/* Hook Chain — shared styles (sister of Decision Tier). Light is the default; dark follows the OS unless the
   reader picks a theme with the toggle (stored as data-theme on <html>). */
:root {
  --bg: #f8f5ef;
  --bg-raised: #ffffff;
  --bg-sunk: #efe9df;
  --ink: #221a33;
  --ink-soft: #463d59;
  --ink-faint: #6f6880;
  --line: #e0d7ca;
  --teal: #5b3f8f;
  --teal-soft: #e8e0f3;
  --coral: #c0582f;
  --coral-soft: #f6e0d4;
  --amber: #b9861c;
  --amber-soft: #f5ead1;
  --navy-soft: #dfe8df;
  --code-bg: #f0eadf;
  --shadow: 0 1px 2px rgba(20, 33, 61, .06), 0 6px 24px rgba(20, 33, 61, .06);
  --radius: 14px;
  --serif: "Fraunces", Georgia, serif;
  --sans: "Inter", system-ui, -apple-system, "Segoe UI", sans-serif;
  --mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, monospace;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #15111f; --bg-raised: #1e182c; --bg-sunk: #0f0c17; --ink: #f1ebe0; --ink-soft: #cdc6d8;
    --ink-faint: #958ea6; --line: #322a44; --teal: #b39ce6; --teal-soft: #2c2342; --coral: #ee8f66;
    --coral-soft: #3b2118; --amber: #eab65a; --amber-soft: #3a2c12; --navy-soft: #1f2d24; --code-bg: #0f0c17;
    --shadow: 0 1px 2px rgba(0,0,0,.3), 0 8px 28px rgba(0,0,0,.25); color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #15111f; --bg-raised: #1e182c; --bg-sunk: #0f0c17; --ink: #f1ebe0; --ink-soft: #cdc6d8;
    --ink-faint: #958ea6; --line: #322a44; --teal: #b39ce6; --teal-soft: #2c2342; --coral: #ee8f66;
    --coral-soft: #3b2118; --amber: #eab65a; --amber-soft: #3a2c12; --navy-soft: #1f2d24; --code-bg: #0f0c17;
  --shadow: 0 1px 2px rgba(0,0,0,.3), 0 8px 28px rgba(0,0,0,.25); color-scheme: dark;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body { margin: 0; background: var(--bg); color: var(--ink); font: 17px/1.65 var(--sans); }
img { max-width: 100%; height: auto; }
a { color: var(--teal); text-underline-offset: 3px; }
a:hover { color: var(--coral); }
:focus-visible { outline: 3px solid var(--amber); outline-offset: 2px; border-radius: 4px; }
.skip { position: absolute; left: -999px; top: 8px; background: var(--ink); color: var(--bg); padding: 8px 12px; z-index: 10; }
.skip:focus { left: 8px; }

/* Top bar */
.topbar { position: sticky; top: 0; z-index: 5; display: flex; align-items: center; justify-content: space-between;
  padding: 10px 20px; background: color-mix(in srgb, var(--bg) 88%, transparent); backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line); }
.brand { display: flex; align-items: center; gap: 10px; text-decoration: none; color: var(--ink); font: 700 19px var(--serif); }
.topbar-actions { display: flex; gap: 8px; }
.topbar button { font: 600 14px var(--sans); color: var(--ink); background: var(--bg-raised); border: 1px solid var(--line);
  border-radius: 999px; padding: 6px 12px; cursor: pointer; }
.menu-toggle { display: none; }

/* Layout */
.layout { display: grid; grid-template-columns: 250px minmax(0, 1fr); max-width: 1240px; margin: 0 auto; }
.sidenav { position: sticky; top: 57px; align-self: start; height: calc(100vh - 57px); overflow-y: auto; padding: 24px 16px 40px 20px;
  border-right: 1px solid var(--line); font-size: 15px; }
.nav-start { display: block; font-weight: 700; text-decoration: none; color: var(--ink); margin-bottom: 14px; }
.nav-head { margin: 18px 0 6px; font-size: 11.5px; font-weight: 700; letter-spacing: .09em; text-transform: uppercase; color: var(--ink-faint); }
.sidenav ul { list-style: none; margin: 0; padding: 0; }
.sidenav li a { display: block; padding: 5px 10px; margin: 1px 0; border-radius: 8px; text-decoration: none; color: var(--ink-soft); }
.sidenav li a:hover { background: var(--bg-sunk); color: var(--ink); }
.sidenav li a[aria-current="page"] { background: var(--teal-soft); color: var(--ink); font-weight: 600; }
.nav-foot { margin-top: 28px; font-size: 14px; }
.content { min-width: 0; padding: 36px 48px 40px; max-width: 900px; }
body.home .content { max-width: 980px; }

