@import url('https://fonts.googleapis.com/css2?family=JetBrains+Mono:wght@400;500;600;700;800&display=swap');
/* ============================================================
   AI Knowledge Center — Concepts + Exam learning site.
   One stylesheet, linked by every concept/primitive/exam page.
   Aligned to the portfolio (vikkybharadwaj.github.io) and the
   Product Cockpit: JetBrains Mono, dark-only #0a0f1a canvas,
   glassy translucent cards, ambient glow, green→blue gradient.
   Variable names preserved so all existing rules keep working.
   ============================================================ */

:root {
  --bg:#0a0f1a; --bg-soft:#0f1626; --bg-card:rgba(17,24,39,.6); --bg-card-solid:#111827;
  --border:rgba(255,255,255,.08); --border-2:rgba(255,255,255,.18);
  --text:#e2e8f0; --text-soft:#94a3b8; --text-dim:#64748b;
  --accent:#00D26A;        /* green — primary */
  --accent-2:#4F8CFF;      /* blue — links */
  --accent-3:#2dd4bf;      /* teal — positive / GA */
  --accent-4:#a855f7;      /* purple — advanced */
  --warn:#f59e0b;          /* amber — experimental */
  --danger:#fb7185;        /* rose */
  --grad:linear-gradient(100deg,var(--accent),var(--accent-2));
  --radius:14px; --radius-sm:10px; --shadow:0 18px 50px rgba(0,0,0,.5);
  --maxw:1180px;
  --sans:'JetBrains Mono',ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;
  --mono:'JetBrains Mono',ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 84px; }
body {
  margin: 0; font-family: var(--sans); background: var(--bg); color: var(--text);
  line-height: 1.65; -webkit-font-smoothing: antialiased; font-size: 15.5px;
  letter-spacing: -.1px; overflow-x: hidden;
}
strong, b { color: var(--text); font-weight: 700; }

/* ambient glow blobs */
body::before, body::after { content:""; position:fixed; z-index:-1; pointer-events:none; border-radius:50%; filter:blur(120px); opacity:.16; }
body::before { top:-160px; left:-120px; width:520px; height:520px; background:radial-gradient(closest-side,var(--accent),transparent); }
body::after  { top:220px; right:-180px; width:560px; height:560px; background:radial-gradient(closest-side,var(--accent-2),transparent); }

/* ---------- sticky top nav (portfolio pattern) ---------- */
.nav, .topbar {
  position: sticky; top: 0; z-index: 50;
  background: rgba(10,15,26,.72); backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}
.nav .wrap, .topbar .wrap { display:flex; align-items:center; gap:6px; height:60px; }
.nav .brand, .topbar .brand {
  display:flex; align-items:center; gap:9px; margin-right:auto;
  font-weight:800; font-size:1rem; letter-spacing:-.5px; color:var(--text); white-space:nowrap;
}
.nav .brand:hover, .topbar .brand:hover { text-decoration:none; }
.nav .brand .dot, .topbar .brand .dot { width:11px; height:11px; border-radius:50%; background:var(--grad); box-shadow:0 0 0 4px rgba(0,210,106,.18); }
.nav .brand .accent { background:var(--grad); -webkit-background-clip:text; background-clip:text; -webkit-text-fill-color:transparent; }
.nav nav, .nav .navlinks { display:flex; align-items:center; gap:2px; }
.nav a, .topbar nav a {
  font-size:.78rem; color:var(--text-soft); padding:7px 11px; border-radius:8px;
  white-space:nowrap; text-decoration:none; transition:color .15s, background .15s;
}
.nav a:hover, .topbar nav a:hover { background:rgba(255,255,255,.05); color:var(--text); text-decoration:none; }
.nav a.active, .topbar nav a.active { background:var(--grad); color:#06120c; font-weight:700; }
.nav a.active:hover, .topbar nav a.active:hover { color:#06120c; box-shadow:0 8px 22px rgba(0,210,106,.25); text-decoration:none; }
/* Cross-view CTA — a distinct destination, NOT the active tab. Purple→blue so it never reads as "you are here". */
.nav .pill, .topbar nav a.cta { margin-left:8px; background:linear-gradient(100deg,var(--accent-4),var(--accent-2)); color:#fff; font-weight:700; }
.nav .pill:hover, .topbar nav a.cta:hover { color:#fff; box-shadow:0 8px 22px rgba(168,85,247,.30); text-decoration:none; }
.nav .sep { width:1px; height:20px; background:var(--border); margin:0 6px; flex:none; }
@media (max-width:760px){
  .nav .wrap, .topbar .wrap { overflow-x:auto; gap:2px; -webkit-overflow-scrolling:touch; }
  .nav .wrap::-webkit-scrollbar, .topbar .wrap::-webkit-scrollbar { display:none; }
  .nav a, .topbar nav a { padding:6px 9px; font-size:.74rem; }
  .nav .pill { margin-left:4px; }
}

