/* Bing History — static site styles */
:root {
  --bg: #f5f7fb;
  --surface: #ffffff;
  --surface-2: #eef2f9;
  --ink: #0f172a;
  --ink-2: #26304a;
  --muted: #566078;
  --line: #e2e8f3;
  --accent: #1d4ed8;
  --accent-hover: #1a43b8;
  --accent-2: #0891b2;
  --accent-soft: #e8efff;
  --on-accent: #ffffff;
  --ok: #059669;
  --shadow-sm: 0 1px 2px rgba(15, 23, 42, .06);
  --shadow: 0 10px 30px -12px rgba(15, 23, 42, .18);
  --radius: 16px;
  --radius-sm: 10px;
  --font: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif;
  --mono: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0a0f1f;
    --surface: #121a30;
    --surface-2: #182244;
    --ink: #eaeefb;
    --ink-2: #ccd4ea;
    --muted: #9aa6c3;
    --line: #232f52;
    --accent: #7ba2ff;
    --accent-hover: #9bb9ff;
    --accent-2: #38bdf8;
    --accent-soft: #1a2750;
    --on-accent: #0a0f1f;
    --ok: #34d399;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, .4);
    --shadow: 0 14px 34px -14px rgba(0, 0, 0, .7);
  }
}

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font);
  font-size: 17px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; height: auto; display: block; }
a { color: var(--accent); text-decoration-thickness: 1px; text-underline-offset: 3px; }
a:hover { color: var(--accent-hover); }
:focus-visible { outline: 3px solid var(--accent); outline-offset: 2px; border-radius: 6px; }
h1, h2, h3, h4 { line-height: 1.2; letter-spacing: -.02em; margin: 0; color: var(--ink); }

.container { width: 100%; max-width: 1160px; margin: 0 auto; padding: 0 20px; }
.skip-link {
  position: absolute; left: -999px; top: 8px; background: var(--accent); color: var(--on-accent);
  padding: 8px 14px; border-radius: 8px; z-index: 100;
}
.skip-link:focus { left: 12px; }

/* ---------- Header ---------- */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: color-mix(in srgb, var(--bg) 86%, transparent);
  backdrop-filter: saturate(160%) blur(14px);
  -webkit-backdrop-filter: saturate(160%) blur(14px);
  border-bottom: 1px solid var(--line);
}
.header-inner { display: flex; align-items: center; gap: 18px; height: 66px; }
.brand { display: inline-flex; align-items: center; gap: 10px; text-decoration: none; color: var(--ink); font-weight: 800; font-size: 19px; letter-spacing: -.02em; }
.brand:hover { color: var(--ink); }
.brand svg { flex: none; }
.brand b { color: var(--accent); font-weight: 800; }
.nav { display: flex; align-items: center; gap: 2px; margin-left: auto; }
.nav a {
  color: var(--ink-2); text-decoration: none; font-weight: 600; font-size: 15px;
  padding: 8px 12px; border-radius: 10px; white-space: nowrap;
}
.nav a:hover, .nav a[aria-current="page"] { background: var(--accent-soft); color: var(--accent); }
.icon-btn {
  display: inline-grid; place-items: center; width: 40px; height: 40px; border-radius: 10px;
  border: 1px solid var(--line); background: var(--surface); color: var(--ink-2); cursor: pointer;
}
.icon-btn:hover { border-color: var(--accent); color: var(--accent); }
.nav-toggle { display: none; }
.header-actions { display: flex; gap: 8px; }

