:root {
  --bg: #000;
  --fg: #fff;
  --glass: rgba(0,0,0,0.45);
  --accent: #d9a4ff;
}
[data-theme="light"] {
  --bg: #f6f6f6;
  --fg: #0b0b0b;
  --glass: rgba(255,255,255,0.7);
  --accent: #7a3cff;
}

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
  background: var(--bg);
  color: var(--fg);
  line-height: 1.7;
  overflow-x: hidden;
}

nav {
  position: fixed;
  top: 0;
  width: 100%;
  display: flex;
  justify-content: space-between;
  padding: 14px 24px;
  backdrop-filter: blur(12px);
  background: var(--glass);
  z-index: 10;
  box-sizing: border-box;
}
nav .logo { font-weight: 700; letter-spacing: 0.12em; }
nav ul { display: flex; gap: 16px; list-style: none; margin: 0; padding: 0; align-items: center; }
nav li { cursor: pointer; opacity: 0.8; }
nav li:hover { opacity: 1; }
nav a { color: inherit; text-decoration: none; }

main {
  max-width: 860px;
  margin: 140px auto 80px;
  padding: 0 24px;
}

h1 { font-size: clamp(2.4rem, 5vw, 3.8rem); margin-bottom: 0.8rem; }
h2 { font-size: clamp(1.6rem, 3vw, 2.2rem); margin-top: 0; color: var(--accent); }
h3 { margin-top: 1.8rem; color: var(--accent); }
p { margin-bottom: 1.8rem; }

/* Section divider: ── ◆ ── before each section heading */
main h2::before {
  content: "◆";
  display: block;
  text-align: center;
  font-size: 0.55rem;
  color: var(--accent);
  opacity: 0.55;
  margin: 3.5rem auto 2.5rem;
  background:
    linear-gradient(90deg,
      transparent 0%, rgba(128,128,128,0.35) 20%, rgba(128,128,128,0.35) 46%, transparent 46.5%,
      transparent 53.5%, rgba(128,128,128,0.35) 54%, rgba(128,128,128,0.35) 80%, transparent 100%)
    center / min(340px, 70%) 1px no-repeat;
}
code { background: rgba(255,255,255,0.08); padding: 2px 6px; border-radius: 6px; }
pre { background: rgba(255,255,255,0.08); padding: 16px; border-radius: 12px; overflow-x: auto; }
[data-theme="light"] pre { background: rgba(0,0,0,0.06); }
[data-theme="light"] code { background: rgba(0,0,0,0.06); }

pre.mermaid {
  background: none;
  display: flex;
  justify-content: center;
  margin: 2.2rem 0;
  overflow-x: auto;
}
pre.mermaid svg { max-width: 100%; height: auto; }
blockquote { border-left: 4px solid var(--accent); padding-left: 12px; opacity: 0.8; margin: 1.5rem 0; }

footer { text-align: center; padding: 48px 24px; opacity: 0.6; }

button.toggle {
  background: none;
  border: 1px solid currentColor;
  color: inherit;
  padding: 6px 12px;
  border-radius: 999px;
  cursor: pointer;
  font-size: 0.75rem;
}
button.toggle:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

/* Pull-quote: the one line skimmers should catch */
blockquote.pullquote {
  border-left: none;
  margin: 3rem auto;
  padding: 0 24px;
  max-width: 620px;
  text-align: center;
  font-size: 1.35rem;
  font-style: italic;
  line-height: 1.5;
  opacity: 1;
  color: var(--fg);
}
blockquote.pullquote::before,
blockquote.pullquote::after {
  content: "◆";
  display: block;
  font-size: 0.5rem;
  font-style: normal;
  color: var(--accent);
  opacity: 0.6;
  margin: 14px auto;
}