/* ---------- layout ---------- */
.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 22px; }
main { padding: 38px 0 90px; }
.lede { max-width: 760px; }

section { margin: 46px 0; scroll-margin-top: 80px; }
h1 { font-size: clamp(2rem,5vw,2.6rem); line-height: 1.1; margin: .2em 0 .35em; letter-spacing: -1.2px; font-weight: 800; }
h2 { font-size: clamp(1.4rem,3vw,1.7rem); margin: 1.7em 0 .5em; letter-spacing: -.8px; font-weight: 800; }
h3 { font-size: 1.14rem; margin: 1.3em 0 .4em; letter-spacing: -.4px; font-weight: 700; }
p  { color: var(--text-soft); }
a  { color: var(--accent-2); text-decoration: none; }
a:hover { text-decoration: underline; }
code { font-family: var(--mono); font-size: .86em; background: rgba(255,255,255,.06);
  padding: 1.5px 6px; border-radius: 6px; color: #8fe7b8; border: 1px solid var(--border); }
pre { background: rgba(0,0,0,.32); border: 1px solid var(--border); border-radius: var(--radius-sm);
  padding: 16px 18px; overflow-x: auto; font-family: var(--mono); font-size: .82rem; line-height: 1.6; color: var(--text); }
pre code { background: none; border: none; padding: 0; color: var(--text); }
hr { border: none; border-top: 1px solid var(--border); margin: 34px 0; }

.eyebrow { font-family: var(--mono); text-transform: uppercase; letter-spacing: .2em; font-size: .7rem;
  color: var(--accent); font-weight: 700; margin-bottom: 10px; }

/* ---------- hero ---------- */
.hero { padding: 40px 0 8px; }
.hero h1 { font-size: clamp(2.2rem,6vw,3.2rem); letter-spacing: -2px; }
.hero h1 .grad, .grad-text { background: var(--grad); -webkit-background-clip:text; background-clip:text; -webkit-text-fill-color:transparent; }
.hero .sub { font-size: 1.08rem; color: var(--text-soft); max-width: 720px; line-height: 1.75; }

/* ---------- cards / grids ---------- */
.grid { display: grid; gap: 18px; }
.grid.cols-2 { grid-template-columns: repeat(2, 1fr); }
.grid.cols-3 { grid-template-columns: repeat(3, 1fr); }
.grid.cols-4 { grid-template-columns: repeat(4, 1fr); }
@media (max-width: 880px) { .grid.cols-2, .grid.cols-3, .grid.cols-4 { grid-template-columns: 1fr; } }

.card {
  background: var(--bg-card); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 22px 24px; position: relative;
  backdrop-filter: blur(8px);
  transition: transform .15s ease, border-color .2s ease, box-shadow .2s ease;
}
.card:hover { transform: translateY(-4px); border-color: var(--border-2); box-shadow: 0 18px 50px rgba(0,210,106,.1); }
.card h3 { margin-top: 0; }
.card .meta { font-family: var(--mono); font-size: .72rem; color: var(--text-dim); }
a.card { display: block; color: inherit; text-decoration: none; }
a.card:hover { text-decoration: none; }
.card .arrow { position: absolute; top: 18px; right: 20px; color: var(--text-dim); transition: transform .15s, color .15s; }
a.card:hover .arrow { transform: translateX(3px); color: var(--accent); }

/* ---------- badges ---------- */
.badge {
  display: inline-flex; align-items: center; gap: 5px;
  font-family: var(--mono); font-size: .66rem; font-weight: 700; letter-spacing: .04em;
  padding: 3px 9px; border-radius: 999px; border: 1px solid var(--border-2);
  color: var(--text-soft); background: rgba(255,255,255,.03); white-space: nowrap;
}
.badge.l101 { color: var(--accent-3); border-color: color-mix(in srgb, var(--accent-3) 45%, transparent); }
.badge.l201 { color: var(--accent-2); border-color: color-mix(in srgb, var(--accent-2) 45%, transparent); }
.badge.l301 { color: var(--accent-4); border-color: color-mix(in srgb, var(--accent-4) 45%, transparent); }
.badge.ga   { color: var(--accent-3); }
.badge.preview { color: var(--warn); }
.badge.exp  { color: var(--danger); }
.badge.det  { color: var(--accent-2); }
.badge.model{ color: var(--accent); }
.badge.idbadge { cursor: help; text-decoration: underline dotted; text-underline-offset: 2px; }

