:root {
  color-scheme: light;
  --paper: #fff; --ink: #20252a; --muted: #505b65; --rule: #ccd2d7; --accent: #215d8c;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans JP", "Hiragino Kaku Gothic ProN", "Yu Gothic UI", "Meiryo UI", Meiryo, sans-serif;
  font-size: 18px; color: var(--ink); background: var(--paper); font-synthesis: none;
}
* { box-sizing: border-box; }
body { margin: 0; line-height: 1.8; }
a { color: inherit; text-underline-offset: 4px; }
a:hover { color: var(--accent); }
button, input { font: inherit; }
button, .button { min-height: 48px; }
button { cursor: pointer; }
button:disabled { cursor: wait; opacity: .65; }
:focus-visible { outline: 3px solid #b54730; outline-offset: 4px; }
[hidden] { display: none !important; }
img { display: block; max-width: 100%; height: auto; }
.wrap { width: min(1120px, calc(100% - 64px)); margin-inline: auto; }
.skip-link { position: absolute; top: -100px; left: 16px; z-index: 20; padding: 10px 16px; background: white; }
.skip-link:focus { top: 12px; }
.site-header { display: flex; justify-content: space-between; align-items: center; min-height: 86px; gap: 24px; border-bottom: 2px solid var(--ink); }
.brand { text-decoration: none; display: flex; flex-wrap: wrap; align-items: baseline; gap: 6px 18px; }
.brand strong { font-family: Arial, sans-serif; font-size: 24px; }
.brand span { font-size: 16px; }
.site-nav { display: flex; gap: 24px; font-size: 16px; }
.site-nav a { display: inline-flex; align-items: center; min-height: 48px; }
.eyebrow, .number, .meta { font-size: 15px; }
.eyebrow { color: var(--accent); font-weight: 700; margin: 0 0 12px; }
.home-intro { padding: 42px 0 36px; }
h1, h2, h3 { line-height: 1.5; overflow-wrap: anywhere; }
.home-intro h1 { font-size: clamp(30px, 3.6vw, 44px); margin: 0 0 18px; }
.lede { max-width: 850px; margin: 0; }
.intro-note { font-size: 16px; color: var(--muted); margin: 16px 0 0; }
.section-heading { border-bottom: 2px solid var(--ink); padding-bottom: 16px; }
.section-heading h2 { margin: 0; font-size: 24px; }
.experiment-list { margin: 0; padding: 0; list-style: none; }
.experiment-row { display: grid; grid-template-columns: 36px minmax(0, 1fr) 170px 90px; gap: 20px; align-items: center; padding: 28px 0; border-bottom: 1px solid var(--rule); }
.experiment-row .number { align-self: start; padding-top: 8px; color: var(--muted); font-weight: 700; }
.experiment-row h3 { font-size: 26px; margin: 0 0 10px; }
.experiment-row h3 a { text-decoration: none; }
.experiment-row h3 a:hover { text-decoration: underline; }
.experiment-row .description { font-size: 17px; margin: 0; }
.experiment-row .meta { display: block; color: var(--muted); margin-top: 12px; }
.experiment-row .art { width: 170px; }
.row-arrow { display: flex; align-items: center; justify-content: center; min-height: 48px; padding: 8px 12px; font-size: 18px; font-weight: 700; color: var(--accent); border: 1px solid currentColor; text-decoration: none; white-space: nowrap; }
.row-arrow:hover { background: #edf5fb; }
.home-about { max-width: 850px; margin: 48px 0; }
.home-about h2 { font-size: 26px; margin: 0 0 20px; }
.home-about p { margin: 0 0 16px; }
.breadcrumbs { display: flex; flex-wrap: wrap; list-style: none; gap: 6px 12px; padding: 0; margin: 22px 0 0; font-size: 14px; color: var(--muted); }
.breadcrumbs li + li::before { content: "/"; margin-right: 12px; }