/* Typography */
h1, h2, h3, h4 { font-family: var(--serif); line-height: 1.2; color: var(--ink); letter-spacing: -.01em; }
h1 { font-size: clamp(32px, 5vw, 46px); margin: 8px 0 14px; }
h2 { font-size: clamp(24px, 3.4vw, 30px); margin: 48px 0 12px; padding-top: 8px; }
h3 { font-size: 21px; margin: 30px 0 8px; }
h4 { font-size: 17px; margin: 22px 0 6px; font-family: var(--sans); font-weight: 700; }
p, li { color: var(--ink-soft); }
strong { color: var(--ink); }
.lede { font-size: 20px; line-height: 1.55; color: var(--ink-soft); max-width: 46em; }
.eyebrow { display: inline-flex; gap: 8px; align-items: center; font-size: 12.5px; font-weight: 700; letter-spacing: .09em;
  text-transform: uppercase; color: var(--ink-faint); }
code, kbd { font-family: var(--mono); font-size: .88em; background: var(--code-bg); padding: .1em .35em; border-radius: 5px; }
pre { background: var(--code-bg); border: 1px solid var(--line); border-radius: 10px; padding: 14px 16px; overflow-x: auto;
  font: 14px/1.55 var(--mono); }
pre code { background: none; padding: 0; font-size: inherit; }
hr { border: 0; border-top: 1px solid var(--line); margin: 40px 0; }
blockquote { margin: 20px 0; padding: 4px 20px; border-left: 4px solid var(--amber); background: var(--amber-soft); border-radius: 0 10px 10px 0; }
blockquote p { color: var(--ink); }

/* Level badges */
.badge { display: inline-block; font: 700 11.5px/1 var(--sans); letter-spacing: .06em; padding: 5px 8px; border-radius: 999px; text-transform: uppercase; }
.badge.l0 { background: var(--amber-soft); color: var(--amber); }
.badge.l1 { background: var(--teal-soft); color: var(--teal); }
.badge.l2 { background: var(--navy-soft); color: var(--ink); }
.badge.l3 { background: var(--coral-soft); color: var(--coral); }
.badge.arch, .badge.data, .badge.build { background: var(--bg-sunk); color: var(--ink-soft); border: 1px solid var(--line); }

/* Figures */
figure { margin: 26px 0; }
figure img { display: block; border-radius: var(--radius); border: 1px solid var(--line); box-shadow: var(--shadow); }
figcaption { font-size: 14px; color: var(--ink-faint); margin-top: 8px; }
.hero-img { width: 100%; }

/* Tables */
.table-wrap { overflow-x: auto; margin: 18px 0 22px; border: 1px solid var(--line); border-radius: 12px; background: var(--bg-raised); }
table { width: 100%; border-collapse: collapse; font-size: 15px; }
th, td { text-align: left; padding: 9px 12px; border-bottom: 1px solid var(--line); vertical-align: top; color: var(--ink-soft); }
th { font-weight: 700; color: var(--ink); background: var(--bg-sunk); font-size: 13.5px; }
tr:last-child td { border-bottom: 0; }
td.num, th.num { text-align: right; font-variant-numeric: tabular-nums; white-space: nowrap; }
td.best { color: var(--ink); font-weight: 700; }

