/* ============================================================
   Two Notes — art direction: Jason's iPad whiteboards.
   Warm paper, ink, and the exact marker colours from class.
   ============================================================ */

:root {
  --paper: #f5f2ea;
  --card: #fdfbf4;
  --ink: #23201a;
  --ink-soft: #5b554a;
  --line: #d8d2c2;

  --red: #d9402a;      /* tension */
  --teal: #0f8b8d;     /* anticipation */
  --gold: #c8912b;     /* emotional consonance */
  --green: #2c6e49;    /* perfect consonance / resolution */
  --purple: #6a3ea1;
  --magenta: #b02e77;
  --blue: #2b5fb8;

  --serif: "Cormorant Garamond", Georgia, serif;
  --sans: "Archivo", -apple-system, sans-serif;
  --mono: "IBM Plex Mono", ui-monospace, monospace;
}

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

[hidden] { display: none !important; }

html { scroll-behavior: smooth; }

body {
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

/* paper grain */
body::before {
  content: "";
  position: fixed; inset: 0; z-index: 0; pointer-events: none;
  opacity: 0.5;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='240' height='240'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2'/%3E%3CfeColorMatrix values='0 0 0 0 0.55 0 0 0 0 0.52 0 0 0 0 0.46 0 0 0 0.05 0'/%3E%3C/filter%3E%3Crect width='240' height='240' filter='url(%23n)'/%3E%3C/svg%3E");
}

main, header, footer { position: relative; z-index: 1; }

/* ---------- masthead ---------- */

.masthead { padding: 40px 24px 0; max-width: 1080px; margin: 0 auto; }
.masthead-inner { display: flex; align-items: flex-end; gap: 26px; flex-wrap: wrap; }
.nsm-logo { height: 44px; width: auto; }
.masthead-title h1 {
  font-family: var(--serif); font-weight: 700; font-size: clamp(44px, 7vw, 76px);
  line-height: 0.95; letter-spacing: -0.01em;
}
.masthead-title .amp { font-style: italic; color: var(--red); }
.tagline { font-size: 17px; color: var(--ink-soft); margin-top: 6px; }
.tagline em { font-family: var(--serif); font-size: 19px; }

/* chapter nav — circled marker numbers */
.chapters {
  display: flex; gap: 8px; flex-wrap: wrap;
  margin: 30px 0 0; padding-bottom: 16px;
  border-bottom: 2px solid var(--ink);
}
.chapters button {
  font-family: var(--sans); font-weight: 600; font-size: 14.5px;
  background: none; border: 1.8px solid transparent; border-radius: 999px;
  color: var(--ink-soft); padding: 9px 16px; cursor: pointer;
  display: flex; align-items: center; gap: 9px;
  transition: all 0.15s ease;
}
.chapters button .num {
  font-family: var(--mono); font-size: 12.5px;
  width: 23px; height: 23px; border-radius: 50%;
  border: 1.6px solid currentColor;
  display: grid; place-items: center;
  transform: rotate(-4deg);
}
.chapters button:hover { color: var(--ink); border-color: var(--line); }
.chapters button.active { color: var(--card); background: var(--ink); border-color: var(--ink); }

/* ---------- chapters ---------- */

#app { max-width: 1080px; margin: 0 auto; padding: 42px 24px 80px; }
.chapter { display: none; }
.chapter.visible { display: block; animation: chapterIn 0.35s ease; }
@keyframes chapterIn { from { opacity: 0; transform: translateY(10px); } }

.ch-head { margin-bottom: 34px; max-width: 760px; }
.ch-kicker {
  font-family: var(--mono); font-size: 13px; font-weight: 600;
  text-transform: uppercase; letter-spacing: 0.14em; color: var(--red);
  margin-bottom: 8px;
}
.ch-head h2 {
  font-family: var(--serif); font-weight: 700;
  font-size: clamp(34px, 4.6vw, 52px); line-height: 1.02;
  margin-bottom: 4px;
}
.ch-head .under {
  display: block; width: 190px; height: 12px; margin: 6px 0 16px;
}
.ch-lede { font-size: 17.5px; color: var(--ink-soft); }
.ch-lede strong { color: var(--ink); }
.ch-lede em { font-family: var(--serif); font-size: 19px; color: var(--ink); }

/* ---------- shared components ---------- */

.card {
  background: var(--card); border: 1.6px solid var(--ink);
  border-radius: 14px; padding: 24px;
  box-shadow: 3px 4px 0 rgba(35, 32, 26, 0.12);
}

