/* Physics Quest website
   Layout idea: a lab notebook on graph paper. Measurements sit in mono, one live trajectory in the hero.
   No web fonts, cookies or analytics: everything is served from this folder. */
:root {
  --paper: #f6f8fc;
  --grid: rgba(47, 102, 214, 0.07);
  --ink: #1d2140;
  --muted: #5a6080;
  --line: #d8dfee;
  --card: #ffffff;
  --accent: #f2611d;
  --accent-ink: #ffffff;
  --display: ui-rounded, "SF Pro Rounded", "Arial Rounded MT Bold", "Nunito", system-ui, sans-serif;
  --body: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --mono: ui-monospace, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;
  --radius: 14px;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --paper: #0e1830;
    --grid: rgba(140, 178, 255, 0.08);
    --ink: #e9eeff;
    --muted: #a3afcf;
    --line: #253559;
    --card: #14213d;
    --accent: #ff8247;
    --accent-ink: #1a0f08;
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --paper: #0e1830;
  --grid: rgba(140, 178, 255, 0.08);
  --ink: #e9eeff;
  --muted: #a3afcf;
  --line: #253559;
  --card: #14213d;
  --accent: #ff8247;
  --accent-ink: #1a0f08;
  color-scheme: dark;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background-color: var(--paper);
  background-image:
    linear-gradient(var(--grid) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid) 1px, transparent 1px);
  background-size: 24px 24px;
  color: var(--ink);
  font: 17px/1.6 var(--body);
}
img { max-width: 100%; display: block; }
a { color: var(--accent); text-underline-offset: 3px; }
a:focus-visible, button:focus-visible { outline: 3px solid var(--accent); outline-offset: 3px; border-radius: 6px; }
h1, h2, h3 { font-family: var(--display); line-height: 1.12; text-wrap: balance; margin: 0; }
h1 { font-size: clamp(2.6rem, 6vw, 4.4rem); font-weight: 800; letter-spacing: -0.02em; }
h2 { font-size: clamp(1.7rem, 3.4vw, 2.4rem); font-weight: 800; letter-spacing: -0.01em; }
h3 { font-size: 1.2rem; font-weight: 800; }
p { margin: 0; }
.mono { font-family: var(--mono); font-size: 0.82rem; letter-spacing: 0.01em; }
.muted { color: var(--muted); }

.wrap { width: min(1120px, 100% - 32px); margin-inline: auto; }

/* Header */
.site-header { border-bottom: 1px solid var(--line); background: color-mix(in srgb, var(--paper) 88%, transparent); backdrop-filter: blur(6px); position: sticky; top: 0; z-index: 10; }
.site-header .wrap { display: flex; align-items: center; justify-content: space-between; gap: 16px; padding-block: 12px; flex-wrap: wrap; }
.brand { display: flex; align-items: center; gap: 10px; color: var(--ink); text-decoration: none; font-family: var(--display); font-weight: 800; font-size: 1.15rem; }
.brand img { width: 36px; height: 36px; border-radius: 9px; }
.site-nav { display: flex; gap: 18px; flex-wrap: wrap; }
.site-nav a { color: var(--muted); text-decoration: none; font-weight: 600; font-size: 0.95rem; }
.site-nav a:hover, .site-nav a[aria-current="page"] { color: var(--ink); }

/* Hero */
.hero { padding-block: 56px 40px; display: grid; grid-template-columns: 1.05fr 1fr; gap: 40px; align-items: center; }
.hero .lede { font-size: 1.2rem; color: var(--muted); max-width: 34ch; margin-top: 18px; }
.eyebrow { display: inline-block; font-family: var(--mono); font-size: 0.8rem; color: var(--accent); border: 1px solid currentColor; border-radius: 999px; padding: 3px 10px; margin-bottom: 18px; }
.cta-row { display: flex; gap: 14px; flex-wrap: wrap; align-items: center; margin-top: 28px; }
.store-pill { display: inline-flex; align-items: center; gap: 10px; background: var(--ink); color: var(--paper); border-radius: 12px; padding: 11px 18px; font-weight: 700; }
.store-pill small { display: block; font-weight: 500; opacity: 0.75; font-size: 0.72rem; }
.trust { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 22px; padding: 0; list-style: none; }
.trust li { font-family: var(--mono); font-size: 0.78rem; border: 1px dashed var(--line); background: var(--card); border-radius: 8px; padding: 4px 9px; }

.figure { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 14px; box-shadow: 0 18px 40px -28px rgba(20, 30, 70, 0.45); }
.figure canvas { width: 100%; aspect-ratio: 16 / 10; display: block; border-radius: 8px; }
.figure figcaption { display: flex; justify-content: space-between; gap: 12px; flex-wrap: wrap; margin-top: 10px; color: var(--muted); }

