/* ===== DARK OVERLAY ===== */
.overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, .78); /* solid fallback when backdrop-filter unavailable */
  z-index: 10;
  transition: opacity .8s ease;
}

@supports (backdrop-filter: blur(1px)) or (-webkit-backdrop-filter: blur(1px)) {
  .overlay {
    background: rgba(0, 0, 0, .6);
    backdrop-filter: blur(3px);
    -webkit-backdrop-filter: blur(3px);
  }
}

/* ===== FLOATING ENVELOPE CONTAINER ===== */
.envelope {
  position: relative;
  z-index: 20;
  width: min(280px, 82vw);      /* shrinks gracefully on small phones */
  cursor: pointer;
  touch-action: manipulation;   /* removes 300 ms tap delay on mobile */
  transition: opacity .7s ease, transform .7s ease;
  animation: floatEnvelope 3.5s ease-in-out infinite;
  perspective: 700px;
}

.envelope:hover {
  animation-play-state: paused;
  filter:
    drop-shadow(0 28px 48px rgba(255, 70, 110, .7))
    drop-shadow(0  0  20px rgba(255, 140, 180, .45));
  transform: scale(1.03);
}

/* ===== SVG ENVELOPE ===== */
.envelope-svg {
  display: block;
  width: 100%;
  overflow: visible;
  /* no scale — keeps flap fold perfectly aligned */
}

/* Flap folds open on hover **and** on tap (active state for touch devices).
   Pivot is at the hinge line where the flap meets the body (SVG y=22).
   fill-box top = y=8, bottom = y=112  →  (22-8)/(112-8) = 13.5% from top  */
.svg-flap {
  transform-box: fill-box;
  transform-origin: 50% 13.5%;
  transition: transform .55s cubic-bezier(0.4, 0, 0.2, 1);
}

.envelope:hover .svg-flap,
.envelope:active .svg-flap {
  transform: perspective(600px) rotateX(-172deg);
}

/* Seal gently pulses with a glow */
.svg-seal {
  animation: sealPulse 2.4s ease-in-out infinite;
  transform-box: fill-box;
  transform-origin: 50% 50%;
  filter: drop-shadow(0 0 0px rgba(255, 77, 109, 0));
}

/* Shimmering light sweep */
.envelope::before {
  content: '';
  position: absolute;
  left: 4px;
  top: 22px;
  width: calc(100% - 8px);
  height: calc(100% - 50px);
  background: linear-gradient(
    112deg,
    transparent 22%,
    rgba(255, 255, 255, .32) 50%,
    transparent 78%
  );
  transform: translateX(-180%);
  animation: envShimmer 4.5s ease-in-out infinite;
  border-radius: 10px;
  pointer-events: none;
  z-index: 25;
}

/* Label */
.envelope-label {
  text-align: center;
  margin-top: .55rem;
  font-size: .82rem;
  font-weight: 600;
  color: rgba(255, 200, 215, .7);
  letter-spacing: .07em;
  text-transform: uppercase;
  transition: color .3s, letter-spacing .3s;
}

.envelope:hover .envelope-label {
  color: rgba(255, 200, 215, 1);
  letter-spacing: .12em;
}

/* ===== KEYFRAMES ===== */
@keyframes floatEnvelope {
  0%, 100% { transform: translateY(0px); }
  50%       { transform: translateY(-16px); }
}

@keyframes sealPulse {
  0%, 100% { transform: scale(1);    filter: drop-shadow(0 0 0px   rgba(255, 77, 109, 0)); }
  50%       { transform: scale(1.1);  filter: drop-shadow(0 0 10px  rgba(255, 77, 109, .55)); }
}

@keyframes envShimmer {
  0%        { transform: translateX(-180%); }
  40%, 100% { transform: translateX(220%); }
}

/* ===== MOBILE RESPONSIVE ===== */
@media (max-width: 480px) {
  .envelope { width: min(250px, 88vw); }
  .envelope-label { font-size: .74rem; letter-spacing: .05em; }
}

/* Landscape phone: tighter float, smaller envelope */
@media (max-height: 520px) and (orientation: landscape) {
  .envelope { width: min(210px, 48vw); }

  @keyframes floatEnvelope {
    0%, 100% { transform: translateY(0); }
    50%       { transform: translateY(-7px); }
  }
}