:root {
  --bg: #fdfdfc;
  --fg: #1f2328;
  --muted: #6a737d;
  --accent: #0b6bcb;
  --border: #e4e4e2;
  --code-bg: #f4f4f2;
  --measure: 44rem;
}

/* Light by default; dark only when the reader picks it with the toggle */
:root[data-theme="dark"] {
  --bg: #15171a;
  --fg: #e3e5e8;
  --muted: #9aa2ab;
  --accent: #6cb4ff;
  --border: #2c3036;
  --code-bg: #1e2126;
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font: 18px/1.65 Charter, "Bitstream Charter", "Sitka Text", Cambria, Georgia, serif;
}

.site-header, main, .site-footer {
  max-width: var(--measure);
  margin: 0 auto;
  padding: 0 1rem;
}

.site-header {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: baseline;
  gap: .5rem 1.5rem;
  padding-top: 2rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--border);
  font-family: system-ui, -apple-system, "Segoe UI", sans-serif;
}

.site-title { font-weight: 700; font-size: 1.1rem; color: var(--fg); }
.site-header nav { display: flex; gap: 1.1rem; font-size: .95rem; }
.site-header nav a { color: var(--muted); }
.site-header nav a:hover { color: var(--accent); }
.theme-toggle {
  background: none;
  border: 0;
  padding: 0;
  font: inherit;
  color: var(--muted);
  cursor: pointer;
}
.theme-toggle:hover { color: var(--accent); }

main { padding-top: 2rem; padding-bottom: 3rem; }

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

h1, h2, h3, h4 {
  font-family: system-ui, -apple-system, "Segoe UI", sans-serif;
  line-height: 1.25;
  margin: 2em 0 .6em;
}
h1 { font-size: 2rem; margin-top: 0; }
h2 { font-size: 1.45rem; }
h3 { font-size: 1.15rem; }

/* Home */
.intro { color: var(--muted); margin-bottom: 1rem; }
.year h2 { font-size: 1rem; color: var(--muted); margin: 2rem 0 .5rem; }
.post-list { list-style: none; padding: 0; margin: 0; }
.post-list li {
  display: grid;
  grid-template-columns: 4.5rem 1fr;
  gap: 1rem;
  padding: .35rem 0;
}
.post-list time {
  color: var(--muted);
  font: .9rem/1.9 ui-monospace, SFMono-Regular, Menlo, monospace;
}
.post-list p { margin: .1rem 0 0; color: var(--muted); font-size: .95rem; }

/* Posts */
.post-header { margin-bottom: 2rem; }
.post-meta { color: var(--muted); font-size: .95rem; margin: .3rem 0 0; }
.post-content img, .post-content video {
  display: block;
  max-width: 100%;
  height: auto;
  margin: 1.5rem auto .5rem;
  border-radius: 4px;
}
.post-content .caption {
  text-align: center;
  color: var(--muted);
  font-size: .9rem;
  margin-top: 0;
}
.post-content .side-by-side {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
}
.post-content .side-by-side img { width: 14rem; margin: 0; }
.post-content blockquote {
  margin: 1.5rem 0;
  padding: 0 1rem;
  border-left: 3px solid var(--border);
  color: var(--muted);
}
.post-content table { border-collapse: collapse; margin: 1.5rem 0; }
.post-content th, .post-content td { border: 1px solid var(--border); padding: .35rem .7rem; }
.back { margin-top: 3rem; font-size: .95rem; }

/* Math: long display equations scroll instead of overflowing on phones */
mjx-container[display="true"] {
  overflow-x: auto;
  overflow-y: hidden;
  padding: .25rem 0;
}

/* Code */
code, pre {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: .85em;
}
:not(pre) > code {
  background: var(--code-bg);
  padding: .1em .35em;
  border-radius: 4px;
}
pre {
  background: var(--code-bg);
  padding: 1rem;
  overflow-x: auto;
  border-radius: 6px;
  line-height: 1.5;
}

/* Rouge syntax highlighting (light + dark) */
.highlight .c, .highlight .c1, .highlight .cm, .highlight .cs { color: #6a737d; font-style: italic; }
.highlight .k, .highlight .kd, .highlight .kn, .highlight .kr, .highlight .kt { color: #cf222e; }
.highlight .s, .highlight .s1, .highlight .s2, .highlight .sc { color: #0a3069; }
.highlight .m, .highlight .mi, .highlight .mf, .highlight .mh { color: #0550ae; }
.highlight .nf, .highlight .nx { color: #8250df; }
.highlight .nc, .highlight .nn { color: #953800; }
.highlight .o, .highlight .ow { color: #cf222e; }
.highlight .cp { color: #cf222e; }
[data-theme="dark"] .highlight .c, [data-theme="dark"] .highlight .c1,
[data-theme="dark"] .highlight .cm, [data-theme="dark"] .highlight .cs { color: #8b949e; }
[data-theme="dark"] .highlight .k, [data-theme="dark"] .highlight .kd,
[data-theme="dark"] .highlight .kn, [data-theme="dark"] .highlight .kr,
[data-theme="dark"] .highlight .kt, [data-theme="dark"] .highlight .o,
[data-theme="dark"] .highlight .ow, [data-theme="dark"] .highlight .cp { color: #ff7b72; }
[data-theme="dark"] .highlight .s, [data-theme="dark"] .highlight .s1,
[data-theme="dark"] .highlight .s2, [data-theme="dark"] .highlight .sc { color: #a5d6ff; }
[data-theme="dark"] .highlight .m, [data-theme="dark"] .highlight .mi,
[data-theme="dark"] .highlight .mf, [data-theme="dark"] .highlight .mh { color: #79c0ff; }
[data-theme="dark"] .highlight .nf, [data-theme="dark"] .highlight .nx { color: #d2a8ff; }
[data-theme="dark"] .highlight .nc, [data-theme="dark"] .highlight .nn { color: #ffa657; }

.site-footer {
  display: flex;
  justify-content: space-between;
  padding-top: 1.5rem;
  padding-bottom: 2.5rem;
  border-top: 1px solid var(--border);
  color: var(--muted);
  font: .9rem system-ui, -apple-system, sans-serif;
}