/* ---------- tooltip (hoverable definitions) ---------- */
.tip { border-bottom: 1px dashed var(--accent); cursor: help; position: relative; color: var(--text); }
.tip:hover::after, .tip:focus::after {
  content: attr(data-tip);
  position: absolute; left: 50%; bottom: 145%; transform: translateX(-50%);
  width: max-content; max-width: 320px; white-space: normal;
  background: var(--bg-card-solid); color: var(--text-soft);
  border: 1px solid var(--border-2); border-radius: 10px; padding: 10px 13px;
  font-size: .82rem; line-height: 1.5; box-shadow: var(--shadow); z-index: 60; text-align: left;
}
.tip:hover::before, .tip:focus::before {
  content: ""; position: absolute; left: 50%; bottom: 145%; transform: translate(-50%, 99%) rotate(45deg);
  width: 9px; height: 9px; background: var(--bg-card-solid); border-right: 1px solid var(--border-2);
  border-bottom: 1px solid var(--border-2); z-index: 61;
}

/* ---------- accordions (click to expand deep dives) ---------- */
details.acc {
  background: var(--bg-card); border: 1px solid var(--border);
  border-radius: var(--radius-sm); margin: 12px 0; overflow: hidden; backdrop-filter: blur(8px);
}
details.acc > summary {
  cursor: pointer; padding: 15px 18px; font-weight: 700; list-style: none;
  display: flex; align-items: center; gap: 10px; user-select: none;
}
details.acc > summary::-webkit-details-marker { display: none; }
details.acc > summary::before {
  content: "▸"; color: var(--accent); transition: transform .18s; display: inline-block;
}
details.acc[open] > summary::before { transform: rotate(90deg); }
details.acc > summary:hover { background: rgba(255,255,255,.03); }
details.acc .acc-body { padding: 4px 18px 18px; border-top: 1px solid var(--border); }
details.acc .acc-body > *:first-child { margin-top: 12px; }

/* ---------- worked mini-cases (situation → trap → answer → principle) ---------- */
.mc-q { color: var(--text); }
.mc-trap, .mc-ans { display: grid; grid-template-columns: 70px 1fr; gap: 12px; margin: 9px 0; align-items: baseline; }
.mc-trap .tag, .mc-ans .tag { font-family: var(--mono); font-size: .62rem; font-weight: 700; text-transform: uppercase; letter-spacing: .06em;
  padding-top: 2px; }
.mc-trap .tag { color: var(--danger); }
.mc-ans   .tag { color: var(--accent-3); }
.mc-trap > div:last-child { color: var(--text-soft); }
.principle { margin: 13px 0 2px; border-left: 3px solid var(--accent-4); background: rgba(255,255,255,.03);
  padding: 10px 15px; border-radius: 0 var(--radius-sm) var(--radius-sm) 0; font-size: .9rem; }
.principle .label { font-family: var(--mono); font-weight: 700; font-size: .62rem; text-transform: uppercase; letter-spacing: .1em;
  color: var(--accent-4); margin-right: 9px; }
@media (max-width: 560px){ .mc-trap, .mc-ans { grid-template-columns: 1fr; gap: 2px; } }

/* ---------- tables ---------- */
.table-wrap { overflow-x: auto; border: 1px solid var(--border); border-radius: var(--radius); }
.matrix-scroll { max-height: 78vh; overflow: auto; }
table { border-collapse: collapse; width: 100%; font-size: .85rem; }
th, td { text-align: left; padding: 11px 14px; border-bottom: 1px solid var(--border); vertical-align: top; }
th { background: var(--bg-card-solid); color: var(--text); font-weight: 700; font-family: var(--mono); font-size: .7rem; letter-spacing: .04em; text-transform: uppercase; position: sticky; top: 0; z-index: 2; }
tbody tr:hover { background: rgba(255,255,255,.025); }
td:first-child, th:first-child { position: sticky; left: 0; background: var(--bg-card-solid); z-index: 1; }
th:first-child { background: var(--bg-card-solid); z-index: 3; }
td:first-child { font-weight: 700; color: var(--text); }
.cell-good { color: var(--accent-3); }
.cell-warn { color: var(--warn); }
.cell-bad  { color: var(--danger); }

