:root {
  --bg: #fff;
  --surface: #f8f9fa;
  --text: #202122;
  --muted: #54595d;
  --link: #36c;
  --border: #a2a9b1;
  --soft-border: #c8ccd1;
  --active: #eaecf0;
}
html[data-theme="dark"] {
  --bg: #181a1b;
  --surface: #222526;
  --text: #eaecf0;
  --muted: #b8bbbe;
  --link: #8ab4f8;
  --border: #72777d;
  --soft-border: #3d4145;
  --active: #303336;
}
* { box-sizing: border-box; }
html {
  background: var(--bg);
  scroll-behavior: smooth;
  scroll-padding-top: 75px;
}
[id] {
  scroll-margin-top: 75px;
}
body {
  margin: 0;
  color: var(--text);
  background: var(--bg);
  font-family: Georgia, "Times New Roman", serif;
  font-size: 15px;
  line-height: 1.6;
}
button, .site-header, .sidebar, .page-tools, .toc, .notice, figcaption, .footer, summary {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
}
a { color: var(--link); text-decoration: none; }
a:hover { text-decoration: underline; }
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  min-height: 56px;
  height: 57px;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 0 22px;
  background: var(--bg);
}
.menu-button, .theme-button {
  border: 1px solid var(--soft-border);
  background: var(--surface);
  color: var(--text);
  padding: 6px;
  cursor: pointer;
  font-size: 13px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 4px;
  transition: background-color 0.2s, border-color 0.2s;
  line-height: 1;
}
.menu-button svg {
  width: 18px;
  height: 18px;
  display: block;
}
.theme-button svg {
  width: 16px;
  height: 16px;
  display: block;
}
.theme-button .sun-icon {
  display: none;
}
.theme-button .moon-icon {
  display: block;
}
html[data-theme="dark"] .theme-button .sun-icon {
  display: block;
}
html[data-theme="dark"] .theme-button .moon-icon {
  display: none;
}
.wordmark {
  font-family: Georgia, "Times New Roman", serif;
  color: var(--text);
  font-size: 19px;
}
.tagline { color: var(--muted); font-size: 13px; }
.header-tools { margin-left: auto; }
.site-shell { display: flex; min-height: calc(100vh - 57px); }
.sidebar {
  position: sticky;
  top: 57px;
  height: calc(100vh - 57px);
  align-self: flex-start;
  width: 275px;
  flex: 0 0 275px;
  border-right: 1px solid var(--soft-border);
  padding: 18px 16px 28px;
  background: var(--surface);
  overflow-y: auto;
}
html[data-sidebar="hidden"] .sidebar,
.sidebar.hidden { display: none !important; }
.sidebar-section { margin-bottom: 24px; }
.sidebar-title {
  font-size: 12px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .03em;
  color: var(--muted);
  margin: 0 0 6px 8px;
}
.sidebar a, .sidebar summary {
  display: block;
  padding: 3px 8px;
  font-size: 13px;
}
.sidebar details { margin: 0; }
.sidebar summary { cursor: pointer; list-style-position: inside; color: var(--text); }
.sidebar summary::marker { color: var(--muted); }
.sidebar .summary-link { color: var(--link); display: inline; padding: 0; }
.sidebar .nested { margin-left: 11px; border-left: 1px solid var(--soft-border); }
.nav-children { margin-left: 18px; border-left: 1px solid var(--soft-border); padding-left: 7px; }
.nav-children a { padding: 2px 7px; }
.nav-children a.active { background: var(--active); font-weight: 600; }
.content { width: 100%; max-width: 1180px; padding: 16px 38px 48px; }
.page-tools {
  border-bottom: 1px solid var(--soft-border);
  color: var(--muted);
  font-size: 12px;
  padding: 0 0 8px;
  margin-bottom: 24px;
}
.article-kicker { color: var(--muted); font-size: 13px; margin-bottom: 3px; }
h1 {
  font-family: Georgia, "Times New Roman", serif;
  font-weight: 400;
  font-size: 34px;
  line-height: 1.2;
  margin: 0 0 5px;
  border-bottom: 1px solid var(--border);
  padding-bottom: 8px;
}
h2 {
  font-size: 23px;
  font-weight: 400;
  border-bottom: 1px solid var(--soft-border);
  padding-bottom: 4px;
  margin-top: 30px;
}
h3 { font-size: 18px; font-weight: 600; margin-top: 22px; }
p { max-width: 920px; }
.lede { font-size: 16px; color: var(--muted); margin-top: 5px; }
.toc {
  border: 1px solid var(--border);
  background: var(--surface);
  width: max-content;
  min-width: 250px;
  padding: 10px 16px;
  margin: 18px 0 24px;
}
.toc-title { font-weight: 700; margin-bottom: 4px; }
.toc ol { margin: 0; padding-left: 23px; }
.notice {
  border: 1px solid var(--soft-border);
  background: var(--surface);
  padding: 10px 13px;
  margin: 18px 0;
  max-width: 930px;
}
table {
  border-collapse: collapse;
  margin: 18px 0;
  width: min(100%, 930px);
}
th, td {
  border: 1px solid var(--border);
  padding: 7px 9px;
  text-align: left;
  vertical-align: top;
}
th { background: var(--surface); font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; font-size: 13px; }
ul, ol { max-width: 900px; }
.graph-placeholder {
  margin: 22px 0;
  width: min(100%, 920px);
  border: 1px solid var(--border);
  background: var(--surface);
}
.graph-container {
  margin: 22px 0;
  width: min(100%, 960px);
  border: 1px solid var(--border);
  background: #ffffff;
  border-radius: 4px;
  overflow: hidden;
}
.graph-image {
  width: 100%;
  height: auto;
  display: block;
}
.graph-axis {
  height: 330px;
  position: relative;
  border-bottom: 1px solid var(--border);
  border-left: 1px solid var(--border);
  margin: 28px 35px 0 55px;
}
.graph-axis::before {
  content: "";
  position: absolute; inset: 25% 0 0 0;
  border-top: 1px dashed var(--soft-border);
  box-shadow: 0 82px 0 var(--soft-border);
}
.graph-empty {
  position: absolute; inset: 0;
  display: grid; place-items: center;
  color: var(--muted);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: 13px;
}
.axis-y, .axis-x {
  position: absolute;
  color: var(--muted);
  font: 12px -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}
.axis-y { left: -48px; top: 45%; transform: rotate(-90deg); }
.axis-x { right: 40%; bottom: -28px; }
figcaption { padding: 10px 13px; color: var(--muted); font-size: 12px; }
.footer {
  border-top: 1px solid var(--soft-border);
  margin-top: 48px;
  padding-top: 12px;
  color: var(--muted);
  font-size: 12px;
}
@media (max-width: 800px) {
  html, body {
    overflow-x: hidden;
  }
  .site-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    width: 100%;
    z-index: 100;
  }
  .site-shell {
    margin-top: 57px;
    overflow-x: hidden;
  }
  .sidebar {
    position: fixed;
    top: 57px;
    left: 0;
    height: calc(100vh - 57px);
    width: 275px;
    max-width: 80vw;
    flex: none;
    z-index: 90;
    box-shadow: 2px 0 8px rgba(0, 0, 0, 0.15);
  }
  .content {
    width: 100%;
    max-width: 100%;
    padding: 14px 18px 40px;
  }
  .tagline { display: none; }
  h1 { font-size: 28px; }
}