/* LOCKED 2026-08-16 — Instrument. design-system/LOCKED.md */
:root {
  --font-display: "Avenir Next Condensed", "Helvetica Neue", "Arial Narrow", sans-serif;
  --font-text: "Avenir Next", "Helvetica Neue", system-ui, sans-serif;
  --font-mono: "SF Mono", Menlo, ui-monospace, monospace;
  --bg: #07080a;
  --paper: #0c0e12;
  --elev: #12151b;
  --ink: #e6eaee;
  --mute: #6d7680;
  --line: rgb(200 220 235 / 0.1);
  --accent: #8be0c8;
  --on-accent: #07110e;
  --danger: #ff5c5c;
  --gutter: clamp(1rem, 2.4vw, 2rem);
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: 4.25rem;
}

body {
  margin: 0;
  min-height: 100vh;
  font: 16px/1.5 var(--font-text);
  background: var(--bg);
  color: var(--ink);
  color-scheme: dark;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  background-image:
    linear-gradient(var(--line) 1px, transparent 1px),
    linear-gradient(90deg, var(--line) 1px, transparent 1px);
  background-size: 64px 64px;
  mask-image: linear-gradient(180deg, rgb(0 0 0 / 0.5), transparent 38%);
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; text-underline-offset: 0.18em; }
code { font-family: var(--font-mono); font-size: 0.86em; color: var(--accent); }

.skip {
  position: absolute;
  left: -999px;
  top: 0;
  background: var(--accent);
  color: var(--on-accent);
  padding: 0.4rem 0.7rem;
}
.skip:focus { left: 0.5rem; top: 0.5rem; z-index: 20; }

.top {
  position: sticky;
  top: 0;
  z-index: 12;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.8rem;
  padding: 0.65rem var(--gutter);
  background: rgb(7 8 10 / 0.92);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(10px);
}

.brand {
  font-family: var(--font-display);
  letter-spacing: 0.18em;
  font-size: 0.92rem;
  color: var(--ink);
  text-decoration: none;
  flex: 0 0 auto;
}

.nav {
  display: flex;
  flex-wrap: nowrap;
  justify-content: flex-end;
  gap: 0.25rem 1rem;
  font-size: 0.86rem;
  max-width: min(70vw, 42rem);
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: none;
}
.nav::-webkit-scrollbar { display: none; }
.nav a { color: var(--mute); white-space: nowrap; }
.nav a:hover { color: var(--accent); text-decoration: none; }

.wrap {
  position: relative;
  z-index: 1;
  padding: 0 var(--gutter) 4.5rem;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 1.5rem 2.5rem;
  align-items: end;
  padding: 2.4rem 0 2rem;
}

.kicker {
  margin: 0 0 0.65rem;
  color: var(--accent);
  font-size: 0.72rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

h1 {
  margin: 0 0 0.7rem;
  font-family: var(--font-display);
  font-weight: 500;
  font-size: clamp(3rem, 8vw, 6.4rem);
  letter-spacing: 0.14em;
  line-height: 0.9;
}

.lede {
  margin: 0 0 0.7rem;
  max-width: 42rem;
  font-size: 1.18rem;
  color: var(--ink);
}
.sub {
  margin: 0 0 1.2rem;
  max-width: 42rem;
  color: var(--mute);
  font-size: 1.02rem;
  line-height: 1.55;
}
.status {
  margin: 0.9rem 0 0;
  color: var(--mute);
  font-size: 0.88rem;
}

.actions { display: flex; flex-wrap: wrap; gap: 0.5rem; }

.btn {
  display: inline-block;
  padding: 0.7rem 1rem;
  border: 1px solid var(--line);
  background: var(--elev);
  color: var(--ink);
  font: 0.82rem/1.1 var(--font-text);
  letter-spacing: 0.01em;
  text-decoration: none;
  min-height: 2.6rem;
}
.btn:hover { border-color: var(--accent); color: var(--accent); text-decoration: none; }
.btn.primary { background: var(--accent); color: var(--on-accent); border-color: var(--accent); }
.btn.primary:hover { filter: brightness(1.06); color: var(--on-accent); }

