:root {
  --ink: #3d2a22;
  --ink-soft: #71584d;
  --paper: #f8eada;
  --paper-deep: #f3e1ce;
  --line: rgba(250, 236, 224, 0.12);
  --line-strong: rgba(250, 236, 224, 0.2);
  --text: #f8eee4;
  --text-soft: #f2dfd2;
  --muted: #d0b5a8;
  --faint: #ab8f80;
  --accent: #e2a08f;
  --accent-deep: #a8554b;
  --danger: #cf6f66;
  --surface: rgba(250, 236, 224, 0.04);
  --surface-hover: rgba(250, 236, 224, 0.08);
  --panel-surface: linear-gradient(180deg, rgba(76, 45, 49, 0.92), rgba(52, 31, 34, 0.96));
  --shadow: 0 16px 36px rgba(0, 0, 0, 0.5);
  --radius: 22px;
  --transition: 260ms cubic-bezier(0.2, 0.8, 0.2, 1);
}

* {
  box-sizing: border-box;
}

[hidden] {
  display: none !important;
}

html {
  color-scheme: dark;
}

body {
  margin: 0;
  min-height: 100svh;
  font-family: Iowan Old Style, Palatino Linotype, Palatino, Georgia, serif;
  background:
    radial-gradient(circle at 50% 0%, rgba(124, 62, 66, 0.6), rgba(31, 16, 18, 0.98) 56%),
    linear-gradient(180deg, #2b1416 0%, #1a0c0e 100%);
  color: var(--text);
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  background:
    radial-gradient(circle at 22% 10%, rgba(226, 160, 143, 0.1), transparent 34%),
    radial-gradient(circle at 84% 8%, rgba(226, 160, 143, 0.07), transparent 26%),
    linear-gradient(120deg, rgba(255, 228, 214, 0.03), transparent 20%, transparent 80%, rgba(255, 228, 214, 0.03)),
    repeating-linear-gradient(180deg, rgba(255, 228, 214, 0.02) 0 1px, transparent 1px 6px);
  animation: roomBreath 8s ease-in-out infinite;
}

@keyframes roomBreath {
  0%,
  100% {
    opacity: 0.28;
  }
  50% {
    opacity: 0.34;
  }
}

button,
input {
  font: inherit;
}

button {
  appearance: none;
  border: 0;
  background: none;
  color: inherit;
  -webkit-tap-highlight-color: transparent;
}

button:focus-visible,
input:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}

.app-shell {
  position: relative;
  min-height: 100vh;
  min-height: 100svh;
  display: grid;
  place-items: center;
  padding: 20px;
}

.screen {
  width: min(100%, 860px);
}

.screen--lock {
  transition: opacity var(--transition), transform var(--transition);
}

.screen--lock.is-leaving {
  opacity: 0;
  transform: translateY(-6px);
}

.view {
  animation: fadeUp 420ms cubic-bezier(0.2, 0.8, 0.2, 1) both;
}

@keyframes fadeUp {
  from {
    opacity: 0;
    transform: translateY(8px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.view--intro {
  width: min(100%, 520px);
  margin-inline: auto;
}

.view--letter {
  width: min(100%, 600px);
  margin-inline: auto;
}

.panel {
  background: var(--panel-surface);
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
  border-radius: var(--radius);
}

.lock-panel {
  width: min(100%, 460px);
  margin-inline: auto;
  padding: 24px;
}

.intro-panel {
  display: grid;
  gap: 14px;
  padding: 24px;
}

.intro-panel .button {
  justify-self: start;
}

h1,
h2,
.intro-line {
  margin: 0;
  line-height: 1.04;
}

h1 {
  font-size: clamp(2.2rem, 9vw, 3.8rem);
  letter-spacing: -0.03em;
  max-width: 14ch;
  text-wrap: balance;
}

h2 {
  font-size: clamp(1.7rem, 6vw, 2.8rem);
  letter-spacing: -0.025em;
  max-width: 14ch;
}

.intro-line {
  font-size: clamp(2rem, 8vw, 3.2rem);
}

.intro-line--second {
  color: var(--text-soft);
  font-size: clamp(1.1rem, 5vw, 1.6rem);
}

