.rain {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  mask-image: linear-gradient(#000 0%, #000 72%, transparent 100%);
}

.letter-wrap {
  background: radial-gradient(ellipse at 28% 35%, #261a15, #181510 70%);
  border-block: 1px solid #47342d;
}

.letter-inner {
  display: grid;
  grid-template-columns: minmax(0, .9fr) minmax(0, 1.1fr);
  align-items: center;
  gap: clamp(32px, 7vw, 100px);
  max-width: 1250px;
  margin-inline: auto;
}

.letter-scene {
  align-self: stretch;
  min-height: 440px;
  border: 1px solid #60463b;
  background:
    linear-gradient(180deg, #25120c20, #1c100a18),
    url("assets/letter-desk.jpg") center 55% / cover,
    url("assets/photo.jpg") center / cover;
  box-shadow: 12px 12px 0 #0a090860;
}

.correspondence h2 { margin-block: 16px 32px; }

.letter {
  max-width: 580px;
  color: #302218;
  box-shadow: 0 18px 45px #06050466;
}

.envelope {
  isolation: isolate;
  position: relative;
  display: flex;
  align-items: center;
  gap: 16px;
  width: 100%;
  min-height: 104px;
  padding: 16px clamp(16px, 4vw, 28px);
  border: 1px solid #8b6953;
  border-radius: 2px;
  text-align: left;
  color: #302218;
  background:
    linear-gradient(152deg, transparent 49.8%, #4e2c2329 50%, transparent 50.6%),
    linear-gradient(24deg, #ac8864, #dbc4a1 75%);
  perspective: 500px;
}

.envelope-flap {
  z-index: -1;
  position: absolute;
  inset: 0 0 15%;
  clip-path: polygon(0 0, 100% 0, 50% 100%);
  transform-origin: top;
  background: linear-gradient(173deg, #dfc5a2, #b89067 88%);
  border-top: 1px solid #ffead48a;
  transition: transform .54s cubic-bezier(.22,.8,.3,1), opacity .42s ease;
}

.wax {
  display: grid;
  place-items: center;
  width: 49px;
  height: 46px;
  flex: 0 0 49px;
  border-radius: 47% 45% 52% 45%;
  border: 1px solid #522118;
  box-shadow: inset 0 0 0 3px #b3533b50, 0 3px 7px #37201955;
  color: #f3b3a0;
  background: radial-gradient(circle at 32% 28%, #963d31, #63231f);
  transform: rotate(-9deg);
  transition: transform .4s cubic-bezier(.2,.7,.3,1), opacity .4s ease;
}

.envelope-action { font-size: 15px; font-weight: 700; }
.envelope-arrow {
  margin-inline-start: auto;
  transition: transform .48s cubic-bezier(.22,.8,.3,1);
}
.envelope:hover .wax { transform: rotate(-2deg) scale(1.07); }
.letter.is-open .wax { transform: rotate(11deg) scale(.89); opacity: .76; }
.letter.is-open .envelope-flap { transform: rotateX(112deg); opacity: 0; }
.letter.is-open .envelope-arrow { transform: rotate(180deg); }

.letter-reveal {
  display: grid;
  grid-template-rows: 0fr;
  visibility: hidden;
  transition: grid-template-rows .55s cubic-bezier(.22,.8,.25,1), visibility .55s;
}
.letter.is-open .letter-reveal {
  grid-template-rows: 1fr;
  visibility: visible;
}
.letter-reveal-inner { overflow: hidden; min-height: 0; }
.letter-paper {
  opacity: 0;
  transform: translateY(-12px);
  padding: clamp(22px, 4vw, 36px);
  background: linear-gradient(110deg, #d2b995, #e5d2b4 56%, #d8bb97);
  border-inline: 1px solid #927458;
  border-bottom: 1px solid #927458;
  transition: opacity .26s ease, transform .47s cubic-bezier(.22,.8,.25,1);
}
.letter.is-open .letter-paper {
  opacity: 1;
  transform: translateY(0);
  transition-delay: .09s;
}
.letter-paper p { margin: 0 0 15px; line-height: 1.85; font-size: 15px; }
.letter-paper .letter-lead { font-size: 19px; font-weight: 700; }
.letter-link {
  display: inline-block;
  color: #702d23;
  font-size: 13px;
  font-weight: 700;
  padding-block: 7px;
  text-decoration: underline;
  text-underline-offset: 5px;
}

:focus-visible { outline: 2px solid #e2aa8f; outline-offset: 4px; }
.envelope:focus-visible { outline-offset: 5px; }

.wechat {
  display: grid;
  grid-template-columns: minmax(130px, 184px) minmax(0, 1fr);
  align-items: center;
  gap: clamp(14px, 2.5vw, 30px);
  margin: 34px 0 0;
  padding: clamp(12px, 2.4vw, 22px);
  border: 1px solid #75483c;
  background: linear-gradient(132deg, #32221c, #271b17 67%);
}
.qr-frame {
  position: relative;
  padding: 7px;
  border: 1px solid #a96850;
  background: #602f25;
}
.qr-frame img { display: block; width: 100%; height: auto; }
.wechat h3 { font-size: clamp(16px, 1.7vw, 21px); margin: 0 0 8px; color: #ead8ba; }
.wechat p { margin: 0; color: #c6b4a0; font-size: 13px; line-height: 1.8; }

@media (max-width: 700px) {
  .letter-inner { grid-template-columns: minmax(0, 1fr); gap: 30px; }
  .letter-scene { min-height: clamp(185px, 52vw, 310px); background-position: center 65%; box-shadow: 7px 7px 0 #0a090860; }
}

@media (max-width: 360px) {
  .wechat { grid-template-columns: minmax(0, 1fr); }
  .qr-frame { width: min(184px, 100%); }
}

@media (prefers-reduced-motion: reduce) {
  .rain { display: none; }
  .letter * { transition: none; }
}