:root {
  --bg: #0B0A1E;
  --bg-2: #1A1030;
  --ink: #F5F0FF;
  --ink-soft: #C9C2E8;
  --gold: #FFD9A0;
  --flame-core: #FFF3C4;
  --flame-edge: #FF9A3C;
  --violet: #8B7BD8;
  --rose: #E88FB0;
  --paper: #F7F1E3;
  --paper-ink: #3A3355;
  --font-display: "Cormorant Garamond", "Georgia", serif;
  --font-body: "Segoe UI", system-ui, -apple-system, sans-serif;
}

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

html, body {
  min-height: 100%;
  background-color: var(--bg);
  background-image: radial-gradient(120% 100% at 50% 0%, var(--bg-2), var(--bg));
  color: var(--ink);
  font-family: var(--font-body);
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

#sky {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  overflow: hidden;
}

.star {
  position: absolute;
  border-radius: 50%;
  background: var(--ink-soft);
  box-shadow: 0 0 6px rgba(245, 240, 255, 0.65);
  animation: twinkle 3s ease-in-out infinite;
}

.firefly {
  position: absolute;
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: var(--gold);
  box-shadow: 0 0 10px 3px rgba(255, 217, 160, 0.75);
  opacity: 0;
  animation: drift 11s ease-in-out infinite;
}

@keyframes twinkle {
  0%, 100% { opacity: 0.2; transform: scale(0.85); }
  50% { opacity: 1; transform: scale(1.2); }
}

@keyframes drift {
  0% {
    transform: translate(0, 0) scale(0.8);
    opacity: 0;
  }
  25% {
    opacity: 0.9;
  }
  50% {
    transform: translate(38px, -24px) scale(1.15);
    opacity: 0.85;
  }
  75% {
    opacity: 0.9;
  }
  100% {
    transform: translate(-34px, 22px) scale(0.8);
    opacity: 0;
  }
}

.scene {
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 1.5rem;
  padding: 2rem 1.25rem;
  position: relative;
  z-index: 1;
  text-align: center;
}

.scene[hidden] {
  display: none !important;
}

.gate-content {
  max-width: 420px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.25rem;
  padding: 2.25rem 1.5rem;
  border-radius: 24px;
  background: rgba(26, 16, 48, 0.55);
  border: 1px solid rgba(201, 194, 232, 0.16);
  backdrop-filter: blur(12px);
  box-shadow: 0 24px 64px rgba(0, 0, 0, 0.45);
}

.eyebrow {
  font-size: 0.78rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--gold);
  font-weight: 600;
}

#gate h1 {
  font-family: var(--font-display);
  font-size: clamp(2rem, 8vw, 3.5rem);
  font-weight: 600;
  line-height: 1.15;
  color: var(--ink);
  text-shadow: 0 4px 24px rgba(255, 217, 160, 0.22);
  overflow-wrap: anywhere;
}

.gate-subtitle {
  color: var(--ink-soft);
  font-size: 0.96rem;
  line-height: 1.5;
  max-width: 30ch;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  min-height: 48px;
  padding: 0.85rem 2rem;
  border: none;
  border-radius: 999px;
  background: linear-gradient(135deg, var(--violet), var(--rose));
  color: #ffffff;
  font-family: var(--font-body);
  font-size: 1.02rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  cursor: pointer;
  box-shadow: 0 8px 32px rgba(139, 123, 216, 0.35);
  transition: transform 180ms ease, box-shadow 180ms ease, opacity 180ms ease;
  user-select: none;
  -webkit-tap-highlight-color: transparent;
}

.btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 36px rgba(232, 143, 176, 0.45);
}

.btn .icon {
  width: 1.2rem;
  height: 1.2rem;
  flex: none;
}

.btn:active {
  transform: translateY(0) scale(0.98);
}

.btn.subtle {
  background: rgba(201, 194, 232, 0.14);
  color: var(--ink);
  border: 1px solid rgba(201, 194, 232, 0.3);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.25);
}

