:root {
  --bg: #fff;
  --wash: #f0f2f5;
  --ink: #08060d;
  --body: #1c2b33;
  --muted: #65686c;
  --line: #dadde1;
  --link: #0064e0;
  --link-press: #054c9e;
  --ember: #c3471d;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--body);
  background: var(--bg);
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  font-size: 15px;
  line-height: 1.55;
}

a { color: var(--link); text-decoration: none; }
a:hover { text-decoration: underline; }
a:active { color: var(--link-press); }

img { display: block; max-width: 100%; }

.top {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  min-height: 56px;
  padding: 0 20px;
  background: #fff;
  border-bottom: 1px solid var(--line);
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--ink);
  text-decoration: none;
  font-weight: 650;
  font-size: 17px;
}
.brand:hover { text-decoration: none; }
.brand img {
  width: 28px;
  height: 28px;
  border-radius: 6px;
}
.brand small {
  color: var(--muted);
  font-weight: 500;
  font-size: 15px;
}

.top nav {
  display: flex;
  gap: 18px;
  font-size: 14px;
  font-weight: 600;
}
.top nav a { color: var(--body); }
.top nav a[aria-current="page"] { color: var(--link); }

.frame {
  display: grid;
  grid-template-columns: 280px minmax(0, 1fr);
  max-width: 1120px;
  margin: 0 auto;
}

.rail {
  position: sticky;
  top: 56px;
  height: calc(100vh - 56px);
  overflow: auto;
  padding: 22px 12px 40px 16px;
  border-right: 1px solid var(--line);
  background: #fff;
}
.rail p {
  margin: 0 12px 10px;
  color: var(--muted);
  font-size: 13px;
  font-weight: 650;
  letter-spacing: 0.02em;
  text-transform: uppercase;
}
.rail a {
  display: block;
  padding: 8px 12px;
  border-left: 3px solid transparent;
  color: var(--body);
  font-size: 14px;
  line-height: 1.35;
}
.rail a:hover { background: var(--wash); text-decoration: none; }
.rail a.is-on {
  border-left-color: var(--link);
  color: var(--ink);
  font-weight: 650;
}

.page {
  min-width: 0;
  padding: 28px 40px 80px;
}

h1 {
  margin: 0 0 8px;
  color: var(--ink);
  font-size: 32px;
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.15;
}

.updated {
  margin: 0 0 22px;
  color: var(--muted);
  font-size: 13px;
}

h2 {
  margin: 36px 0 12px;
  color: var(--ink);
  font-size: 22px;
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.25;
  scroll-margin-top: 76px;
}

h3 {
  margin: 22px 0 8px;
  color: var(--ink);
  font-size: 17px;
  font-weight: 650;
}

p { margin: 0 0 12px; }
ul, ol { margin: 0 0 12px; padding-left: 22px; }
li { margin: 0 0 6px; }

.box {
  margin: 16px 0 20px;
  padding: 16px 18px;
  background: var(--wash);
  border-radius: 8px;
}
.box strong {
  display: block;
  margin-bottom: 6px;
  color: var(--ink);
  font-size: 13px;
}

.control {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 16px 0 8px;
}
.control a {
  display: inline-block;
  padding: 8px 12px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  color: var(--ink);
  font-weight: 650;
  font-size: 14px;
}
.control a:hover { background: var(--wash); text-decoration: none; }

.list-block {
  margin: 12px 0 16px;
  border: 1px solid var(--line);
  border-radius: 8px;
  overflow: hidden;
}
.list-block div {
  padding: 12px 14px;
  border-top: 1px solid var(--line);
}
.list-block div:first-child { border-top: 0; }
.list-block b {
  display: block;
  margin-bottom: 4px;
  color: var(--ink);
}

.help {
  display: grid;
  gap: 0;
  border: 1px solid var(--line);
  border-radius: 8px;
  overflow: hidden;
}
.help article {
  padding: 16px 18px;
  border-top: 1px solid var(--line);
}
.help article:first-child { border-top: 0; }
.help h2 { margin: 0 0 8px; font-size: 17px; }

.foot {
  max-width: 1120px;
  margin: 0 auto;
  padding: 18px 20px 28px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 13px;
}
.foot nav { display: flex; gap: 14px; flex-wrap: wrap; margin-top: 8px; }
.foot a { color: var(--muted); }

@media (max-width: 860px) {
  .frame { grid-template-columns: 1fr; }
  .rail {
    position: relative;
    top: 0;
    height: auto;
    padding: 16px 16px 8px;
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }
  .page { padding: 22px 16px 64px; }
  h1 { font-size: 26px; }
}

@media print {
  .top, .rail, .foot, .control { display: none; }
  .frame { display: block; }
  .page { padding: 0; }
}