.seal {
  width: min(9.5rem, 32vw);
  color: var(--accent);
  opacity: 0;
  animation: on 0.2s ease forwards;
}

.meta {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  border: 1px solid var(--line);
  opacity: 0;
  animation: on 0.2s ease 0.2s forwards;
}
.meta div {
  padding: 0.8rem 1rem;
  border-right: 1px solid var(--line);
}
.meta div:last-child { border-right: 0; }
.meta dt {
  margin: 0 0 0.2rem;
  color: var(--mute);
  font-size: 0.68rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}
.meta dd { margin: 0; font-family: var(--font-mono); font-size: 0.86rem; }

.board {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-top: 0;
}
.board article {
  background: var(--paper);
  padding: 1rem 1.05rem;
}
.board h3 {
  margin: 0 0 0.4rem;
  font-family: var(--font-text);
  font-size: 0.95rem;
  font-weight: 600;
  letter-spacing: 0;
  text-transform: none;
  color: var(--accent);
}
.board p { margin: 0; font-size: 1rem; line-height: 1.45; }

@keyframes on {
  from { opacity: 0; }
  to { opacity: 1; }
}

section,
#brief { scroll-margin-top: 4.25rem; }
section { padding: 2.4rem 0; border-bottom: 1px solid var(--line); }

.idx {
  display: flex;
  align-items: baseline;
  gap: 0.75rem;
  margin: 0 0 0.85rem;
}
.idx b {
  font-family: var(--font-mono);
  font-weight: 400;
  color: var(--accent);
  font-size: 0.78rem;
}
.idx h2 {
  margin: 0;
  font-family: var(--font-text);
  font-weight: 600;
  letter-spacing: 0;
  text-transform: none;
  font-size: 1.22rem;
}

.note {
  margin: 0 0 0.9rem;
  color: var(--mute);
  font-size: 0.98rem;
  max-width: 52rem;
  line-height: 1.5;
}
.note.after { margin: 0.9rem 0 0; }
.note.swipe { display: none; }

.scroll { overflow-x: auto; }

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.ledger {
  width: 100%;
  min-width: 52rem;
  border-collapse: collapse;
  font-size: 0.92rem;
}
.ledger.compact { min-width: 28rem; }
.ledger th,
.ledger td {
  text-align: left;
  vertical-align: top;
  padding: 0.5rem 0.55rem;
  border-bottom: 1px solid var(--line);
  background: var(--bg);
}
.ledger th {
  color: var(--mute);
  font-weight: 500;
  font-size: 0.68rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}
.ledger th:first-child,
.ledger td:first-child {
  position: sticky;
  left: 0;
  z-index: 1;
  min-width: 13rem;
  font-weight: 500;
  box-shadow: 1px 0 0 var(--line);
}
.ledger tbody th {
  text-transform: none;
  letter-spacing: 0;
  font-size: 0.92rem;
  color: var(--ink);
}
.ledger tbody tr:hover th,
.ledger tbody tr:hover td { background: var(--elev); }
.ledger tr.mark td { background: var(--paper); }
.ledger tr.mark:hover td { background: var(--elev); }

.flag {
  display: inline-block;
  min-width: 2.4rem;
  margin-right: 0.4rem;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.08em;
  color: var(--mute);
}
.ok .flag { color: var(--accent); }
.hot .flag { color: var(--danger); }

.grid3,
.grid2 {
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}
.grid3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.cell {
  background: var(--paper);
  padding: 0.95rem 1rem;
}
.cell:hover { background: var(--elev); }
.cell h3 {
  margin: 0 0 0.4rem;
  font-family: var(--font-text);
  font-size: 1rem;
  letter-spacing: 0;
  text-transform: none;
  font-weight: 600;
}
.cell p { margin: 0; color: var(--ink); font-size: 0.98rem; line-height: 1.5; }
.cell p span { color: var(--mute); }

