:root {
  --nv-green: #ec4899;
  --nv-green-dark: #be185d;
  --bg: #ffffff;
  --bg-sidebar: #f6f8f6;
  --bg-code: #f4f6f4;
  --text: #1a1a1a;
  --text-muted: #5a5f5a;
  --border: #e2e6e2;
  --link: #db2777;
  --sidebar-w: 290px;
  --toc-w: 240px;
  --header-h: 56px;
}

[data-theme="dark"] {
  --bg: #14181a;
  --bg-sidebar: #1b2023;
  --bg-code: #1e2427;
  --text: #e6e9e6;
  --text-muted: #9aa39a;
  --border: #2c3438;
  --link: #f472b6;
}

* { box-sizing: border-box; }

/* ---------- a11y skip link + reading progress ---------- */
.skip-link {
  position: fixed; top: -50px; left: 12px; z-index: 400;
  background: var(--nv-green); color: #fff; padding: 8px 14px;
  border-radius: 0 0 8px 8px; font-size: 13px; transition: top 0.15s;
}
.skip-link:focus { top: 0; text-decoration: none; }
.progress {
  position: fixed; top: 0; left: 0; height: 3px; width: 0;
  background: linear-gradient(90deg, var(--nv-green), #f9a8d4);
  z-index: 150; transition: width 0.08s linear;
}
:focus-visible { outline: 2px solid var(--nv-green); outline-offset: 2px; border-radius: 3px; }

/* ---------- i18n language toggle ---------- */
[data-lang="en"] .zh { display: none; }
[data-lang="zh"] .en { display: none; }
.lang-toggle { font-weight: 700; font-size: 13px; letter-spacing: 0.02em; }

html { scroll-behavior: smooth; scroll-padding-top: calc(var(--header-h) + 12px); }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  font-size: 16px;
  line-height: 1.65;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}

a { color: var(--link); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ---------- Header ---------- */
header.topbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--header-h);
  background: var(--bg);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 0 20px;
  z-index: 100;
}
.brand {
  display: flex; align-items: center; gap: 10px;
  font-weight: 700; font-size: 17px; color: var(--text);
}
.brand:hover { text-decoration: none; }
.brand .logo {
  width: 30px; height: 30px; border-radius: 6px;
  background: var(--nv-green);
  display: grid; place-items: center;
  color: #fff; font-weight: 800; font-size: 15px;
}
.brand .ver {
  font-size: 12px; font-weight: 600; color: #fff;
  background: var(--nv-green); padding: 2px 8px; border-radius: 20px;
  margin-left: 4px;
}
.topbar .search {
  flex: 1; max-width: 420px; margin-left: auto; position: relative;
}
.brand .logo {
  background: none; padding: 0; line-height: 0;
}
.brand .logo svg { display: block; }
.kbd-hint {
  position: absolute; right: 10px; top: 50%; transform: translateY(-50%);
  font-size: 11px; font-family: inherit; color: var(--text-muted);
  border: 1px solid var(--border); border-radius: 5px; padding: 1px 6px;
  background: var(--bg); pointer-events: none;
}
.topbar .search input:focus ~ .kbd-hint { display: none; }
.search-results {
  display: none; position: absolute; top: 44px; left: 0; right: 0;
  background: var(--bg); border: 1px solid var(--border);
  border-radius: 10px; box-shadow: 0 12px 32px rgba(0,0,0,0.15);
  max-height: 70vh; overflow-y: auto; z-index: 200; padding: 6px;
}
.search-results.open { display: block; }
.sr-item { display: block; padding: 9px 12px; border-radius: 8px; }
.sr-item:hover, .sr-item.sel { background: rgba(236,72,153,0.14); text-decoration: none; }
.sr-title { font-weight: 600; color: var(--nv-green-dark); font-size: 14px; }
[data-theme="dark"] .sr-title { color: var(--nv-green); }
.sr-snip { font-size: 12.5px; color: var(--text-muted); margin-top: 2px; line-height: 1.45; }
.sr-snip mark { background: rgba(236,72,153,0.28); color: inherit; padding: 0 1px; border-radius: 2px; }
.sr-empty { padding: 14px; color: var(--text-muted); font-size: 14px; text-align: center; }
.sr-sec { font-size: 11px; font-weight: 600; color: var(--text-muted);
  background: var(--bg-sidebar); border: 1px solid var(--border);
  padding: 1px 7px; border-radius: 20px; margin-left: 8px; white-space: nowrap; }
.sr-foot { display: flex; justify-content: space-between; gap: 10px;
  padding: 7px 12px 4px; margin-top: 4px; border-top: 1px solid var(--border);
  font-size: 11px; color: var(--text-muted); }
.topbar .search input {
  width: 100%; padding: 7px 12px;
  border: 1px solid var(--border); border-radius: 8px;
  background: var(--bg-sidebar); color: var(--text);
  font-size: 14px;
}
.topbar .search input:focus { outline: 2px solid var(--nv-green); border-color: transparent; }
.icon-btn {
  background: none; border: 1px solid var(--border);
  border-radius: 8px; width: 36px; height: 36px;
  cursor: pointer; color: var(--text); font-size: 16px;
}
.icon-btn:hover { border-color: var(--nv-green); }
.menu-toggle { display: none; }

