/* ---------- Tom · Teacher of Music ---------- */
/* Editorial music-teaching. Light-themed. Pure white. */

:root {
  /* Type stack — set as CSS vars so Tweaks can swap */
  --font-display: "Fraunces", "Freight Big Pro", Georgia, serif;
  --font-body: "Source Serif 4", "Source Serif Pro", Georgia, serif;

  /* Canvas + ink */
  --canvas: #FFFFFF;
  --ink: #1A1A1A;
  --ink-soft: #4a4a4a;
  --ink-mute: #7a7a7a;
  --rule: #E6E2DC;
  --rule-soft: #F1ECE4;

  /* Scriabin 12 — circle of fifths */
  --c:    #FF0000;
  --csh:  #8B00FF;
  --d:    #FFFF00;
  --dsh:  #5F9EA0;
  --e:    #87CEEB;
  --f:    #8B0000;
  --fsh:  #0066FF;
  --g:    #FF7F50;
  --gsh:  #B284BE;
  --a:    #00C000;
  --ash:  #CD7F32;
  --b:    #A0D8EF;

  /* Diff overlay semantics (also Scriabin-derived) */
  --diff-correct: #00C000;   /* A — green */
  --diff-timing:  #CD7F32;   /* A♯/B♭ — bronze (amber) */
  --diff-wrong:   #8B0000;   /* F — deep red */
  --diff-missed:  #B7B7B7;

  /* Spacing scale */
  --gutter: clamp(20px, 4vw, 56px);
  --col: min(1180px, calc(100vw - var(--gutter) * 2));
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--canvas);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 18px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  font-feature-settings: "kern", "liga", "onum";
}

::selection { background: #1A1A1A; color: #fff; }

img, svg { display: block; max-width: 100%; }

a {
  color: var(--ink);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
  text-decoration-color: rgba(26,26,26,0.35);
  transition: text-decoration-color .2s ease;
}
a:hover { text-decoration-color: var(--ink); }
a:focus-visible {
  outline: 2px solid var(--fsh);
  outline-offset: 3px;
  border-radius: 2px;
}

/* ---------- Header ---------- */
.site-header {
  position: absolute;
  top: 0; left: 0; right: 0;
  z-index: 30;
  padding: 22px var(--gutter);
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  font-family: var(--font-body);
}
.brand {
  font-family: var(--font-display);
  font-weight: 500;
  font-size: 20px;
  letter-spacing: -0.01em;
  text-decoration: none;
}
.brand .brand-mark {
  display: inline-block;
  width: 9px; height: 9px;
  border-radius: 50%;
  background: var(--ink);
  margin-right: 9px;
  transform: translateY(-2px);
}
.nav {
  display: flex;
  gap: 26px;
  font-size: 14px;
  letter-spacing: 0.01em;
}
.nav a {
  text-decoration: none;
  color: var(--ink-soft);
  position: relative;
  padding-bottom: 3px;
}
.nav a:hover { color: var(--ink); }
.nav a[aria-current="page"] {
  color: var(--ink);
  font-weight: 600;
}
.nav a[aria-current="page"]::after {
  content: "";
  position: absolute;
  left: 0; right: 0; bottom: 0;
  height: 1.5px;
  background: var(--ink);
}

/* ---------- Hero ---------- */
.hero {
  position: relative;
  min-height: 100vh;
  padding: clamp(120px, 14vh, 180px) var(--gutter) clamp(60px, 8vh, 100px);
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(0, 1fr);
  gap: clamp(32px, 5vw, 80px);
  align-items: center;
  overflow: hidden;
}
.hero-copy {
  position: relative;
  z-index: 2;
  max-width: 560px;
}
.eyebrow {
  font-family: var(--font-body);
  font-size: 13px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--ink-mute);
  margin: 0 0 28px;
  display: flex;
  align-items: center;
  gap: 12px;
}
.eyebrow::before {
  content: "";
  width: 28px; height: 1px;
  background: var(--ink-mute);
  display: inline-block;
}

.hero h1 {
  font-family: var(--font-display);
  font-weight: 400;
  font-size: clamp(48px, 7.4vw, 104px);
  line-height: 0.96;
  letter-spacing: -0.025em;
  margin: 0 0 32px;
  font-variation-settings: "SOFT" 30, "WONK" 0, "opsz" 144;
}
.hero h1 .line {
  display: block;
}
.hero h1 .line-2 {
  font-style: italic;
  font-variation-settings: "SOFT" 50, "WONK" 1, "opsz" 144;
  color: var(--ink);
}
.hero h1 .line-3 {
  font-size: 0.40em;
  font-style: normal;
  font-weight: 400;
  letter-spacing: -0.005em;
  color: var(--ink-soft);
  font-family: var(--font-body);
  line-height: 1.25;
  margin-top: 22px;
  max-width: 14ch;
}

