/* Layout: one long page laid out along a 14 m piste. A red line on the left fills as you scroll (0 m at the top, 14 m at the sign-up); each section sits at its own metre mark. Dark on purpose: it is the app's own look (black, white, piste red). */
  :root {
    color-scheme: dark;
    --ink: #070606;
    --panel: #0d0b0b;
    --line: #2e2a2a;
    --text: #f3f1ef;
    --mute: #948e8e;
    --dim: #3a3536;
    --red: #ff1f2e;
    --red-deep: #a80f1b;
    --good: #2fd06b;
    --warn: #f2b632;
    --poor: #ff4b55;
    --display: "Barlow Condensed", "Arial Narrow", Impact, sans-serif;
    --body: "IBM Plex Sans", "Segoe UI", system-ui, sans-serif;
    --data: "IBM Plex Mono", Consolas, monospace;
    --p: 0;
  }
  * { box-sizing: border-box; }
  html { scroll-behavior: smooth; }
  body { background: var(--ink); color: var(--text); font: 17px/1.6 var(--body); margin: 0; overflow-x: clip; }
  a { color: inherit; }
  :focus-visible { outline: 2px solid var(--red); outline-offset: 3px; }
  .wrap { max-width: 1120px; margin: 0 auto; padding-inline: clamp(16px, 4vw, 40px); }
  section { padding-block: clamp(56px, 9vw, 112px); border-top: 1px solid var(--line); }
  h1, h2, h3 { font-family: var(--display); font-weight: 700; text-transform: uppercase; letter-spacing: .03em; margin: 0; text-wrap: balance; line-height: .95; }
  h2 { font-size: clamp(40px, 6vw, 72px); }
  h3 { font-size: 30px; letter-spacing: .05em; }
  p { margin: 0; }
  .lede { font-size: clamp(18px, 2vw, 21px); color: var(--mute); max-width: 56ch; }
  .eyebrow { font: 500 13px/1 var(--data); letter-spacing: .16em; text-transform: uppercase; color: var(--red); display: block; margin-bottom: 18px; }
  .eyebrow span { color: var(--mute); }
  .mono { font-family: var(--data); font-variant-numeric: tabular-nums; }
  .example { font: 500 12px/1 var(--data); letter-spacing: .12em; text-transform: uppercase; color: var(--mute); border: 1px solid var(--line); padding: 6px 9px; display: inline-block; }
  .btn { font: 700 22px/1 var(--display); letter-spacing: .08em; text-transform: uppercase; padding: 15px 26px 12px; border: 1px solid var(--mute); color: var(--text); background: transparent; cursor: pointer; text-decoration: none; display: inline-block; }
  .btn:hover { border-color: var(--text); }
  .btn.go { background: var(--red); border-color: var(--red); color: #fff; }
  .btn.go:hover { background: #ff3a47; }
  .btn.q { border-color: var(--line); color: var(--mute); }
  .btn:disabled { opacity: .45; cursor: not-allowed; }

  /* top bar */
  header.nav { position: sticky; top: env(safe-area-inset-top, 0px); z-index: 20; background: rgba(7,6,6,.86); backdrop-filter: blur(8px); border-bottom: 1px solid var(--line); }
  .nav .wrap { display: flex; align-items: center; gap: 28px; height: 60px; }
  .brand { font: 700 26px/1 var(--display); letter-spacing: .2em; text-decoration: none; }
  .brand i { font-style: normal; color: var(--red); }
  .nav nav { display: flex; gap: 26px; margin-left: auto; align-items: center; }
  .nav nav a { font: 500 13px/1 var(--data); letter-spacing: .14em; text-transform: uppercase; color: var(--mute); text-decoration: none; }
  .nav nav a:hover { color: var(--text); }
  .nav .btn { padding: 11px 16px 9px; font-size: 18px; }
  @media (max-width: 760px) { .nav nav a:not(.btn) { display: none; } }

