:root {
  --ink: #192231;
  --muted: #687386;
  --border: #e5e9ef;
  --blue: #2868f2;
  --blue-soft: #edf3ff;
  --surface: #ffffff;
  --page: #f8fafc;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  color: var(--ink);
  background: var(--page);
  font: 16px/1.65 "DM Sans", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

button, input { font: inherit; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 3;
  display: flex;
  align-items: center;
  gap: 36px;
  min-height: 68px;
  padding: 0 40px;
  border-bottom: 1px solid var(--border);
  background: rgb(255 255 255 / 94%);
  backdrop-filter: blur(12px);
}

.brand { display: inline-flex; align-items: center; gap: 10px; color: var(--ink); text-decoration: none; font-size: 18px; }
.brand strong { font-weight: 600; }
.brand-divider { color: #cbd2dc; }
.brand-mark { display: grid; place-items: center; width: 28px; height: 28px; color: white; background: linear-gradient(135deg, #29b9df, #2563eb 62%, #173a9f); border-radius: 9px 9px 9px 2px; font-weight: 700; }
.top-nav { display: flex; gap: 28px; }
.top-nav a { color: #4d5869; text-decoration: none; font-weight: 500; }
.top-nav a:hover { color: var(--blue); }
.header-actions { display: flex; align-items: center; gap: 10px; margin-left: auto; }
.search { display: flex; align-items: center; gap: 9px; width: min(360px, 27vw); padding: 8px 12px; color: #98a1af; border: 1px solid #d8dee7; border-radius: 999px; background: white; }
.search input { width: 100%; border: 0; outline: 0; color: var(--ink); background: transparent; }
.language-toggle { padding: 7px 11px; color: #435168; border: 1px solid #d8dee7; border-radius: 7px; background: white; cursor: pointer; }

.help-layout { display: grid; grid-template-columns: 285px minmax(0, 780px) 195px; justify-content: center; min-height: calc(100vh - 68px); }
.sidebar { padding: 42px 24px 48px 40px; border-right: 1px solid var(--border); background: #fff; }
.sidebar-heading { margin-bottom: 15px; color: #7a8494; font-size: 12px; font-weight: 700; letter-spacing: .07em; text-transform: uppercase; }
.nav-group { margin: 0 0 20px; }
.nav-group-title { margin: 0 0 7px; color: #4c5768; font-size: 14px; font-weight: 700; }
.nav-link { display: block; margin: 2px 0; padding: 8px 11px; color: #5c6675; border-radius: 7px; text-decoration: none; font-size: 14px; line-height: 1.35; }
.nav-link:hover { color: var(--blue); background: #f5f8ff; }
.nav-link.active { color: var(--blue); background: #eaf0ff; font-weight: 600; }

.article { padding: 47px 52px 72px; background: var(--surface); }
.breadcrumb { margin: 0 0 24px; color: #7b8595; font-size: 14px; }
.breadcrumb span { margin: 0 5px; color: #b0b8c4; }
.article h1 { margin: 0 0 8px; font-size: clamp(31px, 4vw, 42px); line-height: 1.2; letter-spacing: -.035em; }
.article h2 { margin: 42px 0 12px; padding-top: 4px; font-size: 24px; line-height: 1.25; letter-spacing: -.02em; }
.article h3 { margin: 25px 0 6px; font-size: 18px; }
.article p, .article li { color: #465163; }
.article .intro { max-width: 670px; margin: 0 0 18px; color: #5b6778; font-size: 18px; }
.article-meta { display: flex; gap: 14px; align-items: center; color: #7a8494; font-size: 14px; }
.article-meta span:first-child { display: inline-flex; align-items: center; gap: 5px; }
.callout { display: flex; gap: 11px; margin: 28px 0; padding: 17px 19px; border: 1px solid #d8e5ff; border-radius: 8px; background: var(--blue-soft); color: #36527a; }
.callout.warning { border-color: #f3e1ae; background: #fff9e9; color: #715920; }
.article table { width: 100%; margin: 18px 0; border-collapse: collapse; font-size: 14px; }
.article th, .article td { padding: 12px; border: 1px solid var(--border); text-align: left; vertical-align: top; }
.article th { background: #f6f8fb; color: #303a49; font-weight: 700; }
.article ul, .article ol { padding-left: 24px; }
.article li { margin: 8px 0; }
.article code { padding: 2px 5px; border-radius: 4px; background: #f0f3f7; color: #31405a; }
.article pre { overflow-x: auto; padding: 16px; border-radius: 8px; background: #172033; color: #eaf0ff; font: 13px/1.55 ui-monospace, SFMono-Regular, Menlo, monospace; white-space: pre-wrap; }
.article pre code { padding: 0; background: transparent; color: inherit; }
.article-image { margin: 24px 0 6px; }
.article-image img { display: block; width: 100%; border: 1px solid var(--border); border-radius: 8px; box-shadow: 0 12px 28px rgb(32 48 78 / 12%); }
.article-image figcaption { margin-top: 9px; color: var(--muted); font-size: 13px; text-align: center; }
.article-feedback { display: flex; align-items: center; justify-content: space-between; gap: 18px; margin-top: 48px; padding-top: 23px; border-top: 1px solid var(--border); }
.article-feedback p { margin: 0; font-weight: 600; }
.article-feedback button { margin-left: 7px; padding: 6px 16px; color: #516073; border: 1px solid #d8dee7; border-radius: 6px; background: white; cursor: pointer; }

.on-page { padding: 47px 24px; border-left: 1px solid var(--border); background: #fff; }
.on-page > p { margin: 0 0 12px; font-weight: 700; }
.toc-link { display: block; padding: 6px 0 6px 13px; color: #778294; border-left: 2px solid #e5e9ef; text-decoration: none; font-size: 14px; line-height: 1.35; }
.toc-link:hover { color: var(--blue); border-color: var(--blue); }

@media (max-width: 1050px) {
  .help-layout { grid-template-columns: 240px minmax(0, 760px); }
  .on-page { display: none; }
  .sidebar { padding-left: 24px; }
}

@media (max-width: 760px) {
  .site-header { gap: 12px; min-height: auto; padding: 13px 18px; flex-wrap: wrap; }
  .top-nav { display: none; }
  .header-actions { margin-left: auto; }
  .search { width: 180px; }
  .help-layout { display: block; }
  .sidebar { padding: 18px; border-right: 0; border-bottom: 1px solid var(--border); }
  .nav-group { display: inline-block; width: 49%; vertical-align: top; }
  .article { padding: 32px 22px 60px; }
}