.field-label,
.status,
.chip,
.button {
  font-family: ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

.field-label {
  display: block;
  margin-bottom: 8px;
  color: var(--muted);
  font-size: 0.9rem;
}

.input-row {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 10px;
}

input {
  width: 100%;
  min-width: 0;
  border: 1px solid var(--line-strong);
  border-radius: 14px;
  background: var(--surface);
  color: var(--text);
  padding: 14px 16px;
  transition: border-color var(--transition), background var(--transition);
}

input:hover {
  background: var(--surface-hover);
}

input::placeholder {
  color: var(--faint);
}

.status {
  margin: 0;
  min-height: 1.2em;
  font-size: 0.9rem;
  color: var(--muted);
}

.status[data-tone="error"] {
  color: var(--danger);
}

.chip {
  min-height: 44px;
  padding: 10px 14px;
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  background: var(--surface);
  color: var(--text);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  font-size: 0.92rem;
  transition: border-color var(--transition), background var(--transition);
}

.chip:hover {
  border-color: var(--accent);
}

.chip--music {
  min-width: 84px;
}

.button {
  min-height: 44px;
  padding: 12px 20px;
  border: 1px solid var(--line-strong);
  border-radius: 14px;
  background: var(--surface);
  color: var(--text);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  font-weight: 500;
  cursor: pointer;
  transition: transform var(--transition), border-color var(--transition), background var(--transition), box-shadow var(--transition);
}

.button:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 18px rgba(226, 160, 143, 0.1);
}

.button:active {
  transform: translateY(1px);
}

.button--solid {
  background: rgba(226, 160, 143, 0.16);
  border-color: rgba(226, 160, 143, 0.4);
}

.button--solid:hover {
  box-shadow: 0 6px 18px rgba(226, 160, 143, 0.2);
}

.button--ghost {
  background: transparent;
  border-color: var(--line-strong);
}

.button--ghost:hover {
  border-color: var(--accent);
}

.topbar {
  display: flex;
  justify-content: flex-end;
  align-items: center;
  padding: 4px;
  gap: 10px;
}

.letter-panel {
  width: 100%;
  padding: 32px;
  background: linear-gradient(180deg, var(--paper) 0%, var(--paper-deep) 100%);
  border: 1px solid rgba(110, 70, 60, 0.4);
  border-radius: var(--radius);
  box-shadow: var(--shadow), inset 0 1px 0 rgba(255, 255, 255, 0.5);
  color: var(--ink);
  transition: box-shadow 1.2s ease;
}

.letter-panel::before {
  content: "♡";
  display: block;
  margin-bottom: 26px;
  font-size: 1.4rem;
  line-height: 1;
  color: var(--accent-deep);
  text-align: center;
  opacity: 0.85;
}

.letter-panel :focus-visible {
  outline-color: var(--accent-deep);
}

.letter-stack {
  display: grid;
  gap: 20px;
}

.letter-stack [data-step] {
  display: none;
}

.letter-stack [data-step].is-revealed {
  display: block;
  animation: letterIn 520ms cubic-bezier(0.22, 0.61, 0.36, 1) both;
}

@keyframes letterIn {
  from {
    opacity: 0;
    transform: translateY(12px) scale(0.99);
  }
  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

.letter-stack [data-step].letter-heart.is-revealed {
  animation: heartBeat 3.2s ease-in-out infinite;
}

@keyframes heartBeat {
  0%,
  100% {
    transform: scale(1);
  }
  50% {
    transform: scale(1.07);
  }
}

.letter-secret {
  display: none;
  white-space: pre-line;
}

.letter-secret::first-line {
  font-style: italic;
}

.letter-secret.is-found {
  display: block;
  animation: letterIn 700ms cubic-bezier(0.2, 0.8, 0.2, 1) both;
}

.letter-secret-signoff {
  display: none;
  font-style: italic;
  line-height: 1.7;
  color: var(--ink-soft);
}

