/* ==========================================================================
   Ember Chat – styles
   Every colour lives here in :root. Change the palette in one minute.
   ========================================================================== */

:root {
  /* Base palette */
  --ink: #0F0E0E;          /* near-black */
  --wine: #541212;         /* deep wine red */
  --teal: #468A9A;         /* candle-flame teal */
  --mist: #EEEEEE;         /* soft paper grey */

  /* Light theme tokens */
  --bg: var(--mist);
  --surface: #F8F6F5;      /* paper, a touch warmer than mist */
  --surface-2: #E4DDDC;    /* folded paper edge */
  --line: #D6CCCB;         /* ruled lines on the paper */
  --text: var(--ink);
  --text-muted: #564B4B;
  --heading: var(--wine);
  --accent: var(--teal);           /* buttons, glow, focus rings */
  --accent-text: #2F6573;          /* teal darkened for text (5.6:1 on --bg) */
  --on-accent: var(--ink);         /* text on teal buttons (4.9:1) */
  --seal: var(--wine);
  --on-seal: var(--mist);
  --bubble-own: var(--wine);
  --on-bubble-own: var(--mist);
  --ember: #B2412E;        /* rising ember sparks */
  --danger: #8E1B1B;
  --shadow-rgb: 84 18 18;  /* wine-tinted shadows */
  --glow-a: var(--teal);
  --glow-b: var(--wine);
  --glow-opacity: 0.22;

  /* Type */
  --font-display: "Merienda", "Segoe Script", cursive;
  --font-body: "Comic Neue", "Comic Sans MS", system-ui, sans-serif;
  --font-label: "Overlock SC", "Trebuchet MS", sans-serif;

  /* Shape */
  --radius-card: 22px 22px 22px 6px;
  --radius-btn: 999px;
  --ease-out: cubic-bezier(0.22, 1, 0.36, 1);

  color-scheme: light;
}

/* Dark theme – same palette, lit by candlelight */
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: var(--ink);
    --surface: #1B1414;
    --surface-2: #2A1C1C;
    --line: #3A2828;
    --text: var(--mist);
    --text-muted: #BDB2B2;
    --heading: var(--mist);
    --accent-text: #7FBCCA;
    --bubble-own: var(--wine);
    --ember: #E0703F;
    --danger: #F08A8A;
    --shadow-rgb: 0 0 0;
    --glow-opacity: 0.30;
    color-scheme: dark;
  }
}

:root[data-theme="dark"] {
  --bg: var(--ink);
  --surface: #1B1414;
  --surface-2: #2A1C1C;
  --line: #3A2828;
  --text: var(--mist);
  --text-muted: #BDB2B2;
  --heading: var(--mist);
  --accent-text: #7FBCCA;
  --bubble-own: var(--wine);
  --ember: #E0703F;
  --danger: #F08A8A;
  --shadow-rgb: 0 0 0;
  --glow-opacity: 0.30;
  color-scheme: dark;
}

/* ---------- Base ---------- */

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

html { scroll-behavior: smooth; }

body {
  margin: 0;
  min-height: 100vh;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-size: 1.0625rem;
  line-height: 1.6;
  overflow-x: hidden;
  transition: background-color 0.4s ease, color 0.4s ease;
}

h1, h2, h3 {
  font-family: var(--font-display);
  color: var(--heading);
  line-height: 1.2;
  margin: 0 0 0.5em;
}

a { color: var(--accent-text); text-underline-offset: 3px; }

img, svg { display: block; }

:focus-visible {
  outline: 3px solid var(--accent);
  outline-offset: 3px;
  border-radius: 6px;
}

.skip-link {
  position: absolute;
  left: 1rem;
  top: -4rem;
  z-index: 100;
  padding: 0.6rem 1rem;
  background: var(--accent);
  color: var(--on-accent);
  font-family: var(--font-label);
  border-radius: var(--radius-btn);
  text-decoration: none;
  transition: transform 0.2s var(--ease-out);
}
.skip-link:focus { transform: translateY(5rem); }

main:focus { outline: none; }

.icon {
  width: 1.25em;
  height: 1.25em;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.8;
  stroke-linecap: round;
  stroke-linejoin: round;
}

