:root {
  --blue: #1768ff;
  --blue-dark: #0c46b5;
  --orange: #ff5b35;
  --lime: #d9ff57;
  --ink: #071b2b;
  --paper: #fff8e7;
  --muted: #49606c;
  --line: rgba(7, 27, 43, 0.25);
  --display: "Arial Narrow", "Helvetica Neue", Arial, sans-serif;
  --body: "Helvetica Neue", Arial, sans-serif;
  --mono: ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;
  color-scheme: light;
  font-synthesis: none;
}

* { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  background: var(--paper);
}

body {
  margin: 0;
  overflow-x: hidden;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--body);
  font-size: 1rem;
  line-height: 1.56;
  text-rendering: optimizeLegibility;
}

a { color: inherit; text-underline-offset: 0.18em; }

button,
input { font: inherit; }

button,
a { -webkit-tap-highlight-color: transparent; }

:focus-visible {
  outline: 3px solid var(--lime);
  outline-offset: 4px;
}

.skip-link {
  position: fixed;
  z-index: 100;
  top: 0.75rem;
  left: 0.75rem;
  padding: 0.75rem 1rem;
  transform: translateY(-160%);
  background: var(--ink);
  color: var(--paper);
}

.skip-link:focus { transform: none; }

.sr-only {
  position: absolute !important;
  width: 1px !important;
  min-width: 1px !important;
  max-width: 1px !important;
  height: 1px !important;
  padding: 0 !important;
  margin: -1px !important;
  overflow: hidden !important;
  clip: rect(0, 0, 0, 0) !important;
  white-space: nowrap !important;
  border: 0 !important;
}

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 4.5rem;
  padding: 0.65rem max(1rem, calc((100vw - 1240px) / 2));
  border-bottom: 1px solid rgba(255, 255, 255, 0.35);
  background: var(--blue);
  color: var(--paper);
}

.brand {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  gap: 0.65rem;
  font-family: var(--mono);
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.14em;
  text-decoration: none;
  text-transform: uppercase;
}

.brand > span {
  width: 1.5rem;
  height: 0.32rem;
  background: linear-gradient(90deg, var(--lime) 0 58%, var(--orange) 58%);
}

.language-nav {
  display: flex;
  gap: 0.4rem;
  font-family: var(--mono);
  font-size: 0.72rem;
  font-weight: 800;
}

.language-nav a,
.language-nav > span {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 44px;
  min-height: 44px;
  border: 1px solid rgba(255, 255, 255, 0.55);
  text-decoration: none;
}

.language-nav [aria-current="page"] {
  background: var(--lime);
  border-color: var(--lime);
  color: var(--ink);
}

.hero {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  grid-template-areas:
    "eyebrow eyebrow eyebrow eyebrow eyebrow eyebrow . . number number number number"
    "title title title title title title title . number number number number"
    "deck deck deck deck deck deck . . number number number number"
    "trust trust trust trust trust trust trust trust trust trust trust trust";
  gap: 1.5rem 1rem;
  min-height: calc(100svh - 4.5rem);
  padding: clamp(3rem, 8vw, 7.5rem) max(1rem, calc((100vw - 1240px) / 2)) 2.2rem;
  background: var(--blue);
  color: var(--paper);
}

.hero__copy { display: contents; }

.hero .eyebrow { grid-area: eyebrow; }
.hero h1 { grid-area: title; }
.hero .deck { grid-area: deck; }
.hero .trust { grid-area: trust; }

.eyebrow {
  margin: 0 0 0.65rem;
  font-family: var(--mono);
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

h1,
h2 {
  margin: 0;
  font-family: var(--display);
  font-stretch: condensed;
  font-weight: 900;
  letter-spacing: -0.06em;
  line-height: 0.91;
}

h1 { font-size: clamp(4.5rem, 9.5vw, 9.2rem); }
h2 { font-size: clamp(3.1rem, 6vw, 6.5rem); }

.deck {
  max-width: 45rem;
  margin: 1rem 0 0;
  font-size: clamp(1.2rem, 2vw, 1.55rem);
  line-height: 1.36;
}

