:root {
  --bg: #0f1117;
  --panel: #181b24;
  --panel-2: #1f2330;
  --border: #2a2f3d;
  --text: #e6e8ee;
  --muted: #9aa3b2;
  --accent: #7c8cff;
  --accent-2: #5be0c0;
  --good: #5be08a;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
  --tok0: #3b4cca33; --tok1: #2f9e8f33; --tok2: #c45c9933; --tok3: #c98a2e33;
  --tok4: #8b5cf633; --tok5: #2d8fce33; --tok6: #cf5b5b33; --tok7: #6ab04c33;
  --tok0b: #8b9bff; --tok1b: #4fd6c1; --tok2b: #ff8ac4; --tok3b: #ffc06b;
  --tok4b: #b89bff; --tok5b: #6fc4ff; --tok6b: #ff9090; --tok7b: #9be07a;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: radial-gradient(1200px 600px at 50% -10%, #1a1f2e 0%, var(--bg) 55%);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  line-height: 1.5;
  padding: 0 20px 60px;
}

/* =========================================================== HEADER + TABS */
header { max-width: 980px; margin: 0 auto; padding: 34px 0 0; }
.header-inner { display: flex; justify-content: space-between; align-items: flex-start; padding-bottom: 12px; }
h1 { font-size: 30px; margin: 0 0 6px; letter-spacing: -0.5px; }
.sub { color: var(--muted); max-width: 760px; margin: 0; font-size: 14.5px; }
.sub b { color: var(--text); font-weight: 600; }

.badge {
  display: inline-block; margin-left: 6px; padding: 1px 8px; border-radius: 99px;
  background: var(--panel-2); border: 1px solid var(--border); color: var(--accent-2);
  font: 600 11px/1.6 var(--mono); vertical-align: middle; flex-shrink: 0; margin-top: 6px;
}

.page-tabs { display: flex; border-bottom: 1px solid var(--border); margin: 0; }
.page-tab {
  background: none; border: none; color: var(--muted); padding: 11px 22px 10px;
  font-size: 14px; font-weight: 600; cursor: pointer; border-bottom: 2px solid transparent;
  margin-bottom: -1px; transition: .12s;
}
.page-tab:hover { color: var(--text); }
.page-tab.active { color: var(--accent); border-bottom-color: var(--accent); }

.tab-panel { display: none; }
.tab-panel.active { display: block; }

/* =========================================================== PLAYGROUND */
.controls {
  max-width: 980px; margin: 20px auto 0; display: flex; gap: 26px; flex-wrap: wrap;
  align-items: flex-start;
}
.control label {
  display: block; font-size: 11px; text-transform: uppercase; letter-spacing: 0.8px;
  color: var(--muted); margin-bottom: 7px; font-weight: 600;
}
.hint { color: var(--muted); font-size: 12.5px; margin-top: 6px; max-width: 520px; }

select#corpus {
  background: var(--panel-2); color: var(--text); border: 1px solid var(--border);
  border-radius: 9px; padding: 9px 12px; font-size: 14px; min-width: 220px; cursor: pointer;
}

.segmented { display: inline-flex; background: var(--panel-2); border: 1px solid var(--border);
  border-radius: 10px; padding: 3px; gap: 3px; }
.segmented button {
  border: 0; background: transparent; color: var(--muted); padding: 7px 14px;
  border-radius: 7px; cursor: pointer; font-size: 13.5px; font-weight: 600; transition: .12s;
}
.segmented button:hover { color: var(--text); }
.segmented button.active { background: var(--accent); color: #0b0d14; }

main { max-width: 980px; margin: 22px auto 0; display: flex; flex-direction: column; gap: 16px; }