/* ---------- Living background: glows + rising embers ---------- */

.backdrop {
  position: fixed;
  inset: 0;
  z-index: -1;
  overflow: hidden;
  pointer-events: none;
}

.glow {
  position: absolute;
  width: 60vmax;
  height: 60vmax;
  border-radius: 50%;
  filter: blur(60px);
  opacity: var(--glow-opacity);
  will-change: transform;
}
.glow--one {
  background: radial-gradient(circle, var(--glow-a), transparent 65%);
  top: -25vmax;
  left: -20vmax;
  animation: drift 26s ease-in-out infinite alternate;
}
.glow--two {
  background: radial-gradient(circle, var(--glow-b), transparent 65%);
  bottom: -30vmax;
  right: -25vmax;
  animation: drift 32s ease-in-out infinite alternate-reverse;
}

@keyframes drift {
  from { transform: translate3d(0, 0, 0) scale(1); }
  to   { transform: translate3d(8vmax, 6vmax, 0) scale(1.15); }
}

.ember {
  position: absolute;
  bottom: -10px;
  width: var(--size, 6px);
  height: var(--size, 6px);
  border-radius: 50%;
  background: var(--ember);
  box-shadow: 0 0 10px 2px var(--ember);
  opacity: 0;
  animation: rise var(--duration, 14s) linear var(--delay, 0s) infinite;
  will-change: transform, opacity;
}

@keyframes rise {
  0%   { transform: translate3d(0, 0, 0) scale(1); opacity: 0; }
  10%  { opacity: 0.8; }
  60%  { opacity: 0.45; }
  100% { transform: translate3d(var(--sway, 30px), -105vh, 0) scale(0.3); opacity: 0; }
}

/* ---------- Header ---------- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.75rem clamp(1rem, 4vw, 2.5rem);
  background: color-mix(in srgb, var(--bg) 78%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid color-mix(in srgb, var(--line) 70%, transparent);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.2rem;
  color: var(--heading);
  text-decoration: none;
}
.brand img { transition: transform 0.6s var(--ease-out); }
.brand:hover img { transform: rotate(-18deg) scale(1.08); }

.header-tools { display: flex; align-items: center; gap: 0.75rem; }

.status-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.3rem 0.8rem;
  border: 1px solid var(--line);
  border-radius: var(--radius-btn);
  background: var(--surface);
  font-family: var(--font-label);
  font-size: 0.85rem;
  color: var(--text-muted);
  white-space: nowrap;
}

.status-dot {
  width: 0.55rem;
  height: 0.55rem;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 0 0 var(--accent);
  animation: pulse 2s ease-out infinite;
}
.status-pill[data-state="demo"] .status-dot { background: var(--ember); }

@keyframes pulse {
  0%   { transform: scale(1); opacity: 1; }
  70%  { transform: scale(1.6); opacity: 0.4; }
  100% { transform: scale(1); opacity: 1; }
}

.theme-toggle {
  display: grid;
  place-items: center;
  width: 2.75rem;
  height: 2.75rem;
  border: 1px solid var(--line);
  border-radius: 50%;
  background: var(--surface);
  color: var(--accent-text);
  cursor: pointer;
  transition: transform 0.25s var(--ease-out), box-shadow 0.25s ease;
}
.theme-toggle:hover { transform: translateY(-2px) rotate(-12deg); box-shadow: 0 8px 18px rgb(var(--shadow-rgb) / 0.18); }
.theme-toggle:active { transform: translateY(1px) scale(0.95); }
.theme-toggle .icon { grid-area: 1 / 1; transition: transform 0.4s var(--ease-out), opacity 0.3s ease; }
.icon--moon { opacity: 0; transform: rotate(-90deg) scale(0.5); }
.is-dark .icon--sun { opacity: 0; transform: rotate(90deg) scale(0.5); }
.is-dark .icon--moon { opacity: 1; transform: none; }

/* ---------- Layout ---------- */

main {
  width: min(100% - 2rem, 62rem);
  margin-inline: auto;
  padding-block: clamp(2rem, 6vw, 4.5rem) 3rem;
}

/* ---------- Hero ---------- */

.hero { text-align: center; margin-bottom: clamp(2.5rem, 6vw, 4rem); }

.kicker {
  display: inline-block;
  margin: 0 0 0.5rem;
  font-family: var(--font-label);
  letter-spacing: 0.12em;
  color: var(--accent-text);
}