.letter-secret-signoff.is-revealed {
  display: grid;
  gap: 6px;
  animation: letterIn 700ms cubic-bezier(0.2, 0.8, 0.2, 1) both;
}

.letter-secret-signoff .letter-kiss {
  color: var(--accent-deep);
  font-size: 1.15rem;
}

body.secret-moment::before {
  animation: secretDim 11s ease-out both;
}

@keyframes secretDim {
  0% {
    opacity: 0.3;
  }
  4% {
    opacity: 0.16;
  }
  8% {
    opacity: 0.3;
  }
  12% {
    opacity: 0.2;
  }
  16% {
    opacity: 0.3;
  }
  30% {
    opacity: 0.14;
  }
  90% {
    opacity: 0.14;
  }
  100% {
    opacity: 0.3;
  }
}

body.secret-moment .letter-panel {
  box-shadow:
    0 0 90px rgba(226, 160, 143, 0.18),
    0 16px 36px rgba(0, 0, 0, 0.5),
    inset 0 1px 0 rgba(255, 255, 255, 0.5);
}

body.bloom::before {
  animation: bloom 900ms ease-out both;
}

@keyframes bloom {
  0% {
    opacity: 0.3;
  }
  45% {
    opacity: 0.5;
  }
  100% {
    opacity: 0.3;
  }
}

.letter-para {
  margin: 0;
  max-width: 42ch;
  font-size: 1.18rem;
  line-height: 1.85;
  color: var(--ink);
  overflow-wrap: break-word;
}

.letter-heart {
  justify-self: start;
  margin: -8px 0;
  padding: 8px;
  background: none;
  color: var(--accent-deep);
  font-size: 2.4rem;
  line-height: 1;
  cursor: pointer;
  touch-action: manipulation;
  user-select: none;
  -webkit-user-select: none;
  -webkit-touch-callout: none;
  transition: color 0.3s ease, text-shadow 0.3s ease;
}

.letter-heart.is-holding {
  animation-play-state: paused;
  color: var(--accent);
  text-shadow: 0 0 26px rgba(226, 160, 143, 0.6);
  transition: color 1.4s linear, text-shadow 1.4s linear;
}

.letter-heart.is-warmed {
  color: var(--accent);
  text-shadow: 0 0 20px rgba(226, 160, 143, 0.45);
}

#intro-hey,
#letter-title {
  touch-action: manipulation;
}

.letter-stack h2 {
  margin: 0;
  color: var(--ink);
  font-size: 1.9rem;
  font-weight: 600;
  letter-spacing: -0.02em;
}

.letter-stack .reveal-step.is-revealed {
  display: grid;
  gap: 16px;
}

.letter-photo {
  display: block;
  width: min(100%, 420px);
  height: auto;
  margin-inline: auto;
  border-radius: 14px;
  border: 1px solid rgba(110, 70, 60, 0.35);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.18);
}

.letter-next-row {
  display: flex;
  margin-top: 28px;
}

.letter-next-row .button {
  background: var(--ink);
  border-color: transparent;
  color: var(--text);
}

.letter-next-row .button:hover {
  border-color: var(--accent-deep);
}

.toast {
  position: fixed;
  left: 50%;
  bottom: 28px;
  transform: translate(-50%, 12px);
  z-index: 50;
  max-width: min(92vw, 460px);
  padding: 12px 18px;
  border-radius: 999px;
  border: 1px solid rgba(226, 160, 143, 0.28);
  background: rgba(30, 17, 19, 0.92);
  color: var(--text);
  font-family: ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: 0.92rem;
  text-align: center;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition), transform var(--transition);
}

.toast.is-visible {
  opacity: 1;
  transform: translate(-50%, 0);
}

@media (min-width: 700px) {
  .letter-panel {
    padding: 38px;
  }
}

@media (max-width: 520px) {
  .app-shell {
    padding: 14px;
  }

  .lock-panel,
  .intro-panel {
    padding: 20px 16px;
  }

  .letter-panel {
    padding: 26px 18px;
  }

  .letter-para {
    font-size: 1.12rem;
  }

  .input-row {
    grid-template-columns: 1fr;
  }
}

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