/* Cards and callouts */
.cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(230px, 1fr)); gap: 16px; margin: 20px 0; }
.card { display: block; background: var(--bg-raised); border: 1px solid var(--line); border-radius: var(--radius); padding: 18px 18px 16px;
  box-shadow: var(--shadow); text-decoration: none; color: inherit; transition: transform .15s ease, border-color .15s ease; }
a.card:hover { transform: translateY(-2px); border-color: var(--teal); color: inherit; }
.card h3 { margin: 10px 0 6px; font-size: 19px; }
.card p { margin: 0; font-size: 15px; }
.callout { border: 1px solid var(--line); border-left: 5px solid var(--teal); background: var(--bg-raised); border-radius: 10px; padding: 12px 18px; margin: 20px 0; }
.callout.warn { border-left-color: var(--coral); }
.callout.note { border-left-color: var(--amber); }
.callout p:first-child { margin-top: 4px; }
.callout p:last-child { margin-bottom: 4px; }
.kicker { font-weight: 700; color: var(--ink); }
.big-rule { font: 600 22px/1.4 var(--serif); color: var(--ink); border-top: 2px solid var(--ink); border-bottom: 2px solid var(--ink); padding: 16px 0; margin: 30px 0; }
.two-col { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.steps { counter-reset: step; list-style: none; padding: 0; }
.steps > li { counter-increment: step; position: relative; padding-left: 44px; margin: 14px 0; }
.steps > li::before { content: counter(step); position: absolute; left: 0; top: 0; width: 30px; height: 30px; border-radius: 50%;
  background: var(--teal); color: var(--bg); font: 700 14px/30px var(--sans); text-align: center; }

/* Home */
.home-hero { margin: 0 0 10px; }
.ladder { display: grid; gap: 12px; margin: 24px 0; }
.rung { display: grid; grid-template-columns: 74px 1fr; gap: 16px; align-items: center; background: var(--bg-raised); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 14px 18px; text-decoration: none; color: inherit; box-shadow: var(--shadow); }
a.rung:hover { border-color: var(--teal); color: inherit; }
.rung .lvl { font: 700 28px var(--serif); color: var(--teal); text-align: center; }
.rung h3 { margin: 0 0 2px; font-size: 19px; }
.rung p { margin: 0; font-size: 15px; }

/* Interactive widgets */
.widget { background: var(--bg-raised); border: 1px solid var(--line); border-radius: var(--radius); padding: 18px 20px; margin: 24px 0; box-shadow: var(--shadow); }
.widget h4 { margin-top: 0; }
.widget label { display: grid; grid-template-columns: 150px 1fr 64px; gap: 12px; align-items: center; font-size: 15px; color: var(--ink-soft); margin: 8px 0; }
.widget input[type=range] { width: 100%; accent-color: var(--teal); }
.widget input[type=number] { width: 100%; font: 15px var(--sans); padding: 6px 8px; border: 1px solid var(--line); border-radius: 8px; background: var(--bg); color: var(--ink); }
.widget output, .widget .val { font-variant-numeric: tabular-nums; font-weight: 700; color: var(--ink); text-align: right; }
.readout { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 14px; }
.stat { flex: 1 1 140px; background: var(--bg-sunk); border-radius: 10px; padding: 10px 14px; }
.stat .k { font-size: 12px; font-weight: 700; letter-spacing: .07em; text-transform: uppercase; color: var(--ink-faint); }
.stat .v { font: 700 24px var(--serif); color: var(--ink); font-variant-numeric: tabular-nums; }
.verdict { margin-top: 12px; padding: 10px 14px; border-radius: 10px; font-weight: 600; }
.verdict.act { background: var(--teal-soft); color: var(--ink); }
.verdict.watch { background: var(--amber-soft); color: var(--ink); }
.verdict.up { background: var(--coral-soft); color: var(--ink); }
.bars { display: flex; gap: 14px; align-items: flex-end; height: 140px; margin: 14px 0 4px; padding: 0 6px; border-bottom: 1px solid var(--line); }
.bars div { flex: 1; background: var(--ink-faint); opacity: .45; border-radius: 6px 6px 0 0; position: relative; transition: height .15s ease; }
.bars div.win { background: var(--coral); opacity: 1; }
.bars div span { position: absolute; top: -22px; left: 0; right: 0; text-align: center; font-size: 13px; font-weight: 700; color: var(--ink); }
.bar-labels { display: flex; gap: 14px; padding: 0 6px; font-size: 13px; color: var(--ink-faint); }
.bar-labels span { flex: 1; text-align: center; }

