:root{
    --bg:#f5f7fb; --pane:#ffffff; --ink:#1f2733; --ink-soft:#516072; --line:#e6eaf1;
    --sidebar:#0d1424; --sidebar-2:#131c30; --sidebar-ink:#c7d2e2; --sidebar-dim:#7d8aa3;
    --code-bg:#0f1830; --code-ink:#dbe4f5; --chip:#eef2f9;
    --ok:#16a34a; --shaky:#d97706; --blank:#e11d48;
    --shadow:0 1px 2px rgba(16,24,40,.06),0 8px 24px rgba(16,24,40,.06);
    --radius:14px;
  }
  *{box-sizing:border-box}
  html{scroll-behavior:smooth}
  body{margin:0;background:var(--bg);color:var(--ink);
    font-family:'Inter',system-ui,-apple-system,Segoe UI,Roboto,sans-serif;
    font-size:19px;line-height:1.62;-webkit-font-smoothing:antialiased}
  a{color:inherit}
  code,kbd,pre{font-family:'JetBrains Mono','SF Mono',Menlo,Consolas,monospace}

  /* ---------- Layout ---------- */
  .wrap{display:grid;grid-template-columns:288px minmax(0,1fr);min-height:100vh}
  .rail{position:sticky;top:0;align-self:start;height:100vh;overflow-y:auto;
    background:linear-gradient(180deg,var(--sidebar),var(--sidebar-2));
    color:var(--sidebar-ink);padding:22px 16px 40px;border-right:1px solid #0a0f1c}
  .main{padding:0 clamp(16px,4vw,56px) 120px;max-width:1120px}

  /* ---------- Sidebar ---------- */
  .brand{display:flex;gap:11px;align-items:center;margin:4px 6px 16px}
  .brand .logo{width:38px;height:38px;border-radius:10px;flex:0 0 auto;
    background:conic-gradient(from 210deg,#6366f1,#22c55e,#f59e0b,#ec4899,#06b6d4,#6366f1);
    display:grid;place-items:center;font-weight:700;color:#0d1424;font-family:'Space Grotesk';font-size:18.4px;
    box-shadow:0 0 0 1px rgba(255,255,255,.08),0 6px 18px rgba(99,102,241,.35)}
  .brand h1{font:600 18.4px/1.15 'Space Grotesk';margin:0;color:#fff;letter-spacing:.2px}
  .brand p{margin:2px 0 0;font-size:14.1px;color:var(--sidebar-dim)}

  .searchbox{position:relative;margin:8px 6px 14px}
  .searchbox input{width:100%;padding:10px 12px 10px 34px;border-radius:10px;border:1px solid #223052;
    background:#0b122480;color:#eaf0fb;font-size:15.9px;outline:none}
  .searchbox input::placeholder{color:#61708f}
  .searchbox input:focus{border-color:#4763a8;box-shadow:0 0 0 3px rgba(71,99,168,.25)}
  .searchbox svg{position:absolute;left:11px;top:50%;transform:translateY(-50%);opacity:.55}

  .ctl{display:flex;gap:6px;margin:0 6px 16px}
  .ctl button{flex:1;font-size:14.1px;font-weight:600;color:#c7d2e2;background:#16203a;
    border:1px solid #26355a;border-radius:8px;padding:7px 4px;cursor:pointer;transition:.15s}
  .ctl button:hover{background:#1e2b4c;color:#fff}

  .nav a{display:flex;align-items:center;gap:10px;padding:7px 9px;border-radius:9px;
    color:var(--sidebar-ink);text-decoration:none;font-size:15.9px;font-weight:500;transition:.13s}
  .nav a:hover{background:#18223c;color:#fff}
  .nav a.active{background:#1c2743;color:#fff}
  .nav a.active .dot{box-shadow:0 0 0 3px rgba(255,255,255,.12)}
  .nav .dot{width:9px;height:9px;border-radius:50%;flex:0 0 auto;background:var(--c,#888)}
  .nav .ico{width:20px;text-align:center;font-size:17.2px;flex:0 0 auto}
  .nav .lbl{flex:1;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
  .nav .cnt{font-size:12.9px;color:var(--sidebar-dim);background:#141d33;border-radius:20px;padding:1px 7px}
  .nav .grouphead{margin:16px 9px 6px;font-size:12.9px;letter-spacing:.14em;text-transform:uppercase;color:#5b6a8a}

  .legend{margin:20px 6px 6px;padding:12px;border:1px solid #202c4a;border-radius:11px;background:#101a30}
  .legend .lt{font-size:12.9px;letter-spacing:.1em;text-transform:uppercase;color:#5b6a8a;margin-bottom:9px}
  .legend .row{display:flex;justify-content:space-between;align-items:center;font-size:14.7px;margin:6px 0}
  .legend .pill{width:26px;text-align:center;border-radius:6px;font-weight:700;font-size:13.5px;padding:2px 0}
  .p-ok{background:rgba(22,163,74,.18);color:#4ade80}
  .p-sh{background:rgba(217,119,6,.2);color:#fbbf24}
  .p-bl{background:rgba(225,29,72,.2);color:#fb7185}
  .legend b{color:#eaf0fb}