.panel {
  background: var(--panel); border: 1px solid var(--border); border-radius: 14px;
  padding: 16px 18px;
}
.panel-label { font-size: 12px; text-transform: uppercase; letter-spacing: 0.7px;
  color: var(--muted); font-weight: 700; }
.panel-head { display: flex; justify-content: space-between; align-items: center; margin-bottom: 12px; }
.panel-note { color: var(--muted); font-size: 12px; }

textarea#text {
  width: 100%; margin-top: 10px; background: var(--panel-2); color: var(--text);
  border: 1px solid var(--border); border-radius: 10px; padding: 12px 14px;
  font-size: 15px; resize: vertical; font-family: inherit; line-height: 1.5;
}
textarea#text:focus, select:focus { outline: 2px solid var(--accent); outline-offset: 1px; }

.length-badge {
  font: 700 13px/1 var(--mono); color: var(--accent-2); background: var(--panel-2);
  border: 1px solid var(--border); padding: 6px 11px; border-radius: 99px;
  transition: transform .12s ease;
}
.length-badge.pulse { transform: scale(1.14); }

/* token chips */
.tokens { display: flex; flex-wrap: wrap; gap: 4px; min-height: 30px; }
.tokens.big { gap: 6px; }
.tok {
  font-family: var(--mono); font-size: 14px; padding: 4px 6px; border-radius: 6px;
  white-space: pre; border: 1px solid #ffffff14; cursor: default; position: relative;
}
.tokens.big .tok { font-size: 17px; padding: 7px 10px; }
.tok.c0 { background: var(--tok0); color: var(--tok0b); }
.tok.c1 { background: var(--tok1); color: var(--tok1b); }
.tok.c2 { background: var(--tok2); color: var(--tok2b); }
.tok.c3 { background: var(--tok3); color: var(--tok3b); }
.tok.c4 { background: var(--tok4); color: var(--tok4b); }
.tok.c5 { background: var(--tok5); color: var(--tok5b); }
.tok.c6 { background: var(--tok6); color: var(--tok6b); }
.tok.c7 { background: var(--tok7); color: var(--tok7b); }
.tok .tip {
  display: none; position: absolute; bottom: calc(100% + 6px); left: 50%;
  transform: translateX(-50%); background: #000; color: #fff; padding: 3px 7px;
  border-radius: 6px; font-size: 11px; white-space: nowrap; z-index: 5; border: 1px solid var(--border);
}
.tok:hover { filter: brightness(1.35); border-color: #ffffff44; }
.tok:hover .tip { display: block; }
.placeholder { color: var(--muted); font-style: italic; }

.ids-wrap { margin-top: 12px; }
.link { background: none; border: 0; color: var(--accent); cursor: pointer; font-size: 12.5px; padding: 0; }
.ids { margin-top: 8px; font-family: var(--mono); font-size: 12.5px; color: var(--muted);
  word-break: break-all; background: var(--panel-2); border-radius: 8px; padding: 9px 11px; }
.hidden { display: none; }

/* prediction bars */
.bars { display: flex; flex-direction: column; gap: 5px; }
.bar-row { display: grid; grid-template-columns: 96px 1fr 56px; align-items: center; gap: 10px; }
.bar-tok { font-family: var(--mono); font-size: 13px; text-align: right; color: var(--text);
  overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.bar-track { background: var(--panel-2); border-radius: 6px; height: 22px; overflow: hidden; border: 1px solid var(--border); }
.bar-fill {
  height: 100%; width: 0; border-radius: 6px 0 0 6px;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  transition: width .25s ease;
}
.bar-pct { font: 600 12px/1 var(--mono); color: var(--muted); }

/* comparison cards */
.compare { display: flex; gap: 10px; flex-wrap: wrap; margin: 10px 0 4px; }
.cmp-card {
  flex: 1 1 150px; background: var(--panel-2); border: 1px solid var(--border);
  border-radius: 11px; padding: 11px 13px; transition: .15s;
}
.cmp-card.active { border-color: var(--accent); box-shadow: 0 0 0 1px var(--accent); }
.cmp-name { font-weight: 700; font-size: 14px; margin-bottom: 7px; display: flex;
  justify-content: space-between; align-items: baseline; }
.cmp-len { font: 800 19px/1 var(--mono); color: var(--accent-2); }
.cmp-row { display: flex; justify-content: space-between; font-size: 12px; color: var(--muted); margin-top: 3px; }
.cmp-row b { color: var(--text); font-family: var(--mono); font-weight: 600; }
.cmp-best b { color: var(--good); }

