/* A quiet reading companion to the project overview. */
.guide-page {
  --guide-ink: #1d1d1f;
  --guide-muted: #6e6e73;
  --guide-blue: #0071e3;
  --guide-line: #d2d2d7;
  --guide-surface: #f5f5f7;
  background: #fff;
  color: var(--guide-ink);
  font-family: -apple-system, BlinkMacSystemFont, "Helvetica Neue", "PingFang SC", sans-serif;
}
.guide-page .page-width { width: min(100% - 80px, 1200px); }
.guide-masthead { padding: 92px 0 80px; text-align: center; border-bottom: 1px solid var(--guide-line); }
.guide-masthead .section-index { color: var(--guide-muted); font-size: 14px; letter-spacing: .035em; }
.guide-masthead h1 { margin: 18px 0 0; font-family: inherit; font-size: clamp(44px, 5.5vw, 72px); line-height: 1.1; font-weight: 650; letter-spacing: -.045em; }
.guide-masthead > p { max-width: 720px; margin: 26px auto 0; color: var(--guide-muted); font-size: 20px; line-height: 1.65; letter-spacing: -.015em; text-wrap: pretty; }
.guide-layout { display: grid; grid-template-columns: 240px minmax(0, 1fr); align-items: start; gap: 68px; padding-top: 48px; padding-bottom: 120px; }
.guide-sidebar { position: sticky; top: 96px; max-height: calc(100dvh - 128px); padding: 0 12px 18px 0; overflow-y: auto; scrollbar-width: thin; scrollbar-color: #d2d2d7 transparent; }
.guide-search { position: relative; display: flex; align-items: center; gap: 9px; min-height: 46px; padding: 0 8px 0 13px; border: 1px solid transparent; border-radius: 12px; background: var(--guide-surface); transition: background-color 200ms, border-color 200ms, box-shadow 200ms; }
.guide-search > img { flex: none; width: 17px; height: 17px; opacity: .5; }
.guide-search:focus-within { background: #fff; border-color: var(--guide-blue); box-shadow: 0 0 0 3px #0071e31f; }
.guide-search input { width: 100%; min-width: 0; height: 44px; padding: 0; border: 0; outline: 0; background: transparent; color: var(--guide-ink); font: inherit; font-size: 13px; }
.guide-search input::placeholder { color: var(--guide-muted); opacity: 1; }
.guide-search input::-webkit-search-cancel-button { display: none; }
.guide-search button { width: 28px; height: 28px; min-height: 0; padding: 6px; border: 0; }
.guide-search button img { width: 14px; height: 14px; }
.guide-nav-label { display: flex; align-items: center; justify-content: space-between; gap: 15px; margin: 32px 10px 12px; color: var(--guide-muted); font-size: 11px; font-weight: 600; }
#guide-total { font-variant-numeric: tabular-nums; font-weight: 400; }
.guide-nav-group { margin-block: 3px; }
.guide-chapter-link { display: grid; grid-template-columns: 18px minmax(0, 1fr) 16px; align-items: baseline; gap: 9px; padding: 12px 10px; border-radius: 11px; color: var(--guide-ink); font-size: 13px; line-height: 1.55; font-weight: 500; transition: color 180ms, background-color 180ms; }
.guide-chapter-link:hover { background: var(--guide-surface); color: var(--guide-blue); }
.guide-chapter-link.is-active { background: #eaf3ff; color: var(--guide-blue); }
.guide-nav-number, .guide-nav-count { color: var(--guide-muted); font-size: 10px; font-variant-numeric: tabular-nums; font-weight: 400; }
.guide-nav-count { text-align: right; }
.guide-subnav { display: grid; padding: 8px 0 12px 37px; }
.guide-topics-label { margin: 16px 0 7px; color: var(--guide-ink); font-size: 11px; font-weight: 600; }
.guide-subnav a { display: block; padding: 7px 0 7px 12px; border-left: 1px solid #e8e8ed; color: var(--guide-muted); font-size: 12px; line-height: 1.55; transition: color 180ms, border-color 180ms; }
.guide-subnav a:hover, .guide-subnav a:focus-visible { color: var(--guide-blue); border-left-color: var(--guide-blue); }