  /* ---------- Hero ---------- */
  .hero{margin:34px 0 8px;padding:30px 32px;border-radius:20px;position:relative;overflow:hidden;color:#fff;
    background:radial-gradient(1200px 300px at 0% -20%,#3b3f8f 0%,transparent 60%),linear-gradient(120deg,#111a35,#1c1350 55%,#0f2a44)}
  .hero:after{content:"";position:absolute;inset:0;
    background:linear-gradient(90deg,transparent,transparent 96%,rgba(255,255,255,.04)),
    linear-gradient(0deg,transparent,transparent 96%,rgba(255,255,255,.04));background-size:24px 24px;opacity:.5}
  .hero .eyebrow{font:600 14.1px/1 'Space Grotesk';letter-spacing:.22em;text-transform:uppercase;color:#9fb0ff;position:relative}
  .hero h2{font:700 36.8px/1.1 'Space Grotesk';margin:12px 0 6px;position:relative}
  .hero p{margin:0;max-width:70ch;color:#c9d3ec;position:relative}
  .flow{display:flex;flex-wrap:wrap;gap:8px;margin-top:20px;position:relative}
  .flow span{background:rgba(255,255,255,.09);border:1px solid rgba(255,255,255,.16);border-radius:8px;
    padding:6px 13px;font:600 15.3px 'Space Grotesk';backdrop-filter:blur(2px)}
  .flow i{opacity:.55;font-style:normal;align-self:center}

  .profile{display:grid;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));gap:12px;margin:16px 0 6px}
  .pcard{background:var(--pane);border:1px solid var(--line);border-radius:var(--radius);padding:14px 16px;box-shadow:var(--shadow)}
  .pcard .k{font-size:13.5px;letter-spacing:.06em;text-transform:uppercase;color:var(--ink-soft)}
  .pcard .v{font:700 24.5px/1.1 'Space Grotesk';margin-top:5px}
  .pcard .v small{font-size:14.7px;font-weight:500;color:var(--ink-soft)}
  .pcard.accent{background:linear-gradient(135deg,#111a35,#241a52);color:#fff;border:none}
  .pcard.accent .k{color:#9fb0ff}.pcard.accent .v small{color:#c9d3ec}

  .howto{background:var(--pane);border:1px solid var(--line);border-left:4px solid #6366f1;border-radius:12px;
    padding:16px 18px;margin:18px 0 6px;box-shadow:var(--shadow)}
  .howto b{color:#4f46e5}
  .howto .steps{display:flex;flex-wrap:wrap;gap:8px 18px;margin-top:8px;font-size:17.2px;color:var(--ink-soft)}

  /* ---------- Sections ---------- */
  .sec{scroll-margin-top:16px;padding-top:40px}
  .sechead{display:flex;align-items:center;gap:14px;margin-bottom:6px}
  .sechead .num{font:700 15.9px 'JetBrains Mono';color:#fff;background:var(--accent);border-radius:9px;
    width:40px;height:40px;display:grid;place-items:center;flex:0 0 auto;box-shadow:0 6px 16px -6px var(--accent)}
  .sechead h3{font:700 28.2px/1.1 'Space Grotesk';margin:0}
  .sechead .rng{margin-left:auto;font:500 14.7px 'JetBrains Mono';color:var(--ink-soft);
    background:var(--chip);border:1px solid var(--line);padding:4px 10px;border-radius:20px}
  .secsub{color:var(--ink-soft);margin:2px 0 14px;font-size:17.2px;border-left:3px solid var(--accent);padding-left:12px}
  .divider{height:3px;background:linear-gradient(90deg,var(--accent),transparent);border-radius:3px;margin:0 0 18px;opacity:.7}

  /* ---------- Q&A cards ---------- */
  details.qa{background:var(--pane);border:1px solid var(--line);border-radius:12px;margin:11px 0;
    box-shadow:var(--shadow);overflow:hidden;transition:border-color .15s}
  details.qa[open]{border-color:color-mix(in srgb,var(--accent) 45%,var(--line))}
  details.qa[data-st="ok"]{border-left:4px solid var(--ok)}
  details.qa[data-st="shaky"]{border-left:4px solid var(--shaky)}
  details.qa[data-st="blank"]{border-left:4px solid var(--blank)}
  summary.qh{list-style:none;cursor:pointer;padding:15px 16px;display:flex;gap:13px;align-items:flex-start;user-select:none}
  summary.qh::-webkit-details-marker{display:none}
  .qnum{font:700 14.7px 'JetBrains Mono';color:var(--accent);background:color-mix(in srgb,var(--accent) 12%,#fff);
    border:1px solid color-mix(in srgb,var(--accent) 30%,var(--line));border-radius:7px;padding:3px 8px;flex:0 0 auto;min-width:40px;text-align:center}
  .qtxt{flex:1;font-weight:600;font-size:18.4px;padding-top:1px}
  .qtag{font:600 12.3px 'JetBrains Mono';letter-spacing:.05em;text-transform:uppercase;padding:3px 8px;border-radius:20px;flex:0 0 auto;align-self:center}
  .tag-concept{background:#eef2ff;color:#4f46e5}
  .tag-scenario{background:#fff7ed;color:#c2410c}
  .tag-experience{background:#f0fdf4;color:#15803d}
  .tag-cmd{background:#ecfeff;color:#0e7490}
  .chev{flex:0 0 auto;align-self:center;transition:transform .2s;opacity:.5}
  details.qa[open] .chev{transform:rotate(90deg)}
  .qbody{padding:2px 18px 18px 18px;border-top:1px dashed var(--line)}
  .qbody>*:first-child{margin-top:12px}

