/* ════════════════════════════════════════════════════════════════
   ROMANCE LETTER · styles.css
   ════════════════════════════════════════════════════════════════
   Sections
     1.  CSS Custom Properties (theme — edit colors here)
     2.  Reset & Base
     3.  Utilities
     4.  Screen System
     5.  Dark Screen Base (landing, closing)
     6.  Light Screen Base (letter)
     7.  Petal Particles
     8.  Screen: Landing
     9.  Screen: Letter
    10.  Screen: Closing
    11.  Buttons
    12.  Keyframe Animations
    13.  Reduced Motion Overrides
    14.  Responsive
════════════════════════════════════════════════════════════════ */


/* ── 1. CSS CUSTOM PROPERTIES ─────────────────────────────────── */
/* Edit these variables to retheme the entire site.               */

:root {
  /* ── Palette ── */
  --color-ink-navy:     #080d18;   /* deepest dark */
  --color-midnight:     #101828;   /* mid dark */
  --color-deep-steel:   #1a2840;   /* lightest dark layer */
  --color-warm-gold:    #c8923a;   /* primary accent — warm lamp glow */
  --color-pale-gold:    #e6c870;   /* lighter gold for glows */
  --color-wine:         #8b2a3a;   /* romantic accent — deep wine red */
  --color-rose:         #a84858;   /* lighter rose for hover states */
  --color-soft-rose:    #c07080;   /* muted rose for subtle accents */
  --color-cream:        #e8dece;   /* warm off-white for dark screens */
  --color-warm-ivory:   #faf6f0;   /* letter paper base */
  --color-parchment:    #f5ede0;   /* letter paper warm tint */
  --color-champagne:    #f0e2c4;   /* heading text on dark */
  --color-silver:       #8a9eb8;   /* muted secondary text on dark */
  --color-charcoal:     #2c2535;   /* letter body text */
  --color-text-dark:    #201c2a;   /* letter heading text */

  /* ── Typography ── */
  --font-serif:         'Playfair Display', Georgia, serif;
  --font-sans:          'Inter', system-ui, -apple-system, sans-serif;
  --font-accent:        'Dancing Script', cursive;

  /* ── Spacing scale ── */
  --sp-2xs:  0.25rem;
  --sp-xs:   0.5rem;
  --sp-sm:   0.875rem;
  --sp-md:   1.25rem;
  --sp-lg:   2rem;
  --sp-xl:   3rem;
  --sp-2xl:  4.5rem;

  /* ── Radii ── */
  --radius-sm:  8px;
  --radius-md:  14px;
  --radius-lg:  18px;

  /* ── Transitions ── */
  --ease-out-expo:  cubic-bezier(0.16, 1, 0.3, 1);
  --ease-spring:    cubic-bezier(0.34, 1.56, 0.64, 1);
  --t-fast:  0.18s ease;
  --t-med:   0.45s ease;
  --t-slow:  0.85s var(--ease-out-expo);
  --t-screen: 650ms var(--ease-out-expo);
}


/* ── 2. RESET & BASE ───────────────────────────────────────────── */

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

html {
  font-size: 16px;
  height: 100%;                  /* iOS viewport fix */
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  background: var(--color-ink-navy);
  color: var(--color-cream);
  line-height: 1.6;
  overflow: hidden;
  overscroll-behavior: none;     /* prevent pull-to-refresh / rubber-band on iOS */
  min-height: 100dvh;
  min-height: 100vh;
}

button {
  cursor: pointer;
  border: none;
  background: none;
  font-family: inherit;
  -webkit-tap-highlight-color: transparent;
}

input[type="number"] {
  appearance: textfield;
  -moz-appearance: textfield;
}

input[type="number"]::-webkit-outer-spin-button,
input[type="number"]::-webkit-inner-spin-button {
  -webkit-appearance: none;
  margin: 0;
}

/* ── 3. UTILITIES ─────────────────────────────────────────────── */

.sr-only {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.fade-up {
  animation: fadeUp 1s var(--ease-out-expo) both;
}


/* ── 4. SCREEN SYSTEM ─────────────────────────────────────────── */

.screen {
  position: fixed;
  inset: 0;
  z-index: 10;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;