/* merge visualizer */
.merge-controls { display: flex; align-items: center; gap: 12px; margin-bottom: 14px; flex-wrap: wrap; }
.merge-controls label { font-size: 11px; text-transform: uppercase; color: var(--muted); letter-spacing: .8px; font-weight: 600; }
#merge-word { background: var(--panel-2); border: 1px solid var(--border); color: var(--text);
  border-radius: 8px; padding: 7px 10px; font-family: var(--mono); width: 150px; }
#merge-slider { flex: 1; min-width: 180px; accent-color: var(--accent); }
.mono { font-family: var(--mono); font-size: 12.5px; color: var(--muted); white-space: nowrap; }
.merge-applied { margin-top: 12px; min-height: 22px; font-size: 13.5px; color: var(--muted); }
.merge-applied b { color: var(--accent-2); font-family: var(--mono); }
.merge-table-details { margin-top: 14px; }
.merge-table-details summary { cursor: pointer; color: var(--accent); font-size: 12.5px; }
.merge-table-wrap { max-height: 280px; overflow: auto; margin-top: 10px; border: 1px solid var(--border); border-radius: 10px; }
.merge-table { width: 100%; border-collapse: collapse; font-size: 12.5px; }
.merge-table th { position: sticky; top: 0; background: var(--panel-2); color: var(--muted);
  text-align: left; padding: 7px 10px; font-weight: 600; border-bottom: 1px solid var(--border); }
.merge-table td { padding: 5px 10px; border-bottom: 1px solid #ffffff0a; font-family: var(--mono); }
.merge-table tr.cur td { background: #7c8cff22; }
.merge-table .arrow { color: var(--muted); }
.merge-table .mtok { color: var(--accent-2); }
.merge-panel.disabled { opacity: .45; pointer-events: none; }

footer { max-width: 980px; margin: 30px auto 0; color: var(--muted); font-size: 12px; text-align: center; }

/* help button */
.help-btn {
  display: inline-flex; align-items: center; justify-content: center;
  width: 18px; height: 18px; border-radius: 99px; background: var(--panel-2);
  border: 1px solid var(--border); color: var(--muted); font-size: 10px;
  font-weight: 700; cursor: pointer; vertical-align: middle; margin-left: 6px; transition: .12s;
}
.help-btn:hover { color: var(--accent); border-color: var(--accent); }

/* =========================================================== GUIDE */
.guide {
  max-width: 980px; margin: 0 auto; padding: 30px 0 80px;
  display: grid; grid-template-columns: 1fr 220px; gap: 0 48px;
}

.guide-toc {
  grid-column: 2; grid-row: 1 / 30; position: sticky; top: 20px;
  background: var(--panel); border: 1px solid var(--border); border-radius: 12px;
  padding: 16px; display: flex; flex-direction: column; gap: 4px; align-self: start;
}
.toc-label {
  font-size: 10px; text-transform: uppercase; letter-spacing: 1px; color: var(--muted);
  font-weight: 700; margin-bottom: 6px;
}
.guide-toc a {
  color: var(--muted); text-decoration: none; font-size: 12.5px; padding: 5px 8px;
  border-radius: 6px; transition: .1s; line-height: 1.3;
}
.guide-toc a:hover { color: var(--text); background: var(--panel-2); }

.chapter {
  grid-column: 1; padding: 0 0 48px;
  border-bottom: 1px solid var(--border); margin-bottom: 48px;
}
.chapter:last-of-type { border-bottom: none; }

.chapter h2 {
  font-size: 22px; margin: 0 0 18px; display: flex; align-items: center; gap: 12px;
  letter-spacing: -0.3px;
}
.ch-num {
  display: inline-flex; align-items: center; justify-content: center;
  width: 32px; height: 32px; border-radius: 99px; background: var(--accent);
  color: #0b0d14; font-size: 14px; font-weight: 800; flex-shrink: 0;
}
.chapter h3 { font-size: 15px; margin: 24px 0 8px; color: var(--accent-2); font-weight: 700; }
.chapter p { margin: 0 0 14px; line-height: 1.7; color: #ced3de; font-size: 15px; }
.chapter code {
  font-family: var(--mono); font-size: 13px; background: var(--panel-2);
  padding: 1px 5px; border-radius: 4px; color: var(--accent-2);
}
.chapter strong { color: var(--text); }

