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

body {
  margin: 0;
  background: var(--color-plane);
  color: var(--color-ink);
  font-family: var(--font-text);
  font-size: var(--text-base);
  line-height: 1.55;
}

a {
  color: inherit;
  text-decoration-color: var(--color-honey);
  text-decoration-thickness: 2px;
  text-underline-offset: 0.2em;
}

a:hover {
  color: var(--color-honey);
}

:focus-visible {
  outline: 2px solid var(--color-honey);
  outline-offset: 3px;
}

.masthead,
main,
.colophon {
  max-width: var(--page-width);
  margin-inline: auto;
  padding-inline: var(--space-gutter);
}

/* Masthead: a wide headline over a honeycomb wash */
.masthead {
  position: relative;
  padding-block: var(--space-section) calc(var(--space-section) / 2);
}

.masthead::before {
  content: "";
  position: absolute;
  inset: 0 0 auto auto;
  width: min(46vw, 34rem);
  height: 100%;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='56' height='97' viewBox='0 0 56 97'%3E%3Cpath d='M28 0l28 16v33L28 65 0 49V16zM28 65l28 16v16H0V81z' fill='none' stroke='%23b8740a' stroke-opacity='.28'/%3E%3C/svg%3E");
  mask-image: linear-gradient(to left, #000, transparent);
  pointer-events: none;
}

.masthead-kicker {
  margin: 0 0 1rem;
  color: var(--color-honey);
  font-size: var(--text-small);
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

h1 {
  position: relative;
  max-width: 14ch;
  margin: 0;
  font-family: var(--font-display);
  font-size: var(--text-hero);
  font-weight: 500;
  letter-spacing: -0.02em;
  line-height: 0.98;
}

.masthead-lede {
  position: relative;
  max-width: var(--measure);
  margin: 1.75rem 0 0;
  color: var(--color-ink-soft);
  font-size: var(--text-lede);
}

.notice {
  position: relative;
  max-width: var(--measure);
  margin: 1.5rem 0 0;
  padding: 0.75rem 1rem;
  border-left: 4px solid var(--color-notice-rule);
  background: var(--color-notice);
  font-size: var(--text-small);
}

/* Controls: one row above everything it scopes */
.controls {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem 2rem;
  margin-inline: calc(var(--space-gutter) * -0.5);
  padding: 0.85rem calc(var(--space-gutter) * 0.5);
  border-block: 1px solid var(--color-rule);
  background: color-mix(in srgb, var(--color-plane) 92%, transparent);
  backdrop-filter: blur(10px);
}

.controls-group {
  display: flex;
  flex-wrap: wrap;
  align-items: end;
  gap: 0.75rem 1.25rem;
  min-width: 0;
  margin: 0;
  padding: 0;
  border: 0;
}

.controls-group legend {
  padding: 0;
  color: var(--color-ink-muted);
  font-size: 0.6875rem;
  font-weight: 700;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

.field {
  display: grid;
  gap: 0.25rem;
  font-size: var(--text-small);
  color: var(--color-ink-soft);
}

.field-check {
  grid-auto-flow: column;
  align-items: center;
  gap: 0.5rem;
  padding-bottom: 0.45rem;
}

.field input[type="number"],
.field select {
  min-height: 2.25rem;
  padding: 0.3rem 0.6rem;
  border: 1px solid var(--color-rule);
  border-radius: var(--radius-control);
  background: var(--color-surface);
  color: var(--color-ink);
  font: inherit;
}

.field input[type="number"] {
  width: 6.5rem;
}

.field input[type="range"] {
  width: 9rem;
  accent-color: var(--color-honey);
}

.field output {
  color: var(--color-ink);
  font-weight: 700;
  font-variant-numeric: tabular-nums;
}

.run-button {
  min-height: 2.25rem;
  padding: 0.35rem 1.15rem;
  border: 1px solid var(--color-ink);
  border-radius: var(--radius-control);
  background: var(--color-ink);
  color: var(--color-plane);
  font: inherit;
  font-size: var(--text-small);
  font-weight: 700;
  letter-spacing: 0.04em;
  cursor: pointer;
  transition:
    transform var(--duration-fast) var(--ease-out),
    background-color var(--duration-fast) var(--ease-out);
}

.run-button:hover {
  background: var(--color-honey);
  border-color: var(--color-honey);
}

.run-button:active {
  transform: translateY(1px);
}

.run-button:disabled {
  opacity: 0.55;
  cursor: progress;
}

.status {
  min-height: 1.5rem;
  margin: 1rem 0 0;
  color: var(--color-ink-muted);
  font-size: var(--text-small);
}

.status[data-state="failed"] {
  color: var(--diverging-negative);
  font-weight: 600;
}

/* Report */
.report {
  min-height: 60vh;
  transition: opacity var(--duration-normal) var(--ease-out);
}

.report[aria-busy="true"] {
  opacity: 0.45;
}

.chapter {
  display: grid;
  gap: 1.5rem var(--space-gutter);
  padding-block: calc(var(--space-section) / 2);
  border-top: 1px solid var(--color-rule);
  animation: rise var(--duration-normal) var(--ease-out) both;
}

.chapter:first-child {
  border-top: 0;
}

.chapter-heading {
  display: grid;
  gap: 0.5rem;
  align-content: start;
}

.chapter-number {
  color: var(--color-honey);
  font-family: var(--font-display);
  font-size: var(--text-section);
  font-style: italic;
  line-height: 1;
}

.chapter h2 {
  margin: 0;
  font-family: var(--font-display);
  font-size: var(--text-section);
  font-weight: 500;
  letter-spacing: -0.01em;
  line-height: 1.05;
}

.chapter-heading p {
  max-width: 38ch;
  margin: 0;
  color: var(--color-ink-soft);
}

.chapter-body {
  display: grid;
  gap: var(--space-card);
  min-width: 0;
}

.field-invite {
  display: grid;
  gap: 1rem;
  justify-items: start;
}

.field-invite p {
  max-width: var(--measure);
  margin: 0;
  color: var(--color-ink-soft);
}

.pair-list {
  margin: 0;
  padding: 0;
  list-style: none;
  font-size: var(--text-small);
}

.pair-list li {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  padding-block: 0.4rem;
  border-bottom: 1px solid var(--color-rule);
}

.pair-list strong {
  font-variant-numeric: tabular-nums;
}

.colophon {
  padding-block: 2rem var(--space-section);
  border-top: 1px solid var(--color-rule);
  color: var(--color-ink-muted);
  font-size: var(--text-small);
}

@media (min-width: 64rem) {
  .chapter {
    grid-template-columns: minmax(0, 5fr) minmax(0, 11fr);
  }

  .controls {
    position: sticky;
    top: 0;
    z-index: 2;
  }

  .chapter-heading {
    position: sticky;
    top: 6.5rem;
  }

  .chapter-body.is-split {
    grid-template-columns: minmax(0, 3fr) minmax(0, 2fr);
    align-items: start;
  }
}

@keyframes rise {
  from {
    opacity: 0;
    transform: translateY(12px);
  }
}

@media (prefers-reduced-motion: reduce) {
  .chapter {
    animation: none;
  }

  .report,
  .run-button {
    transition: none;
  }
}