/* ---------- Layout ---------- */
.layout { display: flex; padding-top: var(--header-h); }

nav.sidebar {
  width: var(--sidebar-w);
  flex-shrink: 0;
  position: sticky;
  top: var(--header-h);
  height: calc(100vh - var(--header-h));
  overflow-y: auto;
  background: var(--bg-sidebar);
  border-right: 1px solid var(--border);
  padding: 22px 14px 60px;
}
.sidebar .caption {
  display: flex; align-items: center; justify-content: space-between;
  width: 100%; background: none; border: none; cursor: pointer; font: inherit;
  font-size: 11px; font-weight: 700; text-transform: uppercase;
  letter-spacing: 0.08em; color: var(--nv-green-dark);
  margin: 16px 0 6px; padding: 4px 10px; border-radius: 6px;
}
.sidebar .caption:hover { background: rgba(236,72,153,0.08); }
[data-theme="dark"] .sidebar .caption { color: var(--nv-green); }
.sidebar .caption .chev { font-size: 15px; opacity: 0.55; transition: transform 0.15s; }
.nav-group:not(.collapsed) .caption .chev { transform: rotate(90deg); }
.nav-group.collapsed ul { display: none; }
.sidebar ul { list-style: none; margin: 0; padding: 0; }
.sidebar li a {
  display: block; padding: 5px 10px; border-radius: 6px;
  color: var(--text); font-size: 14px;
}
.sidebar li a:hover { background: rgba(236,72,153,0.12); text-decoration: none; }
.sidebar li a.active {
  background: rgba(236,72,153,0.18); color: var(--nv-green-dark);
  font-weight: 600;
}
[data-theme="dark"] .sidebar li a.active { color: var(--nv-green); }

main {
  flex: 1; min-width: 0;
  padding: 36px 48px 80px;
  max-width: 860px;
}

aside.toc {
  width: var(--toc-w); flex-shrink: 0;
  position: sticky; top: var(--header-h);
  height: calc(100vh - var(--header-h));
  overflow-y: auto;
  padding: 30px 18px;
  font-size: 13px;
}
aside.toc .toc-title {
  font-weight: 700; font-size: 11px; text-transform: uppercase;
  letter-spacing: 0.08em; color: var(--text-muted); margin-bottom: 8px;
}
aside.toc ul { list-style: none; margin: 0; padding: 0; }
aside.toc a { display: block; padding: 3px 0 3px 10px;
  border-left: 2px solid var(--border); color: var(--text-muted); }
aside.toc a:hover { color: var(--nv-green-dark); border-color: var(--nv-green); }
aside.toc a.active { color: var(--nv-green-dark); border-color: var(--nv-green);
  border-left-width: 2px; font-weight: 600; }
[data-theme="dark"] aside.toc a.active { color: var(--nv-green); }

/* heading hover anchors */
main h2 .anchor, main h3 { position: relative; }
main h2, main h3 { scroll-margin-top: 70px; }
.anchor { margin-left: 8px; color: var(--nv-green); opacity: 0;
  text-decoration: none; font-weight: 400; transition: opacity 0.12s; }
main h2:hover .anchor, main h3:hover .anchor { opacity: 0.6; }
.anchor:hover { opacity: 1 !important; text-decoration: none; }

/* ---------- breadcrumbs + edit link ---------- */
.crumb-bar { display: flex; align-items: center; justify-content: space-between;
  gap: 12px; margin: 0 0 22px; flex-wrap: wrap; }
.crumbs { font-size: 13px; color: var(--text-muted); display: flex;
  align-items: center; gap: 6px; flex-wrap: wrap; }
.crumbs a { color: var(--text-muted); }
.crumbs a:hover { color: var(--nv-green-dark); }
.crumbs .sep { opacity: 0.5; }
.crumbs .cur { color: var(--text); font-weight: 600; }
.edit-link { font-size: 12.5px; color: var(--text-muted);
  border: 1px solid var(--border); border-radius: 7px; padding: 4px 10px; white-space: nowrap; }
.edit-link:hover { border-color: var(--nv-green); color: var(--nv-green-dark); text-decoration: none; }

/* ---------- homepage: stats + features ---------- */
.stat-row { display: grid; grid-template-columns: repeat(4, 1fr); gap: 14px; margin: 28px 0; }
.stat { border: 1px solid var(--border); border-radius: 12px; padding: 18px 16px;
  text-align: center; background: var(--bg-sidebar); }
.stat-num { display: block; font-size: 1.7rem; font-weight: 800; color: var(--nv-green-dark); line-height: 1.1; }
[data-theme="dark"] .stat-num { color: var(--nv-green); }
.stat-lbl { display: block; font-size: 12px; color: var(--text-muted); margin-top: 4px; }
.feature-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 16px; margin: 22px 0; }
.feature { border: 1px solid var(--border); border-radius: 12px; padding: 20px; }
.feature-ico { font-size: 1.6rem; margin-bottom: 8px; line-height: 1; }
.feature h3 { margin: 0 0 6px; font-size: 1.05rem; }
.feature p { margin: 0; font-size: 0.9rem; color: var(--text-muted); }
@media (max-width: 640px) { .stat-row { grid-template-columns: repeat(2, 1fr); } }

