@import url('https://fonts.googleapis.com/css2?family=Lora:ital,wght@0,400;0,600;1,400&family=JetBrains+Mono:wght@400;500&display=swap');

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --ink: #1a1814;
  --ink2: #4a4844;
  --ink3: #8a8880;
  --page: #faf8f4;
  --rule: #e8e4dc;
  --amber: #c47a1a;
  --amber-light: #fdf3e0;
  --red: #b83232;
  --red-light: #fdeaea;
  --teal: #1a7a5a;
  --teal-light: #e0f5ec;
  --blue: #1a4a8a;
  --blue-light: #e6eefc;
  --code-bg: #f0ede6;
  --max: 680px;
  --serif: 'Lora', Georgia, serif;
  --mono: 'JetBrains Mono', monospace;
}

html { scroll-padding-top: 56px; }
body {
  font-family: var(--serif);
  font-size: 18px;
  line-height: 1.75;
  color: var(--ink);
  background: var(--page);
  padding: 0 1rem 6rem;
}

/* Section nav chips — sticky scroll-spy */
.toc {
  position: sticky;
  top: 0;
  z-index: 10;
  margin: 0 -1rem 2rem;
  padding: 0.55rem 1rem;
  background: rgba(250, 248, 244, 0.92);
  backdrop-filter: saturate(140%) blur(8px);
  -webkit-backdrop-filter: saturate(140%) blur(8px);
  border-bottom: 1px solid var(--rule);
  overflow-x: auto;
  white-space: nowrap;
  scrollbar-width: none;
}
.toc::-webkit-scrollbar { display: none; }
.toc-chip {
  display: inline-block;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.04em;
  color: var(--ink3);
  text-decoration: none;
  padding: 4px 10px;
  margin-right: 6px;
  border: 1px solid var(--rule);
  border-radius: 14px;
  background: transparent;
  white-space: nowrap;
  transition: color 0.15s, background 0.15s, border-color 0.15s;
}
.toc-chip:hover { color: var(--ink); border-color: var(--ink3); }
.toc-chip.toc-active {
  color: var(--page);
  background: var(--ink);
  border-color: var(--ink);
}
.toc-back {
  color: var(--ink2);
  border-right: 1px solid var(--rule);
  margin-right: 10px;
  padding-right: 14px;
}
.toc-back:hover { color: var(--ink); }

.article {
  max-width: var(--max);
  margin: 0 auto;
}

header {
  padding: 4rem 0 2.5rem;
  border-bottom: 1px solid var(--rule);
  margin-bottom: 3rem;
}

.kicker {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ink3);
  margin-bottom: 1rem;
}

h1 {
  font-size: clamp(28px, 5vw, 42px);
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: -0.02em;
  margin-bottom: 1.25rem;
}

.lede {
  font-size: 20px;
  line-height: 1.6;
  color: var(--ink2);
  font-style: italic;
}

h2 {
  font-size: 22px;
  font-weight: 600;
  letter-spacing: -0.01em;
  margin: 3rem 0 1rem;
  padding-top: 2rem;
  border-top: 1px solid var(--rule);
}

p { margin-bottom: 1.25rem; }
p:last-child { margin-bottom: 0; }

strong { font-weight: 600; }
em { font-style: italic; }

code {
  font-family: var(--mono);
  font-size: 0.82em;
  background: var(--code-bg);
  padding: 1px 5px;
  border-radius: 3px;
  color: var(--ink);
}

pre {
  font-family: var(--mono);
  font-size: 14px;
  background: var(--code-bg);
  border-left: 3px solid var(--rule);
  padding: 1rem 1.25rem;
  margin: 1.5rem 0;
  overflow-x: auto;
  line-height: 1.6;
  color: var(--ink);
}

.callout {
  border-left: 3px solid var(--amber);
  background: var(--amber-light);
  padding: 1rem 1.25rem;
  margin: 2rem 0;
  border-radius: 0 6px 6px 0;
  font-size: 16px;
  color: var(--ink2);
}
.callout.danger {
  border-left-color: var(--red);
  background: var(--red-light);
}
.callout.success {
  border-left-color: var(--teal);
  background: var(--teal-light);
}