.hero-lede {
  font-size: 18px;
  line-height: 1.6;
  color: var(--ink);
  max-width: 50ch;
  margin: 0;
  text-wrap: pretty;
}
.hero-lede em {
  font-style: italic;
  color: var(--ink);
}

.hero-visual {
  position: relative;
  z-index: 1;
  align-self: center;
  justify-self: center;
  width: 100%;
  max-width: 620px;
  aspect-ratio: 1 / 1;
  overflow: hidden;
}
.hero-visual > svg {
  display: block;
  width: 100%;
  height: 100%;
  overflow: hidden;
}

/* ---------- Section frame ---------- */
.section {
  padding: clamp(80px, 12vh, 160px) var(--gutter);
  position: relative;
}
.section-inner {
  width: var(--col);
  margin: 0 auto;
}

.section-head {
  display: grid;
  grid-template-columns: 200px 1fr;
  gap: clamp(20px, 4vw, 56px);
  align-items: baseline;
  margin-bottom: clamp(40px, 6vh, 72px);
  padding-bottom: 28px;
  border-bottom: 1px solid var(--rule);
}
.section-num {
  font-family: var(--font-body);
  font-size: 13px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--ink-mute);
  font-feature-settings: "lnum";
}
.section-title {
  font-family: var(--font-display);
  font-weight: 400;
  font-size: clamp(36px, 5.2vw, 72px);
  line-height: 1;
  letter-spacing: -0.02em;
  margin: 0;
  font-variation-settings: "SOFT" 30, "opsz" 144;
}
.section-title em {
  font-style: italic;
  font-variation-settings: "SOFT" 50, "WONK" 1, "opsz" 144;
}

.section-opener {
  font-family: var(--font-display);
  font-weight: 300;
  font-size: clamp(22px, 2.4vw, 30px);
  line-height: 1.35;
  letter-spacing: -0.01em;
  color: var(--ink);
  max-width: 30ch;
  margin: 0 0 clamp(48px, 6vh, 80px);
  text-wrap: balance;
}
.section-opener em {
  font-style: italic;
}

/* Editorial body grid */
.beat {
  display: grid;
  grid-template-columns: 200px minmax(0, 1fr);
  gap: clamp(20px, 4vw, 56px);
  padding: clamp(28px, 4vh, 48px) 0;
  border-top: 1px solid var(--rule-soft);
}
.beat:first-of-type { border-top: none; padding-top: 0; }
.beat-marker {
  font-family: var(--font-body);
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--ink-mute);
  padding-top: 6px;
  font-feature-settings: "lnum";
}
.beat-body {
  max-width: 65ch;
  font-size: clamp(17px, 1.18vw, 19px);
  line-height: 1.62;
  color: var(--ink);
  text-wrap: pretty;
}
.beat-body p { margin: 0 0 1.2em; }
.beat-body p:last-child { margin-bottom: 0; }
.beat-body strong.lede {
  font-family: var(--font-display);
  font-weight: 500;
  font-size: 1.08em;
  letter-spacing: -0.005em;
}

.section-close {
  margin-top: clamp(40px, 6vh, 72px);
  padding-top: clamp(28px, 4vh, 40px);
  border-top: 1px solid var(--rule);
  font-family: var(--font-display);
  font-weight: 300;
  font-style: italic;
  font-size: clamp(20px, 2vw, 26px);
  line-height: 1.4;
  color: var(--ink);
  max-width: 50ch;
  text-wrap: pretty;
}

/* ---------- Architecture diagram wrapper ---------- */
.arch-wrap {
  margin: clamp(48px, 7vh, 88px) 0;
  padding: clamp(32px, 5vw, 56px) clamp(20px, 4vw, 48px);
  background:
    /* paper grain via SVG noise — see HTML */
    var(--paper-grain, transparent),
    #FDFCFA;
  border: 1px solid var(--rule);
  border-radius: 2px;
  position: relative;
}
.arch-caption {
  font-family: var(--font-body);
  font-size: 13px;
  letter-spacing: 0.04em;
  color: var(--ink-mute);
  margin-top: 20px;
  text-align: center;
  font-style: italic;
}
.arch-svg { width: 100%; height: auto; }

