/* ═══════════════════════════════════════════════════════════════
   LITU AI Co-Creator · Design System
   Luxury / fashion-editorial · gold · crimson · ink · bone
   Locked palette · Fraunces + Space Grotesk + JetBrains Mono
   ═══════════════════════════════════════════════════════════════ */

@layer reset, tokens, base, components, utilities;

@layer reset {
  *,*::before,*::after { box-sizing: border-box; margin: 0; padding: 0; }
  html { -webkit-text-size-adjust: 100%; text-size-adjust: 100%; scroll-behavior: smooth; }
  body { line-height: 1.5; -webkit-font-smoothing: antialiased; }
  img,svg,video { display: block; max-width: 100%; }
  button,input,textarea,select { font: inherit; color: inherit; }
  button { background: none; border: none; cursor: pointer; }
  a { color: inherit; text-decoration: none; }
  ul,ol { list-style: none; }
  :focus { outline: none; }
  :focus-visible {
    outline: 2px solid var(--gold);
    outline-offset: 3px;
    border-radius: 2px;
  }
  ::selection { background: var(--gold); color: var(--ink); }
}

@layer tokens {
  :root {
    /* Locked palette */
    --ink:        #000000;        /* pitch black — body, headings, primary text */
    --ink-soft:   #1A1614;        /* near-black — de-emphasised but still legible */
    --ink-faint:  #4A4640;        /* darkened — meta lines and labels no longer pale */
    --bone:       #FAF7F0;
    --bone-warm:  #F4EFE6;
    --bone-deep:  #ECE5D5;
    --gold:       #B8860B;
    --gold-soft:  #DDB967;
    --gold-glow:  rgba(184,134,11,.18);
    --crimson:    #9B1C2E;
    --crimson-deep: #6B0F1B;
    --crimson-soft: rgba(155,28,46,.10);
    --hairline:   rgba(12,10,9,.10);
    --hairline-strong: rgba(12,10,9,.20);

    /* Type */
    --font-display: 'Fraunces', 'Playfair Display', Georgia, serif;
    --font-ui:      'Space Grotesk', system-ui, -apple-system, sans-serif;
    --font-mono:    'JetBrains Mono', ui-monospace, 'SF Mono', Menlo, monospace;

    /* Type scale (clamped, fluid) */
    --fs-xs:  clamp(0.69rem, 0.66rem + 0.10vw, 0.75rem);   /* 11–12 */
    --fs-sm:  clamp(0.78rem, 0.74rem + 0.18vw, 0.875rem);  /* 12.5–14 */
    --fs-base: clamp(0.95rem, 0.92rem + 0.18vw, 1.0625rem); /* 15–17 */
    --fs-md:  clamp(1.0625rem, 1.00rem + 0.30vw, 1.1875rem); /* 17–19 */
    --fs-lg:  clamp(1.25rem, 1.10rem + 0.60vw, 1.5rem);    /* 20–24 */
    --fs-xl:  clamp(1.625rem, 1.40rem + 1.00vw, 2.25rem);  /* 26–36 */
    --fs-2xl: clamp(2.25rem, 1.80rem + 2.20vw, 3.5rem);    /* 36–56 */
    --fs-3xl: clamp(3rem, 2.25rem + 3.50vw, 5.25rem);      /* 48–84 */
    --fs-4xl: clamp(3.75rem, 2.50rem + 6.00vw, 7.5rem);    /* 60–120 */

    /* Spacing scale (8-pt baseline) */
    --s-1:  4px;  --s-2:  8px;  --s-3: 12px; --s-4: 16px;
    --s-5: 20px;  --s-6: 24px;  --s-7: 32px; --s-8: 40px;
    --s-9: 56px;  --s-10: 72px; --s-11: 96px; --s-12: 128px; --s-13: 160px;

    /* Radii */
    --r-sm: 4px;  --r: 8px; --r-md: 12px; --r-lg: 16px; --r-xl: 24px; --r-pill: 999px;