@media (max-width: 980px) {
  .nav-toggle { display: inline-grid; }
  .header-inner { gap: 10px; }
  .header-actions { margin-left: auto; }
  .nav {
    display: none; position: absolute; left: 0; right: 0; top: 66px; margin: 0;
    flex-direction: column; align-items: stretch; padding: 12px 20px 18px;
    background: var(--surface); border-bottom: 1px solid var(--line); box-shadow: var(--shadow);
  }
  .nav.open { display: flex; }
  .nav a { padding: 12px 10px; font-size: 16px; }
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 13px 22px; border-radius: 12px; font-weight: 700; font-size: 16px;
  text-decoration: none; border: 1px solid transparent; cursor: pointer; font-family: inherit;
  transition: transform .15s ease, box-shadow .15s ease, background .15s ease;
}
.btn-primary { background: var(--accent); color: var(--on-accent); box-shadow: 0 8px 20px -8px var(--accent); }
.btn-primary:hover { background: var(--accent-hover); color: var(--on-accent); transform: translateY(-1px); }
.btn-ghost { background: var(--surface); color: var(--ink); border-color: var(--line); }
.btn-ghost:hover { border-color: var(--accent); color: var(--accent); }

/* ---------- Hero ---------- */
.hero {
  position: relative; overflow: hidden; padding: 64px 0 56px;
  background:
    radial-gradient(900px 400px at 85% -10%, color-mix(in srgb, var(--accent) 16%, transparent), transparent 70%),
    radial-gradient(700px 360px at -5% 10%, color-mix(in srgb, var(--accent-2) 14%, transparent), transparent 70%);
  border-bottom: 1px solid var(--line);
}
.hero-grid { display: grid; grid-template-columns: 1.15fr .85fr; gap: 48px; align-items: center; }
.eyebrow {
  display: inline-flex; align-items: center; gap: 8px; padding: 6px 12px; border-radius: 999px;
  background: var(--accent-soft); color: var(--accent); font-weight: 700; font-size: 13px; letter-spacing: .02em;
}
.eyebrow i { width: 7px; height: 7px; border-radius: 50%; background: var(--ok); display: inline-block; }
.hero h1 { font-size: clamp(32px, 5.2vw, 54px); font-weight: 850; margin: 18px 0 16px; }
.hero h1 em { font-style: normal; color: var(--accent); }
.hero p.lead { font-size: 19px; color: var(--muted); max-width: 58ch; margin: 0 0 26px; }
.hero-cta { display: flex; flex-wrap: wrap; gap: 12px; }
.chips { display: flex; flex-wrap: wrap; gap: 10px; margin: 28px 0 0; padding: 0; list-style: none; }
.chips li {
  display: inline-flex; align-items: center; gap: 8px; padding: 8px 14px; border-radius: 999px;
  background: var(--surface); border: 1px solid var(--line); font-size: 14px; font-weight: 600; color: var(--ink-2);
}
.chips svg { color: var(--ok); flex: none; }

.mock {
  background: var(--surface); border: 1px solid var(--line); border-radius: 18px; box-shadow: var(--shadow);
  overflow: hidden;
}
.mock-bar { display: flex; align-items: center; gap: 7px; padding: 12px 14px; background: var(--surface-2); border-bottom: 1px solid var(--line); }
.mock-bar i { width: 10px; height: 10px; border-radius: 50%; background: var(--line); display: inline-block; }
.mock-url {
  margin-left: 10px; flex: 1; background: var(--surface); border: 1px solid var(--line); border-radius: 8px;
  font-size: 13px; padding: 4px 10px; color: var(--muted); font-family: var(--mono); white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}
.mock-body { padding: 22px 22px 24px; }
.mock-body h2 { font-size: 18px; margin-bottom: 14px; }
.steps { list-style: none; margin: 0; padding: 0; display: grid; gap: 12px; counter-reset: s; }
.steps li { display: flex; gap: 12px; align-items: flex-start; font-size: 15.5px; color: var(--ink-2); counter-increment: s; }
.steps li::before {
  content: counter(s); flex: none; width: 28px; height: 28px; border-radius: 50%;
  display: grid; place-items: center; background: var(--accent); color: var(--on-accent); font-weight: 800; font-size: 14px;
}
.mock-done {
  margin-top: 18px; padding: 12px 14px; border-radius: 12px; background: color-mix(in srgb, var(--ok) 12%, var(--surface));
  color: var(--ink-2); font-size: 14.5px; display: flex; gap: 10px; align-items: center;
}
.mock-done svg { color: var(--ok); flex: none; }