  /* the piste rail */
  .rail { position: fixed; left: 26px; top: 110px; bottom: 60px; width: 60px; z-index: 5; display: none; pointer-events: none; }
  .rail .track { position: absolute; left: 0; top: 0; bottom: 0; width: 2px; background: var(--dim); }
  .rail .fill { position: absolute; left: 0; top: 0; width: 2px; height: calc(var(--p) * 100%); background: var(--red); }
  .rail .fill::after { content: ""; position: absolute; left: -4px; bottom: -5px; width: 10px; height: 10px; border-radius: 50%; background: var(--red); }
  .rail .tick { position: absolute; left: 0; display: flex; align-items: center; gap: 8px; font: 500 10px/1 var(--data); letter-spacing: .1em; color: var(--mute); transform: translateY(-50%); }
  .rail .tick::before { content: ""; width: 10px; height: 1px; background: var(--mute); }
  .rail .now { position: absolute; left: 0; top: -30px; font: 500 12px/1 var(--data); letter-spacing: .1em; color: var(--text); }
  @media (min-width: 1320px) { .rail { display: block; } }

  /* hero */
  .hero { border-top: 0; padding-top: clamp(36px, 6vw, 72px); overflow: hidden; }
  .hero .grid { display: grid; grid-template-columns: 1.1fr .9fr; gap: clamp(20px, 4vw, 56px); align-items: center; }
  .hero h1 { font-size: clamp(50px, 7.6vw, 108px); line-height: .88; margin-bottom: 26px; }
  .lede-small { margin-top: 14px; font: 500 13px/1.5 var(--data); letter-spacing: .12em; text-transform: uppercase; color: var(--mute); }
  .hero h1 em { font-style: normal; color: var(--red); }
  .hero .actions { display: flex; gap: 14px; flex-wrap: wrap; margin-top: 32px; }
  .hero .art { position: relative; aspect-ratio: 1.45; }
  .hero .art img { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: contain; mix-blend-mode: lighten; transform: scale(1.22); }
  .status { margin-top: 26px; font: 500 13px/1.4 var(--data); letter-spacing: .12em; text-transform: uppercase; color: var(--mute); display: flex; gap: 10px; align-items: center; }
  .status::before { content: ""; width: 9px; height: 9px; border-radius: 50%; background: var(--warn); flex: none; }
  @media (max-width: 860px) { .hero .grid { grid-template-columns: 1fr; } .hero .art { order: -1; max-height: 300px; } }

  /* speed strip under the hero */
  .strip { margin-top: clamp(28px, 5vw, 56px); border: 1px solid var(--line); background: var(--panel); }
  .strip .top { display: flex; align-items: center; gap: 16px; padding: 14px 18px; border-bottom: 1px solid var(--line); flex-wrap: wrap; }
  .strip .top .grow { flex: 1; }
  .strip .top button.btn { padding: 9px 14px 7px; font-size: 17px; }
  .chartbox { position: relative; height: clamp(200px, 30vw, 320px); }
  svg.chart { display: block; width: 100%; height: 100%; }
  svg.chart text { font-family: var(--data); fill: var(--mute); }
  svg.chart .val { fill: var(--text); }
  .trace { fill: none; stroke-linecap: round; stroke-linejoin: round; }
  .trace.draw { stroke-dasharray: 1; stroke-dashoffset: 1; animation: drawline 1.6s cubic-bezier(.3,.6,.2,1) forwards; }
  .trace.draw.hip { animation-delay: .12s; }
  .fade { opacity: 0; animation: fadein .5s ease 1.4s forwards; }
  @keyframes drawline { to { stroke-dashoffset: 0; } }
  @keyframes fadein { to { opacity: 1; } }
  @media (prefers-reduced-motion: reduce) { .trace.draw { animation: none; stroke-dashoffset: 0; } .fade { animation: none; opacity: 1; } html { scroll-behavior: auto; } }

