/* Automated Accessibility Enhancer project site.
   Colour pairs meet WCAG 2.2 AA: 4.5:1 or better for text,
   3:1 or better for control borders, in light and dark. */

:root {
  --bg:      #fcfcfa;
  --surface: #ffffff;
  --text:    #16191c;
  --muted:   #4c545b;
  --accent:  #4b2e83;
  --border:  #d7d4cc;
  --control: #8a857b;
  --rule:    #e7e4dc;
  --focus:   #0b57d0;
  --tag-bg:  #eceaf3;
  --tag-fg:  #3b2468;
  --ok-bg:   #e6f2ea;
  --ok-fg:   #1d5a32;
  --bad-bg:  #f8e8e6;
  --bad-fg:  #8a2a1e;

  --measure: 40rem;
  --wrap:    64rem;
  --space:   clamp(1rem, 4vw, 2rem);

  --font: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg:      #111315;
    --surface: #181b1e;
    --text:    #e9ecef;
    --muted:   #a8b1b8;
    --accent:  #c3aef0;
    --border:  #333a3f;
    --control: #6d757a;
    --rule:    #23282b;
    --focus:   #ffd166;
    --tag-bg:  #24202e;
    --tag-fg:  #d3c4f5;
    --ok-bg:   #15271c;
    --ok-fg:   #9fd8b0;
    --bad-bg:  #2e1a17;
    --bad-fg:  #f2b0a5;
  }
}

:root[data-theme="dark"] {
  --bg:      #111315;
  --surface: #181b1e;
  --text:    #e9ecef;
  --muted:   #a8b1b8;
  --accent:  #c3aef0;
  --border:  #333a3f;
  --control: #6d757a;
  --rule:    #23282b;
  --focus:   #ffd166;
  --tag-bg:  #24202e;
  --tag-fg:  #d3c4f5;
  --ok-bg:   #15271c;
  --ok-fg:   #9fd8b0;
  --bad-bg:  #2e1a17;
  --bad-fg:  #f2b0a5;
}

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

[hidden] { display: none !important; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  font-size: 1.0625rem;
  line-height: 1.6;
  overflow-wrap: break-word;
}

/* ---------- Layout ---------- */

.wrap {
  width: 100%;
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: var(--space);
}

main > section {
  padding-block: clamp(2rem, 5vw, 3rem);
}

/* Divider between sections, kept inside the padded column. */
main > section + section {
  background-image: linear-gradient(var(--rule), var(--rule));
  background-size: calc(100% - 2 * var(--space)) 1px;
  background-position: top center;
  background-repeat: no-repeat;
}

/* ---------- Skip link and focus ---------- */

.skip-link {
  position: absolute;
  left: 0.5rem;
  top: -4rem;
  z-index: 10;
  padding: 0.75rem 1rem;
  background: var(--surface);
  color: var(--text);
  border: 2px solid var(--accent);
  border-radius: 6px;
  font-weight: 600;
  text-decoration: none;
}

.skip-link:focus { top: 0.5rem; }

:where(a, button, [tabindex]):focus-visible {
  outline: 3px solid var(--focus);
  outline-offset: 3px;
  border-radius: 4px;
}

/* ---------- Type ---------- */

h1, h2, h3, h4 { line-height: 1.25; margin: 0 0 0.5rem; text-wrap: balance; }

h1 { font-size: clamp(1.9rem, 5vw, 2.75rem); letter-spacing: -0.015em; }
h2 { font-size: clamp(1.4rem, 3.4vw, 1.75rem); margin-bottom: 1.25rem; }
h3 { font-size: 1.125rem; }
h4 { font-size: 1rem; }

p { margin: 0 0 1rem; max-width: var(--measure); }
p:last-child { margin-bottom: 0; }

a { color: var(--accent); text-underline-offset: 0.18em; }
a:hover { text-decoration-thickness: 2px; }

strong { font-weight: 650; }

.code {
  font-family: var(--mono);
  font-size: 0.9em;
  background: var(--tag-bg);
  color: var(--tag-fg);
  padding: 0.1em 0.35em;
  border-radius: 4px;
}

.lede { font-size: 1.1875rem; color: var(--muted); max-width: 44rem; }

.section-intro { color: var(--muted); }

.icon {
  width: 1.5rem;
  height: 1.5rem;
  flex: none;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.75;
  stroke-linecap: round;
  stroke-linejoin: round;
}

/* ---------- Top bar ---------- */

.topbar-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem 1.5rem;
  padding-block: 1rem;
}

