:root {
  --bg: #0a0a0b;
  --ink: #ececee;
  --muted: #8a8d94;
  --faint: #565961;
  --line: rgba(255, 255, 255, 0.08);
  --line-strong: rgba(255, 255, 255, 0.18);
  --panel: rgba(255, 255, 255, 0.03);
  --red: #ef2532;
  --amber: #f5c518;
  --body: "Inter", system-ui, -apple-system, "Segoe UI", sans-serif;
  --mono: "JetBrains Mono", ui-monospace, monospace;
}
* {
  box-sizing: border-box;
}
html {
  scroll-behavior: smooth;
}
html,
body {
  margin: 0;
}
body {
  background: var(--bg);
  color: var(--ink);
  font-family: var(--body);
  line-height: 1.65;
  letter-spacing: -0.006em;
  -webkit-font-smoothing: antialiased;
}
.wrap {
  width: 100%;
  max-width: 820px;
  margin: 0 auto;
  padding: 0 2rem;
}

/* Nav */
nav.bar {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(10, 10, 11, 0.9);
  border-bottom: 1px solid var(--line);
}
nav.bar .inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
  gap: 1rem;
}
.brand-logo {
  height: 40px;
  width: auto;
  display: block;
}
.back {
  color: var(--muted);
  text-decoration: none;
  font-size: 0.9rem;
  white-space: nowrap;
}
.back:hover {
  color: var(--ink);
}

/* Header */
main {
  padding: 3rem 0 4rem;
}
h1 {
  font-size: clamp(1.9rem, 4.5vw, 2.6rem);
  letter-spacing: -0.03em;
  margin: 0 0 0.75rem;
}
.lead {
  color: var(--muted);
  font-size: 1.08rem;
  margin: 0 0 2.5rem;
}
h2 {
  font-size: 1.35rem;
  letter-spacing: -0.015em;
  margin: 3rem 0 0.9rem;
  padding-top: 1.75rem;
  border-top: 1px solid var(--line);
  scroll-margin-top: 84px;
}
h3 {
  font-size: 1.05rem;
  margin: 1.8rem 0 0.5rem;
}
p,
li {
  color: #c9cdd6;
}
p {
  margin: 0 0 0.9rem;
}
a {
  color: var(--red);
  word-break: break-word;
}
strong {
  color: var(--ink);
}

/* Table of contents */
.toc {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 1.25rem 1.4rem;
  margin-bottom: 1rem;
}
.toc h2 {
  font-family: var(--mono);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.16em;
  color: var(--faint);
  margin: 0 0 0.75rem;
  padding: 0;
  border: 0;
}
.toc ol {
  margin: 0;
  padding-left: 1.2rem;
  columns: 2;
  column-gap: 2rem;
}
.toc li {
  margin-bottom: 0.3rem;
  break-inside: avoid;
}
.toc a {
  color: var(--muted);
  text-decoration: none;
}
.toc a:hover {
  color: var(--ink);
}
@media (max-width: 620px) {
  .toc ol {
    columns: 1;
  }
}

/* Numbered steps */
ol.steps {
  list-style: none;
  counter-reset: step;
  margin: 0 0 1rem;
  padding: 0;
}
ol.steps > li {
  counter-increment: step;
  position: relative;
  padding-left: 2.6rem;
  margin-bottom: 1rem;
}
ol.steps > li::before {
  content: counter(step);
  position: absolute;
  left: 0;
  top: 0.05rem;
  width: 1.75rem;
  height: 1.75rem;
  border-radius: 50%;
  background: var(--panel);
  border: 1px solid var(--line-strong);
  color: var(--ink);
  font-family: var(--mono);
  font-size: 0.8rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
}
ul {
  margin: 0 0 0.9rem;
  padding-left: 1.2rem;
}
li {
  margin-bottom: 0.35rem;
}

/* Callouts */
.callout {
  border: 1px solid var(--line-strong);
  border-left: 3px solid var(--muted);
  border-radius: 10px;
  background: var(--panel);
  padding: 1rem 1.2rem;
  margin: 1.25rem 0;
}
.callout p:last-child {
  margin-bottom: 0;
}
.callout .title {
  font-weight: 600;
  color: var(--ink);
  margin-bottom: 0.35rem;
  display: block;
}
.callout--warn {
  border-left-color: var(--amber);
}
.callout--info {
  border-left-color: var(--red);
}

/* Inline bits */
kbd {
  font-family: var(--mono);
  font-size: 0.82em;
  background: var(--panel);
  border: 1px solid var(--line-strong);
  border-bottom-width: 2px;
  border-radius: 6px;
  padding: 0.1em 0.45em;
  color: var(--ink);
  white-space: nowrap;
}
code {
  font-family: var(--mono);
  font-size: 0.88em;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 0.1em 0.4em;
  color: var(--ink);
}

/* Footer */
footer {
  border-top: 1px solid var(--line);
}
footer .inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.75rem 1.25rem;
  padding-top: 2rem;
  padding-bottom: 2rem;
  color: var(--faint);
  font-size: 0.85rem;
}
.foot-links {
  display: flex;
  gap: 1.25rem;
  flex-wrap: wrap;
}
.foot-links a {
  color: var(--muted);
  text-decoration: none;
}
.foot-links a:hover {
  color: var(--ink);
}