*, *::before, *::after {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Roboto", sans-serif;
  font-size: 15px;
  line-height: 1.65;
  color: #1a1a1a;
  background: #fff;
}

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

.sidebar {
  width: 280px;
  min-width: 280px;
  background: #fafafa;
  border-right: 1px solid #e5e5e5;
  padding: 24px 0;
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  overflow-y: auto;
  z-index: 10;
}

.brand {
  padding: 0 20px 20px;
  border-bottom: 1px solid #e5e5e5;
  margin-bottom: 12px;
  font-size: 15px;
  font-weight: 700;
  letter-spacing: -0.01em;
}

.brand a {
  color: #1a1a1a;
  text-decoration: none;
}

.nav-sections {
  padding: 0;
}

.nav-section-title {
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: #999;
  padding: 8px 20px 4px;
  margin-top: 8px;
}

.nav-subsection-title {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  border: 0;
  background: transparent;
  text-align: left;
  font-size: 12px;
  font-weight: 700;
  color: #555;
  padding: 8px 20px 4px;
  cursor: pointer;
}

.nav-subsection-title::after {
  content: "▾";
  font-size: 11px;
  color: #999;
  transition: transform 0.15s ease;
}

.nav-subsection-title.is-collapsed::after {
  transform: rotate(-90deg);
}

.nav-subsection-title:hover {
  color: #1a1a1a;
}

.nav-tree {
  list-style: none;
  padding: 0;
  margin: 0;
}

.nav-tree li {
  margin: 0;
}

.nav-tree a {
  display: block;
  padding: 5px 20px 5px 36px;
  color: #555;
  text-decoration: none;
  font-size: 13px;
  line-height: 1.5;
  border-left: 3px solid transparent;
  transition: all 0.15s;
}

.nav-tree a:hover {
  color: #1a1a1a;
  background: #f0f0f0;
}

.nav-tree li.active a {
  color: #1a73e8;
  border-left-color: #1a73e8;
  background: #e8f0fe;
  font-weight: 500;
}

.content {
  margin-left: 280px;
  flex: 1;
  padding: 40px 56px 80px;
  max-width: 900px;
}

h1 {
  font-size: 28px;
  font-weight: 700;
  color: #1a1a1a;
  margin: 0 0 8px;
  letter-spacing: -0.02em;
}

h2 {
  font-size: 20px;
  font-weight: 700;
  color: #1a1a1a;
  margin: 40px 0 12px;
  letter-spacing: -0.01em;
}

h3 {
  font-size: 16px;
  font-weight: 600;
  color: #333;
  margin: 28px 0 8px;
}

h4 {
  font-size: 14px;
  font-weight: 600;
  color: #555;
  margin: 20px 0 6px;
}

p {
  margin: 0 0 14px;
}

strong {
  font-weight: 600;
}

blockquote {
  border-left: 3px solid #1a73e8;
  padding: 12px 16px;
  margin: 16px 0;
  background: #f8fafd;
  color: #333;
  font-style: italic;
}

ul, ol {
  margin: 0 0 14px;
  padding-left: 20px;
}

li {
  margin-bottom: 4px;
}

li ul, li ol {
  margin: 4px 0 4px;
}

table {
  width: 100%;
  border-collapse: collapse;
  margin: 16px 0 24px;
  font-size: 13px;
}

th {
  text-align: left;
  padding: 10px 12px;
  background: #f5f5f5;
  border-bottom: 2px solid #ddd;
  font-weight: 600;
  font-size: 12px;
  color: #555;
}

td {
  padding: 8px 12px;
  border-bottom: 1px solid #eee;
  vertical-align: top;
}

tr:hover td {
  background: #fafafa;
}

pre {
  background: #f5f5f5;
  border: 1px solid #e5e5e5;
  border-radius: 4px;
  padding: 16px;
  overflow-x: auto;
  font-size: 13px;
  line-height: 1.5;
  margin: 16px 0;
  font-family: "Roboto Mono", monospace;
}

code {
  font-family: "Roboto Mono", monospace;
  font-size: 13px;
  background: #f0f0f0;
  padding: 1px 5px;
  border-radius: 3px;
}

pre code {
  background: none;
  padding: 0;
}

a {
  color: #1a73e8;
}

@media (max-width: 900px) {
  .layout {
    display: block;
  }

  .sidebar {
    position: static;
    width: 100%;
    min-width: 0;
    height: auto;
  }

  .content {
    margin-left: 0;
    padding: 24px 20px 56px;
  }
}