.brand {
  font-weight: 650;
  color: var(--text);
  text-decoration: none;
  margin-right: auto;
}

.topbar ul {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem 1.25rem;
  margin: 0;
  padding: 0;
}

.topbar nav a {
  display: inline-block;
  padding-block: 0.35rem;
  color: var(--muted);
  font-size: 0.9375rem;
  text-decoration: none;
}

.topbar nav a:hover { color: var(--text); text-decoration: underline; }

.theme-toggle {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  min-height: 2.25rem;
  padding: 0.3rem 0.75rem;
  font: inherit;
  font-size: 0.9375rem;
  color: var(--text);
  background: transparent;
  border: 1px solid var(--control);
  border-radius: 999px;
  cursor: pointer;
}

.theme-toggle .icon { width: 1.1rem; height: 1.1rem; }

.theme-toggle[aria-pressed="true"] .icon { fill: currentColor; }

/* ---------- Intro ---------- */

.intro { padding-top: clamp(2rem, 6vw, 4rem); }

/* ---------- Buttons ---------- */

.actions { margin-top: 1.5rem; }

.button,
.button-secondary {
  display: inline-flex;
  align-items: center;
  min-height: 2.75rem;
  padding: 0.55rem 1.1rem;
  border-radius: 8px;
  font: inherit;
  font-weight: 650;
  text-decoration: none;
  cursor: pointer;
}

.button { background: var(--accent); color: var(--bg); border: 1px solid var(--accent); }
.button:hover { text-decoration: underline; text-underline-offset: 0.2em; }

.button-secondary { background: transparent; color: var(--text); border: 1px solid var(--control); }
.button-secondary:hover { background: var(--tag-bg); }

/* ---------- Updates ---------- */

.feed {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1rem;
  grid-template-columns: 1fr;
}

@media (min-width: 52rem) {
  .feed { grid-template-columns: repeat(3, minmax(0, 1fr)); }
}

.feed-item {
  display: flex;
  flex-direction: column;
  padding: 1.1rem 1.2rem 1.25rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
}

.feed-item.is-upcoming { border-top: 4px solid var(--accent); }

.feed-item:focus { outline: 3px solid var(--focus); outline-offset: 3px; }

.feed-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.4rem 0.6rem;
  margin: 0 0 0.6rem;
  font-size: 0.875rem;
  color: var(--muted);
}

.tag {
  display: inline-block;
  padding: 0.05rem 0.55rem;
  border-radius: 999px;
  background: var(--tag-bg);
  color: var(--tag-fg);
  font-size: 0.8125rem;
  font-weight: 650;
}

.tag-upcoming { background: var(--accent); color: var(--bg); }

.feed-item h3 { margin-bottom: 0.4rem; }
.feed-item p:last-child { color: var(--muted); font-size: 0.975rem; }

.feed-more { margin-top: 1.25rem; }

/* ---------- Pipeline diagram ---------- */

.pipeline {
  display: grid;
  grid-template-columns: 1fr;
  justify-items: stretch;
  gap: 0.5rem;
  margin-top: 1.75rem;
}

.pipe-col {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1rem 1.1rem 1.1rem;
}

.pipe-main { border: 2px solid var(--accent); }

.pipe-label {
  font-size: 0.8125rem;
  font-weight: 650;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 0.75rem;
}

.nodes,
.steps {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.6rem;
}

.nodes li,
.steps li {
  display: flex;
  align-items: flex-start;
  gap: 0.65rem;
  line-height: 1.35;
}

.nodes .icon,
.steps .icon { color: var(--accent); margin-top: 0.05rem; }

.nodes small,
.steps small {
  display: block;
  color: var(--muted);
  font-size: 0.875rem;
  margin-top: 0.15rem;
}

.steps { counter-reset: step; gap: 0; }

.steps li {
  position: relative;
  padding-bottom: 1rem;
}

.steps li:last-child { padding-bottom: 0; }

/* Connector line between pipeline steps */
.steps li:not(:last-child)::after {
  content: "";
  position: absolute;
  left: calc(0.75rem - 1px);
  top: 1.9rem;
  bottom: 0.2rem;
  width: 2px;
  background: var(--border);
}

.pipe-arrow,
.compare-arrow {
  width: 2rem;
  height: 1.5rem;
  justify-self: center;
  fill: none;
  stroke: var(--muted);
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
  transform: rotate(90deg);
}

@media (min-width: 52rem) {
  .pipeline {
    grid-template-columns: minmax(0, 1fr) auto minmax(0, 1.35fr) auto minmax(0, 1fr);
    align-items: center;
    gap: 0.75rem;
  }