  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transition: opacity var(--t-screen), visibility var(--t-screen);
}

.screen.active {
  opacity: 1;
  visibility: visible;
  pointer-events: all;
  z-index: 20;
}

.screen.exiting {
  opacity: 0;
  z-index: 15;
  pointer-events: none;
  transition: opacity 580ms ease;
}


/* ── 5. DARK SCREEN BASE ─────────────────────────────────────── */
/* Deep midnight navy — like a room lit only by a desk lamp       */

.screen--dark {
  background:
    radial-gradient(ellipse 55% 45% at 50% 15%,
      rgba(200, 146, 58, 0.07) 0%,
      transparent 55%),
    linear-gradient(170deg,
      var(--color-ink-navy)  0%,
      var(--color-midnight)  50%,
      #07101e               100%);
}

/* Warm single-source glow from above — like a lamp */
.ambient-glow {
  position: absolute;
  inset: 0;
  background: radial-gradient(
    ellipse 50% 40% at 50% 0%,
    rgba(200, 146, 58, 0.09) 0%,
    transparent 60%
  );
  pointer-events: none;
  z-index: 1;
}

.ambient-glow--subtle { opacity: 0.6; }


/* ── LETTER SCREEN BASE ───────────────────────────────────────── */
/* Same dark navy as landing/closing — unified look              */

.screen--light {
  background:
    radial-gradient(ellipse 55% 45% at 50% 15%,
      rgba(200, 146, 58, 0.07) 0%,
      transparent 55%),
    linear-gradient(170deg,
      var(--color-ink-navy)  0%,
      var(--color-midnight)  50%,
      #07101e               100%);
  justify-content: flex-start;
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
  overscroll-behavior-y: contain;  /* contain scroll — no bleed to parent on iOS */
}


/* ── 7. PETAL PARTICLES ──────────────────────────────────────── */
/* Warm golden particles — like dust in lamplight                 */

.petals {
  position: absolute;
  inset: 0;
  overflow: hidden;
  pointer-events: none;
  z-index: 2;
}

.petal {
  position: absolute;
  top: -6%;
  border-radius: 50% 50% 50% 50% / 60% 60% 40% 40%;
  opacity: 0;
  animation: petalDrift linear infinite;
  will-change: transform, opacity;
  background: rgba(200, 146, 58, 0.22);  /* warm gold */
}

.petals--light .petal {
  background: rgba(200, 146, 58, 0.22);  /* same gold as dark screens */
}


/* ── 8. SCREEN: LANDING ──────────────────────────────────────── */

/* ── Birthday gate ───────────────────────────────────────────── */

.birthday-card {
  position: relative;
  z-index: 5;
  width: min(100%, 500px);
  margin: 0 var(--sp-md);
  padding: clamp(var(--sp-lg), 7vw, 2.5rem);
  padding-top: max(clamp(var(--sp-lg), 7vw, 2.5rem), env(safe-area-inset-top, 0px));
  padding-bottom: max(clamp(var(--sp-lg), 7vw, 2.5rem), env(safe-area-inset-bottom, 0px));
  padding-left: max(var(--sp-md), env(safe-area-inset-left, 0px));
  padding-right: max(var(--sp-md), env(safe-area-inset-right, 0px));
  text-align: center;
  background: rgba(16, 26, 44, 0.82);
  border: 1px solid rgba(200, 146, 58, 0.18);
  border-top: 2px solid rgba(200, 146, 58, 0.36);
  border-radius: var(--radius-lg);
  box-shadow:
    0 12px 70px rgba(0, 0, 0, 0.40),
    0 1px 0 rgba(200, 146, 58, 0.08) inset,
    0 0 0 1px rgba(200, 146, 58, 0.05) inset;
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}

.birthday-prompt {
  font-family: var(--font-accent);
  font-size: 1.05rem;
  color: var(--color-warm-gold);
  margin-bottom: var(--sp-xs);
  opacity: 0.85;
}

.birthday-question {
  font-family: var(--font-serif);
  font-size: clamp(1.35rem, 5vw, 2rem);
  font-weight: 600;
  line-height: 1.2;
  color: var(--color-champagne);
  margin-bottom: var(--sp-lg);
}

