/* UDRP Perspectives — clean legal/academic design
   Zero dependencies. System font stacks; deep-navy accent on warm paper. */

:root {
  --paper:      #fbfaf7;
  --paper-2:    #f4f2ec;
  --ink:        #1c1b19;
  --ink-soft:   #4a4843;
  --ink-faint:  #78756e;
  --rule:       #e3ded3;
  --rule-soft:  #ece8df;
  --accent:     #223a5e;   /* deep navy */
  --accent-2:   #2f5688;
  --accent-ink: #16283f;
  --gold:       #9a7b3f;
  --sel:        #dfe6f0;
  --serif: "Iowan Old Style", "Palatino Linotype", Palatino, "Book Antiqua",
           Georgia, "Times New Roman", serif;
  --sans: system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --measure: 44rem;
  --topbar-h: 3.5rem;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; scroll-padding-top: calc(var(--topbar-h) + 1rem); }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--serif);
  font-size: 1.0625rem;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

::selection { background: var(--sel); }

a { color: var(--accent-2); text-underline-offset: 2px; text-decoration-thickness: 1px; }
a:hover { color: var(--accent-ink); }

.skip-link {
  position: absolute; left: -999px; top: 0; z-index: 100;
  background: var(--accent); color: #fff; padding: .6rem 1rem;
}
.skip-link:focus { left: .5rem; top: .5rem; }

/* ----------------------------------------------------------------- topbar */
.topbar {
  position: sticky; top: 0; z-index: 40;
  height: var(--topbar-h);
  display: flex; align-items: center; gap: 1rem;
  padding: 0 1.25rem;
  background: rgba(251, 250, 247, .92);
  backdrop-filter: saturate(1.1) blur(8px);
  border-bottom: 1px solid var(--rule);
}
.wordmark {
  text-decoration: none;
  display: flex;
  align-items: center;
  flex: none;
}
.wordmark img {
  height: 2.2rem;
  width: auto;
  display: block;
}
.menu-toggle {
  display: none;
  background: none; border: 1px solid var(--rule); border-radius: 6px;
  font-size: 1.1rem; color: var(--ink-soft);
  width: 2.3rem; height: 2.3rem; cursor: pointer;
}
.search { margin-left: auto; flex: 0 1 20rem; }
#search {
  width: 100%;
  font-family: var(--sans); font-size: .95rem;
  padding: .5rem .85rem;
  border: 1px solid var(--rule); border-radius: 8px;
  background: #fff; color: var(--ink);
}
#search:focus { outline: 2px solid var(--accent-2); outline-offset: 0; border-color: transparent; }
.archive-link {
  font-family: var(--sans); font-size: .85rem; letter-spacing: .03em;
  text-transform: uppercase; text-decoration: none; color: var(--ink-faint);
  white-space: nowrap;
}
.archive-link:hover { color: var(--accent); }

/* ----------------------------------------------------------------- layout */
.layout {
  display: grid;
  grid-template-columns: 20rem minmax(0, 1fr);
  align-items: start;
  max-width: 84rem;
  margin: 0 auto;
}

.sidebar {
  position: sticky; top: var(--topbar-h);
  height: calc(100vh - var(--topbar-h));
  overflow-y: auto;
  border-right: 1px solid var(--rule);
  background: var(--paper);
}
.sidebar-inner { padding: 1.5rem 1rem 4rem 1.5rem; }
.updated {
  font-family: var(--sans); font-size: .72rem; letter-spacing: .08em;
  text-transform: uppercase; color: var(--ink-faint);
  margin: 0 0 1rem;
}

.toc-section { margin-bottom: 1.25rem; }
.toc-section-title {
  display: block;
  font-family: var(--sans); font-size: .78rem; font-weight: 700;
  letter-spacing: .06em; text-transform: uppercase;
  color: var(--accent-ink); text-decoration: none;
  padding: .25rem 0; margin-bottom: .35rem;
  border-bottom: 1px solid var(--rule-soft);
}
.toc-section-title:hover { color: var(--accent); }
.toc-topics { list-style: none; margin: 0; padding: 0; }
.toc-topics a {
  display: flex; gap: .5rem;
  font-family: var(--sans); font-size: .86rem; line-height: 1.35;
  color: var(--ink-soft); text-decoration: none;
  padding: .28rem .5rem .28rem .4rem;
  border-radius: 6px;
  border-left: 2px solid transparent;
}
.toc-topics a:hover { background: var(--paper-2); color: var(--accent-ink); }
.toc-topics a.active {
  background: var(--sel); color: var(--accent-ink);
  border-left-color: var(--accent);
}
.toc-num { color: var(--ink-faint); font-variant-numeric: tabular-nums; flex: none; }
.toc-topics a.active .toc-num { color: var(--accent); }
.search-empty { font-family: var(--sans); font-size: .85rem; color: var(--ink-faint); padding: 0 .4rem; }

