/* ---- Design tokens ---- */
:root {
  --paper: #f0f1ed;
  --paper-raised: #ffffff;
  --ink: #1b1d1b;
  --ink-soft: #5b5f5a;
  --ink-faint: #8a8d86;
  --line: #dadcd4;
  --signal: #2b6e5e;
  --signal-soft: #ddeae4;
  --signal-text: #1e4f43;

  --font-display: "Fraunces", Georgia, serif;
  --font-mono: "IBM Plex Mono", ui-monospace, monospace;
  --font-body: "Inter", -apple-system, "Segoe UI", sans-serif;

  --measure: 640px;
  --radius: 10px;
}

html[data-theme="dark"] {
  --paper: #14160f;
  --paper-raised: #1c1f18;
  --ink: #ededea;
  --ink-soft: #a4a89b;
  --ink-faint: #6d7166;
  --line: #2c2f26;
  --signal: #6fcbae;
  --signal-soft: #1c2e28;
  --signal-text: #8fe0c4;
}

* { box-sizing: border-box; }

html { color-scheme: light; }
html[data-theme="dark"] { color-scheme: dark; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.6;
  transition: background .2s ease, color .2s ease;
}

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

img { max-width: 100%; }

/* ---- Layout ---- */
.wrap {
  max-width: 880px;
  margin: 0 auto;
  padding: 0 24px;
}

.site-header {
  border-bottom: 1px solid var(--line);
}

.site-header .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 22px;
  padding-bottom: 22px;
}

.brand {
  display: flex;
  align-items: baseline;
  gap: 10px;
}

.brand .name {
  font-family: var(--font-display);
  font-size: 22px;
  font-weight: 600;
  color: var(--ink);
}

.brand .tagline {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--ink-faint);
  letter-spacing: 0.02em;
}

.nav {
  display: flex;
  align-items: center;
  gap: 22px;
}

.nav a {
  color: var(--ink-soft);
  font-size: 14px;
}
.nav a:hover { color: var(--ink); text-decoration: none; }

.theme-toggle {
  width: 34px;
  height: 34px;
  border-radius: 50%;
  border: 1px solid var(--line);
  background: var(--paper-raised);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  color: var(--ink-soft);
}
.theme-toggle:hover { border-color: var(--ink-faint); }

/* ---- Signal trace signature element ---- */
.signal-trace {
  width: 100%;
  height: 28px;
  display: block;
  margin: 0;
}
.signal-trace path {
  fill: none;
  stroke: var(--signal);
  stroke-width: 1.5;
  opacity: 0.55;
}

/* ---- Hero ---- */
.hero {
  padding: 56px 0 36px;
}
.hero h1 {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 34px;
  line-height: 1.3;
  max-width: 560px;
  margin: 0 0 14px;
}
.hero p {
  max-width: 520px;
  color: var(--ink-soft);
  font-size: 15px;
  margin: 0;
}

/* ---- Article cards ---- */
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 20px;
  padding: 8px 0 48px;
}

.card {
  background: var(--paper-raised);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--signal-text);
  background: var(--signal-soft);
  padding: 3px 10px;
  border-radius: 20px;
  width: fit-content;
}

.card h3 {
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 600;
  margin: 0;
  line-height: 1.4;
}

.card p {
  color: var(--ink-soft);
  font-size: 14px;
  margin: 0;
  flex-grow: 1;
}

.meta {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--ink-faint);
}

/* ---- Article page ---- */
.article-header {
  padding: 48px 0 8px;
}
.article-header .tag { margin-bottom: 18px; }
.article-header h1 {
  font-family: var(--font-display);
  font-size: 32px;
  line-height: 1.35;
  margin: 0 0 14px;
}
.article-body {
  max-width: var(--measure);
  padding-bottom: 64px;
  font-size: 17px;
}
.article-body p { margin: 0 0 20px; }
.article-body h2 {
  font-family: var(--font-display);
  font-size: 21px;
  margin: 36px 0 14px;
}
.article-body blockquote {
  border-left: 2px solid var(--signal);
  margin: 24px 0;
  padding-left: 18px;
  color: var(--ink-soft);
  font-family: var(--font-display);
  font-style: italic;
}

/* ---- Footer ---- */
.site-footer {
  border-top: 1px solid var(--line);
  padding: 28px 0;
  font-size: 13px;
  color: var(--ink-faint);
}
.site-footer .wrap {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

/* ---- Focus & motion ---- */
a:focus-visible, button:focus-visible {
  outline: 2px solid var(--signal);
  outline-offset: 2px;
}
@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; }
}

@media (max-width: 560px) {
  .hero h1 { font-size: 27px; }
  .nav { gap: 14px; }
  .site-header .wrap { flex-wrap: wrap; gap: 12px; }
}