/* ---------- Multimodal stack list ---------- */
.stack-intro {
  font-family: var(--font-display);
  font-weight: 400;
  font-size: clamp(20px, 1.7vw, 24px);
  line-height: 1.4;
  margin: 0 0 28px;
  color: var(--ink);
}
.stack-intro em { font-style: italic; }

.stack {
  list-style: none;
  margin: 0 0 clamp(40px, 5vh, 64px);
  padding: 0;
  border-top: 1px solid var(--rule);
}
.stack li {
  display: grid;
  grid-template-columns: 130px 1fr auto;
  gap: clamp(16px, 2.5vw, 32px);
  align-items: baseline;
  padding: 18px 0;
  border-bottom: 1px solid var(--rule-soft);
}
.stack .modality {
  font-family: var(--font-display);
  font-weight: 500;
  font-size: clamp(18px, 1.4vw, 22px);
  letter-spacing: -0.005em;
  color: var(--ink);
}
.stack .modality .glyph {
  display: inline-block;
  width: 18px; height: 18px;
  border-radius: 50%;
  margin-right: 10px;
  vertical-align: -3px;
}
.stack .desc {
  font-size: clamp(15px, 1.05vw, 17px);
  line-height: 1.55;
  color: var(--ink-soft);
  text-wrap: pretty;
}
.stack .state {
  font-family: var(--font-body);
  font-size: 11px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  padding: 4px 10px;
  border-radius: 999px;
  white-space: nowrap;
  border: 1px solid currentColor;
  font-weight: 600;
}
.state.live    { color: #1f6b1f; background: rgba(0,192,0,0.06); }
.state.partial { color: #8a5418; background: rgba(205,127,50,0.06); }
.state.arch    { color: var(--ink-mute); background: transparent; }

/* Modality dot color */
.m-text   .glyph { background: var(--fsh); }
.m-vision .glyph { background: var(--gsh); }
.m-time   .glyph { background: var(--ash); }
.m-score  .glyph { background: var(--ink); }
.m-midi   .glyph { background: var(--csh); }
.m-audio  .glyph { background: var(--g); }

/* ---------- Sheet-music diff ---------- */
.diff-wrap {
  margin: clamp(48px, 7vh, 88px) 0 0;
  padding: clamp(28px, 4vw, 48px) clamp(20px, 4vw, 40px);
  background: #FFFFFF;
  border: 1px solid var(--rule);
  border-radius: 2px;
}
.diff-svg { width: 100%; height: auto; }
.diff-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 18px 28px;
  justify-content: center;
  margin-top: 22px;
  font-size: 12.5px;
  letter-spacing: 0.04em;
  color: var(--ink-soft);
}
.diff-legend span { display: inline-flex; align-items: center; gap: 8px; }
.diff-legend i {
  width: 12px; height: 12px;
  border-radius: 2px;
  display: inline-block;
}

/* ---------- Footer ---------- */
.site-footer {
  padding: clamp(80px, 12vh, 140px) var(--gutter) 32px;
  text-align: center;
  font-size: 14.5px;
  color: var(--ink-soft);
  letter-spacing: 0.02em;
}
.site-footer .contact {
  display: inline-flex;
  align-items: center;
  gap: 14px;
  flex-wrap: wrap;
  justify-content: center;
}
.site-footer .dot {
  width: 3px; height: 3px;
  border-radius: 50%;
  background: var(--ink-mute);
  display: inline-block;
}
.back-home {
  display: block;
  margin: 64px auto 0;
  font-family: var(--font-display);
  font-style: italic;
  font-size: 15px;
  color: var(--ink-soft);
  text-decoration: none;
  width: max-content;
}
.back-home:hover { color: var(--ink); }

/* ---------- Archie chat button ---------- */
.archie {
  position: fixed;
  right: clamp(18px, 2.5vw, 32px);
  bottom: clamp(18px, 2.5vw, 32px);
  z-index: 50;
}
.archie-btn {
  width: 54px; height: 54px;
  border-radius: 50%;
  background: var(--ink);
  color: #fff;
  border: none;
  cursor: pointer;
  display: grid;
  place-items: center;
  box-shadow:
    0 1px 2px rgba(0,0,0,0.10),
    0 8px 24px rgba(0,0,0,0.18);
  transition: transform .2s ease, box-shadow .2s ease;
  font-family: var(--font-display);
}
.archie-btn:hover {
  transform: translateY(-1px);
  box-shadow:
    0 1px 2px rgba(0,0,0,0.12),
    0 12px 30px rgba(0,0,0,0.22);
}
.archie-btn:focus-visible {
  outline: 2px solid var(--fsh);
  outline-offset: 4px;
}
.archie-btn svg { width: 22px; height: 22px; }