  .pipe-arrow { transform: none; }
}

/* ---------- Before and after example ---------- */

.example {
  margin: 2.5rem 0 0;
  padding: 1.25rem;
  border: 1px solid var(--border);
  border-radius: 12px;
}

.example figcaption p { color: var(--muted); }

.compare {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.75rem;
  margin-top: 1.25rem;
}

@media (min-width: 52rem) {
  .compare {
    grid-template-columns: minmax(0, 1fr) auto minmax(0, 1fr);
    align-items: stretch;
  }

  .compare-arrow { transform: none; align-self: center; }
}

.compare-side { display: flex; flex-direction: column; }
.compare-side .slide { flex: 1; }

.compare-side h4 {
  font-size: 0.8125rem;
  font-weight: 650;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--muted);
}

/* The slide is a list in screen reader order. Grid areas put each shape
   where it sits visually, so the two can differ, which is the point. */
.slide {
  list-style: none;
  counter-reset: order;
  margin: 0;
  padding: 0.9rem;
  display: grid;
  grid-template-columns: 1fr 1fr;
  grid-template-rows: auto 1fr;
  align-content: start;
  grid-template-areas:
    "title title"
    "body  pic";
  gap: 0.6rem;
  background: var(--surface);
  border: 1px solid var(--control);
  border-radius: 6px;
  min-height: 14rem;
}

.shape {
  counter-increment: order;
  position: relative;
  padding: 0.6rem 0.6rem 0.6rem 2.4rem;
  border: 1px dashed var(--control);
  border-radius: 4px;
  font-size: 0.875rem;
  line-height: 1.35;
}

.shape::before {
  content: counter(order);
  position: absolute;
  left: 0.5rem;
  top: 0.5rem;
  width: 1.5rem;
  height: 1.5rem;
  display: grid;
  place-items: center;
  border-radius: 50%;
  background: var(--accent);
  color: var(--bg);
  font-size: 0.8125rem;
  font-weight: 700;
}

.shape-title { grid-area: title; font-weight: 650; font-size: 1rem; }
.shape-body  { grid-area: body; font-family: var(--mono); }
.shape-pic   { grid-area: pic; display: flex; flex-direction: column; gap: 0.4rem; }

.incline {
  width: 100%;
  max-width: 9rem;
  height: auto;
  fill: none;
  stroke: var(--text);
  stroke-width: 2;
  stroke-linejoin: round;
  stroke-linecap: round;
}

.incline .force { stroke: var(--accent); }

.alt {
  display: block;
  margin-top: 0.3rem;
  padding: 0.15rem 0.4rem;
  border-radius: 4px;
  font-size: 0.8125rem;
  font-weight: 600;
}

.alt-missing { background: var(--bad-bg); color: var(--bad-fg); }
.alt-added   { background: var(--ok-bg); color: var(--ok-fg); font-weight: 500; }

@media (max-width: 30rem) {
  .slide {
    grid-template-columns: 1fr;
    grid-template-rows: auto;
    grid-template-areas: "title" "body" "pic";
  }
}

/* ---------- Lists ---------- */

.plain { margin: 0; padding-left: 1.25rem; max-width: var(--measure); }
.plain li { margin-bottom: 0.7rem; color: var(--muted); }
.plain li strong { color: var(--text); }
.plain + p { margin-top: 1.25rem; }

.links { list-style: none; margin: 0; padding: 0; display: grid; gap: 1rem; }
.links .meta { display: block; font-size: 0.9375rem; color: var(--muted); }

.links-inline { display: flex; flex-wrap: wrap; gap: 0.5rem 1.5rem; margin-top: 0.75rem; }

/* ---------- Footer ---------- */

.site-footer { padding-block: 1.5rem 3rem; color: var(--muted); font-size: 0.9375rem; }

.site-footer .wrap { border-top: 1px solid var(--rule); padding-top: 1.5rem; }

/* ---------- Motion, forced colours, print ---------- */

@media (prefers-reduced-motion: no-preference) {
  html { scroll-behavior: smooth; }
}

@media (forced-colors: active) {
  .feed-item, .pipe-col, .slide, .shape, .tag, .alt { border: 1px solid CanvasText; }
  .shape::before { border: 1px solid CanvasText; }
}

@media print {
  body { background: #fff; color: #000; }
  .topbar, .skip-link, .feed-more { display: none; }
  .feed-item[hidden] { display: flex !important; }
  .feed-item, .pipeline, .example { break-inside: avoid; }
}