/*
 * Shared mechanics for the wedding invitation pages. Each variant sets the
 * look through these custom properties and its own stylesheet:
 *
 *   envelope   --env-backdrop --env-paper --env-flap --env-liner --env-card --env-ink
 *   seal       --seal --seal-hi --seal-lo --seal-font
 *   photos     --grade-filter --grade-overlay --grade-blend --grain
 */

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
html, body { overflow-x: clip; }
body { margin: 0; }
img, svg { display: block; max-width: 100%; }
.hide { display: none !important; }
.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }

/* Guest-specific vs generic copy */
.when-guest { display: none; }
html.has-guest .when-guest { display: revert; }
html.has-guest .when-generic { display: none; }

/* ---------- Envelope ---------- */
#envelope { display: none; }
html.env-locked { overflow: hidden; }
html.env-locked #envelope {
  display: flex; position: fixed; inset: 0; z-index: 100;
  align-items: center; justify-content: center;
  background: var(--env-backdrop);
  padding: 24px 16px;
  transition: opacity 0.7s ease;
}
#envelope[hidden] { display: none !important; }
#envelope.is-fading { opacity: 0; pointer-events: none; }

.env-stage {
  display: flex; flex-direction: column; align-items: center; gap: 26px;
  transition: transform 0.8s cubic-bezier(.2,.7,.2,1), opacity 0.7s ease;
}
#envelope.is-fading .env-stage { transform: translateY(-30px) scale(1.06); opacity: 0; }

.env {
  position: relative;
  width: min(540px, 88vw);
  aspect-ratio: 1.5;
  perspective: 1600px;
  filter: drop-shadow(0 22px 34px rgba(0,0,0,0.28)) drop-shadow(0 4px 8px rgba(0,0,0,0.12));
  animation: env-in 0.9s cubic-bezier(.2,.7,.2,1) both;
}
@keyframes env-in { from { transform: translateY(24px) rotate(-1.5deg); opacity: 0; } to { transform: none; opacity: 1; } }

.env-back { position: absolute; inset: 0; background: var(--env-liner); border-radius: 4px; }
.env-card {
  position: absolute; left: 5%; right: 5%; top: 5%; height: 90%;
  background: var(--env-card); color: var(--env-ink);
  border-radius: 2px; z-index: 2;
  box-shadow: 0 1px 0 rgba(0,0,0,0.04);
  transition: transform 1s cubic-bezier(.25,.8,.25,1);
  display: flex; flex-direction: column; align-items: center; justify-content: flex-start;
  padding-top: 7%; text-align: center; overflow: hidden;
}
#envelope.is-card .env-card { transform: translateY(-58%); }

.env-pocket {
  position: absolute; inset: 0; z-index: 3;
  background: var(--env-paper);
  clip-path: polygon(0 0, 50% 54%, 100% 0, 100% 100%, 0 100%);
  border-radius: 4px;
}
/* side and bottom folds, shaded so the paper reads as folded */
.env-pocket::before, .env-pocket::after { content: ""; position: absolute; inset: 0; }
.env-pocket::before { clip-path: polygon(0 0, 50% 54%, 0 100%); background: linear-gradient(100deg, rgba(0,0,0,0.05), rgba(0,0,0,0)); }
.env-pocket::after  { clip-path: polygon(100% 0, 50% 54%, 100% 100%); background: linear-gradient(260deg, rgba(0,0,0,0.07), rgba(0,0,0,0)); }

.env-address {
  position: absolute; left: 0; right: 0; bottom: 7%; z-index: 1;
  text-align: center; color: var(--env-ink); padding: 0 10%;
}

.env-flap {
  position: absolute; left: 0; right: 0; top: 0; height: 58%; z-index: 4;
  transform-origin: 50% 0; transform-style: preserve-3d;
  transition: transform 0.75s cubic-bezier(.45,.05,.35,1), z-index 0s linear 0.38s;
}
.env-flap > div { position: absolute; inset: 0; clip-path: polygon(0 0, 100% 0, 50% 100%); backface-visibility: hidden; border-radius: 4px 4px 0 0; }
.env-flap-out { background: var(--env-flap); }
.env-flap-out::after { content: ""; position: absolute; inset: 0; background: linear-gradient(180deg, rgba(255,255,255,0.06), rgba(0,0,0,0.08)); }
.env-flap-in { background: var(--env-liner); transform: rotateX(180deg); }
#envelope.is-flap .env-flap { transform: rotateX(180deg); z-index: 1; }

.env-seal {
  position: absolute; left: 50%; top: 58%; z-index: 5;
  width: clamp(56px, 14%, 84px); aspect-ratio: 1;
  transform: translate(-50%, -50%);
  border: 0; padding: 0; background: none; cursor: pointer;
  border-radius: 50%;
  transition: transform 0.35s ease, opacity 0.35s ease, filter 0.2s;
  filter: drop-shadow(0 3px 4px rgba(0,0,0,0.35));
  animation: seal-pulse 2.6s ease-in-out 1.4s infinite;
}
.env-seal:hover { transform: translate(-50%, -50%) scale(1.05); }
@keyframes seal-pulse { 0%,100% { transform: translate(-50%, -50%) scale(1); } 50% { transform: translate(-50%, -50%) scale(1.045); } }
#envelope.is-opening .env-seal { animation: none; transform: translate(-50%, -50%) scale(1.3) rotate(-8deg); opacity: 0; }
.env-seal svg { width: 100%; height: 100%; }

.env-btn { transition: opacity 0.3s; }
#envelope.is-opening .env-btn, #envelope.is-opening .env-hint { opacity: 0; pointer-events: none; }
.env-hint { transition: opacity 0.3s; margin: 0; text-align: center; }

/* Page content arrives once the envelope is gone */
html.env-locked main, html.env-locked nav { visibility: hidden; }
.arrive { opacity: 0; transform: translateY(16px); transition: opacity 1s ease, transform 1s ease; }
html.opened .arrive { opacity: 1; transform: none; }
html.opened .arrive.d1 { transition-delay: 0.15s; }
html.opened .arrive.d2 { transition-delay: 0.35s; }
html.opened .arrive.d3 { transition-delay: 0.55s; }
html.opened .arrive.d4 { transition-delay: 0.75s; }
html:not(.js) .arrive { opacity: 1; transform: none; }

/* ---------- Graded photos ---------- */
.photo { position: relative; overflow: hidden; isolation: isolate; }
.photo img { width: 100%; height: 100%; object-fit: cover; filter: var(--grade-filter, none); }
.photo::after {
  content: ""; position: absolute; inset: 0; pointer-events: none;
  background: var(--grade-overlay, none); mix-blend-mode: var(--grade-blend, normal);
}
.photo::before {
  content: ""; position: absolute; inset: 0; z-index: 1; pointer-events: none;
  opacity: var(--grain, 0); mix-blend-mode: overlay;
  background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='180' height='180'><filter id='n'><feTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='2' stitchTiles='stitch'/><feColorMatrix values='0 0 0 0 0.5  0 0 0 0 0.5  0 0 0 0 0.5  0 0 0 1.2 -0.1'/></filter><rect width='100%' height='100%' filter='url(%23n)'/></svg>");
}

/* ---------- Scroll reveal ---------- */
.js .reveal { opacity: 0; transform: translateY(22px); transition: opacity 0.8s ease, transform 0.8s ease; }
.js .reveal.in { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .js .reveal, .arrive { opacity: 1 !important; transform: none !important; transition: none !important; }
  .env, .env-seal { animation: none !important; }
}