@media (max-width: 900px) {
  .hero { padding: 40px 0 40px; }
  .hero-grid { grid-template-columns: 1fr; gap: 32px; }
}

/* ---------- Sections ---------- */
.section { padding: 64px 0; }
.section.alt { background: var(--surface); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.section-head { max-width: 62ch; margin-bottom: 30px; }
.section-head h2 { font-size: clamp(26px, 3.6vw, 36px); font-weight: 800; }
.section-head p { color: var(--muted); margin: 10px 0 0; font-size: 18px; }
.kicker { display: block; color: var(--accent); font-weight: 800; font-size: 13px; letter-spacing: .08em; text-transform: uppercase; margin-bottom: 8px; }

.cat { margin-top: 42px; scroll-margin-top: 84px; }
.cat:first-of-type { margin-top: 0; }
.cat-head { display: flex; align-items: center; gap: 12px; margin-bottom: 16px; }
.cat-icon { width: 40px; height: 40px; border-radius: 12px; display: grid; place-items: center; background: var(--accent-soft); color: var(--accent); flex: none; }
.cat-head h3 { font-size: 21px; font-weight: 800; }
.cat-head p { margin: 0; color: var(--muted); font-size: 15px; }

.card-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 16px; }
.card {
  display: flex; flex-direction: column; gap: 8px; padding: 20px; background: var(--surface);
  border: 1px solid var(--line); border-radius: var(--radius); text-decoration: none; color: var(--ink);
  box-shadow: var(--shadow-sm); transition: transform .15s ease, box-shadow .15s ease, border-color .15s ease;
}
.card:hover { transform: translateY(-3px); box-shadow: var(--shadow); border-color: color-mix(in srgb, var(--accent) 45%, var(--line)); color: var(--ink); }
.card h3, .card h2 { font-size: 18px; font-weight: 750; letter-spacing: -.01em; }
.card p { margin: 0; color: var(--muted); font-size: 15px; line-height: 1.55; flex: 1; }
.card .more { color: var(--accent); font-weight: 700; font-size: 14px; display: inline-flex; gap: 6px; align-items: center; margin-top: 4px; }
.card time { font-size: 13px; color: var(--muted); }
.section.alt .card { background: var(--bg); }

.principles { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.principle { padding: 26px; background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); }
.principle .cat-icon { margin-bottom: 14px; }
.principle h3 { font-size: 19px; margin-bottom: 8px; }
.principle p { margin: 0; color: var(--muted); font-size: 16px; }
@media (max-width: 860px) { .principles { grid-template-columns: 1fr; } }

.cta {
  margin: 0 auto; padding: 44px 32px; text-align: center; border-radius: 24px; color: #fff;
  background: linear-gradient(135deg, #1e3a8a, #1d4ed8 55%, #0891b2);
  box-shadow: var(--shadow);
}
.cta h2 { color: #fff; font-size: clamp(24px, 3.4vw, 34px); margin-bottom: 10px; }
.cta p { margin: 0 auto 22px; max-width: 52ch; color: #dbe6ff; }
.cta .btn { background: #fff; color: #1e3a8a; box-shadow: none; }
.cta .btn:hover { background: #eef3ff; color: #1e3a8a; }

/* ---------- Article ---------- */
.page-top { padding: 34px 0 10px; }
.breadcrumb { font-size: 14px; color: var(--muted); display: flex; flex-wrap: wrap; gap: 8px; align-items: center; margin-bottom: 14px; }
.breadcrumb a { color: var(--muted); text-decoration: none; }
.breadcrumb a:hover { color: var(--accent); }
.breadcrumb span[aria-hidden] { opacity: .5; }
.page-top h1 { font-size: clamp(30px, 4.6vw, 46px); font-weight: 850; max-width: 24ch; }
.page-top.wide h1 { max-width: none; }
.meta { display: flex; flex-wrap: wrap; gap: 10px 16px; align-items: center; margin-top: 16px; color: var(--muted); font-size: 14.5px; }
.pill { display: inline-block; padding: 4px 11px; border-radius: 999px; background: var(--accent-soft); color: var(--accent); font-weight: 700; font-size: 13px; text-decoration: none; }
a.pill:hover { background: var(--accent); color: var(--on-accent); }

