:root {
  --bg: #0b0c0e;            /* cold rolled steel, dark */
  --panel: #121317;
  --ink: #e8e9ec;
  --muted: #969aa3;
  --line: #262932;
  --accent: #5aa9e6;        /* blueprint / weld-arc blue */
  --accent-dim: #3a7fb5;
  --rivet: #3a4350;         /* bolt heads on a steel seam */
  --measure: 44rem;
}

* { box-sizing: border-box; }

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

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font: 17px/1.65 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--accent); text-decoration: none; }
a:hover { color: var(--accent-dim); text-decoration: underline; }
code {
  font: .92em/1 ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  background: var(--panel); border: 1px solid var(--line);
  padding: .08em .35em; border-radius: 4px; color: var(--ink);
}

/* header / footer */
header.site, footer.site {
  display: flex; flex-wrap: wrap; gap: .75rem 1.25rem; align-items: baseline;
  max-width: var(--measure); margin: 0 auto; padding: 1.4rem 1.25rem;
}
header.site { justify-content: space-between; }
.brand { font-weight: 700; letter-spacing: .02em; color: var(--ink); text-transform: lowercase; }
.brand:hover { color: var(--accent); text-decoration: none; }
header.site nav { display: flex; gap: 1.1rem; }
header.site nav a { color: var(--muted); font-size: .95rem; }
header.site nav a:hover { color: var(--ink); text-decoration: none; }

/* the riveted steel seam — industrial, structural, bolted to last */
.seam {
  height: 12px;
  background:
    radial-gradient(circle at 14px 50%, var(--rivet) 0 2.4px, transparent 3px) 0 0 / 28px 12px repeat-x,
    linear-gradient(180deg, #14161b, #0e0f13);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

/* content */
main { max-width: var(--measure); margin: 0 auto; padding: 1.5rem 1.25rem 4rem; }
article h1 { font-size: 2.15rem; line-height: 1.12; margin: 1rem 0 .4rem; letter-spacing: -0.01em; }
article h2 { font-size: 1.3rem; margin: 2.4rem 0 .6rem; }
.dek { color: var(--muted); font-size: 1.15rem; margin: 0 0 1.8rem; }
p, ul, ol { margin: 0 0 1.1rem; }
ul, ol { padding-left: 1.3rem; }
li { margin: .4rem 0; }
strong { color: #fff; }

.pull {
  font-size: 1.25rem; font-weight: 600; color: var(--accent);
  border-top: 1px solid var(--line); border-bottom: 1px solid var(--line);
  padding: 1rem 0; margin: 1.8rem 0;
}

/* the two failure modes, framed like a spec sheet */
.modes { list-style: none; padding-left: 0; }
.modes li {
  border-left: 3px solid var(--line); padding: .15rem 0 .15rem 1rem; margin: .9rem 0;
}

.kicker {
  font-size: 1.3rem; font-weight: 700; color: #fff;
  margin: 2.4rem 0 0;
}

footer.site {
  border-top: 1px solid var(--line); margin-top: 2rem;
  color: var(--muted); font-size: .9rem;
}
footer.site a { color: var(--muted); }
footer.site a:hover { color: var(--accent); }

@media (max-width: 480px) {
  body { font-size: 16px; }
  article h1 { font-size: 1.75rem; }
}