:root {
  --bg: #ffffff;
  --fg: #111111;
  --muted: #6b6b6b;
  --border: #dddddd;
  --code-bg: #f7f7f7;
}

* {
  box-sizing: border-box;
}

html, body {
  margin: 0;
  padding: 0;
}

body {
  background: var(--bg);
  color: var(--fg);
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace;
  font-size: 14px;
  line-height: 1.65;
}

a {
  color: var(--fg);
}

a:not(.no-underline) {
  text-decoration-color: var(--border);
  text-underline-offset: 3px;
}

a {
  transition: text-decoration-color 150ms ease;
}

a:hover {
  text-decoration-color: var(--fg);
}

.topbar {
  border-bottom: 1px solid var(--border);
}

.topbar-inner {
  max-width: 760px;
  margin: 0 auto;
  padding: 20px 24px;
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
}

.topbar .brand {
  font-weight: 600;
  font-size: 15px;
  text-decoration: none;
  letter-spacing: -0.01em;
}

.topbar nav {
  display: flex;
  flex-wrap: wrap;
  gap: 4px 18px;
}

.topbar nav a {
  color: var(--muted);
  text-decoration: none;
  font-size: 13px;
}

.topbar nav a:hover,
.topbar nav a[aria-current="page"] {
  color: var(--fg);
}

.topbar nav a[aria-current="page"] {
  border-bottom: 1px solid var(--fg);
}

.nav-group {
  position: relative;
}

.nav-group summary {
  color: var(--muted);
  font-size: 13px;
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: center;
  gap: 4px;
  user-select: none;
}

.nav-group summary::-webkit-details-marker,
.nav-group summary::marker {
  display: none;
  content: '';
}

.nav-group summary:hover,
.nav-group.has-current summary {
  color: var(--fg);
}

.nav-group.has-current summary {
  border-bottom: 1px solid var(--fg);
}

.nav-group summary .caret {
  font-size: 9px;
  opacity: 0.6;
}

.nav-group .dropdown {
  position: absolute;
  top: calc(100% + 10px);
  left: 0;
  background: var(--bg);
  border: 1px solid var(--border);
  padding: 6px 0;
  min-width: 130px;
  max-width: calc(100vw - 32px);
  z-index: 20;
  display: flex;
  flex-direction: column;
}

.nav-group .dropdown a {
  padding: 6px 14px;
  white-space: nowrap;
  font-size: 13px;
}

.nav-group .dropdown a:hover {
  background: var(--code-bg);
}

.nav-group .dropdown a {
  transition: background 150ms ease;
}

.icon-link {
  display: inline-flex;
  align-items: center;
  color: var(--muted);
  transition: color 150ms ease;
}

.icon-link:hover {
  color: var(--fg);
}

.icon-link svg {
  width: 16px;
  height: 16px;
}

main {
  max-width: 760px;
  margin: 0 auto;
  padding: 48px 24px 96px;
}

main > .lede {
  color: var(--muted);
  margin: -8px 0 40px;
  max-width: 56ch;
}

h1 {
  font-size: 22px;
  font-weight: 600;
  letter-spacing: -0.01em;
  margin: 0 0 8px;
}

h2 {
  font-size: 16px;
  font-weight: 600;
  margin: 48px 0 16px;
  padding-top: 24px;
  border-top: 1px solid var(--border);
}

main > h2:first-of-type {
  border-top: none;
  padding-top: 0;
  margin-top: 0;
}

h3 {
  font-size: 14px;
  font-weight: 600;
  margin: 28px 0 10px;
}

p {
  margin: 0 0 16px;
}

ul, ol {
  margin: 0 0 16px;
  padding-left: 22px;
}

li {
  margin-bottom: 6px;
}

code {
  background: var(--code-bg);
  border: 1px solid var(--border);
  border-radius: 2px;
  padding: 1px 5px;
  font-size: 0.95em;
}

