/* === TOKENS === */
:root {
  --bg: #FAFAF8;
  --bg-card: #FFFFFF;
  --bg-sunken: #F4F3F9;
  --text: #1A1A2E;
  --text-muted: #5C5C7A;
  --accent: #446B7A;                /* steel blue */
  --accent-dark: #345560;
  --accent-light: #DEEBF0;
  --accent-secondary: #D17A4A;      /* rust */
  --accent-secondary-light: #F7E6DA;
  --warn: #D97706;
  --warn-light: #FDF1E0;
  --ok: #2D7D46;
  --ok-light: #E8F5EC;
  --err: #DC2626;
  --err-light: #FEE8E8;
  --grid-line: rgba(68, 107, 122, 0.07);
  --border: #E5E3EC;
  --shadow: rgba(40, 30, 90, 0.07);
  --radius: 0.75rem;
  --mono: 'SF Mono', 'JetBrains Mono', 'Fira Code', ui-monospace, Menlo, Consolas, monospace;

  /* light code theme — every code surface uses these (never dark) */
  --code-bg:       #EEF2F5;
  --code-bg-soft:  #E1E7EC;
  --code-border:   #D3DAE0;
  --code-fg:       #1F2533;
  --code-cm:       #7A8590;
  --code-kw:       #9C2D6E;
  --code-ty:       #2D6E78;
  --code-fn:       #2F5FA3;
  --code-op:       #B5552A;
  --code-st:       #3B7A4B;
}

/* === RESET === */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: 'Inter', system-ui, -apple-system, 'Segoe UI', sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

/* === LAYOUT === */
.container { max-width: 1040px; margin: 0 auto; padding: 0 1.5rem; }
.wide { max-width: 1040px; }

/* === HEADER === */
header {
  position: sticky; top: 0; z-index: 100;
  background: rgba(250, 250, 248, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: border-color 0.3s, box-shadow 0.3s;
}
header.scrolled {
  border-bottom-color: var(--border);
  box-shadow: 0 1px 8px var(--shadow);
}
header .container {
  display: flex; align-items: center; justify-content: space-between;
  height: 56px; max-width: 1040px;
}
.wordmark {
  display: flex; align-items: center; gap: 0.5rem;
  font-weight: 600; font-size: 0.95rem; color: var(--text);
}
.wordmark:hover { text-decoration: none; }
.wordmark .mk {
  width: 26px; height: 26px; border-radius: 7px;
  background: var(--accent); color: #fff;
  display: grid; place-items: center;
}
.wordmark .mk svg { display: block; }
.wordmark span { opacity: 0.5; font-weight: 400; }
header nav { display: flex; gap: 1.2rem; }
header nav a {
  font-size: 0.85rem; color: var(--text-muted);
  transition: color 0.2s;
}
header nav a:hover { color: var(--accent); text-decoration: none; }
/* scroll progress */
.progress {
  position: absolute; left: 0; bottom: -1px; height: 2px;
  background: var(--accent); width: 0%;
  transition: width 0.1s linear;
}

/* === CHAPTER STRIP === */
.ch-strip {
  background: var(--bg);
  border-bottom: 1px solid var(--border);
  overflow-x: auto;
  scrollbar-width: none;
  -ms-overflow-style: none;
}
.ch-strip::-webkit-scrollbar { display: none; }
.ch-strip .container {
  display: flex; align-items: center; gap: 0.4rem;
  padding-top: 0.55rem; padding-bottom: 0.55rem;
  max-width: 1040px;
}
.ch-pill {
  flex-shrink: 0;
  display: inline-flex; align-items: center; gap: 0.45rem;
  font-size: 0.78rem; color: var(--text-muted);
  padding: 0.32rem 0.7rem; border-radius: 999px;
  border: 1px solid var(--border); background: var(--bg-card);
  transition: all 0.15s ease-out;
  text-decoration: none;
  white-space: nowrap;
}
.ch-pill:hover { color: var(--accent-dark); border-color: var(--accent); text-decoration: none; }
.ch-pill .ch-num {
  font-family: var(--mono); font-weight: 700; font-size: 0.7rem;
  color: var(--accent);
}
.ch-pill .ch-name { font-weight: 500; }
.ch-pill.current {
  background: var(--accent); color: #fff;
  border-color: var(--accent);
}
.ch-pill.current .ch-num { color: rgba(255,255,255,0.75); }
.ch-pill.current:hover { color: #fff; background: var(--accent-dark); border-color: var(--accent-dark); }

/* coming-soon pills (future chapters) */
.ch-pill-soon {
  flex-shrink: 0;
  display: inline-flex; align-items: center; gap: 0.45rem;
  font-size: 0.78rem; color: var(--text-muted);
  padding: 0.32rem 0.7rem; border-radius: 999px;
  border: 1px dashed var(--border); background: transparent;
  white-space: nowrap; cursor: default;
}
.ch-pill-soon .ch-num { font-family: var(--mono); font-weight: 700; font-size: 0.7rem; color: var(--text-muted); }
.ch-pill-soon .ch-name { font-weight: 500; opacity: 0.7; }

.ch-divider {
  width: 12px; height: 1px; background: var(--border); flex-shrink: 0;
}
@media (max-width: 767px) {
  .ch-pill .ch-name, .ch-pill-soon .ch-name { display: none; }
  .ch-pill, .ch-pill-soon { padding: 0.28rem 0.5rem; }
  .ch-divider { width: 6px; }
}

/* === HERO === */
.hero {
  padding: 4.5rem 0 3rem;
  text-align: center;
  position: relative;
  overflow: hidden;
  background-image:
    linear-gradient(var(--grid-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-line) 1px, transparent 1px);
  background-size: 28px 28px;
}
.hero::after {
  content: '';
  position: absolute; bottom: 0; left: 0; right: 0; height: 80px;
  background: linear-gradient(transparent, var(--bg));
  pointer-events: none;
}
.eyebrow {
  display: inline-flex; align-items: center; gap: 0.5rem;
  font-size: 0.72rem; font-weight: 600;
  text-transform: uppercase; letter-spacing: 0.12em;
  color: var(--accent-dark);
  background: var(--accent-light);
  padding: 0.35rem 0.8rem; border-radius: 999px;
  margin-bottom: 1.25rem;
  animation: fadeUp 0.6s ease-out both;
}
.hero-title {
  font-family: 'Fraunces', Georgia, serif;
  font-size: 3rem; font-weight: 600;
  letter-spacing: -0.02em; line-height: 1.1;
  margin-bottom: 0.85rem;
  animation: fadeUp 0.6s ease-out 0.08s both;
}
.hero-title em { font-style: italic; color: var(--accent); }
.hero-subtitle {
  font-size: 1.15rem; color: var(--text-muted);
  max-width: 600px; margin: 0 auto 2rem;
  animation: fadeUp 0.6s ease-out 0.16s both;
}
.hero-arrows { animation: fadeUp 0.6s ease-out 0.28s both; }

@keyframes fadeUp {
  from { opacity: 0; transform: translateY(16px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* === SECTIONS === */
section.lesson { padding: 1rem 0; }
.block { margin: 2.75rem 0; }
h2.sec {
  font-family: 'Fraunces', Georgia, serif;
  font-size: 1.7rem; font-weight: 600; letter-spacing: -0.01em;
  margin-bottom: 0.4rem;
  scroll-margin-top: 72px;
}
h2.sec .num {
  font-family: var(--mono); font-size: 0.95rem; font-weight: 500;
  color: var(--accent); margin-right: 0.5rem;
  vertical-align: 0.12em;
}
h3.sub { font-size: 1.1rem; font-weight: 600; margin: 1.5rem 0 0.5rem; }
p.lead { font-size: 1.05rem; color: var(--text-muted); margin-bottom: 1rem; }
.prose p { margin-bottom: 0.9rem; }
.prose ul { margin: 0.4rem 0 1rem 1.3rem; }
.prose li { margin-bottom: 0.35rem; }

/* inline mono-ish */
.m {
  font-family: var(--mono); font-size: 0.92em;
  background: var(--bg-sunken);
  padding: 0.08em 0.38em; border-radius: 4px;
  white-space: nowrap;
}
.m.obj { color: var(--accent-secondary); background: var(--accent-secondary-light); }
.m.mor { color: var(--accent-dark); background: var(--accent-light); }

/* === CALLOUT === */
.callout {
  display: flex; gap: 0.85rem;
  background: var(--accent-light);
  border: 1px solid #c7dde6;
  border-left: 3px solid var(--accent);
  border-radius: var(--radius);
  padding: 1rem 1.15rem;
  margin: 1.5rem 0;
  font-size: 0.95rem;
}
.callout .ic { font-size: 1.2rem; flex-shrink: 0; line-height: 1.5; }
.callout.warn { background: var(--warn-light); border-color: #f3dcb6; border-left-color: var(--warn); }
.callout strong { color: var(--accent-dark); }
.callout.warn strong { color: var(--warn); }