.guide-subnav a.is-active { color: var(--guide-blue); border-left-color: var(--guide-blue); font-weight: 600; }
.guide-version { display: flex; flex-direction: column; gap: 10px; margin: 32px 10px 0; padding-top: 24px; border-top: 1px solid #e8e8ed; color: var(--guide-muted); font-size: 11px; line-height: 1.65; }
.guide-version strong { color: var(--guide-ink); font-size: 11px; font-weight: 600; }
.guide-version a { display: inline-flex; align-items: center; gap: 5px; align-self: start; color: var(--guide-blue); font-weight: 500; }
.guide-version img { width: 13px; height: 13px; }
.guide-reading { min-width: 0; }
.guide-controls { display: flex; justify-content: space-between; align-items: center; gap: 16px; min-height: 46px; margin-bottom: 44px; }
.guide-controls > p { margin: 0; color: var(--guide-muted); font-size: 12px; }
.guide-controls > div { display: flex; gap: 6px; }
.guide-controls button { min-height: 36px; padding: 7px 12px; border-color: transparent; border-radius: 999px; background: var(--guide-surface); color: var(--guide-ink); font-size: 11px; font-weight: 500; }
.guide-controls button:hover:not(:disabled) { background: #e8e8ed; }
.guide-controls button:disabled { opacity: .4; cursor: default; }
#guide-chapter-select { display: none; }
.guide-chapter-header { scroll-margin-top: 100px; }
.guide-chapter-header .section-index { color: var(--guide-muted); font-size: 12px; letter-spacing: .04em; }
.guide-chapter-header h2 { max-width: 850px; margin: 16px 0 20px; font-family: inherit; font-size: clamp(32px, 3.5vw, 46px); font-weight: 650; letter-spacing: -.035em; line-height: 1.15; overflow-wrap: anywhere; text-wrap: balance; }
.guide-chapter-subtitle { margin: 0 0 16px; color: var(--guide-ink); font-size: 19px; font-weight: 600; line-height: 1.5; letter-spacing: -.015em; }
.guide-chapter-lead { max-width: 780px; margin: 0; color: var(--guide-muted); font-size: 17px; line-height: 1.8; text-wrap: pretty; }
.guide-source-links { display: flex; flex-wrap: wrap; gap: 18px; margin-top: 23px; }
.guide-source { display: inline-flex; align-items: center; gap: 6px; color: var(--guide-blue); font-size: 12px; line-height: 1.6; font-weight: 500; }
.guide-source img { flex: none; width: 14px; height: 14px; }
.guide-source:hover, .guide-permalink:hover { text-decoration: underline; text-underline-offset: 3px; }
.guide-chapter-flow { display: grid; grid-template-columns: minmax(0, 1fr) 19px minmax(0, 1fr) 19px minmax(0, 1fr); align-items: center; gap: 16px; margin: 32px 0 0; padding: 26px; border-radius: 20px; background: var(--guide-surface); color: var(--guide-ink); font-size: 14px; font-weight: 600; line-height: 1.6; }
.guide-chapter-flow img { width: 19px; height: 19px; opacity: .5; }
.guide-chapter-flow > span:not(:first-child) { text-align: center; }
.mechanism-entry { border-bottom: 1px solid var(--guide-line); scroll-margin-top: 100px; }
.mechanism-summary { display: grid; grid-template-columns: 42px minmax(0, 1fr) 32px; align-items: start; gap: 16px; padding: 34px 0; list-style: none; cursor: pointer; }
.mechanism-summary::-webkit-details-marker { display: none; }
.mechanism-summary:focus-visible { outline-offset: 6px; border-radius: 8px; }
.mechanism-entry-number { padding-top: 7px; color: var(--guide-muted); font-size: 11px; font-variant-numeric: tabular-nums; transition: color 180ms; }
.mechanism-entry.is-current .mechanism-entry-number { color: var(--guide-blue); }
.mechanism-summary-copy h3 { margin: 0; color: var(--guide-ink); font-size: 24px; font-weight: 600; letter-spacing: -.025em; line-height: 1.35; }
