:root {
  --bg: #f7f8fb;
  --surface: #ffffff;
  --ink: #18202f;
  --muted: #5c6678;
  --line: #dce2ea;
  --brand: #0d6b78;
  --brand-dark: #084c56;
  --accent: #b84a22;
  --accent-soft: #fff0ea;
  --code: #10212b;
  --focus: #f0b429;
  --shadow: 0 10px 28px rgba(24, 32, 47, .08);
  --radius: 8px;
  --max: 1120px;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: Arial, Helvetica, sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.65;
}
img { max-width: 100%; height: auto; display: block; }
a { color: var(--brand); text-decoration-thickness: .08em; text-underline-offset: .18em; }
a:hover { color: var(--brand-dark); }
a:focus, button:focus, input:focus, textarea:focus, select:focus { outline: 3px solid var(--focus); outline-offset: 3px; }
.skip-link { position: absolute; left: -999px; top: 1rem; background: var(--ink); color: white; padding: .7rem 1rem; z-index: 10; }
.skip-link:focus { left: 1rem; }
.site-header { background: var(--surface); border-bottom: 1px solid var(--line); position: sticky; top: 0; z-index: 5; }
.header-inner { max-width: var(--max); margin: 0 auto; padding: 1rem; display: flex; align-items: center; justify-content: space-between; gap: 1rem; }
.logo { display: inline-flex; align-items: center; gap: .55rem; color: var(--ink); font-weight: 800; text-decoration: none; }
.logo-mark { width: 2rem; height: 2rem; border-radius: 7px; background: var(--brand); color: #fff; display: grid; place-items: center; font-size: .9rem; }
.nav-list { list-style: none; display: flex; flex-wrap: wrap; gap: .8rem 1rem; padding: 0; margin: 0; }
.nav-list a { color: var(--ink); font-weight: 700; text-decoration: none; font-size: .95rem; }
.nav-list a:hover { color: var(--brand); }
.hero { background: #eef8f7; border-bottom: 1px solid var(--line); }
.hero-inner { max-width: var(--max); margin: 0 auto; padding: 4rem 1rem; display: grid; grid-template-columns: 1.08fr .92fr; gap: 2rem; align-items: center; }
.hero h1 { font-size: clamp(2.1rem, 5vw, 4.4rem); line-height: 1.05; margin: 0 0 1rem; letter-spacing: 0; }
.hero p { font-size: 1.12rem; color: var(--muted); max-width: 62ch; margin: 0 0 1.4rem; }
.hero-actions { display: flex; flex-wrap: wrap; gap: .75rem; }
.button { display: inline-flex; align-items: center; justify-content: center; min-height: 44px; padding: .72rem 1rem; border-radius: 7px; border: 1px solid var(--brand); background: var(--brand); color: #fff; font-weight: 800; text-decoration: none; }
.button.secondary { background: #fff; color: var(--brand); }
.hero-visual { min-height: 280px; border-radius: var(--radius); overflow: hidden; box-shadow: var(--shadow); background: #fff; }
.section { max-width: var(--max); margin: 0 auto; padding: 3rem 1rem; }
.section.tight { padding-top: 2rem; }
.section-head { display: flex; align-items: end; justify-content: space-between; gap: 1rem; margin-bottom: 1.25rem; }
.section-head h2, .page-title h1 { margin: 0; line-height: 1.15; }
.section-head p, .page-title p { color: var(--muted); margin: .4rem 0 0; }
.grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 1rem; }
.grid.two { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.card { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 1.1rem; box-shadow: var(--shadow); }
.card h2, .card h3 { margin-top: 0; line-height: 1.25; }
.card p { color: var(--muted); }
.meta { color: var(--muted); font-size: .92rem; }
.badge { display: inline-block; border: 1px solid var(--line); background: var(--accent-soft); color: #763015; padding: .2rem .55rem; border-radius: 999px; font-size: .82rem; font-weight: 800; }
.breadcrumb { max-width: var(--max); margin: 0 auto; padding: 1rem 1rem 0; color: var(--muted); font-size: .92rem; }
.breadcrumb ol { list-style: none; padding: 0; margin: 0; display: flex; flex-wrap: wrap; gap: .35rem; }
.breadcrumb li:not(:last-child)::after { content: '/'; margin-left: .35rem; color: #8a94a5; }
.page-title { max-width: var(--max); margin: 0 auto; padding: 2rem 1rem 1rem; }
.article-layout { max-width: var(--max); margin: 0 auto; padding: 1rem 1rem 3rem; display: grid; grid-template-columns: minmax(0, 740px) 1fr; gap: 2rem; align-items: start; }
.article-body { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 1.4rem; box-shadow: var(--shadow); }
.article-body h1 { font-size: clamp(2rem, 4vw, 3.2rem); line-height: 1.1; margin-top: 0; }
.article-body h2 { margin-top: 2rem; line-height: 1.2; }
.article-body h3 { margin-top: 1.4rem; }
.article-body pre { background: var(--code); color: #e8f4f8; padding: 1rem; overflow-x: auto; border-radius: 7px; line-height: 1.5; }
.article-body code { font-family: Consolas, Monaco, monospace; font-size: .95em; }
.article-body :not(pre) > code { background: #eef3f6; color: #12242e; padding: .1rem .28rem; border-radius: 4px; }
.aside-box { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 1rem; position: sticky; top: 5.5rem; }
.aside-box h2 { font-size: 1.1rem; margin-top: 0; }
.aside-box ul { padding-left: 1.15rem; }
.info-band { background: #fff; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.form-grid { display: grid; gap: 1rem; }
label { display: block; font-weight: 800; margin-bottom: .35rem; }
input, textarea, select { width: 100%; min-height: 44px; border: 1px solid #b9c3d0; border-radius: 7px; padding: .75rem; font: inherit; background: #fff; }
textarea { min-height: 150px; resize: vertical; }
.site-footer { background: #101823; color: #dce5ee; margin-top: 2rem; }
.footer-inner { max-width: var(--max); margin: 0 auto; padding: 2.5rem 1rem; display: grid; grid-template-columns: 1.2fr repeat(3, 1fr); gap: 1.25rem; }
.site-footer a { color: #e9f7f8; }
.site-footer h2, .site-footer h3 { color: #fff; margin-top: 0; }
.footer-links { list-style: none; padding: 0; margin: 0; display: grid; gap: .45rem; }
.footer-bottom { border-top: 1px solid rgba(255,255,255,.16); max-width: var(--max); margin: 0 auto; padding: 1rem; color: #b8c3cf; }
@media (max-width: 860px) {
  .header-inner { align-items: flex-start; flex-direction: column; }
  .hero-inner, .article-layout { grid-template-columns: 1fr; }
  .grid, .grid.two, .footer-inner { grid-template-columns: 1fr; }
  .section-head { align-items: flex-start; flex-direction: column; }
  .aside-box { position: static; }
}
@media (max-width: 520px) {
  .hero-inner { padding: 2.6rem 1rem; }
  .article-body { padding: 1rem; }
  .nav-list { gap: .55rem .75rem; }
}