    /* Motion */
    --ease-out: cubic-bezier(.2,.8,.2,1);
    --ease-spring: cubic-bezier(.34,1.56,.64,1);
    --t-fast: 150ms;
    --t: 250ms;
    --t-slow: 600ms;

    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(12,10,9,.06);
    --shadow:    0 8px 24px rgba(12,10,9,.08), 0 1px 2px rgba(12,10,9,.04);
    --shadow-lg: 0 24px 56px rgba(12,10,9,.14), 0 2px 4px rgba(12,10,9,.04);

    /* Layout */
    --container: 1240px;
    --container-narrow: 880px;
  }

  @media (prefers-reduced-motion: reduce) {
    *,*::before,*::after {
      animation-duration: .01ms !important;
      animation-iteration-count: 1 !important;
      transition-duration: .01ms !important;
      scroll-behavior: auto !important;
    }
  }
}

@layer base {
  /* Bump base by 15% for readability — scales the entire rem-based type system */
  html { font-size: 115%; }

  body {
    font-family: var(--font-ui);
    font-size: var(--fs-base);
    color: var(--ink);
    background: #ffffff;
    font-feature-settings: "ss01","cv11";
    text-rendering: optimizeLegibility;
  }

  h1,h2,h3,h4 {
    font-family: var(--font-display);
    font-weight: 500;
    letter-spacing: -0.02em;
    line-height: 1.05;
    color: var(--ink);
    font-variation-settings: "opsz" 144, "SOFT" 30;
    text-wrap: balance;
  }
  h1 { font-size: var(--fs-4xl); font-weight: 400; letter-spacing: -0.035em; }
  h2 { font-size: var(--fs-3xl); font-weight: 400; letter-spacing: -0.03em; }
  h3 { font-size: var(--fs-xl); font-weight: 500; line-height: 1.15; }
  h4 { font-size: var(--fs-lg); font-weight: 500; line-height: 1.2; }

  p { color: var(--ink); font-size: var(--fs-base); line-height: 1.65; text-wrap: pretty; }

  a { transition: color var(--t-fast) var(--ease-out); }
  a:hover { color: var(--crimson); }

  ::placeholder { color: var(--ink-faint); opacity: 1; }

  /* Heading accent utilities — black + gold + crimson combination */
  .accent-gold,
  h1 em.accent-gold, h2 em.accent-gold, h3 em.accent-gold, h4 em.accent-gold { color: var(--gold); }
  .accent-crimson,
  h1 em.accent-crimson, h2 em.accent-crimson, h3 em.accent-crimson, h4 em.accent-crimson { color: var(--crimson); }
  .accent-crimson-deep { color: var(--crimson-deep); }
  /* Italic em inside display headings — by default keep them inheritable; pages opt-in to colour with the classes above */
}

@layer components {

  /* Skip link */
  .skip-link {
    position: absolute; top: -100px; left: 16px;
    background: var(--ink); color: var(--bone);
    padding: 12px 18px; border-radius: var(--r-sm);
    font-family: var(--font-ui); font-size: var(--fs-sm); font-weight: 500;
    z-index: 999; transition: top var(--t) var(--ease-out);
  }
  .skip-link:focus-visible { top: 16px; color: var(--bone); }

  /* Container */
  .container { width: 100%; max-width: var(--container); margin: 0 auto; padding: 0 clamp(20px, 4vw, 48px); }
  .container-narrow { max-width: var(--container-narrow); }

  /* Eyebrows + meta */
  .eyebrow {
    font-family: var(--font-ui);
    font-size: var(--fs-xs);
    font-weight: 500;
    letter-spacing: 0.22em;
    text-transform: uppercase;
    color: var(--ink-faint);
    display: inline-flex; align-items: center; gap: 10px;
  }
  .eyebrow::before {
    content: ""; width: 18px; height: 1px; background: var(--gold);
  }
  .eyebrow-gold { color: var(--gold); }
  .eyebrow-gold::before { background: var(--gold); }