  /* answer internals */
  .qbody p{margin:9px 0}
  .qbody ul,.qbody ol{margin:9px 0;padding-left:22px}
  .qbody li{margin:5px 0}
  .qbody strong{color:#111827}
  .lead{font-size:17.2px}
  .say{background:color-mix(in srgb,var(--accent) 7%,#fff);border:1px solid color-mix(in srgb,var(--accent) 22%,var(--line));
    border-radius:10px;padding:11px 14px;margin:13px 0;font-size:17.2px}
  .say b{color:var(--accent);font-family:'Space Grotesk';font-size:13.5px;letter-spacing:.08em;text-transform:uppercase;display:block;margin-bottom:3px}
  .mine{background:#fffdf5;border:1px dashed #e5cf8f;border-radius:10px;padding:10px 14px;margin:13px 0;font-size:16.5px}
  .mine b{color:#a16207}
  .note{font-size:15.9px;color:var(--ink-soft);border-left:3px solid var(--line);padding-left:11px;margin:11px 0}

  /* code */
  pre{background:var(--code-bg);color:var(--code-ink);border-radius:11px;padding:14px 15px;overflow-x:auto;
    margin:13px 0;font-size:15.9px;line-height:1.55;position:relative;border:1px solid #1c2842;border-left:3px solid var(--accent)}
  pre code{color:inherit;white-space:pre}
  pre .lang{position:absolute;top:0;right:0;font-size:11.6px;letter-spacing:.1em;text-transform:uppercase;
    color:#8ea0c6;background:#1a2440;padding:3px 9px;border-radius:0 10px 0 8px}
  .c-cmt{color:#6b7b9e}.c-key{color:#7dd3fc}.c-str{color:#86efac}.c-num{color:#fbbf24}.c-fn{color:#f0abfc}.c-op{color:#fca5a5}
  code.inl{background:var(--chip);border:1px solid var(--line);border-radius:5px;padding:.5px 6px;font-size:15.3px;color:#b83280}

  /* tables */
  .tbl{width:100%;border-collapse:collapse;margin:13px 0;font-size:16.5px;overflow:hidden;border-radius:10px;
    box-shadow:0 0 0 1px var(--line)}
  .tbl th{background:var(--accent);color:#fff;text-align:left;padding:9px 12px;font:600 15.3px 'Space Grotesk';letter-spacing:.02em}
  .tbl td{padding:9px 12px;border-top:1px solid var(--line);vertical-align:top}
  .tbl tr:nth-child(even) td{background:#fafbfe}
  .tbl td:first-child{font-weight:600;color:#1f2733;white-space:nowrap}

  /* diagrams */
  .dia{background:#fbfcfe;border:1px solid var(--line);border-radius:12px;padding:14px;margin:14px 0;overflow-x:auto}
  .dia svg{display:block;margin:0 auto;max-width:100%;height:auto}
  .diacap{font-size:14.7px;color:var(--ink-soft);text-align:center;margin-top:8px;font-style:italic}

  /* progress buttons */
  .prog{display:flex;gap:6px;padding:0 16px 14px 16px;align-items:center}
  .prog .lab{font-size:13.5px;color:var(--ink-soft);margin-right:2px}
  .prog button{border:1px solid var(--line);background:#fff;border-radius:8px;padding:4px 11px;font-size:14.7px;
    font-weight:600;cursor:pointer;color:var(--ink-soft);transition:.12s}
  .prog button:hover{border-color:#b9c2d4}
  .prog button.on-ok{background:var(--ok);border-color:var(--ok);color:#fff}
  .prog button.on-sh{background:var(--shaky);border-color:var(--shaky);color:#fff}
  .prog button.on-bl{background:var(--blank);border-color:var(--blank);color:#fff}

  .callout{background:linear-gradient(120deg,#0f1830,#1a1442);color:#dbe4f5;border-radius:14px;padding:18px 22px;margin:26px 0}
  .callout h4{margin:0 0 6px;font:700 19.6px 'Space Grotesk';color:#fff}
  .callout p{margin:0;color:#b9c4e0;font-size:17.2px}

