/* ── Design tokens ── */
:root {
  color-scheme: light;
  --bg: #f3f3f0;
  --paper: #fcfcfa;
  --ink: #1f1f1b;
  --muted: #66665f;
  --rule: #d6d6cf;
  --pass-ink: #0a8f3b;
  --pass-mark: #10b34a;
  --fail-ink: #a1261a;
  --fail-mark: #d63b2d;
  --xfail-ink: #c4776e;
  --xfail-mark: #e0978f;
  --accent: #2f64b3;
  --code-bg: #efefea;
  --note-bg: #f5f5f1;
  --pass-bg: #e8f0e6;
  --fail-bg: #f0e4e2;
  --xfail-bg: #f5eeec;
  --font-mono: "SFMono-Regular", Menlo, Consolas, monospace;

  --safe-top: env(safe-area-inset-top, 0px);
  --safe-right: env(safe-area-inset-right, 0px);
  --safe-bottom: env(safe-area-inset-bottom, 0px);
  --safe-left: env(safe-area-inset-left, 0px);
}

/* ── Reset ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; }

/* ── Body ── */
html { background: var(--bg); }
body {
  font-family: "Avenir Next", "Helvetica Neue", "Segoe UI", sans-serif;
  color: var(--ink);
  background: var(--bg);
}

/* ── Page layout ── */
main {
  max-width: 99rem;
  margin-inline: auto;
  padding:
    calc(2.75rem + var(--safe-top))
    calc(1.5rem + var(--safe-right))
    calc(4rem + var(--safe-bottom))
    calc(1.5rem + var(--safe-left));
}

.layout {
  display: grid;
  grid-template-columns: 20rem minmax(0, 54rem) 20rem;
  column-gap: 2.5rem;
  align-items: start;
}

/* ── Table of contents ── */
.toc {
  position: sticky;
  top: calc(2.75rem + var(--safe-top));
  max-height: calc(100dvh - 2.75rem - var(--safe-top) - var(--safe-bottom));
  overflow-y: auto;
  font-size: 0.82rem;
  line-height: 1.45;
}

.toc-inner { padding: 0 0 0 0.85rem; }

.toc-title {
  margin-bottom: 0.75rem;
  padding-bottom: 1.125rem;
  color: var(--muted);
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

/* -- TOC groups -- */
.toc-group { margin-bottom: 0.6rem; }

.toc-group-title {
  display: flex;
  align-items: center;
  gap: 0.35rem;
  width: 100%;
  background: none;
  border: none;
  padding: 0.25rem 0;
  font: inherit;
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--muted);
  cursor: pointer;
  position: relative;
}

.toc-group-title::before {
  content: ">";
  font-size: 0.65rem;
  display: inline-block;
  transition: transform 0.15s ease;
}

.toc-group.expanded > .toc-group-title::before {
  transform: rotate(90deg);
}

.toc-group-body {
  display: none;
  padding-left: 0.5rem;
}

.toc-group.expanded > .toc-group-body {
  display: block;
}

.toc-group-title.failed::after,
.toc-group-title.expected-fail::after {
  content: "";
  width: 0.38rem;
  height: 0.38rem;
  border-radius: 50%;
  background: var(--fail-mark);
  margin-left: auto;
}
.toc-group-title.expected-fail::after {
  background: var(--xfail-mark);
}

/* -- TOC type badge -- */
.toc-type-badge {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.55rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  padding: 0.05em 0.3em;
  border-radius: 0.12rem;
  vertical-align: baseline;
  background: hsl(var(--type-hue) 55% 92%);
  color: hsl(var(--type-hue) 50% 35%);
  border: 1px solid hsl(var(--type-hue) 40% 82%);
}

.toc-spec {
  margin-bottom: 0.5rem;
}
.toc-spec:last-child { margin-bottom: 0; }

.toc-spec-header {
  display: flex;
  align-items: baseline;
  gap: 0.35rem;
  margin-bottom: 0.35rem;
  position: relative;
}

.toc-spec-title {
  font-weight: 600;
  color: var(--ink);
  text-decoration: none;
}

.toc-list {
  list-style: none;
  padding-left: 0.85rem;
}

.toc-item {
  margin: 0.1rem 0;
}
.toc-item:first-child { margin-top: 0; }

.toc-link {
  display: block;
  text-decoration: none;
  color: var(--muted);
  position: relative;
  transition: color 120ms ease;
}
.toc-link:hover { color: var(--ink); }
.toc-link.active { color: var(--ink); font-weight: 600; }