  /* interactive graphics: a hint with a pulsing dot, and a pointer cursor */
  .hint { font: 500 13px/1.2 var(--data); letter-spacing: .1em; text-transform: uppercase; color: var(--text); display: flex; align-items: center; gap: 10px; min-height: 18px; }
  .pulse { width: 9px; height: 9px; border-radius: 50%; background: var(--red); display: inline-block; flex: none; animation: pulse 1.7s ease-in-out infinite; }
  @keyframes pulse { 0%, 100% { box-shadow: 0 0 0 0 rgba(255,31,46,.65); } 50% { box-shadow: 0 0 0 8px rgba(255,31,46,0); } }
  @media (prefers-reduced-motion: reduce) { .pulse { animation: none; } }
  .live { cursor: ew-resize; touch-action: pan-y; -webkit-user-select: none; user-select: none; }
  .strip:hover, .demo:hover, .progress .chartwrap:hover { border-color: var(--mute); }

  /* what it measures */
  .cells { display: grid; grid-template-columns: repeat(4, 1fr); margin-top: 44px; border-top: 1px solid var(--line); }
  .cell { padding: 26px 24px 8px 0; border-right: 1px solid var(--line); padding-left: 24px; }
  .cell:first-child { padding-left: 0; }
  .cell:last-child { border-right: 0; }
  .cell .label { font: 500 13px/1 var(--data); letter-spacing: .16em; text-transform: uppercase; color: var(--mute); }
  .cell .num { font: 700 clamp(64px, 8vw, 104px)/.85 var(--display); margin-top: 16px; font-variant-numeric: tabular-nums; }
  .cell .num small { font: 500 15px/1 var(--data); color: var(--mute); margin-left: 8px; letter-spacing: .06em; }
  .cell p { color: var(--mute); font-size: 16px; margin-top: 16px; max-width: 30ch; }
  @media (max-width: 900px) { .cells { grid-template-columns: 1fr 1fr; } .cell:nth-child(2) { border-right: 0; } .cell:nth-child(3) { padding-left: 0; } .cell { padding-bottom: 24px; border-bottom: 1px solid var(--line); } }
  @media (max-width: 480px) { .cells { grid-template-columns: 1fr; } .cell { border-right: 0; padding-left: 0; } }
  .how-measured { margin-top: 36px; max-width: 70ch; color: var(--mute); border-left: 3px solid var(--red); padding-left: 18px; }

  /* replay demo */
  .demo { display: grid; grid-template-columns: 1fr 1fr; margin-top: 44px; border: 1px solid var(--line); background: var(--panel); }
  .demo .pic { position: relative; border-right: 1px solid var(--line); min-height: 320px; }
  .demo .pic svg { position: absolute; inset: 0; width: 100%; height: 100%; }
  .demo .pic .cap, .panel .cap { position: absolute; left: 16px; top: 14px; font: 500 12px/1 var(--data); letter-spacing: .14em; text-transform: uppercase; color: var(--mute); z-index: 2; }
  .demo .side { display: flex; flex-direction: column; min-height: 0; }
  .demo .side .chartbox { flex: 1; min-height: 200px; }
  .demo .now { padding: 14px 18px; font: 500 14px/1.4 var(--data); letter-spacing: .08em; text-transform: uppercase; border-bottom: 1px solid var(--line); display: flex; gap: 22px; flex-wrap: wrap; }
  .demo .now b { font-weight: 500; color: var(--text); }
  .controls { grid-column: 1 / 3; display: flex; gap: 12px; align-items: center; padding: 14px 18px; border-top: 1px solid var(--line); flex-wrap: wrap; }
  .controls .btn { padding: 11px 16px 9px; font-size: 19px; }
  .controls input[type=range] { flex: 1; min-width: 160px; accent-color: var(--red); height: 32px; }
  .controls .frame { font: 500 13px/1 var(--data); letter-spacing: .1em; color: var(--mute); min-width: 128px; text-align: right; }
  @media (max-width: 820px) { .demo { grid-template-columns: 1fr; } .demo .pic { border-right: 0; border-bottom: 1px solid var(--line); min-height: 260px; } .controls { grid-column: 1; } }