.deck strong {
  color: var(--lime);
  font-weight: 800;
}

.hero__number {
  grid-area: number;
  align-self: center;
  padding: 1rem 0 1.25rem;
  border-top: 0.55rem solid var(--lime);
  border-bottom: 1px solid rgba(255, 255, 255, 0.4);
}

.hero__number strong,
.hero__number span,
.hero__number small { display: block; }

.hero__number strong {
  color: var(--lime);
  font-family: var(--display);
  font-size: clamp(6rem, 13vw, 12rem);
  font-weight: 900;
  letter-spacing: -0.09em;
  line-height: 0.78;
}

.hero__number span {
  margin-top: 1rem;
  font-family: var(--display);
  font-size: clamp(2rem, 4vw, 3.7rem);
  font-weight: 900;
  letter-spacing: -0.04em;
}

.hero__number small {
  margin-top: 0.4rem;
  font-family: var(--mono);
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.trust {
  display: flex;
  flex-wrap: wrap;
  align-self: end;
  gap: 0.4rem 1.25rem;
  margin: 1.5rem 0 0;
  padding-top: 1rem;
  border-top: 1px solid rgba(255, 255, 255, 0.35);
  font-family: var(--mono);
  font-size: 0.72rem;
}

.trust > span {
  font-weight: 900;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.lab {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  min-height: 100svh;
  background: var(--paper);
}

.lab__stage {
  position: sticky;
  top: 0;
  display: flex;
  flex-direction: column;
  min-height: 100svh;
  padding: 1.25rem clamp(1rem, 4vw, 4rem) 1.5rem;
  background: var(--ink);
  color: var(--paper);
}

.stage-heading {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  font-family: var(--mono);
  font-size: 0.7rem;
  font-weight: 800;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.slinky {
  display: block;
  width: min(100%, 31rem);
  height: min(68svh, 42rem);
  margin: auto;
  overflow: visible;
}

.hanger,
.floor { stroke: rgba(255, 248, 231, 0.62); stroke-width: 3; }
.guide { stroke: rgba(255, 248, 231, 0.2); stroke-dasharray: 4 7; }

.coils {
  fill: none;
  stroke: var(--lime);
  stroke-linecap: round;
  stroke-width: 7;
}

.marker { stroke: var(--ink); stroke-width: 3; }
.marker--top { fill: var(--orange); }
.marker--front { fill: var(--lime); }
.marker--com { fill: var(--blue); stroke: var(--paper); }
.marker--bottom { fill: var(--paper); }

.svg-label {
  fill: var(--paper);
  font-family: var(--mono);
  font-size: 13px;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.readouts {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1px;
  background: rgba(255, 255, 255, 0.25);
}

.readouts p {
  margin: 0;
  padding: 0.75rem 0.85rem;
  background: var(--ink);
}

.readouts span,
.readouts strong { display: block; }
.readouts span { font-family: var(--mono); font-size: 0.68rem; text-transform: uppercase; }
.readouts strong { color: var(--lime); font-family: var(--display); font-size: 2rem; line-height: 1; }

.lab__controls {
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: clamp(3rem, 8vw, 8rem) clamp(1.25rem, 6vw, 6rem);
}

.lab__controls > p:not(.eyebrow, .lab__note, .no-js-note) {
  max-width: 37rem;
  font-size: 1.2rem;
}

.time-control {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  margin-top: 2.5rem;
  font-family: var(--mono);
  font-size: 0.78rem;
  font-weight: 800;
  text-transform: uppercase;
}

input[type="range"] {
  width: 100%;
  min-height: 44px;
  margin: 0.6rem 0 0;
  accent-color: var(--orange);
  cursor: ew-resize;
}

.scale {
  display: flex;
  justify-content: space-between;
  font-family: var(--mono);
  font-size: 0.68rem;
}