/* ---------- Content ---------- */
main h1 { font-size: 2.1rem; margin: 0 0 0.6em; line-height: 1.2; }
main h2 { font-size: 1.5rem; margin: 1.8em 0 0.6em;
  padding-bottom: 0.2em; border-bottom: 1px solid var(--border); }
main h3 { font-size: 1.2rem; margin: 1.4em 0 0.5em; }
main p { margin: 0.8em 0; }
main ul, main ol { padding-left: 1.4em; }
main li { margin: 0.3em 0; }

.lead { font-size: 1.15rem; color: var(--text-muted); }

code {
  font-family: "SF Mono", "JetBrains Mono", Menlo, Consolas, monospace;
  font-size: 0.88em;
  background: var(--bg-code);
  padding: 0.15em 0.4em; border-radius: 4px;
}
pre {
  background: var(--bg-code);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 16px 18px;
  overflow-x: auto;
  font-size: 13.5px; line-height: 1.55;
  position: relative;
}
pre code { background: none; padding: 0; font-size: inherit; }
pre[data-lang]::before {
  content: attr(data-lang);
  position: absolute; top: 0; right: 0;
  font-size: 10px; font-weight: 700; letter-spacing: 0.06em;
  text-transform: uppercase; color: var(--text-muted);
  background: var(--border); padding: 2px 8px;
  border-radius: 0 9px 0 8px; opacity: 0.7;
}
pre:hover[data-lang]::before { opacity: 0; }   /* yield to copy button on hover */
pre[data-status="dev"]::after {                /* "开发中 / In development" badge on not-yet-runnable code */
  content: attr(data-status-label);
  position: absolute; top: 0; left: 0;
  font-size: 10px; font-weight: 700; letter-spacing: 0.04em;
  color: #fff; background: #d97706;
  padding: 2px 9px; border-radius: 9px 0 8px 0;
  opacity: 0.92;
}
pre[data-status="dev"] { border-color: #d97706; }
.copy-btn {
  position: absolute; top: 8px; right: 8px;
  background: var(--bg); border: 1px solid var(--border);
  border-radius: 6px; font-size: 11px; padding: 3px 8px;
  cursor: pointer; color: var(--text-muted); opacity: 0;
  transition: opacity 0.15s;
}
pre:hover .copy-btn { opacity: 1; }

/* syntax tokens */
.tok-kw { color: #a626a4; }
.tok-fn { color: #4078f2; }
.tok-str { color: #50a14f; }
.tok-num { color: #986801; }
.tok-com { color: #9aa39a; font-style: italic; }
[data-theme="dark"] .tok-kw { color: #c678dd; }
[data-theme="dark"] .tok-fn { color: #61afef; }
[data-theme="dark"] .tok-str { color: #98c379; }
[data-theme="dark"] .tok-num { color: #d19a66; }

/* admonitions */
.admon { border-radius: 8px; padding: 12px 16px; margin: 1.2em 0;
  border-left: 4px solid var(--nv-green); background: rgba(236,72,153,0.08); }
.admon.note { border-color: #4078f2; background: rgba(64,120,242,0.08); }
.admon.warning { border-color: #e0a800; background: rgba(224,168,0,0.10); }
/* three-tier capability-status banners */
.admon.status-runnable { border-color: #2ea043; background: rgba(46,160,67,0.09); }
.admon.status-design   { border-color: #4078f2; background: rgba(64,120,242,0.07); }
.admon.status-planned  { border-color: #e0a800; background: rgba(224,168,0,0.10); }
.admon.status-runnable .admon-title { color: #2ea043; }
.admon.status-design .admon-title   { color: #4078f2; }
.admon.status-planned .admon-title  { color: #b88600; }
.admon .admon-title { font-weight: 700; margin-bottom: 4px; font-size: 0.9em;
  text-transform: uppercase; letter-spacing: 0.04em; }

/* what's-new timeline */
.news-timeline { position: relative; margin: 1.2em 0 1.6em; padding-left: 26px; }
.news-timeline::before { content: ""; position: absolute; left: 7px; top: 6px; bottom: 6px;
  width: 2px; background: linear-gradient(var(--nv-green), #f9a8d4); }
.news-item { position: relative; margin: 0 0 16px; }
.news-item::before { content: ""; position: absolute; left: -26px; top: 5px; width: 12px; height: 12px;
  border-radius: 50%; background: var(--nv-green); border: 2px solid var(--bg); box-shadow: 0 0 0 2px var(--nv-green); }
.news-date { display: inline-block; font-size: 0.78rem; font-weight: 700; color: var(--nv-green-dark);
  background: rgba(236,72,153,0.10); border-radius: 20px; padding: 2px 12px; margin-bottom: 6px;
  letter-spacing: 0.02em; }
[data-theme="dark"] .news-date { color: #f9a8d4; }
.news-card { border: 1px solid var(--border); border-radius: 10px; padding: 12px 16px;
  background: var(--bg-sidebar); }
.news-card h3 { margin: 0 0 6px; font-size: 1.05rem; line-height: 1.35; }
.news-card p { margin: 0; color: var(--text-muted); font-size: 0.95rem; }
.news-year { font-size: 1.1rem; color: var(--nv-green-dark); margin: 1.2em 0 0.4em;
  border-bottom: 2px solid rgba(236,72,153,0.25); padding-bottom: 3px; }
[data-theme="dark"] .news-year { color: #f9a8d4; }
.news-src { font-size: 0.9rem; color: var(--text-muted); margin: 0.2em 0 0.9em; }