/* === FIGURE / WIDGET === */
.widget {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem;
  margin: 1.5rem 0;
  box-shadow: 0 1px 3px var(--shadow);
}
.widget-head {
  display: flex; align-items: center; justify-content: space-between;
  flex-wrap: wrap; gap: 0.6rem;
  margin-bottom: 0.5rem;
}
.widget-title {
  font-size: 0.78rem; font-weight: 600;
  text-transform: uppercase; letter-spacing: 0.08em;
  color: var(--text-muted);
  display: flex; align-items: center; gap: 0.45rem;
}
.widget-title .dot { width: 8px; height: 8px; border-radius: 50%; background: var(--accent); }
.hint { font-size: 0.8rem; color: var(--text-muted); }

svg.diagram { width: 100%; height: auto; display: block; touch-action: none; user-select: none; }
.diagram-wrap { background: var(--bg-sunken); border-radius: 0.5rem; padding: 0.5rem; }

/* === BUTTONS / CONTROLS === */
.controls { display: flex; flex-wrap: wrap; gap: 0.5rem; margin-top: 0.85rem; align-items: center; }
.btn {
  font: inherit; font-size: 0.85rem; font-weight: 500;
  border: 1px solid var(--border); background: var(--bg-card);
  color: var(--text); border-radius: 8px;
  padding: 0.45rem 0.85rem; cursor: pointer;
  transition: all 0.15s ease-out;
  display: inline-flex; align-items: center; gap: 0.4rem;
}
.btn:hover { border-color: var(--accent); color: var(--accent-dark); }
.btn.primary { background: var(--accent); color: #fff; border-color: var(--accent); }
.btn.primary:hover { background: var(--accent-dark); color: #fff; }
.btn.danger { background: var(--accent-secondary); color: #fff; border-color: var(--accent-secondary); }
.btn.danger:hover { background: #b9623a; color: #fff; }
.btn.active { background: var(--accent-light); border-color: var(--accent); color: var(--accent-dark); }
.btn:disabled { opacity: 0.45; cursor: not-allowed; }
.readout {
  font-family: var(--mono); font-size: 0.85rem;
  color: var(--text-muted); margin-left: auto;
}
select.pick {
  font: inherit; font-family: var(--mono); font-size: 0.85rem;
  padding: 0.3rem 0.5rem; border-radius: 6px;
  border: 1px solid var(--border); background: var(--bg-card); color: var(--text);
  cursor: pointer;
}
input[type=range].slider {
  -webkit-appearance: none; appearance: none;
  height: 5px; border-radius: 999px;
  background: var(--code-bg-soft);
  outline: none; cursor: pointer; flex: 1; min-width: 140px;
}
input[type=range].slider::-webkit-slider-thumb {
  -webkit-appearance: none; appearance: none;
  width: 18px; height: 18px; border-radius: 50%;
  background: var(--accent); border: 2px solid #fff;
  box-shadow: 0 1px 3px var(--shadow); cursor: pointer;
}
input[type=range].slider::-moz-range-thumb {
  width: 18px; height: 18px; border-radius: 50%;
  background: var(--accent); border: 2px solid #fff; cursor: pointer;
}

/* === CODE / LANGUAGE TOGGLE (LIGHT THEME) === */
.code-card { border: 1px solid var(--code-border); border-radius: var(--radius); overflow: hidden; margin: 1.5rem 0; }
.code-tabs { display: flex; background: var(--code-bg-soft); border-bottom: 1px solid var(--code-border); }
.code-tab {
  font: inherit; font-size: 0.82rem; font-weight: 500;
  font-family: var(--mono);
  color: var(--text-muted); background: transparent; border: none;
  padding: 0.6rem 1.05rem; cursor: pointer;
  border-bottom: 2px solid transparent;
  transition: color 0.15s, border-color 0.15s;
}
.code-tab:hover { color: var(--text); }
.code-tab.active { color: var(--accent-dark); border-bottom-color: var(--accent); }
.code-tab .lang-ic { opacity: 0.9; margin-right: 0.4rem; }
pre.code {
  margin: 0; padding: 1.1rem 1.2rem;
  background: var(--code-bg); color: var(--code-fg);
  font-family: var(--mono); font-size: 0.84rem; line-height: 1.7;
  overflow-x: auto;
}
pre.code .cm { color: var(--code-cm); font-style: italic; } /* comment */
pre.code .kw { color: var(--code-kw); }                     /* keyword */
pre.code .ty { color: var(--code-ty); }                     /* type */
pre.code .fn { color: var(--code-fn); }                     /* function/value name */
pre.code .op { color: var(--code-op); }                     /* operator */
pre.code .st { color: var(--code-st); }                     /* string/literal */
.code-pane { display: none; }
.code-pane.active { display: block; }

/* === QUIZ === */
.quiz-q { margin-bottom: 1.4rem; }
.quiz-q:last-child { margin-bottom: 0; }
.quiz-q .q { font-weight: 600; margin-bottom: 0.6rem; }
.quiz-q .q .qn {
  font-family: var(--mono); color: var(--accent); font-size: 0.85rem; margin-right: 0.4rem;
}
.opt {
  display: block; width: 100%; text-align: left;
  font: inherit; font-size: 0.92rem;
  background: var(--bg-card); border: 1px solid var(--border);
  border-radius: 8px; padding: 0.6rem 0.85rem; margin-bottom: 0.5rem;
  cursor: pointer; transition: all 0.12s ease-out;
  display: flex; align-items: center; gap: 0.6rem;
}
.opt:hover:not(.locked) { border-color: var(--accent); background: var(--accent-light); }
.opt .mark { width: 18px; flex-shrink: 0; font-weight: 700; }
.opt.correct { border-color: var(--ok); background: var(--ok-light); color: #1b5e2e; }
.opt.wrong { border-color: var(--err); background: var(--err-light); color: #b91c1c; }
.opt.locked { cursor: default; }
.quiz-fb { font-size: 0.88rem; margin-top: 0.4rem; min-height: 1.2em; color: var(--text-muted); }
.quiz-fb.show.ok { color: var(--ok); }
.quiz-fb.show.no { color: var(--err); }

/* === NINES DIAL === */
.nines-readrow { display: flex; flex-wrap: wrap; gap: 0.5rem; margin-top: 0.85rem; }
.nines-stat {
  flex: 1; min-width: 110px;
  background: var(--code-bg); border: 1px solid var(--code-border);
  border-radius: 8px; padding: 0.6rem 0.7rem;
}
.nines-stat .k { font-size: 0.68rem; text-transform: uppercase; letter-spacing: 0.07em; color: var(--text-muted); }
.nines-stat .v { font-family: var(--mono); font-size: 1.05rem; font-weight: 600; color: var(--accent-dark); }

/* === GOLDEN SIGNALS CONSOLE === */
.gs-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 0.6rem; }
.gs-panel {
  background: var(--code-bg); border: 1px solid var(--code-border);
  border-radius: 8px; padding: 0.55rem 0.65rem;
  transition: border-color 0.2s, box-shadow 0.2s;
}
.gs-panel.alert { border-color: var(--accent-secondary); box-shadow: 0 0 0 2px var(--accent-secondary-light); }
.gs-panel .gs-title {
  font-size: 0.72rem; font-weight: 600; text-transform: uppercase; letter-spacing: 0.06em;
  color: var(--text-muted); display: flex; justify-content: space-between; align-items: baseline;
  transition: color 0.2s;
}
.gs-panel.alert .gs-title { color: var(--accent-secondary); }
.gs-panel .gs-val { font-family: var(--mono); font-size: 0.78rem; color: var(--accent-dark); }
.gs-panel svg { width: 100%; height: auto; display: block; margin-top: 0.25rem; }
@media (max-width: 520px) { .gs-grid { grid-template-columns: 1fr; } }

/* === NEXT / FOOTER === */
.next-card {
  display: flex; align-items: center; gap: 1rem;
  background: linear-gradient(135deg, var(--accent-light), var(--accent-secondary-light));
  border: 1px solid #c7dde6; border-radius: var(--radius);
  padding: 1.25rem 1.4rem; margin: 2.5rem 0 1rem;
}
.next-card .big { font-size: 1.6rem; }
.next-card .t1 { font-size: 0.75rem; text-transform: uppercase; letter-spacing: 0.1em; color: var(--text-muted); font-weight: 600; }
.next-card .t2 { font-weight: 600; font-size: 1.05rem; }
.next-card .t3 { font-size: 0.88rem; color: var(--text-muted); }
.next-card .lock { margin-left: auto; font-size: 0.8rem; color: var(--text-muted); }
a.next-card { color: inherit; text-decoration: none; transition: transform 0.2s ease-out, box-shadow 0.2s ease-out; }
a.next-card:hover { transform: translateY(-2px); box-shadow: 0 6px 18px var(--shadow); text-decoration: none; }
.next-card .arrow { margin-left: auto; font-size: 1.4rem; color: var(--accent-dark); transition: transform 0.2s ease-out; }
a.next-card:hover .arrow { transform: translateX(4px); }
.badge-soon {
  margin-left: auto; font-size: 0.72rem; font-weight: 600;
  text-transform: uppercase; letter-spacing: 0.08em;
  color: var(--accent-dark); background: var(--bg-card);
  border: 1px dashed var(--accent); border-radius: 999px;
  padding: 0.3rem 0.7rem;
}
.next-card.next-soon { opacity: 0.7; cursor: default; }
.next-card.next-soon:hover { transform: none; box-shadow: none; }

footer {
  padding: 2.5rem 0; text-align: center;
  font-size: 0.8rem; color: var(--text-muted);
  border-top: 1px solid var(--border); margin-top: 1rem;
}