.drop-button {
  min-height: 54px;
  margin-top: 1.75rem;
  padding: 0.8rem 1rem;
  border: 2px solid var(--ink);
  border-radius: 0;
  background: var(--orange);
  box-shadow: 0.45rem 0.45rem 0 var(--ink);
  color: var(--ink);
  font-family: var(--mono);
  font-size: 0.8rem;
  font-weight: 900;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  cursor: pointer;
}

.drop-button:active { transform: translate(0.2rem, 0.2rem); box-shadow: 0.25rem 0.25rem 0 var(--ink); }

.lab__note,
.no-js-note {
  margin-top: 1.5rem;
  color: var(--muted);
  font-size: 0.82rem;
}

.js .no-js-note { display: none; }

.story > section {
  padding: clamp(4.5rem, 10vw, 10rem) max(1rem, calc((100vw - 1080px) / 2));
}

.story h2 { max-width: 61rem; }

.proof__lines {
  margin-top: 4rem;
  border-top: 4px solid var(--ink);
}

.proof__lines p {
  display: grid;
  grid-template-columns: 9rem minmax(15rem, 1fr) minmax(18rem, 1.35fr);
  gap: 1.4rem;
  margin: 0;
  padding: 1.4rem 0;
  border-bottom: 1px solid var(--line);
}

.proof__lines span { font-family: var(--mono); font-size: 0.72rem; font-weight: 900; text-transform: uppercase; }
.proof__lines strong { font-size: 1.1rem; line-height: 1.35; }

.big-result {
  display: grid;
  grid-template-columns: auto minmax(12rem, 24rem);
  align-items: end;
  gap: 1.5rem;
  margin: 5rem 0 0;
  padding-top: 1rem;
  border-top: 0.55rem solid var(--blue);
}

.big-result strong {
  color: var(--blue);
  font-family: var(--display);
  font-size: clamp(5rem, 14vw, 10rem);
  font-weight: 900;
  letter-spacing: -0.08em;
  line-height: 0.8;
}

.big-result span { font-size: 1.1rem; font-weight: 800; }

.force {
  background: var(--orange);
}

.force > p:not(.eyebrow) {
  max-width: 47rem;
  font-size: clamp(1.2rem, 2.2vw, 1.55rem);
}

.force-line {
  display: grid;
  grid-template-columns: 1fr auto 1fr auto 1fr;
  align-items: center;
  gap: 1rem;
  max-width: 58rem;
  margin: 4rem 0;
  padding: 1.4rem 0;
  border-top: 4px solid var(--ink);
  border-bottom: 4px solid var(--ink);
  text-align: center;
  font-family: var(--mono);
  font-size: 0.75rem;
  font-weight: 900;
  text-transform: uppercase;
}

.force-line i { font-family: var(--display); font-size: 4rem; font-style: normal; line-height: 1; }
.force-line b { padding: 0.6rem; background: var(--ink); color: var(--lime); }

.specimens {
  background: var(--blue);
  color: var(--paper);
}

.specimens > p:not(.eyebrow) { max-width: 48rem; font-size: 1.2rem; }

.table-wrap {
  margin-top: 3.5rem;
  overflow-x: auto;
  border-top: 0.55rem solid var(--lime);
}

table {
  width: 100%;
  min-width: 37rem;
  border-collapse: collapse;
  font-variant-numeric: tabular-nums;
}

caption {
  padding: 1rem 0;
  text-align: left;
  font-family: var(--mono);
  font-size: 0.72rem;
  font-weight: 900;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

th,
td {
  padding: 1rem 0.8rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.35);
  text-align: left;
}

thead th { color: var(--lime); font-family: var(--mono); font-size: 0.75rem; text-transform: uppercase; }
tbody th { font-weight: 700; }
td { font-family: var(--mono); }

.method > p:not(.eyebrow) {
  max-width: 48rem;
  font-size: 1.16rem;
}

.sources {
  display: grid;
  grid-template-columns: 1fr 1fr;
  margin-top: 4rem;
  border-top: 4px solid var(--ink);
}

.sources a {
  min-height: 8rem;
  padding: 1.25rem;
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  text-decoration: none;
}

