:root {
  --ink: #17212b;
  --ink-soft: #485b6a;
  --paper: #e8f0f5;
  --paper-deep: #d5e2eb;
  --line: #9db3c2;
  --purple: #703bd1;
  --purple-dark: #4c2498;
  --coral: #e95c5c;
  --teal: #159e96;
  --yellow: #f2c55a;
  --white: #ffffff;
  --display: "Arial Narrow", "Avenir Next Condensed", "Roboto Condensed", Arial, sans-serif;
  --body: "Avenir Next", "Segoe UI", Arial, sans-serif;
  --mono: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; color: var(--ink); background: var(--paper); font-family: var(--body); line-height: 1.6; overflow-x: hidden; }
a { color: var(--purple-dark); text-decoration-thickness: 0.1em; text-underline-offset: 0.16em; }
a:hover { color: var(--coral); }
a:focus-visible, button:focus-visible, input:focus-visible { outline: 3px solid var(--coral); outline-offset: 3px; }
.skip-link { position: absolute; left: -9999px; top: 0; z-index: 10; padding: 0.7rem 1rem; background: var(--ink); color: var(--white); }
.skip-link:focus { left: 1rem; top: 1rem; }
.site-header { position: sticky; top: 0; z-index: 5; border-bottom: 1px solid var(--line); background: rgba(232,240,245,0.95); backdrop-filter: blur(8px); }
.header-inner { max-width: 1240px; margin: 0 auto; padding: 0.8rem 1.5rem; display: flex; justify-content: space-between; align-items: center; gap: 1rem; }
.brand { display: inline-flex; align-items: center; gap: 0.55rem; color: var(--ink); text-decoration: none; font-family: var(--display); font-size: 0.9rem; font-weight: 800; letter-spacing: 0.1em; text-transform: uppercase; }
.brand-mark { width: 1rem; height: 1rem; border: 2px solid var(--purple); border-radius: 50%; position: relative; }
.brand-mark::after { content: ""; position: absolute; width: 0.35rem; height: 0.35rem; background: var(--coral); border-radius: 50%; top: 50%; left: 50%; transform: translate(-50%, -50%); }
.header-actions { display: flex; align-items: center; gap: 1rem; }
.text-nav { display: flex; gap: 1rem; font-family: var(--mono); font-size: 0.7rem; }
.text-nav a { color: var(--ink-soft); text-decoration: none; }
.lang-switch { display: inline-flex; overflow: hidden; border: 1px solid var(--ink); border-radius: 999px; font-family: var(--mono); font-size: 0.7rem; }
.lang-switch a { padding: 0.28rem 0.55rem; color: var(--ink); text-decoration: none; }
.lang-switch a[aria-current="page"] { background: var(--ink); color: var(--white); }
.wrap { max-width: 1240px; margin: 0 auto; padding: 0 1.5rem; }
.hero { padding: clamp(3.5rem, 8vw, 7rem) 0 3.5rem; border-bottom: 1px solid var(--line); }
.hero-grid { display: grid; grid-template-columns: minmax(0, 0.82fr) minmax(430px, 1.18fr); gap: clamp(2rem, 7vw, 8rem); align-items: start; }
.eyebrow { margin: 0 0 1rem; color: var(--purple-dark); font-family: var(--mono); font-size: 0.72rem; font-weight: 700; letter-spacing: 0.12em; text-transform: uppercase; }
h1, h2, h3 { font-family: var(--display); margin: 0; line-height: 0.96; letter-spacing: -0.045em; }
h1 { max-width: 7ch; font-size: clamp(4rem, 9vw, 8.6rem); font-weight: 900; text-transform: uppercase; }
.hero-lead { max-width: 34rem; margin: 1.5rem 0 0; color: var(--ink-soft); font-size: clamp(1.08rem, 1.7vw, 1.3rem); line-height: 1.45; }
.hero-answer { max-width: 34rem; margin-top: 2.2rem; padding: 0.3rem 0 0.3rem 1rem; border-left: 7px solid var(--coral); }