/* token demo blocks inside guide */
.token-demo {
  display: flex; flex-wrap: wrap; gap: 6px; align-items: center;
  background: var(--panel); border: 1px solid var(--border); border-radius: 10px;
  padding: 12px 14px; margin: 14px 0;
}
.token-demo.small .tok { font-size: 13px; padding: 3px 5px; }
.demo-label { width: 100%; font-size: 11.5px; color: var(--muted); margin-top: 6px; }
.step-freq {
  font-family: var(--mono); font-size: 12px; color: var(--muted);
  padding: 0 8px; border-right: 1px solid var(--border); margin-right: 4px;
}

/* callouts */
.callout {
  border-radius: 10px; padding: 14px 16px; margin: 20px 0;
  font-size: 14px; line-height: 1.65; color: #ced3de;
}
.callout strong {
  display: block; margin-bottom: 5px; font-size: 12px;
  text-transform: uppercase; letter-spacing: .6px;
}
.cite-link {
  display: inline-block; margin-top: 8px; font-size: 12px; font-family: var(--mono);
  color: var(--accent); text-decoration: none; opacity: .8;
}
.cite-link:hover { opacity: 1; text-decoration: underline; }
.callout.insight { background: #7c8cff18; border-left: 3px solid var(--accent); }
.callout.insight strong { color: var(--accent); }
.callout.warn { background: #ffc06b18; border-left: 3px solid #ffc06b; }
.callout.warn strong { color: #ffc06b; }

/* try-it buttons */
.try-it {
  display: inline-block; margin-top: 10px; padding: 10px 18px; border-radius: 9px;
  background: var(--panel-2); border: 1px solid var(--border); color: var(--accent);
  font-size: 13.5px; font-weight: 600; cursor: pointer; transition: .14s;
}
.try-it:hover { background: #7c8cff22; border-color: var(--accent); }
.try-it.large {
  font-size: 15px; padding: 14px 28px;
  background: var(--accent); color: #0b0d14; border-color: var(--accent);
}
.try-it.large:hover { filter: brightness(1.1); }

/* step list */
.step-list { padding-left: 0; list-style: none; counter-reset: step; margin: 14px 0; }
.step-list li {
  counter-increment: step; display: flex; gap: 14px; align-items: flex-start;
  margin-bottom: 18px; font-size: 15px; color: #ced3de; line-height: 1.65;
}
.step-list li::before {
  content: counter(step); display: inline-flex; align-items: center; justify-content: center;
  width: 26px; height: 26px; border-radius: 99px; background: var(--panel-2);
  border: 1px solid var(--border); font-weight: 700; font-size: 12px;
  color: var(--accent); flex-shrink: 0; margin-top: 2px;
}
.step-list li > div { flex: 1; }

/* tradeoff table */
.tradeoff-table {
  background: var(--panel); border: 1px solid var(--border); border-radius: 12px;
  overflow: hidden; margin: 18px 0; font-size: 13px;
}
.tradeoff-head, .tradeoff-row {
  display: grid; grid-template-columns: 160px 1fr 1fr 1fr;
  border-bottom: 1px solid var(--border);
}
.tradeoff-row:last-child { border-bottom: none; }
.tradeoff-head { background: var(--panel-2); font-weight: 700; color: var(--muted); font-size: 12px; }
.tradeoff-head > div, .tradeoff-row > div { padding: 10px 12px; line-height: 1.4; }
.tl-small { color: var(--tok0b); } .tl-mid { color: var(--tok1b); } .tl-large { color: var(--tok2b); }
.tl-eg { font-weight: 400; color: var(--muted); font-size: 11px; display: block; }
.tl-label { color: var(--muted); font-weight: 600; }
.tl-bad { color: #ff9090; } .tl-mid2 { color: #ffc06b; }
.tl-good { color: var(--good); } .tl-warn { color: #ffc06b; }

