:root {
  --fog: #e8edf0;
  --paper: #f7f9fa;
  --ink: #0d1a2b;
  --ink-2: #1a2b42;
  --slate: #566678;
  --storm: #0e6b6b;
  --storm-soft: #cfe5e3;
  --amber: #f0a22e;
  --line: rgba(13, 26, 43, 0.14);
  --font-display: 'Bricolage Grotesque', 'Segoe UI', system-ui, sans-serif;
  --font-body: 'Instrument Sans', 'Segoe UI', system-ui, sans-serif;
  --font-mono: 'IBM Plex Mono', ui-monospace, Consolas, monospace;
  --gutter: clamp(16px, 4vw, 56px);
  --maxw: 1240px;
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--fog);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 1.0625rem;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}
img, svg { display: block; max-width: 100%; }
a { color: inherit; }
:focus-visible { outline: 3px solid var(--amber); outline-offset: 3px; border-radius: 4px; }
.skip { position: absolute; left: -999px; top: 8px; background: var(--ink); color: #fff; padding: 8px 14px; z-index: 100; }
.skip:focus { left: 8px; }
.sr-only { position: absolute; width: 1px; height: 1px; margin: -1px; padding: 0; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0; }

.wrap { width: min(100% - 2 * var(--gutter), var(--maxw)); margin-inline: auto; }
.mono { font-family: var(--font-mono); font-size: 0.78rem; letter-spacing: 0.04em; text-transform: uppercase; }

/* ---------- header ---------- */
.site-head {
  position: fixed; inset: 0 0 auto 0; z-index: 50;
  backdrop-filter: blur(14px);
  background: color-mix(in srgb, var(--fog) 82%, transparent);
  border-bottom: 1px solid var(--line);
}
.site-head .wrap { display: flex; align-items: center; gap: 20px; height: 64px; }
.brand { display: flex; align-items: center; gap: 10px; text-decoration: none; font-family: var(--font-display); font-weight: 700; font-size: 1.15rem; letter-spacing: -0.01em; }
.brand svg { width: 28px; height: 28px; }
.nav { margin-left: auto; display: flex; align-items: center; gap: clamp(12px, 2vw, 28px); }
.nav a { text-decoration: none; font-size: 0.95rem; color: var(--ink-2); }
.nav a:hover { color: var(--storm); }
.nav a.btn { color: #fff; }
.nav a.btn:hover { color: #fff; }
.lang { position: relative; }
.lang select {
  appearance: none; background: transparent; border: 1px solid var(--line); border-radius: 999px;
  padding: 6px 28px 6px 12px; font: inherit; font-size: 0.85rem; color: var(--ink); cursor: pointer;
  background-image: linear-gradient(45deg, transparent 50%, var(--ink) 50%), linear-gradient(135deg, var(--ink) 50%, transparent 50%);
  background-position: calc(100% - 15px) 52%, calc(100% - 10px) 52%; background-size: 5px 5px; background-repeat: no-repeat;
}
.btn {
  display: inline-flex; align-items: center; gap: 10px; padding: 14px 24px; border-radius: 999px;
  background: var(--ink); color: #fff; text-decoration: none; font-weight: 600; font-size: 1rem;
  border: 1px solid var(--ink); transition: transform .2s ease, background .2s ease, color .2s ease;
}
.btn:hover { background: var(--storm); border-color: var(--storm); transform: translateY(-2px); }
.btn.ghost { background: transparent; color: var(--ink); }
.btn.ghost:hover { background: var(--ink); color: #fff; border-color: var(--ink); }
.btn.sm { padding: 9px 16px; font-size: 0.9rem; }
.btn .arrow { transition: transform .2s ease; }
.btn:hover .arrow { transform: translateX(4px); }

/* ---------- hero ---------- */
.hero { position: relative; min-height: 100svh; display: grid; align-items: center; padding: 112px 0 72px; overflow: hidden; }
.isobars { position: absolute; inset: 0; width: 100%; height: 100%; pointer-events: none; }
.isobars path { fill: none; stroke: var(--storm); stroke-width: 1.2; opacity: .5; vector-effect: non-scaling-stroke; }
.isobars path.key { stroke: var(--amber); stroke-width: 2; opacity: .95; }
.hero-inner { position: relative; display: grid; gap: 28px; max-width: 880px; }
.eyebrow { display: inline-flex; align-items: center; gap: 10px; color: var(--storm); }
.eyebrow::before { content: ''; width: 28px; height: 1px; background: currentColor; }
h1, h2, h3 { font-family: var(--font-display); font-weight: 700; letter-spacing: -0.025em; line-height: 1.02; margin: 0; }
h1 { font-size: clamp(2.8rem, 8.2vw, 6.6rem); font-variation-settings: 'wdth' 90; }
h1 .line { display: block; overflow: hidden; padding-bottom: .06em; }
h1 .line span { display: inline-block; will-change: transform; }
h1 em { font-style: normal; color: var(--storm); }
.lede { font-size: clamp(1.1rem, 1.6vw, 1.3rem); color: var(--ink-2); max-width: 58ch; margin: 0; }
.cta-row { display: flex; flex-wrap: wrap; gap: 14px; align-items: center; }
.readout {
  position: absolute; right: var(--gutter); bottom: 40px; display: grid; gap: 6px; padding: 14px 16px;
  background: var(--paper); border: 1px solid var(--line); border-radius: 10px; min-width: 210px; color: var(--ink-2);
}
.readout b { font-family: var(--font-mono); font-weight: 500; color: var(--storm); }
.readout .row { display: flex; justify-content: space-between; gap: 20px; }

