:root {
  --ink: #18211d;
  --muted: #5d6b64;
  --paper: #f7f5ef;
  --card: #fffef9;
  --line: #d8ddd6;
  --green: #1c6b4b;
  --green-soft: #e2f1e8;
  --blue: #145d75;
  --blue-soft: #e1f0f5;
  --amber: #9a5914;
  --amber-soft: #fff0d8;
  --red: #9b3d35;
  --red-soft: #f9e5e1;
  --code: #17201c;
  --shadow: 0 14px 40px rgba(32, 44, 38, .08);
  color-scheme: light;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(circle at 8% 3%, rgba(28, 107, 75, .11), transparent 27rem),
    radial-gradient(circle at 92% 13%, rgba(20, 93, 117, .10), transparent 24rem),
    var(--paper);
  font-family: Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: 17px;
  line-height: 1.62;
}

a { color: var(--blue); text-underline-offset: .18em; }
a:hover { color: var(--green); }

code, pre, .mono {
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
}

code {
  padding: .08rem .3rem;
  border-radius: .3rem;
  background: rgba(20, 93, 117, .08);
  font-size: .9em;
}

pre {
  margin: 1rem 0;
  padding: 1rem 1.1rem;
  overflow-x: auto;
  border-radius: .8rem;
  color: #ecf5ef;
  background: var(--code);
  font-size: .86rem;
  line-height: 1.52;
  tab-size: 4;
}

pre code { padding: 0; color: inherit; background: transparent; }

.page {
  width: min(1120px, calc(100% - 2rem));
  margin: 0 auto;
  padding: 2rem 0 6rem;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 3.5rem;
  color: var(--muted);
  font-size: .87rem;
  letter-spacing: .03em;
}

.topbar nav { display: flex; flex-wrap: wrap; gap: 1rem; }
.topbar a { color: inherit; text-decoration: none; }

.eyebrow {
  margin: 0 0 .75rem;
  color: var(--green);
  font-weight: 750;
  font-size: .78rem;
  letter-spacing: .13em;
  text-transform: uppercase;
}

h1, h2, h3, h4 {
  margin-top: 0;
  line-height: 1.15;
  letter-spacing: -.025em;
}

h1 { max-width: 900px; margin-bottom: 1.2rem; font-size: clamp(2.6rem, 7vw, 5.6rem); }
h2 { margin-bottom: 1rem; font-size: clamp(1.8rem, 4vw, 3rem); }
h3 { margin-bottom: .65rem; font-size: 1.35rem; }
h4 { margin-bottom: .45rem; font-size: 1rem; letter-spacing: 0; }

p { margin-top: 0; }
.lede { max-width: 760px; color: var(--muted); font-size: 1.2rem; }
.small { font-size: .86rem; }
.muted { color: var(--muted); }

.hero { margin-bottom: 4rem; }

.hero-meta,
.chips {
  display: flex;
  flex-wrap: wrap;
  gap: .65rem;
  margin-top: 1.5rem;
}

.chip {
  padding: .38rem .72rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(255, 254, 249, .7);
  color: var(--muted);
  font-size: .78rem;
  font-weight: 700;
}

section { margin: 5rem 0; scroll-margin-top: 1.2rem; }

.section-intro { max-width: 730px; color: var(--muted); }

.grid-2, .grid-3, .tool-grid, .question-grid {
  display: grid;
  gap: 1rem;
}

.grid-2, .question-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.tool-grid { grid-template-columns: repeat(5, minmax(0, 1fr)); }

.card,
.question,
.diagram,
.scoreboard,
.callout {
  border: 1px solid var(--line);
  border-radius: 1rem;
  background: var(--card);
  box-shadow: var(--shadow);
}

.card, .diagram, .callout { padding: 1.3rem; }

.card p:last-child, .callout p:last-child { margin-bottom: 0; }

.tool {
  min-height: 150px;
  padding: 1rem;
  border-top: 4px solid var(--green);
  border-radius: .8rem;
  background: var(--card);
  box-shadow: var(--shadow);
}

.tool:nth-child(2) { border-color: var(--blue); }
.tool:nth-child(3) { border-color: var(--amber); }
.tool:nth-child(4) { border-color: #7254a5; }
.tool:nth-child(5) { border-color: var(--red); }
.tool strong { display: block; margin-bottom: .35rem; }
.tool span { color: var(--muted); font-size: .86rem; line-height: 1.45; }

.flow {
  display: flex;
  align-items: stretch;
  gap: .5rem;
  margin: 1rem 0;
}

.flow-node {
  display: grid;
  flex: 1;
  min-height: 76px;
  place-items: center;
  padding: .7rem;
  border: 1px solid var(--line);
  border-radius: .65rem;
  background: #fff;
  text-align: center;
  font-size: .88rem;
  font-weight: 700;
}

.arrow { align-self: center; color: var(--green); font-size: 1.4rem; font-weight: 900; }

.pair {
  display: grid;
  grid-template-columns: 1fr 1fr;
  overflow: hidden;
  margin: .7rem 0;
  border: 2px solid var(--ink);
  border-radius: .65rem;
  background: #fff;
}

.pair > div { padding: .75rem; text-align: center; }
.pair > div + div { border-left: 1px solid var(--ink); }
.pair b { display: block; font-size: .72rem; letter-spacing: .07em; text-transform: uppercase; }
.pair span { font-family: "SFMono-Regular", Consolas, monospace; font-size: .86rem; }

.question {
  position: relative;
  overflow: hidden;
  padding: 1.3rem;
}

.question::before {
  position: absolute;
  inset: 0 auto 0 0;
  width: 5px;
  background: var(--green);
  content: "";
}