.btn {
  font-family: var(--sans); font-weight: 600; font-size: 14.5px;
  border: 1.7px solid var(--ink); border-radius: 999px;
  background: var(--card); color: var(--ink);
  padding: 9px 18px; cursor: pointer;
  transition: all 0.13s ease;
  display: inline-flex; align-items: center; gap: 8px;
}
.btn:hover { background: var(--ink); color: var(--card); }
.btn:active { transform: translateY(1.5px); }
.btn.primary { background: var(--ink); color: var(--card); }
.btn.primary:hover { background: var(--red); border-color: var(--red); }
.btn.small { padding: 6px 13px; font-size: 13px; }
.btn.ghost { border-style: dashed; border-color: var(--ink-soft); color: var(--ink-soft); }
.btn.ghost:hover { border-color: var(--ink); color: var(--ink); background: var(--card); }

.chip {
  font-family: var(--mono); font-size: 12.5px; font-weight: 600;
  padding: 4px 11px; border-radius: 999px; border: 1.5px solid currentColor;
  display: inline-block;
}
.chip.f-perfect { color: var(--green); }
.chip.f-emotional { color: var(--gold); }
.chip.f-tension { color: var(--red); }
.chip.f-anticipation { color: var(--teal); }

.mono { font-family: var(--mono); }

.stave-box { color: var(--ink); max-width: 620px; }
.stave-box svg { display: block; }

/* keyboard */
.kbd-svg { width: 100%; height: auto; display: block; }
.kbd-white-rect { fill: #fffef9; stroke: var(--ink); stroke-width: 1.5; cursor: pointer; }
.kbd-black-rect { fill: var(--ink); stroke: var(--ink); stroke-width: 1.5; cursor: pointer; }
.kbd-key:hover rect:not(.marked) { fill: #efe9d9; }
.kbd-key:hover .kbd-black-rect:not(.marked) { fill: #4a4437; }
.kbd-label { font-family: var(--sans); font-weight: 700; font-size: 13px; fill: #fff; pointer-events: none; }
.kbd-label-black { font-size: 11.5px; }

/* ---------- chapter 1 : Start With Two ---------- */

.two-grid { display: grid; grid-template-columns: 1.05fr 0.95fr; gap: 26px; align-items: start; }
@media (max-width: 900px) { .two-grid { grid-template-columns: 1fr; } }

.eb-result { min-height: 118px; display: flex; flex-direction: column; gap: 8px; justify-content: center; }
.eb-result .big {
  font-family: var(--serif); font-style: italic; font-weight: 600;
  font-size: clamp(26px, 3.4vw, 36px); line-height: 1.1;
}
.eb-result .pair { font-family: var(--mono); font-size: 15px; color: var(--ink-soft); }

.quote-block {
  position: relative;
  padding: 26px 0 4px 34px; margin-top: 22px;
  font-family: var(--serif); font-size: 20px; font-style: italic; line-height: 1.45;
  color: var(--ink);
  max-width: 640px;
}
.quote-block::before {
  content: "\201C";
  position: absolute; left: 0; top: 22px;
  font-family: var(--serif); font-style: normal;
  font-size: 64px; line-height: 1; color: var(--red);
}
.quote-block .who { display: block; font-family: var(--mono); font-style: normal; font-size: 12.5px; color: var(--ink-soft); margin-top: 8px; }

/* ---------- chapter 2 : Families ---------- */

.family-tree { display: grid; grid-template-columns: repeat(auto-fit, minmax(230px, 1fr)); gap: 16px; margin-bottom: 30px; }
.family-card { border-radius: 14px; border: 1.7px solid; padding: 18px 18px 15px; background: var(--card); }
.family-card h3 { font-family: var(--serif); font-size: 24px; font-weight: 700; line-height: 1.05; }
.family-card .vibe { font-family: var(--serif); font-style: italic; font-size: 16px; margin: 3px 0 12px; opacity: 0.85; }
.family-card .members { display: flex; flex-wrap: wrap; gap: 7px; }
.family-card .members button {
  font-family: var(--mono); font-size: 13px; font-weight: 600;
  border: 1.5px solid currentColor; background: none; color: inherit;
  border-radius: 8px; padding: 5px 9px; cursor: pointer; transition: all 0.12s;
}
.family-card .members button span { color: inherit; }
.family-card .members button:hover, .family-card .members button.on { background: currentColor; }
.family-card .members button:hover span, .family-card .members button.on span { color: var(--card); }
.family-card .note { font-size: 12.5px; margin-top: 10px; opacity: 0.75; }