/* live news feed */
.feed-list { display: flex; flex-direction: column; gap: 8px; margin: 0 0 1.4em; }
.feed-item { display: flex; gap: 14px; align-items: flex-start; text-decoration: none;
  border: 1px solid var(--border); border-radius: 10px; padding: 11px 15px;
  background: var(--bg); transition: border-color .15s, transform .15s, box-shadow .15s; }
.feed-item:hover { border-color: var(--nv-green); transform: translateY(-1px);
  box-shadow: 0 3px 14px rgba(236,72,153,0.12); }
.feed-date { flex: 0 0 84px; font-size: 0.76rem; font-weight: 700; color: var(--nv-green-dark);
  padding-top: 2px; white-space: nowrap; }
[data-theme="dark"] .feed-date { color: #f9a8d4; }
.feed-main { display: flex; flex-direction: column; gap: 2px; min-width: 0; }
.feed-title { font-weight: 650; color: var(--text); font-size: 0.98rem; line-height: 1.35; }
.feed-item:hover .feed-title { color: var(--nv-green-dark); }
[data-theme="dark"] .feed-item:hover .feed-title { color: #f9a8d4; }
.feed-desc { color: var(--text-muted); font-size: 0.86rem; line-height: 1.4;
  display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
@media (max-width: 560px) { .feed-item { flex-direction: column; gap: 3px; } .feed-date { flex-basis: auto; } }

/* hero / cards */
.hero {
  background: linear-gradient(135deg, #2a1620 0%, #6b1f3a 60%, var(--nv-green-dark) 130%);
  color: #fff; border-radius: 16px; padding: 44px 40px; margin-bottom: 36px;
}
.hero { display: flex; align-items: center; gap: 28px; }
.hero-text { flex: 1 1 58%; min-width: 0; }
.hero-art { flex: 1 1 40%; max-width: 380px; }
.hero-circuit { width: 100%; height: auto; display: block; }
@media (max-width: 760px) { .hero { flex-direction: column; } .hero-art { width: 100%; max-width: 420px; } }
.hero h1 { color: #fff; margin: 0 0 10px; font-size: 2.4rem; }
.hero p { color: #fbd4e6; font-size: 1.15rem; margin: 0 0 20px; max-width: 620px; }
.hero .btns { display: flex; gap: 12px; flex-wrap: wrap; }
.btn {
  display: inline-block; padding: 10px 20px; border-radius: 8px;
  font-weight: 600; font-size: 14px;
}
.btn-primary { background: var(--nv-green); color: #fff; }
.btn-primary:hover { background: #f472b6; text-decoration: none; }
.btn-ghost { background: rgba(255,255,255,0.12); color: #fff; border: 1px solid rgba(255,255,255,0.3); }
.btn-ghost:hover { background: rgba(255,255,255,0.2); text-decoration: none; }

.card-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(230px, 1fr)); gap: 16px; margin: 24px 0; }
.card {
  border: 1px solid var(--border); border-radius: 12px; padding: 20px;
  background: var(--bg); transition: border-color 0.15s, transform 0.15s;
}
.card:hover { border-color: var(--nv-green); transform: translateY(-2px); text-decoration: none; }
.card h3 { margin: 0 0 6px; font-size: 1.05rem; color: var(--text); }
.card p { margin: 0; font-size: 0.9rem; color: var(--text-muted); }

table { border-collapse: collapse; width: 100%; margin: 1.2em 0; font-size: 14px; }
th, td { border: 1px solid var(--border); padding: 8px 12px; text-align: left; }
th { background: var(--bg-sidebar); font-weight: 600; }