  .meta-mono {
    font-family: var(--font-mono);
    font-size: var(--fs-xs);
    font-feature-settings: "tnum","ss01";
    color: var(--ink-faint);
    letter-spacing: 0.06em;
  }

  /* Lede / lead paragraph */
  .lede {
    font-size: var(--fs-md);
    color: var(--ink-soft);
    line-height: 1.55;
    max-width: 60ch;
  }

  /* Buttons */
  .btn {
    display: inline-flex; align-items: center; justify-content: center; gap: 10px;
    padding: 14px 26px;
    font-family: var(--font-ui); font-size: var(--fs-sm); font-weight: 500;
    letter-spacing: 0.04em;
    border-radius: var(--r-pill);
    transition: background var(--t) var(--ease-out),
                color var(--t) var(--ease-out),
                transform var(--t) var(--ease-out),
                box-shadow var(--t) var(--ease-out),
                border-color var(--t) var(--ease-out);
    will-change: transform;
    text-decoration: none;
    border: 1px solid transparent;
  }
  .btn:hover { transform: translateY(-1px); }
  .btn:active { transform: translateY(0); }
  .btn[disabled],.btn[aria-disabled="true"] {
    opacity: 0.5; cursor: not-allowed; pointer-events: none;
  }
  .btn-primary {
    background: var(--ink); color: var(--bone);
  }
  .btn-primary:hover { background: var(--crimson); color: var(--bone); }
  .btn-gold {
    background: var(--gold); color: var(--ink);
  }
  .btn-gold:hover { background: var(--gold-soft); color: var(--ink); box-shadow: 0 12px 32px var(--gold-glow); }
  .btn-ghost {
    background: transparent; color: var(--ink); border-color: var(--hairline-strong);
  }
  .btn-ghost:hover { border-color: var(--ink); color: var(--ink); }
  .btn-arrow {
    display: inline-flex; align-items: center; gap: 6px;
    font-family: var(--font-ui); font-size: var(--fs-sm); font-weight: 500;
    color: var(--ink); border-bottom: 1px solid transparent;
    padding-bottom: 2px; transition: border-color var(--t) var(--ease-out), color var(--t) var(--ease-out);
  }
  .btn-arrow:hover { border-color: var(--gold); color: var(--ink); }
  .btn-arrow svg { transition: transform var(--t) var(--ease-out); }
  .btn-arrow:hover svg { transform: translateX(3px); }

  /* Input — luxury feel */
  .field { display: flex; flex-direction: column; gap: 6px; }
  .field-label {
    font-family: var(--font-ui); font-size: var(--fs-xs); font-weight: 500;
    letter-spacing: 0.16em; text-transform: uppercase; color: var(--ink-faint);
  }
  .input {
    font-family: var(--font-display); font-size: var(--fs-md);
    font-weight: 400;
    background: transparent;
    border: none;
    border-bottom: 1px solid var(--hairline-strong);
    padding: 8px 0;
    color: var(--ink);
    transition: border-color var(--t) var(--ease-out);
    width: 100%;
  }
  .input:focus { border-bottom-color: var(--gold); outline: none; }

  /* Hairline rule */
  .rule { height: 1px; background: var(--hairline); border: 0; }
  .rule-gold { height: 1px; background: var(--gold); border: 0; }

  /* Card primitive */
  .card {
    background: var(--bone);
    border: 1px solid var(--hairline);
    border-radius: var(--r-md);
    padding: var(--s-7);
    transition: border-color var(--t) var(--ease-out),
                transform var(--t) var(--ease-out),
                box-shadow var(--t) var(--ease-out);
  }
  .card:hover { border-color: var(--ink); transform: translateY(-2px); box-shadow: var(--shadow); }