  .foot{margin-top:60px;padding-top:22px;border-top:1px solid var(--line);font-size:15.3px;color:var(--ink-soft)}
  .foot b{color:var(--ink)}

  .no-results{display:none;text-align:center;padding:50px;color:var(--ink-soft)}

  /* mobile */
  .menutoggle{display:none}
  @media(max-width:900px){
    .wrap{grid-template-columns:1fr}
    .rail{position:static;height:auto;border-right:none;border-bottom:1px solid #0a0f1c}
    .main{padding-bottom:80px}
    .menutoggle{display:block}
    #nav.collapsed,#legendbox.collapsed{display:none}
    .hero h2{font-size:29.4px}
  }
  @media print{
    .rail,.prog,.chev{display:none}.wrap{display:block}details.qa{break-inside:avoid}
    details.qa[open]{border:1px solid #ccc}.qbody{border-top:1px solid #eee}
  }
  :focus-visible{outline:3px solid #6366f1;outline-offset:2px;border-radius:4px}
  @media(prefers-reduced-motion:reduce){*{transition:none!important;scroll-behavior:auto!important}}


  /* ---- extensions for the Approaches playbook ---- */
  /* fit content to the full viewport width (reference hard-capped .main at 1120px) */
  .main{max-width:none}
  @media(min-width:1700px){.main{padding-right:clamp(40px,5vw,120px)}}
  .sublabel{font:600 14.7px 'Space Grotesk';letter-spacing:.02em;color:var(--accent);margin:15px 0 2px;
    text-transform:none}
  .qbody .sublabel:first-child{margin-top:6px}
  ul.fu li{color:var(--ink-soft)} ul.fu li em{color:var(--ink);font-style:normal;font-weight:600}
  .essentials{background:linear-gradient(135deg,#0f1830,#1a1442);color:#dbe4f5;border-radius:14px;
    padding:18px 22px;margin:14px 0 18px;box-shadow:var(--shadow)}
  .essentials.closing{background:linear-gradient(135deg,#101a30,#241a52)}
  .essentials .ess-h{font:700 18.4px 'Space Grotesk';color:#fff;margin-bottom:10px}
  .essentials p{margin:8px 0;color:#c4d0ea;font-size:17.2px}
  .essentials strong{color:#fff}
  .essentials ul,.essentials ol{margin:8px 0;padding-left:20px;color:#c4d0ea;font-size:17.2px}
  .essentials li{margin:4px 0}
  .essentials code.inl{background:#0b1224;border-color:#26355a;color:#93c5fd}
  .essentials pre{background:#0a1020;border-left-color:#6366f1}
  .essentials .tbl th{background:#26325a}.essentials .tbl td{background:#0f1830!important;border-color:#22304f;color:#c4d0ea}
  details.inv{background:var(--pane);border:1px solid var(--line);border-radius:12px;margin:0 0 16px;box-shadow:var(--shadow)}
  details.inv summary{cursor:pointer;padding:12px 16px;font:600 16.5px 'Space Grotesk';color:var(--ink);list-style:none}
  details.inv summary::-webkit-details-marker{display:none}
  details.inv .invbody{padding:2px 18px 16px;border-top:1px dashed var(--line);font-size:16.5px;color:var(--ink-soft)}
  details.inv .invbody strong{color:var(--ink)}
  /* copy button on code */
  pre .copy{position:absolute;top:4px;right:64px;font:600 11.6px 'JetBrains Mono';letter-spacing:.08em;
    text-transform:uppercase;color:#8ea0c6;background:#1a2440;border:none;padding:3px 8px;border-radius:6px;
    cursor:pointer;opacity:0;transition:.15s}
  pre:hover .copy{opacity:1} pre .copy:hover{color:#fff;background:#26325a} pre .copy.done{color:#86efac}
  /* animated diagram flows */
  .dia .flow-line{stroke-dasharray:6 5;animation:dash 1.2s linear infinite}
  @keyframes dash{to{stroke-dashoffset:-22}}
  @media(prefers-reduced-motion:reduce){.dia .flow-line{animation:none}}
  .dia:hover .hl{filter:brightness(1.05)}
  /* filter active state on legend rows */
  .legend .row.filter{cursor:pointer;border-radius:7px;padding:5px 6px;margin:2px -6px;transition:.12s}
  .legend .row.filter:hover{background:#16203a}
  .legend .row.filter.active{background:#1c2743;box-shadow:inset 0 0 0 1px #2c3e6b}


/* ============================================================
   Multi-page additions (course-playbook)
   ============================================================ */
.nav a.here{background:#1c2743;color:#fff}
.nav a.here .dot{box-shadow:0 0 0 3px rgba(255,255,255,.12)}
.nav a.soon{opacity:.5;pointer-events:none}
.nav a .soonbadge{font-size:10.5px;letter-spacing:.05em;text-transform:uppercase;color:#5b6a8a;
  border:1px solid #26355a;border-radius:20px;padding:0 6px;margin-left:auto}
.nav a .tick{margin-left:auto;color:#4ade80;font-size:13px}