.hero h1 {
  font-size: clamp(2.6rem, 9vw, 5rem);
  margin-bottom: 0.3em;
}
.hero h1 span {
  color: var(--accent-text);
  display: inline-block;
  transform: rotate(-4deg);
}

.lead {
  max-width: 34rem;
  margin: 0 auto 2rem;
  color: var(--text-muted);
  font-size: 1.15rem;
}

.stats {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1rem;
  max-width: 40rem;
  margin: 0 auto;
}

.stat {
  padding: 1rem 0.75rem;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-card);
  box-shadow: 0 10px 24px -14px rgb(var(--shadow-rgb) / 0.35);
  transition: transform 0.35s var(--ease-out), box-shadow 0.35s ease;
}
.stat:hover { transform: translateY(-4px) rotate(-1deg); box-shadow: 0 16px 30px -14px rgb(var(--shadow-rgb) / 0.45); }

.stat dt {
  font-family: var(--font-label);
  font-size: 0.85rem;
  color: var(--text-muted);
}
.stat dd {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(1.6rem, 5vw, 2.2rem);
  font-weight: 700;
  color: var(--heading);
}

/* ---------- Chat ---------- */

.chat {
  position: relative;
  padding: clamp(1rem, 3vw, 1.75rem);
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 28px 28px 28px 8px;
  box-shadow: 0 30px 60px -30px rgb(var(--shadow-rgb) / 0.45);
}

/* folded corner, like a letter */
.chat::after {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  width: 2.5rem;
  height: 2.5rem;
  background: linear-gradient(225deg, var(--bg) 50%, var(--surface-2) 50%);
  border-radius: 0 28px 0 12px;
}

.chat-head {
  display: flex;
  flex-wrap: wrap;
  align-items: end;
  justify-content: space-between;
  gap: 0.75rem 1.5rem;
  margin-bottom: 1rem;
  padding-right: 2.5rem;
}
.chat-head h2 { margin: 0; font-size: clamp(1.4rem, 4vw, 1.8rem); }

.field { display: grid; gap: 0.3rem; }
.field label {
  font-family: var(--font-label);
  font-size: 0.9rem;
  color: var(--text-muted);
}
.field input,
.field textarea {
  width: 100%;
  font: inherit;
  color: var(--text);
  background: var(--bg);
  border: 2px solid var(--line);
  border-radius: 14px;
  padding: 0.6rem 0.85rem;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}
.field textarea { resize: vertical; min-height: 3.2rem; max-height: 12rem; }
.field input:hover,
.field textarea:hover { border-color: var(--accent); }
.field input:focus-visible,
.field textarea:focus-visible {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 4px color-mix(in srgb, var(--accent) 30%, transparent);
}
.field--name { min-width: min(14rem, 100%); }

.field-meta {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  margin: 0;
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* lined letter paper */
.paper {
  height: clamp(20rem, 55vh, 30rem);
  overflow-y: auto;
  padding: 1rem clamp(0.5rem, 2vw, 1rem);
  margin-bottom: 1rem;
  border-radius: 18px;
  background-color: var(--bg);
  background-image: repeating-linear-gradient(
    to bottom,
    transparent 0,
    transparent 1.95rem,
    color-mix(in srgb, var(--line) 60%, transparent) 1.95rem,
    color-mix(in srgb, var(--line) 60%, transparent) 2rem
  );
  background-attachment: local;
  border: 1px solid var(--line);
  overscroll-behavior: contain;
}

.letters {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.9rem;
}

.letter {
  display: grid;
  grid-template-columns: 2.6rem minmax(0, 1fr);
  gap: 0.6rem;
  align-items: start;
  max-width: min(34rem, 92%);
  animation: letter-in 0.5s var(--ease-out) both;
}

@keyframes letter-in {
  from { opacity: 0; transform: translateY(14px) scale(0.97); }
  to   { opacity: 1; transform: none; }
}

.letter--own {
  justify-self: end;
  grid-template-columns: minmax(0, 1fr) 2.6rem;
}
.letter--own .seal { order: 2; }