/* --------------------------------------------------------------- content */
.content {
  padding: 2.5rem clamp(1.25rem, 4vw, 3.5rem) 6rem;
  min-width: 0;
}
.content > * { max-width: var(--measure); }

.masthead { margin-bottom: 2.5rem; }
.masthead h1 {
  font-size: clamp(2.1rem, 4vw, 3rem);
  line-height: 1.1; margin: 0 0 .75rem;
  letter-spacing: -.01em; color: var(--accent-ink); font-weight: 600;
}
.masthead-meta { margin: .2rem 0; color: var(--ink-soft); font-size: 1rem; }

h2, h3 { color: var(--accent-ink); font-weight: 600; }

.welcome {
  background: var(--paper-2);
  border: 1px solid var(--rule);
  border-radius: 12px;
  padding: 1.75rem 2rem;
  margin-bottom: 3rem;
}
.welcome h2 { margin-top: 0; font-size: 1.5rem; }
.welcome p { color: var(--ink-soft); }

.welcome-more { margin-top: .75rem; }
.welcome-more > summary {
  cursor: pointer; list-style: none;
  font-family: var(--sans); font-size: .9rem;
  color: var(--accent-2);
  display: flex; align-items: center; gap: .45rem;
  padding: .2rem 0;
  user-select: none;
}
.welcome-more > summary::-webkit-details-marker { display: none; }
.welcome-more > summary::before {
  content: "+";
  font-size: 1.1rem; font-weight: 700; line-height: 1;
  width: 1rem; text-align: center; flex: none;
}
.welcome-more[open] > summary::before { content: "\2212"; }
.welcome-more > summary:hover { color: var(--accent-ink); }
.welcome-more p { color: var(--ink-soft); margin-top: .75rem; }

.topics-heading {
  font-size: .8rem; letter-spacing: .12em; text-transform: uppercase;
  font-family: var(--sans); color: var(--ink-faint); font-weight: 700;
  border-bottom: 1px solid var(--rule); padding-bottom: .6rem;
  margin: 0 0 2rem;
}

.section { margin-bottom: 3.5rem; scroll-margin-top: calc(var(--topbar-h) + 1rem); }
.section-title {
  font-size: 1.8rem; margin: 0 0 1.5rem;
  padding-bottom: .5rem; border-bottom: 2px solid var(--accent);
  color: var(--accent);
}

.topic {
  padding: 1.75rem 0;
  border-top: 1px solid var(--rule-soft);
  scroll-margin-top: calc(var(--topbar-h) + 1rem);
}
.topic:first-of-type { border-top: none; }
.topic-title {
  font-size: 1.35rem; line-height: 1.3; margin: 0 0 1rem;
  display: flex; align-items: baseline; gap: .5rem; flex-wrap: wrap;
  position: relative;
}
.topic-num {
  font-family: var(--sans); font-weight: 700; font-size: .95rem;
  color: #fff; background: var(--accent);
  padding: .1rem .5rem; border-radius: 5px;
  font-variant-numeric: tabular-nums; flex: none;
  align-self: center;
}
.anchor {
  position: absolute; left: -1.4rem; top: .15rem;
  color: var(--ink-faint); text-decoration: none; opacity: 0;
  font-family: var(--sans); transition: opacity .12s;
}
.topic-title:hover .anchor { opacity: 1; }
.anchor:hover { color: var(--accent); }
:target > .topic-title .topic-num,
.topic:target .topic-num { box-shadow: 0 0 0 3px var(--sel); }

.perspective p:first-child { margin-top: 0; }

/* highlight a freshly-targeted topic */
.topic:target { animation: flash 1.6s ease-out; }
@keyframes flash {
  from { background: #fff7e0; }
  to   { background: transparent; }
}

