@import url('https://fonts.googleapis.com/css2?family=Fraunces:opsz,wght@9..144,600;9..144,700&family=Inter:wght@400;600;700&display=swap');

:root {
  --paper: #FEFCF6;
  --surface: #FFFFFF;
  --surface-2: #EDE6D6;
  --ink: #2A2418;
  --muted: #6B6353;
  --line: #DDD4C0;
  --accent: #0E6B6A;
  --accent-strong: #0A4F4E;
  --accent-soft: #DCEAE7;
  --amber: #B0812B;
  --ok: #2E7D46;
  --shadow: 0 1px 2px rgba(42,36,24,.05), 0 8px 24px rgba(42,36,24,.06);
  --serif: 'Fraunces', Georgia, 'Times New Roman', serif;
  --sans: 'Inter', 'Segoe UI', system-ui, -apple-system, 'Helvetica Neue', sans-serif;
  --mono: Consolas, 'SF Mono', ui-monospace, Menlo, monospace;
}
@media (prefers-color-scheme: dark) {
  :root {
    --paper: #0C1514; --surface: #121F1E; --surface-2: #182927;
    --ink: #E3EFEC; --muted: #8FA8A3; --line: #243835;
    --accent: #3BC9BE; --accent-strong: #5CD8CE; --accent-soft: #143430;
    --amber: #E0A23F; --ok: #57B876;
    --shadow: 0 1px 2px rgba(0,0,0,.3), 0 8px 24px rgba(0,0,0,.25);
  }
}

* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}
.wrap { max-width: 760px; margin: 0 auto; padding: 0 24px; }
.wrap-wide { max-width: 1080px; margin: 0 auto; padding: 0 24px; }
a { color: var(--accent); }
a:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

/* header / footer (match homepage) */
header.site {
  border-bottom: 1px solid var(--line);
  background: color-mix(in srgb, var(--paper) 88%, transparent);
  position: sticky; top: 0; z-index: 20;
  backdrop-filter: blur(8px);
}
.site-inner { display: flex; align-items: center; justify-content: space-between; gap: 16px; padding-top: 14px; padding-bottom: 14px; }
.wordmark {
  font-family: var(--serif); font-size: 1.45rem; letter-spacing: -0.01em;
  color: var(--ink); text-decoration: none; font-weight: 700;
  display: flex; align-items: center; gap: 10px;
}
.wordmark em { font-style: normal; color: var(--accent); }
.logo-mark { width: 32px; height: 32px; flex-shrink: 0; display: block; }
nav.tools-nav { display: flex; gap: 22px; align-items: center; }
nav.tools-nav a { color: var(--muted); text-decoration: none; font-size: .92rem; }
nav.tools-nav a:hover { color: var(--ink); }
.btn {
  display: inline-block; background: var(--accent); color: var(--paper);
  border: none; border-radius: 999px; padding: 9px 20px;
  font-family: var(--sans); font-size: .92rem; font-weight: 600;
  text-decoration: none; cursor: pointer;
}
.btn:hover { background: var(--accent-strong); }
nav.tools-nav a.btn, nav.tools-nav a.btn:hover { color: var(--paper); }
@media (max-width: 640px) { nav.tools-nav .navlink { display: none; } }

footer.site {
  border-top: 1px solid var(--line);
  padding: 30px 0 40px; color: var(--muted); font-size: .86rem;
  margin-top: 64px;
}
.footer-inner { display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; }

/* article */
.eyebrow {
  font-size: .72rem; font-weight: 700; letter-spacing: .14em;
  text-transform: uppercase; color: var(--accent); margin: 0 0 14px;
}
.eyebrow .sep { color: var(--amber); }
article { padding: 56px 0 20px; }
article h1 {
  font-family: var(--serif);
  font-size: clamp(1.9rem, 4.2vw, 2.7rem);
  line-height: 1.15; letter-spacing: -0.015em;
  margin: 0 0 16px; text-wrap: balance; font-weight: 700;
}
.lede { color: var(--muted); font-size: 1.1rem; margin: 0 0 32px; }
article h2 {
  font-family: var(--serif);
  font-size: 1.45rem; letter-spacing: -0.01em;
  margin: 40px 0 12px; font-weight: 700; text-wrap: balance;
}
article h3 { font-size: 1.05rem; margin: 26px 0 8px; }
article p { margin: 0 0 16px; }
article ul, article ol { margin: 0 0 16px; padding-left: 24px; }
article li { margin-bottom: 6px; }
code, .formula {
  font-family: var(--mono); font-size: .88em;
  background: var(--surface-2); border: 1px solid var(--line);
  border-radius: 5px; padding: 1px 6px;
}
.formula-block {
  font-family: var(--mono); font-size: .95rem;
  background: var(--surface-2); border: 1px solid var(--line);
  border-radius: 8px; padding: 14px 18px; margin: 0 0 16px;
  overflow-x: auto;
}

/* tables */
.table-scroll { overflow-x: auto; margin: 0 0 16px; }
table.guide {
  border-collapse: collapse; width: 100%;
  font-size: .93rem; background: var(--surface);
  border: 1px solid var(--line); border-radius: 8px; overflow: hidden;
}
table.guide th, table.guide td {
  text-align: left; padding: 10px 14px;
  border-bottom: 1px solid var(--line);
}
table.guide th {
  font-size: .72rem; text-transform: uppercase; letter-spacing: .1em;
  color: var(--muted); background: var(--surface-2);
}
table.guide tr:last-child td { border-bottom: none; }
table.guide td.num { font-family: var(--mono); font-variant-numeric: tabular-nums; }

/* callouts */
.tip {
  background: var(--accent-soft);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 14px 18px;
  margin: 0 0 16px;
  font-size: .95rem;
}
.tip strong:first-child { color: var(--accent-strong); }

.tool-cta {
  background: var(--surface);
  border: 1px solid var(--line);
  border-left: 4px solid var(--accent);
  border-radius: 0 10px 10px 0;
  box-shadow: var(--shadow);
  padding: 22px 24px;
  margin: 36px 0;
}
.tool-cta h2, .tool-cta h3 { margin: 0 0 6px; font-family: var(--serif); font-size: 1.2rem; }
.tool-cta p { margin: 0 0 14px; color: var(--muted); font-size: .95rem; }

/* related guides */
.related { border-top: 1px solid var(--line); padding-top: 24px; margin-top: 44px; }
.related h2 { font-family: var(--serif); font-size: 1.15rem; margin: 0 0 12px; }
.related ul { list-style: none; padding: 0; margin: 0; }
.related li { margin-bottom: 8px; }

/* guides index */
.guide-list { display: flex; flex-direction: column; gap: 18px; padding: 8px 0 20px; }
.guide-card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 10px;
  box-shadow: var(--shadow);
  padding: 24px 26px;
}
.guide-card h2 { font-family: var(--serif); font-size: 1.3rem; margin: 0 0 6px; }
.guide-card h2 a { color: var(--ink); text-decoration: none; }
.guide-card h2 a:hover { color: var(--accent); }
.guide-card p { margin: 0; color: var(--muted); font-size: .95rem; }
.guide-card .meta { font-size: .78rem; color: var(--muted); text-transform: uppercase; letter-spacing: .1em; margin-top: 10px; display: block; }