.seal {
  width: 2.6rem;
  height: 2.6rem;
  transition: transform 0.4s var(--ease-out);
}
.seal .seal-wax { fill: var(--seal); }
.seal .seal-ring { fill: none; stroke: var(--on-seal); stroke-opacity: 0.35; stroke-width: 1.5; }
.seal text {
  fill: var(--on-seal);
  font-family: var(--font-label);
}
.letter:hover .seal { transform: rotate(-14deg) scale(1.06); }
.letter--other .seal .seal-wax { fill: var(--teal); }
.letter--other .seal text { fill: var(--ink); }
.letter--other .seal .seal-ring { stroke: var(--ink); }

.bubble {
  padding: 0.55rem 0.9rem 0.6rem;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 4px 18px 18px 18px;
  box-shadow: 0 8px 18px -12px rgb(var(--shadow-rgb) / 0.4);
  transition: transform 0.3s var(--ease-out), box-shadow 0.3s ease;
}
.letter:hover .bubble { transform: translateY(-2px); box-shadow: 0 14px 24px -14px rgb(var(--shadow-rgb) / 0.5); }

.letter--own .bubble {
  background: var(--bubble-own);
  color: var(--on-bubble-own);
  border-color: color-mix(in srgb, var(--teal) 40%, var(--bubble-own));
  border-radius: 18px 4px 18px 18px;
}

.bubble-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 0.75rem;
  font-family: var(--font-label);
  font-size: 0.85rem;
}
.bubble-head strong { font-weight: 400; color: var(--accent-text); }
.bubble-head time { color: var(--text-muted); }
.letter--own .bubble-head strong,
.letter--own .bubble-head time { color: var(--on-bubble-own); opacity: 0.85; }

.bubble p {
  margin: 0.1rem 0 0;
  white-space: pre-wrap;
  overflow-wrap: anywhere;
}

.empty {
  text-align: center;
  color: var(--text-muted);
  font-family: var(--font-display);
  padding: 3rem 1rem;
}

.typing {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin: 0.75rem 0 0;
  font-family: var(--font-label);
  font-size: 0.9rem;
  color: var(--text-muted);
}
.typing[hidden] { display: none; }
.typing-dots { display: inline-flex; gap: 4px; }
.typing-dots i {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent);
  animation: bob 1s ease-in-out infinite;
}
.typing-dots i:nth-child(2) { animation-delay: 0.15s; }
.typing-dots i:nth-child(3) { animation-delay: 0.3s; }

@keyframes bob {
  0%, 100% { transform: translateY(0); opacity: 0.5; }
  50%      { transform: translateY(-5px); opacity: 1; }
}

/* ---------- Composer & buttons ---------- */

.composer {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: start;
  gap: 0.5rem 1rem;
}

.composer-actions {
  display: flex;
  gap: 0.6rem;
  padding-top: 1.55rem;
}

.form-error {
  grid-column: 1 / -1;
  margin: 0;
  min-height: 1.2em;
  color: var(--danger);
  font-size: 0.95rem;
}

.btn {
  position: relative;
  overflow: hidden;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  min-height: 2.9rem;
  padding: 0.6rem 1.3rem;
  border: 2px solid transparent;
  border-radius: var(--radius-btn);
  font-family: var(--font-label);
  font-size: 1rem;
  letter-spacing: 0.04em;
  cursor: pointer;
  transition: transform 0.2s var(--ease-out), box-shadow 0.2s ease, background-color 0.2s ease;
  -webkit-tap-highlight-color: transparent;
}

.btn--primary {
  background: var(--accent);
  color: var(--on-accent);
  box-shadow: 0 6px 0 -1px color-mix(in srgb, var(--accent) 55%, var(--ink)),
              0 12px 22px -8px rgb(var(--shadow-rgb) / 0.45);
}
.btn--primary:hover {
  transform: translateY(-3px);
  box-shadow: 0 9px 0 -1px color-mix(in srgb, var(--accent) 55%, var(--ink)),
              0 18px 28px -10px rgb(var(--shadow-rgb) / 0.5);
}
.btn--primary:active {
  transform: translateY(3px);
  box-shadow: 0 2px 0 -1px color-mix(in srgb, var(--accent) 55%, var(--ink)),
              0 6px 12px -8px rgb(var(--shadow-rgb) / 0.4);
}
.btn[disabled] { cursor: progress; opacity: 0.75; }