.birthday-fieldset {
  border: 0;
}

.birthday-inputs {
  display: flex;
  align-items: flex-end;
  justify-content: center;
  gap: 0.55rem;
  margin-bottom: var(--sp-md);
}

.input-group {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.45rem;
}

.input-group label {
  font-size: 0.72rem;
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-silver);
}

.input-group input {
  width: 3.8rem;
  min-height: 50px;
  padding: 0.65rem 0.4rem;
  border-radius: var(--radius-sm);
  border: 1px solid rgba(200, 146, 58, 0.22);
  background: rgba(8, 13, 24, 0.55);
  color: var(--color-champagne);
  font-family: var(--font-serif);
  font-size: 1.15rem;
  text-align: center;
  outline: none;
  transition: border-color var(--t-fast), box-shadow var(--t-fast), background var(--t-fast);
}

.input-group input::placeholder {
  color: rgba(138, 158, 184, 0.5);
}

.input-group input:focus {
  border-color: rgba(200, 146, 58, 0.55);
  background: rgba(8, 13, 24, 0.75);
  box-shadow: 0 0 0 3px rgba(200, 146, 58, 0.12);
}

.input-group--wide input {
  width: 5.5rem;
}

.input-sep {
  align-self: center;
  padding-bottom: 0.25rem;
  color: rgba(200, 146, 58, 0.65);
  font-family: var(--font-serif);
  font-size: 1.35rem;
}

.birthday-error {
  min-height: 1.5rem;
  margin-bottom: var(--sp-sm);
  color: #e8a5b0;
  font-size: 0.92rem;
}

.birthday-form.shake {
  animation: gateShake 0.45s ease;
}

.landing-content {
  position: relative;
  z-index: 5;
  text-align: center;
  padding: var(--sp-lg) var(--sp-md);
  /* safe area: push content away from notch / home bar */
  padding-top:    max(var(--sp-lg),  env(safe-area-inset-top,    0px));
  padding-bottom: max(var(--sp-lg),  env(safe-area-inset-bottom, 0px));
  padding-left:   max(var(--sp-md),  env(safe-area-inset-left,   0px));
  padding-right:  max(var(--sp-md),  env(safe-area-inset-right,  0px));
  max-width: 500px;
  width: 100%;
}

/* The ✦ accent — gold star, restrained */
.accent-mark {
  display: block;
  font-family: var(--font-accent);
  font-size: 1.3rem;
  color: var(--color-warm-gold);
  margin-bottom: var(--sp-md);
  opacity: 0.7;
  animation: pulseGlow 5s ease-in-out infinite;
}

.landing-title {
  font-family: var(--font-serif);
  font-size: clamp(2.8rem, 11vw, 5.2rem);
  font-weight: 600;                        /* bolder — more confident */
  color: var(--color-champagne);
  letter-spacing: 0.01em;
  line-height: 1.05;
  margin-bottom: var(--sp-md);
  text-shadow:
    0 0 70px rgba(200, 146, 58, 0.20),
    0 3px 18px rgba(0, 0, 0, 0.55);
}

.landing-subtitle {
  font-family: var(--font-sans);
  font-size: clamp(0.85rem, 3vw, 1rem);
  font-weight: 300;
  color: var(--color-silver);
  letter-spacing: 0.06em;
  margin-bottom: var(--sp-xl);
  opacity: 0.9;
}


/* ── 9. SCREEN: LETTER ──────────────────────────────────────── */

.letter-scroll-area {
  width: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: clamp(var(--sp-lg), 6vw, var(--sp-2xl)) var(--sp-md);
  /* safe area insets for notched phones */
  padding-top:    max(clamp(var(--sp-lg), 6vw, var(--sp-2xl)), env(safe-area-inset-top,    0px));
  padding-bottom: max(var(--sp-2xl),                           env(safe-area-inset-bottom, 0px));
  padding-left:   max(var(--sp-md),                            env(safe-area-inset-left,   0px));
  padding-right:  max(var(--sp-md),                            env(safe-area-inset-right,  0px));
  min-height: 100%;
}