.article-wrap { display: grid; grid-template-columns: minmax(0, 1fr) 270px; gap: 48px; align-items: start; padding: 26px 0 64px; }
.article-wrap.no-toc { grid-template-columns: minmax(0, 1fr); max-width: 800px; margin-left: auto; margin-right: auto; }
.article {
  background: var(--surface); border: 1px solid var(--line); border-radius: 20px; padding: 40px 44px;
  box-shadow: var(--shadow-sm); min-width: 0;
}
@media (max-width: 1080px) {
  .article-wrap { grid-template-columns: minmax(0, 1fr); }
  .toc-box { display: none; }
}
@media (max-width: 640px) {
  .article { padding: 24px 18px; border-radius: 16px; }
  body { font-size: 16.5px; }
}

.toc-box { position: sticky; top: 88px; }
.toc { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 18px 18px 14px; }
.toc h2 { font-size: 13px; letter-spacing: .08em; text-transform: uppercase; color: var(--muted); margin-bottom: 10px; }
.toc ol { list-style: none; margin: 0; padding: 0; max-height: 60vh; overflow: auto; }
.toc li a {
  display: block; padding: 6px 10px; margin-left: -10px; border-left: 2px solid transparent;
  color: var(--ink-2); font-size: 14.5px; line-height: 1.4; text-decoration: none; border-radius: 0 8px 8px 0;
}
.toc li a:hover { color: var(--accent); background: var(--accent-soft); }
.toc li a.active { color: var(--accent); border-left-color: var(--accent); font-weight: 700; }

.prose { font-size: 17.5px; color: var(--ink-2); }
.prose > :first-child { margin-top: 0; }
.prose h2 { font-size: 28px; font-weight: 800; margin: 2.1em 0 .6em; padding-top: .2em; scroll-margin-top: 86px; color: var(--ink); }
.prose h3 { font-size: 21px; font-weight: 750; margin: 1.8em 0 .5em; scroll-margin-top: 86px; color: var(--ink); }
.prose h4 { font-size: 18px; font-weight: 750; margin: 1.5em 0 .4em; color: var(--ink); }
.prose p { margin: 0 0 1.05em; }
.prose ul, .prose ol { margin: 0 0 1.2em; padding-left: 1.4em; }
.prose li { margin: .35em 0; padding-left: .2em; }
.prose li > ul, .prose li > ol { margin: .4em 0 .5em; }
.prose li::marker { color: var(--accent); font-weight: 700; }
.prose strong { color: var(--ink); }
.prose code { font-family: var(--mono); font-size: .88em; background: var(--surface-2); border: 1px solid var(--line); padding: .12em .4em; border-radius: 6px; word-break: break-word; }
.prose img { border: 1px solid var(--line); border-radius: 12px; margin: 1.3em auto; box-shadow: var(--shadow-sm); }
.prose hr { border: 0; border-top: 1px solid var(--line); margin: 2em 0; }
.table-wrap { overflow-x: auto; margin: 1.4em 0; border: 1px solid var(--line); border-radius: 12px; -webkit-overflow-scrolling: touch; }
.prose table { border-collapse: collapse; width: 100%; font-size: 15.5px; min-width: 520px; }
.prose th { text-align: left; background: var(--surface-2); color: var(--ink); font-weight: 750; }
.prose th, .prose td { padding: 11px 14px; border-bottom: 1px solid var(--line); vertical-align: top; }
.prose tr:last-child td { border-bottom: 0; }
.prose tbody tr:nth-child(even) td { background: color-mix(in srgb, var(--surface-2) 45%, transparent); }