.diagram-wrap {
  margin: 2.5rem 0;
  border: 1px solid var(--rule);
  border-radius: 8px;
  overflow: hidden;
  background: white;
}
.diagram-wrap--single {
  max-width: 260px;
  margin-left: auto;
  margin-right: auto;
}
.diagram-wrap svg { display: block; width: 100%; }
.diagram-wrap canvas { max-width: 100%; height: auto; }
.diagram-caption {
  font-family: var(--mono);
  font-size: 12px;
  color: var(--ink3);
  padding: 0.6rem 1rem;
  border-top: 1px solid var(--rule);
  background: var(--code-bg);
}

/* sack-normal step widget */
.nf-widget { display: block; }
.nf-narr {
  font-size: 13px;
  line-height: 1.65;
  color: var(--ink2);
  margin-bottom: 12px;
  padding-left: 12px;
  border-left: 3px solid var(--rule);
  font-style: italic;
  font-family: var(--serif);
}
.nf-bar {
  display: flex;
  width: 100%;
  border-radius: 4px;
  overflow: hidden;
  border: 1px solid var(--rule);
  margin-bottom: 8px;
}
.nf-cell {
  flex: 1;
  height: 40px;
  display: flex;
  align-items: flex-end;
  justify-content: center;
  padding-bottom: 5px;
}
.nf-cell-num {
  font-size: 9px;
  font-family: var(--mono);
  line-height: 1;
  user-select: none;
}
.nf-cell-acked   { background: var(--rule);          color: var(--ink3); }
.nf-cell-flight  { background: rgba(26,74,138,0.13); color: var(--blue); }
.nf-cell-hole    { background: rgba(196,122,26,0.1); color: var(--amber); position: relative; overflow: hidden; }
.nf-cell-hole::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    linear-gradient(to bottom right, transparent calc(50% - 0.8px), rgba(196,122,26,0.5) calc(50% - 0.8px), rgba(196,122,26,0.5) calc(50% + 0.8px), transparent calc(50% + 0.8px)),
    linear-gradient(to bottom left,  transparent calc(50% - 0.8px), rgba(196,122,26,0.5) calc(50% - 0.8px), rgba(196,122,26,0.5) calc(50% + 0.8px), transparent calc(50% + 0.8px));
}
.nf-cell-unsent  { background: var(--code-bg);       color: #c0bdb5; }
.nf-legend {
  display: flex;
  gap: 1rem;
  margin-bottom: 12px;
}
.nf-leg {
  display: flex;
  align-items: center;
  gap: 5px;
  font-size: 11px;
  font-family: var(--mono);
  color: var(--ink3);
}
.nf-dot {
  display: inline-block;
  width: 8px;
  height: 8px;
  border-radius: 2px;
  flex-shrink: 0;
}
.nf-evt {
  font-size: 13px;
  line-height: 1.6;
  padding: 9px 12px;
  border-radius: 8px;
  margin-bottom: 10px;
  background: #f8f6f2;
  border: 1px solid var(--rule);
  color: var(--ink);
  font-family: var(--serif);
}
.nf-meta {
  font-size: 12px;
  font-family: var(--mono);
  color: var(--ink3);
  margin-bottom: 10px;
}
.nf-holes-label {
  font-size: 11px;
  font-family: var(--mono);
  color: var(--ink3);
  text-transform: uppercase;
  letter-spacing: .06em;
  margin-bottom: 5px;
}
.nf-holes-section { margin-bottom: 8px; }
.nf-controls {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-top: 12px;
}
.nf-controls button {
  padding: 5px 14px;
  border-radius: 6px;
  border: 0.5px solid #b4b2a9;
  background: transparent;
  color: var(--ink);
  font-size: 13px;
  cursor: pointer;
  font-family: var(--serif);
}
.nf-controls button:disabled { opacity: 0.4; cursor: default; }
.nf-step-lbl {
  font-size: 12px;
  font-family: var(--mono);
  color: var(--ink3);
}

