/* Single committed visual identity — this is a brand asset and must look
   the same for every viewer, so it does not follow the host theme. Every
   colour is painted explicitly. */
:root {
  --coral: #e2544c;
  --coral-deep: #c53b33;
  --coral-soft: #fdeeec;
  --amber: #ed9035;
  --amber-soft: #fdf1e4;

  --ink: #1c1517;
  --ink-2: #4a3f41;
  --muted: #7d7173;
  --line: #e6dfdc;
  --line-2: #cfc5c1;

  --ground: #fbf8f6;
  --surface: #ffffff;
  --dark: #1c1517;
  --dark-2: #2a2023;
  --dark-line: #453a3d;
  --on-dark: #f6f0ee;
  --on-dark-2: #b6a9ab;

  --serif: "Newsreader", ui-serif, Georgia, serif;
  --sans: "Public Sans", ui-sans-serif, system-ui, -apple-system, sans-serif;
  --mono: "IBM Plex Mono", ui-monospace, Menlo, Consolas, monospace;

  --rail: 232px;
  --measure: 64ch;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  background: var(--ground);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { animation: none !important; transition: none !important; }
}

/* ── Chapter rail ────────────────────────────────────── */

.rail {
  position: fixed;
  inset-block: 0;
  left: 0;
  width: var(--rail);
  background: var(--dark);
  border-right: 1px solid var(--dark-line);
  padding-block: 24px;
  overflow-y: auto;
  z-index: 20;
}

.rail-mark {
  font-family: var(--serif);
  font-size: 19px;
  font-weight: 600;
  color: var(--on-dark);
  padding-inline: 20px;
  margin-bottom: 4px;
}

.rail-mark span { color: var(--coral); }

.rail-sub {
  font-family: var(--mono);
  font-size: 9.5px;
  letter-spacing: 0.13em;
  text-transform: uppercase;
  color: var(--on-dark-2);
  padding-inline: 20px;
  margin-bottom: 22px;
}

.rail a {
  display: flex;
  gap: 10px;
  align-items: baseline;
  padding: 7px 20px;
  color: var(--on-dark-2);
  text-decoration: none;
  font-size: 13px;
  line-height: 1.35;
  border-left: 2px solid transparent;
  transition: color .15s, border-color .15s, background .15s;
}

.rail a:hover { color: var(--on-dark); background: var(--dark-2); }

.rail a.on {
  color: var(--on-dark);
  border-left-color: var(--coral);
  background: var(--dark-2);
}

.rail a b {
  font-family: var(--mono);
  font-size: 10px;
  font-weight: 500;
  color: var(--muted);
  flex: none;
}

.rail a.on b { color: var(--coral); }

.rail a:focus-visible { outline: 2px solid var(--coral); outline-offset: -2px; }

/* ── Stage ───────────────────────────────────────────── */

.stage { margin-left: var(--rail); }

section {
  padding-block: 84px;
  padding-inline: clamp(20px, 5vw, 72px);
}

.band-dark { background: var(--dark); color: var(--on-dark); }
.band-dark p { color: var(--on-dark-2); }

.inner { max-width: 1040px; }

.chapter-no {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--coral);
  margin: 0 0 14px;
}

h1 {
  font-family: var(--serif);
  font-weight: 500;
  font-size: clamp(38px, 6vw, 68px);
  line-height: 1.03;
  letter-spacing: -0.02em;
  margin: 0 0 22px;
  text-wrap: balance;
}

h2 {
  font-family: var(--serif);
  font-weight: 500;
  font-size: clamp(28px, 4vw, 42px);
  line-height: 1.12;
  letter-spacing: -0.015em;
  margin: 0 0 16px;
  text-wrap: balance;
}

h3 {
  font-family: var(--sans);
  font-weight: 600;
  font-size: 16px;
  margin: 0 0 6px;
}

.lede {
  font-size: 19px;
  line-height: 1.5;
  color: var(--ink-2);
  max-width: var(--measure);
  margin: 0 0 30px;
}

.band-dark .lede { color: var(--on-dark-2); }

p { max-width: var(--measure); margin: 0 0 16px; }

em.hl { font-style: normal; color: var(--coral); }

/* ── Hero ────────────────────────────────────────────── */

.hero { padding-block: clamp(72px, 12vh, 120px) 72px; }

.hero h1 { max-width: 15ch; }

.cta-row { display: flex; flex-wrap: wrap; gap: 12px; margin-bottom: 52px; }

.btn {
  display: inline-block;
  font-family: var(--sans);
  font-size: 15px;
  font-weight: 600;
  padding: 13px 26px;
  border-radius: 999px;
  text-decoration: none;
  border: 1px solid transparent;
  transition: transform .12s, background .15s;
}

.btn:hover { transform: translateY(-1px); }
.btn:focus-visible { outline: 2px solid var(--coral); outline-offset: 3px; }

.btn-primary { background: var(--coral); color: #fff; }
.btn-primary:hover { background: var(--coral-deep); }

.btn-ghost { border-color: var(--dark-line); color: var(--on-dark); }
.btn-ghost:hover { background: var(--dark-2); }

.stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 1px;
  background: var(--dark-line);
  border: 1px solid var(--dark-line);
  max-width: 880px;
}

.stats div { background: var(--dark); padding: 18px 20px; }

.stats .n {
  font-family: var(--serif);
  font-size: 34px;
  line-height: 1;
  color: var(--coral);
  margin-bottom: 6px;
}

