/* ============================================================
   Design system v2 — editorial / private-bank register.
   Deep navy + brushed steel, serif display, sans body.
   No monospace UI chrome, no colored status pills, no card-shadow kit.
   ============================================================ */

:root{
  --navy-950:#0D1826;
  --navy-800:#16263D;
  --navy-700:#1F3350;
  --steel-500:#66748A;
  --steel-300:#9BA8B9;
  --silver-200:#D7DDE5;
  --paper:#F6F6F4;
  --ink:#181C22;
  --ink-soft:#525A66;
  --hairline:#D9D9D4;
  --hairline-dark:rgba(255,255,255,0.16);
  --white:#FFFFFF;

  --serif:'Source Serif 4', Georgia, serif;
  --sans:'Public Sans', -apple-system, Helvetica, Arial, sans-serif;
}

*{ box-sizing:border-box; margin:0; padding:0; }
html{ scroll-behavior:smooth; }
body{
  background:var(--paper);
  color:var(--ink);
  font-family:var(--sans);
  font-size:16px;
  line-height:1.65;
  -webkit-font-smoothing:antialiased;
}
a{ color:inherit; text-decoration:none; }
a:focus-visible, button:focus-visible{ outline:2px solid var(--steel-500); outline-offset:3px; }

.container{ max-width:760px; margin:0 auto; padding:0 28px; }
.container-wide{ max-width:900px; margin:0 auto; padding:0 28px; }

h1,h2,h3{ font-family:var(--serif); font-weight:600; letter-spacing:-0.01em; }

/* ---------- Dark band (header/hero and footer — the bookend device) ---------- */
.band-dark{ background:var(--navy-950); color:var(--silver-200); }
.band-dark a{ color:var(--white); }

nav{ border-bottom:1px solid var(--hairline-dark); }
nav .container-wide{
  display:flex; align-items:center; justify-content:space-between;
  padding:20px 28px;
}
.wordmark{ font-family:var(--serif); font-size:19px; color:var(--white); font-weight:600; }
.nav-links{ display:flex; gap:28px; list-style:none; font-size:14px; }
.nav-links a{ color:var(--steel-300); transition:color .15s ease; }
.nav-links a:hover{ color:var(--white); }

/* ---------- Hero ---------- */
.hero{ padding:76px 0 84px; }
.hero .eyebrow-role{ font-size:15px; color:var(--steel-300); margin-bottom:18px; }
.hero h1{ font-size:clamp(36px, 6vw, 52px); color:var(--white); line-height:1.12; margin-bottom:22px; max-width:14ch; }
.hero p.bio{ max-width:56ch; font-size:17px; color:var(--silver-200); margin-bottom:36px; }
.hero-rule{ border:none; border-top:1px solid var(--hairline-dark); max-width:120px; margin-bottom:32px; }
.hero-actions{ display:flex; gap:16px; flex-wrap:wrap; align-items:center; }

.btn{
  display:inline-block; font-family:var(--sans); font-size:14.5px; font-weight:600;
  padding:12px 22px; border-radius:2px; border:1px solid var(--white);
  color:var(--white); background:transparent; transition:background .15s ease, color .15s ease;
}
.btn:hover{ background:var(--white); color:var(--navy-950); }
.btn-solid{ background:var(--white); color:var(--navy-950); }
.btn-solid:hover{ background:transparent; color:var(--white); }
.text-link{
  font-size:14.5px; color:var(--steel-300); border-bottom:1px solid var(--steel-500);
  padding-bottom:2px; transition:color .15s ease, border-color .15s ease;
}
.text-link:hover{ color:var(--white); border-color:var(--white); }

.section-light .text-link{ color:var(--ink-soft); border-bottom-color:var(--hairline); }
.section-light .text-link:hover{ color:var(--ink); border-color:var(--ink); }

/* ---------- Section shell (light) ---------- */
section.section-light{ padding:64px 0; border-top:1px solid var(--hairline); }
.section-head{ margin-bottom:36px; }
.section-head h2{ font-size:28px; color:var(--ink); margin-bottom:10px; }
.section-head p{ color:var(--ink-soft); max-width:56ch; font-size:15.5px; }

/* ---------- Write-ups list (editorial rows, not cards) ---------- */
.work-list{ border-top:1px solid var(--hairline); }
.work-row{ display:block; padding:22px 0; border-bottom:1px solid var(--hairline); transition:padding-left .15s ease; }
.work-row:hover{ padding-left:6px; }
.work-row .work-title{ font-family:var(--serif); font-size:19px; color:var(--ink); margin-bottom:6px; }
.work-row:hover .work-title{ text-decoration:underline; text-underline-offset:3px; }
.work-row .work-desc{ color:var(--ink-soft); font-size:15px; max-width:62ch; }
.section-footer-action{ margin-top:26px; }