.btn.subtle:hover {
  background: rgba(201, 194, 232, 0.22);
}

#mute-btn {
  position: fixed;
  top: 12px;
  right: 12px;
  z-index: 20;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  border: 1px solid rgba(201, 194, 232, 0.25);
  background: rgba(11, 10, 30, 0.5);
  backdrop-filter: blur(10px);
  color: var(--ink);
  font-size: 1.2rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  box-shadow: 0 4px 18px rgba(0, 0, 0, 0.35);
  transition: transform 160ms ease, background 160ms ease;
}

#mute-btn .icon {
  width: 22px;
  height: 22px;
}

#mute-btn[hidden] {
  display: none !important;
}

#mute-btn:hover {
  background: rgba(26, 16, 48, 0.75);
  transform: scale(1.05);
}

.scene-heading {
  font-family: var(--font-display);
  font-size: clamp(1.75rem, 6.5vw, 2.75rem);
  font-weight: 600;
  color: var(--ink);
  line-height: 1.2;
  max-width: 22ch;
  text-shadow: 0 4px 20px rgba(255, 217, 160, 0.22);
  overflow-wrap: anywhere;
}

.cake-stage {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  max-width: min(90vw, 340px);
}

.cake-glow {
  position: absolute;
  inset: -24px -16px 0 -16px;
  background: radial-gradient(circle, rgba(255, 217, 160, 0.30), transparent 62%);
  pointer-events: none;
  z-index: 0;
}

#cake-svg {
  width: 100%;
  max-width: min(90vw, 340px);
  height: auto;
  position: relative;
  z-index: 1;
  overflow: visible;
}

.flame {
  transform-box: fill-box;
  transform-origin: bottom center;
  animation: flicker 1.6s ease-in-out infinite;
  transition: transform 220ms ease, opacity 180ms ease;
}

@keyframes flicker {
  0%, 100% {
    transform: scale(1) rotate(-3deg);
    opacity: 0.9;
  }
  35% {
    transform: scale(1.08, 1.04) rotate(3deg);
    opacity: 1;
  }
  70% {
    transform: scale(0.96, 1.06) rotate(4deg);
    opacity: 0.85;
  }
}

#blow-ui {
  display: none;
  flex-direction: column;
  align-items: center;
  gap: 0.9rem;
  width: 100%;
  max-width: 340px;
  padding: 1.15rem 1.25rem;
  border-radius: 18px;
  background: rgba(26, 16, 48, 0.72);
  border: 1px solid rgba(255, 217, 160, 0.22);
  backdrop-filter: blur(10px);
}

#blow-ui.visible {
  display: flex;
}

#blow-prompt {
  font-size: 0.98rem;
  color: var(--ink);
  line-height: 1.45;
}

#blow-meter {
  width: 100%;
  height: 10px;
  border-radius: 999px;
  background: rgba(11, 10, 30, 0.75);
  border: 1px solid rgba(255, 217, 160, 0.25);
  overflow: hidden;
}

#blow-meter[hidden] {
  display: none !important;
}

#blow-meter > i {
  display: block;
  height: 100%;
  width: 0%;
  border-radius: 999px;
  background: linear-gradient(90deg, var(--flame-edge), var(--gold));
  transition: width 90ms linear;
}

#fx {
  position: fixed;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 5;
}

#static-sparkles {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 5;
}

.static-sparkle {
  position: absolute;
  font-size: 1.5rem;
  opacity: 0;
  animation: sparkle-fade 1.6s ease-in-out forwards;
}

.static-sparkle .icon {
  width: 1.5rem;
  height: 1.5rem;
  color: var(--gold);
}

@keyframes sparkle-fade {
  0% { opacity: 0; transform: scale(0.7); }
  40% { opacity: 1; transform: scale(1.1); }
  100% { opacity: 0; transform: scale(1); }
}

.smoke {
  fill: none;
  stroke: rgba(200, 200, 220, 0.5);
  stroke-width: 1.8;
  stroke-linecap: round;
  transform-box: fill-box;
  transform-origin: bottom center;
  animation: smoke-rise 1.6s ease-out forwards;
}

