:root {
  --paper: #faf8f4;
  --surface: #ffffff;
  --ink: #302c29;
  --muted: #6c625c;
  --accent: #a43b2f;
  --accent-dark: #803025;
  --tint: #f0e1d8;
  --line: #d7cdc4;
  --rule: #b9aaa0;
  --focus: #a43b2f;
  --shadow: #302c291a;
  font-family: -apple-system, BlinkMacSystemFont, 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
  color: var(--ink);
  background: var(--paper);
}
* { box-sizing: border-box; }
body { margin: 0; background: var(--paper); }
a { color: inherit; text-underline-offset: .25em; }
button { font: inherit; }
a, button { -webkit-tap-highlight-color: transparent; }
:focus-visible { outline: 3px solid var(--focus); outline-offset: 5px; }
[hidden] { display: none !important; }
.skip-link { position: fixed; top: -100px; left: 20px; padding: 12px 20px; background: var(--surface); z-index: 5; }
.skip-link:focus { top: 12px; }
.wrap { width: min(1160px, calc(100% - 96px)); margin-inline: auto; }
.site-header { border-bottom: 1px solid var(--line); }
.header-inner { display: flex; justify-content: space-between; align-items: center; gap: 24px; min-height: 104px; }
.brand { display: flex; align-items: center; gap: 15px; text-decoration: none; }
.brand img { width: 44px; height: 44px; }
.brand strong { display: block; font-size: 21px; letter-spacing: .12em; }
.brand small { display: block; margin-top: 4px; font-size: 11px; letter-spacing: .025em; color: var(--muted); }
.main-nav { display: flex; align-items: center; gap: 30px; }
.main-nav a { font-size: 14px; text-decoration: none; padding-block: 12px; border-bottom: 2px solid transparent; }
.main-nav a[aria-current] { color: var(--accent); border-color: var(--accent); }
.main-nav a:hover, .text-link:hover { color: var(--accent); }
.main-nav button { border: 1px solid var(--accent); background: var(--surface); color: var(--accent); padding: 9px 14px; cursor: pointer; }
.page-intro { padding: 58px 0 38px; }
.eyebrow { margin: 0 0 20px; font-size: 11px; letter-spacing: .16em; color: var(--accent); line-height: 1.8; }
h1 { margin: 0; font-size: clamp(34px, 4.4vw, 60px); font-weight: 600; line-height: 1.2; letter-spacing: -.045em; }
h1 span { color: var(--accent); }
.intro-line { display: flex; align-items: flex-end; justify-content: space-between; gap: 48px; margin-top: 27px; }
.intro-line p { max-width: 560px; margin: 0; font-size: 15px; line-height: 1.9; color: var(--muted); }
.intro-tag { flex-shrink: 0; font-size: 11px; color: var(--muted); letter-spacing: .14em; }
.collaboration { display: grid; grid-template-columns: 170px minmax(0, 1fr); gap: 32px; padding-bottom: 48px; }
.diagram-heading { padding-top: 24px; border-top: 1px solid var(--rule); }
.diagram-heading h2 { font-size: 19px; font-weight: 500; margin: 0 0 15px; }
.diagram-heading span { display: block; max-width: 120px; font-size: 10px; line-height: 1.8; letter-spacing: .12em; color: var(--muted); }
.flow-board { background: var(--surface); border: 1px solid var(--rule); }
.flow-track { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); }
.flow-stage { position: relative; padding: 32px 24px 30px; min-width: 0; }
.flow-stage + .flow-stage { border-left: 1px solid var(--line); }
.stage-track { display: flex; align-items: center; gap: 12px; color: var(--accent); margin-bottom: 24px; }
.track-dot { width: 11px; height: 11px; border: 2px solid var(--accent); border-radius: 50%; flex-shrink: 0; }
.stage-track::after { content: ''; height: 1px; background: var(--line); flex: 1; }
.stage-name { font-size: 10px; letter-spacing: .13em; }
.flow-stage:not(:last-child)::after { content: '→'; position: absolute; right: -14px; top: 31px; width: 27px; text-align: center; z-index: 1; color: var(--accent); background: var(--surface); font-size: 20px; }
.flow-stage h3 { font-size: 29px; font-weight: 600; letter-spacing: -.03em; margin: 0 0 14px; }
.flow-stage p { font-size: 14px; line-height: 1.9; color: var(--muted); margin: 0; }
.stage-foot { display: block; margin-top: 25px; font-size: 11px; letter-spacing: .035em; color: var(--accent); }
.feedback-line { display: flex; gap: 24px; align-items: center; padding: 16px 32px; border-top: 1px solid var(--line); background: var(--tint); font-size: 12px; }
.feedback-line strong { color: var(--accent); font-weight: 500; white-space: nowrap; }
.feedback-line span { line-height: 1.8; color: var(--muted); }