/* ---------- Technical background: two-column definition rows ---------- */
.def-list{ border-top:1px solid var(--hairline); }
.def-row{ display:grid; grid-template-columns:220px 1fr; gap:24px; padding:18px 0; border-bottom:1px solid var(--hairline); }
.def-row dt{ font-weight:600; font-size:15px; color:var(--ink); }
.def-row dd{ color:var(--ink-soft); font-size:15px; }

/* ---------- Certification timeline ---------- */
.timeline{ border-left:1px solid var(--hairline); margin-left:4px; }
.tl-item{ position:relative; padding:0 0 30px 28px; }
.tl-item:last-child{ padding-bottom:0; }
.tl-item::before{ content:''; position:absolute; left:-5px; top:5px; width:9px; height:9px; background:var(--paper); border:1px solid var(--steel-500); }
.tl-item.done::before{ background:var(--navy-800); border-color:var(--navy-800); }
.tl-row{ display:flex; justify-content:space-between; align-items:baseline; gap:16px; flex-wrap:wrap; }
.tl-item h3{ font-size:17px; color:var(--ink); }
.tl-item .tl-status{ font-size:13.5px; color:var(--ink-soft); font-style:italic; white-space:nowrap; }
.tl-item p{ color:var(--ink-soft); font-size:14.5px; margin-top:4px; }

/* ---------- Footer (dark band) ---------- */
footer.band-dark{ padding:60px 0 40px; }
.footer-head h2{ color:var(--white); font-size:26px; margin-bottom:14px; }
.footer-head p{ color:var(--silver-200); max-width:50ch; margin-bottom:28px; font-size:15.5px; }
.footer-links{ display:flex; gap:28px; flex-wrap:wrap; margin-bottom:40px; }
.footer-links a{ font-size:15px; color:var(--white); border-bottom:1px solid var(--hairline-dark); padding-bottom:2px; }
.footer-links a:hover{ border-color:var(--white); }
.footer-fine{ color:var(--steel-500); font-size:13px; }

@media (max-width:640px){
  .nav-links{ display:none; }
  .def-row{ grid-template-columns:1fr; gap:4px; }
}

/* ============================================================
   Write-up pages
   ============================================================ */
.writeup-hero{ padding:44px 0 40px; }
.back-link{ font-size:14px; color:var(--steel-300); }
.back-link:hover{ color:var(--white); }
.writeup-hero h1{ font-size:clamp(26px, 4.5vw, 36px); color:var(--white); margin:20px 0 12px; max-width:20ch; }
.writeup-hero p.dek{ color:var(--silver-200); font-size:16px; max-width:60ch; }
.writeup-hero .meta-line{ color:var(--steel-300); font-size:14px; margin-top:14px; }

.writeup-body{ padding:56px 0 64px; max-width:700px; }
.writeup-body h2{ font-size:21px; color:var(--navy-800); margin:36px 0 14px; padding-bottom:10px; border-bottom:1px solid var(--hairline); }
.writeup-body h2:first-child{ margin-top:0; }
.writeup-body h3{ font-size:16px; color:var(--ink); margin:22px 0 10px; }
.writeup-body p{ color:var(--ink-soft); margin-bottom:14px; font-size:15.5px; }
.writeup-body ul, .writeup-body ol{ color:var(--ink-soft); margin:0 0 14px 22px; font-size:15.5px; }
.writeup-body li{ margin-bottom:6px; }
.writeup-body li p{ margin-bottom:0; display:inline; }
.writeup-body strong{ color:var(--ink); }
.writeup-body hr{ border:none; border-top:1px solid var(--hairline); margin:32px 0; }
.writeup-body blockquote{ border-left:2px solid var(--steel-500); padding:2px 18px; color:var(--ink-soft); margin:0 0 14px; font-style:italic; }
.writeup-body code{ font-family:ui-monospace, "SF Mono", Menlo, monospace; font-size:13px; background:#EEEEEA; color:var(--navy-800); padding:2px 5px; border-radius:2px; }
.writeup-body pre{ background:var(--navy-950); border-radius:3px; padding:18px 20px; overflow-x:auto; margin-bottom:20px; }
.writeup-body pre code{ background:none; padding:0; color:#DCE3EA; font-size:13px; line-height:1.6; }
.writeup-body img{ max-width:100%; display:block; border:1px solid var(--hairline); margin:6px 0 20px; }
.writeup-footer{ padding:30px 0 60px; border-top:1px solid var(--hairline); }

/* ---------- Archive (all write-ups) ---------- */
.archive-hero{ padding:48px 0 40px; }
.archive-hero h1{ color:var(--white); font-size:clamp(28px,4.5vw,38px); margin:18px 0 10px; }
.archive-hero p{ color:var(--silver-200); max-width:56ch; }