@keyframes smoke-rise {
  0% {
    transform: translateY(0) scale(1);
    opacity: 0.8;
  }
  100% {
    transform: translateY(-26px) scale(1.6);
    opacity: 0;
  }
}

.pop-heading {
  animation: text-pop 560ms cubic-bezier(0.2, 0.9, 0.3, 1.2) forwards;
  color: var(--gold);
}

@keyframes text-pop {
  0% {
    transform: scale(0.6);
    opacity: 0.2;
  }
  70% {
    transform: scale(1.04);
    opacity: 1;
  }
  100% {
    transform: scale(1);
    opacity: 1;
  }
}

#to-envelope[hidden],
#cake-cta[hidden] {
  display: none !important;
}

/* Reserve the full opening arc so the heading and controls never move. */
#envelope { gap: 0.9rem; }
#envelope .scene-heading { max-width: 20ch; }
.envelope-stage {
  position: relative;
  display: grid;
  place-items: end center;
  width: min(100%, 380px);
  height: 340px;
  padding-bottom: 20px;
  isolation: isolate;
}
.envelope-glow {
  position: absolute;
  inset: 0 -20px -25px;
  background: radial-gradient(ellipse, rgba(232,143,176,.15), rgba(139,123,216,.1) 42%, transparent 70%);
  pointer-events: none;
}
.envelope-box {
  position: relative;
  width: min(100%, 320px);
  aspect-ratio: 300 / 200;
  isolation: isolate;
  user-select: none;
  filter: drop-shadow(0 20px 24px rgba(0,0,0,.28));
}
.envelope-back-svg, .envelope-front-svg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  display: block;
  pointer-events: none;
}
.envelope-back-svg { z-index: 1; }
.envelope-trigger {
  position: absolute;
  inset: 10% 3.333% 5%;
  z-index: 4;
  border: 0;
  border-radius: 10px;
  background: transparent;
  cursor: pointer;
  -webkit-tap-highlight-color: transparent;
}
.letter-sheet-preview {
  position: absolute;
  left: 11%;
  top: 16%;
  width: 78%;
  height: 76%;
  border: 1px solid #e3d6bf;
  background: linear-gradient(135deg, #fffbef, var(--paper));
  color: var(--paper-ink);
  border-radius: 7px;
  padding: 16px 18px;
  box-shadow: 0 4px 15px rgba(0,0,0,.16);
  z-index: 2;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 10px;
  text-align: left;
  font: inherit;
  transform: translateY(0);
  pointer-events: none;
  transition: transform 550ms cubic-bezier(.22,.68,.24,1);
}
.envelope-box.is-open .letter-sheet-preview {
  transform: translateY(-80%);
  transition-delay: 480ms;
  pointer-events: auto;
  cursor: pointer;
}
.sheet-preview-greeting {
  order: -2;
  font-family: var(--font-display);
  font-style: italic;
  font-size: 1.1rem;
  line-height: 1.2;
  font-weight: 600;
  color: var(--paper-ink);
}

.sheet-preview-line {
  width: 100%;
  height: 6px;
  border-radius: 999px;
  background: rgba(58, 51, 85, 0.18);
}

.sheet-preview-line.short {
  width: 68%;
}

.sheet-preview-cta {
  align-self: flex-start;
  order: -1;
  margin-top: 0;
  font-size: 0.82rem;
  font-weight: 600;
  color: #4A397A;
  background: rgba(139, 123, 216, 0.18);
  padding: 0.3rem 0.75rem;
  border-radius: 999px;
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
}

.sheet-preview-cta .icon {
  width: 0.95rem;
  height: 0.95rem;
  flex: none;
}

.envelope-front-svg {
  z-index: 3;
  pointer-events: none;
}

.envelope-flap {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 60%;
  z-index: 5;
  /* SVG hinge is y=20 in a 120-unit viewBox. */
  transform-origin: 50% 16.6667%;
  transform: perspective(900px) rotateX(0deg);
  transition: transform 550ms cubic-bezier(.4,0,.2,1) 550ms, z-index 0s 825ms;
  pointer-events: none;
}
.envelope-flap > svg { width: 100%; height: 100%; display: block; }
.envelope-box.is-open .envelope-flap {
  transform: perspective(900px) rotateX(-180deg);
  z-index: 1;
  transition: transform 550ms cubic-bezier(.4,0,.2,1), z-index 0s 275ms;
}