/* === REDUCED MOTION === */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; }
}

/* === RESPONSIVE === */
@media (max-width: 767px) {
  .hero { padding: 3rem 0 2rem; }
  .hero-title { font-size: 2.1rem; }
  .hero-subtitle { font-size: 1rem; }
  h2.sec { font-size: 1.4rem; }
  header nav a:not(.nav-keep) { display: none; }
  .readout { margin-left: 0; width: 100%; }
}


/* ===== ch02 widget styles ===== */
/* ============================================================
   Chapter 2 — SLOs & Error Budgets
   Chapter-specific rules. All classes prefixed `ch02-`.
   Shared classes (.widget, .controls, .readout, .btn, .quiz-*,
   .code-card, etc.) come from style.css — do not duplicate them.
   ============================================================ */

/* shared readout grid used by the three widgets */
.ch02-readrow {
  display: flex; flex-wrap: wrap; gap: 0.5rem; margin-top: 0.85rem;
}
.ch02-stat {
  flex: 1; min-width: 120px;
  background: var(--code-bg); border: 1px solid var(--code-border);
  border-radius: 8px; padding: 0.6rem 0.7rem;
}
.ch02-stat .k {
  font-size: 0.68rem; text-transform: uppercase; letter-spacing: 0.07em;
  color: var(--text-muted);
}
.ch02-stat .v {
  font-family: var(--mono); font-size: 1.05rem; font-weight: 600;
  color: var(--accent-dark);
}
/* a stat that has gone "bad" (over budget / on fire) tints rust */
.ch02-stat.bad { background: var(--err-light); border-color: #f3c9c9; }
.ch02-stat.bad .v { color: var(--err); }
.ch02-stat.good { background: var(--ok-light); border-color: #c6e4d0; }
.ch02-stat.good .v { color: var(--ok); }

/* a verdict line under a widget — full-width sentence */
.ch02-verdict {
  margin-top: 0.7rem;
  font-size: 0.9rem; line-height: 1.5;
  color: var(--text-muted);
  background: var(--bg-sunken);
  border: 1px solid var(--border);
  border-left: 3px solid var(--accent);
  border-radius: 8px;
  padding: 0.6rem 0.8rem;
}
.ch02-verdict.warn { border-left-color: var(--accent-secondary); }
.ch02-verdict.err  { border-left-color: var(--err); }
.ch02-verdict b { color: var(--accent-dark); }
.ch02-verdict.err b { color: var(--err); }
.ch02-verdict.warn b { color: var(--accent-secondary); }

/* small inline window-toggle buttons for the burn-rate tuner */
.ch02-seg { display: inline-flex; gap: 0.3rem; flex-wrap: wrap; }
.ch02-seg .btn { padding: 0.35rem 0.7rem; font-size: 0.8rem; }

/* a tidy two-column "vantage point" table for section 4 */
.ch02-vantage {
  width: 100%; border-collapse: collapse; margin: 1.4rem 0 0.4rem;
  font-size: 0.9rem;
}
.ch02-vantage th, .ch02-vantage td {
  text-align: left; padding: 0.55rem 0.7rem;
  border-bottom: 1px solid var(--border); vertical-align: top;
}
.ch02-vantage thead th {
  font-size: 0.7rem; text-transform: uppercase; letter-spacing: 0.07em;
  color: var(--text-muted); font-weight: 600;
  border-bottom: 1px solid var(--code-border);
}
.ch02-vantage tbody td:first-child {
  font-weight: 600; color: var(--accent-dark); white-space: nowrap;
}
.ch02-vantage .lie { color: var(--accent-secondary); }
@media (max-width: 600px) {
  .ch02-vantage, .ch02-vantage thead, .ch02-vantage tbody,
  .ch02-vantage tr, .ch02-vantage th, .ch02-vantage td { display: block; }
  .ch02-vantage thead { display: none; }
  .ch02-vantage tr { border-bottom: 1px solid var(--code-border); padding: 0.4rem 0; }
  .ch02-vantage td { border: none; padding: 0.2rem 0; }
  .ch02-vantage tbody td:first-child { color: var(--accent-dark); }
}

/* a signed-policy "form" block for section 6 */
.ch02-policy {
  background: var(--bg-card); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 1.1rem 1.25rem; margin: 1.5rem 0;
  box-shadow: 0 1px 3px var(--shadow);
}
.ch02-policy h4 {
  font-size: 0.72rem; text-transform: uppercase; letter-spacing: 0.08em;
  color: var(--text-muted); margin-bottom: 0.7rem; font-weight: 600;
}
.ch02-policy ul { margin: 0 0 0.8rem 0; list-style: none; }
.ch02-policy li {
  display: flex; gap: 0.6rem; align-items: baseline;
  padding: 0.4rem 0; border-bottom: 1px dashed var(--border);
  font-size: 0.92rem;
}
.ch02-policy li:last-of-type { border-bottom: none; }
.ch02-policy .trig {
  font-family: var(--mono); font-size: 0.78rem; font-weight: 700;
  color: var(--accent-secondary); white-space: nowrap; min-width: 78px;
}
.ch02-sign {
  display: flex; flex-wrap: wrap; gap: 0.5rem; margin-top: 0.4rem;
}
.ch02-sign span {
  font-size: 0.78rem; font-family: var(--mono);
  background: var(--accent-light); color: var(--accent-dark);
  border-radius: 999px; padding: 0.25rem 0.7rem;
}

/* legend dots used inside widget SVG captions */
.ch02-legend {
  display: flex; flex-wrap: wrap; gap: 0.8rem; margin-top: 0.5rem;
  font-size: 0.78rem; color: var(--text-muted);
}
.ch02-legend span { display: inline-flex; align-items: center; gap: 0.35rem; }
.ch02-legend i { width: 11px; height: 11px; border-radius: 3px; display: inline-block; }


/* ===== ch03 widget styles ===== */
/* ============================================================
   Chapter 3 — Eliminating Toil
   Chapter-specific rules. All classes prefixed `ch03-`.
   Shared classes (.widget, .controls, .readout, .btn, .quiz-*,
   .code-card, etc.) come from style.css — do not duplicate them.
   ============================================================ */

/* ---- shared stat row + verdict (mirrors ch02 idiom) ---- */
.ch03-readrow { display: flex; flex-wrap: wrap; gap: 0.5rem; margin-top: 0.85rem; }
.ch03-stat {
  flex: 1; min-width: 120px;
  background: var(--code-bg); border: 1px solid var(--code-border);
  border-radius: 8px; padding: 0.6rem 0.7rem;
}
.ch03-stat .k {
  font-size: 0.68rem; text-transform: uppercase; letter-spacing: 0.07em;
  color: var(--text-muted);
}
.ch03-stat .v {
  font-family: var(--mono); font-size: 1.05rem; font-weight: 600;
  color: var(--accent-dark);
}
.ch03-stat.bad  { background: var(--err-light); border-color: #f3c9c9; }
.ch03-stat.bad .v { color: var(--err); }
.ch03-stat.good { background: var(--ok-light); border-color: #c6e4d0; }
.ch03-stat.good .v { color: var(--ok); }

.ch03-verdict {
  margin-top: 0.7rem;
  font-size: 0.9rem; line-height: 1.5;
  color: var(--text-muted);
  background: var(--bg-sunken);
  border: 1px solid var(--border);
  border-left: 3px solid var(--accent);
  border-radius: 8px;
  padding: 0.6rem 0.8rem;
}
.ch03-verdict.warn { border-left-color: var(--accent-secondary); }
.ch03-verdict.err  { border-left-color: var(--err); }
.ch03-verdict b { color: var(--accent-dark); }
.ch03-verdict.err b { color: var(--err); }
.ch03-verdict.warn b { color: var(--accent-secondary); }

/* ---- legend dots inside widget captions ---- */
.ch03-legend {
  display: flex; flex-wrap: wrap; gap: 0.8rem; margin-top: 0.5rem;
  font-size: 0.78rem; color: var(--text-muted);
}
.ch03-legend span { display: inline-flex; align-items: center; gap: 0.35rem; }
.ch03-legend i { width: 11px; height: 11px; border-radius: 3px; display: inline-block; }

/* ============================================================
   Widget 1 — The Toil Scorer: toggle chips + presets
   ============================================================ */
.ch03-chiprow { display: flex; flex-wrap: wrap; gap: 0.45rem; margin-top: 0.85rem; }
.ch03-chip {
  font-family: var(--mono); font-size: 0.78rem;
  background: var(--bg-card); color: var(--text-muted);
  border: 1px solid var(--border); border-radius: 999px;
  padding: 0.4rem 0.85rem; cursor: pointer;
  transition: background .12s, border-color .12s, color .12s;
  display: inline-flex; align-items: center; gap: 0.4rem;
}
.ch03-chip:hover { border-color: var(--accent-secondary); color: var(--accent-secondary); }
.ch03-chip .tick {
  width: 14px; height: 14px; border-radius: 4px;
  border: 1.5px solid currentColor; display: inline-grid; place-items: center;
  font-size: 0.62rem; line-height: 1; color: inherit;
}
.ch03-chip.on {
  background: var(--accent-secondary-light); color: var(--accent-secondary);
  border-color: var(--accent-secondary); font-weight: 600;
}
.ch03-chip.on .tick { background: var(--accent-secondary); border-color: var(--accent-secondary); color: #fff; }

