:root {
  --scroll-p: 0;
  --pointer-x: 50vw;
  --pointer-y: 35vh;

  --blue-deep: #070d1a;
  --blue-mid: #0c182d;
  --blue-soft: #132542;
  --ink-light: #e5edf8;
  --ink-muted: rgba(203, 221, 245, 0.6);
  --accent-blue: #9fc4ec;

  --paper-front: #eef3f9;
  --paper-back: #e4ecf6;
  --paper-ink: #1e2e45;
  --paper-ink-soft: rgba(30, 46, 69, 0.58);

  --font-serif: "Lora", Georgia, "Times New Roman", serif;
  --font-hand: "Caveat", cursive, sans-serif;
  --font-sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  background-color: var(--blue-deep);
}

body {
  min-height: 100%;
  min-height: 100dvh;
  overflow-x: hidden;
  color: var(--ink-light);
  font-family: var(--font-serif);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  -webkit-tap-highlight-color: transparent;
  background:
    radial-gradient(
      120% 80% at 50% calc(15% + var(--scroll-p) * 55%),
      rgba(36, 74, 128, 0.34),
      transparent 70%
    ),
    linear-gradient(
      180deg,
      var(--blue-deep) 0%,
      var(--blue-mid) 52%,
      var(--blue-soft) 100%
    );
  background-attachment: fixed;
}

/* Textura sutil de papel escuro */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 1;
  opacity: 0.032;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.8' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}

#sky-canvas {
  position: fixed;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 0;
}

.ambient-light {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 1;
  background: radial-gradient(
    460px circle at var(--pointer-x) var(--pointer-y),
    rgba(130, 178, 232, 0.075),
    transparent 68%
  );
}

/* Coluna da carta */
.letter-page {
  position: relative;
  z-index: 2;
  width: 100%;
  max-width: 540px;
  margin: 0 auto;
  padding: max(68px, calc(env(safe-area-inset-top) + 44px))
    clamp(22px, 6vw, 34px)
    max(110px, calc(env(safe-area-inset-bottom) + 72px));
}

.letter-opening {
  font-family: var(--font-hand);
  font-size: clamp(2rem, 7vw, 2.5rem);
  font-weight: 500;
  color: var(--accent-blue);
  margin-bottom: clamp(26px, 6vw, 38px);
  line-height: 1.2;
}

.letter-flow {
  display: flex;
  flex-direction: column;
  gap: clamp(34px, 8vw, 52px);
}

/* Entrada suave conforme rola */
.flow-item {
  opacity: 0;
  transform: translateY(18px);
  transition:
    opacity 0.9s cubic-bezier(0.22, 1, 0.36, 1),
    transform 0.9s cubic-bezier(0.22, 1, 0.36, 1);
}

.flow-item.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* Blocos de texto */
.text-block {
  display: flex;
  flex-direction: column;
  gap: 1.25em;
}

.letter-paragraph {
  font-family: var(--font-serif);
  font-size: clamp(1.06rem, 4.1vw, 1.22rem);
  line-height: 1.82;
  color: var(--ink-light);
  letter-spacing: 0.004em;
}

/* Polaroids interativas */
.polaroid-wrap {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 8px 0;
}

.polaroid-card {
  --tilt: -1.8deg;
  --rx: 0deg;
  --ry: 0deg;
  position: relative;
  width: min(84vw, 332px);
  perspective: 1100px;
  cursor: pointer;
  outline: none;
  transform: rotate(var(--tilt));
  transition: transform 0.55s cubic-bezier(0.22, 1, 0.36, 1);
}

.polaroid-card:hover {
  transform: rotate(0deg) translateY(-3px);
}

.polaroid-card:focus-visible .polaroid-inner {
  box-shadow:
    0 0 0 2px var(--accent-blue),
    0 22px 46px rgba(2, 6, 16, 0.55);
}