.toc-spec.current > .toc-spec-title {
  color: var(--ink);
  font-weight: 600;
}

.toc-snippet {
  color: var(--muted);
  font-size: 0.76rem;
  font-style: italic;
  margin: 0.1rem 0 0;
  line-height: 1.35;
}

.toc-spec-header:has(.toc-spec-title.failed)::before,
.toc-spec-header:has(.toc-spec-title.expected-fail)::before,
.toc-link.failed::before,
.toc-link.expected-fail::before {
  content: "";
  position: absolute;
  left: -0.85rem;
  top: 50%;
  translate: 0 -50%;
  width: 0.38rem;
  height: 0.38rem;
  border-radius: 50%;
  background: var(--fail-mark);
}
.toc-spec-header:has(.toc-spec-title.expected-fail)::before,
.toc-link.expected-fail::before {
  background: var(--xfail-mark);
}

.toc-level-4 { padding-left: 0.7rem; }
.toc-level-5,
.toc-level-6 { padding-left: 1.4rem; }

.toc-children {
  list-style: none;
  padding-left: 0.85rem;
  display: none;
}

.toc-item.expanded > .toc-children { display: block; }

/* ── Content area ── */
.content { min-width: 0; }

.content-meta {
  display: flex;
  align-items: baseline;
  gap: 0.5rem;
  margin-bottom: 0.4rem;
  font-size: 0.82rem;
  line-height: 1;
}

.pill {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 600;
}
.pill.pass { color: var(--pass-ink); }
.pill.fail { color: var(--fail-ink); }
.pill.xfail { color: var(--xfail-ink); }

.meta-date { color: var(--muted); margin-left: auto; }

/* ── Spec articles ── */
.spec + .spec { padding-top: 2rem; }

.spec-body {
  line-height: 1.9;
}
.spec-body > :first-child { margin-top: 0; }

.spec-body h1 {
  font-family: serif;
  font-size: 2.8rem;
  line-height: 1.15;
  letter-spacing: -0.01em;
  margin-bottom: 0.4rem;
  text-wrap: balance;
}

.doc-type {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.65rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  padding: 0.15em 0.5em;
  border-radius: 0.2rem;
  background: hsl(var(--type-hue) 55% 92%);
  color: hsl(var(--type-hue) 50% 35%);
  border: 1px solid hsl(var(--type-hue) 40% 82%);
}

.spec-body :is(h2, h3, h4, h5, h6) {
  font-family: serif;
  line-height: 1.15;
  padding: 0.5em 0 0.35em;
  margin-top: 0.75em;
  text-wrap: balance;
  letter-spacing: -0.01em;
  position: sticky;
  background: var(--bg);
  border-bottom: 1px solid color-mix(in srgb, var(--rule) 60%, transparent);
}

.spec-body :is(h2, h3, h4, h5, h6).stuck-last::after {
  content: "";
  position: absolute;
  inset: 100% 0 auto 0;
  height: 4px;
  background: linear-gradient(rgba(0, 0, 0, 0.06), transparent);
  pointer-events: none;
}

.spec-body > :first-child > :first-child { margin-top: 0; }

.spec-body :is(p, ul, ol, dl, blockquote):not(.exec-block-footer):not(.exec-table-footer) { margin: 1.25rem 0 0; }
.spec-body :is(p, ul, ol, dl, blockquote):not(.exec-block-footer):not(.exec-table-footer):first-child { margin-top: 0; }
.spec-body pre { margin: 1rem 0; }
.spec-body li { margin: 0.25rem 0; }
.spec-body ul, .spec-body ol { padding-left: 1.5rem; }

.spec-body h2 { font-size: 2.5rem; top: 0; padding-top: calc(0.5em + var(--safe-top)); z-index: 4; }
.spec-body h3 { font-size: 1.85rem; top: calc(5rem + 1px + var(--safe-top)); z-index: 3; }
.spec-body h4 { font-size: 1.4rem;  top: calc(8.7rem + 2px + var(--safe-top)); z-index: 2; }
.spec-body :is(h5, h6) { font-size: 1.08rem; top: calc(11.5rem + 3px + var(--safe-top)); z-index: 1; }

.spec-body .s2 { scroll-margin-top: 0; }
.spec-body .s3 { scroll-margin-top: calc(5rem + 1px + var(--safe-top)); }
.spec-body .s4, .spec-body .s5, .spec-body .s6 { scroll-margin-top: calc(8.7rem + 2px + var(--safe-top)); }