.hero-answer strong { display: block; font-family: var(--display); font-size: 1.35rem; line-height: 1.12; }
.hero-answer span { display: block; margin-top: 0.4rem; color: var(--ink-soft); font-size: 0.9rem; }
.instrument { position: relative; background: var(--white); border: 3px solid var(--purple); box-shadow: 14px 14px 0 var(--teal); }
.instrument::after { content: ""; position: absolute; right: 1rem; bottom: 1rem; width: 3rem; height: 3rem; border-right: 2px solid var(--coral); border-bottom: 2px solid var(--coral); pointer-events: none; }
.instrument-head { display: flex; justify-content: space-between; align-items: baseline; gap: 1rem; padding: 1.3rem 1.4rem 1rem; border-bottom: 1px solid var(--line); }
.instrument-kicker { color: var(--purple-dark); font-family: var(--mono); font-size: 0.68rem; font-weight: 700; letter-spacing: 0.12em; text-transform: uppercase; }
.instrument h2 { margin-top: 0.35rem; font-size: clamp(1.8rem, 3.4vw, 3rem); text-transform: uppercase; }
.instrument-code { color: var(--ink-soft); font-family: var(--mono); font-size: 0.7rem; }
.instrument-body { padding: 1.1rem 1.4rem 1.4rem; }
.route-display { display: grid; grid-template-columns: 1fr auto; align-items: end; gap: 1rem; min-height: 6.8rem; padding-bottom: 1rem; }
.route-display-label, .control-label { color: var(--ink-soft); font-family: var(--mono); font-size: 0.68rem; letter-spacing: 0.08em; text-transform: uppercase; }
.route-output { color: var(--purple-dark); font-family: var(--display); font-size: clamp(2.1rem, 5vw, 4.4rem); font-weight: 900; line-height: 0.9; }
.route-unit { display: block; margin-top: 0.45rem; color: var(--ink-soft); font-family: var(--mono); font-size: 0.68rem; text-align: right; }
.control { margin-top: 1.05rem; }
.control label { display: flex; justify-content: space-between; gap: 1rem; color: var(--ink); font-size: 0.9rem; }
.control output { color: var(--purple-dark); font-family: var(--mono); }
input[type="range"] { width: 100%; height: 1.3rem; margin: 0.25rem 0 0; accent-color: var(--coral); cursor: pointer; }
.instrument-foot { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; align-items: end; margin-top: 1.2rem; padding-top: 1rem; border-top: 1px solid var(--line); }
.share-output { color: var(--purple-dark); font-family: var(--display); font-size: 1.6rem; font-weight: 900; }
.phase-output { color: var(--teal); font-family: var(--display); font-size: 1.6rem; font-weight: 900; text-transform: uppercase; }
.simulate { grid-column: 1 / -1; min-height: 48px; border: 0; background: var(--purple); color: var(--white); padding: 0.7rem 1rem; font: inherit; font-weight: 800; cursor: pointer; }
.simulate:hover { background: var(--purple-dark); }
.instrument-note { margin: 1rem 0 0; color: var(--ink-soft); font-size: 0.84rem; }
.section { padding: clamp(4rem, 8vw, 8rem) 0; border-bottom: 1px solid var(--line); }
.section-grid { display: grid; grid-template-columns: 0.35fr minmax(0, 0.65fr); gap: clamp(2rem, 7vw, 8rem); }
.section-index { color: var(--purple-dark); font-family: var(--mono); font-size: 0.72rem; letter-spacing: 0.1em; }
.section-title { max-width: 11ch; margin-top: 0.6rem; font-size: clamp(2.8rem, 6vw, 5.5rem); text-transform: uppercase; }
.reading { max-width: 48rem; }
.reading > p { margin: 0 0 1.2rem; font-size: 1.08rem; }
.reading > p:first-child { font-size: clamp(1.3rem, 2.4vw, 1.75rem); line-height: 1.26; }