.ch03-presets { display: flex; flex-wrap: wrap; gap: 0.4rem; margin-top: 0.8rem; }
.ch03-presets .btn { padding: 0.35rem 0.7rem; font-size: 0.78rem; }

/* ============================================================
   Widget 3 — The Automation Ladder: clickable rung buttons
   ============================================================ */
.ch03-rungrow { display: flex; flex-direction: column; gap: 0.35rem; margin-top: 0.85rem; }
.ch03-rung {
  display: flex; align-items: center; gap: 0.6rem; text-align: left;
  background: var(--bg-card); border: 1px solid var(--border);
  border-radius: 10px; padding: 0.5rem 0.7rem; cursor: pointer;
  transition: background .12s, border-color .12s;
  font-size: 0.86rem; color: var(--text);
}
.ch03-rung:hover { border-color: var(--accent); }
.ch03-rung.on {
  background: var(--accent-light); border-color: var(--accent);
}
.ch03-rung .rn {
  flex: 0 0 auto; width: 22px; height: 22px; border-radius: 6px;
  display: grid; place-items: center;
  font-family: var(--mono); font-size: 0.78rem; font-weight: 700;
  background: var(--code-bg-soft); color: var(--accent-dark);
}
.ch03-rung.on .rn { background: var(--accent); color: #fff; }
.ch03-rung .rl { flex: 1; }
.ch03-rung .rl b { color: var(--accent-dark); }

/* ============================================================
   Section 4 — small inline "ladder at a glance" list reuse
   (no extra rules needed; covered above)
   ============================================================ */


/* ===== ch04 widget styles ===== */
/* ============================================================
   Chapter 4 — Monitoring · chapter-specific styles
   All classes prefixed ch04- · light code surfaces only.
   ============================================================ */

/* === The four jobs grid (section 1) === */
.ch04-jobs {
  display: grid; grid-template-columns: repeat(2, 1fr); gap: 0.7rem;
  margin: 1.4rem 0 0.4rem;
}
.ch04-job {
  background: var(--code-bg); border: 1px solid var(--code-border);
  border-radius: 8px; padding: 0.8rem 0.9rem;
}
.ch04-job.ch04-job-page {
  border-color: var(--accent-secondary);
  box-shadow: inset 3px 0 0 var(--accent-secondary);
}
.ch04-job .ch04-job-ic { font-size: 1.2rem; }
.ch04-job .ch04-job-t {
  font-weight: 600; font-size: 0.95rem; margin: 0.2rem 0 0.15rem;
}
.ch04-job .ch04-job-d { font-size: 0.83rem; color: var(--text-muted); line-height: 1.5; }
.ch04-job .ch04-tag {
  display: inline-block; margin-top: 0.4rem;
  font-family: var(--mono); font-size: 0.68rem; font-weight: 600;
  text-transform: uppercase; letter-spacing: 0.06em;
  padding: 0.1rem 0.45rem; border-radius: 999px;
}
.ch04-tag-quiet { color: var(--accent-dark); background: var(--accent-light); }
.ch04-tag-loud  { color: var(--accent-secondary); background: var(--accent-secondary-light); }
@media (max-width: 600px) { .ch04-jobs { grid-template-columns: 1fr; } }

/* === Widget 1 · Page or Ticket? sorter === */
.ch04-sort-stage {
  background: var(--bg-sunken); border-radius: 0.5rem;
  padding: 1.4rem 1rem; min-height: 168px;
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  gap: 0.5rem; text-align: center;
}
.ch04-sort-card {
  background: var(--code-bg); border: 1px solid var(--code-border);
  border-radius: 10px; padding: 1rem 1.1rem; max-width: 460px; width: 100%;
  transition: transform 0.18s ease-out, opacity 0.18s ease-out;
}
.ch04-sort-card .ch04-sort-sig {
  font-family: var(--mono); font-size: 0.95rem; font-weight: 600; color: var(--code-fg);
}
.ch04-sort-card .ch04-sort-sub {
  font-size: 0.8rem; color: var(--text-muted); margin-top: 0.25rem;
}
.ch04-sort-feedback {
  font-size: 0.86rem; line-height: 1.5; max-width: 480px;
  min-height: 2.4em;
}
.ch04-sort-feedback.ch04-ok  { color: var(--ok); }
.ch04-sort-feedback.ch04-no  { color: var(--err); }
.ch04-sort-done {
  font-family: 'Fraunces', Georgia, serif; font-size: 1.2rem; color: var(--accent-dark);
}
.ch04-pill-page, .ch04-pill-ticket {
  font-family: var(--mono); font-size: 0.72rem; font-weight: 700;
  padding: 0.12rem 0.5rem; border-radius: 999px;
}
.ch04-pill-page   { color: #fff; background: var(--accent-secondary); }
.ch04-pill-ticket { color: var(--accent-dark); background: var(--accent-light); }

/* === Widget 2 · Threshold Tuner readouts === */
.ch04-tuner-readrow {
  display: flex; flex-wrap: wrap; gap: 0.5rem; margin-top: 0.85rem;
}
.ch04-tuner-stat {
  flex: 1; min-width: 120px;
  background: var(--code-bg); border: 1px solid var(--code-border);
  border-radius: 8px; padding: 0.6rem 0.7rem;
}
.ch04-tuner-stat .k {
  font-size: 0.66rem; text-transform: uppercase; letter-spacing: 0.07em; color: var(--text-muted);
}
.ch04-tuner-stat .v {
  font-family: var(--mono); font-size: 1.05rem; font-weight: 600; color: var(--accent-dark);
}
.ch04-tuner-stat.ch04-bad .v { color: var(--accent-secondary); }
.ch04-verdict {
  margin-top: 0.7rem; font-size: 0.88rem; line-height: 1.5;
  padding: 0.7rem 0.85rem; border-radius: 8px;
  background: var(--accent-light); border: 1px solid #c7dde6; color: var(--accent-dark);
}
.ch04-verdict.ch04-verdict-bad {
  background: var(--accent-secondary-light); border-color: #eccab3; color: #97502b;
}

/* === Widget 3 · Probe vs X-ray === */
.ch04-px-grid {
  display: grid; grid-template-columns: 1fr 1fr; gap: 0.6rem; margin-top: 0.85rem;
}
.ch04-px-panel {
  background: var(--code-bg); border: 1px solid var(--code-border);
  border-radius: 8px; padding: 0.7rem 0.8rem;
}
.ch04-px-panel.ch04-off { opacity: 0.4; }
.ch04-px-panel .ch04-px-head {
  display: flex; align-items: center; justify-content: space-between;
  font-size: 0.72rem; font-weight: 600; text-transform: uppercase; letter-spacing: 0.06em;
  color: var(--text-muted); margin-bottom: 0.5rem;
}
.ch04-px-toggle {
  font: inherit; font-family: var(--mono); font-size: 0.66rem;
  border: 1px solid var(--code-border); background: var(--bg-card); color: var(--text-muted);
  border-radius: 999px; padding: 0.1rem 0.5rem; cursor: pointer;
}
.ch04-px-toggle.ch04-on { background: var(--accent); color: #fff; border-color: var(--accent); }
.ch04-probe-pill {
  display: inline-flex; align-items: center; gap: 0.35rem;
  font-family: var(--mono); font-size: 0.82rem; font-weight: 600;
  padding: 0.35rem 0.7rem; border-radius: 999px;
}
.ch04-probe-pill.ch04-pass { color: var(--ok);  background: var(--ok-light); }
.ch04-probe-pill.ch04-fail { color: var(--err); background: var(--err-light); }
.ch04-probe-note { font-size: 0.78rem; color: var(--text-muted); margin-top: 0.45rem; }
.ch04-xray-row {
  display: flex; align-items: center; gap: 0.5rem; margin-bottom: 0.35rem;
}
.ch04-xray-row .ch04-xray-name {
  font-family: var(--mono); font-size: 0.72rem; width: 46px; flex-shrink: 0; color: var(--text-muted);
}
.ch04-xray-bar {
  flex: 1; height: 9px; border-radius: 999px; background: var(--code-bg-soft); overflow: hidden;
}
.ch04-xray-fill {
  height: 100%; border-radius: 999px; background: var(--accent);
  transition: width 0.3s ease-out, background 0.3s ease-out;
}
.ch04-xray-fill.ch04-hot { background: var(--accent-secondary); }
.ch04-xray-row .ch04-xray-val {
  font-family: var(--mono); font-size: 0.7rem; width: 36px; text-align: right; color: var(--text-muted);
}
@media (max-width: 560px) { .ch04-px-grid { grid-template-columns: 1fr; } }


/* ===== ch05 widget styles ===== */
/* ============================================================
   Chapter 5 — Release Engineering · chapter-specific styles
   All classes prefixed ch05- · light code surfaces only.
   ============================================================ */

