.app-header { position: fixed; z-index: 40; inset: 0 0 auto; display: grid; grid-template-columns: var(--sidebar-width) minmax(18rem, 42rem) auto; gap: 1.25rem; align-items: center; height: var(--header-height); padding: 0 1.25rem; background: rgb(255 255 255 / 94%); border-bottom: 1px solid var(--color-neutral-200); backdrop-filter: blur(12px); }
.menu-button { display: none; }
.brand { display: flex; gap: .7rem; align-items: center; color: var(--color-neutral-900); text-decoration: none; }
.brand-mark { display: grid; place-items: center; width: 2.1rem; height: 2.1rem; color: white; background: var(--color-primary-600); border-radius: .6rem; font-size: .68rem; font-weight: 800; letter-spacing: .04em; }
.brand-copy { display: grid; line-height: 1.1; }
.brand-copy strong { font-size: .92rem; }
.brand-copy small { margin-top: .25rem; color: var(--color-neutral-500); font-size: .68rem; }
.search-shell { position: relative; display: grid; grid-template-columns: auto 1fr auto; gap: .55rem; align-items: center; padding: .48rem .7rem; background: var(--color-neutral-50); border: 1px solid var(--color-neutral-200); border-radius: var(--radius-md); }
.search-shell:focus-within { border-color: var(--color-primary-500); box-shadow: 0 0 0 3px rgb(116 66 189 / 12%); }
.search-shell input { min-width: 0; padding: 0; background: transparent; border: 0; outline: 0; }
.search-shell kbd { padding: .13rem .35rem; color: var(--color-neutral-500); background: white; border: 1px solid var(--color-neutral-200); border-radius: .3rem; font-family: var(--font-sans); font-size: .65rem; box-shadow: 0 1px 0 var(--color-neutral-200); }
.search-results { position: absolute; z-index: 60; top: calc(100% + .55rem); right: 0; left: 0; max-height: min(70vh, 34rem); overflow-y: auto; padding: .4rem; background: white; border: 1px solid var(--color-neutral-200); border-radius: var(--radius-md); box-shadow: var(--shadow-lg); }
.search-result { display: grid; gap: .15rem; padding: .7rem; color: inherit; border-radius: var(--radius-sm); text-decoration: none; }
.search-result:hover, .search-result[aria-selected="true"] { background: var(--color-primary-50); }
.search-result strong { font-size: .85rem; }
.search-result span { color: var(--color-neutral-500); font-size: .72rem; }
.search-empty { padding: 1rem; color: var(--color-neutral-500); text-align: center; font-size: .82rem; }
.app-layout { display: grid; grid-template-columns: var(--sidebar-width) minmax(0, 1fr) var(--toc-width); min-height: 100vh; padding-top: var(--header-height); }
.sidebar { position: fixed; z-index: 30; top: var(--header-height); bottom: 0; left: 0; display: flex; flex-direction: column; width: var(--sidebar-width); background: white; border-right: 1px solid var(--color-neutral-200); }
.sidebar nav { flex: 1; overflow-y: auto; padding: 1rem .75rem; }
.nav-group { margin-bottom: .3rem; }
.nav-group summary { display: flex; gap: .55rem; align-items: center; padding: .55rem .6rem; border-radius: var(--radius-sm); cursor: pointer; list-style: none; font-size: .78rem; font-weight: 700; }
.nav-group summary::-webkit-details-marker { display: none; }
.nav-group summary::before { content: "›"; color: var(--color-neutral-500); transition: transform .15s; }
.nav-group[open] summary::before { transform: rotate(90deg); }
.nav-group summary:hover { background: var(--color-neutral-50); }
.nav-list { display: grid; gap: .12rem; margin: .2rem 0 .6rem; padding: 0; list-style: none; }
.nav-link { display: grid; grid-template-columns: 2.65rem 1fr; gap: .35rem; padding: .42rem .55rem; color: var(--color-neutral-700); border-radius: var(--radius-sm); text-decoration: none; font-size: .75rem; }
.nav-link:hover { color: var(--color-neutral-900); background: var(--color-neutral-50); }
.nav-link.active { color: var(--color-primary-700); background: var(--color-primary-50); font-weight: 650; }
.nav-id { color: var(--color-neutral-500); font-variant-numeric: tabular-nums; }