pre {
  position: relative;
  background: var(--code-bg);
  border: 1px solid var(--border);
  padding: 34px 16px 14px;
  overflow-x: auto;
  margin: 0 0 20px;
  line-height: 1.55;
}

pre::before {
  content: '';
  position: absolute;
  top: 14px;
  left: 16px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: #ff5f57;
  box-shadow: 16px 0 0 #febc2e, 32px 0 0 #28c840;
}

pre code {
  background: none;
  border: none;
  padding: 0;
}

table {
  width: 100%;
  border-collapse: collapse;
  margin: 0 0 24px;
  font-size: 13px;
}

th, td {
  text-align: left;
  padding: 8px 12px 8px 0;
  border-bottom: 1px solid var(--border);
  vertical-align: top;
}

th {
  color: var(--muted);
  font-weight: 600;
  white-space: nowrap;
}

.callout {
  border: 1px solid var(--border);
  border-left: 3px solid var(--fg);
  padding: 12px 16px;
  margin: 0 0 20px;
}

.callout p:last-child {
  margin-bottom: 0;
}

.callout-label {
  display: block;
  font-weight: 600;
  margin-bottom: 4px;
}

.grid-cols-2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}

.card {
  border: 1px solid var(--border);
  padding: 16px;
  transition: transform 150ms ease, border-color 150ms ease;
}

.card:hover {
  transform: translateY(-2px);
  border-color: var(--fg);
}

.card h3 {
  margin-top: 0;
}

.kv {
  display: grid;
  grid-template-columns: max-content 1fr;
  gap: 6px 20px;
  margin: 0 0 20px;
}

.kv dt {
  color: var(--muted);
}

.kv dd {
  margin: 0;
}

.result-block {
  border: 1px solid var(--border);
  padding: 12px 16px;
  font-size: 13px;
  line-height: 1.6;
  margin: 0 0 20px;
  white-space: pre-wrap;
}

.controls {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 12px;
}

button {
  font: inherit;
  background: var(--fg);
  color: var(--bg);
  border: 1px solid var(--fg);
  padding: 8px 16px;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  transition: opacity 150ms ease;
}

button:disabled {
  background: var(--bg);
  color: var(--muted);
  border-color: var(--border);
  cursor: default;
}

button:not(:disabled):hover {
  opacity: 0.75;
}

button .hint {
  color: inherit;
  opacity: 0.5;
  font-size: 12px;
}

.output {
  min-height: 160px;
  max-height: 380px;
  overflow-y: auto;
  border: 1px solid var(--border);
  padding: 12px;
  white-space: pre-wrap;
  word-break: break-word;
  margin-bottom: 12px;
  font-size: 13px;
}

.output .stderr {
  color: var(--muted);
  font-style: italic;
}

.output .status {
  color: var(--muted);
}

.stats:empty {
  display: none;
}

.stats {
  border-top: 1px solid var(--border);
  padding-top: 16px;
  margin-bottom: 20px;
}

.stats dl {
  display: grid;
  grid-template-columns: max-content 1fr;
  gap: 6px 20px;
  margin: 0;
}

.stats dt {
  color: var(--muted);
}

.stats dd {
  margin: 0;
}

.stats .verdict {
  font-weight: 600;
}

.stats.verdict-bad .verdict {
  text-decoration: underline;
  text-underline-offset: 3px;
}

.hero {
  padding: 12px 0 8px;
}

.hero h1 {
  font-size: 30px;
  margin-bottom: 12px;
}

.hero .lede {
  font-size: 16px;
  margin-bottom: 28px;
  max-width: 46ch;
}

.btn-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 8px;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font: inherit;
  text-decoration: none;
  padding: 9px 16px;
  border: 1px solid var(--fg);
  transition: opacity 150ms ease, background 150ms ease, transform 150ms ease;
}

.btn:active {
  transform: translateY(1px);
}

.btn svg {
  width: 15px;
  height: 15px;
}

.btn-primary {
  background: var(--fg);
  color: var(--bg);
}

.btn-primary:hover {
  opacity: 0.75;
}

.btn-secondary {
  background: var(--bg);
  color: var(--fg);
}

.btn-secondary:hover {
  background: var(--code-bg);
}

.stat-row {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  padding: 24px 0;
  margin: 40px 0;
}