.btn--ghost {
  background: transparent;
  color: var(--text);
  border-color: var(--line);
}
.btn--ghost:hover { transform: translateY(-2px); border-color: var(--accent); box-shadow: 0 10px 20px -12px rgb(var(--shadow-rgb) / 0.4); }
.btn--ghost:active { transform: translateY(1px); }

.ripple {
  position: absolute;
  width: 12px;
  height: 12px;
  margin: -6px 0 0 -6px;
  border-radius: 50%;
  background: currentColor;
  opacity: 0.35;
  pointer-events: none;
  animation: ripple 0.6s ease-out forwards;
}
@keyframes ripple {
  to { transform: scale(28); opacity: 0; }
}

/* the envelope flies away when a letter is sent */
.envelope { transition: transform 0.2s ease; }
.btn:hover .envelope { transform: rotate(-8deg); }
.envelope.is-flying { animation: fly 0.7s var(--ease-out); }
@keyframes fly {
  0%   { transform: none; opacity: 1; }
  45%  { transform: translate(38px, -26px) rotate(-20deg) scale(0.7); opacity: 0; }
  46%  { transform: translate(-30px, 10px) scale(0.7); opacity: 0; }
  100% { transform: none; opacity: 1; }
}

/* ---------- Steps ---------- */

.steps { margin-top: clamp(3rem, 8vw, 5rem); }
.steps > h2 { text-align: center; font-size: clamp(1.6rem, 5vw, 2.2rem); }

.step-list {
  list-style: none;
  margin: 1.5rem 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(15rem, 1fr));
  gap: 1.25rem;
}

.step {
  position: relative;
  padding: 1.4rem 1.3rem 1.2rem;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-card);
  box-shadow: 0 14px 30px -20px rgb(var(--shadow-rgb) / 0.45);
  transition: transform 0.35s var(--ease-out), box-shadow 0.35s ease;
}
.step:hover { transform: translateY(-6px) rotate(0.6deg); box-shadow: 0 24px 40px -22px rgb(var(--shadow-rgb) / 0.55); }
.step:nth-child(2):hover { transform: translateY(-6px) rotate(-0.6deg); }

.step-num {
  display: grid;
  place-items: center;
  width: 2.6rem;
  height: 2.6rem;
  margin-bottom: 0.75rem;
  border-radius: 46% 54% 50% 50% / 52% 48% 52% 48%;
  background: var(--seal);
  color: var(--on-seal);
  font-family: var(--font-display);
  font-weight: 700;
  box-shadow: inset 0 0 0 3px color-mix(in srgb, var(--on-seal) 25%, transparent);
}
.step h3 { font-size: 1.3rem; margin-bottom: 0.3rem; }
.step p { margin: 0; color: var(--text-muted); }

/* ---------- Footer ---------- */

.site-footer {
  padding: 2rem 1rem 2.5rem;
  text-align: center;
  font-family: var(--font-label);
  color: var(--text-muted);
}
.site-footer p { margin: 0; }

/* ---------- Reveal on scroll ---------- */

.js .reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.7s var(--ease-out), transform 0.7s var(--ease-out);
}
.js .reveal.is-visible { opacity: 1; transform: none; }

/* ---------- Small screens ---------- */

@media (max-width: 40rem) {
  .status-pill #status-text { max-width: 7.5rem; overflow: hidden; text-overflow: ellipsis; }
  .stats { gap: 0.5rem; }
  .stat { padding: 0.8rem 0.4rem; }
  .stat dt { font-size: 0.75rem; }
  .composer { grid-template-columns: 1fr; }
  .composer-actions { padding-top: 0; }
  .composer-actions .btn { flex: 1 1 0; padding-inline: 0.8rem; }
  .field-meta { flex-direction: column; gap: 0; }
  .field-meta #char-count { align-self: flex-end; }
  .letter { max-width: 100%; }
}

@media (max-width: 26rem) {
  .brand span { display: none; }
}

/* ---------- 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;
  }
  .embers { display: none; }
  .js .reveal { opacity: 1; transform: none; }
}