/* ---------- sections ---------- */
section { position: relative; }
.pad { padding: clamp(72px, 11vw, 160px) 0; }
.sec-head { display: grid; gap: 18px; margin-bottom: clamp(36px, 6vw, 72px); max-width: 780px; }
h2 { font-size: clamp(2rem, 5vw, 3.8rem); }
.sec-head p { margin: 0; color: var(--slate); font-size: 1.15rem; max-width: 60ch; }

/* instruments */
.instruments { display: grid; gap: clamp(18px, 2.4vw, 32px); grid-template-columns: repeat(2, 1fr); }
.panel {
  position: relative; background: var(--paper); border: 1px solid var(--line); border-radius: 20px;
  padding: clamp(24px, 3vw, 44px); display: grid; gap: 22px; align-content: start; overflow: hidden;
}
.panel.dark { background: var(--ink); color: #eaf1f4; border-color: var(--ink); }
.panel.dark .slate, .panel.dark li { color: #b6c4cf; }
.panel-top { display: flex; justify-content: space-between; align-items: center; color: var(--storm); }
.panel.dark .panel-top { color: var(--amber); }
.panel h3 { font-size: clamp(2rem, 3.6vw, 3rem); }
.panel .tag { font-size: 1.15rem; margin: 0; color: var(--ink-2); }
.panel.dark .tag { color: #dbe6ec; }
.chart { width: 100%; height: 120px; }
.chart .grid { stroke: var(--line); stroke-width: 1; }
.panel.dark .chart .grid { stroke: rgba(255,255,255,.14); }
.chart .trace { fill: none; stroke: var(--storm); stroke-width: 2.5; stroke-linecap: round; stroke-linejoin: round; }
.panel.dark .chart .trace { stroke: var(--amber); }
.chart .dot { fill: var(--amber); }
.panel.dark .chart .dot { fill: #fff; }
.panel ul { list-style: none; margin: 0; padding: 0; display: grid; gap: 10px; }
.panel li { padding-left: 22px; position: relative; color: var(--ink-2); }
.panel li::before { content: ''; position: absolute; left: 0; top: .72em; width: 10px; height: 2px; background: var(--amber); }
.panel .cta-row { margin-top: 6px; }
.panel.dark .btn { background: var(--amber); color: var(--ink); border-color: var(--amber); }
.panel.dark .btn:hover { background: #fff; border-color: #fff; }

/* method */
.method { background: var(--paper); border-block: 1px solid var(--line); }
.method-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: clamp(20px, 3vw, 48px); }
.method-grid article { border-top: 2px solid var(--ink); padding-top: 18px; display: grid; gap: 10px; align-content: start; }
.method-grid h3 { font-size: 1.5rem; letter-spacing: -0.01em; }
.method-grid p { margin: 0; color: var(--slate); }

/* stations / facts */
.facts { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1px; background: var(--line); border: 1px solid var(--line); border-radius: 16px; overflow: hidden; }
.facts div { background: var(--fog); padding: 28px 22px; display: grid; gap: 6px; }
.facts b { font-family: var(--font-display); font-size: clamp(2rem, 4vw, 3rem); letter-spacing: -0.03em; }
.facts span { color: var(--slate); font-size: 0.95rem; }

/* contact */
.closing { background: var(--ink); color: #eaf1f4; }
.closing h2 { max-width: 16ch; }
.closing p { color: #b6c4cf; max-width: 56ch; }
.closing .btn { background: var(--amber); border-color: var(--amber); color: var(--ink); }
.closing .btn:hover { background: #fff; border-color: #fff; }
.closing .btn.ghost { background: transparent; color: #fff; border-color: rgba(255,255,255,.4); }
.closing .btn.ghost:hover { background: #fff; color: var(--ink); }

footer { background: var(--ink); color: #9fb0bd; padding: 32px 0 44px; border-top: 1px solid rgba(255,255,255,.1); font-size: 0.92rem; }
footer .wrap { display: flex; flex-wrap: wrap; gap: 14px 32px; align-items: center; justify-content: space-between; }
footer nav { display: flex; flex-wrap: wrap; gap: 8px 22px; }
footer a { color: #dbe6ec; }
footer a:hover { color: var(--amber); }

/* reveal start state only when JS + motion are available */
.js-motion [data-reveal] { opacity: 0; transform: translateY(28px); }

@media (max-width: 900px) {
  .instruments, .method-grid { grid-template-columns: 1fr; }
  .facts { grid-template-columns: repeat(2, 1fr); }
  .readout { position: relative; right: auto; bottom: auto; margin-top: 36px; justify-self: start; }
  .nav .hide-sm { display: none; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .js-motion [data-reveal] { opacity: 1; transform: none; }
  .btn, .btn .arrow { transition: none; }
}

@media (max-width: 900px) {
  .readout { margin: 36px var(--gutter) 0; }
  .isobars path { opacity: 0.28; }
  .isobars path.key { opacity: 0.6; }
}
@media (max-width: 560px) {
  .brand span { display: none; }
  .site-head .wrap { gap: 10px; }
  .nav { gap: 10px; }
  .btn.sm { padding: 8px 14px; white-space: nowrap; font-size: 0.85rem; }
  .btn { white-space: nowrap; }
  .cta-row .btn { width: 100%; justify-content: space-between; }
}