.page-nav { display: flex; justify-content: space-between; margin-top: 48px;
  padding-top: 20px; border-top: 1px solid var(--border); gap: 16px; }
.page-nav a { flex: 1; padding: 14px 18px; border: 1px solid var(--border);
  border-radius: 10px; font-size: 14px; }
.page-nav a:hover { border-color: var(--nv-green); text-decoration: none; }
.page-nav a.next { text-align: right; }
.page-nav .lbl { display: block; font-size: 11px; color: var(--text-muted); text-transform: uppercase; }
.page-nav .ttl { font-weight: 600; color: var(--nv-green-dark); }

footer.site { border-top: 1px solid var(--border); padding: 24px 48px;
  color: var(--text-muted); font-size: 13px; max-width: 1100px; }
footer.site .foot-meta { color: var(--text); font-size: 13px; margin-bottom: 8px; }
footer.site .foot-dot { margin: 0 8px; opacity: .5; }
footer.site .foot-sources { font-size: 12.5px; margin-bottom: 10px; opacity: .9; }
footer.site .foot-sources a { margin: 0 4px; white-space: nowrap; }
footer.site .foot-sources a:first-of-type { margin-left: 6px; }
footer.site .foot-disclaimer { display: block; margin-top: 8px; font-size: 12px; opacity: .75; }
[data-lang="en"] footer.site .foot-disclaimer.zh,
[data-lang="zh"] footer.site .foot-disclaimer.en { display: none; }

.badge { display: inline-block; font-size: 11px; font-weight: 600;
  padding: 2px 8px; border-radius: 4px; background: var(--bg-sidebar);
  border: 1px solid var(--border); color: var(--text-muted); margin-left: 6px; }

/* ---------- Responsive ---------- */
@media (max-width: 1100px) { aside.toc { display: none; } }
@media (max-width: 820px) {
  .menu-toggle { display: block; }
  nav.sidebar { position: fixed; left: 0; top: var(--header-h); z-index: 90;
    transform: translateX(-100%); transition: transform 0.2s; }
  nav.sidebar.open { transform: translateX(0); }
  main { padding: 24px 20px 60px; }
  .topbar .search { max-width: 200px; }
}

/* ---------- print ---------- */
@media print {
  header.topbar, nav.sidebar, aside.toc, .page-nav, .edit-link,
  .copy-btn, #search-results { display: none !important; }
  .layout { display: block; padding-top: 0; }
  main { max-width: 100%; padding: 0; }
  body { font-size: 12pt; color: #000; background: #fff; }
  a { color: #000; text-decoration: underline; }
  pre { white-space: pre-wrap; word-break: break-word; border: 1px solid #ccc; }
  .hero { background: #f0f0f0 !important; color: #000; }
  .hero h1, .hero p { color: #000; }
}

/* ---------- back-to-top + toast ---------- */
.to-top {
  position: fixed; bottom: 24px; right: 24px; z-index: 90;
  width: 42px; height: 42px; border-radius: 50%; border: none;
  background: var(--nv-green); color: #fff; font-size: 20px; cursor: pointer;
  box-shadow: 0 6px 18px rgba(0,0,0,0.22);
  opacity: 0; pointer-events: none; transform: translateY(8px);
  transition: opacity 0.2s, transform 0.2s, background 0.15s;
}
.to-top:hover { background: var(--nv-green-dark); }
.to-top.show { opacity: 1; pointer-events: auto; transform: none; }
.toast {
  position: fixed; bottom: 28px; left: 50%; z-index: 300;
  transform: translateX(-50%) translateY(12px);
  background: #1a1a1a; color: #fff; padding: 9px 18px; border-radius: 9px;
  font-size: 13px; box-shadow: 0 8px 24px rgba(0,0,0,0.3);
  opacity: 0; pointer-events: none; transition: opacity 0.2s, transform 0.2s;
}
.toast.show { opacity: 1; transform: translateX(-50%); }
@media print { .to-top, .toast { display: none !important; } }

/* ---------- mobile sidebar backdrop ---------- */
.sidebar-backdrop { display: none; }
@media (max-width: 820px) {
  body.nav-open .sidebar-backdrop {
    display: block; position: fixed; inset: var(--header-h) 0 0 0;
    background: rgba(0,0,0,0.4); z-index: 80;
  }
}

/* ---------- 404 ---------- */
.notfound { text-align: center; padding: 60px 20px; }
.nf-code { font-size: 6rem; font-weight: 800; line-height: 1;
  background: linear-gradient(135deg, var(--nv-green), #be185d);
  -webkit-background-clip: text; background-clip: text; color: transparent; }
.notfound h1 { border: none; margin-top: 10px; }
.notfound .lead { max-width: 460px; margin: 12px auto 24px; }
.notfound .btns { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }

/* ---------- interactive backend selector ---------- */
.backend-selector { margin: 22px 0; }
.bsel-filters { display: flex; flex-direction: column; gap: 12px; margin-bottom: 18px; }
.bsel-group { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
.bsel-label { font-size: 12px; font-weight: 700; text-transform: uppercase;
  letter-spacing: 0.04em; color: var(--text-muted); min-width: 110px; }
.bsel-group button {
  background: var(--bg); border: 1px solid var(--border); border-radius: 20px;
  padding: 5px 14px; font-size: 13px; cursor: pointer; color: var(--text);
  transition: all 0.12s;
}
.bsel-group button:hover { border-color: var(--nv-green); }
.bsel-group button.active { background: var(--nv-green); border-color: var(--nv-green); color: #fff; }
.bsel-count { font-size: 13px; color: var(--text-muted); margin-bottom: 12px; }
.bsel-results { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 14px; }
.bsel-card { display: block; border: 1px solid var(--border); border-radius: 12px;
  padding: 16px; background: var(--bg); transition: border-color 0.15s, transform 0.15s; }
.bsel-card:hover { border-color: var(--nv-green); transform: translateY(-2px); text-decoration: none; }
.bsel-name { font-weight: 700; font-size: 15px; color: var(--text); margin-bottom: 8px; }
.bsel-tags { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; margin-bottom: 10px; }
.bsel-badge { font-size: 11px; font-weight: 600; color: #fff; background: var(--nv-green);
  padding: 2px 9px; border-radius: 20px; }
.bsel-q { font-size: 12px; color: var(--text-muted); }
.bsel-target { display: block; font-size: 11.5px; background: var(--bg-code);
  border: 1px solid var(--border); border-radius: 6px; padding: 5px 8px; color: var(--nv-green-dark);
  word-break: break-all; }
[data-theme="dark"] .bsel-target { color: var(--nv-green); }
.bsel-empty { grid-column: 1 / -1; padding: 24px; text-align: center; color: var(--text-muted);
  border: 1px dashed var(--border); border-radius: 12px; }

/* ---------- in-browser playground ---------- */
.qplay { border: 1px solid var(--border); border-radius: 14px; padding: 18px; margin: 22px 0;
  background: var(--bg-sidebar); }
.qp-row { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; margin-bottom: 12px; }
.qp-lab { font-size: 12px; font-weight: 700; text-transform: uppercase; letter-spacing: 0.04em;
  color: var(--text-muted); }
.qplay select { padding: 4px 8px; border: 1px solid var(--border); border-radius: 7px;
  background: var(--bg); color: var(--text); font-size: 13px; }
.qp-targets button, .qp-controls button {
  width: 34px; height: 30px; margin-right: 4px; border: 1px solid var(--border);
  border-radius: 7px; background: var(--bg); color: var(--text); cursor: pointer; font-size: 12px;
}
.qp-targets button.active, .qp-controls button.active {
  background: var(--nv-green); border-color: var(--nv-green); color: #fff; font-weight: 700; }
.qp-palette { display: flex; gap: 6px; flex-wrap: wrap; margin-bottom: 14px; }
.qp-palette button { width: 40px; height: 38px; border: 1px solid var(--border); border-radius: 8px;
  background: var(--bg); color: var(--text); cursor: pointer; font-weight: 700; font-size: 14px; }
.qp-palette button:hover { border-color: var(--nv-green); color: var(--nv-green-dark); }
.qp-palette button.qp-cx { width: auto; padding: 0 14px; }
.qp-circuit-wrap { display: block; margin-bottom: 14px; }
.qp-circuit-wrap > .qp-lab { display: block; margin-bottom: 6px; }
.qp-circuit { min-height: 40px; overflow-x: auto; padding: 6px 4px;
  border: 1px solid var(--border); border-radius: 10px; background: var(--bg); }
.qp-circuit-svg { display: block; }
.qp-empty { color: var(--text-muted); font-size: 13px; padding: 8px; }
.qp-run { cursor: pointer; }
.qp-undo, .qp-clear { background: var(--bg); border: 1px solid var(--border); border-radius: 8px;
  padding: 9px 16px; cursor: pointer; color: var(--text); font-size: 13px; }
.qp-undo:hover, .qp-clear:hover { border-color: var(--nv-green); }
.qp-results { margin-top: 16px; }
.qp-hist-title { font-size: 12px; font-weight: 700; text-transform: uppercase; color: var(--text-muted);
  margin-bottom: 10px; letter-spacing: 0.04em; }
.qp-bar { display: flex; align-items: center; gap: 10px; margin: 5px 0; }
.qp-bits { font-family: monospace; font-size: 13px; width: 70px; flex-shrink: 0; }
.qp-track { flex: 1; height: 18px; background: var(--border); border-radius: 5px; overflow: hidden; }
.qp-fill { display: block; height: 100%; background: linear-gradient(90deg, var(--nv-green), #f472b6); }
.qp-pct { font-size: 12px; color: var(--text-muted); width: 110px; flex-shrink: 0; text-align: right; }
.qp-amps { margin-top: 14px; font-family: monospace; font-size: 12px; color: var(--text-muted);
  line-height: 1.9; word-break: break-word; }

/* ---------- homepage tool strip ---------- */
.tool-strip { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; margin: 24px 0; }
.tool-card { display: flex; align-items: center; gap: 14px; padding: 18px 20px;
  border: 1px solid var(--border); border-radius: 14px;
  background: linear-gradient(135deg, rgba(236,72,153,0.07), rgba(236,72,153,0.02));
  transition: border-color 0.15s, transform 0.15s; }
.tool-card:hover { border-color: var(--nv-green); transform: translateY(-2px); text-decoration: none; }
.tool-ico { font-size: 1.6rem; width: 46px; height: 46px; flex-shrink: 0; border-radius: 11px;
  background: var(--nv-green); color: #fff; display: grid; place-items: center; }
.tool-card strong { display: block; color: var(--text); font-size: 1.05rem; margin-bottom: 3px; }
.tool-card small { display: block; color: var(--text-muted); font-size: 0.85rem; line-height: 1.4; }
@media (max-width: 640px) { .tool-strip { grid-template-columns: 1fr; } }