.envelope-seal {
  position: absolute;
  left: 50%;
  top: 91%;
  transform: translate(-50%, -50%) scale(1);
  width: 42px;
  height: 42px;
  border-radius: 50%;
  background: radial-gradient(circle at 35% 30%, #F4A8C4, var(--rose) 65%, #B85B80);
  border: 2px solid rgba(255, 243, 196, 0.7);
  box-shadow: 0 4px 14px rgba(0, 0, 0, 0.4);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #ffffff;
  font-size: 1.15rem;
  opacity: 1;
  transition: transform 240ms ease 850ms, opacity 240ms ease 850ms;
}

.envelope-seal svg {
  width: 18px;
  height: 18px;
}

.envelope-box.is-open .envelope-seal {
  transform: translate(-50%, -50%) scale(1.35);
  opacity: 0;
  transition-delay: 0s;
}

.envelope-hint {
  color: var(--ink-soft);
  font-size: 0.92rem;
  max-width: 36ch;
  min-height: 2.9em;
  line-height: 1.45;
}

.envelope-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  justify-content: center;
}

#letter {
  display: block;
  padding: 0;
  text-align: left;
}

.letter-scroll {
  overflow-y: auto;
  max-height: 100dvh;
  min-height: 100dvh;
  -webkit-overflow-scrolling: touch;
  padding: 0 1rem 3.5rem 1rem;
}

.letter-topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: flex-start;
  max-width: 65ch;
  margin: 0 auto;
  padding: 0.85rem 0;
}

#letter-back {
  min-height: 44px;
  padding: 0.55rem 1.2rem;
  font-size: 0.94rem;
  background: rgba(11, 10, 30, 0.65);
  border: 1px solid rgba(201, 194, 232, 0.28);
  backdrop-filter: blur(10px);
}

.letter-container {
  max-width: 65ch;
  margin: 0.25rem auto 0 auto;
  animation: letter-enter 600ms cubic-bezier(0.2, 0.85, 0.3, 1) forwards;
}

@keyframes letter-enter {
  0% {
    transform: translateY(40px);
    opacity: 0;
  }
  100% {
    transform: translateY(0);
    opacity: 1;
  }
}

.letter-torn-edge {
  height: 14px;
  width: 100%;
  background: var(--paper);
  clip-path: polygon(
    0% 100%, 0% 35%, 3% 0%, 6% 45%, 9% 10%, 12% 50%, 15% 5%, 18% 40%, 21% 0%,
    24% 48%, 27% 12%, 30% 45%, 33% 5%, 36% 42%, 39% 8%, 42% 50%, 45% 0%,
    48% 42%, 51% 12%, 54% 46%, 57% 4%, 60% 44%, 63% 10%, 66% 48%, 69% 0%,
    72% 42%, 75% 12%, 78% 45%, 81% 8%, 84% 46%, 87% 4%, 90% 44%, 93% 12%,
    96% 48%, 98% 8%, 100% 40%, 100% 100%
  );
}

#letter-sheet-full {
  background: var(--paper);
  color: var(--paper-ink);
  border-radius: 0 0 8px 8px;
  box-shadow: 0 24px 80px rgba(0, 0, 0, 0.5);
  padding: 2rem 1.5rem 2.25rem 1.5rem;
  max-width: 65ch;
  margin: 0 auto;
  overflow-wrap: anywhere;
}

#letter-sheet-full .greeting {
  font-family: var(--font-display);
  font-style: italic;
  font-size: 1.6rem;
  font-weight: 600;
  color: var(--paper-ink);
  margin-bottom: 1.15rem;
}

#letter-sheet-full .letter-para {
  font-family: var(--font-display);
  font-size: 1.18rem;
  line-height: 1.75;
  color: var(--paper-ink);
  margin-bottom: 1.15rem;
  opacity: 0;
  transform: translateY(12px);
  animation: para-stagger 460ms ease forwards;
}