.stats .l {
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--on-dark-2);
}

/* ── Generic grids ───────────────────────────────────── */

.cols-2 { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 22px; }
.cols-3 { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 20px; }
.cols-4 { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 16px; }

.card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 24px;
}

.card p { font-size: 14.5px; color: var(--muted); margin: 0; }

.card .kicker {
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--coral);
  margin-bottom: 10px;
}

.band-dark .card { background: var(--dark-2); border-color: var(--dark-line); }
.band-dark .card h3 { color: var(--on-dark); }
.band-dark .card p { color: var(--on-dark-2); }

/* ── Skill cards ─────────────────────────────────────── */

.skill {
  background: var(--surface);
  border: 1px solid var(--line);
  border-top: 3px solid var(--coral);
  border-radius: 12px;
  padding: 22px;
}

.skill .count {
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 12px;
}

.skill h3 { font-family: var(--serif); font-size: 24px; font-weight: 500; margin-bottom: 8px; }

/* ── Module library ──────────────────────────────────── */

.filters { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 26px; }

.filters button {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  padding: 8px 15px;
  border-radius: 999px;
  border: 1px solid var(--line-2);
  background: transparent;
  color: var(--muted);
  cursor: pointer;
  transition: all .15s;
}

.filters button:hover { border-color: var(--coral); color: var(--coral); }
.filters button[aria-pressed="true"] { background: var(--coral); border-color: var(--coral); color: #fff; }
.filters button:focus-visible { outline: 2px solid var(--coral); outline-offset: 2px; }

.mods { display: grid; grid-template-columns: repeat(auto-fill, minmax(230px, 1fr)); gap: 12px; }

.mod {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 16px 18px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.mod[hidden] { display: none; }

.mod .tag {
  font-family: var(--mono);
  font-size: 9.5px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--coral);
}

.mod .nm { font-weight: 600; font-size: 15px; line-height: 1.25; }
.mod .ds { font-size: 13px; color: var(--muted); line-height: 1.45; }

/* ── Video slot ──────────────────────────────────────── */

.video {
  aspect-ratio: 16 / 9;
  max-width: 100%;
  border: 2px dashed var(--line-2);
  border-radius: 14px;
  background: var(--surface);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 12px;
  text-align: center;
  padding: 20px;
}

.video .play {
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: var(--coral-soft);
  display: flex;
  align-items: center;
  justify-content: center;
}

.video .play svg { width: 20px; height: 20px; }

.video .cap {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
}

/* ── Steps ───────────────────────────────────────────── */

.steps { display: grid; gap: 1px; background: var(--line); border: 1px solid var(--line); border-radius: 12px; overflow: hidden; }

.step { background: var(--surface); padding: 18px 22px; display: flex; gap: 16px; align-items: flex-start; }

.step .i {
  font-family: var(--mono);
  font-size: 11px;
  color: #fff;
  background: var(--coral);
  width: 22px; height: 22px;
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  flex: none;
  margin-top: 2px;
}

.step h3 { margin-bottom: 2px; }
.step p { font-size: 14px; color: var(--muted); margin: 0; }

/* ── Figure ──────────────────────────────────────────── */

figure { margin: 0 0 26px; }
figure svg { display: block; width: 100%; max-width: 100%; height: auto; }
figcaption { font-size: 13.5px; color: var(--muted); margin-top: 14px; max-width: 70ch; }

/* ── Review note (draft only) ────────────────────────── */

.review {
  border: 1px dashed var(--amber);
  background: var(--amber-soft);
  border-radius: 10px;
  padding: 14px 18px;
  margin: 22px 0;
  max-width: 78ch;
  font-size: 14px;
  color: #6b4410;
}

.review b {
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  display: block;
  margin-bottom: 5px;
}

.review p { color: inherit; max-width: none; margin: 0; }

/* ── Detail list ─────────────────────────────────────── */

.facts { display: grid; grid-template-columns: repeat(auto-fit, minmax(170px, 1fr)); gap: 1px; background: var(--line); border: 1px solid var(--line); border-radius: 12px; overflow: hidden; }
.facts div { background: var(--surface); padding: 16px 18px; }
.facts dt { font-family: var(--mono); font-size: 10px; letter-spacing: 0.09em; text-transform: uppercase; color: var(--muted); margin-bottom: 5px; }
.facts dd { margin: 0; font-size: 15px; font-weight: 600; }

.band-dark .facts { background: var(--dark-line); border-color: var(--dark-line); }
.band-dark .facts div { background: var(--dark-2); }
.band-dark .facts dd { color: var(--on-dark); }

/* ── Footer ──────────────────────────────────────────── */

footer { padding: 40px clamp(20px, 5vw, 72px); background: var(--dark); color: var(--on-dark-2); font-size: 13px; }
footer a { color: var(--coral); }

/* ── Mobile ──────────────────────────────────────────── */

@media (max-width: 880px) {
  :root { --rail: 0px; }
  .rail {
    position: static;
    width: auto;
    inset: auto;
    display: flex;
    gap: 2px;
    overflow-x: auto;
    padding: 10px;
    border-right: none;
    border-bottom: 1px solid var(--dark-line);
  }
  .rail-mark, .rail-sub { display: none; }
  .rail a { white-space: nowrap; border-left: none; border-bottom: 2px solid transparent; padding: 7px 12px; }
  .rail a.on { border-left: none; border-bottom-color: var(--coral); }
  .stage { margin-left: 0; }
  section { padding-block: 56px; }
  body { font-size: 15px; }
}