.practice { display: grid; grid-template-columns: 170px minmax(0, 1fr); gap: 32px; border-top: 1px solid var(--line); padding: 44px 0 52px; }
.practice-heading h2 { font-size: 23px; font-weight: 500; margin: 0; line-height: 1.5; }
.practice-heading p { font-size: 12px; color: var(--muted); margin: 16px 0 0; }
.practice-body { display: grid; grid-template-columns: 1.1fr 1fr; gap: 64px; }
.development-note { border-left: 3px solid var(--accent); padding: 2px 0 2px 24px; }
.practice h3 { margin: 0 0 12px; font-size: 17px; font-weight: 600; }
.practice p { color: var(--muted); font-size: 14px; line-height: 1.95; }
.development-note p { margin: 0 0 17px; }
.format-pair { display: flex; gap: 32px; margin-top: 28px; padding-top: 18px; border-top: 1px solid var(--line); }
.format-pair span { font-size: 12px; color: var(--muted); }
.format-pair b { display: inline-block; margin-right: 8px; font-size: 19px; color: var(--accent); font-weight: 500; }
.publishing-note p { margin: 0; }
.publishing-note h3:nth-of-type(2) { margin-top: 27px; }
.product { display: grid; grid-template-columns: 170px minmax(0, 1fr); gap: 32px; border-top: 1px solid var(--line); padding: 40px 0 44px; }
.product-heading h2 { margin: 0; font-size: 23px; font-weight: 500; line-height: 1.5; }
.product-link { display: grid; grid-template-columns: minmax(0, 1fr) 180px; align-items: center; gap: 44px; border-left: 3px solid var(--accent); padding-left: 24px; text-decoration: none; }
.product-copy h3 { margin: 0 0 14px; font-size: 23px; font-weight: 600; line-height: 1.4; overflow-wrap: anywhere; }
.product-copy p { margin: 0; font-size: 14px; line-height: 1.95; color: var(--muted); }
.product-action { display: inline-block; margin-top: 18px; font-size: 12px; color: var(--accent); }
.product-action span { margin-left: 12px; }
.product-logo { display: block; width: 100%; height: auto; }
.product-link:hover h3, .contact-links a:hover { color: var(--accent); }
.product-link:hover .product-action { text-decoration: underline; }
.company-link { display: flex; justify-content: space-between; align-items: center; gap: 30px; border-top: 1px solid var(--line); padding: 30px 0 36px; }
.company-link p { font-size: 14px; line-height: 1.8; margin: 0; color: var(--muted); }
.company-link strong { display: block; color: var(--ink); margin-bottom: 3px; font-weight: 500; }
.text-link { font-size: 14px; text-decoration: none; white-space: nowrap; border-bottom: 1px solid var(--rule); padding-bottom: 8px; }
.text-link span { margin-left: 20px; color: var(--accent); }
.site-footer { border-top: 1px solid var(--rule); background: var(--surface); }
.footer-inner { display: grid; grid-template-columns: 1fr auto; gap: 12px 32px; padding: 26px 0; }
.footer-inner strong { font-weight: 500; font-size: 13px; }
.footer-company-en { grid-column: 1 / -1; font-size: 12px; color: var(--muted); }
.footer-inner a, .footer-inner small { font-size: 11px; color: var(--muted); line-height: 1.8; }
.footer-inner small { grid-column: 1 / -1; }
.floating-game { position: fixed; right: 24px; bottom: 24px; z-index: 3; max-width: calc(100% - 48px); padding: 14px 20px; border: 0; background: var(--accent); color: var(--surface); cursor: pointer; box-shadow: 0 4px 18px var(--shadow); }
.floating-game:hover { background: var(--accent-dark); }
.about-intro { padding-bottom: 40px; }
.about-intro h1 { font-size: clamp(32px, 4vw, 48px); }
.about-intro .lede { max-width: 720px; margin: 22px 0 0; font-size: 16px; line-height: 1.95; color: var(--muted); }
.company-sheet { display: grid; grid-template-columns: 220px 1fr; gap: 46px; border-top: 1px solid var(--rule); padding: 32px 0 40px; }
.sheet-caption h2 { font-size: 23px; font-weight: 500; margin: 0 0 10px; }
.sheet-caption p { color: var(--muted); font-size: 12px; line-height: 1.8; margin: 0; }
.company-facts { margin: 0; }
.company-facts > div { display: grid; grid-template-columns: 120px 1fr; gap: 16px; padding: 15px 0; border-bottom: 1px solid var(--line); }
.company-facts > div:first-child { padding-top: 0; }
.company-facts dt { font-size: 12px; color: var(--muted); line-height: 1.9; }
.company-facts dd { margin: 0; font-size: 14px; line-height: 1.8; overflow-wrap: anywhere; }
.business-note { display: grid; grid-template-columns: 220px minmax(0, 1fr); gap: 46px; border-top: 1px solid var(--line); padding: 38px 0; }
