:root {
  --bg: #0a0e14;
  --bg-card: #121826;
  --bg-code: #0d1320;
  --line: rgba(148, 163, 196, 0.14);
  --text: #e6ebf4;
  --text-dim: #9aa6bd;
  --text-faint: #6b7690;
  --accent: #5eead4;
  --accent-2: #818cf8;
  --glow: rgba(94, 234, 212, 0.35);
  --font-sans: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-mono: ui-monospace, "SF Mono", SFMono-Regular, Menlo, Consolas, monospace;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  font-size: 18px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}
::selection { background: rgba(94, 234, 212, 0.25); }

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; text-underline-offset: 3px; }

/* Reading-progress bar */
.progress-track {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: 3px;
  z-index: 100;
  background: transparent;
}
.progress-bar {
  display: block;
  height: 100%;
  width: 0;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  box-shadow: 0 0 10px var(--glow);
  transition: width 0.08s linear;
}

/* Back link */
.article-nav {
  max-width: 760px;
  margin: 0 auto;
  padding: 40px 24px 0;
}
.back-link {
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--text-dim);
  display: inline-flex;
  align-items: center;
  gap: 8px;
  transition: color 0.2s ease, gap 0.2s ease;
}
.back-link:hover { color: var(--accent); gap: 12px; text-decoration: none; }

/* Article shell */
.article {
  max-width: 760px;
  margin: 0 auto;
  padding: 28px 24px 120px;
}
.article-kicker {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--accent);
  text-transform: uppercase;
  margin-bottom: 18px;
}
.article-title {
  font-size: clamp(32px, 5.5vw, 52px);
  line-height: 1.1;
  font-weight: 700;
  letter-spacing: -0.03em;
  margin-bottom: 18px;
}
.article-title code {
  font-family: var(--font-mono);
  font-size: 0.82em;
  background: var(--bg-code);
  border: 1px solid var(--line);
  padding: 2px 10px;
  border-radius: 8px;
  letter-spacing: 0;
}
.article-meta {
  display: flex;
  align-items: center;
  gap: 14px;
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--text-faint);
  padding-bottom: 36px;
  margin-bottom: 44px;
  border-bottom: 1px solid var(--line);
}
.article-meta .dot { color: var(--accent); }

/* Prose */
.prose > * + * { margin-top: 26px; }
.prose p { color: var(--text-dim); }
.prose strong { color: var(--text); font-weight: 650; }
.prose em { color: var(--text); }
.prose a { border-bottom: 1px solid rgba(94, 234, 212, 0.3); }
.prose a:hover { text-decoration: none; border-bottom-color: var(--accent); }

.prose h2 {
  font-size: 28px;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--text);
  margin-top: 56px;
  padding-top: 8px;
}
.prose h3 {
  font-size: 22px;
  font-weight: 650;
  letter-spacing: -0.01em;
  color: var(--text);
  margin-top: 44px;
}
.prose h2 + p, .prose h3 + p { margin-top: 16px; }

.prose ol, .prose ul { color: var(--text-dim); padding-left: 26px; }
.prose li + li { margin-top: 10px; }
.prose li p { margin-top: 0; }

/* Inline code */
.prose code {
  font-family: var(--font-mono);
  font-size: 0.86em;
  background: rgba(94, 234, 212, 0.08);
  color: #9df0e2;
  padding: 2px 7px;
  border-radius: 6px;
  border: 1px solid rgba(94, 234, 212, 0.14);
}

/* Code blocks */
.prose pre {
  background: var(--bg-code);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 20px 22px;
  overflow-x: auto;
  font-size: 14.5px;
  line-height: 1.6;
}
.prose pre code {
  font-family: var(--font-mono);
  background: none;
  border: none;
  padding: 0;
  color: #cbd5e8;
  font-size: inherit;
}

/* Blockquotes — used for the tutorial's side-notes */
.prose blockquote {
  border-left: 3px solid var(--accent);
  background: rgba(94, 234, 212, 0.05);
  border-radius: 0 10px 10px 0;
  padding: 4px 22px;
  margin-top: 26px;
}
.prose blockquote p { color: var(--text-dim); }

/* Figures / images */
.prose figure { margin-top: 32px; }
.prose img {
  display: block;
  max-width: 100%;
  height: auto;
  margin: 0 auto;
  border-radius: 12px;
  background: #fff;
  border: 1px solid var(--line);
}
.prose figcaption {
  margin-top: 12px;
  text-align: center;
  font-size: 14px;
  color: var(--text-faint);
  font-style: italic;
}
/* A dropped/removed diagram from the original post */
.figure-missing {
  margin-top: 32px;
  padding: 22px;
  border: 1px dashed var(--line);
  border-radius: 12px;
  text-align: center;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--text-faint);
  background: rgba(255,255,255,0.015);
}

/* Cross-post footer */
.article-more {
  max-width: 760px;
  margin: 0 auto;
  padding: 0 24px 100px;
}
.article-more-inner {
  border-top: 1px solid var(--line);
  padding-top: 40px;
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  justify-content: space-between;
  align-items: center;
}
.next-read {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--text-faint);
  letter-spacing: 0.04em;
  text-transform: uppercase;
  margin-bottom: 4px;
}
.next-title { font-size: 18px; font-weight: 650; color: var(--text); }
.next-title:hover { color: var(--accent); text-decoration: none; }
.article-more a.next-link { display: block; }
.article-more a.next-link:hover { text-decoration: none; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { transition: none !important; }
}

@media (max-width: 600px) {
  body { font-size: 17px; }
  .prose h2 { font-size: 24px; }
  .prose h3 { font-size: 20px; }
}