direction: column;
}

.back img {
  width: 80px;
  margin-bottom: 1rem;
}

.back-note {
  font-style: italic;
  font-size: 0.9rem;
  color: #444;
}

.letter-flip.flipped {
  transform: rotateY(180deg);
}

.letter-open {
  display: none;
  max-width: 600px;
  background: #fffaf3;
  padding: 2rem;
  border-radius: 12px;
  border: 1px solid #d6c8b0;
  box-shadow: 0 10px 25px rgba(0,0,0,0.1);
  line-height: 1.6;
  text-align: left;
  animation: fadeIn 1s ease forwards;
  margin-top: 2rem;
  color: #3b2f2f;
  position: relative;
  overflow: visible;
}

.letter-open.show {
  display: block;
}

.links {
  margin-top: 2rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.links a {
  text-decoration: none;
  color: #5a3e36;
  font-weight: bold;
}

.links a:hover {
  color: #b34c4c;
}

.signature {
  margin-top: 2rem;
  font-style: italic;
  text-align: right;
}

.letter-side.front {
  flex-direction: column;
  align-items: flex-start;
  padding: 1.5rem;
}

.letter-meta {
  font-size: 0.85rem;
  color: #5a4b44;
  margin-bottom: 2rem;
}

.intro-message {
  font-size: 1.2rem;
  align-self: center;
  margin-top: auto;
  margin-bottom: auto;
  text-align: center;
  width: 100%;
}

.stamp {
  position: absolute;
  top: 1rem;
  right: 1rem;
  width: 60px;
  height: 60px;
  pointer-events: none;
}

.stamp img {
  width: 100%;
  height: auto;
  object-fit: contain;
  opacity: 0.9;
  filter: drop-shadow(1px 1px 2px rgba(0,0,0,0.2));
  transform: rotate(-5deg);
}

.paperclip {
  position: absolute;
  top: 0.5rem;
  right: -1.5rem;
  width: 48px;
  height: auto;
  cursor: pointer;
  z-index: 5;
  transition: transform 0.2s ease;
}

.paperclip img {
  width: 100%;
  height: auto;
  display: block;
  transform: rotate(12deg);
  filter: drop-shadow(1px 1px 1px rgba(0, 0, 0, 0.2));
}

.paperclip:hover {
  transform: scale(1.1);
}

.letter-extra {
  display: none;
  position: absolute;
  top: 0;
  margin-top: 30px;
  left: calc(100% + 20px);
  max-width: 500px;
  background: #fffaf3;
  padding: 1.25rem 1.75rem;
  border-radius: 12px;
  border: 1px solid #d6c8b0;
  box-shadow: 0 15px 30px rgba(0,0,0,0.2);
  animation: fadeIn 0.5s ease forwards;
  color: #3b2f2f;
  font-size: 0.8rem;
  line-height: 1.4;
  z-index: 10;
}

.letter-extra.show {
  display: block;
}

.letter-extra h2 {
  font-size: 1.2rem;
  margin-bottom: 1rem;
  color: #3b2f2f;
}

.letter-extra h3 {
  font-size: 1rem;
  margin-top: 1.2rem;
  margin-bottom: 0.3rem;
  color: #5a4b44;
}

.letter-extra ul {
  margin: 0;
  padding: 0;
  margin-bottom: 1rem;
  list-style: none;
}

.letter-extra li {
  margin: 0.3rem 0;
}

.letter-extra a {
  text-decoration: none;
  color: #5a3e36;
  font-weight: normal;
  font-size: 0.85rem;
}

.letter-extra a:hover {
  color: #b34c4c;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(15px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}