.status {
  font-weight: 600;
  font-size: 0.95rem;
}
.status.passed { color: var(--pass-ink); }
.status.failed { color: var(--fail-ink); }
.status.expected-fail { color: var(--xfail-ink); }

/* ── Executable blocks ── */
.exec-block,
.exec-table-block {
  margin: 0.75rem 0;
}

.exec-block { scroll-margin-top: 1.5rem; }

.exec-source {
  padding: 0.8rem 0.9rem;
  border: 1px solid var(--rule);
  border-radius: 0.2rem;
  border-left: 3px solid transparent;
  font-family: var(--font-mono);
  font-size: 0.92rem;
  line-height: 1.45;
  white-space: pre-wrap;
  overflow-x: auto;
  background: var(--code-bg);
}
.exec-source.resolved {
  margin-top: 0.4rem;
  border: 1px solid var(--rule);
}

.exec-block.passed > .exec-source:not(.resolved) {
  border-left-color: var(--pass-mark);
  background: var(--pass-bg);
}

.exec-block.failed > .exec-source:not(.resolved) {
  border-left-color: var(--fail-mark);
  background: var(--fail-bg);
}

.exec-block.expected-fail > .exec-source:not(.resolved) {
  border-left-color: var(--xfail-mark);
  background: var(--xfail-bg);
}

/* ── Collapsible blocks with summary lines ── */
.exec-detail {
  border-radius: 0.2rem;
}

.exec-detail > summary.exec-source {
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
  list-style: none;
  font-family: var(--font-body);
  font-size: 0.95rem;
  white-space: normal;
  border-bottom-left-radius: 0;
  border-bottom-right-radius: 0;
}

.exec-detail > summary.exec-source::-webkit-details-marker { display: none; }
.exec-detail > summary.exec-source::marker { display: none; content: ""; }

.exec-detail:not([open]) > summary.exec-source {
  border-radius: 0.2rem;
}

.exec-expand-marker::after {
  content: ">";
  font-size: 0.7rem;
  color: var(--muted);
  transition: transform 0.15s ease;
  display: inline-block;
}

.exec-detail[open] > summary .exec-expand-marker::after {
  transform: rotate(90deg);
}

.exec-source-body {
  border-top: 1px solid var(--rule);
  border-top-left-radius: 0;
  border-top-right-radius: 0;
}

.exec-block.passed > .exec-detail > summary.exec-source,
.exec-block.passed > .exec-detail > .exec-source-body {
  border-left-color: var(--pass-mark);
  background: var(--pass-bg);
}

.exec-block.failed > .exec-detail > summary.exec-source,
.exec-block.failed > .exec-detail > .exec-source-body {
  border-left-color: var(--fail-mark);
  background: var(--fail-bg);
}

.doctest-steps {
  font-family: var(--font-mono);
  font-size: 0.92rem;
  line-height: 1.45;
  white-space: pre-wrap;
}

.doctest-prompt { color: var(--muted); user-select: none; }

.doctest-output.passed { color: var(--pass-ink); }
.doctest-output.failed { color: var(--fail-ink); }

.doctest-expected {
  color: var(--muted);
  font-style: italic;
}

.doctest-expected-label {
  font-size: 0.82rem;
}

.wildcard-fold {
  display: inline;
}
.wildcard-fold > summary {
  display: inline;
  cursor: pointer;
  color: var(--muted);
  font-style: italic;
  list-style: none;
}
.wildcard-fold > summary::-webkit-details-marker { display: none; }
.wildcard-fold[open] > summary {
  display: block;
  color: var(--muted);
  opacity: 0.6;
}
.wildcard-expanded {
  border-left: 2px solid var(--pass-mark);
  padding-left: 0.6em;
  display: inline-block;
}

.exec-bindings {
  margin-top: 0.35rem;
  font-size: 0.85rem;
  font-style: italic;
  color: var(--muted);
  font-family: var(--font-mono);
}

.exec-block-footer, .exec-table-footer {
  text-align: right;
  font-size: 0.8rem;
  color: var(--muted);
  font-family: var(--font-mono);
}

.exec-note {
  margin: 0.75rem 0 0.35rem;
  color: var(--muted);
  font-size: 0.92rem;
}

.exec-message {
  margin-top: 0.75rem;
  color: var(--fail-ink);
  font-weight: 600;
}