/* === Change-cause grid (section 1) === */
.ch05-causes {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 0.7rem;
  margin: 1.4rem 0 0.4rem;
}
.ch05-cause {
  background: var(--code-bg); border: 1px solid var(--code-border);
  border-radius: 8px; padding: 0.8rem 0.9rem; text-align: center;
}
.ch05-cause.ch05-cause-big {
  border-color: var(--accent-secondary);
  box-shadow: inset 0 3px 0 var(--accent-secondary);
}
.ch05-cause .ch05-cause-pct {
  font-family: var(--mono); font-size: 1.5rem; font-weight: 700; color: var(--accent-dark);
}
.ch05-cause.ch05-cause-big .ch05-cause-pct { color: var(--accent-secondary); }
.ch05-cause .ch05-cause-l {
  font-size: 0.8rem; color: var(--text-muted); margin-top: 0.15rem;
}
@media (max-width: 560px) { .ch05-causes { grid-template-columns: 1fr; } }

/* === Widget 1 · Blast Radius === */
.ch05-blast-grid-wrap { background: var(--bg-sunken); border-radius: 0.5rem; padding: 0.65rem; }
.ch05-blast-stats {
  display: flex; flex-wrap: wrap; gap: 0.5rem; margin-top: 0.85rem;
}
.ch05-blast-stat {
  flex: 1; min-width: 150px;
  background: var(--code-bg); border: 1px solid var(--code-border);
  border-radius: 8px; padding: 0.7rem 0.8rem;
}
.ch05-blast-stat.ch05-blast-bad { border-color: var(--accent-secondary); }
.ch05-blast-stat .k {
  font-size: 0.66rem; text-transform: uppercase; letter-spacing: 0.07em; color: var(--text-muted);
}
.ch05-blast-stat .v {
  font-family: var(--mono); font-size: 1rem; font-weight: 600; color: var(--accent-dark);
}
.ch05-blast-stat.ch05-blast-bad .v { color: var(--accent-secondary); }
.ch05-blast-stat .v small { font-size: 0.72rem; font-weight: 500; color: var(--text-muted); }

/* === Widget 2 · The Rollout Runner === */
.ch05-runner-track {
  display: flex; gap: 0.4rem; margin: 0.2rem 0 0.3rem;
}
.ch05-stage {
  flex: 1; position: relative;
  background: var(--code-bg); border: 1px solid var(--code-border);
  border-radius: 8px; padding: 0.7rem 0.5rem 0.6rem; text-align: center;
  overflow: hidden;
  transition: border-color 0.2s, box-shadow 0.2s;
}
.ch05-stage .ch05-stage-fill {
  position: absolute; left: 0; bottom: 0; right: 0; height: 0%;
  background: var(--accent-light);
  transition: height 0.45s ease-out;
  z-index: 0;
}
.ch05-stage.ch05-on .ch05-stage-fill { height: 100%; }
.ch05-stage .ch05-stage-pct,
.ch05-stage .ch05-stage-status { position: relative; z-index: 1; }
.ch05-stage .ch05-stage-pct {
  font-family: var(--mono); font-size: 1.15rem; font-weight: 700; color: var(--accent-dark);
}
.ch05-stage .ch05-stage-status {
  font-size: 0.66rem; text-transform: uppercase; letter-spacing: 0.06em;
  color: var(--text-muted); margin-top: 0.2rem; min-height: 1.1em;
}
.ch05-stage.ch05-pass { border-color: var(--ok); }
.ch05-stage.ch05-pass .ch05-stage-fill { background: var(--ok-light); }
.ch05-stage.ch05-pass .ch05-stage-status { color: var(--ok); }
.ch05-stage.ch05-fail { border-color: var(--accent-secondary); }
.ch05-stage.ch05-fail .ch05-stage-fill { background: var(--accent-secondary-light); }
.ch05-stage.ch05-fail .ch05-stage-status { color: var(--accent-secondary); }
.ch05-stage.ch05-fail.ch05-flash { animation: ch05-flash 0.35s ease-out 3; }
@keyframes ch05-flash {
  0%, 100% { box-shadow: 0 0 0 0 var(--accent-secondary-light); }
  50% { box-shadow: 0 0 0 4px var(--accent-secondary-light); }
}
.ch05-gate {
  align-self: center; flex: 0 0 auto;
  font-family: var(--mono); font-size: 0.8rem; color: var(--code-border);
  transition: color 0.2s;
}
.ch05-gate.ch05-gate-pass { color: var(--ok); }
.ch05-gate.ch05-gate-fail { color: var(--accent-secondary); }
.ch05-gate.ch05-gate-off { color: var(--text-muted); opacity: 0.4; }
.ch05-runner-verdict {
  margin-top: 0.7rem; font-size: 0.88rem; line-height: 1.5;
  padding: 0.7rem 0.85rem; border-radius: 8px; min-height: 1.2em;
  background: var(--code-bg); border: 1px solid var(--code-border); color: var(--text-muted);
}
.ch05-runner-verdict.ch05-ok  { background: var(--ok-light); border-color: #bfe4cb; color: #1b5e2e; }
.ch05-runner-verdict.ch05-bad { background: var(--accent-secondary-light); border-color: #eccab3; color: #97502b; }
.ch05-toggle {
  font: inherit; font-family: var(--mono); font-size: 0.74rem;
  border: 1px solid var(--code-border); background: var(--bg-card); color: var(--text-muted);
  border-radius: 999px; padding: 0.25rem 0.65rem; cursor: pointer;
  display: inline-flex; align-items: center; gap: 0.35rem;
  transition: all 0.15s ease-out;
}
.ch05-toggle:hover { border-color: var(--accent); color: var(--accent-dark); }
.ch05-toggle.ch05-on { background: var(--accent-secondary); color: #fff; border-color: var(--accent-secondary); }

/* === Widget 3 · Batch Size Bisector === */
.ch05-bisect-stats {
  display: flex; flex-wrap: wrap; gap: 0.5rem; margin-top: 0.85rem;
}
.ch05-bisect-stat {
  flex: 1; min-width: 130px;
  background: var(--code-bg); border: 1px solid var(--code-border);
  border-radius: 8px; padding: 0.6rem 0.7rem;
}
.ch05-bisect-stat .k {
  font-size: 0.66rem; text-transform: uppercase; letter-spacing: 0.07em; color: var(--text-muted);
}
.ch05-bisect-stat .v {
  font-family: var(--mono); font-size: 1.05rem; font-weight: 600; color: var(--accent-dark);
}
.ch05-bisect-stat.ch05-hot .v { color: var(--accent-secondary); }
.ch05-bisect-lesson {
  margin-top: 0.7rem; font-size: 0.9rem; line-height: 1.5;
  padding: 0.7rem 0.85rem; border-radius: 8px;
  background: var(--accent-light); border: 1px solid #c7dde6; color: var(--accent-dark);
}
.ch05-bisect-lesson.ch05-hot {
  background: var(--accent-secondary-light); border-color: #eccab3; color: #97502b;
}

/* === Flag-life note (section 7) === */
.ch05-note {
  display: flex; gap: 0.6rem; align-items: flex-start;
  font-size: 0.86rem; color: var(--text-muted);
  margin: 0.4rem 0 0;
}


/* ===== ch06 widget styles ===== */
/* ============================================================
   Chapter 6 — On-Call · chapter-specific styles
   All classes prefixed ch06- · light code surfaces only.
   ============================================================ */

/* === Two-number callout strip (section 2) === */
.ch06-rules {
  display: grid; grid-template-columns: 1fr 1fr; gap: 0.7rem;
  margin: 1.4rem 0 0.4rem;
}
.ch06-rule {
  background: var(--code-bg); border: 1px solid var(--code-border);
  border-radius: 8px; padding: 0.85rem 0.95rem;
  border-left: 3px solid var(--accent);
}
.ch06-rule .ch06-rule-num {
  font-family: var(--mono); font-size: 1.6rem; font-weight: 700; color: var(--accent-dark);
  line-height: 1.1;
}
.ch06-rule .ch06-rule-l {
  font-size: 0.82rem; color: var(--text-muted); margin-top: 0.2rem;
}
@media (max-width: 560px) { .ch06-rules { grid-template-columns: 1fr; } }

/* === Widget 1 · Rotation Calculator === */
.ch06-rot-wrap { background: var(--bg-sunken); border-radius: 0.5rem; padding: 0.65rem; }
.ch06-sites-toggle { display: inline-flex; gap: 0; border: 1px solid var(--code-border); border-radius: 8px; overflow: hidden; }
.ch06-sites-toggle button {
  font: inherit; font-family: var(--mono); font-size: 0.8rem;
  border: none; background: var(--bg-card); color: var(--text-muted);
  padding: 0.35rem 0.7rem; cursor: pointer; transition: all 0.15s ease-out;
}
.ch06-sites-toggle button + button { border-left: 1px solid var(--code-border); }
.ch06-sites-toggle button.ch06-on { background: var(--accent); color: #fff; }

.ch06-rot-stats { display: flex; flex-wrap: wrap; gap: 0.5rem; margin-top: 0.85rem; }
.ch06-rot-stat {
  flex: 1; min-width: 150px;
  background: var(--code-bg); border: 1px solid var(--code-border);
  border-radius: 8px; padding: 0.7rem 0.8rem;
}
.ch06-rot-stat .k {
  font-size: 0.66rem; text-transform: uppercase; letter-spacing: 0.07em; color: var(--text-muted);
}
.ch06-rot-stat .v {
  font-family: var(--mono); font-size: 1.1rem; font-weight: 700; color: var(--accent-dark);
}
.ch06-rot-stat .v small { font-size: 0.72rem; font-weight: 500; color: var(--text-muted); }
.ch06-rot-stat.ch06-over { border-color: var(--accent-secondary); }
.ch06-rot-stat.ch06-over .v { color: var(--accent-secondary); }