.crumb{display:flex;align-items:center;gap:8px;flex-wrap:wrap;margin:26px 0 0;font-size:14.7px;color:var(--ink-soft)}
.crumb a{color:var(--accent,#6366f1);text-decoration:none;font-weight:600}
.crumb a:hover{text-decoration:underline}
.crumb .sep{opacity:.5}

.srcvids{display:flex;flex-wrap:wrap;gap:7px;margin:14px 0 2px}
.srcvids .v{background:var(--chip);border:1px solid var(--line);border-radius:20px;padding:4px 11px;
  font:600 13.5px 'JetBrains Mono';color:var(--ink-soft)}
.srcvids .v b{color:var(--ink)}

.lesson{scroll-margin-top:16px;padding-top:30px}
.lessonhead{display:flex;align-items:center;gap:12px;margin:6px 0 4px}
.lessonhead .lnum{font:700 13.5px 'JetBrains Mono';color:#fff;background:var(--accent,#6366f1);border-radius:8px;
  padding:4px 9px;flex:0 0 auto}
.lessonhead h4{font:700 22px/1.15 'Space Grotesk';margin:0}
.lessonsub{color:var(--ink-soft);font-size:16.5px;margin:2px 0 8px}

.drillband{background:linear-gradient(120deg,#0f1830,#1a1442);color:#dbe4f5;border-radius:16px;
  padding:22px 26px;margin:40px 0 8px;box-shadow:var(--shadow)}
.drillband .eyebrow{font:600 13px/1 'Space Grotesk';letter-spacing:.2em;text-transform:uppercase;color:#9fb0ff}
.drillband h3{font:700 27px/1.1 'Space Grotesk';margin:10px 0 6px;color:#fff}
.drillband p{margin:0;color:#c4d0ea;font-size:16.8px;max-width:75ch}

.chapters{display:grid;grid-template-columns:repeat(auto-fill,minmax(268px,1fr));gap:14px;margin:12px 0 8px}
.chcard{display:block;text-decoration:none;color:inherit;background:var(--pane);border:1px solid var(--line);
  border-left:4px solid var(--c,#6366f1);border-radius:14px;padding:15px 17px;box-shadow:var(--shadow);
  transition:transform .13s,box-shadow .13s,border-color .13s}
.chcard:hover{transform:translateY(-2px);box-shadow:0 10px 30px -10px rgba(16,24,40,.18)}
.chcard.soon{opacity:.62}
.chcard.soon:hover{transform:none}
.chcard .chtop{display:flex;align-items:center;gap:10px;margin-bottom:7px}
.chcard .chico{font-size:22px;line-height:1}
.chcard .chday{font:600 12px 'JetBrains Mono';color:var(--ink-soft);background:var(--chip);
  border:1px solid var(--line);border-radius:20px;padding:2px 8px;margin-left:auto}
.chcard h3{font:700 19px/1.15 'Space Grotesk';margin:0 0 4px}
.chcard p{margin:0;font-size:14.7px;color:var(--ink-soft);line-height:1.5}
.chcard .chmeta{margin-top:10px;display:flex;gap:8px;flex-wrap:wrap;font:600 12px 'JetBrains Mono';color:var(--ink-soft)}
.chcard .chmeta span{background:var(--chip);border:1px solid var(--line);border-radius:6px;padding:2px 7px}
.chcard .chmeta .pb{color:#c2410c;background:#fff7ed;border-color:#fed7aa}
.grouptitle{font:700 15px 'Space Grotesk';letter-spacing:.14em;text-transform:uppercase;color:var(--ink-soft);
  margin:30px 0 4px}
.grouprule{height:3px;background:linear-gradient(90deg,#6366f1,transparent);border-radius:3px;margin:0 0 14px;opacity:.5}

/* ---- on-this-page TOC (chapter jump nav) ---- */
.toc{background:var(--pane);border:1px solid var(--line);border-radius:12px;padding:13px 16px;margin:16px 0 4px;box-shadow:var(--shadow)}
.toc .toch{font:600 12.5px 'Space Grotesk';letter-spacing:.12em;text-transform:uppercase;color:var(--ink-soft);margin-bottom:9px}
.toc ol{margin:0;padding:0;list-style:none;display:grid;grid-template-columns:repeat(auto-fill,minmax(230px,1fr));gap:4px 16px;counter-reset:t}
.toc li{counter-increment:t}
.toc a{display:flex;gap:8px;align-items:baseline;text-decoration:none;color:var(--ink-soft);font-size:15.3px;padding:3px 0;border-radius:6px}
.toc a:before{content:counter(t,decimal-leading-zero);font:700 12px 'JetBrains Mono';color:var(--accent,#6366f1);flex:0 0 auto}
.toc a:hover{color:var(--accent,#6366f1)}
.toc a b{color:var(--ink);font-weight:600}