.sources a:hover { background: var(--lime); }
.sources strong,
.sources span { display: block; }
.sources strong { font-family: var(--mono); font-size: 0.8rem; }
.sources span { margin-top: 0.8rem; }

footer {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  padding: 1.5rem max(1rem, calc((100vw - 1080px) / 2));
  background: var(--ink);
  color: var(--paper);
  font-family: var(--mono);
  font-size: 0.72rem;
}

footer p { margin: 0; }

.back-to-top {
  position: fixed;
  z-index: 30;
  right: 1rem;
  bottom: 1rem;
  width: 48px;
  height: 48px;
  border: 0;
  border-radius: 0;
  opacity: 0;
  transform: translateY(5rem);
  background: var(--lime);
  color: var(--ink);
  font-weight: 900;
  pointer-events: none;
  transition: opacity 160ms ease, transform 160ms ease;
}

.back-to-top.is-visible { opacity: 1; transform: none; pointer-events: auto; }

.error-page {
  min-height: 100svh;
  padding: clamp(2rem, 8vw, 7rem);
  background: var(--blue);
  color: var(--paper);
}

.error-page main { max-width: 55rem; }
.error-page h1 { margin: 1rem 0 2rem; }
.error-page p { max-width: 37rem; font-size: 1.2rem; }
.error-page a { display: inline-flex; align-items: center; min-height: 44px; color: var(--lime); font-weight: 800; }

@media (max-width: 820px) {
  .hero {
    grid-template-columns: 1fr;
    grid-template-areas: "eyebrow" "title" "number" "deck" "trust";
    min-height: auto;
    padding-top: 2.5rem;
  }

  h1 { font-size: clamp(3.7rem, 16.5vw, 5.2rem); }
  h2 { font-size: clamp(3rem, 13vw, 4.5rem); }

  .hero__number {
    display: grid;
    grid-template-columns: auto 1fr;
    align-items: end;
    gap: 0 0.8rem;
    margin-top: 0.5rem;
  }

  .hero__number strong { font-size: clamp(5.5rem, 27vw, 8rem); }
  .hero__number span { margin: 0 0 0.5rem; font-size: 2rem; }
  .hero__number small { grid-column: 1 / -1; }

  .trust { display: grid; gap: 0.5rem; }

  .lab { display: block; }
  .lab__stage { position: relative; min-height: min(44rem, 100svh); }
  .slinky { height: min(65svh, 35rem); }

  .proof__lines p {
    display: grid;
    grid-template-columns: 7rem 1fr;
  }

  .proof__lines p:not(:first-child) { margin-top: 0; }
  .proof__lines p > :last-child { grid-column: 1 / -1; }
  .big-result { grid-template-columns: 1fr; }
  .force-line { grid-template-columns: 1fr auto 1fr; }
  .force-line b { grid-column: 1 / -1; grid-row: 2; }
  .sources { grid-template-columns: 1fr; }
}

@media (max-width: 460px) {
  .site-header { min-height: 4rem; }
  .brand { font-size: 0.64rem; letter-spacing: 0.09em; }
  .brand > span { width: 1.1rem; }
  .hero { padding-top: 2rem; gap: 1.1rem; }
  .hero h1 { font-size: clamp(3.25rem, 15.2vw, 4.2rem); }
  .deck { margin-top: 0; font-size: 1.08rem; }
  .hero__number { padding: 0.8rem 0; }
  .hero__number strong { font-size: 5.8rem; }
  .hero__number span { font-size: 1.6rem; }
  .lab__stage { min-height: 42rem; padding-inline: 0.75rem; }
  .slinky { height: 33rem; }
  .readouts strong { font-size: 1.55rem; }
  .lab__controls { padding-inline: 1rem; }
  .story > section { padding-inline: 1rem; }
  .proof__lines p { grid-template-columns: 1fr; gap: 0.45rem; }
  .proof__lines p > :last-child { grid-column: auto; }
  .force-line { gap: 0.45rem; }
  .force-line i { font-size: 2.7rem; }
  footer { display: block; }
  footer a { display: inline-block; margin-top: 0.6rem; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.001ms !important;
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
  }
}