/* ---------- playground: rotations + Bloch sphere ---------- */
.qp-anglerow { gap: 8px; }
.qp-angle { flex: 0 0 160px; accent-color: var(--nv-green); cursor: pointer; }
.qp-angleval { font-family: monospace; font-size: 13px; color: var(--text-muted); width: 44px; }
.qp-anglerow button[data-gate] { width: 44px; height: 34px; border: 1px solid var(--border);
  border-radius: 8px; background: var(--bg); color: var(--text); cursor: pointer; font-weight: 700; font-size: 13px; }
.qp-anglerow button[data-gate]:hover { border-color: var(--nv-green); color: var(--nv-green-dark); }
.qp-bloch { margin-top: 18px; }
.qp-bloch-title { font-size: 12px; font-weight: 700; text-transform: uppercase; color: var(--text-muted);
  margin-bottom: 8px; letter-spacing: 0.04em; }
.qp-bloch-row { display: flex; flex-wrap: wrap; gap: 6px; }
.qp-bloch-cell { text-align: center; }
.qp-bloch-svg { width: 108px; height: auto; display: block; }
.qp-bloch-lab { font-family: monospace; font-size: 11px; color: var(--text-muted); margin-top: 2px; }
.qp-amp-table { width: auto; font-size: 12.5px; margin-top: 8px; }
.qp-amp-table th, .qp-amp-table td { padding: 4px 14px 4px 0; text-align: left; font-family: monospace; }
.qp-amp-table th { color: var(--text-muted); font-weight: 600; border-bottom: 1px solid var(--border); }
.qp-bloch-coords { font-family: monospace; font-size: 12px; color: var(--text-muted); margin-top: 4px; }
.qp-bloch-note { font-size: 12.5px; color: var(--text-muted); padding: 12px 14px;
  border: 1px dashed var(--border); border-radius: 10px; }

/* ---------- references / citations ---------- */
.ref-list { list-style: none; margin: 1em 0; padding: 0; counter-reset: ref; }
.ref-list li { position: relative; padding: 8px 0 8px 32px; font-size: 14px; line-height: 1.55;
  border-bottom: 1px solid var(--border); color: var(--text); }
.ref-list li:last-child { border-bottom: none; }
.ref-list li::before { counter-increment: ref; content: "[" counter(ref) "]";
  position: absolute; left: 0; top: 8px; color: var(--nv-green-dark); font-weight: 700; font-size: 12.5px; }
[data-theme="dark"] .ref-list li::before { color: var(--nv-green); }
.ref-list em { color: var(--text-muted); }
.ref-list a { word-break: break-word; }

/* ---------- playground: Q-sphere + export ---------- */
.qp-viz { display: flex; flex-wrap: wrap; gap: 24px; align-items: flex-start; }
.qp-viz-col { flex: 0 0 auto; }
.qp-qsphere-svg { width: 220px; height: auto; display: block; }
.qp-export { margin-top: 20px; }
.qp-exp-tabs { display: flex; gap: 6px; flex-wrap: wrap; margin-bottom: 8px; align-items: center; }
.qp-exp-btn { background: var(--bg); border: 1px solid var(--border); border-radius: 7px;
  padding: 4px 12px; font-size: 12.5px; cursor: pointer; color: var(--text); }
.qp-exp-btn:hover { border-color: var(--nv-green); }
.qp-exp-btn.active { background: var(--nv-green); border-color: var(--nv-green); color: #fff; font-weight: 600; }
.qp-exp-copy { margin-left: auto; background: var(--bg); border: 1px solid var(--border);
  border-radius: 6px; font-size: 11px; padding: 3px 10px; cursor: pointer; color: var(--text-muted); }
.qp-exp-copy:hover { border-color: var(--nv-green); }
.qp-exp-code { margin: 0; }
.qp-exp-code code { white-space: pre; }

/* ---------- playground: phase legend ---------- */
.qp-phase-legend { display: flex; align-items: center; gap: 12px; margin-top: 8px; }
.qp-pl-box { position: relative; width: 78px; height: 78px; flex-shrink: 0; }
.qp-pl-ring { position: absolute; inset: 8px; border-radius: 50%;
  background: conic-gradient(from 90deg,
    hsl(90,70%,55%), hsl(180,70%,55%), hsl(270,70%,55%), hsl(360,70%,55%), hsl(90,70%,55%));
  -webkit-mask: radial-gradient(circle, transparent 38%, #000 40%);
          mask: radial-gradient(circle, transparent 38%, #000 40%); }
.qp-pl-lab { position: absolute; font-size: 10px; color: var(--text-muted); }
.qp-pl-t { top: -3px; left: 50%; transform: translateX(-50%); }
.qp-pl-r { right: -8px; top: 50%; transform: translateY(-50%); }
.qp-pl-b { bottom: -3px; left: 50%; transform: translateX(-50%); }
.qp-pl-l { left: -10px; top: 50%; transform: translateY(-50%); }
.qp-pl-cap { font-size: 12px; color: var(--text-muted); max-width: 140px; line-height: 1.4; }