  /* Site nav (used on home + protected pages) */
  .site-nav {
    position: sticky; top: 0; z-index: 100;
    background: rgba(250,247,240,.85);
    backdrop-filter: saturate(180%) blur(14px);
    -webkit-backdrop-filter: saturate(180%) blur(14px);
    border-bottom: 1px solid var(--hairline);
  }
  .nav-inner {
    display: flex; align-items: center; justify-content: space-between;
    padding-block: 18px;
  }
  .nav-logo {
    display: inline-flex; align-items: center; gap: 10px;
    font-family: var(--font-display); font-size: var(--fs-md); font-weight: 500;
    letter-spacing: -0.01em; color: var(--ink);
  }
  .nav-logo:hover { color: var(--ink); }
  .nav-logo-mark {
    width: 26px; height: 26px;
    background: var(--ink); color: var(--gold);
    border-radius: 50%;
    display: inline-flex; align-items: center; justify-content: center;
    font-family: var(--font-display); font-size: 13px; font-weight: 600;
  }
  .nav-links {
    display: flex; align-items: center; gap: var(--s-7);
    font-family: var(--font-ui); font-size: var(--fs-sm); font-weight: 500;
  }
  .nav-links a {
    color: var(--ink-soft);
    padding-block: 4px;
    border-bottom: 1px solid transparent;
    transition: color var(--t) var(--ease-out), border-color var(--t) var(--ease-out);
  }
  .nav-links a:hover, .nav-links a.active { color: var(--ink); border-color: var(--gold); }
  .nav-pill {
    display: inline-flex; align-items: center; gap: 8px;
    padding: 6px 6px 6px 14px;
    border: 1px solid var(--hairline-strong); border-radius: var(--r-pill);
    font-family: var(--font-ui); font-size: var(--fs-xs); font-weight: 500;
    color: var(--ink-soft);
    transition: border-color var(--t) var(--ease-out);
  }
  .nav-pill:hover { border-color: var(--ink); color: var(--ink); }
  .nav-pill-avatar {
    width: 28px; height: 28px; border-radius: 50%;
    background: var(--bone-deep) center/cover no-repeat;
    border: 1px solid var(--hairline-strong);
  }

  @media (max-width: 760px) {
    .nav-links { display: none; }
  }

  /* Nav dropdown — Phases */
  .nav-dropdown { position: relative; }
  .nav-dropdown-toggle {
    appearance: none; background: transparent; border: none; cursor: pointer;
    padding: 4px 0;
    font: inherit; color: var(--ink-soft);
    border-bottom: 1px solid transparent;
    display: inline-flex; align-items: center; gap: 6px;
    transition: color var(--t-fast) var(--ease-out), border-color var(--t-fast) var(--ease-out);
  }
  .nav-dropdown-toggle:hover { color: var(--ink); }
  .nav-dropdown-toggle.active { color: var(--ink); border-bottom-color: var(--gold); }
  .nav-dropdown-toggle:focus-visible { outline: 2px solid var(--gold); outline-offset: 4px; }
  .nav-dropdown-caret { transition: transform var(--t) var(--ease-out); }
  .nav-dropdown-toggle[aria-expanded="true"] .nav-dropdown-caret { transform: rotate(180deg); }