/* step-widget — canvas left, info right; stacks on mobile */
.step-widget {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}
@media (min-width: 600px) {
  .step-widget { flex-direction: row; align-items: flex-start; }
}
.step-widget-info { flex: 1; min-width: 0; }

/* attack widget narr gets a red left border instead of grey */
.at-narr { border-left-color: #f0c0c0; }

/* Q1/Q2 row — hidden by default, single col on narrow, 2-col wider */
.at-qrow { display: none; grid-template-columns: 1fr; gap: 8px; margin-bottom: 10px; }
.at-qrow.at-qrow-visible { display: grid; }
@media (min-width: 420px) {
  .at-qrow.at-qrow-visible { grid-template-columns: 1fr 1fr; }
}
.at-qcard {
  border-radius: 6px;
  padding: 7px 10px;
  border: 1px solid var(--rule);
  background: #f8f6f2;
}
.at-qval {
  font-size: 13px;
  font-weight: 600;
  color: var(--ink);
  margin-top: 3px;
  font-family: var(--mono);
}

.interactive-wrap {
  margin: 2.5rem 0;
  border: 1px solid var(--rule);
  border-radius: 8px;
  overflow: hidden;
  background: white;
}
.interactive-inner { padding: 1rem; }
@media (min-width: 480px) { .interactive-inner { padding: 1.5rem; } }

/* stepper walkthrough */
.stepper-nav {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 0.75rem;
}
.stepper-btn {
  font-family: var(--mono);
  font-size: 16px;
  padding: 0.3rem 0.75rem;
  border: 1px solid var(--rule);
  border-radius: 4px;
  background: var(--page);
  color: var(--ink);
  cursor: pointer;
  user-select: none;
}
.stepper-btn:hover:not(:disabled) { background: var(--rule); }
.stepper-btn:disabled { opacity: 0.35; cursor: default; }
.stepper-step-label {
  font-family: var(--mono);
  font-size: 12px;
  color: var(--ink2);
  flex: 1;
  text-align: center;
}
#stepper-canvas {
  display: block;
  width: 100%;
  max-width: 620px;
  height: auto;
  margin: 0 auto;
}
.stepper-narration {
  margin: 0.75rem 0 0;
  font-size: 15px;
  line-height: 1.6;
  color: var(--ink2);
}

/* collapsible aside */
.aside {
  border: 1px solid var(--rule);
  border-radius: 6px;
  margin: 1.75rem 0;
  background: #fcfaf6;
}
.aside summary {
  padding: 0.7rem 1rem;
  cursor: pointer;
  font-family: var(--mono);
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--ink3);
  user-select: none;
  list-style: none;
}
.aside summary::-webkit-details-marker { display: none; }
.aside summary::before {
  content: '+ ';
  display: inline-block;
  width: 1em;
  color: var(--ink3);
}
.aside[open] summary::before { content: '− '; }
.aside[open] summary { border-bottom: 1px solid var(--rule); }
.aside p {
  padding: 0.9rem 1.1rem;
  margin: 0;
  font-size: 16px;
  color: var(--ink2);
  line-height: 1.65;
}

/* generic article lists — restore indent killed by the universal reset */
article ul, article ol {
  padding-left: 1.75rem;
  margin: 1rem 0 1.5rem;
}
article ul li, article ol li {
  margin-bottom: 0.5rem;
  padding-left: 0.3rem;
  line-height: 1.65;
}
article ul li:last-child, article ol li:last-child { margin-bottom: 0; }

/* the two questions list */
.qq {
  list-style: decimal;
  padding-left: 1.6rem;
  margin: 1.25rem 0;
}
.qq li {
  margin-bottom: 1rem;
  padding-left: 0.4rem;
  line-height: 1.65;
}
.qq li:last-child { margin-bottom: 0; }