/* ---------- callouts ---------- */
.callout { border-left: 3px solid var(--accent); background: rgba(255,255,255,.03);
  padding: 13px 17px; border-radius: 0 var(--radius-sm) var(--radius-sm) 0; margin: 18px 0; }
.callout.tip-c    { border-color: var(--accent-3); }
.callout.warn-c   { border-color: var(--warn); }
.callout.key      { border-color: var(--accent-4); }
.callout .label { font-family: var(--mono); font-weight: 700; font-size: .66rem; text-transform: uppercase; letter-spacing: .1em;
  color: var(--accent); display: block; margin-bottom: 4px; }
.callout.tip-c .label { color: var(--accent-3); }
.callout.warn-c .label { color: var(--warn); }
.callout.key .label { color: var(--accent-4); }

/* ---------- "when to reach for it" mini-rows ---------- */
.usewhen { display: grid; grid-template-columns: 22px 1fr; gap: 10px; margin: 7px 0; align-items: start; }
.usewhen .ic { color: var(--accent-3); }
.usewhen.no .ic { color: var(--danger); }

/* ---------- analogy chip ---------- */
.analogy { font-style: italic; color: var(--text-soft); }
.analogy strong { color: var(--accent); font-style: normal; }

/* ---------- step flow ---------- */
.flow { display: flex; align-items: stretch; gap: 0; flex-wrap: wrap; }
.flow .step { flex: 1; min-width: 150px; background: var(--bg-card); border: 1px solid var(--border);
  border-radius: var(--radius-sm); padding: 14px 16px; position: relative; backdrop-filter: blur(8px); }
.flow .step + .step { margin-left: 26px; }
.flow .step + .step::before { content: "→"; position: absolute; left: -22px; top: 50%;
  transform: translateY(-50%); color: var(--accent); font-size: 20px; }
.flow .step .n { font-family: var(--mono); font-size: .7rem; color: var(--accent); font-weight: 700; }
@media (max-width: 720px){ .flow { flex-direction: column; } .flow .step + .step { margin-left: 0; margin-top: 26px; }
  .flow .step + .step::before { left: 50%; top: -22px; transform: translateX(-50%); } }

/* ---------- the four levels of control (prompt ⊂ context ⊂ harness ⊂ loop) ----------
   One uniform template per level: a left accent rail, a mono tag, a lede, and a
   four-fact grid (the unit · you engineer · fix here when · in Claude Code). Loop
   shares the same head, then carries its deeper material below the grid. */
.level { position: relative; padding-left: 24px; margin: 30px 0 0; border-left: 3px solid var(--accent); }
.level.lv-loop { border-color: var(--accent-4); }
.level .lv-tag { font-family: var(--mono); font-size: .68rem; font-weight: 700; letter-spacing: .14em;
  text-transform: uppercase; color: var(--accent); }
.level.lv-loop .lv-tag { color: var(--accent-4); }
.level > h2 { margin: .12em 0 .3em; }
.level .lv-lede { color: var(--text); font-size: 1.02rem; max-width: 760px; margin: 0 0 4px; }
.level .lv-facts { display: grid; grid-template-columns: 1fr 1fr; gap: 13px 30px; margin: 16px 0 4px; }
@media (max-width: 720px){ .level .lv-facts { grid-template-columns: 1fr; } }
.level .fact .k { font-family: var(--mono); font-size: .62rem; font-weight: 700; text-transform: uppercase;
  letter-spacing: .1em; color: var(--text-dim); display: block; margin-bottom: 3px; }
.level.lv-loop .fact .k { color: color-mix(in srgb, var(--accent-4) 70%, var(--text-dim)); }
.level .fact .v { color: var(--text-soft); font-size: .9rem; line-height: 1.55; }
.level .fact .v strong { color: var(--text); }

/* ---------- footer ---------- */
footer { border-top: 1px solid var(--border); margin-top: 60px; padding: 30px 0 60px; color: var(--text-dim); font-size: .86rem; }
footer a { color: var(--text-soft); }

/* ---------- breadth/depth bars ---------- */
.bar { height: 8px; background: rgba(255,255,255,.04); border-radius: 99px; overflow: hidden; border: 1px solid var(--border); }
.bar > span { display: block; height: 100%; background: var(--grad); }

/* ---------- on-page TOC ---------- */
.layout { display: grid; grid-template-columns: 220px minmax(0, 1fr); gap: 40px; align-items: start; }
/* grid items default to min-width:auto, which lets a wide table balloon the column past 1fr
   so .matrix-scroll never gets to scroll. min-width:0 lets the column shrink and hand the
   overflow to the inner .table-wrap. */
.layout > * { min-width: 0; }
.toc { position: sticky; top: 80px; font-size: .82rem; }
.toc a { display: block; color: var(--text-dim); padding: 4px 10px; border-left: 2px solid var(--border); }
.toc a:hover, .toc a.active { color: var(--accent); border-color: var(--accent); text-decoration: none; }
@media (max-width: 940px){ .layout { grid-template-columns: 1fr; } .toc { display: none; } }