/* ── Executable tables ── */
.exec-table-block { overflow-x: auto; }

.exec-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.95rem;
}
.exec-table :is(th, td) {
  padding: 0.7rem 0.75rem;
  border: 1px solid var(--rule);
  vertical-align: top;
  text-align: left;
}
.exec-table thead th {
  border: 0;
  padding-bottom: 0;
  font-weight: normal;
  font-size: 0.8rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--muted);
  background: var(--bg);
}
.exec-table thead th:first-child { border-left: 3px solid transparent; }
.exec-table tbody td:first-child { border-left: 3px solid transparent; }

.exec-table tbody tr.passed td { background: var(--pass-bg); }
.exec-table tbody tr.passed td:first-child { border-left-color: var(--pass-mark); }
.exec-table tbody tr.failed td { background: var(--fail-bg); }
.exec-table tbody tr.failed td:first-child { border-left-color: var(--fail-mark); }
.exec-table tbody tr.expected-fail td { background: var(--xfail-bg); }
.exec-table tbody tr.expected-fail td:first-child { border-left-color: var(--xfail-mark); }

/* ── Prose code blocks & tables ── */
.spec-body :not(.exec-source) > pre {
  padding: 0.8rem 0.9rem;
  background: var(--code-bg);
  border: 1px solid var(--rule);
  border-radius: 0.2rem;
  overflow-x: auto;
}

.spec-body table:not(.exec-table) {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.95rem;
  margin: 1rem 0;
  overflow-x: auto;
  display: block;
}
.spec-body table:not(.exec-table) :is(th, td) {
  padding: 0.5rem 0.75rem;
  border: 1px solid var(--rule);
  text-align: left;
}
.spec-body table:not(.exec-table) th {
  background: var(--code-bg);
  font-size: 0.85rem;
}

/* ── Inline assertions ── */
.inline-var {
  font-family: var(--font-mono);
  font-size: 0.94em;
  padding: 0.1em 0.35em;
  border-radius: 0.2rem;
  background: var(--pass-bg);
  color: var(--pass-ink);
}

.inline-expect {
  font-family: var(--font-mono);
  font-size: 0.94em;
  padding: 0.1em 0.35em;
  border-radius: 0.2rem;
}

.inline-expect.passed {
  background: var(--pass-bg);
  color: var(--pass-ink);
}

.inline-expect.failed {
  background: var(--fail-bg);
  color: var(--fail-ink);
  position: relative;
  padding-top: 0.02em;
  padding-bottom: 0.02em;
}

.inline-expect.expected-fail {
  background: var(--xfail-bg);
  color: var(--xfail-ink);
  position: relative;
  padding-top: 0.02em;
  padding-bottom: 0.02em;
}

.inline-expect.expected-fail > .annotation,
.inline-expect.failed > .annotation,
.inline-check > .annotation {
  position: absolute;
  left: 0;
  bottom: 100%;
  font-size: 0.8em;
  line-height: 1;
  color: var(--muted);
  font-style: italic;
  white-space: nowrap;
  pointer-events: none;
}

.spec-body :is(p, li):has(.inline-expect.failed, .inline-check.failed) {
  position: relative;
}
.spec-body :is(p, li):has(.inline-expect.failed, .inline-check.failed)::before {
  content: "";
  position: absolute;
  left: -0.85rem;
  top: 0.55em;
  width: 0.38rem;
  height: 0.38rem;
  border-radius: 50%;
  background: var(--fail-mark);
}

.inline-check {
  font-family: var(--font-mono);
  font-size: 0.94em;
  padding: 0.1em 0.35em;
  border-radius: 0.2rem;
}

.inline-check.passed {
  background: var(--pass-bg);
  color: var(--pass-ink);
}

.inline-check.failed {
  background: var(--fail-bg);
  color: var(--fail-ink);
}

.inline-check:has(.annotation) {
  position: relative;
  padding-top: 0.02em;
  padding-bottom: 0.02em;
}

/* ── Trace links ── */

.trace-link {
  position: relative;
  padding-top: 0.02em;
}

.trace-link > .annotation {
  position: absolute;
  left: 0;
  bottom: calc(100% - 0.35em);
  font-size: 0.8em;
  line-height: 1;
  color: var(--muted);
  font-style: italic;
  white-space: nowrap;
  pointer-events: none;
}

/* ── Cell styles ── */
.cell-template { font-family: var(--font-mono); white-space: pre-wrap; }

.cell-resolved {
  margin-top: 0.35rem;
  color: var(--muted);
  font-family: var(--font-mono);
  font-size: 0.92rem;
}