/* ============================================================
   Phase banners (Theory / Lab / Interview) + interview cards
   ============================================================ */
.phase{position:relative;overflow:hidden;border-radius:18px;padding:22px 26px;margin:46px 0 10px;color:#fff;
  display:flex;align-items:center;gap:20px;box-shadow:var(--shadow)}
.phase:after{content:"";position:absolute;inset:0;opacity:.5;
  background:linear-gradient(90deg,transparent,transparent 96%,rgba(255,255,255,.05)),
  linear-gradient(0deg,transparent,transparent 96%,rgba(255,255,255,.05));background-size:22px 22px}
.phase .pbig{font:700 46px/1 'Space Grotesk';opacity:.9;position:relative;flex:0 0 auto;width:64px;text-align:center}
.phase .pmeta{position:relative}
.phase .pk{font:600 12.5px/1 'Space Grotesk';letter-spacing:.24em;text-transform:uppercase;opacity:.82}
.phase h3{font:700 28px/1.08 'Space Grotesk';margin:8px 0 5px}
.phase p{margin:0;font-size:16.5px;opacity:.92;max-width:80ch}
.phase.theory{background:radial-gradient(900px 240px at 0% -30%,#3b3f8f 0%,transparent 60%),linear-gradient(120deg,#111a35,#241a52)}
.phase.lab{background:radial-gradient(900px 240px at 0% -30%,#0f6b4f 0%,transparent 60%),linear-gradient(120deg,#07231d,#0c3b2c)}
.phase.interview{background:radial-gradient(900px 240px at 0% -30%,#0e7490 0%,transparent 60%),linear-gradient(120deg,#0a2230,#0e3a4a)}
.phase.drills{background:radial-gradient(900px 240px at 0% -30%,#7a2a1f 0%,transparent 60%),linear-gradient(120deg,#2a140f,#3a1a12)}

details.iq{background:var(--pane);border:1px solid var(--line);border-left:4px solid #0e7490;border-radius:11px;
  margin:10px 0;box-shadow:var(--shadow);overflow:hidden;transition:border-color .15s}
details.iq[open]{border-left-color:#06b6d4;border-color:#a5e4ef}
details.iq summary{list-style:none;cursor:pointer;padding:14px 16px;display:flex;gap:12px;align-items:flex-start;user-select:none}
details.iq summary::-webkit-details-marker{display:none}
details.iq .qq{font:700 13px 'JetBrains Mono';color:#0e7490;background:#ecfeff;border:1px solid #a5e4ef;
  border-radius:7px;padding:3px 9px;flex:0 0 auto}
details.iq .qtext{flex:1;font-weight:600;font-size:17.5px;padding-top:2px}
details.iq .rev{flex:0 0 auto;align-self:center;font:600 12px 'JetBrains Mono';letter-spacing:.06em;text-transform:uppercase;
  color:#0e7490;opacity:.7}
details.iq[open] .rev{opacity:0}
details.iq .ans{padding:4px 18px 17px 18px;border-top:1px dashed var(--line);font-size:16.6px}
details.iq .ans:first-child{margin-top:10px}
details.iq .ans .alab{display:inline-block;font:700 11.5px 'Space Grotesk';letter-spacing:.1em;text-transform:uppercase;
  color:#0e7490;background:#ecfeff;border:1px solid #a5e4ef;border-radius:6px;padding:2px 8px;margin:10px 0 4px}
details.iq .ans p{margin:8px 0}
details.iq .ans code.inl{color:#0e7490}

.fig{background:linear-gradient(160deg,#fbfcfe,#f2f5fb);border:1px solid var(--line);border-radius:14px;
  padding:18px 18px 12px;margin:16px 0;overflow-x:auto;box-shadow:var(--shadow)}
.fig svg{display:block;margin:0 auto;max-width:100%;height:auto}
.fig .figcap{font-size:14.7px;color:var(--ink-soft);text-align:center;margin-top:10px}
.fig .figcap b{color:var(--ink)}
.fig.dark{background:linear-gradient(160deg,#0f1830,#1a1442)}
.fig.dark .figcap{color:#9fb0ff}.fig.dark .figcap b{color:#eaf0fb}

.legchips{display:flex;flex-wrap:wrap;gap:8px 14px;justify-content:center;margin-top:6px;font-size:13.5px;color:var(--ink-soft)}
.legchips span{display:inline-flex;align-items:center;gap:6px}
.legchips i{width:12px;height:12px;border-radius:3px;display:inline-block}

.fig .flow-line{stroke-dasharray:6 5;animation:dash 1.1s linear infinite}
@media(prefers-reduced-motion:reduce){.fig .flow-line{animation:none}}