  .nav-dropdown-menu {
    position: absolute; top: calc(100% + 12px); left: -16px;
    min-width: 300px;
    background: rgba(255,255,255,0.98);
    backdrop-filter: saturate(180%) blur(12px);
    -webkit-backdrop-filter: saturate(180%) blur(12px);
    border: 1px solid var(--hairline-strong);
    border-radius: var(--r-md);
    padding: 6px;
    list-style: none; margin: 0;
    opacity: 0; visibility: hidden; transform: translateY(-4px);
    transition: opacity var(--t) var(--ease-out), transform var(--t) var(--ease-out), visibility 0s linear var(--t);
    z-index: 200;
    box-shadow: 0 16px 40px rgba(0,0,0,.08), 0 2px 6px rgba(0,0,0,.04);
  }
  .nav-dropdown:hover .nav-dropdown-menu,
  .nav-dropdown-toggle[aria-expanded="true"] + .nav-dropdown-menu {
    opacity: 1; visibility: visible; transform: translateY(0);
    transition-delay: 0s;
  }
  .nav-dropdown-menu li { margin: 0; }
  .nav-dropdown-menu a {
    display: flex; align-items: baseline; gap: 14px;
    padding: 12px 14px;
    border-radius: var(--r-sm);
    color: var(--ink-soft); text-decoration: none;
    border-bottom: none;
    transition: background var(--t-fast) var(--ease-out), color var(--t-fast) var(--ease-out);
  }
  .nav-dropdown-menu a:hover {
    background: var(--bone-warm);
    color: var(--ink);
  }
  .nav-dropdown-menu .dd-num {
    font-family: var(--font-mono); font-size: var(--fs-xs);
    letter-spacing: 0.14em; color: var(--gold);
    flex-shrink: 0;
  }
  .nav-dropdown-menu .dd-label {
    font-size: var(--fs-sm); font-weight: 500;
    line-height: 1.3;
  }
  @media (max-width: 760px) {
    .nav-dropdown-menu {
      left: -8px; min-width: 260px;
      max-width: calc(100vw - 32px);
    }
  }

  /* Footer */
  .site-footer {
    background: var(--ink); color: var(--bone);
    padding: var(--s-11) 0 var(--s-7);
  }
  .site-footer p, .site-footer a { color: rgba(250,247,240,.65); }
  .site-footer a:hover { color: var(--gold); }
  .footer-grid {
    display: grid; grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: var(--s-9);
    padding-bottom: var(--s-9);
    border-bottom: 1px solid rgba(250,247,240,.10);
  }
  .footer-brand-mark {
    font-family: var(--font-display); font-size: var(--fs-lg); font-weight: 500;
    color: var(--bone); margin-bottom: var(--s-3);
    display: inline-flex; align-items: center; gap: 10px;
  }
  .footer-brand-mark::before {
    content: ""; width: 8px; height: 8px; background: var(--gold); border-radius: 50%;
  }
  .footer-tagline { font-family: var(--font-display); font-style: italic; max-width: 38ch; }
  .footer-col-title {
    font-family: var(--font-ui); font-size: var(--fs-xs); font-weight: 600;
    letter-spacing: 0.18em; text-transform: uppercase;
    color: var(--bone); margin-bottom: var(--s-4);
  }
  .footer-links { display: flex; flex-direction: column; gap: 10px; font-size: var(--fs-sm); }
  .footer-bottom {
    display: flex; justify-content: space-between; flex-wrap: wrap; gap: var(--s-3);
    margin-top: var(--s-6); font-family: var(--font-mono); font-size: var(--fs-xs);
    color: rgba(250,247,240,.55);
  }
  .footer-bottom .credit {
    flex: 1; min-width: 30ch;
  }
  .footer-bottom .cc-license {
    display: inline-flex; align-items: center; gap: 8px;
    color: var(--gold);
  }
  .footer-bottom .cc-license svg {
    width: 22px; height: 22px;
    color: var(--gold);
  }

