* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: "Aldrich", sans-serif;
  background: linear-gradient(135deg, #fff0f7 0%, #ffd7e8 45%, #ffe9c9 100%);
  color: #5a1d35;
}

#envelope-container {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  cursor: pointer;
  text-align: center;
}

#envelope-hearts {
  position: absolute;
  inset: -35px;
  overflow: visible;
  pointer-events: none;
}

.floating-heart {
  position: absolute;
  bottom: 5%;
  left: var(--heart-left);
  z-index: 2;
  font-size: var(--heart-size);
  opacity: 0;
  animation: float-heart var(--heart-duration) ease-in infinite;
  animation-delay: var(--heart-delay);
}

.floating-heart.red {
  color: #ed547b;
}

.floating-heart.green {
  color: #36a66a;
}

@keyframes float-heart {
  0% {
    opacity: 0;
    transform: translate(0, 0) scale(0.65) rotate(-12deg);
  }
  15% {
    opacity: 1;
  }
  85% {
    opacity: 0.9;
  }
  100% {
    opacity: 0;
    transform: translate(var(--heart-drift), -300px) scale(1.15) rotate(18deg);
  }
}

#envelope-container p {
  position: relative;
  z-index: 1;
  margin: 0;
  font-size: 1.5rem;
  letter-spacing: 0.08em;
}

#envelope {
  position: relative;
  z-index: 1;
  width: 220px;
  height: auto;
  filter: drop-shadow(0 15px 20px rgba(121, 25, 76, 0.18));
  transition: transform 0.25s ease;
}

#envelope-container:hover #envelope {
  transform: translateY(-5px) scale(1.02);
}

#letter-container {
  display: none;
  align-items: center;
  justify-content: center;
  width: 100%;
  padding: 2rem 0;
}

.letter-window {
  position: relative;
  width: min(92vw, 760px);
  padding: 2rem 1.5rem 1.5rem;
  border-radius: 24px;
  background: rgba(255, 255, 255, 0.7);
  border: 2px solid rgba(155, 54, 112, 0.25);
  box-shadow: 0 20px 45px rgba(129, 31, 82, 0.12);
  text-align: center;
  opacity: 0;
  transform: translateY(30px) scale(0.95);
  transition: all 0.5s ease;
}

.letter-window.open {
  opacity: 1;
  transform: translateY(0) scale(1);
}

#letter-title {
  margin: 0 0 1rem;
  font-size: clamp(1.6rem, 3.5vw, 2.5rem);
  line-height: 1.2;
  color: #8a234d;
}

.photo-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: clamp(0.55rem, 2vw, 1rem);
  max-width: 560px;
  margin: 0 auto 1.25rem;
}

.photo-card {
  position: relative;
  margin: 0;
  padding: 7px 7px 12px;
  border-radius: 10px;
  background: #fffdf9;
  box-shadow: 0 6px 14px rgba(100, 40, 68, 0.16);
  animation: photo-pop 0.65s both;
}

.photo-hearts {
  position: absolute;
  inset: -24px;
  z-index: 3;
  overflow: visible;
  pointer-events: none;
}

.photo-heart {
  position: absolute;
  top: calc(50% + var(--heart-start-y));
  left: calc(50% + var(--heart-start-x));
  z-index: 3;
  font-size: var(--heart-size);
  line-height: 1;
  color: var(--heart-color);
  opacity: 0;
  filter:
    drop-shadow(0 2px 3px rgba(108, 35, 69, 0.35))
    drop-shadow(0 0 5px rgba(255, 255, 255, 0.8));
  animation: photo-heart-burst 850ms cubic-bezier(0.16, 0.75, 0.3, 1) forwards;
}

@keyframes photo-heart-burst {
  0% {
    opacity: 1;
    transform: translate(-50%, -50%) scale(0.9) rotate(0);
  }
  15% {
    opacity: 1;
  }
  100% {
    opacity: 0;
    transform: translate(
        calc(-50% + var(--heart-x)),
        calc(-50% + var(--heart-y))
      )
      scale(1.15)
      rotate(var(--heart-rotate));
  }
}

.photo-card:nth-child(2) {
  animation-delay: 0.08s;
}

.photo-card:nth-child(3) {
  animation-delay: 0.16s;
}

.photo-card:nth-child(4) {
  animation-delay: 0.24s;
}

.photo-card:nth-child(5) {
  animation-delay: 0.32s;
}

.photo-card:nth-child(6) {
  animation-delay: 0.4s;
}

.photo-card:nth-child(odd) {
  transform: rotate(-2deg);
}

.photo-card:nth-child(even) {
  transform: rotate(2deg);
}

.photo-card:hover {
  z-index: 2;
  opacity: 1;
  transform: translateY(-5px) rotate(0) scale(1.04);
}