.cell-actual {
  margin-top: 0.35rem;
  color: var(--fail-ink);
  font-size: 0.85rem;
  font-style: italic;
  white-space: pre-wrap;
}

.failure-diff {
  margin: 0.75rem 0 0;
  padding: 0.65rem 0.8rem;
  background: var(--fail-bg);
  border-left: 3px solid var(--fail-mark);
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 0.35rem 0.75rem;
  align-items: baseline;
}
.failure-diff.compact { padding: 0.65rem 0.75rem; border-left: 0; }
.failure-diff dt {
  color: var(--muted);
  font-size: 0.82rem;
  line-height: 1.45;
  text-transform: uppercase;
  letter-spacing: 0.03em;
}
.failure-diff dd {
  font-family: var(--font-mono);
  line-height: 1.45;
  word-break: break-word;
}

/* ── Links & code ── */
a { color: var(--accent); }

code, pre, kbd, samp {
  font-family: var(--font-mono);
  font-size: 0.94em;
  line-height: 1.45;
}

:not(pre) > code {
  padding: 0.15em 0.35em;
  background: #e6e6df;
  border-radius: 0.2rem;
}

.exec-source :not(pre) > code,
.exec-source > code {
  padding: 0;
  background: transparent;
}

/* ── Per-page trace context (right panel) ── */
.trace-context {
  position: sticky;
  top: calc(2.75rem + var(--safe-top));
  max-height: calc(100dvh - 2.75rem - var(--safe-top) - var(--safe-bottom));
  overflow-y: auto;
  min-width: 0;
  font-size: 0.82rem;
  line-height: 1.45;
}

.trace-ctx-inner { padding: 0 0.85rem 0 0; }

.trace-ctx-title {
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 0.75rem;
  padding-bottom: 1.125rem;
}

.trace-ctx-parent,
.trace-ctx-child {
  padding: 0.15rem 0;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.trace-ctx-parent a,
.trace-ctx-child a {
  color: var(--ink);
  text-decoration: none;
}
.trace-ctx-parent a:hover,
.trace-ctx-child a:hover { color: var(--accent); }

.trace-ctx-edge {
  font-style: italic;
  color: var(--muted);
  font-size: 0.75rem;
}

.trace-ctx-current {
  padding: 0.3rem 0.5rem;
  margin: 0.25rem 0;
  background: var(--bg);
  border-radius: 4px;
  font-weight: 600;
}

.trace-ctx-child {
  padding-left: 1.5rem;
}

/* ── Mobile layout ── */
.mobile-title { display: none; }

@media (max-width: 960px) {
  .layout {
    grid-template-columns: minmax(0, 1fr);
    gap: 0;
  }

  .content { display: contents; }

  .mobile-title {
    display: block;
    order: 1;
  }
  .mobile-title h1 { margin: 0; }

  .toc {
    position: static;
    order: 2;
    margin-top: 1.5rem;
    margin-bottom: 1rem;
  }

  .toc-inner { padding-left: 0; padding-bottom: 1rem; }

  .toc-title,
  .trace-ctx-title {
    font-size: 1.15rem;
    letter-spacing: 0.04em;
  }

  .trace-context {
    position: static;
    order: 3;
    max-width: none;
    min-width: 0;
    margin-bottom: 3rem;
  }

  .content-header { order: 4; }
  .content-body { order: 5; }
}

@media (min-width: 961px) {
  .toc-title,
  .trace-ctx-title {
    border-bottom: 1px solid var(--rule);
  }
}

.site-footer {
  max-width: 52rem;
  margin: 3rem auto 0;
  padding: 0 1rem 4rem;
  text-align: center;
  font-size: 0.84rem;
  color: var(--muted);
}
.site-footer hr {
  border: none;
  border-top: 1px solid var(--muted);
  opacity: 0.4;
  margin-bottom: 0.75rem;
}
.site-footer a {
  color: var(--muted);
  text-decoration: underline;
}

/* ── Trace page ── */
.trace-meta {
  color: var(--muted);
  font-size: 0.88rem;
  margin: 0.5rem 0 1.5rem;
}

/* ── Trace tag (type badge) ── */
.trace-tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.6rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  padding: 0.1em 0.4em;
  border-radius: 0.15rem;
  min-width: 2.5em;
  text-align: center;
  vertical-align: baseline;
  background: hsl(var(--type-hue) 55% 92%);
  color: hsl(var(--type-hue) 50% 35%);
  border: 1px solid hsl(var(--type-hue) 40% 82%);
}