.polaroid-inner {
  position: relative;
  width: 100%;
  transform-style: preserve-3d;
  transition: transform 0.78s cubic-bezier(0.22, 1, 0.36, 1);
  transform: rotateX(var(--rx)) rotateY(var(--ry));
  box-shadow: 0 22px 46px rgba(2, 6, 16, 0.52);
  border-radius: 3px;
}

.polaroid-card.is-flipped .polaroid-inner {
  transform: rotateY(180deg);
}

.polaroid-face {
  width: 100%;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
  border-radius: 3px;
}

.polaroid-front {
  background: var(--paper-front);
  padding: 12px 12px 14px;
  display: flex;
  flex-direction: column;
}

.photo-frame {
  position: relative;
  width: 100%;
  aspect-ratio: 4 / 4.25;
  background: #cfdcf0;
  overflow: hidden;
  border-radius: 1px;
}

.photo-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  filter: contrast(0.98) saturate(0.94);
}

.photo-frame.is-missing img {
  display: none;
}

.photo-placeholder {
  position: absolute;
  inset: 0;
  display: none;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 18px;
  text-align: center;
  background: linear-gradient(145deg, #c7d7ed, #b5c9e4);
  color: rgba(24, 42, 68, 0.68);
  font-family: var(--font-sans);
  font-size: 0.78rem;
}

.photo-frame.is-missing .photo-placeholder {
  display: flex;
}

.photo-placeholder strong {
  font-weight: 500;
  color: rgba(24, 42, 68, 0.85);
}

.polaroid-caption-row {
  min-height: 36px;
  padding-top: 10px;
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 10px;
}

.polaroid-caption {
  font-family: var(--font-hand);
  font-size: clamp(1.22rem, 4.4vw, 1.38rem);
  line-height: 1.2;
  color: var(--paper-ink);
}

.flip-cue {
  font-family: var(--font-hand);
  font-size: 1rem;
  color: var(--paper-ink-soft);
  white-space: nowrap;
  flex-shrink: 0;
  transition: opacity 0.4s ease;
}

.polaroid-card.has-flipped .flip-cue {
  opacity: 0;
}

/* Verso da Polaroid */
.polaroid-back {
  position: absolute;
  inset: 0;
  transform: rotateY(180deg);
  background:
    repeating-linear-gradient(
      0deg,
      transparent,
      transparent 31px,
      rgba(56, 94, 145, 0.08) 31px,
      rgba(56, 94, 145, 0.08) 32px
    ),
    var(--paper-back);
  padding: 24px 22px 18px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.polaroid-back-note {
  margin: auto 0;
  font-family: var(--font-hand);
  font-size: clamp(1.38rem, 5vw, 1.62rem);
  line-height: 1.38;
  color: var(--paper-ink);
  text-align: left;
  overflow-y: auto;
  max-height: 100%;
  padding-right: 4px;
}

.polaroid-back-hint {
  align-self: flex-end;
  font-family: var(--font-hand);
  font-size: 1rem;
  color: var(--paper-ink-soft);
  padding-top: 10px;
}

/* Fechamento simples */
.letter-closing {
  margin-top: clamp(42px, 9vw, 60px);
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.farewell {
  font-family: var(--font-serif);
  font-size: clamp(1.06rem, 4.1vw, 1.22rem);
  line-height: 1.6;
  color: var(--ink-light);
}

.signature {
  font-family: var(--font-hand);
  font-size: clamp(1.85rem, 6.2vw, 2.35rem);
  color: var(--accent-blue);
  line-height: 1.15;
}

.footnote {
  margin-top: 8px;
  font-family: var(--font-sans);
  font-size: 0.78rem;
  color: var(--ink-muted);
  letter-spacing: 0.03em;
}

@media (max-width: 520px) {
  .ambient-light {
    opacity: 0.65;
  }

  .polaroid-card:hover {
    transform: rotate(var(--tilt));
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .flow-item {
    opacity: 1;
    transform: none;
    transition: none;
  }

  .polaroid-inner,
  .polaroid-card {
    transition: none;
  }
}