#letter-sheet-full .letter-para + .letter-para {
  position: relative;
  margin-top: 1.9rem;
  padding-top: 1.6rem;
  border-top: 1px solid rgba(58, 51, 85, 0.16);
}

#letter-sheet-full .letter-para + .letter-para::before {
  content: "✦";
  position: absolute;
  top: -0.72rem;
  left: 50%;
  transform: translateX(-50%);
  background: var(--paper);
  padding: 0 0.6rem;
  color: rgba(58, 51, 85, 0.45);
  font-size: 0.85rem;
}

#letter-sheet-full.has-animated .letter-para {
  opacity: 1;
  transform: none;
  animation: none;
}

@keyframes para-stagger {
  0% {
    opacity: 0;
    transform: translateY(12px);
  }
  100% {
    opacity: 1;
    transform: translateY(0);
  }
}

#letter-sheet-full .closing {
  font-family: var(--font-display);
  font-size: 1.18rem;
  line-height: 1.6;
  color: var(--paper-ink);
  margin-top: 1.75rem;
}

#letter-sheet-full .sign {
  font-family: var(--font-display);
  font-style: italic;
  font-size: 1.45rem;
  font-weight: 600;
  color: var(--paper-ink);
  margin-top: 0.35rem;
}

.letter-footer-actions {
  display: flex;
  justify-content: center;
  margin-top: 1.75rem;
}

@media (prefers-reduced-motion: reduce) {
  .star,
  .firefly,
  .flame,
  .smoke,
  .pop-heading,
  .letter-container,
  #letter-sheet-full .letter-para {
    animation: none !important;
  }

  .star {
    opacity: 0.7;
  }

  .firefly {
    opacity: 0.55;
  }

  .flame {
    opacity: 0.95;
  }

  #letter-sheet-full .letter-para {
    opacity: 1 !important;
    transform: none !important;
  }

  .envelope-flap,
  .envelope-seal,
  .letter-sheet-preview {
    transition-duration: 200ms !important;
  }
}

/* Keep action slots stable across cake and envelope states. */
#cake {
  display: grid;
  grid-template-rows: auto auto 170px;
  align-content: center;
  justify-items: center;
}
#cake > .scene-heading { min-height: 2.4em; display: grid; align-items: center; }
#cake > :is(#cake-cta, #blow-ui, #to-envelope) { grid-row: 3; grid-column: 1; align-self: center; }
#cake-cta { min-width: 160px; }
#to-envelope { max-width: 340px; line-height: 1.45; }
#env-read { visibility: hidden; opacity: 0; transition: opacity 200ms ease; }
#env-read.is-ready { visibility: visible; opacity: 1; }
.envelope-actions { min-height: 110px; align-content: start; width: min(100%, 360px); }
.envelope-actions .btn { padding-inline: 1.35rem; }
button:focus-visible { outline: 3px solid var(--gold); outline-offset: 5px; }
h1:focus, h2:focus { outline: none; }
button:disabled { cursor: default; }
.letter-sheet-preview:focus-visible { outline-offset: 3px; }
.gate-content { width: min(100%, 440px); padding-block: 2.75rem; }
.btn { transition: transform 180ms ease, box-shadow 180ms ease, opacity 180ms ease, background 180ms ease; }
@media (hover: none) { .btn:hover { transform: none; } }
@media (max-width: 360px) {
  .scene { padding-inline: 1rem; }
  .envelope-stage { height: 340px; }
  .sheet-preview-greeting {
  order: -2; font-size: 1.05rem; }
  .sheet-preview-cta { font-size: .72rem; padding-inline: .5rem; }
}
@media (max-height: 650px) and (min-width: 600px) {
  #envelope { padding-top: 1.5rem; }
  .envelope-stage { height: 340px; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; }
  .envelope-flap, .envelope-seal, .letter-sheet-preview { transition: none !important; }
  .btn, #env-read { transition: none; }
  .static-sparkle { animation: none; opacity: .7; }
}