.quicknav { background: var(--accent-soft); border: 1px solid color-mix(in srgb, var(--accent) 22%, var(--line)); border-radius: 14px; padding: 16px 20px 6px; margin: 1.4em 0; }
.quicknav p { margin: 0 0 6px; }
.quicknav ul { list-style: none; padding: 0; margin: 0 0 10px; display: flex; flex-wrap: wrap; gap: 8px; }
.quicknav li { margin: 0; padding: 0; }
.quicknav a { display: inline-block; padding: 6px 13px; border-radius: 999px; background: var(--surface); border: 1px solid var(--line); text-decoration: none; font-weight: 650; font-size: 15px; }
.quicknav a:hover { border-color: var(--accent); }

.related { padding: 0 0 64px; }
.related h2 { font-size: 24px; margin-bottom: 18px; }

/* ---------- Footer ---------- */
.site-footer { background: var(--surface); border-top: 1px solid var(--line); padding: 52px 0 26px; font-size: 15px; }
.footer-grid { display: grid; grid-template-columns: 1.5fr 1fr 1fr 1fr; gap: 32px; }
.footer-grid h2 { font-size: 13px; letter-spacing: .08em; text-transform: uppercase; color: var(--muted); margin-bottom: 12px; }
.footer-grid ul { list-style: none; margin: 0; padding: 0; display: grid; gap: 8px; }
.footer-grid a { color: var(--ink-2); text-decoration: none; }
.footer-grid a:hover { color: var(--accent); text-decoration: underline; }
.footer-grid p { color: var(--muted); margin: 12px 0 0; max-width: 34ch; }
.footer-bottom { margin-top: 36px; padding-top: 20px; border-top: 1px solid var(--line); color: var(--muted); font-size: 14px; display: flex; flex-wrap: wrap; gap: 8px 24px; justify-content: space-between; }
@media (max-width: 860px) { .footer-grid { grid-template-columns: 1fr 1fr; } }
@media (max-width: 520px) { .footer-grid { grid-template-columns: 1fr; } }

/* ---------- Search ---------- */
.search {
  position: fixed; inset: 0; z-index: 90; background: rgba(8, 12, 28, .55); backdrop-filter: blur(4px);
  display: flex; justify-content: center; align-items: flex-start; padding: 9vh 16px 16px;
}
.search[hidden] { display: none; }
.search-panel { width: 100%; max-width: 640px; background: var(--surface); border-radius: 18px; border: 1px solid var(--line); box-shadow: var(--shadow); overflow: hidden; }
.search-field { display: flex; align-items: center; gap: 12px; padding: 4px 18px; border-bottom: 1px solid var(--line); color: var(--muted); }
.search-field input { flex: 1; border: 0; outline: 0; background: transparent; font: inherit; font-size: 18px; color: var(--ink); padding: 16px 0; min-width: 0; }
.search-field kbd { font-family: var(--mono); font-size: 12px; border: 1px solid var(--line); border-radius: 6px; padding: 2px 6px; color: var(--muted); }
.search-results { list-style: none; margin: 0; padding: 8px; max-height: 55vh; overflow: auto; }
.search-results a { display: block; padding: 11px 14px; border-radius: 10px; text-decoration: none; color: var(--ink); }
.search-results a:hover, .search-results a.sel { background: var(--accent-soft); }
.search-results strong { display: block; font-size: 16px; }
.search-results span { display: block; font-size: 13.5px; color: var(--muted); margin-top: 2px; }
.search-empty { padding: 22px 18px; color: var(--muted); text-align: center; }

/* ---------- 404 ---------- */
.notfound { text-align: center; padding: 80px 0 40px; }
.notfound .big { font-size: clamp(72px, 16vw, 140px); font-weight: 900; letter-spacing: -.05em; color: var(--accent); line-height: 1; }
.notfound p { color: var(--muted); font-size: 19px; max-width: 46ch; margin: 14px auto 26px; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { transition: none !important; }
}
@media print {
  .site-header, .site-footer, .toc-box, .related, .search { display: none !important; }
  body { background: #fff; color: #000; }
  .article { border: 0; box-shadow: none; padding: 0; }
}