/* ── Letter card — dark glass on dark background ── */
.letter-card {
  position: relative;
  z-index: 5;
  background: rgba(16, 26, 44, 0.82);
  border: 1px solid rgba(200, 146, 58, 0.20);
  border-top: 2px solid rgba(200, 146, 58, 0.40);
  border-radius: var(--radius-lg);
  padding: clamp(var(--sp-lg), 7vw, var(--sp-2xl)) clamp(var(--sp-md), 6vw, var(--sp-xl));
  max-width: 660px;
  width: 100%;
  box-shadow:
    0 12px 70px rgba(0, 0, 0, 0.45),
    0 1px 0 rgba(200, 146, 58, 0.08) inset,
    0 0 0 1px rgba(200, 146, 58, 0.06) inset;
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);

  animation: cardAppear 1.1s var(--ease-out-expo) both;
}

/* Subtle gold corner tints */
.letter-card::before {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: inherit;
  background:
    linear-gradient(130deg, rgba(200, 146, 58, 0.06) 0%, transparent 35%),
    linear-gradient(310deg, rgba(200, 146, 58, 0.04) 0%, transparent 35%);
  pointer-events: none;
}

/* Shimmer sweep on reveal */
.letter-card::after {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0; bottom: 0;
  border-radius: inherit;
  background: linear-gradient(
    115deg,
    transparent 20%,
    rgba(200, 146, 58, 0.15) 50%,
    transparent 80%
  );
  pointer-events: none;
  opacity: 0;
  animation: shimmerOnce 2s 0.3s ease forwards;
}

/* ── Letter header ── */
.letter-header {
  text-align: center;
  margin-bottom: var(--sp-lg);
}

.letter-deco {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--sp-md);
  margin-bottom: var(--sp-md);
}

.deco-line {
  flex: 1;
  max-width: 90px;
  height: 1px;
  background: linear-gradient(90deg,
    transparent 0%,
    rgba(200, 146, 58, 0.50) 50%,
    transparent 100%);
}

.deco-bloom {
  color: var(--color-warm-gold);
  font-size: 1rem;
  opacity: 0.60;
}

.letter-title {
  font-family: var(--font-serif);
  font-size: clamp(1.35rem, 5vw, 2rem);
  font-weight: 600;
  color: var(--color-champagne);
  letter-spacing: 0.01em;
  margin-bottom: var(--sp-sm);
}

.letter-salutation {
  font-family: var(--font-serif);
  font-style: italic;
  font-size: clamp(0.95rem, 2.8vw, 1.1rem);
  color: var(--color-warm-gold);
  opacity: 0.88;
}

/* ── Letter body ── */
.letter-body {
  margin-bottom: var(--sp-xl);
}

.letter-paragraph {
  font-family: var(--font-serif);
  font-size: clamp(0.975rem, 2.6vw, 1.05rem);
  line-height: 1.95;
  color: var(--color-cream);
  margin-bottom: 1.65em;

  opacity: 0;
  transform: translateY(14px);
  transition: opacity 0.9s ease, transform 0.9s ease;
}

.letter-paragraph.revealed {
  opacity: 1;
  transform: translateY(0);
}

.letter-paragraph:last-child {
  margin-bottom: 0;
}

/* ── Letter footer ── */
.letter-footer {
  text-align: center;
  padding-top: var(--sp-md);
}

.letter-footer .letter-deco {
  margin-bottom: var(--sp-md);
}

.letter-signature {
  font-family: var(--font-accent);
  font-size: 1.65rem;
  color: var(--color-pale-gold);
  opacity: 0.85;
  line-height: 1.2;
}

/* ── Continue button ── */
.letter-continue {
  margin-top: var(--sp-lg);
  text-align: center;
  opacity: 0;
  transform: translateY(10px);
  transition: opacity 1.1s ease, transform 1.1s ease;
  pointer-events: none;
}

.letter-continue.visible {
  opacity: 1;
  transform: translateY(0);
  pointer-events: all;
}

.letter-end-spacer {
  height: 3rem;
}

/* ── Easter egg: lily corner blooms ── */
.lily-corner {
  position: fixed;
  width: 80px;
  height: 80px;
  pointer-events: none;
  z-index: 6;
  opacity: 0;
  transform: scale(0.5);
  transition:
    opacity 1.1s ease,
    transform 1.2s var(--ease-spring);
}