.question.concurrency::before { background: var(--blue); }

.q-number {
  display: inline-grid;
  width: 2rem;
  height: 2rem;
  margin-bottom: .8rem;
  place-items: center;
  border-radius: 50%;
  color: #fff;
  background: var(--green);
  font-weight: 800;
  font-size: .8rem;
}

.concurrency .q-number { background: var(--blue); }
.question .ask { min-height: 5.2rem; font-weight: 680; }

details.answer {
  margin-top: 1rem;
  border-top: 1px solid var(--line);
  padding-top: .75rem;
}

details.answer summary {
  cursor: pointer;
  color: var(--green);
  font-weight: 750;
  list-style: none;
}

details.answer summary::-webkit-details-marker { display: none; }
details.answer summary::before { content: "+ "; }
details.answer[open] summary::before { content: "− "; }
.concurrency details.answer summary { color: var(--blue); }
.answer-body { padding-top: .85rem; }

.signals {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: .75rem;
  margin-top: 1rem;
}

.signal {
  padding: .75rem;
  border-radius: .6rem;
  font-size: .84rem;
  line-height: 1.45;
}

.signal.good { color: #184d37; background: var(--green-soft); }
.signal.risk { color: #77342d; background: var(--red-soft); }
.signal b { display: block; margin-bottom: .2rem; }

.probe {
  margin-top: .85rem;
  padding-left: .8rem;
  border-left: 3px solid var(--amber);
  color: var(--muted);
  font-size: .88rem;
}

.source { margin-top: .8rem; color: var(--muted); font-size: .78rem; }

.score-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: .7rem;
  margin-top: 1rem;
  padding-top: .8rem;
  border-top: 1px dashed var(--line);
  color: var(--muted);
  font-size: .78rem;
}

.score-buttons { display: flex; gap: .35rem; }

button {
  border: 1px solid var(--line);
  border-radius: .45rem;
  padding: .42rem .7rem;
  color: var(--ink);
  background: #fff;
  font: inherit;
  font-size: .78rem;
  font-weight: 750;
  cursor: pointer;
}

button:hover, button.selected { border-color: var(--green); background: var(--green-soft); }
button:focus-visible, summary:focus-visible, a:focus-visible { outline: 3px solid #e3a648; outline-offset: 3px; }

.toolbar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: .55rem;
  margin: 1.2rem 0;
}

.timer {
  min-width: 5.2rem;
  color: var(--green);
  font-family: "SFMono-Regular", Consolas, monospace;
  font-size: 1.25rem;
  font-weight: 800;
}

.timer.expired { color: var(--red); }

.scoreboard {
  position: sticky;
  bottom: 1rem;
  z-index: 4;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  margin: 2rem auto 0;
  padding: .8rem 1rem;
  background: rgba(255, 254, 249, .94);
  backdrop-filter: blur(12px);
}

.score-total { font-size: 1.25rem; font-weight: 850; }

.rubric {
  width: 100%;
  border-collapse: collapse;
  margin: 1rem 0;
  font-size: .9rem;
}

.rubric th, .rubric td { padding: .75rem; border-bottom: 1px solid var(--line); text-align: left; vertical-align: top; }
.rubric th { color: var(--muted); font-size: .72rem; letter-spacing: .07em; text-transform: uppercase; }

.callout { border-left: 5px solid var(--amber); background: var(--amber-soft); }
.callout.blue { border-left-color: var(--blue); background: var(--blue-soft); }
.callout.green { border-left-color: var(--green); background: var(--green-soft); }

.agenda {
  display: grid;
  grid-template-columns: 1fr 2fr 2fr 1fr;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: .8rem;
}

.agenda > div { min-height: 100px; padding: .8rem; border-right: 1px solid var(--line); background: var(--card); }
.agenda > div:last-child { border: 0; }
.agenda b { display: block; color: var(--green); font-size: 1.2rem; }
.agenda span { color: var(--muted); font-size: .78rem; }

.checklist { padding-left: 1.2rem; }
.checklist li { margin-bottom: .55rem; }

footer { margin-top: 5rem; padding-top: 1.5rem; border-top: 1px solid var(--line); color: var(--muted); font-size: .85rem; }

.print-only { display: none; }

@media (max-width: 860px) {
  .tool-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .grid-2, .question-grid, .grid-3 { grid-template-columns: 1fr; }
  .question .ask { min-height: auto; }
  .agenda { grid-template-columns: 1fr 1fr; }
  .agenda > div:nth-child(2) { border-right: 0; }
  .agenda > div:nth-child(-n+2) { border-bottom: 1px solid var(--line); }
}

@media (max-width: 570px) {
  body { font-size: 16px; }
  .page { width: min(100% - 1.15rem, 1120px); padding-top: 1rem; }
  .topbar { align-items: flex-start; margin-bottom: 2.2rem; }
  .topbar nav { justify-content: flex-end; }
  .tool-grid, .signals { grid-template-columns: 1fr; }
  .flow { flex-direction: column; }
  .arrow { transform: rotate(90deg); }
  .scoreboard { align-items: flex-start; flex-direction: column; }
}

@media print {
  :root { --paper: #fff; --card: #fff; --shadow: none; }
  body { background: #fff; color: #000; font-size: 10pt; }
  .page { width: 100%; padding: 0; }
  .topbar, .toolbar, .scoreboard, .screen-only { display: none !important; }
  .print-only { display: block; }
  h1 { font-size: 28pt; }
  h2 { font-size: 20pt; }
  section { margin: 1.5rem 0; }
  .card, .question, .diagram, .callout, .tool { box-shadow: none; break-inside: avoid; }
  .question-grid, .grid-2 { gap: .5rem; }
  details.answer > * { display: block; }
  details.answer summary { display: none; }
  .answer-body { display: block !important; }
  a { color: #000; text-decoration: none; }
  pre { white-space: pre-wrap; }
}