:root {
  color-scheme: light;
  --max: 1280px;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Yu Gothic UI", "Yu Gothic", Meiryo, sans-serif;
  font-synthesis: none;
  text-rendering: optimizeLegibility;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 24px; }
body { margin: 0; background: var(--paper); color: var(--ink); font-size: 17px; line-height: 1.8; overflow-wrap: anywhere; }
img, svg { max-width: 100%; }
a { color: var(--accent-strong); text-underline-offset: .2em; }
a:hover { text-decoration-thickness: 2px; }
:focus-visible { outline: 3px solid var(--focus); outline-offset: 3px; }
h1, h2, h3, p { margin-top: 0; }
h1, h2, h3 { color: var(--accent-strong); line-height: 1.4; letter-spacing: -.025em; }
h1 { font-size: clamp(1.8rem,3vw,2.4rem); }
h2 { font-size: 1.5rem; }
h3 { font-size: 1.25rem; }
p { max-width: 78ch; }
[id] { scroll-margin-top: 24px; }
.site-header { background: var(--paper); border-bottom: 1px solid var(--line); }
.site-header-inner { width: min(var(--max),calc(100% - 64px)); min-height: 68px; margin: auto; display: flex; align-items: center; gap: 24px; }
.brand { flex: none; display: inline-flex; align-items: center; min-height: 44px; color: var(--accent-strong); font-size: 1.12rem; font-weight: 750; letter-spacing: .13em; text-decoration: none; white-space: nowrap; }
.header-nav { display: flex; flex-wrap: wrap; align-items: center; gap: 4px 22px; min-width: 0; margin-left: auto; }
.header-nav a { display: inline-flex; align-items: center; min-height: 44px; color: var(--ink-soft); font-size: .85rem; text-decoration: none; }
.brand-note { color: var(--muted); font-size: .78rem; }
.skip-link { position: absolute; z-index: 10; top: 8px; left: 16px; padding: 10px 16px; min-height: 44px; background: var(--paper); color: var(--ink); border: 2px solid var(--focus); transform: translateY(-160%); }
.skip-link:focus { transform: translateY(0); }
.eyebrow { margin: 0 0 10px; color: var(--accent-strong); font-size: .8rem; letter-spacing: .04em; }
.button { display: inline-flex; align-items: center; justify-content: center; gap: 12px; min-height: 48px; padding: 10px 18px; border: 1px solid var(--accent-strong); font-size: .9rem; line-height: 1.5; text-align: center; text-decoration: none; }
.button:hover { background: var(--tint); }
.site-footer { background: var(--tint); border-top: 1px solid var(--line); }
.site-footer-inner { width: min(var(--max),calc(100% - 64px)); min-height: 82px; margin: auto; display: flex; align-items: center; gap: 20px; }
.site-footer-inner > span { color: var(--ink-soft); font-size: .84rem; }
.site-footer-inner > a:last-child { margin-left: auto; min-height: 44px; display: inline-flex; align-items: center; font-size: .88rem; }
.shell { width: min(1080px,calc(100% - 64px)); margin: auto; padding: 24px 0 80px; }
.breadcrumb, .text-link { display: inline-flex; align-items: center; min-height: 44px; font-size: .85rem; }
.breadcrumb { margin-bottom: 8px; color: var(--ink-soft); }
.notice { padding-block: 45px 80px; }
.responsive-check-main { width: min(1400px,calc(100% - 32px)); margin: auto; padding: 28px 0 60px; }
.viewport-row { margin: 24px 0 35px; }
.viewport-row > h2 { font-size: 1.25rem; }
.viewport-track { display: flex; gap: 18px; overflow-x: auto; padding-bottom: 14px; align-items: flex-start; }
.viewport-column { flex: 0 0 auto; min-width: 0; }
.viewport-label { display: block; width: max-content; margin: 0 0 8px; padding: 3px 9px; background: var(--ink); color: var(--paper); font-size: .8rem; }
.frame-status { margin: 0 0 7px; color: var(--muted); font-size: .76rem; }
.frame-status[data-result="fail"] { font-weight: 750; }
.viewport-frame { display: block; box-sizing: content-box; border: 0; outline: 1px solid var(--line); background: var(--surface); }
@media (max-width: 1100px) { .brand-note { display: none; } }
@media (max-width: 760px) {
  .site-header-inner { width: calc(100% - 36px); min-height: 62px; gap: 14px; flex-wrap: wrap; padding-block: 7px; }
  .brand { font-size: 1.05rem; }
  .header-nav { gap: 4px 14px; }
  .header-nav a { font-size: .8rem; }
  .reader-page .header-nav .desktop-category { display: none; }
  .shell { width: calc(100% - 36px); padding-top: 18px; padding-bottom: 55px; }
  .site-footer-inner { width: calc(100% - 36px); display: grid; grid-template-columns: 1fr; gap: 2px; padding-block: 20px; }
  .site-footer-inner > a:last-child { margin-left: 0; }
}
@media (max-width: 370px) {
  .site-header-inner, .shell, .site-footer-inner { width: calc(100% - 32px); }
  .header-nav { gap: 4px 10px; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}