.reading strong { color: var(--purple-dark); }
.mechanism-figure { margin: 2rem 0 0; padding-top: 1rem; border-top: 1px solid var(--ink); }
.mechanism-figure canvas { display: block; width: 100%; height: auto; border: 1px solid var(--ink); background: var(--paper-deep); }
.figure-caption { margin: 0.7rem 0 0; color: var(--ink-soft); font-size: 0.85rem; }
.formula { margin: 2rem 0; padding: 1.25rem; background: var(--ink); color: var(--white); font-family: var(--mono); font-size: clamp(1.1rem, 2vw, 1.4rem); overflow-x: auto; }
.formula em { color: var(--yellow); font-family: Georgia, serif; }
.signal-table { width: 100%; margin: 2rem 0 0; border-collapse: collapse; border-top: 5px solid var(--purple); }
.signal-table th, .signal-table td { padding: 0.9rem 0.5rem; border-bottom: 1px solid var(--line); text-align: left; vertical-align: top; }
.signal-table th { color: var(--ink-soft); font-family: var(--mono); font-size: 0.68rem; letter-spacing: 0.08em; text-transform: uppercase; }
.signal-table td:first-child { font-family: var(--display); font-size: 1.2rem; font-weight: 800; text-transform: uppercase; }
.callout { margin-top: 2rem; padding: 1.15rem 1.2rem; border: 1px solid var(--ink); border-left: 7px solid var(--teal); background: rgba(255,255,255,0.45); }
.callout p { margin: 0; }
.step-list { margin: 2rem 0 0; padding: 0; list-style: none; counter-reset: steps; }
.step-list li { counter-increment: steps; display: grid; grid-template-columns: 2.5rem 1fr; gap: 0.8rem; padding: 1rem 0; border-top: 1px solid var(--line); }
.step-list li::before { content: counter(steps); width: 2rem; height: 2rem; display: grid; place-items: center; background: var(--purple); color: var(--white); border-radius: 50%; font-family: var(--mono); font-size: 0.8rem; }
.source-list { margin: 1.4rem 0 0; padding-left: 1.3rem; }
.source-list li { margin-bottom: 0.85rem; padding-left: 0.3rem; }
.method { color: var(--ink-soft); font-size: 0.92rem; }
.method p { margin: 0 0 1rem; }
.site-footer { padding: 2rem 0 3rem; }
.footer-inner { display: flex; justify-content: space-between; gap: 2rem; align-items: start; color: var(--ink-soft); font-size: 0.82rem; }
.footer-inner p { margin: 0; }
.footer-brand { color: var(--ink); font-family: var(--display); font-weight: 800; letter-spacing: 0.08em; text-transform: uppercase; }

@media (max-width: 820px) {
  .header-inner, .wrap { padding-inline: 1rem; }
  .text-nav { display: none; }
  .hero-grid, .section-grid { grid-template-columns: 1fr; }
  .hero { padding-top: 3.5rem; }
  h1 { max-width: 8ch; font-size: clamp(3.7rem, 17vw, 6.5rem); }
  .instrument { margin-right: 0.7rem; }
  .section-title { max-width: none; }
  .section-grid { gap: 1.7rem; }
}

@media (max-width: 520px) {
  .brand { font-size: 0.78rem; }
  .instrument-head { padding-inline: 1rem; }
  .instrument-body { padding-inline: 1rem; }
  .instrument-code { display: none; }
  .instrument-foot { grid-template-columns: 1fr; }
  .simulate { grid-column: auto; }
  .signal-table { font-size: 0.9rem; }
  .signal-table th, .signal-table td { padding-inline: 0.25rem; }
  .footer-inner { flex-direction: column; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: 0.01ms !important; animation-iteration-count: 1 !important; scroll-behavior: auto !important; transition-duration: 0.01ms !important; }
}