.ch06-verdict {
  margin-top: 0.7rem;
  display: inline-flex; align-items: center; gap: 0.45rem;
  font-size: 0.85rem; font-weight: 600;
  padding: 0.4rem 0.85rem; border-radius: 999px;
  border: 1px solid transparent;
}
.ch06-verdict::before { content: ''; width: 9px; height: 9px; border-radius: 50%; background: currentColor; }
.ch06-verdict.ch06-sus  { background: var(--accent-light); color: var(--accent-dark); border-color: #c7dde6; }
.ch06-verdict.ch06-str  { background: var(--warn-light); color: var(--warn); border-color: #f3dcb6; }
.ch06-verdict.ch06-burn { background: var(--accent-secondary-light); color: #97502b; border-color: #eccab3; }

/* === Widget 2 · First Move === */
.ch06-page {
  background: var(--code-bg); border: 1px solid var(--code-border);
  border-left: 3px solid var(--accent-secondary);
  border-radius: 8px; padding: 0.85rem 1rem; margin-bottom: 0.85rem;
}
.ch06-page .ch06-page-top {
  display: flex; justify-content: space-between; align-items: baseline; gap: 0.6rem;
  font-family: var(--mono); font-size: 0.72rem; text-transform: uppercase;
  letter-spacing: 0.07em; color: var(--text-muted); margin-bottom: 0.3rem;
}
.ch06-page .ch06-page-sev { color: var(--accent-secondary); font-weight: 700; }
.ch06-page .ch06-page-body { font-family: var(--mono); font-size: 0.9rem; color: var(--code-fg); line-height: 1.5; }

.ch06-move {
  display: block; width: 100%; text-align: left;
  font: inherit; font-size: 0.9rem;
  background: var(--bg-card); border: 1px solid var(--border);
  border-radius: 8px; padding: 0.6rem 0.85rem; margin-bottom: 0.5rem;
  cursor: pointer; transition: all 0.12s ease-out;
  display: flex; align-items: center; gap: 0.6rem;
}
.ch06-move:hover:not(.ch06-locked) { border-color: var(--accent); background: var(--accent-light); }
.ch06-move .ch06-mk { width: 18px; flex-shrink: 0; font-weight: 700; font-family: var(--mono); color: var(--accent); }
.ch06-move.ch06-right { border-color: var(--ok); background: var(--ok-light); color: #1b5e2e; }
.ch06-move.ch06-wrong { border-color: var(--err); background: var(--err-light); color: #b91c1c; }
.ch06-move.ch06-locked { cursor: default; }
.ch06-fm-fb {
  font-size: 0.88rem; margin-top: 0.5rem; line-height: 1.5; min-height: 1.2em;
  padding: 0; color: var(--text-muted);
}
.ch06-fm-fb.ch06-show.ch06-ok { color: var(--ok); }
.ch06-fm-fb.ch06-show.ch06-no { color: var(--err); }

/* === Widget 3 · Wheel of Misfortune === */
.ch06-wheel-wrap { background: var(--bg-sunken); border-radius: 0.5rem; padding: 0.65rem; text-align: center; }
.ch06-wheel-svg { width: 100%; max-width: 360px; height: auto; display: block; margin: 0 auto; }
.ch06-steps { margin-top: 0.85rem; }
.ch06-step {
  display: flex; gap: 0.7rem; align-items: flex-start;
  background: var(--code-bg); border: 1px solid var(--code-border);
  border-radius: 8px; padding: 0.7rem 0.85rem; margin-bottom: 0.5rem;
  animation: ch06-stepin 0.3s ease-out both;
}
@keyframes ch06-stepin { from { opacity: 0; transform: translateY(6px); } to { opacity: 1; transform: none; } }
.ch06-step .ch06-step-n {
  flex-shrink: 0; width: 22px; height: 22px; border-radius: 50%;
  background: var(--accent); color: #fff; font-family: var(--mono); font-size: 0.78rem; font-weight: 700;
  display: grid; place-items: center;
}
.ch06-step .ch06-step-txt { font-size: 0.9rem; line-height: 1.5; }
.ch06-step .ch06-tag {
  font-family: var(--mono); font-size: 0.62rem; font-weight: 700; text-transform: uppercase;
  letter-spacing: 0.06em; padding: 0.1em 0.45em; border-radius: 4px; margin-left: 0.4em;
  vertical-align: 0.08em; white-space: nowrap;
}
.ch06-step .ch06-tag.ch06-mit { background: var(--accent-light); color: var(--accent-dark); }
.ch06-step .ch06-tag.ch06-diag { background: var(--accent-secondary-light); color: #97502b; }
.ch06-wheel-landed {
  font-family: var(--mono); font-size: 0.85rem; font-weight: 700; color: var(--accent-dark);
  margin-top: 0.6rem; min-height: 1.2em;
}


/* ===== ch07 widget styles ===== */
/* ============================================================
   Chapter 7 — Blameless Postmortems · chapter-specific styles
   All classes prefixed ch07- · light code surfaces only.
   ============================================================ */

/* === Anatomy strip (section 4) === */
.ch07-anatomy {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 0.65rem;
  margin: 1.4rem 0 0.4rem;
}
.ch07-part {
  background: var(--code-bg); border: 1px solid var(--code-border);
  border-radius: 8px; padding: 0.8rem 0.9rem;
  border-left: 3px solid var(--accent);
}
.ch07-part .ch07-part-k {
  font-family: var(--mono); font-size: 0.72rem; text-transform: uppercase;
  letter-spacing: 0.06em; color: var(--accent-dark); font-weight: 700;
}
.ch07-part .ch07-part-v { font-size: 0.86rem; color: var(--text-muted); margin-top: 0.25rem; }
@media (max-width: 640px) { .ch07-anatomy { grid-template-columns: 1fr; } }

/* === Trigger vs root cause inline two-up === */
.ch07-gun {
  display: grid; grid-template-columns: 1fr 1fr; gap: 0.7rem; margin: 1.3rem 0;
}
.ch07-gun > div {
  border-radius: 8px; padding: 0.8rem 0.95rem; font-size: 0.9rem;
  border: 1px solid var(--code-border);
}
.ch07-gun .ch07-trigger { background: var(--accent-secondary-light); border-left: 3px solid var(--accent-secondary); }
.ch07-gun .ch07-loaded { background: var(--accent-light); border-left: 3px solid var(--accent); }
.ch07-gun b { display: block; margin-bottom: 0.2rem; font-size: 0.78rem; text-transform: uppercase; letter-spacing: 0.06em; }
.ch07-gun .ch07-trigger b { color: var(--accent-secondary); }
.ch07-gun .ch07-loaded b { color: var(--accent-dark); }
@media (max-width: 560px) { .ch07-gun { grid-template-columns: 1fr; } }

/* === Widget 1 · The Blameless Rewriter === */
.ch07-rw-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 0.7rem; }
@media (max-width: 560px) { .ch07-rw-grid { grid-template-columns: 1fr; } }
.ch07-card {
  background: transparent; border: none; padding: 0;
  perspective: 900px; cursor: pointer; min-height: 118px;
  font: inherit; text-align: left;
}
.ch07-card-inner {
  position: relative; width: 100%; height: 100%; min-height: 118px;
  transition: transform 0.5s cubic-bezier(.2,.7,.2,1);
  transform-style: preserve-3d;
}
.ch07-card.ch07-flipped .ch07-card-inner { transform: rotateY(180deg); }
.ch07-face {
  position: absolute; inset: 0;
  -webkit-backface-visibility: hidden; backface-visibility: hidden;
  border-radius: 8px; padding: 0.85rem 0.95rem;
  display: flex; flex-direction: column; gap: 0.35rem;
  border: 1px solid var(--code-border);
}
.ch07-face .ch07-tag {
  font-family: var(--mono); font-size: 0.66rem; text-transform: uppercase;
  letter-spacing: 0.07em; font-weight: 700;
}
.ch07-face .ch07-line { font-size: 0.9rem; line-height: 1.5; }
.ch07-face-front { background: var(--accent-secondary-light); border-left: 3px solid var(--accent-secondary); }
.ch07-face-front .ch07-tag { color: var(--accent-secondary); }
.ch07-face-back {
  background: var(--accent-light); border-left: 3px solid var(--accent);
  transform: rotateY(180deg);
}
.ch07-face-back .ch07-tag { color: var(--accent-dark); }
.ch07-face .ch07-flip-hint { font-size: 0.68rem; color: var(--text-muted); margin-top: auto; font-family: var(--mono); }