/* ---------- playground: clickable gates ---------- */
.qp-gate { cursor: pointer; }
.qp-gate:hover .qp-gate-hit { fill: rgba(236,72,153,0.10); }
.qp-gate:hover rect:not(.qp-gate-hit) { stroke-width: 2.5; }

.qp-hint { font-size: 11.5px; color: var(--text-muted); margin-top: 6px; }

/* ---------- playground: drag-to-place ---------- */
.qp-palette button[data-gate], .qp-anglerow button[data-gate] { cursor: grab; }
.qp-circuit.qp-drop { border-color: var(--nv-green); border-style: dashed;
  background: rgba(236,72,153,0.05); }

/* ---------- homepage demo video ---------- */
.demo-wrap { position: relative; margin: 26px 0; border-radius: 14px; overflow: hidden;
  border: 1px solid var(--border); background: #000; line-height: 0; }
.demo-vid { width: 100%; height: auto; display: block; cursor: pointer; }
.demo-play { position: absolute; inset: 0; margin: auto; width: max-content; height: max-content;
  display: flex; align-items: center; gap: 10px; padding: 14px 26px; border: none; cursor: pointer;
  background: rgba(236,72,153,0.92); color: #fff; font-size: 16px; font-weight: 700; border-radius: 12px;
  box-shadow: 0 8px 28px rgba(0,0,0,0.4); transition: transform 0.15s, background 0.15s; }
.demo-play:hover { transform: scale(1.04); background: var(--nv-green); }
.demo-tri { font-size: 18px; }
.demo-wrap.playing .demo-play { display: none; }
.demo-transcript { margin: -14px 0 26px; border: 1px solid var(--border); border-radius: 12px;
  background: var(--bg-sidebar); overflow: hidden; }
.demo-transcript > summary { cursor: pointer; padding: 11px 16px; font-size: 13px; font-weight: 600;
  color: var(--text-muted); list-style: none; user-select: none; }
.demo-transcript > summary::-webkit-details-marker { display: none; }
.demo-transcript > summary::before { content: "\25B8"; display: inline-block; margin-right: 8px;
  transition: transform 0.15s; color: #ec4899; }
.demo-transcript[open] > summary::before { transform: rotate(90deg); }
.ts-list { margin: 0; padding: 0 0 6px; list-style: none; }
.ts-row { display: flex; gap: 12px; align-items: baseline; padding: 7px 16px; cursor: pointer;
  font-size: 14px; line-height: 1.5; border-left: 3px solid transparent; transition: background 0.1s; }
.ts-row:hover { background: rgba(236,72,153,0.07); }
.ts-row.active { background: rgba(236,72,153,0.12); border-left-color: #ec4899; }
.ts-time { flex: none; width: 34px; font-variant-numeric: tabular-nums; font-size: 12px;
  font-weight: 600; color: #ec4899; padding-top: 1px; }
.ts-text { color: var(--text); }

/* Back-to-hub link in the topbar */
.hub-link{font-size:13px;font-weight:600;color:var(--text-muted);text-decoration:none;
  padding:5px 11px;border:1px solid var(--border);border-radius:999px;white-space:nowrap;
  transition:border-color .15s,color .15s}
.hub-link::before{content:"↩ ";opacity:.8}
.hub-link:hover{border-color:#ec4899;color:#ec4899}
.ask-link::before{content:"" !important}
.ask-link{border-color:transparent !important;color:#fff !important;background:linear-gradient(90deg,#ec4899,#8b5cf6)}
.ask-link:hover{color:#fff !important;filter:brightness(1.07)}
.scan-link::before{content:"" !important}
.scan-link{border-color:#8b5cf6 !important;color:#8b5cf6 !important}
.scan-link:hover{background:#8b5cf6;color:#fff !important}
@media (max-width:760px){.hub-link{display:none}}

/* Corrections / feedback form (footer link → corrections.html) */
.correction-form { display: flex; flex-direction: column; gap: 14px; max-width: 640px;
  margin: 18px 0 28px; }
.correction-form label { display: flex; flex-direction: column; gap: 6px;
  font-size: 14px; font-weight: 600; color: var(--text); }
.correction-form input, .correction-form select, .correction-form textarea {
  font: inherit; font-weight: 400; padding: 9px 11px; border: 1px solid var(--border);
  border-radius: 8px; background: var(--bg); color: var(--text); width: 100%; }
.correction-form textarea { resize: vertical; }
.correction-form input:focus, .correction-form select:focus, .correction-form textarea:focus {
  outline: none; border-color: #ec4899; box-shadow: 0 0 0 3px rgba(236,72,153,0.15); }
.correction-form .btn { align-self: flex-start; cursor: pointer; }
.cf-result { font-size: 14px; color: var(--text-muted); margin: 4px 0 0; min-height: 1.2em; }
.cf-result code { color: #ec4899; }