  /* progress */
  .progress { display: grid; grid-template-columns: .8fr 1.2fr; gap: clamp(24px, 5vw, 64px); align-items: center; }
  .progress .big { font: 700 clamp(100px, 16vw, 210px)/.8 var(--display); color: var(--red); letter-spacing: 0; }
  .progress .big small { display: block; font: 500 14px/1.4 var(--data); letter-spacing: .12em; text-transform: uppercase; color: var(--mute); margin-top: 20px; }
  .progress .chartwrap { border: 1px solid var(--line); background: var(--panel); }
  .progress .chartbox { height: clamp(240px, 32vw, 360px); }
  .legend { display: flex; gap: 22px; flex-wrap: wrap; padding: 14px 18px; border-bottom: 1px solid var(--line); font: 500 12px/1 var(--data); letter-spacing: .1em; text-transform: uppercase; color: var(--mute); align-items: center; }
  .legend span { display: flex; align-items: center; gap: 8px; }
  .legend i { width: 24px; height: 3px; background: var(--red); display: block; }
  .legend i.hip { background: var(--text); }
  .legend i.ring { width: 11px; height: 11px; border: 2px solid var(--mute); border-radius: 50%; background: none; }
  @media (max-width: 860px) { .progress { grid-template-columns: 1fr; } }

  /* coaching */
  .coach { display: grid; grid-template-columns: 1fr 1fr; margin-top: 44px; border: 1px solid var(--line); background: var(--panel); }
  .panel { position: relative; min-height: 340px; }
  .panel + .panel { border-left: 1px solid var(--line); }
  .panel svg { position: absolute; inset: 0; width: 100%; height: 100%; }
  .panel .note { position: absolute; z-index: 2; font: 500 12px/1.2 var(--data); letter-spacing: .1em; text-transform: uppercase; color: var(--poor); left: 50%; top: 45%; }
  .scorebar { grid-column: 1 / 3; border-top: 1px solid var(--line); padding: 22px 24px; display: grid; grid-template-columns: auto 1fr; gap: 12px 40px; align-items: center; }
  .score { font: 700 clamp(64px, 8vw, 96px)/.85 var(--display); color: var(--warn); }
  .score small { font: 500 13px/1 var(--data); letter-spacing: .14em; color: var(--mute); display: block; margin-bottom: 8px; text-transform: uppercase; }
  .checks { display: grid; grid-template-columns: 1fr 1fr; gap: 14px 32px; }
  .check .row { display: flex; justify-content: space-between; font: 700 22px/1 var(--display); letter-spacing: .05em; text-transform: uppercase; }
  .check .bar { height: 5px; background: var(--dim); margin-top: 8px; position: relative; }
  .check .bar i { position: absolute; inset: 0 auto 0 0; display: block; }
  .check .bar::after { content: ""; position: absolute; left: 85%; top: -4px; bottom: -4px; width: 2px; background: var(--mute); }
  .check.good { color: var(--good); } .check.good i { background: var(--good); }
  .check.warn { color: var(--warn); } .check.warn i { background: var(--warn); }
  .check.poor { color: var(--poor); } .check.poor i { background: var(--poor); }
  @media (max-width: 820px) { .coach { grid-template-columns: 1fr; } .panel + .panel { border-left: 0; border-top: 1px solid var(--line); } .scorebar { grid-column: 1; grid-template-columns: 1fr; } .checks { grid-template-columns: 1fr; } }