.pill-row { display: flex; gap: 8px; flex-wrap: wrap; margin: 10px 0 4px; }
.pill-row .legend-link { align-self: center; font-size: .72rem; color: var(--text-dim); text-decoration: none; }
.pill-row .legend-link:hover { color: var(--accent); text-decoration: underline; }
.tags { display:flex; gap:6px; flex-wrap:wrap; margin-top:10px; }
.tags span { font-family: var(--mono); font-size: .68rem; background: rgba(255,255,255,.025); border: 1px solid var(--border); border-radius: 999px; padding: 4px 10px; color: var(--text-soft); }

/* ============================================================
   Quiz / exam-prep engine
   ============================================================ */
.quiz-controls { display:flex; gap:10px; flex-wrap:wrap; align-items:center; margin:18px 0; }
.quiz-controls select, .quiz-controls button {
  font-family: var(--sans); font-size:.82rem; padding:8px 12px; border-radius:9px;
  border:1px solid var(--border-2); background:var(--bg-card); color:var(--text); cursor:pointer;
}
.quiz-controls button.primary { background:var(--grad); color:#06120c; border:none; font-weight:700; }
.quiz-controls button.primary:hover { box-shadow:0 8px 22px rgba(0,210,106,.25); }
.quiz-controls button:hover { border-color:var(--accent); }
.quiz-controls .grow { flex:1; }

.quiz-stat { display:flex; gap:18px; flex-wrap:wrap; font-size:.85rem; color:var(--text-soft); margin-bottom:10px; }
.quiz-stat b { color:var(--text); }

.qcard { background:var(--bg-card); border:1px solid var(--border); border-radius:var(--radius); padding:22px 24px; backdrop-filter:blur(8px); }
.qcard .qmeta { display:flex; gap:8px; flex-wrap:wrap; margin-bottom:12px; }
.qcard .scenario { background:rgba(79,140,255,.08); border-left:3px solid var(--accent-2); padding:12px 16px;
  border-radius:0 9px 9px 0; margin:0 0 14px; color:var(--text-soft); }
.qcard .stem { font-weight:600; font-size:1.06rem; margin:6px 0 16px; color:var(--text); }

.options { display:flex; flex-direction:column; gap:10px; }
.option { display:flex; gap:12px; align-items:flex-start; padding:13px 15px; border:1px solid var(--border-2);
  border-radius:10px; cursor:pointer; transition:border-color .12s, background .12s; }
.option:hover { border-color:var(--accent); }
.option .key { font-weight:700; color:var(--text-dim); min-width:18px; }
.option.selected { border-color:var(--accent-2); background:color-mix(in srgb, var(--accent-2) 12%, transparent); }
.option.correct { border-color:var(--accent-3); background:color-mix(in srgb, var(--accent-3) 16%, transparent); }
.option.wrong { border-color:var(--danger); background:color-mix(in srgb, var(--danger) 14%, transparent); }
.option.disabled { cursor:default; }
.option .mark { margin-left:auto; font-weight:700; }
.option.correct .mark { color:var(--accent-3); }
.option.wrong .mark { color:var(--danger); }

.explain { margin-top:16px; border-top:1px solid var(--border); padding-top:14px; display:none; }
.explain.show { display:block; }
.explain .verdict { font-weight:700; margin-bottom:6px; }
.explain .verdict.ok { color:var(--accent-3); }
.explain .verdict.no { color:var(--danger); }
.explain .src { font-size:.78rem; color:var(--text-dim); margin-top:8px; }

.qnav { display:flex; justify-content:space-between; gap:10px; margin-top:18px; }
.scorebar { height:8px; background:rgba(255,255,255,.04); border:1px solid var(--border); border-radius:99px; overflow:hidden; margin:6px 0 2px; }
.scorebar > span { display:block; height:100%; background:var(--grad); width:0; transition:width .3s; }
.result-card { text-align:center; padding:34px; }
.result-card .big { font-size:3rem; font-weight:800; letter-spacing:-1.5px; }
.result-card .big.pass { background:var(--grad); -webkit-background-clip:text; background-clip:text; -webkit-text-fill-color:transparent; }
.result-card .big.fail { color:var(--warn); }
.domain-breakdown td.s { text-align:right; }