/* =========================================================
   Ian Birch — personal site
   Single lightweight stylesheet. No frameworks, no jQuery.
   Light/dark via prefers-color-scheme. Static-friendly.
   ========================================================= */

/* ---------- Reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
* { margin: 0; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body { -webkit-font-smoothing: antialiased; text-rendering: optimizeLegibility; }
img, svg { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
ul { list-style: none; padding: 0; }
button { font: inherit; cursor: pointer; }

/* ---------- Theme tokens ---------- */
:root {
  --font: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --maxw: 1080px;
  --radius: 14px;
  --radius-sm: 9px;
  --gap: clamp(1rem, 2.5vw, 1.5rem);
  --pad-section: clamp(3rem, 8vw, 6rem);

  /* Light palette (default) */
  --bg: #f7f8fb;
  --bg-elev: #ffffff;
  --bg-soft: #eef1f7;
  --text: #14161c;
  --text-soft: #4a505c;
  --text-mut: #6b7280;
  --border: #e4e8f0;
  --accent: #4f46e5;
  --accent-2: #0ea5e9;
  --accent-ink: #ffffff;
  --shadow: 0 1px 2px rgba(16,24,40,.06), 0 8px 24px rgba(16,24,40,.06);
  --shadow-lg: 0 12px 40px rgba(16,24,40,.12);
  --chip-bg: #eef0fe;
  --chip-text: #3730a3;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0b0d12;
    --bg-elev: #12151d;
    --bg-soft: #171b25;
    --text: #eef1f7;
    --text-soft: #b9c0cf;
    --text-mut: #8a92a4;
    --border: #232836;
    --accent: #7c8cff;
    --accent-2: #38bdf8;
    --accent-ink: #0b0d12;
    --shadow: 0 1px 2px rgba(0,0,0,.4), 0 10px 30px rgba(0,0,0,.35);
    --shadow-lg: 0 16px 50px rgba(0,0,0,.5);
    --chip-bg: #1b2030;
    --chip-text: #aab4ff;
  }
}

/* ---------- Base ---------- */
body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  font-size: 17px;
}
.container { width: 100%; max-width: var(--maxw); margin-inline: auto; padding-inline: clamp(1.1rem, 4vw, 2rem); }

h1, h2, h3, h4 { line-height: 1.15; font-weight: 700; letter-spacing: -0.02em; }
p { color: var(--text-soft); }
strong { color: var(--text); font-weight: 650; }

.accent-text { color: var(--accent); }
.eyebrow {
  display: inline-block; font-size: 1.05rem; font-weight: 700; letter-spacing: .14em;
  text-transform: uppercase; color: var(--accent); margin-bottom: .8rem;
}

/* Accessibility: skip link */
.skip { position: absolute; left: -999px; top: 0; background: var(--accent); color: var(--accent-ink); padding: .6rem 1rem; border-radius: 0 0 var(--radius-sm) 0; z-index: 200; }
.skip:focus { left: 0; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; border-radius: 4px; }

/* ---------- Header / Nav ---------- */
.site-header {
  position: sticky; top: 0; z-index: 100;
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: saturate(180%) blur(12px);
  -webkit-backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--border);
}
.nav { display: flex; align-items: center; justify-content: space-between; height: 64px; }
.brand { font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace; font-weight: 700; letter-spacing: -0.01em; font-size: 1rem; }
.brand .dot { color: var(--accent); }
.nav-links { display: flex; align-items: center; gap: clamp(1rem, 2.4vw, 2rem); }
.nav-links a { color: var(--text-soft); font-size: .95rem; font-weight: 550; transition: color .18s; }
.nav-links a:hover { color: var(--text); }
.nav-cta {
  background: var(--accent); color: var(--accent-ink) !important;
  padding: .5rem .95rem; border-radius: 999px; font-weight: 650 !important;
  box-shadow: var(--shadow);
}
.nav-cta:hover { filter: brightness(1.06); }
.nav-toggle { display: none; background: none; border: 0; padding: .3rem; color: var(--text); }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; gap: .5rem;
  padding: .72rem 1.25rem; border-radius: 999px; font-weight: 650; font-size: .96rem;
  border: 1px solid transparent; transition: transform .12s ease, filter .18s, background .18s, border-color .18s;
}
.btn:hover { transform: translateY(-1px); }
.btn-primary { background: var(--accent); color: var(--accent-ink); box-shadow: var(--shadow); }
.btn-primary:hover { filter: brightness(1.07); }
.btn-ghost { background: var(--bg-elev); color: var(--text); border-color: var(--border); box-shadow: var(--shadow); }
.btn-ghost:hover { border-color: var(--accent); color: var(--accent); }
.btn svg { width: 18px; height: 18px; }