.lab-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 26px; align-items: start; }
@media (max-width: 940px) { .lab-grid { grid-template-columns: 1fr; } }
.lab-controls { display: flex; flex-wrap: wrap; gap: 10px; align-items: center; margin-bottom: 18px; }
.lab-readout { margin: 14px 0 6px; }
.lab-readout .iv-name { font-family: var(--serif); font-size: clamp(28px, 3.4vw, 40px); font-weight: 700; line-height: 1.05; }
.lab-readout .iv-notes { font-family: var(--mono); font-size: 16px; color: var(--ink-soft); margin-top: 4px; }
.lab-readout .iv-emotion { font-family: var(--serif); font-style: italic; font-size: 19px; margin-top: 6px; }

select.root-pick {
  font-family: var(--mono); font-size: 15px; font-weight: 600;
  border: 1.7px solid var(--ink); border-radius: 10px; background: var(--card);
  color: var(--ink); padding: 8px 12px; cursor: pointer;
}

/* ---------- chapter 3 : Scales ---------- */

.scale-layout { display: grid; grid-template-columns: 250px 1fr; gap: 26px; align-items: start; }
@media (max-width: 940px) { .scale-layout { grid-template-columns: 1fr; } }
.scale-list { display: flex; flex-direction: column; gap: 6px; }
.scale-list button {
  text-align: left; font-family: var(--sans); font-weight: 600; font-size: 14.5px;
  background: none; border: 1.6px solid transparent; border-radius: 10px;
  padding: 9px 13px; cursor: pointer; color: var(--ink-soft);
  display: flex; justify-content: space-between; align-items: center; gap: 8px;
}
.scale-list button:hover { border-color: var(--line); color: var(--ink); }
.scale-list button.active { border-color: var(--ink); background: var(--card); color: var(--ink); box-shadow: 2px 3px 0 rgba(35,32,26,0.12); }
.scale-list .star { color: var(--gold); font-size: 16px; }

.walk-row { display: flex; flex-wrap: wrap; align-items: flex-end; gap: 0; margin: 20px 0 8px; }
.walk-note {
  font-family: var(--sans); font-weight: 700; font-size: 21px;
  min-width: 46px; text-align: center;
}
.walk-step { text-align: center; padding: 0 2px; min-width: 52px; }
.walk-step .arc { display: block; height: 16px; }
.walk-step .lab { font-family: var(--mono); font-size: 12px; font-weight: 600; display: block; }
.walk-step .semi { font-family: var(--mono); font-size: 11px; color: var(--ink-soft); display: block; }
.walk-step.aug .lab { color: var(--red); }
.walk-step.aug .semi { color: var(--red); font-weight: 700; }

.scale-alias {
  font-family: var(--serif); font-style: italic; font-size: 17.5px;
  color: var(--purple); margin: 10px 0 2px;
}
.decoder { margin-top: 30px; }
.decoder table { border-collapse: collapse; width: 100%; max-width: 560px; }
.decoder td {
  border-bottom: 1.4px dashed var(--line); padding: 9px 10px 9px 0;
  font-size: 15px; vertical-align: top;
}
.decoder td:first-child { font-family: var(--serif); font-weight: 700; font-size: 18px; white-space: nowrap; width: 170px; }
.decoder td .mono { color: var(--red); font-weight: 600; }

/* ---------- chapter 4 : Circle ---------- */

.circle-layout { display: grid; grid-template-columns: 1fr 1.1fr; gap: 30px; align-items: start; }
@media (max-width: 940px) { .circle-layout { grid-template-columns: 1fr; } }

.circle-svg-wrap { max-width: 430px; margin: 0 auto; }
.cof-slot { cursor: pointer; }
.cof-slot circle { fill: var(--card); stroke: var(--line); stroke-width: 1.6; transition: all 0.2s; }
.cof-slot text { font-family: var(--sans); font-weight: 700; font-size: 19px; fill: var(--line); transition: fill 0.2s; }
.cof-slot.lit circle { stroke: var(--ink); fill: #fffef9; }
.cof-slot.lit text { fill: var(--ink); }
.cof-slot.now circle { fill: var(--ink); stroke: var(--ink); }
.cof-slot.now text { fill: var(--card); }
.cof-minor { font-family: var(--serif); font-style: italic; font-size: 12.5px; fill: var(--ink-soft); opacity: 0; transition: opacity 0.25s; }
.cof-minor.lit { opacity: 1; }