.page-intro { padding: 30px 0; }
.page-intro h1 { font-size: clamp(30px, 3.6vw, 42px); margin: 0 0 16px; }
.experience-layout, .article-layout { display: grid; grid-template-columns: minmax(0, 780px) minmax(210px, 1fr); gap: 32px; align-items: start; }
.experience-stage { min-width: 0; }
.stage-label { display: flex; flex-wrap: wrap; align-items: baseline; justify-content: space-between; gap: 8px 16px; margin-bottom: 12px; }
.stage-label h2 { font-size: 22px; margin: 0; }
.stage-label span { font-size: 15px; color: var(--muted); }
.stage-surface { position: relative; background: #f0f4f6; border: 1px solid var(--rule); }
.poster { width: 100%; aspect-ratio: 16 / 9; object-fit: cover; object-position: center 32%; }
.start-panel { position: relative; display: flex; flex-direction: column; align-items: center; padding: 22px 16px; background: white; border-top: 1px solid var(--rule); }
.start-panel .button { background: var(--accent); color: #fff; border: 2px solid var(--accent); padding: 12px 24px; font-size: 20px; font-weight: 700; line-height: 1.6; text-align: center; }
.start-panel .button:hover { background: #17466c; }
.start-panel p { color: var(--muted); font-size: 15px; margin: 12px 0 0; text-align: center; }
.stage-surface iframe { position: absolute; inset: 0; width: 100%; height: 100%; border: 0; display: block; background: #111; visibility: hidden; }
.stage-surface.is-running iframe { position: relative; height: var(--runner-height, 580px); visibility: visible; }
.stage-surface.is-loading .poster { opacity: .25; }
.stage-status { margin: 0; padding: 14px 0; font-size: 15px; color: var(--muted); }
.stage-actions { display: flex; flex-wrap: wrap; justify-content: space-between; align-items: center; gap: 0 20px; border-bottom: 1px solid var(--rule); }
.stop-button { background: white; border: 1px solid #92402a; padding: 8px 14px; margin-bottom: 12px; color: #92402a; font-size: 16px; }
.brief { border-top: 2px solid var(--ink); padding-top: 16px; margin-top: 45px; }
.brief h2 { font-size: 20px; margin: 0 0 16px; }
.brief dl { margin: 0; font-size: 17px; }
.brief dt { color: var(--muted); font-size: 15px; margin: 16px 0 4px; }
.brief dd { margin: 0; font-weight: 700; }
.brief p { font-size: 15px; margin: 20px 0 10px; }
.brief a { font-size: 15px; }
.article-layout { margin-top: 44px; }
.content-section { margin-bottom: 44px; }
.content-section h2 { font-size: 26px; margin: 0 0 22px; border-top: 2px solid var(--ink); padding-top: 20px; }
.content-section p { margin: 0 0 16px; }
.steps { list-style: none; padding: 0; margin: 0; counter-reset: step; }
.steps li { position: relative; counter-increment: step; padding: 0 0 26px 40px; }
.steps li::before { content: counter(step) "."; position: absolute; left: 0; top: 0; font-size: 22px; font-weight: 700; color: var(--accent); }
.steps h3 { font-size: 21px; margin: 0 0 8px; }
.steps p { margin: 0; }
.callout { border-left: 4px solid var(--accent); padding: 14px 18px; margin: 24px 0; background: #f1f5f8; }
.callout p:last-child { margin-bottom: 0; }
.warning { border-left-color: #ae4326; background: #fff3e9; color: #602613; font-size: 16px; }
.faq { border-bottom: 1px solid var(--rule); }
.faq summary { font-size: 18px; font-weight: 700; cursor: pointer; padding: 18px 0; }
.faq p { padding-bottom: 14px; }
.related { border-top: 1px solid var(--rule); padding-top: 18px; }