.stat-row .num {
  font-size: 22px;
  font-weight: 600;
  letter-spacing: -0.01em;
}

.stat-row .label {
  color: var(--muted);
  font-size: 12px;
  margin-top: 2px;
}

.bench-row {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 12px;
}

.bench-label {
  width: 64px;
  flex: none;
  color: var(--muted);
  font-size: 13px;
}

.bench-track {
  flex: 1;
  background: var(--code-bg);
  border: 1px solid var(--border);
  height: 26px;
}

.bench-fill {
  background: var(--fg);
  height: 100%;
  transition: width 900ms ease;
}

.bench-value {
  width: 68px;
  flex: none;
  text-align: right;
  font-weight: 600;
  font-size: 13px;
}

.feature-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  margin-bottom: 20px;
}

.feature {
  display: flex;
  gap: 14px;
  padding: 8px;
  margin: -8px;
  transition: transform 150ms ease, background 150ms ease;
}

.feature:hover {
  transform: translateY(-2px);
  background: var(--code-bg);
}

.feature .icon {
  flex: none;
  width: 28px;
  height: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--border);
}

.feature .icon svg {
  width: 16px;
  height: 16px;
}

.feature h3 {
  margin: 2px 0 4px;
}

.feature p {
  margin: 0;
  color: var(--muted);
}

.demo-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 12px;
}

.demo-tabs button {
  font: inherit;
  background: var(--bg);
  color: var(--muted);
  border: 1px solid var(--border);
  padding: 6px 14px;
  cursor: pointer;
  transition: background 150ms ease, color 150ms ease, border-color 150ms ease;
}

.demo-tabs button[aria-selected="true"] {
  background: var(--fg);
  color: var(--bg);
  border-color: var(--fg);
}

.demo-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--muted);
  font-size: 12px;
  margin-bottom: 16px;
}

.demo-badge .dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--muted);
}

.demo-note {
  color: var(--muted);
  font-size: 12px;
  font-style: italic;
}

.live-graph {
  display: none;
  width: 100%;
  height: 72px;
  border: 1px solid var(--border);
  margin-bottom: 12px;
}

.live-graph.visible {
  display: block;
}

.page-nav {
  display: flex;
  justify-content: space-between;
  margin-top: 56px;
  padding-top: 24px;
  border-top: 1px solid var(--border);
  font-size: 13px;
}

.page-nav a {
  text-decoration: none;
  color: var(--muted);
}

.page-nav a:hover {
  color: var(--fg);
}

.page-nav .next {
  text-align: right;
}

.page-nav .dir {
  display: block;
  color: var(--muted);
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

footer {
  border-top: 1px solid var(--border);
}

.footer-inner {
  max-width: 760px;
  margin: 0 auto;
  padding: 24px;
  color: var(--muted);
  font-size: 12px;
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 8px;
}

footer a {
  color: var(--muted);
}

#demo-code.idle::after {
  content: '\258B';
  display: inline-block;
  margin-left: 2px;
  animation: sandbin-blink 1s step-end infinite;
}

@keyframes sandbin-blink {
  50% { opacity: 0; }
}

.reveal {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 500ms ease, transform 500ms ease;
}

.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

@media (prefers-reduced-motion: reduce) {
  .reveal {
    opacity: 1;
    transform: none;
    transition: none;
  }
  .bench-fill {
    transition: none;
  }
  #demo-code.idle::after {
    animation: none;
  }
}

@media (max-width: 600px) {
  .grid-cols-2, .feature-grid {
    grid-template-columns: 1fr;
  }
  .stat-row {
    grid-template-columns: 1fr 1fr;
    row-gap: 20px;
  }
  .topbar-inner, main, .footer-inner {
    padding-left: 16px;
    padding-right: 16px;
  }
}