.journey-panel .keysig-stave { margin: 6px 0 2px; }
.journey-title { display: flex; align-items: baseline; gap: 14px; flex-wrap: wrap; }
.journey-title .maj { font-family: var(--serif); font-weight: 700; font-size: clamp(30px, 3.6vw, 42px); }
.journey-title .rel { font-family: var(--serif); font-style: italic; font-size: 20px; color: var(--ink-soft); }
.journey-new {
  font-family: var(--mono); font-size: 13.5px; margin: 6px 0 14px; color: var(--purple);
  min-height: 21px;
}
.journey-new .pop { display: inline-block; animation: popIn 0.35s cubic-bezier(0.22, 1, 0.36, 1); }
@keyframes popIn { from { transform: scale(0.6) rotate(-8deg); opacity: 0; } }
.journey-controls { display: flex; gap: 10px; flex-wrap: wrap; margin-top: 6px; }

.modes-reveal { margin-top: 44px; }
.mode-cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(148px, 1fr)); gap: 10px; margin-top: 18px; }
.mode-card {
  border: 1.6px solid var(--line); border-radius: 12px; background: var(--card);
  padding: 12px 13px; cursor: pointer; text-align: left; transition: all 0.14s;
  font-family: var(--sans);
}
.mode-card:hover { border-color: var(--ink); }
.mode-card.active { border-color: var(--ink); box-shadow: 2px 3px 0 rgba(35,32,26,0.12); }
.mode-card .deg { font-family: var(--mono); font-size: 11.5px; color: var(--ink-soft); }
.mode-card .tonic { font-family: var(--serif); font-weight: 700; font-size: 24px; line-height: 1.1; }
.mode-card .mname { font-size: 12.5px; color: var(--ink-soft); }
.mode-detail { margin-top: 18px; }

/* ---------- chapter 5 : Detective ---------- */

.case-file { max-width: 720px; }
.case-tag { font-family: var(--mono); font-size: 12.5px; color: var(--ink-soft); letter-spacing: 0.1em; text-transform: uppercase; }
.case-q { font-family: var(--serif); font-size: 22px; font-weight: 600; margin: 6px 0 14px; }
.case-options { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 16px; }
.case-options .btn.correct { background: var(--green); border-color: var(--green); color: var(--card); }
.case-options .btn.wrong { background: var(--red); border-color: var(--red); color: var(--card); opacity: 0.85; }
.case-explain {
  margin-top: 16px; padding: 14px 16px; border-radius: 12px;
  border: 1.5px dashed var(--green); color: var(--ink);
  font-size: 15px; display: none;
}
.case-explain.show { display: block; animation: chapterIn 0.3s ease; }
.case-explain strong { color: var(--green); }
.case-nav { display: flex; align-items: center; gap: 14px; margin-top: 20px; }
.case-count { font-family: var(--mono); font-size: 13px; color: var(--ink-soft); }

/* ---------- chapter 6 : Gym ---------- */

.gym-picker { display: flex; gap: 10px; flex-wrap: wrap; margin-bottom: 26px; }
.gym-picker .btn.on { background: var(--ink); color: var(--card); }
.drill-box { max-width: 720px; }
.drill-q { font-family: var(--serif); font-size: clamp(22px, 3vw, 30px); font-weight: 600; margin-bottom: 4px; min-height: 40px; }
.drill-sub { color: var(--ink-soft); font-size: 14.5px; margin-bottom: 14px; }
.drill-options { display: flex; flex-wrap: wrap; gap: 9px; margin-top: 14px; }
.drill-options .btn.correct { background: var(--green); border-color: var(--green); color: var(--card); }
.drill-options .btn.wrong { background: var(--red); border-color: var(--red); color: var(--card); opacity: 0.85; }
.drill-score {
  display: flex; gap: 22px; margin-top: 22px; padding-top: 16px;
  border-top: 1.5px dashed var(--line);
  font-family: var(--mono); font-size: 13.5px; color: var(--ink-soft);
}
.drill-score b { color: var(--ink); font-size: 17px; display: block; font-family: var(--sans); }
.streak-fire { color: var(--red); }

/* ---------- footer ---------- */

.colophon {
  border-top: 2px solid var(--ink);
  max-width: 1080px; margin: 30px auto 0; padding: 34px 24px 60px;
  text-align: center; color: var(--ink-soft); font-size: 15px;
}
.nsm-logo-foot { height: 34px; width: auto; margin-bottom: 14px; opacity: 0.9; }
.colophon .fine { font-size: 12.5px; margin-top: 14px; line-height: 1.7; }

.audio-hint {
  position: fixed; bottom: 18px; right: 18px; z-index: 50;
  background: var(--ink); color: var(--card); font-family: var(--mono);
  font-size: 13px; padding: 10px 16px; border-radius: 999px;
}

/* hand-drawn underline helper (inline SVG uses stroke=currentColor) */
.marker-under { color: var(--red); }