.related h2 { font-size: 19px; margin: 0 0 12px; }
.related ul { list-style: none; padding: 0; margin: 0; }
.related a { display: block; font-size: 16px; padding: 16px 0; border-bottom: 1px solid var(--rule); }
.site-footer { margin-top: 24px; border-top: 2px solid var(--ink); padding: 24px 0 32px; display: flex; flex-wrap: wrap; gap: 18px; align-items: center; justify-content: space-between; }
.site-footer p { margin: 0; font-size: 14px; }
.footer-links { display: flex; flex-wrap: wrap; gap: 12px 22px; font-size: 15px; }
.footer-links a { display: inline-flex; align-items: center; min-height: 44px; }
.policy { max-width: 820px; margin: 0 0 60px; }
.policy h2 { font-size: 25px; margin: 32px 0 14px; }
.policy li { margin-bottom: 12px; }
.noscript { padding: 20px; border: 1px solid #ac4c30; background: #fff8ee; }
.magic-page { --accent: #a3321b; }
.magic-page h1, .magic-row h3 { color: #852813; }
.magic-page h1 span { display: inline-block; }
.magic-note { padding: 12px 16px; border-left: 4px solid #b2431f; background: #fff3dd; max-width: 850px; font-weight: 700; margin: 20px 0 0; }
.magic-page .start-panel { background: #fff8ee; }
.magic-page .start-panel .button:hover { background: #7d2514; }
.magic-row .row-arrow { color: #a3321b; }
.magic-row .row-arrow:hover { background: #fff3dd; }
@media (max-width: 900px) {
  .wrap { width: calc(100% - 40px); }
  .experiment-row { grid-template-columns: 32px minmax(0, 1fr) 120px 90px; gap: 16px; }
  .experiment-row .art { width: 120px; }
  .experience-layout, .article-layout { grid-template-columns: minmax(0, 1fr); gap: 28px; }
  .brief { margin-top: 0; }
  .brief dl { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 12px 20px; }
  .brief dt { margin-top: 0; }
  .related { margin-bottom: 24px; }
}
@media (max-width: 600px) {
  :root { font-size: 17px; }
  .wrap { width: calc(100% - 32px); }
  .site-header { min-height: 80px; gap: 12px; }
  .brand { display: block; }
  .brand strong { font-size: 21px; }
  .brand span { display: block; font-size: 14px; }
  .site-nav { font-size: 15px; }
  .site-nav .root-link { display: none; }
  .home-intro { padding: 30px 0; }
  .home-intro h1, .page-intro h1 { font-size: 30px; }
  .home-intro .lede br { display: none; }
  .intro-note { font-size: 15px; }
  .section-heading h2 { font-size: 21px; }
  .experiment-row { grid-template-columns: 28px minmax(0, 1fr); gap: 12px; padding: 24px 0; }
  .experiment-row h3 { font-size: 24px; }
  .experiment-row .art { display: none; }
  .experiment-row .row-arrow { grid-column: 2; justify-self: start; min-width: 120px; }
  .experiment-row .meta { font-size: 14px; }
  .home-about { margin: 36px 0; }
  .home-about h2 { font-size: 24px; }
  .page-intro { padding: 26px 0; }
  .start-panel { padding: 18px 12px; }
  .start-panel .button { width: 100%; padding: 12px 10px; font-size: 18px; }
  .start-panel p { font-size: 14px; }
  .brief dl { grid-template-columns: 1fr; gap: 14px; }
  .brief dl > div { display: grid; grid-template-columns: 72px minmax(0, 1fr); gap: 10px; }
  .brief dt { margin: 0; }
  .content-section h2 { font-size: 24px; }
  .steps li { padding-left: 32px; }
  .steps h3 { font-size: 20px; }
  .callout { padding: 12px 14px; }
  .magic-note { font-size: 16px; }
}
@media (prefers-reduced-motion: reduce) { *, *::before, *::after { scroll-behavior: auto !important; } }