.mechanism-summary-copy p { max-width: 740px; margin: 12px 0 0; color: var(--guide-muted); font-size: 15px; line-height: 1.7; text-wrap: pretty; }
.entry-indicator { display: grid; place-items: center; width: 32px; height: 32px; margin-top: 1px; border-radius: 50%; background: var(--guide-surface); color: var(--guide-muted); transition: background-color 180ms, transform 300ms cubic-bezier(.22, 1, .36, 1); }
.entry-indicator img { width: 15px; height: 15px; }
.mechanism-summary:hover .entry-indicator { background: #e8e8ed; transform: scale(1.07); }
.entry-collapse, details[open] .entry-expand { display: none; }
details[open] .entry-collapse { display: block; }
.mechanism-entry-body { padding: 0 48px 36px 58px; }
.mechanism-process { margin: 0; color: var(--guide-ink); font-size: 16px; line-height: 1.9; overflow-wrap: anywhere; }
.mechanism-steps { display: grid; gap: 22px; padding: 0; margin: 0; list-style: none; }
.mechanism-steps li { display: grid; grid-template-columns: 30px minmax(0, 1fr); gap: 12px; }
.mechanism-steps .step-label { color: var(--guide-blue); font: 11px/2.7 ui-monospace, SFMono-Regular, Menlo, monospace; }
.mechanism-explanation { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 28px; margin: 28px 0 24px; padding: 24px; border-radius: 18px; background: var(--guide-surface); }
.mechanism-explanation dt { margin-bottom: 8px; color: var(--guide-ink); font-size: 12px; line-height: 1.6; font-weight: 600; }
.mechanism-explanation dd { margin: 0; color: var(--guide-muted); font-size: 14px; line-height: 1.8; overflow-wrap: anywhere; }
.mechanism-scope { display: grid; grid-template-columns: 64px minmax(0, 1fr); gap: 16px; color: var(--guide-muted); font-size: 13px; line-height: 1.8; }
.mechanism-scope p { margin: 0; overflow-wrap: anywhere; }
.scope-label { padding-top: 1px; color: var(--guide-ink); font-size: 11px; font-weight: 500; }
.entry-references { display: flex; justify-content: space-between; align-items: baseline; flex-wrap: wrap; gap: 14px; margin-top: 24px; }
.guide-permalink { color: var(--guide-muted); font-size: 11px; }
.guide-chapter-pagination { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 32px; margin-top: 40px; }
.guide-chapter-pagination > a { display: flex; align-items: center; gap: 12px; color: var(--guide-blue); font-size: 13px; line-height: 1.7; }
.guide-chapter-pagination > a:last-child { justify-content: end; text-align: right; }
.guide-chapter-pagination img { width: 17px; height: 17px; flex: none; }
.guide-search-group + .guide-search-group { margin-top: 56px; }
.guide-search-group .guide-chapter-header h2 { font-size: 28px; }
.guide-search-group .guide-chapter-header { padding-bottom: 12px; border-bottom: 1px solid var(--guide-line); }
.guide-empty { padding: 72px 24px; border-radius: 24px; background: var(--guide-surface); color: var(--guide-muted); font-size: 16px; line-height: 1.8; text-align: center; }
@media (max-width: 1100px) {
  .guide-layout { grid-template-columns: 215px minmax(0, 1fr); gap: 36px; }
  .guide-sidebar { padding-right: 4px; }
  .mechanism-entry-body { padding-right: 0; }
  .guide-masthead { padding-block: 76px 64px; }
}
@media (max-width: 820px) {
  .guide-layout { display: block; padding-top: 32px; }
  .guide-sidebar { position: static; max-height: none; padding: 0 0 30px; border-bottom: 1px solid var(--guide-line); overflow: visible; }
  .guide-search { max-width: 460px; }
  .guide-nav-label { margin: 24px 4px 12px; }
  #guide-nav { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 6px; }
  .guide-nav-group { margin: 0; }