.math {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  margin: 0 0 1.2rem;
}
.math > div {
  background: var(--paper);
  padding: 1.1rem 1.15rem;
}
.math .figure {
  margin: 0.15rem 0 0.35rem;
  font-family: var(--font-display);
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  letter-spacing: 0.04em;
  line-height: 1;
}
.math .figure span {
  display: inline-block;
  margin-left: 0.25rem;
  font-family: var(--font-text);
  font-size: 0.92rem;
  letter-spacing: 0;
  color: var(--mute);
}
.math .figure-sub,
.math .figure-copy {
  margin: 0;
  color: var(--mute);
  font-size: 0.92rem;
  line-height: 1.45;
}
.math .figure-copy { color: var(--ink); }

.ask {
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) auto;
  gap: 1.2rem;
  align-items: end;
  margin-top: 1.2rem;
  padding: 1.15rem 1.2rem;
  border: 1px solid var(--line);
  background: var(--paper);
}
.ask h3 {
  margin: 0 0 0.35rem;
  font-size: 1rem;
  font-weight: 600;
}
.ask p { margin: 0; max-width: 42rem; font-size: 0.98rem; line-height: 1.5; }

.stack { display: grid; }
.row {
  display: grid;
  grid-template-columns: 8rem 1fr;
  gap: 1rem;
  padding: 0.65rem 0.2rem;
  border-bottom: 1px solid var(--line);
}
.row:hover { background: var(--elev); }
.row strong {
  font-family: var(--font-display);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  font-weight: 500;
  font-size: 0.82rem;
}
.row p { margin: 0; color: var(--ink); }

.foot {
  padding: 1.6rem 0 0;
  color: var(--mute);
  font-size: 0.82rem;
}
.foot nav { display: flex; flex-wrap: wrap; gap: 0.85rem; margin-top: 0.55rem; }

@media (max-width: 880px) {
  .hero { grid-template-columns: 1fr; padding-top: 1.6rem; }
  .seal { width: 6.5rem; }
  .meta, .grid3, .grid2, .board, .math { grid-template-columns: 1fr 1fr; }
  .ask { grid-template-columns: 1fr; }
  .row { grid-template-columns: 1fr; gap: 0.2rem; }
  .note.swipe { display: block; }
}

@media (max-width: 720px) {
  .ledger.compare { min-width: 0; }
  .ledger.compare thead { display: none; }
  .ledger.compare,
  .ledger.compare tbody,
  .ledger.compare tr,
  .ledger.compare th,
  .ledger.compare td {
    display: block;
    width: 100%;
  }
  .ledger.compare th:first-child,
  .ledger.compare td:first-child {
    position: static;
    min-width: 0;
    box-shadow: none;
  }
  .ledger.compare tbody th {
    padding: 1.05rem 0.15rem 0.3rem;
    border-bottom: 0;
    color: var(--accent);
    font-size: 1rem;
  }
  .ledger.compare td {
    display: grid;
    grid-template-columns: 8.4rem minmax(0, 1fr);
    gap: 0.55rem;
    align-items: start;
    padding: 0.38rem 0.15rem;
  }
  .ledger.compare td::before {
    content: attr(data-col);
    color: var(--mute);
    font-size: 0.78rem;
    font-weight: 500;
  }
  .ledger.compare tr.mark td { background: transparent; }
  .ledger.compare tbody tr:hover th,
  .ledger.compare tbody tr:hover td { background: transparent; }
}

@media (max-width: 560px) {
  .meta, .grid3, .grid2, .board, .math { grid-template-columns: 1fr; }
  .nav { gap: 0.15rem 0.85rem; max-width: 68vw; }
  h1 {
    font-size: clamp(2.4rem, 15vw, 3.4rem);
    letter-spacing: 0.1em;
  }
  .hero { padding: 1.15rem 0 1.2rem; }
  .seal { display: none; }
  .lede { font-size: 1.08rem; }
}

@media (prefers-reduced-motion: reduce) {
  .seal, .meta { animation: none; opacity: 1; }
}