.letter-read {
  position: relative;
  background: var(--bg-alt);
  min-height: 60vh;
  padding-block: var(--space-7) var(--space-9);
}

.letter-read::after {
  content: "";
  position: absolute;
  inset: 0;
  opacity: 0.05;
  mix-blend-mode: multiply;
  pointer-events: none;
  background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='140' height='140'><filter id='n'><feTurbulence type='fractalNoise' baseFrequency='0.75' numOctaves='3'/></filter><rect width='100%25' height='100%25' filter='url(%23n)'/></svg>");
}

.letter-read__container {
  position: relative;
  max-width: 46rem;
}

.letter-read__back {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.05em;
  color: var(--ink-50);
  margin-bottom: var(--space-6);
  transition: color var(--dur-fast) var(--ease-editorial);
}

.letter-read__back:hover {
  color: var(--plum);
}

.letter-stage {
  position: relative;
  min-height: 30rem;
}

.seal-button {
  position: absolute;
  top: 4.5rem;
  left: 50%;
  transform: translateX(-50%);
  width: 9rem;
  height: 9rem;
  border: 0;
  background: none;
  cursor: pointer;
  z-index: 5;
  padding: 0;
}

.seal-button__half {
  position: absolute;
  inset: 0;
  background-size: contain;
  background-position: center;
  background-repeat: no-repeat;
  filter: drop-shadow(0 0.5rem 1rem rgba(0, 0, 0, 0.35));
}

.seal-button__half--left {
  clip-path: polygon(0 0, 50% 0, 50% 100%, 0 100%);
}

.seal-button__half--right {
  clip-path: polygon(50% 0, 100% 0, 100% 100%, 50% 100%);
}

.seal-button__hint {
  position: absolute;
  bottom: -2.25rem;
  left: 50%;
  transform: translateX(-50%);
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.08em;
  color: var(--ink-50);
  white-space: nowrap;
  transition: opacity 0.3s ease;
}

.letter-stage.is-cracking .seal-button__half--left {
  animation: seal-crack-left 0.9s cubic-bezier(0.36, 0, 0.66, 1) forwards;
}

.letter-stage.is-cracking .seal-button__half--right {
  animation: seal-crack-right 0.9s cubic-bezier(0.36, 0, 0.66, 1) forwards;
}

.letter-stage.is-cracking .seal-button__hint {
  opacity: 0;
}

.letter-stage.is-open .seal-button {
  pointer-events: none;
}

@keyframes seal-crack-left {
  0% { transform: rotate(0) translate(0, 0); opacity: 1; }
  12% { transform: rotate(-4deg); }
  24% { transform: rotate(3deg); }
  36% { transform: rotate(-3deg); }
  100% { transform: translate(-3.5rem, 2.5rem) rotate(-30deg); opacity: 0; }
}

@keyframes seal-crack-right {
  0% { transform: rotate(0) translate(0, 0); opacity: 1; }
  12% { transform: rotate(4deg); }
  24% { transform: rotate(-3deg); }
  36% { transform: rotate(3deg); }
  100% { transform: translate(3.5rem, 3rem) rotate(28deg); opacity: 0; }
}

.letter-sheet {
  position: relative;
  max-width: 34rem;
  margin: 0 auto;
  background: var(--bg);
  padding: 5.5rem var(--space-7) var(--space-7);
  box-shadow: 0 2rem 4rem -1.5rem rgba(0, 0, 0, 0.35);
  opacity: 0;
  transform: translateY(1rem);
  transition: opacity 0.7s var(--ease-editorial) 0.35s, transform 0.7s var(--ease-editorial) 0.35s;
}

.letter-sheet::after {
  content: "";
  position: absolute;
  inset: 0;
  opacity: 0.05;
  mix-blend-mode: multiply;
  pointer-events: none;
  background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='140' height='140'><filter id='n'><feTurbulence type='fractalNoise' baseFrequency='0.75' numOctaves='3'/></filter><rect width='100%25' height='100%25' filter='url(%23n)'/></svg>");
}

.letter-stage.is-open .letter-sheet {
  opacity: 1;
  transform: none;
}

/* revisiting a letter already opened this session: skip the whole
   animation, show it open immediately */
.letter-stage.is-instant .seal-button {
  display: none;
}

.letter-stage.is-instant .letter-sheet {
  transition: none;
}

.letter-like {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  margin-top: var(--space-6);
  padding: 0.6rem 1.1rem;
  border: 1px solid var(--plum);
  background: transparent;
  color: var(--plum);
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.04em;
  cursor: pointer;
  transition: background var(--dur-fast) var(--ease-editorial), color var(--dur-fast) var(--ease-editorial), transform var(--dur-fast) var(--ease-editorial);
}

.letter-like i {
  font-style: normal;
  transition: transform var(--dur-fast) var(--ease-editorial);
}

.letter-like:hover {
  background: var(--plum);
  color: var(--bg);
}

.letter-like.is-liked {
  background: var(--plum);
  color: var(--bg);
  cursor: default;
}

.letter-like.is-liked i {
  transform: scale(1.15);
}

.letter-like:disabled {
  opacity: 0.85;
}

.letter-sheet__head {
  text-align: center;
  margin-bottom: var(--space-5);
}

.letter-sheet__date {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.08em;
  color: var(--ink-50);
}

.letter-sheet__message {
  position: relative;
  font-size: 1.5rem;
  line-height: 1.6;
  color: var(--ink);
  margin-bottom: var(--space-6);
  white-space: pre-line;
}

.letter-sheet__signature {
  position: relative;
  font-size: 1.75rem;
  text-align: right;
  color: var(--plum);
  margin: 0;
}

@media (max-width: 30rem) {
  .seal-button {
    width: 6.5rem;
    height: 6.5rem;
    top: 2.5rem;
  }
  .letter-sheet {
    padding: 4.5rem 1.5rem var(--space-6);
  }
  .letter-sheet__message {
    font-size: 1.25rem;
  }
  .letter-sheet__signature {
    font-size: 1.4rem;
  }
}