.photo-card img {
  position: relative;
  z-index: 2;
  display: block;
  width: 100%;
  aspect-ratio: 1;
  border-radius: 6px;
  object-fit: cover;
}

.photo-card figcaption {
  padding-top: 8px;
  color: #a32e63;
  font-family: "Aldrich", sans-serif;
  font-size: clamp(0.9rem, 2vw, 1.2rem);
  font-weight: 700;
  letter-spacing: 0.04em;
}

@keyframes photo-pop {
  from {
    opacity: 0;
    translate: 0 14px;
  }
  to {
    opacity: 1;
    translate: 0 0;
  }
}

.cat-stage {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  width: min(100%, 420px);
  min-height: 180px;
  margin: 0 auto;
}

.cat-surprise-button {
  display: block;
  padding: 0;
  border: 0;
  background: transparent;
  cursor: default;
}

.cat-surprise-button:disabled {
  pointer-events: none;
}

.letter-window.final .cat-surprise-button {
  cursor: pointer;
  animation: cat-invite 1.4s ease-in-out infinite alternate;
}

.letter-window.final .cat-surprise-button:hover {
  transform: scale(1.06);
}

#letter-cat {
  width: 180px;
  height: auto;
  display: block;
  margin: 0 auto;
}

.cat-prompt {
  position: absolute;
  left: calc(50% + 105px);
  top: 50%;
  width: min(190px, 42vw);
  padding: 10px 13px;
  border: 2px solid rgba(155, 54, 112, 0.25);
  border-radius: 16px 16px 16px 4px;
  background: #fffdf9;
  box-shadow: 0 7px 18px rgba(100, 40, 68, 0.14);
  color: #8a234d;
  font-size: 0.88rem;
  line-height: 1.4;
  opacity: 0;
  pointer-events: none;
  transform: translateY(-50%) translateX(-8px) scale(0.95);
  transition: opacity 0.3s ease, transform 0.3s ease;
}

.letter-window.final .cat-prompt {
  opacity: 1;
  transform: translateY(-50%) translateX(0) scale(1);
}

@keyframes cat-invite {
  from {
    transform: translateY(0) rotate(-2deg);
  }
  to {
    transform: translateY(-6px) rotate(2deg);
  }
}

#letter-buttons {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1.5rem;
  margin-top: 1.25rem;
}

.btn {
  display: inline-block;
  width: 120px;
  height: auto;
  cursor: pointer;
  transition: transform 0.2s ease;
}

.btn:hover {
  transform: scale(1.05);
}

.no-wrapper {
  position: relative;
}

#no-alert {
  position: fixed;
  left: 50%;
  bottom: 24px;
  z-index: 20;
  width: max-content;
  max-width: min(90vw, 420px);
  padding: 14px 20px;
  border: 2px solid #f08aa5;
  border-radius: 18px;
  background: #fff8fb;
  box-shadow: 0 10px 28px rgba(129, 31, 82, 0.2);
  color: #8a234d;
  font-family: "Aldrich", sans-serif;
  font-size: 0.95rem;
  line-height: 1.5;
  text-align: center;
  opacity: 0;
  pointer-events: none;
  transform: translate(-50%, 16px) scale(0.95);
  transition: opacity 0.25s ease, transform 0.25s ease;
}

#no-alert.visible {
  opacity: 1;
  transform: translate(-50%, 0) scale(1);
}

.final-text {
  margin: 1.5rem auto 0;
  max-width: 420px;
  font-size: 1.1rem;
  line-height: 1.7;
  color: #4d1d2d;
}

.letter-window.final {
  border-color: rgba(145, 44, 98, 0.5);
  box-shadow: 0 25px 50px rgba(120, 20, 72, 0.18);
}

@media (max-width: 480px) {
  .letter-window {
    padding: 1.5rem 1rem 1.25rem;
  }

  .photo-card {
    padding: 5px 5px 9px;
  }

  .btn {
    width: 105px;
  }

  .cat-stage {
    min-height: 155px;
  }

  #letter-cat {
    width: 145px;
  }

  .cat-prompt {
    left: calc(50% + 78px);
    width: min(150px, 40vw);
    padding: 8px 10px;
    font-size: 0.75rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
  }
}