/* --------------------------------------------------- additional (details) */
.additional {
  margin-top: 1.25rem;
  border: 1px solid var(--rule);
  border-radius: 10px;
  background: #fff;
}
.additional > summary {
  cursor: pointer; list-style: none;
  font-family: var(--sans); font-size: .82rem; font-weight: 600;
  letter-spacing: .05em; text-transform: uppercase; color: var(--accent);
  padding: .8rem 1.1rem;
  display: flex; align-items: center; gap: .55rem;
}
.additional > summary::-webkit-details-marker { display: none; }
.additional > summary::before {
  content: "+"; font-size: 1.1rem; line-height: 1;
  width: 1.1rem; text-align: center; color: var(--accent-2);
}
.additional[open] > summary::before { content: "\2212"; }
.additional[open] > summary { border-bottom: 1px solid var(--rule-soft); }
.additional-body { padding: 1rem 1.25rem 1.4rem; }
.additional-body > *:first-child { margin-top: 0; }

.subhead {
  font-family: var(--sans); font-size: .74rem; font-weight: 700;
  letter-spacing: .09em; text-transform: uppercase; color: var(--gold);
  margin: 1.6rem 0 .6rem;
  padding-bottom: .3rem; border-bottom: 1px solid var(--rule-soft);
}
.additional-body p {
  font-size: 1rem; color: var(--ink-soft);
  padding-left: .9rem; border-left: 2px solid var(--rule);
  margin: .7rem 0;
}
.additional-body blockquote {
  font-size: .97rem; color: var(--ink-soft);
  padding: .5rem .9rem; border-left: 3px solid var(--rule);
  margin: .4rem 0 .8rem 0; font-style: italic;
}
.additional-body ul { padding-left: 1.2rem; }
.additional-body li { font-size: .97rem; color: var(--ink-soft); margin: .3rem 0; }

/* ----------------------------------------------------------- misc / footer */
.to-top {
  position: fixed; right: 1.25rem; bottom: 1.25rem; z-index: 30;
  width: 2.75rem; height: 2.75rem; border-radius: 50%;
  border: 1px solid var(--rule); background: #fff; color: var(--accent);
  font-size: 1.2rem; cursor: pointer; box-shadow: 0 2px 8px rgba(0,0,0,.08);
}
.to-top:hover { background: var(--accent); color: #fff; }

.site-footer {
  border-top: 1px solid var(--rule);
  padding: 2rem 1.5rem; text-align: center;
  font-family: var(--sans); font-size: .85rem; color: var(--ink-faint);
}
.site-footer p { margin: .25rem 0; }

/* hidden topics during search */
.topic[hidden], .section[hidden], .toc-section[hidden],
.toc-topics li[hidden] { display: none !important; }

/* --------------------------------------------------------------- responsive */
@media (max-width: 900px) {
  .menu-toggle { display: inline-flex; align-items: center; justify-content: center; }
  .archive-link { display: none; }
  .layout { grid-template-columns: 1fr; }
  .sidebar {
    position: fixed; top: var(--topbar-h); left: 0; z-index: 35;
    width: min(20rem, 82vw); height: calc(100vh - var(--topbar-h));
    border-right: 1px solid var(--rule);
    box-shadow: 4px 0 24px rgba(0,0,0,.12);
    transform: translateX(-104%); transition: transform .22s ease;
  }
  .sidebar.open { transform: translateX(0); }
}

/* ----------------------------------------------- standalone section pages */
body.standalone .content { margin: 0 auto; }
body.standalone .menu-toggle { display: none !important; }

.section-nav {
  display: flex; gap: 1rem;
  margin-top: 2.5rem; padding-top: 1.5rem;
  border-top: 1px solid var(--rule);
  max-width: var(--measure);
}
.section-nav a {
  font-family: var(--sans); font-size: .88rem;
  color: var(--accent-2); text-decoration: none;
  padding: .45rem .9rem;
  border: 1px solid var(--rule); border-radius: 8px;
  max-width: 48%; white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}
.section-nav a:hover { background: var(--paper-2); color: var(--accent-ink); }
.section-nav .nav-next { margin-left: auto; }

/* ------------------------------------------------------------------ print */
@media print {
  .topbar, .sidebar, .to-top, .skip-link, .menu-toggle { display: none !important; }
  .layout { display: block; max-width: none; }
  .content { padding: 0; }
  .content > * { max-width: none; }
  body { font-size: 11pt; background: #fff; }
  .additional { border: none; }
  .additional > summary { display: none; }
  .additional[open] > summary, details.additional > summary { display: none; }
  details.additional { border: none; }
  details.additional > .additional-body { display: block !important; }
  details:not([open]) > .additional-body { display: block !important; }
  .welcome-more > summary { display: none; }
  details.welcome-more > p { display: block !important; }
  a { color: var(--ink); text-decoration: underline; }
}