/* === Widget 2 · Swiss Cheese Machine === */
.ch07-cheese-wrap { background: var(--bg-sunken); border-radius: 0.5rem; padding: 0.5rem; }
.ch07-layer-toggles { display: flex; flex-wrap: wrap; gap: 0.4rem; }
.ch07-lt {
  font: inherit; font-family: var(--mono); font-size: 0.78rem;
  border: 1px solid var(--code-border); background: var(--bg-card);
  color: var(--text-muted); border-radius: 8px;
  padding: 0.35rem 0.7rem; cursor: pointer; transition: all 0.15s ease-out;
  display: inline-flex; align-items: center; gap: 0.4rem;
}
.ch07-lt .ch07-led { width: 8px; height: 8px; border-radius: 50%; background: var(--accent); transition: background 0.15s; }
.ch07-lt.ch07-off { color: var(--text-muted); opacity: 0.6; }
.ch07-lt.ch07-off .ch07-led { background: var(--code-border); }
.ch07-lt:not(.ch07-off) { color: var(--accent-dark); border-color: var(--accent); }

/* === Widget 3 · Hindsight Goggles === */
.ch07-mode-toggle { display: inline-flex; gap: 0; border: 1px solid var(--code-border); border-radius: 8px; overflow: hidden; }
.ch07-mode-toggle button {
  font: inherit; font-family: var(--mono); font-size: 0.78rem;
  border: none; background: var(--bg-card); color: var(--text-muted);
  padding: 0.4rem 0.8rem; cursor: pointer; transition: all 0.15s ease-out;
}
.ch07-mode-toggle button + button { border-left: 1px solid var(--code-border); }
.ch07-mode-toggle button.ch07-on { background: var(--accent); color: #fff; }
.ch07-mode-toggle button.ch07-on.ch07-danger { background: var(--accent-secondary); }

.ch07-timeline { margin-top: 0.85rem; display: flex; flex-direction: column; gap: 0.5rem; }
.ch07-tl-row {
  display: grid; grid-template-columns: 64px 1fr; gap: 0.7rem; align-items: start;
  background: var(--code-bg); border: 1px solid var(--code-border);
  border-radius: 8px; padding: 0.6rem 0.75rem;
}
.ch07-tl-row .ch07-ts { font-family: var(--mono); font-size: 0.82rem; font-weight: 700; color: var(--accent-dark); }
.ch07-tl-row .ch07-ev { font-size: 0.88rem; line-height: 1.5; }
.ch07-tl-row .ch07-note {
  font-size: 0.78rem; margin-top: 0.3rem; padding: 0.25rem 0.5rem;
  border-radius: 6px; font-family: var(--mono);
  background: var(--accent-light); color: var(--accent-dark);
  border-left: 2px solid var(--accent);
}
.ch07-tl-row.ch07-hind .ch07-note {
  background: var(--err-light); color: var(--err);
  border-left-color: var(--err);
}
.ch07-tl-readout {
  margin-top: 0.85rem; padding: 0.7rem 0.9rem; border-radius: 8px;
  font-size: 0.88rem; line-height: 1.55;
  background: var(--accent-light); border-left: 3px solid var(--accent); color: var(--accent-dark);
}
.ch07-tl-readout.ch07-hind { background: var(--err-light); border-left-color: var(--err); color: var(--err); }


/* ===== ch08 widget styles ===== */
/* ============================================================
   Chapter 8 — Handling Overload · chapter-specific styles
   All classes prefixed ch08- · light code surfaces only.
   ============================================================ */

/* === Generic readout grid (reused across widgets) === */
.ch08-readrow { display: flex; flex-wrap: wrap; gap: 0.5rem; margin-top: 0.85rem; }
.ch08-stat {
  flex: 1; min-width: 120px;
  background: var(--code-bg); border: 1px solid var(--code-border);
  border-radius: 8px; padding: 0.6rem 0.7rem;
}
.ch08-stat .k { font-size: 0.68rem; text-transform: uppercase; letter-spacing: 0.07em; color: var(--text-muted); }
.ch08-stat .v { font-family: var(--mono); font-size: 1.05rem; font-weight: 600; color: var(--accent-dark); }
.ch08-stat.ch08-bad .v { color: var(--accent-secondary); }

/* === Verdict line (under widgets) === */
.ch08-verdict {
  margin-top: 0.85rem; padding: 0.65rem 0.9rem; border-radius: 8px;
  font-size: 0.9rem; line-height: 1.5;
  background: var(--accent-light); border-left: 3px solid var(--accent); color: var(--accent-dark);
}
.ch08-verdict.ch08-warm { background: var(--warn-light); border-left-color: var(--warn); color: var(--warn); }
.ch08-verdict.ch08-cliff { background: var(--err-light); border-left-color: var(--err); color: var(--err); }

/* === Radio chips (mode selectors) === */
.ch08-chips { display: inline-flex; gap: 0; border: 1px solid var(--code-border); border-radius: 8px; overflow: hidden; flex-wrap: wrap; }
.ch08-chips button {
  font: inherit; font-family: var(--mono); font-size: 0.78rem;
  border: none; background: var(--bg-card); color: var(--text-muted);
  padding: 0.42rem 0.8rem; cursor: pointer; transition: all 0.15s ease-out;
}
.ch08-chips button + button { border-left: 1px solid var(--code-border); }
.ch08-chips button.ch08-on { background: var(--accent); color: #fff; }

/* === The hockey stick · queue dots strip === */
.ch08-queue {
  margin-top: 0.7rem;
  background: var(--code-bg); border: 1px solid var(--code-border);
  border-radius: 8px; padding: 0.55rem 0.7rem;
}
.ch08-queue .ch08-queue-lab {
  font-size: 0.68rem; text-transform: uppercase; letter-spacing: 0.07em;
  color: var(--text-muted); margin-bottom: 0.35rem;
}
.ch08-queue svg { width: 100%; height: auto; display: block; }

/* === Domino cluster · server bars === */
.ch08-cluster {
  display: grid; grid-template-columns: repeat(5, 1fr); gap: 0.55rem;
  background: var(--bg-sunken); border-radius: 0.5rem; padding: 0.7rem;
}
.ch08-srv {
  background: var(--code-bg); border: 1px solid var(--code-border);
  border-radius: 8px; padding: 0.5rem; display: flex; flex-direction: column; gap: 0.4rem;
}
.ch08-srv .ch08-srv-name {
  font-family: var(--mono); font-size: 0.7rem; font-weight: 700;
  color: var(--accent-dark); display: flex; justify-content: space-between; align-items: baseline;
}
.ch08-srv .ch08-srv-pct { color: var(--text-muted); font-weight: 500; }
.ch08-srv .ch08-bar {
  position: relative; height: 92px; border-radius: 6px;
  background: var(--bg-card); border: 1px solid var(--code-border);
  overflow: hidden; display: flex; align-items: flex-end;
}
.ch08-srv .ch08-fill {
  width: 100%; background: var(--accent); transition: height 0.45s ease-out, background 0.3s;
  border-radius: 0 0 5px 5px;
}
.ch08-srv .ch08-cap-line {
  position: absolute; left: 0; right: 0; height: 0; border-top: 2px dashed var(--accent-secondary);
}
.ch08-srv.ch08-warm .ch08-fill { background: var(--warn); }
.ch08-srv.ch08-shedding .ch08-fill { background: var(--warn); }
.ch08-srv.ch08-dead { opacity: 0.85; }
.ch08-srv.ch08-dead .ch08-fill { background: var(--accent-secondary); height: 100% !important; }
.ch08-srv.ch08-dead .ch08-srv-name { color: var(--accent-secondary); }
.ch08-srv .ch08-drops {
  font-family: var(--mono); font-size: 0.62rem; color: var(--accent-secondary);
  min-height: 1em; letter-spacing: 0.04em; word-break: break-all;
}
@media (max-width: 560px) {
  .ch08-cluster { grid-template-columns: repeat(5, 1fr); gap: 0.3rem; padding: 0.45rem; }
  .ch08-srv { padding: 0.35rem; }
  .ch08-srv .ch08-bar { height: 70px; }
}

/* === Degradation ladder (section 4) === */
.ch08-ladder { display: flex; flex-direction: column; gap: 0.5rem; margin: 1.3rem 0 0.4rem; }
.ch08-rung {
  display: grid; grid-template-columns: auto 1fr; gap: 0.7rem; align-items: center;
  background: var(--code-bg); border: 1px solid var(--code-border);
  border-radius: 8px; padding: 0.6rem 0.8rem; border-left: 3px solid var(--accent);
}
.ch08-rung .ch08-rung-ic { font-size: 1.2rem; }
.ch08-rung .ch08-rung-t { font-weight: 600; font-size: 0.92rem; }
.ch08-rung .ch08-rung-d { font-size: 0.82rem; color: var(--text-muted); }
.ch08-rung.ch08-rung-cheap { border-left-color: var(--accent-secondary); }


/* ===== ch09 widget styles ===== */
/* ============================================================
   Chapter 9 — Data Integrity
   Chapter-specific rules. All classes prefixed `ch09-`.
   Shared classes (.widget, .controls, .readout, .btn, .quiz-*,
   .code-card, etc.) come from style.css — do not duplicate them.
   ============================================================ */

