:root {
  --color-bg: #fafafa;
  --color-text: #222;
  --color-muted: #666;
  --color-border: #ddd;
  --color-link: #1a56db;
  --color-code-bg: #f0f0f0;
  --color-table-border: #ccc;
  --color-callout-tldr-bg: #eef6ff;
  --color-callout-tldr-border: #4a9eff;
  --color-callout-idea-bg: #eef6ff;
  --color-callout-idea-border: #f5c542;
  --color-blockquote-bg: #fff;
  --color-blockquote-border: #ccc;
  --color-blockquote-text: #444;
  --color-tbd-bg: #fff3cd;
  --color-tbd-border: #ffc107;
}

@media (prefers-color-scheme: dark) {
  :root {
    --color-bg: #1a1a1a;
    --color-text: #e0e0e0;
    --color-muted: #999;
    --color-border: #3a3a3a;
    --color-link: #7aa2ff;
    --color-code-bg: #2a2a2a;
    --color-table-border: #444;
    --color-callout-tldr-bg: #17263f;
    --color-callout-tldr-border: #4a9eff;
    --color-callout-idea-bg: #2b2410;
    --color-callout-idea-border: #f5c542;
    --color-blockquote-bg: #232323;
    --color-blockquote-border: #4a4a4a;
    --color-blockquote-text: #bbb;
    --color-tbd-bg: #332b0a;
    --color-tbd-border: #ffc107;
  }
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  line-height: 1.7;
  max-width: 720px;
  margin: 0 auto;
  padding: 2rem 1rem;
  color: var(--color-text);
  background: var(--color-bg);
}
a, a:visited {
  color: var(--color-link);
  text-decoration: none;
}
a:hover {
  text-decoration: underline;
}
h1 {
  font-size: 1.8rem;
  margin-bottom: 0.2rem;
}
h2 {
  margin-top: 2.5rem;
  font-size: 1.4rem;
  border-bottom: 1px solid var(--color-border);
  padding-bottom: 0.3rem;
}
h3 {
  margin-top: 2rem;
  font-size: 1.15rem;
}
.meta {
  color: var(--color-muted);
  font-size: 0.9rem;
  margin-bottom: 2rem;
}
.callout {
  padding: 0.8rem 1rem;
  margin: 1.5rem 0;
  font-size: 0.95rem;
}
.callout-tldr {
  background: var(--color-callout-tldr-bg);
  border-left: 4px solid var(--color-callout-tldr-border);
}
.callout-idea {
  background: var(--color-callout-idea-bg);
  border-left: 4px solid var(--color-callout-idea-border);
}
figure {
  margin: 1.5rem 0;
  text-align: center;
}
figure img {
  max-width: 100%;
  height: auto;
}
@media (prefers-color-scheme: dark) {
  /* Figures are black line art on transparent backgrounds; invert so they stay visible. */
  figure img {
    filter: invert(1);
  }
}
figcaption {
  font-size: 0.85rem;
  color: var(--color-muted);
  margin-top: 0.5rem;
}
table {
  border-collapse: collapse;
  margin: 1rem auto;
  font-size: 0.9rem;
}
th, td {
  border: 1px solid var(--color-table-border);
  padding: 0.4rem 0.7rem;
  text-align: center;
}
th {
  background: var(--color-code-bg);
}
.tbd {
  background: var(--color-tbd-bg);
  border: 1px dashed var(--color-tbd-border);
  padding: 1rem;
  margin: 1.5rem 0;
  font-style: italic;
}
code {
  background: var(--color-code-bg);
  padding: 0.1rem 0.3rem;
  border-radius: 3px;
  font-size: 0.9em;
}
pre {
  background: var(--color-code-bg);
  padding: 1rem;
  overflow-x: auto;
  border-radius: 4px;
  font-size: 0.9em;
}
pre code {
  background: none;
  padding: 0;
}
blockquote {
  margin: 1.5rem 0;
  padding: 0.8rem 1rem;
  background: var(--color-blockquote-bg);
  border-left: 4px solid var(--color-blockquote-border);
  color: var(--color-blockquote-text);
  font-size: 0.95rem;
}
.footnote {
  font-size: 0.85rem;
  color: var(--color-muted);
}

/* Index page */
ul.posts {
  list-style: none;
  padding: 0;
}
ul.posts li {
  margin: 1.3rem 0;
}
ul.posts .title {
  font-size: 1.3rem;
}
ul.posts .date {
  display: block;
  color: var(--color-muted);
  font-size: 0.85rem;
  margin-top: 0.2rem;
}