  .guide-chapter-link { height: 100%; align-content: start; padding: 12px 10px; }
  .guide-subnav, .guide-version { display: none; }
  .guide-reading { margin-top: 24px; }
  .guide-controls { position: sticky; z-index: 10; top: 64px; display: grid; grid-template-columns: minmax(0, 1fr) auto; gap: 12px; margin: 0 -12px 36px; padding: 14px 12px; border-bottom: 1px solid #e8e8ed; background: rgba(255, 255, 255, .94); backdrop-filter: blur(20px); -webkit-backdrop-filter: blur(20px); }
  #guide-chapter-select { display: block; grid-column: 1 / -1; width: 100%; min-width: 0; min-height: 42px; padding: 8px 12px; border: 1px solid var(--guide-line); border-radius: 10px; background: #fff; color: var(--guide-ink); font: inherit; font-size: 13px; }
  .mechanism-entry, .guide-chapter-header { scroll-margin-top: 196px; }
}
@media (max-width: 600px) {
  .guide-page .page-width { width: calc(100% - 40px); }
  .guide-masthead { padding: 54px 0 44px; }
  .guide-masthead .section-index { font-size: 12px; }
  .guide-masthead h1 { margin-top: 16px; font-size: 42px; line-height: 1.1; }
  .guide-masthead > p { margin-top: 22px; font-size: 17px; line-height: 1.65; }
  .guide-controls { grid-template-columns: minmax(0, 1fr); gap: 9px; }
  .guide-controls > p { position: absolute; width: 1px; height: 1px; overflow: hidden; clip-path: inset(50%); }
  .guide-controls > div { justify-content: space-between; }
  #guide-nav { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 6px; }
  .guide-chapter-link { grid-template-columns: 16px minmax(0, 1fr) 13px; gap: 6px; padding: 12px 9px; font-size: 12px; }
  .guide-nav-number, .guide-nav-count { font-size: 9px; }
  .guide-chapter-header h2 { font-size: 32px; line-height: 1.2; }
  .guide-chapter-subtitle { font-size: 18px; }
  .guide-chapter-lead { font-size: 16px; line-height: 1.8; }
  .guide-chapter-flow { grid-template-columns: minmax(0, 1fr) 13px minmax(0, 1fr) 13px minmax(0, 1fr); gap: 8px; padding: 22px 16px; font-size: 12px; }
  .guide-chapter-flow img { width: 13px; height: 13px; }
  .mechanism-summary { grid-template-columns: 31px minmax(0, 1fr) 28px; gap: 10px; padding-block: 27px; }
  .mechanism-entry-number { padding-top: 5px; font-size: 10px; }
  .mechanism-summary-copy h3 { font-size: 21px; line-height: 1.4; }
  .mechanism-summary-copy p { margin-top: 9px; font-size: 14px; }
  .entry-indicator { width: 28px; height: 28px; }
  .entry-indicator img { width: 13px; height: 13px; }
  .mechanism-entry-body { padding-left: 0; padding-bottom: 30px; }
  .mechanism-process { font-size: 16px; line-height: 1.85; }
  .mechanism-explanation { grid-template-columns: minmax(0, 1fr); gap: 20px; margin-block: 24px; padding: 22px; }
  .mechanism-explanation dt { margin-bottom: 6px; }
  .mechanism-explanation dd { font-size: 14px; }
  .mechanism-scope { grid-template-columns: minmax(0, 1fr); gap: 5px; }
  .guide-chapter-pagination { gap: 20px; }
  .guide-chapter-pagination > a { font-size: 12px; }
  .guide-layout { padding-bottom: 72px; }
}
@media (max-width: 360px) {
  .guide-masthead h1 { font-size: 38px; }
  .guide-chapter-link { grid-template-columns: 14px minmax(0, 1fr); gap: 5px; padding-inline: 7px; }
  .guide-nav-count { display: none; }
  .mechanism-summary { grid-template-columns: 27px minmax(0, 1fr) 26px; gap: 8px; }
  .mechanism-summary-copy h3 { font-size: 20px; }
  .guide-chapter-header h2 { font-size: 30px; }
}
@media (prefers-reduced-motion: reduce) {
  .guide-chapter-link, .guide-subnav a, .guide-search, .mechanism-entry-number, .entry-indicator { transition: none; }
  .mechanism-summary:hover .entry-indicator { transform: none; }
}