/* ---- embedding lookup diagram (ch5) ------------------------------------ */
.embed-lookup-diagram {
  display: flex; align-items: flex-start; gap: 12px; background: var(--panel);
  border: 1px solid var(--border); border-radius: 12px; padding: 18px 16px;
  margin: 20px 0; flex-wrap: wrap; overflow-x: auto;
}
.eld-col { display: flex; flex-direction: column; gap: 8px; min-width: 80px; }
.eld-label { font-size: 10px; text-transform: uppercase; letter-spacing: .7px;
  color: var(--muted); white-space: nowrap; }
.embed-dim { color: var(--accent); font-size: 10px; }
.eld-ids { display: flex; flex-wrap: wrap; gap: 4px; }
.eld-table-col { flex: 1 1 220px; }
.eld-table { display: flex; flex-direction: column; gap: 3px; }
.eld-row { display: flex; align-items: center; gap: 8px; font-family: var(--mono);
  font-size: 11px; padding: 4px 6px; border-radius: 5px; color: var(--muted); }
.eld-row.faded { opacity: .35; }
.eld-row.active { background: #7c8cff0f; }
.eld-bar-row { display: flex; gap: 3px; flex: 1; }
.eld-bar { height: 10px; border-radius: 2px; flex-shrink: 0; }
.eld-arrow { font-size: 18px; color: var(--muted); align-self: center; padding: 0 2px; }
.eld-vecs { display: flex; gap: 6px; }
.eld-vec { display: flex; flex-direction: column; gap: 3px; border-radius: 6px; padding: 4px; }
.eld-vec.c2 { background: var(--tok2); }
.eld-vec.c3 { background: var(--tok3); }
.eld-vec.c5 { background: var(--tok5); }
.eld-vec.c6 { background: var(--tok6); }
.eld-vec div { width: 10px; height: 14px; border-radius: 2px; background: currentColor; opacity: .7; }
.eld-transformer { display: flex; flex-direction: column; gap: 3px; }
.eld-block { font-size: 11px; background: var(--panel-2); border: 1px solid var(--border);
  border-radius: 5px; padding: 5px 10px; color: var(--muted); text-align: center; white-space: nowrap; }
.eld-head { color: var(--accent-2); border-color: var(--accent-2); }

/* ---- neighbor comparison (ch5) ----------------------------------------- */
.neighbor-compare {
  display: grid; grid-template-columns: 1fr 1fr; gap: 14px; margin: 20px 0;
}
.nc-col { background: var(--panel); border: 1px solid var(--border); border-radius: 12px; overflow: hidden; }
.nc-head { font-size: 12px; font-weight: 700; padding: 10px 14px;
  background: var(--panel-2); border-bottom: 1px solid var(--border); color: var(--muted); }
.nc-head em { color: var(--accent-2); font-style: normal; }
.nc-body { padding: 12px 14px; }
.nc-note { font-size: 13px; color: #ced3de; margin: 0 0 12px; line-height: 1.55; }
.nc-neighbors { display: flex; flex-direction: column; gap: 5px; margin-bottom: 10px; }
.nc-row { display: flex; align-items: center; gap: 8px; }
.nc-bar-wrap { flex: 1; background: var(--panel-2); border-radius: 4px; height: 16px; overflow: hidden; border: 1px solid var(--border); }
.nc-bar { height: 100%; background: var(--accent); opacity: .6; border-radius: 4px; }
.nc-sim { font-family: var(--mono); font-size: 11px; color: var(--muted); width: 34px; text-align: right; }
.nc-verdict { font-size: 12px; margin: 0; padding: 8px 10px; border-radius: 7px; font-weight: 600; }
.nc-verdict.bad { background: #ff909018; color: #ff9090; }
.nc-verdict.good { background: #5be08a18; color: var(--good); }
.inline-tok {
  display: inline-block; font-family: var(--mono); font-size: 13px;
  padding: 2px 5px; border-radius: 5px; border: 1px solid #ffffff14;
}
.inline-tok.c0 { background: var(--tok0); color: var(--tok0b); }
.inline-tok.c1 { background: var(--tok1); color: var(--tok1b); }
.inline-tok.c2 { background: var(--tok2); color: var(--tok2b); }
.inline-tok.c3 { background: var(--tok3); color: var(--tok3b); }
.inline-tok.c4 { background: var(--tok4); color: var(--tok4b); }
.inline-tok.c5 { background: var(--tok5); color: var(--tok5b); }
.inline-tok.c6 { background: var(--tok6); color: var(--tok6b); }
.inline-tok.c7 { background: var(--tok7); color: var(--tok7b); }