.business-note h2 { font-size: 25px; font-weight: 500; margin: 0 0 24px; }
.business-copy { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 60px; }
.business-copy h3 { font-size: 17px; margin: 0 0 12px; font-weight: 600; }
.business-copy p { font-size: 14px; color: var(--muted); line-height: 2; margin: 0; }
.contact-strip { margin-bottom: 42px; padding: 24px 28px; background: var(--tint); display: grid; grid-template-columns: minmax(0, 1fr) auto; align-items: center; gap: 24px; }
.contact-strip h2 { font-size: 17px; margin: 0 0 8px; font-weight: 500; }
.contact-strip p { font-size: 13px; margin: 0; line-height: 1.8; color: var(--muted); }
.contact-links { display: flex; flex-direction: column; gap: 10px; min-width: 0; }
.contact-links a { font-size: 22px; white-space: nowrap; color: var(--accent); text-decoration: none; }
.contact-links a + a { font-size: 14px; white-space: normal; overflow-wrap: anywhere; }
@media (max-width: 850px) {
  .product { grid-template-columns: 1fr; gap: 22px; }
  .product-link { gap: 28px; }
  .wrap { width: calc(100% - 48px); }
  .flow-stage { padding: 26px 20px; }
  .flow-stage:not(:last-child)::after { top: 25px; }
  .flow-stage h3 { font-size: 24px; }
  .practice-body { gap: 32px; }
  .company-sheet { grid-template-columns: 160px 1fr; gap: 28px; }
  .business-copy { gap: 32px; }
  .collaboration, .practice { grid-template-columns: 1fr; gap: 22px; }
  .diagram-heading { display: flex; align-items: center; justify-content: space-between; padding-top: 16px; }
  .diagram-heading h2 { margin: 0; font-size: 15px; }
  .diagram-heading span { max-width: none; }
  .practice-heading h2 { font-size: 25px; }
  .business-note { grid-template-columns: 160px minmax(0, 1fr); gap: 28px; }
}
@media (max-width: 600px) {
  .wrap { width: calc(100% - 40px); }
  .header-inner { min-height: 90px; gap: 14px; flex-wrap: wrap; padding-block: 18px; }
  .brand { gap: 10px; }
  .brand img { width: 34px; height: 34px; }
  .brand strong { font-size: 17px; }
  .brand small { font-size: 9px; }
  .product { padding: 30px 0 36px; }
  .product-link { grid-template-columns: minmax(0, 1fr) 96px; gap: 18px; padding-left: 18px; align-items: start; }
  .product-copy h3 { font-size: 20px; }
  .product-copy p, .product-action { grid-column: 1 / -1; }
  .product-copy { display: contents; }
  .product-copy h3 { grid-column: 1; align-self: center; margin: 0; }
  .product-logo { grid-column: 2; grid-row: 1; }
  .product-action { margin-top: 0; }
  .main-nav { gap: 18px; flex-wrap: wrap; }
  .main-nav a { font-size: 12px; padding-block: 9px; }
  .main-nav button { font-size: 12px; }
  .page-intro { padding: 36px 0 29px; }
  h1 { font-size: 36px; }
  .eyebrow { font-size: 10px; margin-bottom: 16px; }
  .intro-line { display: block; margin-top: 19px; }
  .intro-line p { font-size: 14px; }
  .intro-tag { display: block; margin-top: 18px; font-size: 10px; }
  .diagram-heading span { font-size: 8px; }
  .flow-track { grid-template-columns: 1fr; }
  .flow-stage { padding: 24px; }
  .flow-stage + .flow-stage { border-left: 0; border-top: 1px solid var(--line); }
  .flow-stage:not(:last-child)::after { content: '↓'; right: 25px; top: auto; bottom: -14px; }
  .stage-track { margin-bottom: 16px; }
  .flow-stage h3 { font-size: 26px; }
  .stage-foot { margin-top: 18px; }
  .feedback-line { padding: 17px 24px; gap: 6px; flex-direction: column; align-items: flex-start; }
  .collaboration { padding-bottom: 34px; }
  .practice { padding: 30px 0 36px; }
  .practice-heading { display: block; }
  .practice-heading h2 { font-size: 24px; }
  .practice-heading p { margin-top: 10px; }
  .practice-body { grid-template-columns: 1fr; gap: 28px; }
  .development-note { padding-left: 18px; }
  .company-link { align-items: flex-start; flex-direction: column; gap: 20px; }
  .footer-inner { grid-template-columns: 1fr; gap: 8px; padding-bottom: 30px; }
  .about-intro .lede { font-size: 14px; }
  .company-sheet { grid-template-columns: 1fr; gap: 22px; padding: 26px 0 32px; }
  .company-facts > div { grid-template-columns: 75px 1fr; gap: 14px; }
  .company-facts dd { font-size: 13px; }
  .business-note { padding: 29px 0; grid-template-columns: 1fr; gap: 0; }
  .business-copy { grid-template-columns: 1fr; gap: 24px; }
  .contact-strip { grid-template-columns: 1fr; padding: 22px; margin-bottom: 30px; gap: 16px; }
}