.archie-tooltip {
  position: absolute;
  right: 64px;
  bottom: 6px;
  background: #1A1A1A;
  color: #fff;
  font-family: var(--font-body);
  font-size: 13.5px;
  line-height: 1.4;
  padding: 10px 14px;
  border-radius: 6px;
  white-space: nowrap;
  opacity: 0;
  transform: translateX(8px);
  transition: opacity .35s ease, transform .35s ease;
  pointer-events: none;
  box-shadow: 0 6px 20px rgba(0,0,0,0.18);
}
.archie-tooltip::after {
  content: "";
  position: absolute;
  right: -5px;
  top: 50%;
  transform: translateY(-50%) rotate(45deg);
  width: 10px; height: 10px;
  background: #1A1A1A;
}
.archie-tooltip.show {
  opacity: 1;
  transform: translateX(0);
}

/* ---------- Tweaks panel (vanilla) ---------- */
.tweaks-panel {
  position: fixed;
  right: 24px;
  bottom: 96px;
  width: 280px;
  background: #fff;
  border: 1px solid #1A1A1A;
  border-radius: 4px;
  padding: 18px 18px 16px;
  font-family: var(--font-body);
  font-size: 13.5px;
  z-index: 60;
  box-shadow: 0 14px 40px rgba(0,0,0,0.16);
  display: none;
}
.tweaks-panel.open { display: block; }
.tweaks-panel h3 {
  font-family: var(--font-display);
  font-weight: 500;
  margin: 0 0 14px;
  font-size: 18px;
  letter-spacing: -0.01em;
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.tweaks-panel .tw-close {
  background: none; border: none; font-size: 18px; cursor: pointer;
  color: var(--ink-mute); padding: 0; line-height: 1;
}
.tweaks-panel label {
  display: block;
  font-size: 11px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ink-mute);
  margin: 12px 0 6px;
}
.tweaks-panel select,
.tweaks-panel input[type=range] {
  width: 100%;
  font-family: inherit;
  font-size: 13px;
}
.tweaks-panel select {
  padding: 6px 8px;
  border: 1px solid var(--rule);
  background: #fff;
  border-radius: 2px;
}
.tweaks-panel .tw-row {
  display: flex; justify-content: space-between; align-items: center;
  margin-top: 6px;
  color: var(--ink-soft);
  font-size: 12px;
}

/* ---------- Responsive ---------- */
@media (max-width: 1024px) {
  .hero {
    grid-template-columns: minmax(0, 1fr) minmax(0, 0.6fr);
    gap: clamp(20px, 3vw, 40px);
    padding-top: clamp(110px, 16vh, 160px);
  }
  .hero-visual { max-width: 320px; }
  .section-head {
    grid-template-columns: 1fr;
    gap: 12px;
  }
  .beat { grid-template-columns: 1fr; gap: 14px; }
  .beat-marker { padding-top: 0; }
}

@media (max-width: 720px) {
  .hero {
    grid-template-columns: 1fr;
    gap: clamp(24px, 4vw, 48px);
  }
  .hero-visual { max-width: 380px; order: 2; }
  .hero-copy { order: 1; }

  body { font-size: 17px; }
  .nav { gap: 16px; font-size: 13px; }
  .brand { font-size: 17px; }
  .hero { padding-top: 96px; }
  .hero h1 { font-size: clamp(40px, 12vw, 68px); }
  .hero h1 .line-3 { font-size: 0.46em; max-width: 16ch; }
  .stack li {
    grid-template-columns: 1fr auto;
    grid-template-areas:
      "modality state"
      "desc desc";
    gap: 4px 12px;
    padding: 16px 0;
  }
  .stack .modality { grid-area: modality; }
  .stack .state    { grid-area: state; justify-self: end; }
  .stack .desc     { grid-area: desc; margin-top: 4px; }
  .arch-wrap { padding: 22px 14px; }
  .tweaks-panel { right: 12px; left: 12px; width: auto; }
  .archie { right: 14px; bottom: 14px; }
}

@media (max-width: 420px) {
  .hero h1 { font-size: clamp(38px, 13vw, 56px); }
  .section { padding-top: 64px; padding-bottom: 64px; }
  .section-title { font-size: clamp(32px, 10vw, 48px); }
  .nav { display: none; }
  .nav.compact { display: flex; }
}

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
  * { animation-duration: 0.001s !important; transition-duration: 0.01s !important; }
}