/* ============================================================
   Multi-page additions (course-playbook)
   ============================================================ */
.nav a.here{background:#1c2743;color:#fff}
.nav a.here .dot{box-shadow:0 0 0 3px rgba(255,255,255,.12)}
.nav a.soon{opacity:.5;pointer-events:none}
.nav a .soonbadge{font-size:10.5px;letter-spacing:.05em;text-transform:uppercase;color:#5b6a8a;
  border:1px solid #26355a;border-radius:20px;padding:0 6px;margin-left:auto}
.nav a .tick{margin-left:auto;color:#4ade80;font-size:13px}

.crumb{display:flex;align-items:center;gap:8px;flex-wrap:wrap;margin:26px 0 0;font-size:14.7px;color:var(--ink-soft)}
.crumb a{color:var(--accent,#6366f1);text-decoration:none;font-weight:600}
.crumb a:hover{text-decoration:underline}
.crumb .sep{opacity:.5}

.srcvids{display:flex;flex-wrap:wrap;gap:7px;margin:14px 0 2px}
.srcvids .v{background:var(--chip);border:1px solid var(--line);border-radius:20px;padding:4px 11px;
  font:600 13.5px 'JetBrains Mono';color:var(--ink-soft)}
.srcvids .v b{color:var(--ink)}

.lesson{scroll-margin-top:16px;padding-top:30px}
.lessonhead{display:flex;align-items:center;gap:12px;margin:6px 0 4px}
.lessonhead .lnum{font:700 13.5px 'JetBrains Mono';color:#fff;background:var(--accent,#6366f1);border-radius:8px;
  padding:4px 9px;flex:0 0 auto}
.lessonhead h4{font:700 22px/1.15 'Space Grotesk';margin:0}
.lessonsub{color:var(--ink-soft);font-size:16.5px;margin:2px 0 8px}

.drillband{background:linear-gradient(120deg,#0f1830,#1a1442);color:#dbe4f5;border-radius:16px;
  padding:22px 26px;margin:40px 0 8px;box-shadow:var(--shadow)}
.drillband .eyebrow{font:600 13px/1 'Space Grotesk';letter-spacing:.2em;text-transform:uppercase;color:#9fb0ff}
.drillband h3{font:700 27px/1.1 'Space Grotesk';margin:10px 0 6px;color:#fff}
.drillband p{margin:0;color:#c4d0ea;font-size:16.8px;max-width:75ch}

.chapters{display:grid;grid-template-columns:repeat(auto-fill,minmax(268px,1fr));gap:14px;margin:12px 0 8px}
.chcard{display:block;text-decoration:none;color:inherit;background:var(--pane);border:1px solid var(--line);
  border-left:4px solid var(--c,#6366f1);border-radius:14px;padding:15px 17px;box-shadow:var(--shadow);
  transition:transform .13s,box-shadow .13s,border-color .13s}
.chcard:hover{transform:translateY(-2px);box-shadow:0 10px 30px -10px rgba(16,24,40,.18)}
.chcard.soon{opacity:.62}
.chcard.soon:hover{transform:none}
.chcard .chtop{display:flex;align-items:center;gap:10px;margin-bottom:7px}
.chcard .chico{font-size:22px;line-height:1}
.chcard .chday{font:600 12px 'JetBrains Mono';color:var(--ink-soft);background:var(--chip);
  border:1px solid var(--line);border-radius:20px;padding:2px 8px;margin-left:auto}
.chcard h3{font:700 19px/1.15 'Space Grotesk';margin:0 0 4px}
.chcard p{margin:0;font-size:14.7px;color:var(--ink-soft);line-height:1.5}
.chcard .chmeta{margin-top:10px;display:flex;gap:8px;flex-wrap:wrap;font:600 12px 'JetBrains Mono';color:var(--ink-soft)}
.chcard .chmeta span{background:var(--chip);border:1px solid var(--line);border-radius:6px;padding:2px 7px}
.chcard .chmeta .pb{color:#c2410c;background:#fff7ed;border-color:#fed7aa}
.grouptitle{font:700 15px 'Space Grotesk';letter-spacing:.14em;text-transform:uppercase;color:var(--ink-soft);
  margin:30px 0 4px}
.grouprule{height:3px;background:linear-gradient(90deg,#6366f1,transparent);border-radius:3px;margin:0 0 14px;opacity:.5}

/* ---- on-this-page TOC (chapter jump nav) ---- */
.toc{background:var(--pane);border:1px solid var(--line);border-radius:12px;padding:13px 16px;margin:16px 0 4px;box-shadow:var(--shadow)}
.toc .toch{font:600 12.5px 'Space Grotesk';letter-spacing:.12em;text-transform:uppercase;color:var(--ink-soft);margin-bottom:9px}
.toc ol{margin:0;padding:0;list-style:none;display:grid;grid-template-columns:repeat(auto-fill,minmax(230px,1fr));gap:4px 16px;counter-reset:t}
.toc li{counter-increment:t}
.toc a{display:flex;gap:8px;align-items:baseline;text-decoration:none;color:var(--ink-soft);font-size:15.3px;padding:3px 0;border-radius:6px}
.toc a:before{content:counter(t,decimal-leading-zero);font:700 12px 'JetBrains Mono';color:var(--accent,#6366f1);flex:0 0 auto}
.toc a:hover{color:var(--accent,#6366f1)}
.toc a b{color:var(--ink);font-weight:600}