/* Syntax highlighting palette (highlight.js classes, site-native colors) */
.hljs-comment, .hljs-quote { color: #7d8590; font-style: italic; }
.hljs-keyword, .hljs-selector-tag, .hljs-literal, .hljs-built_in { color: #d9a4ff; }
.hljs-string, .hljs-regexp, .hljs-addition { color: #7ee787; }
.hljs-number, .hljs-symbol, .hljs-bullet { color: #79c0ff; }
.hljs-title, .hljs-section, .hljs-name, .hljs-function .hljs-title { color: #ffa657; }
.hljs-attr, .hljs-attribute, .hljs-variable, .hljs-template-variable, .hljs-params { color: #ffd28e; }
.hljs-meta, .hljs-deletion { color: #ff7b72; }
[data-theme="light"] .hljs-comment, [data-theme="light"] .hljs-quote { color: #6e7781; }
[data-theme="light"] .hljs-keyword, [data-theme="light"] .hljs-selector-tag, [data-theme="light"] .hljs-literal, [data-theme="light"] .hljs-built_in { color: #7a3cff; }
[data-theme="light"] .hljs-string, [data-theme="light"] .hljs-regexp, [data-theme="light"] .hljs-addition { color: #0a7d33; }
[data-theme="light"] .hljs-number, [data-theme="light"] .hljs-symbol, [data-theme="light"] .hljs-bullet { color: #0550ae; }
[data-theme="light"] .hljs-title, [data-theme="light"] .hljs-section, [data-theme="light"] .hljs-name { color: #b35900; }
[data-theme="light"] .hljs-attr, [data-theme="light"] .hljs-attribute, [data-theme="light"] .hljs-variable, [data-theme="light"] .hljs-template-variable, [data-theme="light"] .hljs-params { color: #8a5a00; }
[data-theme="light"] .hljs-meta, [data-theme="light"] .hljs-deletion { color: #cf222e; }

/* Copy button on code blocks */
pre { position: relative; }
.copy-btn {
  position: absolute;
  top: 8px;
  right: 8px;
  padding: 4px 12px;
  font-size: 0.72rem;
  font-family: inherit;
  border-radius: 999px;
  border: 1px solid rgba(128,128,128,0.4);
  background: var(--bg);
  color: var(--fg);
  cursor: pointer;
  opacity: 0;
  transition: opacity 0.15s;
}
pre:hover .copy-btn, .copy-btn:focus-visible { opacity: 0.85; }
.copy-btn:hover { opacity: 1; border-color: var(--accent); }

/* Reading progress bar */
.progress-bar {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  width: 0;
  background: linear-gradient(90deg, var(--accent), #00ffaa);
  z-index: 20;
  pointer-events: none;
}

/* Prev/next post navigation */
.post-nav {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin: 4rem 0 1rem;
}
.post-nav a {
  display: block;
  padding: 18px 20px;
  border: 1px solid rgba(128,128,128,0.3);
  border-radius: 14px;
  text-decoration: none;
  color: inherit;
  transition: border-color 0.2s, transform 0.2s;
}
.post-nav a:hover { border-color: var(--accent); transform: translateY(-2px); }
.post-nav a.next { text-align: right; grid-column: 2; }
.post-nav .post-nav-label { display: block; font-size: 0.72rem; text-transform: uppercase; letter-spacing: 0.08em; opacity: 0.55; margin-bottom: 6px; }
.post-nav .post-nav-title { font-weight: 600; font-size: 0.95rem; line-height: 1.4; }
@media (max-width: 560px) {
  .post-nav { grid-template-columns: 1fr; }
  .post-nav a.next { grid-column: auto; }
}

/* References */
ul.references {
  font-size: 0.88rem;
  line-height: 1.7;
  opacity: 0.85;
  padding-left: 20px;
}
ul.references li { margin-bottom: 14px; }
ul.references a { font-weight: 600; }
ul.references a { color: var(--accent); text-decoration: none; }
ul.references a:hover { text-decoration: underline; }

/* Evidence figures */
figure {
  margin: 2.5rem 0;
  text-align: center;
}
figure img {
  max-width: 100%;
  border-radius: 14px;
  border: 1px solid rgba(128,128,128,0.3);
}
figcaption {
  margin-top: 10px;
  font-size: 0.85rem;
  opacity: 0.6;
}

.playground-callout {
  border: 1px solid var(--accent);
  border-radius: 14px;
  padding: 18px 22px;
  margin: 2.5rem 0;
  background: rgba(217,164,255,0.05);
}
[data-theme="light"] .playground-callout {
  background: rgba(122,60,255,0.05);
}
.playground-callout .pc-label {
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--accent);
  margin-bottom: 6px;
  margin-top: 0;
}
.playground-callout p:last-child { margin-bottom: 0; }
.playground-callout a { color: var(--accent); font-weight: 600; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .post-nav a:hover { transform: none; }
}