.sidebar-footer { display: grid; gap: .15rem; padding: .9rem 1rem; color: var(--color-neutral-500); background: var(--color-neutral-25); border-top: 1px solid var(--color-neutral-200); font-size: .68rem; }
.sidebar-footer strong { color: var(--color-neutral-700); }
.drawer-backdrop { display: none; }
.main-content { grid-column: 2; min-width: 0; padding: 2.2rem clamp(1.25rem, 4vw, 4rem) 5rem; }
.content-container { width: min(100%, var(--content-width)); margin: 0 auto; }
.article-toc { position: fixed; top: var(--header-height); right: 0; bottom: 0; width: var(--toc-width); overflow-y: auto; padding: 2rem 1.2rem; color: var(--color-neutral-500); border-left: 1px solid var(--color-neutral-200); font-size: .72rem; }
.article-toc strong { display: block; margin-bottom: .65rem; color: var(--color-neutral-700); font-size: .72rem; }
.article-toc a { display: block; margin-bottom: .45rem; color: inherit; text-decoration: none; }
.article-toc a.level-3 { padding-left: .7rem; }
.article-toc a:hover { color: var(--color-primary-600); }
.hero { padding: 2rem; background: linear-gradient(135deg, var(--color-primary-50), white 65%); border: 1px solid var(--color-primary-100); border-radius: var(--radius-lg); }
.eyebrow { margin: 0 0 .5rem; color: var(--color-primary-600); font-size: .72rem; font-weight: 800; letter-spacing: .08em; text-transform: uppercase; }
.hero h1 { max-width: 38rem; margin: 0; font-size: clamp(1.8rem, 4vw, 2.7rem); line-height: 1.08; letter-spacing: -.035em; }
.hero p { max-width: 38rem; margin: .9rem 0 0; color: var(--color-neutral-700); }
.stats { display: grid; grid-template-columns: repeat(3, 1fr); gap: .8rem; margin: 1.2rem 0 2rem; }
.stat { padding: 1rem; background: white; border: 1px solid var(--color-neutral-200); border-radius: var(--radius-md); }
.stat strong { display: block; font-size: 1.25rem; }
.stat span { color: var(--color-neutral-500); font-size: .75rem; }
.section-heading { margin: 2rem 0 .9rem; font-size: 1.15rem; }
.card-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: .8rem; }
.article-header { padding-bottom: 1.4rem; border-bottom: 1px solid var(--color-neutral-200); }
.article-header h1 { margin: .5rem 0 .65rem; font-size: clamp(1.75rem, 4vw, 2.45rem); line-height: 1.12; letter-spacing: -.035em; }
.article-header p { margin: 0; color: var(--color-neutral-500); }
.article-meta { display: flex; flex-wrap: wrap; gap: .5rem; align-items: center; }
.article-body { padding-top: 1.5rem; font-size: .94rem; }
.article-body h1 { display: none; }
.article-body h2 { margin: 2.2rem 0 .8rem; padding-top: .4rem; font-size: 1.35rem; line-height: 1.25; }
.article-body h3 { margin: 1.6rem 0 .6rem; font-size: 1.05rem; }
.article-body img { max-width: 100%; height: auto; }
.article-body li + li { margin-top: .28rem; }

@media (max-width: 1120px) {
  .app-layout { grid-template-columns: var(--sidebar-width) minmax(0, 1fr); }
  .article-toc { display: none; }
}
@media (max-width: 800px) {
  .app-header { grid-template-columns: auto 1fr auto; gap: .7rem; padding: 0 .8rem; }
  .menu-button { display: grid; }
  .brand-copy { display: none; }
  .search-shell kbd { display: none; }
  .app-layout { display: block; }
  .sidebar { top: 0; z-index: 55; width: min(88vw, 20rem); padding-top: var(--header-height); transform: translateX(-105%); transition: transform .2s ease; box-shadow: var(--shadow-lg); }
  body.drawer-open { overflow: hidden; }
  body.drawer-open .sidebar { transform: translateX(0); }
  .drawer-backdrop { position: fixed; z-index: 50; inset: 0; display: block; background: rgb(20 20 28 / 42%); border: 0; }
  .main-content { padding: 1.4rem 1rem 4rem; }
  .card-grid { grid-template-columns: 1fr; }
  .hero { padding: 1.4rem; }
}
@media (max-width: 480px) {
  .app-header { grid-template-columns: auto 1fr; }
  .brand { display: none; }
  .version-badge { display: none; }
  .stats { grid-template-columns: 1fr; gap: .55rem; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; transition-duration: .01ms !important; }
}