/* Cost ladder chart */
.cost-row { display: grid; grid-template-columns: 170px 1fr 92px; gap: 12px; align-items: center; margin: 8px 0; font-size: 15px; }
.cost-row .name { color: var(--ink); font-weight: 600; }
.cost-row .track { background: var(--bg-sunk); border-radius: 6px; height: 22px; position: relative; overflow: hidden; }
.cost-row .fill { position: absolute; inset: 0 auto 0 0; border-radius: 6px; background: var(--teal); }
.cost-row .fill.decision { background: var(--teal); }
.cost-row .fill.small { background: var(--amber); }
.cost-row .fill.llm { background: var(--coral); }
.cost-row .fill.human { background: var(--ink); }
.cost-row .mult { text-align: right; font-weight: 700; color: var(--ink); font-variant-numeric: tabular-nums; }
.legend { display: flex; flex-wrap: wrap; gap: 14px; font-size: 13.5px; color: var(--ink-soft); margin-top: 8px; }
.legend i { display: inline-block; width: 12px; height: 12px; border-radius: 3px; margin-right: 6px; vertical-align: -1px; }

/* Diagrams */
.diagram { margin: 24px 0; background: var(--bg-raised); border: 1px solid var(--line); border-radius: var(--radius); padding: 16px; }
.diagram svg { width: 100%; height: auto; display: block; }
.diagram svg text { font-family: var(--sans); fill: var(--ink); }
.diagram .muted { fill: var(--ink-faint); }
.diagram .box { fill: var(--bg-sunk); stroke: var(--line); stroke-width: 1.5; }
.diagram .box-teal { fill: var(--teal-soft); stroke: var(--teal); stroke-width: 1.5; }
.diagram .box-coral { fill: var(--coral-soft); stroke: var(--coral); stroke-width: 1.5; }
.diagram .box-amber { fill: var(--amber-soft); stroke: var(--amber); stroke-width: 1.5; }
.diagram .box-navy { fill: var(--navy-soft); stroke: var(--ink-soft); stroke-width: 1.5; }
.diagram .arrow { stroke: var(--ink-soft); stroke-width: 2; fill: none; }
.diagram .arrow-down { stroke: var(--teal); stroke-width: 2; fill: none; stroke-dasharray: 6 5; }
.diagram .ah { fill: var(--ink-soft); }
.diagram .ah-teal { fill: var(--teal); }

/* Pager + footer */
.pager { display: flex; justify-content: space-between; gap: 16px; margin: 56px 0 20px; }
.pager a { flex: 1; display: block; padding: 14px 16px; border: 1px solid var(--line); border-radius: 12px; text-decoration: none; color: var(--ink); font-weight: 600; background: var(--bg-raised); }
.pager a span { display: block; font-size: 12px; font-weight: 700; letter-spacing: .08em; text-transform: uppercase; color: var(--ink-faint); }
.pager a:hover { border-color: var(--teal); }
.pager-next { text-align: right; }
.footer { border-top: 1px solid var(--line); margin-top: 40px; padding-top: 16px; font-size: 13.5px; }
.footer p { color: var(--ink-faint); }
details { background: var(--bg-raised); border: 1px solid var(--line); border-radius: 10px; padding: 10px 16px; margin: 14px 0; }
details summary { cursor: pointer; font-weight: 600; color: var(--ink); }
video { width: 100%; border-radius: var(--radius); border: 1px solid var(--line); background: #000; }

/* Phone width */
@media (max-width: 860px) {
  .layout { grid-template-columns: 1fr; }
  .menu-toggle { display: inline-block; }
  .sidenav { display: none; position: fixed; top: 53px; left: 0; right: 0; bottom: 0; height: auto; background: var(--bg); z-index: 4; border-right: 0; padding: 16px; }
  .sidenav.open { display: block; }
  .content { padding: 22px 16px 32px; }
  .two-col { grid-template-columns: 1fr; }
  .widget label { grid-template-columns: 1fr 64px; }
  .widget label > span:first-child { grid-column: 1 / -1; }
  .cost-row { grid-template-columns: 110px 1fr 70px; font-size: 14px; }
  .rung { grid-template-columns: 52px 1fr; padding: 12px; }
  .pager { flex-direction: column; }
  .topbar { padding: 10px 16px; }
}