/* ============================================================
   Phase banners (Theory / Lab / Interview) + interview cards
   ============================================================ */
.phase{position:relative;overflow:hidden;border-radius:18px;padding:22px 26px;margin:46px 0 10px;color:#fff;
  display:flex;align-items:center;gap:20px;box-shadow:var(--shadow)}
.phase:after{content:"";position:absolute;inset:0;opacity:.5;
  background:linear-gradient(90deg,transparent,transparent 96%,rgba(255,255,255,.05)),
  linear-gradient(0deg,transparent,transparent 96%,rgba(255,255,255,.05));background-size:22px 22px}
.phase .pbig{font:700 46px/1 'Space Grotesk';opacity:.9;position:relative;flex:0 0 auto;width:64px;text-align:center}
.phase .pmeta{position:relative}
.phase .pk{font:600 12.5px/1 'Space Grotesk';letter-spacing:.24em;text-transform:uppercase;opacity:.82}
.phase h3{font:700 28px/1.08 'Space Grotesk';margin:8px 0 5px}
.phase p{margin:0;font-size:16.5px;opacity:.92;max-width:80ch}
.phase.theory{background:radial-gradient(900px 240px at 0% -30%,#3b3f8f 0%,transparent 60%),linear-gradient(120deg,#111a35,#241a52)}
.phase.lab{background:radial-gradient(900px 240px at 0% -30%,#0f6b4f 0%,transparent 60%),linear-gradient(120deg,#07231d,#0c3b2c)}
.phase.interview{background:radial-gradient(900px 240px at 0% -30%,#0e7490 0%,transparent 60%),linear-gradient(120deg,#0a2230,#0e3a4a)}
.phase.drills{background:radial-gradient(900px 240px at 0% -30%,#7a2a1f 0%,transparent 60%),linear-gradient(120deg,#2a140f,#3a1a12)}

details.iq{background:var(--pane);border:1px solid var(--line);border-left:4px solid #0e7490;border-radius:11px;
  margin:10px 0;box-shadow:var(--shadow);overflow:hidden;transition:border-color .15s}
details.iq[open]{border-left-color:#06b6d4;border-color:#a5e4ef}
details.iq summary{list-style:none;cursor:pointer;padding:14px 16px;display:flex;gap:12px;align-items:flex-start;user-select:none}
details.iq summary::-webkit-details-marker{display:none}
details.iq .qq{font:700 13px 'JetBrains Mono';color:#0e7490;background:#ecfeff;border:1px solid #a5e4ef;
  border-radius:7px;padding:3px 9px;flex:0 0 auto}
details.iq .qtext{flex:1;font-weight:600;font-size:17.5px;padding-top:2px}
details.iq .rev{flex:0 0 auto;align-self:center;font:600 12px 'JetBrains Mono';letter-spacing:.06em;text-transform:uppercase;
  color:#0e7490;opacity:.7}
details.iq[open] .rev{opacity:0}
details.iq .ans{padding:4px 18px 17px 18px;border-top:1px dashed var(--line);font-size:16.6px}
details.iq .ans:first-child{margin-top:10px}
details.iq .ans .alab{display:inline-block;font:700 11.5px 'Space Grotesk';letter-spacing:.1em;text-transform:uppercase;
  color:#0e7490;background:#ecfeff;border:1px solid #a5e4ef;border-radius:6px;padding:2px 8px;margin:10px 0 4px}
details.iq .ans p{margin:8px 0}
details.iq .ans code.inl{color:#0e7490}

.fig{background:linear-gradient(160deg,#fbfcfe,#f2f5fb);border:1px solid var(--line);border-radius:14px;
  padding:18px 18px 12px;margin:16px 0;overflow-x:auto;box-shadow:var(--shadow)}
.fig svg{display:block;margin:0 auto;max-width:100%;height:auto}
.fig .figcap{font-size:14.7px;color:var(--ink-soft);text-align:center;margin-top:10px}
.fig .figcap b{color:var(--ink)}
.fig.dark{background:linear-gradient(160deg,#0f1830,#1a1442)}
.fig.dark .figcap{color:#9fb0ff}.fig.dark .figcap b{color:#eaf0fb}

.legchips{display:flex;flex-wrap:wrap;gap:8px 14px;justify-content:center;margin-top:6px;font-size:13.5px;color:var(--ink-soft)}
.legchips span{display:inline-flex;align-items:center;gap:6px}
.legchips i{width:12px;height:12px;border-radius:3px;display:inline-block}

.fig .flow-line{stroke-dasharray:6 5;animation:dash 1.1s linear infinite}
@media(prefers-reduced-motion:reduce){.fig .flow-line{animation:none}}