/* Sections */
section { padding-block: 56px; }
.section-head { display: grid; gap: 10px; max-width: 62ch; margin-bottom: 28px; }

.screens { display: grid; grid-template-columns: 1.2fr 1fr; gap: 18px; align-items: start; }
.screens .stack { display: grid; gap: 18px; }
.shot { background: #11131f; border-radius: 22px; padding: 10px; }
.shot img { border-radius: 14px; width: 100%; }
.shot-caption { margin-top: 8px; color: var(--muted); }

.stats { display: grid; grid-template-columns: repeat(5, 1fr); border: 1px solid var(--line); border-radius: var(--radius); background: var(--card); }
.stats div { padding: 18px 16px; border-right: 1px solid var(--line); }
.stats div:last-child { border-right: 0; }
.stats b { display: block; font-family: var(--display); font-size: 2.1rem; font-variant-numeric: tabular-nums; line-height: 1; }
.stats span { color: var(--muted); font-size: 0.92rem; }

.labs { display: grid; grid-template-columns: repeat(4, 1fr); gap: 14px; }
.lab { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 16px 16px 14px; display: grid; gap: 8px; align-content: start; border-top: 6px solid var(--lab); }
.lab .num { font-family: var(--mono); font-size: 0.75rem; color: var(--muted); }
.lab .concept { font-weight: 700; color: var(--lab); filter: saturate(1.1); font-size: 0.92rem; }
.lab p { font-size: 0.95rem; }
.lab .law { font-family: var(--mono); font-size: 0.78rem; background: color-mix(in srgb, var(--lab) 12%, transparent); border-radius: 6px; padding: 4px 8px; justify-self: start; }

.two-col { display: grid; grid-template-columns: 1fr 1fr; gap: 28px; }
.panel { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 22px; }
.checks { list-style: none; padding: 0; margin: 14px 0 0; display: grid; gap: 10px; }
.checks li { padding-left: 28px; position: relative; }
.checks li::before { content: ""; position: absolute; left: 4px; top: 0.55em; width: 12px; height: 7px; border-left: 2.5px solid var(--accent); border-bottom: 2.5px solid var(--accent); transform: rotate(-45deg); }

.faq { display: grid; gap: 10px; }
.faq details { background: var(--card); border: 1px solid var(--line); border-radius: 12px; padding: 14px 18px; }
.faq summary { cursor: pointer; font-weight: 700; }
.faq details p { margin-top: 8px; color: var(--muted); }

.site-footer { border-top: 1px solid var(--line); padding-block: 28px; color: var(--muted); font-size: 0.92rem; }
.site-footer .wrap { display: flex; flex-wrap: wrap; gap: 12px 24px; justify-content: space-between; }
.site-footer nav { display: flex; gap: 18px; flex-wrap: wrap; }

/* Privacy policy */
.policy { display: grid; grid-template-columns: 240px 1fr; gap: 40px; padding-block: 48px 64px; }
.policy aside { position: sticky; top: 84px; align-self: start; }
.policy aside ol { list-style: none; padding: 0; margin: 12px 0 0; display: grid; gap: 6px; font-size: 0.93rem; }
.policy aside a { color: var(--muted); text-decoration: none; }
.policy aside a:hover { color: var(--ink); }
.policy article { max-width: 68ch; }
.policy article h2 { font-size: 1.5rem; margin: 40px 0 10px; scroll-margin-top: 84px; }
.policy article p, .policy article ul { margin: 0 0 12px; }
.policy article ul { padding-left: 1.2em; }
.summary { background: var(--card); border: 1px solid var(--line); border-left: 6px solid var(--accent); border-radius: var(--radius); padding: 18px 20px; margin-top: 24px; }
.summary h2 { margin-top: 0 !important; font-size: 1.2rem !important; }
.ledger { width: 100%; border-collapse: collapse; margin: 6px 0 14px; font-size: 0.95rem; }
.ledger th, .ledger td { text-align: left; border-bottom: 1px solid var(--line); padding: 8px 10px 8px 0; vertical-align: top; }
.ledger th { font-family: var(--mono); font-size: 0.78rem; font-weight: 600; color: var(--muted); }

@media (max-width: 900px) {
  .hero, .two-col, .screens { grid-template-columns: 1fr; }
  .labs { grid-template-columns: repeat(2, 1fr); }
  .stats { grid-template-columns: repeat(2, 1fr); }
  .stats div { border-right: 0; border-bottom: 1px solid var(--line); }
  .policy { grid-template-columns: 1fr; }
  .policy aside { position: static; }
}
@media (max-width: 480px) {
  .labs { grid-template-columns: 1fr; }
  body { font-size: 16px; }
}
@media (prefers-reduced-motion: reduce) {
  * { scroll-behavior: auto !important; }
}