.lily-corner.bloomed          { opacity: 1; transform: scale(1); }

.lily-corner--tl { top: 0; left: 0; transform-origin: top left; }
.lily-corner--tr { top: 0; right: 0; transform-origin: top right;
  transform: scale(0.5) rotate(90deg); }
.lily-corner--bl { bottom: 0; left: 0; transform-origin: bottom left;
  transform: scale(0.5) rotate(-90deg); }
.lily-corner--br { bottom: 0; right: 0; transform-origin: bottom right;
  transform: scale(0.5) rotate(180deg); }

.lily-corner--tr.bloomed { transform: scale(1) rotate(90deg); }
.lily-corner--bl.bloomed { transform: scale(1) rotate(-90deg); }
.lily-corner--br.bloomed { transform: scale(1) rotate(180deg); }


/* ── 10. SCREEN: CLOSING ─────────────────────────────────────── */

.closing-content {
  position: relative;
  z-index: 5;
  text-align: center;
  padding: var(--sp-lg) var(--sp-md);
  padding-bottom: max(var(--sp-lg), env(safe-area-inset-bottom, 0px));
  padding-left:   max(var(--sp-md), env(safe-area-inset-left,   0px));
  padding-right:  max(var(--sp-md), env(safe-area-inset-right,  0px));
  max-width: 380px;
}

.closing-note {
  font-family: var(--font-serif);
  font-style: italic;
  font-size: clamp(1.1rem, 4vw, 1.4rem);
  color: var(--color-cream);
  margin-bottom: var(--sp-xl);
  line-height: 1.6;
  opacity: 0.85;
}


/* ── 11. BUTTONS ─────────────────────────────────────────────── */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.9rem 2.4rem;
  min-height: 44px;              /* WCAG / Apple HIG minimum touch target */
  border-radius: 6px;
  font-family: var(--font-sans);
  font-size: 0.82rem;
  font-weight: 500;
  letter-spacing: 0.10em;
  text-transform: uppercase;
  text-decoration: none;
  user-select: none;
  touch-action: manipulation;    /* removes 300ms tap delay on older mobile browsers */
  transition:
    background var(--t-fast),
    transform var(--t-fast),
    box-shadow var(--t-fast),
    border-color var(--t-fast),
    color var(--t-fast);
}

.btn:focus-visible {
  outline: 2px solid var(--color-warm-gold);
  outline-offset: 3px;
}

/* Primary — deep wine red, intentional */
.btn--primary {
  background: linear-gradient(145deg,
    var(--color-wine) 0%,
    #6e2030 100%);
  color: #f5ece8;
  box-shadow:
    0 4px 24px rgba(139, 42, 58, 0.38),
    0 1px 0 rgba(255, 255, 255, 0.10) inset;
}

.btn--primary:hover {
  background: linear-gradient(145deg, var(--color-rose) 0%, #8b2a3a 100%);
  transform: translateY(-2px);
  box-shadow:
    0 8px 32px rgba(139, 42, 58, 0.48),
    0 1px 0 rgba(255, 255, 255, 0.10) inset;
}

.btn--primary:active {
  transform: translateY(0);
  box-shadow: 0 2px 12px rgba(139, 42, 58, 0.30);
}

/* Ghost — thin gold border on dark, wine on light */
.btn--ghost {
  background: transparent;
  border: 1px solid rgba(200, 146, 58, 0.30);
  color: var(--color-warm-gold);
  border-radius: 6px;
}

.btn--ghost:hover {
  background: rgba(200, 146, 58, 0.07);
  border-color: rgba(200, 146, 58, 0.55);
  transform: translateY(-1px);
}

.btn--ghost:active {
  transform: translateY(0);
}


/* Optional audio toggle */
.btn-audio {
  position: fixed;
  bottom: 1.1rem;
  right: 1.1rem;
  z-index: 100;
  width: 44px;
  height: 44px;
  border-radius: 6px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(200, 146, 58, 0.18);
  color: var(--color-warm-gold);
  font-size: 1.05rem;
  display: flex;
  align-items: center;
  justify-content: center;
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  transition: background var(--t-fast), transform var(--t-fast);
}

.btn-audio:hover {
  background: rgba(200, 146, 58, 0.10);
  transform: scale(1.06);
}