/* shared readout grid used by the widgets */
.ch09-readrow {
  display: flex; flex-wrap: wrap; gap: 0.5rem; margin-top: 0.85rem;
}
.ch09-stat {
  flex: 1; min-width: 120px;
  background: var(--code-bg); border: 1px solid var(--code-border);
  border-radius: 8px; padding: 0.6rem 0.7rem;
}
.ch09-stat .k {
  font-size: 0.68rem; text-transform: uppercase; letter-spacing: 0.07em;
  color: var(--text-muted);
}
.ch09-stat .v {
  font-family: var(--mono); font-size: 1.05rem; font-weight: 600;
  color: var(--accent-dark);
}
.ch09-stat.bad  { background: var(--err-light); border-color: #f3c9c9; }
.ch09-stat.bad  .v { color: var(--err); }
.ch09-stat.good { background: var(--ok-light); border-color: #c6e4d0; }
.ch09-stat.good .v { color: var(--ok); }
.ch09-stat.warn { background: var(--accent-secondary-light); border-color: #ecc6ad; }
.ch09-stat.warn .v { color: var(--accent-secondary); }

/* a verdict line under a widget — full-width sentence in the chapter voice */
.ch09-verdict {
  margin-top: 0.7rem;
  font-size: 0.9rem; line-height: 1.5;
  color: var(--text-muted);
  background: var(--bg-sunken);
  border: 1px solid var(--border);
  border-left: 3px solid var(--accent);
  border-radius: 8px;
  padding: 0.6rem 0.8rem;
}
.ch09-verdict.bad  { border-left-color: var(--err); background: var(--err-light); color: #8a3030; }
.ch09-verdict.good { border-left-color: var(--ok);  background: var(--ok-light); color: #1b5e2e; }
.ch09-verdict.warn { border-left-color: var(--accent-secondary); background: var(--accent-secondary-light); color: #94522c; }
.ch09-verdict strong { color: inherit; }

/* === Widget 1 — replication vs backup: two-panel layout === */
.ch09-twopanel {
  display: grid; grid-template-columns: 1fr 1fr; gap: 0.6rem;
}
@media (max-width: 560px) { .ch09-twopanel { grid-template-columns: 1fr; } }
.ch09-panel {
  background: var(--bg-sunken); border: 1px solid var(--border);
  border-radius: 0.5rem; padding: 0.5rem;
}
.ch09-panel .ch09-panel-head {
  font-size: 0.72rem; font-weight: 600; text-transform: uppercase; letter-spacing: 0.06em;
  color: var(--text-muted); margin: 0.1rem 0 0.35rem 0.15rem;
  display: flex; align-items: center; gap: 0.4rem;
}
.ch09-panel .ch09-panel-head .ch09-tag {
  font-family: var(--mono); font-size: 0.62rem; font-weight: 700;
  padding: 0.05rem 0.4rem; border-radius: 999px;
  background: var(--accent-light); color: var(--accent-dark);
  letter-spacing: 0;
}
.ch09-panel .ch09-panel-head .ch09-tag.rust {
  background: var(--accent-secondary-light); color: #94522c;
}

/* === Widget 3 — posture chip groups === */
.ch09-chipgroup {
  display: flex; flex-wrap: wrap; gap: 0.4rem; align-items: center;
  margin-top: 0.7rem;
}
.ch09-chipgroup > .ch09-label {
  font-size: 0.72rem; font-weight: 600; text-transform: uppercase; letter-spacing: 0.06em;
  color: var(--text-muted); margin-right: 0.2rem; min-width: 86px;
}
.ch09-chip {
  font: inherit; font-size: 0.8rem; font-weight: 500;
  border: 1px solid var(--border); background: var(--bg-card);
  color: var(--text-muted); border-radius: 999px;
  padding: 0.32rem 0.7rem; cursor: pointer;
  transition: all 0.15s ease-out;
}
.ch09-chip:hover { border-color: var(--accent); color: var(--accent-dark); }
.ch09-chip.active {
  background: var(--accent); color: #fff; border-color: var(--accent);
}

/* toggle row used in the corruption clock */
.ch09-toggles { display: flex; flex-wrap: wrap; gap: 0.5rem; margin-top: 0.85rem; align-items: center; }


/* ===== ch10 widget styles ===== */
/* === CH.10 · Launches & Capacity === */

/* --- N+2 Planner --- */
.ch10-fleet-readrow { display: flex; flex-wrap: wrap; gap: 0.5rem; margin-top: 0.85rem; }
.ch10-fleet-stat {
  flex: 1; min-width: 120px;
  background: var(--code-bg); border: 1px solid var(--code-border);
  border-radius: 8px; padding: 0.6rem 0.7rem;
}
.ch10-fleet-stat .k { font-size: 0.68rem; text-transform: uppercase; letter-spacing: 0.07em; color: var(--text-muted); }
.ch10-fleet-stat .v { font-family: var(--mono); font-size: 1.05rem; font-weight: 600; color: var(--accent-dark); }

.ch10-verdict {
  display: inline-flex; align-items: center; gap: 0.45rem;
  font-size: 0.85rem; font-weight: 600;
  padding: 0.4rem 0.85rem; border-radius: 999px;
  border: 1px solid transparent;
}
.ch10-verdict.good   { background: var(--accent-light); color: var(--accent-dark); border-color: #c7dde6; }
.ch10-verdict.warn   { background: var(--warn-light); color: var(--warn); border-color: #f3dcb6; }
.ch10-verdict.bad    { background: var(--accent-secondary-light); color: #b9623a; border-color: #eecbb4; }

/* toggle chips */
.ch10-toggle {
  font: inherit; font-size: 0.85rem; font-weight: 500;
  border: 1px solid var(--border); background: var(--bg-card);
  color: var(--text); border-radius: 8px;
  padding: 0.45rem 0.85rem; cursor: pointer;
  transition: all 0.15s ease-out;
  display: inline-flex; align-items: center; gap: 0.4rem;
}
.ch10-toggle:hover { border-color: var(--accent); color: var(--accent-dark); }
.ch10-toggle.on { background: var(--accent-secondary); color: #fff; border-color: var(--accent-secondary); }

/* --- Ramp Room --- */
.ch10-chips { display: flex; flex-wrap: wrap; gap: 0.5rem; }
.ch10-chip {
  font: inherit; font-size: 0.85rem; font-weight: 500;
  border: 1px solid var(--border); background: var(--bg-card);
  color: var(--text); border-radius: 999px;
  padding: 0.4rem 0.9rem; cursor: pointer;
  transition: all 0.15s ease-out;
}
.ch10-chip:hover { border-color: var(--accent); color: var(--accent-dark); }
.ch10-chip.active { background: var(--accent); color: #fff; border-color: var(--accent); }

.ch10-ramp-readrow { display: flex; flex-wrap: wrap; gap: 0.5rem; margin-top: 0.85rem; }
.ch10-ramp-stat {
  flex: 1; min-width: 130px;
  background: var(--code-bg); border: 1px solid var(--code-border);
  border-radius: 8px; padding: 0.6rem 0.7rem;
}
.ch10-ramp-stat .k { font-size: 0.68rem; text-transform: uppercase; letter-spacing: 0.07em; color: var(--text-muted); }
.ch10-ramp-stat .v { font-family: var(--mono); font-size: 1.05rem; font-weight: 600; color: var(--accent-dark); }
.ch10-ramp-verdict {
  margin-top: 0.85rem; font-size: 0.92rem; color: var(--text-muted);
  font-style: italic; min-height: 1.3em;
}
.ch10-ramp-verdict b { color: var(--accent-dark); font-style: normal; }

/* --- Launch Day Roulette --- */
.ch10-roulette-chips { display: flex; flex-wrap: wrap; gap: 0.5rem; margin-bottom: 0.5rem; }
.ch10-prep {
  font: inherit; font-size: 0.82rem; font-weight: 500;
  border: 1px solid var(--border); background: var(--bg-card);
  color: var(--text); border-radius: 8px;
  padding: 0.45rem 0.8rem; cursor: pointer;
  transition: all 0.15s ease-out;
  display: inline-flex; align-items: center; gap: 0.4rem;
}
.ch10-prep:hover:not(:disabled) { border-color: var(--accent); color: var(--accent-dark); }
.ch10-prep.picked { background: var(--accent-light); color: var(--accent-dark); border-color: var(--accent); }
.ch10-prep:disabled { opacity: 0.4; cursor: not-allowed; }
.ch10-budget-note { font-size: 0.8rem; color: var(--text-muted); margin: 0.2rem 0 0.4rem; }

.ch10-log {
  background: var(--code-bg); border: 1px solid var(--code-border);
  border-radius: 8px; padding: 0.75rem 0.9rem; margin-top: 0.85rem;
  font-family: var(--mono); font-size: 0.82rem; line-height: 1.6;
  min-height: 4em; color: var(--code-fg);
}
.ch10-log .line { margin-bottom: 0.3rem; display: flex; gap: 0.5rem; align-items: baseline; }
.ch10-log .line:last-child { margin-bottom: 0; }
.ch10-log .ok  { color: var(--ok); }
.ch10-log .no  { color: var(--err); }
.ch10-log .ev  { color: var(--text); }
.ch10-log .empty { color: var(--text-muted); font-style: italic; }

/* --- next-card finale (styles shared classes for this page only) --- */
.next-card.finale { background: linear-gradient(135deg, var(--accent-light), var(--accent-secondary-light)); }
.next-card.finale .big { font-size: 2.2rem; }
.next-card.finale .t2 { font-family: 'Fraunces', Georgia, serif; font-size: 1.35rem; }