/* ---- swap diagram (ch5 guide) ------------------------------------------ */
.swap-diagram {
  display: grid; grid-template-columns: 1fr 1fr; gap: 14px; margin: 20px 0;
}
.sd-col { background: var(--panel); border: 1px solid var(--border); border-radius: 12px;
  padding: 14px 16px; display: flex; flex-direction: column; gap: 7px; }
.sd-correct { border-color: var(--good); }
.sd-wrong { border-color: #ff9090; }
.sd-badge { font-size: 11px; font-weight: 800; text-transform: uppercase;
  letter-spacing: .8px; margin-bottom: 2px; }
.sd-badge.ok { color: var(--good); }
.sd-badge.bad { color: #ff9090; }
.sd-step { font-size: 13px; color: #ced3de; line-height: 1.5; }
.sd-step code { font-size: 11.5px; }
.sd-preds { margin-top: 6px; border-top: 1px solid var(--border); padding-top: 8px; }
.sd-pred-label { font-size: 10px; text-transform: uppercase; letter-spacing: .6px;
  color: var(--muted); margin-bottom: 6px; }
.sd-pred-row { display: flex; justify-content: space-between; font-family: var(--mono);
  font-size: 12.5px; padding: 3px 0; color: var(--muted); }
.sd-pct { font-weight: 700; }
.sd-pct.good { color: var(--good); }
.sd-pct.bad { color: #ff9090; }

/* ---- embedding neighbors playground panel -------------------------------- */
.neighbors-content { min-height: 40px; }
.neighbor-result { display: flex; align-items: flex-start; gap: 16px; flex-wrap: wrap; }
.nr-query { display: flex; flex-direction: column; gap: 6px; }
.nr-query-label { font-size: 10px; text-transform: uppercase; letter-spacing: .7px; color: var(--muted); }
.nr-list { display: flex; flex-direction: column; gap: 5px; flex: 1; min-width: 200px; }
.nr-row { display: flex; align-items: center; gap: 8px; }
.nr-sim-bar { flex: 1; background: var(--panel-2); border-radius: 4px; height: 18px;
  overflow: hidden; border: 1px solid var(--border); }
.nr-sim-fill { height: 100%; border-radius: 4px; background: linear-gradient(90deg, var(--accent), var(--accent-2)); transition: width .3s ease; }
.nr-sim-val { font-family: var(--mono); font-size: 11px; color: var(--muted); width: 34px; text-align: right; }
.nr-char-note { font-size: 12px; color: var(--muted); font-style: italic; margin-top: 6px; }

/* ---- swap experiment playground panel ------------------------------------ */
.swap-controls { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
.swap-select {
  background: var(--panel-2); color: var(--text); border: 1px solid var(--border);
  border-radius: 7px; padding: 5px 9px; font-size: 12px; cursor: pointer;
}
.swap-columns { display: grid; grid-template-columns: 1fr 1px 1fr; gap: 0 16px; margin-top: 12px; }
.swap-divider { background: var(--border); }
.swap-col { display: flex; flex-direction: column; gap: 6px; }
.swap-col-head { font-size: 11px; font-weight: 700; text-transform: uppercase;
  letter-spacing: .7px; padding-bottom: 8px; border-bottom: 1px solid var(--border); margin-bottom: 4px; }
.ok-head { color: var(--good); }
.bad-head { color: #ff9090; }
.swap-bars { gap: 4px; }
.swap-oob { font-size: 11.5px; color: #ffc06b; margin-top: 8px; min-height: 16px; }