  /* Rotating bequest quote in footer (above link grid) */
  .footer-bequest {
    padding: var(--s-9) 0 var(--s-7);
    text-align: center;
    border-bottom: 1px solid rgba(250,247,240,.10);
    margin-bottom: var(--s-9);
  }
  .footer-bequest-eyebrow {
    font-family: var(--font-mono); font-size: var(--fs-xs);
    letter-spacing: 0.24em; text-transform: uppercase;
    color: var(--gold); margin-bottom: var(--s-5);
  }
  .footer-bequest-quote {
    font-family: var(--font-display); font-style: italic;
    font-size: clamp(1.25rem, 1rem + 1vw, 1.875rem);
    font-weight: 300; line-height: 1.4;
    letter-spacing: -0.015em;
    color: var(--bone);
    max-width: 720px; margin: 0 auto;
    text-wrap: balance;
    font-variation-settings: "opsz" 144, "SOFT" 50;
    min-height: 1.4em;
  }
  .footer-bequest-quote::before, .footer-bequest-quote::after {
    color: var(--gold); display: inline;
  }
  .footer-bequest-quote::before { content: "\201C"; margin-right: 4px; }
  .footer-bequest-quote::after { content: "\201D"; margin-left: 4px; }
  @media (max-width: 760px) {
    .footer-grid { grid-template-columns: 1fr 1fr; }
  }
}

@layer utilities {
  .sr-only {
    position: absolute !important;
    width: 1px; height: 1px;
    padding: 0; margin: -1px;
    overflow: hidden; clip: rect(0,0,0,0);
    white-space: nowrap; border: 0;
  }
  .text-mono { font-family: var(--font-mono); }
  .text-display { font-family: var(--font-display); }
  .text-italic { font-style: italic; }
  .text-gold { color: var(--gold); }
  .text-crimson { color: var(--crimson); }
  .text-faint { color: var(--ink-faint); }
  .stack-2 > * + * { margin-top: var(--s-2); }
  .stack-3 > * + * { margin-top: var(--s-3); }
  .stack-4 > * + * { margin-top: var(--s-4); }
  .stack-5 > * + * { margin-top: var(--s-5); }
  .stack-7 > * + * { margin-top: var(--s-7); }
  .stack-8 > * + * { margin-top: var(--s-8); }
}

/* ─── Bilingual EN ↔ TH toggle ─────────────────────────────── */
/* Default: Thai content hidden when English is active, vice versa */
html[data-lang="en"] [lang="th"]:not(html) { display: none; }
html[data-lang="th"] [lang="en"]:not(html) { display: none; }
/* Force Thai-only or English-only nodes */
html[data-lang="en"] .only-th { display: none; }
html[data-lang="th"] .only-en { display: none; }

.lang-toggle {
  display: inline-flex; align-items: center; gap: 0;
  padding: 4px;
  background: var(--bone-warm);
  border: 1px solid var(--hairline-strong);
  border-radius: var(--r-pill);
  font-family: var(--font-mono); font-size: var(--fs-xs);
  letter-spacing: 0.10em;
  cursor: pointer;
  transition: border-color var(--t) var(--ease-out);
}
.lang-toggle:hover { border-color: var(--ink); }
.lang-toggle .lang-opt {
  padding: 5px 12px;
  border-radius: var(--r-pill);
  color: var(--ink-faint);
  transition: background var(--t) var(--ease-out), color var(--t) var(--ease-out);
}
html[data-lang="en"] .lang-toggle .lang-opt[data-lang-opt="en"],
html[data-lang="th"] .lang-toggle .lang-opt[data-lang-opt="th"] {
  background: var(--ink); color: var(--bone);
}

/* Cross-page transition (View Transitions API) */
@view-transition { navigation: auto; }
::view-transition-old(root) { animation: vt-fade-out 280ms var(--ease-out) both; }
::view-transition-new(root) { animation: vt-fade-in 320ms var(--ease-out) 80ms both; }
@keyframes vt-fade-out { to { opacity: 0; transform: translateY(-8px); } }
@keyframes vt-fade-in  { from { opacity: 0; transform: translateY(8px); } }

/* Scroll-reveal helper (progressive enhancement; if JS off, content is visible) */
.reveal {
  opacity: 0; transform: translateY(16px);
  transition: opacity 700ms var(--ease-out), transform 700ms var(--ease-out);
}
.reveal.in { opacity: 1; transform: translateY(0); }
@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; }
}