/* ===== 信封本體 ===== */
.envelope {
  position: relative;
  width: 320px;
  height: 200px;
  cursor: pointer;
  transition: transform 1.2s ease;
  transform-style: preserve-3d;
}

.envelope.open {
  transform: scale(12);
}

.envelope:not(.open):hover {
  transform: translateY(-4px);
}

/* Letter card peeking out */
.envelope-letter {
  position: absolute;
  left: 14px;
  right: 14px;
  top: 18px;
  height: 150px;
  border-radius: 14px;
  background:
    linear-gradient(180deg, rgba(255, 250, 242, 0.96), rgba(246, 240, 230, 0.96));
  border: 1px solid rgba(28, 35, 48, 0.12);
  box-shadow: 0 18px 50px rgba(0,0,0,0.22);
  transform: translateY(44px) rotate(-1.2deg);
  opacity: 0.98;
  z-index: 2;
}

.envelope-letter-inner {
  height: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 12px;
  padding: 16px 14px 12px;
}

.envelope-letter-title {
  font-family: "Cinzel", "Cormorant Garamond", ui-serif, serif;
  letter-spacing: 4px;
  font-size: 14px;
  color: rgba(28, 35, 48, 0.72);
}

.envelope-letter-line {
  width: 56px;
  height: 1px;
  background: rgba(176, 141, 87, 0.38);
}

/* 背面 */
.envelope-back {
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, #ffffff, #fbf5ea);
  border-radius: 12px;
  border: 1px solid rgba(31, 35, 40, 0.10);
  box-shadow: var(--shadow-md);
}

/* 上蓋 */
.envelope-flap {
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, #f2efe8, #e6dccd);
  clip-path: polygon(0 0, 100% 0, 50% 55%);
  transform-origin: top center;
  transition: transform 0.8s ease;
}

/* 蠟封（就加在這） */
.seal {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: radial-gradient(circle at 30% 30%, #d9bc86, var(--accent));
  padding: 3px;

  display: flex;
  align-items: center;
  justify-content: center;

  z-index: 5;
  box-shadow: 0 10px 24px rgba(0,0,0,0.25);
}

.seal::after {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: 50%;
  background:
    radial-gradient(circle at 30% 20%, rgba(255,255,255,0.55), transparent 40%),
    radial-gradient(circle at 70% 80%, rgba(255,255,255,0.18), transparent 52%);
  opacity: 0.55;
  mix-blend-mode: soft-light;
  pointer-events: none;
  animation: sealShine 3.6s ease-in-out infinite;
}

@keyframes sealShine {
  0%, 100% { opacity: 0.30; transform: rotate(0deg); }
  50% { opacity: 0.62; transform: rotate(10deg); }
}

.seal img {
  width: 100%;
  height: 100%;
  border-radius: 50%;
  object-fit: cover;
  animation: sealPortraitTurn 6.5s ease-in-out infinite;
  transform-origin: 50% 55%;
}

@keyframes sealPortraitTurn {
  0% { transform: rotate(-2deg); }
  50% { transform: rotate(2deg); }
  100% { transform: rotate(-2deg); }
}
/* 蠟封消失動畫 */
.envelope.open .seal {
  opacity: 0;
  transition: opacity 0.4s ease;
}

/* 前片 */
.envelope-front {
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, #ffffff, #f6f1e8);
  clip-path: polygon(0 100%, 50% 45%, 100% 100%);
}

/* 點擊後，上蓋翻開 */
.envelope.open .envelope-flap {
  transform: rotateX(160deg);
}

/* The "wow": letter slides out a bit before the full transition */
.envelope.open .envelope-letter {
  animation: letterSlide 820ms cubic-bezier(.2,.8,.2,1) both;
}

@keyframes letterSlide {
  0% { transform: translateY(44px) rotate(-1.2deg); }
  60% { transform: translateY(-10px) rotate(0deg); }
  100% { transform: translateY(-6px) rotate(0deg); }
}

@media (min-width: 980px) {
  .envelope {
    width: 480px;
    height: 300px;
  }

  .envelope-letter {
    left: 20px;
    right: 20px;
    top: 26px;
    height: 228px;
    transform: translateY(76px) rotate(-0.9deg);
  }

  @keyframes letterSlide {
    0% { transform: translateY(76px) rotate(-0.9deg); }
    60% { transform: translateY(-18px) rotate(0deg); }
    100% { transform: translateY(-12px) rotate(0deg); }
  }

  .seal {
    width: 84px;
    height: 84px;
    padding: 5px;
    box-shadow: 0 18px 44px rgba(0,0,0,0.26);
  }
}