:root {
  --ink: #1c2833;
  --muted: #5c6b7a;
  --line: #d5dee6;
  --paper: #f4f7f8;
  --card: #ffffff;
  --brand: #0f5c6b;
  --brand-dark: #0a3d47;
  --accent: #1a7f8e;
  --sidebar: 260px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font: 17px/1.6 "Segoe UI", "Helvetica Neue", Arial, sans-serif;
}

.nav-toggle { display: none; }

.layout {
  display: flex;
  min-height: 100vh;
}

.sidebar {
  width: var(--sidebar);
  flex: 0 0 var(--sidebar);
  background: var(--brand-dark);
  color: #e7f3f5;
  position: sticky;
  top: 0;
  height: 100vh;
  overflow: auto;
  padding: 1.4rem 1rem 2rem;
}

.brand-kicker {
  margin: 0;
  font-size: 0.75rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: #9fd4dc;
}

.brand-name {
  margin: 0.15rem 0 1.2rem;
  font-size: 1.55rem;
  font-weight: 700;
  color: #fff;
}

.sidebar a {
  display: block;
  color: #d7ebee;
  text-decoration: none;
  padding: 0.45rem 0.7rem;
  border-radius: 6px;
  margin-bottom: 0.15rem;
}

.sidebar a:hover,
.sidebar a.active {
  background: rgba(255, 255, 255, 0.12);
  color: #fff;
}

.sidebar details.nav-group {
  margin-bottom: 0.15rem;
}

.sidebar summary.nav-link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.6rem;
  list-style: none;
  cursor: pointer;
  color: #d7ebee;
  padding: 0.45rem 0.7rem;
  border-radius: 6px;
}

.sidebar summary.nav-link::-webkit-details-marker {
  display: none;
}

.sidebar summary.nav-link::marker {
  content: "";
}

.sidebar summary.nav-link::after {
  content: "";
  width: 0.42rem;
  height: 0.42rem;
  border-right: 2px solid currentColor;
  border-bottom: 2px solid currentColor;
  transform: rotate(45deg);
  margin-right: 0.15rem;
  flex: 0 0 auto;
  opacity: 0.85;
}

.sidebar details[open] > summary.nav-link::after {
  transform: rotate(-135deg);
  margin-top: 0.25rem;
}

.sidebar summary.nav-link:hover,
.sidebar summary.nav-link.active {
  background: rgba(255, 255, 255, 0.12);
  color: #fff;
}

.sidebar .nav-sub a {
  padding-left: 1.35rem;
  font-size: 0.92rem;
  color: #b7d4da;
}

.content {
  flex: 1;
  min-width: 0;
}

.top {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 0.8rem 1.6rem;
  background: var(--card);
  border-bottom: 1px solid var(--line);
  position: sticky;
  top: 0;
  z-index: 2;
}

.menu-btn {
  display: none;
  cursor: pointer;
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 0.25rem 0.7rem;
  font-size: 0.9rem;
}

.crumb {
  margin: 0;
  color: var(--muted);
  font-size: 0.9rem;
}

article {
  max-width: 820px;
  margin: 0 auto;
  padding: 2rem 1.4rem 4rem;
}

h1 {
  font-size: 2rem;
  line-height: 1.2;
  margin: 0 0 0.6rem;
}

h2 {
  font-size: 1.35rem;
  margin: 2.2rem 0 0.6rem;
  padding-top: 0.4rem;
}

h3 {
  font-size: 1.08rem;
  margin: 1.4rem 0 0.4rem;
}

p { margin: 0.6rem 0; }

.lead {
  font-size: 1.12rem;
  color: #33414c;
}

a { color: var(--accent); }

ul, ol { padding-left: 1.3rem; }

li { margin: 0.28rem 0; }

.card-list {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.8rem;
  margin: 1rem 0 0.4rem;
  padding: 0;
  list-style: none;
}

.card-list a {
  display: block;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 0.8rem 0.95rem;
  text-decoration: none;
  color: var(--ink);
}

.card-list a strong { display: block; color: var(--brand); }

.card-list a span {
  display: block;
  color: var(--muted);
  font-size: 0.92rem;
  margin-top: 0.15rem;
}

table {
  width: 100%;
  border-collapse: collapse;
  background: var(--card);
  margin: 0.8rem 0 1rem;
  font-size: 0.95rem;
}

th, td {
  border: 1px solid var(--line);
  padding: 0.45rem 0.6rem;
  text-align: left;
  vertical-align: top;
}

th { background: #e7f1f3; }

.note {
  background: #eef6f7;
  border-left: 4px solid var(--brand);
  padding: 0.7rem 0.9rem;
  margin: 1rem 0;
}

figure {
  margin: 1.2rem 0;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 8px;
  overflow: hidden;
}

figure img {
  display: block;
  width: 100%;
  height: auto;
}

figcaption {
  padding: 0.55rem 0.8rem 0.7rem;
  color: var(--muted);
  font-size: 0.88rem;
}

code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 0.9em;
  background: #e8eef0;
  padding: 0.05rem 0.3rem;
  border-radius: 4px;
}

@media (max-width: 860px) {
  .sidebar {
    position: fixed;
    z-index: 5;
    transform: translateX(-105%);
    transition: transform 0.2s ease;
  }

  .nav-toggle:checked ~ .layout .sidebar {
    transform: translateX(0);
  }

  .menu-btn { display: inline-block; }

  .card-list { grid-template-columns: 1fr; }

  article { padding-top: 1.2rem; }
}

@media print {
  .sidebar, .top, .menu-btn { display: none !important; }
  .layout { display: block; }
  article { max-width: none; }
  body { background: #fff; }
  a { color: inherit; text-decoration: none; }
}