@media (max-width: 760px) {
  .neighbor-compare, .swap-diagram { grid-template-columns: 1fr; }
  .swap-columns { grid-template-columns: 1fr; }
  .swap-divider { display: none; }
}

/* formula */
.formula-box {
  background: var(--panel); border: 1px solid var(--border); border-radius: 12px;
  padding: 20px 24px; margin: 18px 0; text-align: center;
}
.formula {
  font-size: 20px; font-family: Georgia, "Times New Roman", serif;
  color: var(--text); margin-bottom: 14px; display: flex;
  align-items: center; justify-content: center; gap: 8px; flex-wrap: wrap;
}
.frac { display: inline-flex; flex-direction: column; align-items: center; font-size: 14px; vertical-align: middle; }
.frac-top { border-bottom: 1px solid var(--text); padding-bottom: 2px; }
.frac-bot { padding-top: 2px; }
.formula-note { font-size: 13px; color: var(--muted); line-height: 1.6; }

/* real-world grid */
.real-world-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; margin: 18px 0; }
.rw-card { background: var(--panel); border: 1px solid var(--border); border-radius: 12px; padding: 16px; }
.rw-name { font-weight: 800; font-size: 15px; margin-bottom: 4px; }
.rw-used { font-size: 11.5px; color: var(--accent-2); font-family: var(--mono); margin-bottom: 10px; }
.rw-card p { font-size: 13.5px; color: #ced3de; line-height: 1.6; margin: 0; }

/* panel guide */
.panel-guide-item {
  background: var(--panel); border: 1px solid var(--border); border-radius: 12px;
  padding: 14px 16px; margin-bottom: 12px;
}
.pgi-label { font-size: 11px; text-transform: uppercase; letter-spacing: .8px;
  font-weight: 700; color: var(--accent); margin-bottom: 8px; }
.panel-guide-item p { margin: 0; font-size: 14px; color: #ced3de; line-height: 1.65; }

/* guide end */
.guide-end { text-align: center; padding: 20px 0 0; }
.guide-end p { color: var(--muted); margin-bottom: 16px; }

/* responsive */
@media (max-width: 760px) {
  .guide { grid-template-columns: 1fr; }
  .guide-toc { grid-column: 1; grid-row: auto; position: static;
    display: grid; grid-template-columns: 1fr 1fr; }
  .toc-label { grid-column: 1 / -1; }
  .real-world-grid { grid-template-columns: 1fr; }
  .tradeoff-head, .tradeoff-row { grid-template-columns: 100px 1fr 1fr 1fr; }
}
@media (max-width: 560px) {
  .bar-row { grid-template-columns: 72px 1fr 46px; }
  .embed-diagram { flex-direction: column; align-items: flex-start; }
  .tradeoff-head, .tradeoff-row { grid-template-columns: 80px 1fr 1fr 1fr; font-size: 11px; }
  .tradeoff-head > div, .tradeoff-row > div { padding: 8px; }
}

.fig{margin:22px 0;background:var(--panel);border:1px solid var(--border);border-radius:12px;padding:18px 16px 12px}
.fig svg{display:block;width:100%;height:auto;overflow:visible}
.fig figcaption{margin-top:10px;font-size:12px;color:var(--muted);text-align:center;line-height:1.55}

/* offline notice — shown when the FastAPI server is not running */
.offline-notice{padding:28px 24px;max-width:620px;margin:32px auto}
.offline-notice p{margin:0 0 14px;line-height:1.65;color:var(--text)}
.offline-notice pre{background:var(--bg);border:1px solid var(--border);border-radius:8px;padding:14px 16px;font-size:13px;overflow-x:auto;margin:0 0 14px;color:var(--text)}
.offline-notice a{color:var(--accent)}
.offline-note{font-size:13px;color:var(--muted);margin:0 !important}