/* ── 12. KEYFRAME ANIMATIONS ─────────────────────────────────── */

@keyframes fadeUp {
  from { opacity: 0; transform: translateY(24px); }
  to   { opacity: 1; transform: translateY(0); }
}

@keyframes petalDrift {
  0% {
    opacity: 0;
    transform: translateX(0) translateY(-6vh) rotate(0deg);
  }
  6%  { opacity: var(--petal-opacity, 0.32); }
  93% { opacity: var(--petal-opacity, 0.32); }
  100% {
    opacity: 0;
    transform:
      translateX(var(--drift, 55px))
      translateY(108vh)
      rotate(var(--spin, 300deg));
  }
}

@keyframes pulseGlow {
  0%, 100% { opacity: 0.50; text-shadow: none; }
  50%       { opacity: 0.85; text-shadow: 0 0 16px rgba(200, 146, 58, 0.55); }
}

@keyframes cardAppear {
  from { opacity: 0; transform: translateY(20px) scale(0.988); }
  to   { opacity: 1; transform: translateY(0)    scale(1); }
}

@keyframes shimmerOnce {
  0%   { opacity: 0; transform: translateX(-110%); }
  30%  { opacity: 1; }
  100% { opacity: 0; transform: translateX(110%); }
}

@keyframes gateShake {
  0%, 100% { transform: translateX(0); }
  20% { transform: translateX(-8px); }
  40% { transform: translateX(7px); }
  60% { transform: translateX(-5px); }
  80% { transform: translateX(4px); }
}


/* ── 13. REDUCED MOTION ──────────────────────────────────────── */

@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;
  }

  .petal { display: none; }

  .letter-paragraph {
    opacity: 1 !important;
    transform: none !important;
  }

  .letter-continue {
    opacity: 1 !important;
    transform: none !important;
    pointer-events: all !important;
  }

  .lily-corner.bloomed { opacity: 0.6 !important; }
}


/* ── 14. RESPONSIVE ──────────────────────────────────────────── */

/* ── Touch devices: disable hover lift (prevents stuck states) ── */
@media (hover: none) {
  .btn--primary:hover,
  .btn--ghost:hover {
    transform: none;
  }
}

/* ── Backdrop-filter fallback (older Android / Firefox < 103) ── */
@supports not ((-webkit-backdrop-filter: blur(1px)) or (backdrop-filter: blur(1px))) {
  .letter-card {
    background: rgba(10, 18, 32, 0.97);
  }
}

/* ── Small phones  (≤ 430px — iPhone SE, Galaxy A series, etc.) ── */
@media (max-width: 430px) {
  .birthday-card {
    border-radius: var(--radius-md);
    padding-top: max(var(--sp-lg), env(safe-area-inset-top, 0px));
    padding-bottom: max(var(--sp-lg), env(safe-area-inset-bottom, 0px));
  }

  .birthday-inputs {
    gap: 0.35rem;
  }

  .input-group input {
    width: 3.25rem;
    min-height: 46px;
    font-size: 1rem;
  }

  .input-group--wide input {
    width: 4.8rem;
  }

  .birthday-question {
    font-size: clamp(1.2rem, 6vw, 1.55rem);
  }

  .letter-card {
    border-radius: var(--radius-md);
    padding: var(--sp-md) var(--sp-sm);
  }

  .letter-signature {
    font-size: 1.35rem;
  }

  .btn {
    padding: 0.85rem 1.6rem;
    letter-spacing: 0.08em;
  }

  .lily-corner {
    width: 52px;
    height: 52px;
  }

  /* Tighten paragraph spacing on small screens */
  .letter-paragraph {
    line-height: 1.85;
    margin-bottom: 1.4em;
  }
}

/* ── Tablet / large phone  (≥ 600px) ── */
@media (min-width: 600px) {
  .lily-corner { width: 110px; height: 110px; }

  .letter-scroll-area {
    padding-top:    max(3rem, env(safe-area-inset-top,    0px));
    padding-bottom: max(3rem, env(safe-area-inset-bottom, 0px));
  }
}

/* ── Desktop  (≥ 900px) ── */
@media (min-width: 900px) {

  .letter-card {
    padding: 3.5rem;
  }
}