.fix-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
  margin: 2rem 0;
}
@media (min-width: 540px) { .fix-grid { grid-template-columns: 1fr 1fr; } }
.fix-card {
  border: 1px solid var(--rule);
  border-radius: 8px;
  padding: 1.25rem;
  background: white;
  min-width: 0;
}
.fix-card h3 {
  font-size: 14px;
  font-family: var(--mono);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--ink3);
  margin-bottom: 0.75rem;
}
.fix-card p { font-size: 15px; line-height: 1.6; margin-bottom: 0.75rem; }
.fix-card pre { margin: 0; font-size: 12px; padding: 0.9rem 1rem; }

.pull-quote {
  font-size: 22px;
  font-style: italic;
  line-height: 1.45;
  color: var(--ink2);
  border-top: 2px solid var(--ink);
  border-bottom: 1px solid var(--rule);
  padding: 1.25rem 0;
  margin: 2.5rem 0;
}

/* Interactive widget (sack-interactive) */
.ic-sub { font-size: 13px; color: #4a4844; margin-bottom: 1rem; line-height: 1.5; font-family: 'Lora', serif; }
.ic-status { display: grid; grid-template-columns: 1fr; gap: 10px; margin-bottom: 1rem; }
@media (min-width: 500px) { .ic-status { grid-template-columns: 1fr 1fr; } }
.ic-card { background: #f8f6f2; border-radius: 6px; padding: 10px 14px; border: 1px solid #e8e4dc; }
.ic-label { font-size: 11px; color: #8a8880; margin-bottom: 4px; font-family: 'JetBrains Mono', monospace; text-transform: uppercase; letter-spacing: 0.06em; }
.ic-val { font-size: 15px; font-weight: 600; font-family: 'JetBrains Mono', monospace; }
.ic-val.t { color: #1a7a5a; }
.ic-val.f { color: #b83232; }
.ic-math { font-size: 11px; color: #8a8880; margin-top: 3px; font-family: 'JetBrains Mono', monospace; }
.ic-boom { margin-top: 1rem; border-radius: 6px; padding: 10px 14px; font-size: 13px; line-height: 1.5; background: #fdeaea; color: #8a1a1a; border: 1px solid #f0c0c0; display: none; font-family: 'Lora', serif; }
.ic-boom.show { display: block; }
.ic-safe { margin-top: 1rem; border-radius: 6px; padding: 10px 14px; font-size: 13px; background: #f8f6f2; color: #8a8880; border: 1px solid #e8e4dc; font-family: 'Lora', serif; }
.ic-hint { font-size: 11px; color: #8a8880; text-align: center; margin-top: 6px; font-family: 'JetBrains Mono', monospace; }
#ic-canvas { display: block; margin: 0 auto; cursor: grab; touch-action: none; max-width: 100%; }

/* Zone-morph diagram (sack-zones) */
.sz-wrap { max-width: 400px; margin-left: auto; margin-right: auto; padding: 1rem; }
.diagram-eyebrow {
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink3);
  text-align: center;
  margin: 0 0 0.5rem;
}
#sz-canvas { display: block; width: 100%; max-width: 360px; height: auto; margin: 0 auto; cursor: pointer; }
.sz-controls { text-align: center; margin-top: 0.75rem; }
.sz-btn {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.05em;
  padding: 6px 18px;
  border: 1px solid var(--rule);
  border-radius: 4px;
  background: white;
  color: var(--ink2);
  cursor: pointer;
}
.sz-btn:hover { background: var(--code-bg); }
#ic-canvas:active { cursor: grabbing; }

/* Bio block */
.bio {
  margin-top: 3rem;
  padding-top: 2rem;
  border-top: 1px solid var(--rule);
}
.bio p {
  font-size: 15px;
  line-height: 1.65;
  color: var(--ink2);
  margin-bottom: 0;
}
.bio-name {
  font-family: var(--mono);
  font-size: 13px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--ink1);
  font-weight: 500;
}