  /* what is in the app */
  .parts { display: grid; grid-template-columns: repeat(4, 1fr); margin-top: 44px; border-top: 1px solid var(--line); }
  .part { padding: 26px 24px 26px 0; }
  .part + .part { padding-left: 24px; border-left: 1px solid var(--line); }
  .part h3 { font-size: 34px; margin-bottom: 12px; color: var(--red); }
  .part p { color: var(--mute); font-size: 16px; }
  .setup-note { margin-top: 12px; max-width: 70ch; color: var(--mute); border-left: 3px solid var(--red); padding-left: 18px; }
  .setup-note b { color: var(--text); font-weight: 500; }
  .about-ai { margin-top: 56px; max-width: 70ch; border-top: 1px solid var(--line); padding-top: 36px; }
  .about-ai h3 { color: var(--red); margin-bottom: 14px; }
  .about-ai p { color: var(--mute); }
  .facts { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 36px; }
  .facts span { font: 500 13px/1 var(--data); letter-spacing: .1em; text-transform: uppercase; border: 1px solid var(--line); padding: 10px 14px; color: var(--mute); }
  @media (max-width: 900px) { .parts { grid-template-columns: 1fr 1fr; } .part:nth-child(3) { padding-left: 0; border-left: 0; } .part:nth-child(n+3) { border-top: 1px solid var(--line); } }
  @media (max-width: 520px) { .parts { grid-template-columns: 1fr; } .part + .part { padding-left: 0; border-left: 0; border-top: 1px solid var(--line); } }

  /* who it is for */
  .two { display: grid; grid-template-columns: 1fr 1fr; gap: clamp(24px, 5vw, 72px); margin-top: 44px; }
  .two h3 { margin-bottom: 18px; color: var(--red); }
  .two ul { list-style: none; padding: 0; margin: 0; display: grid; gap: 14px; }
  .two li { padding-left: 22px; position: relative; color: var(--mute); }
  .two li::before { content: ""; position: absolute; left: 0; top: .7em; width: 10px; height: 2px; background: var(--red); }
  .two li b { color: var(--text); font-weight: 500; }
  @media (max-width: 760px) { .two { grid-template-columns: 1fr; } }

  /* waitlist */
  .signup { display: grid; grid-template-columns: 1fr 1fr; gap: clamp(28px, 6vw, 88px); align-items: start; }
  form { display: grid; gap: 18px; }
  label { display: grid; gap: 8px; font: 500 12px/1 var(--data); letter-spacing: .14em; text-transform: uppercase; color: var(--mute); }
  input[type=text], input[type=email], select, textarea { font: 500 20px/1.3 var(--body); background: var(--panel); color: var(--text); border: 1px solid var(--line); padding: 14px 16px; width: 100%; border-radius: 0; }
  textarea { min-height: 96px; resize: vertical; }
  input:focus, select:focus, textarea:focus { outline: 0; border-color: var(--red); box-shadow: inset 0 -3px 0 var(--red); }
  select { appearance: none; background-image: linear-gradient(45deg, transparent 50%, var(--mute) 50%), linear-gradient(135deg, var(--mute) 50%, transparent 50%); background-position: calc(100% - 22px) 55%, calc(100% - 16px) 55%; background-size: 6px 6px; background-repeat: no-repeat; }
  .msg { font: 500 14px/1.5 var(--data); letter-spacing: .04em; min-height: 22px; }
  .msg.ok { color: var(--good); } .msg.err { color: var(--warn); }
  .thanks { border: 1px solid var(--good); padding: 30px; }
  .thanks h3 { color: var(--good); margin-bottom: 10px; }
  @media (max-width: 860px) { .signup { grid-template-columns: 1fr; } }

  footer { border-top: 1px solid var(--line); padding-block: 40px; color: var(--mute); }
  footer a.mail { color: var(--text); text-transform: none; letter-spacing: .06em; text-decoration: none; border-bottom: 1px solid var(--red); padding-bottom: 2px; }
  footer .wrap { display: flex; gap: 20px; flex-wrap: wrap; align-items: center; justify-content: space-between; font: 500 13px/1.5 var(--data); letter-spacing: .1em; text-transform: uppercase; }