/* ---------- Hero ---------- */
.hero { padding-top: clamp(3rem, 7vw, 5.5rem); padding-bottom: var(--pad-section); }
.hero-grid { display: grid; grid-template-columns: .7fr 1.85fr; gap: clamp(2rem, 5vw, 4rem); align-items: center; }
.hero-copy { order: 2; }
.hero h1 { font-size: clamp(2.4rem, 6vw, 4rem); letter-spacing: -0.04em; }
.hero .role { font-size: clamp(1.05rem, 2.4vw, 1.4rem); font-weight: 650; color: var(--text); margin-top: .5rem; }
.hero .role .sep { color: var(--text-mut); font-weight: 400; }
.hero .pitch { font-size: clamp(1.02rem, 1.6vw, 1.15rem); margin-top: 1.15rem; max-width: 50ch; text-align: center; }
.hero .pitch .attr { display: block; margin-top: .45rem; color: var(--text-mut); font-size: .9em; }
.hero .meta-row { display: flex; flex-wrap: wrap; gap: 1.1rem; margin-top: 1.35rem; color: var(--text-mut); font-size: .92rem; }
.hero .meta-row span { display: inline-flex; align-items: center; gap: .45rem; }
.hero .meta-row svg { width: 16px; height: 16px; color: var(--accent); }
.hero-cta { display: flex; flex-wrap: wrap; gap: .8rem; margin-top: 1.9rem; }

.portrait-wrap { justify-self: center; position: relative; order: 1; }
.portrait {
  width: min(160px, 40vw); aspect-ratio: 1; border-radius: 50%; object-fit: cover;
  border: 4px solid var(--bg-elev); box-shadow: var(--shadow);
}
.portrait-wrap::before {
  content: ""; position: absolute; inset: 0; margin: auto; width: 82%; height: 82%;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  filter: blur(38px); opacity: .16; z-index: -1; border-radius: 50%;
}

/* ---------- Sections ---------- */
section { scroll-margin-top: 84px; }
.section { padding-block: var(--pad-section); border-top: 1px solid var(--border); }
.section-head { margin-bottom: clamp(2rem, 4vw, 3rem); }
.section-head p { margin-top: .8rem; font-size: 1.05rem; }

/* ---------- About ---------- */
.about-grid { display: grid; grid-template-columns: 1.4fr 1fr; gap: clamp(2rem, 5vw, 3.5rem); align-items: start; }
.about-copy p + p { margin-top: 1rem; }
.facts { display: grid; gap: .9rem; }
.fact {
  background: var(--bg-elev); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 1.1rem 1.25rem; box-shadow: var(--shadow);
}
.fact .num { font-size: 1.5rem; font-weight: 800; color: var(--accent); letter-spacing: -0.02em; }
.fact .lbl { color: var(--text-mut); font-size: .92rem; margin-top: .15rem; }

/* ---------- Highlights cards ---------- */
.cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--gap); }
.card {
  background: var(--bg-elev); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 1.5rem; box-shadow: var(--shadow); transition: transform .16s, border-color .18s, box-shadow .18s;
}
.card:hover { transform: translateY(-3px); border-color: color-mix(in srgb, var(--accent) 45%, var(--border)); box-shadow: var(--shadow-lg); }
.card .ic {
  width: 44px; height: 44px; border-radius: 12px; display: grid; place-items: center;
  background: var(--chip-bg); color: var(--accent); margin-bottom: 1rem;
}
.card .ic svg { width: 22px; height: 22px; }
.card h3 { font-size: 1.12rem; }
.card p { margin-top: .5rem; font-size: .97rem; }

/* ---------- Case study callout ---------- */
.callout {
  position: relative; overflow: hidden; border-radius: var(--radius);
  background: linear-gradient(135deg, color-mix(in srgb, var(--accent) 14%, var(--bg-elev)), var(--bg-elev));
  border: 1px solid color-mix(in srgb, var(--accent) 30%, var(--border));
  box-shadow: var(--shadow); padding: clamp(1.6rem, 4vw, 2.5rem);
}
.callout .eyebrow { color: var(--accent-2); }
.callout h3 { font-size: clamp(1.3rem, 3vw, 1.7rem); }
.callout p { margin-top: .9rem; }
.callout .tags { display: flex; flex-wrap: wrap; gap: .5rem; margin-top: 1.2rem; }
.work-stack { display: grid; gap: var(--gap); }

/* ---------- Experience timeline ---------- */
.timeline { position: relative; display: grid; gap: 1.1rem; }
.timeline::before {
  content: ""; position: absolute; left: 11px; top: 8px; bottom: 8px; width: 2px;
  background: linear-gradient(var(--accent), transparent); opacity: .35;
}
.job {
  position: relative; padding-left: 2.6rem;
}
.job::before {
  content: ""; position: absolute; left: 4px; top: 6px; width: 16px; height: 16px; border-radius: 50%;
  background: var(--bg); border: 3px solid var(--accent); box-shadow: 0 0 0 4px color-mix(in srgb, var(--accent) 16%, transparent);
}
.job-card {
  background: var(--bg-elev); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 1.3rem 1.4rem; box-shadow: var(--shadow); transition: border-color .18s, box-shadow .18s;
}
.job-card:hover { border-color: color-mix(in srgb, var(--accent) 40%, var(--border)); box-shadow: var(--shadow-lg); }
.job-top { display: flex; flex-wrap: wrap; justify-content: space-between; gap: .3rem 1rem; align-items: baseline; }
.job-title { font-size: 1.15rem; }
.job-co { color: var(--accent); font-weight: 650; }
.job-date { color: var(--text-mut); font-size: .88rem; font-weight: 550; white-space: nowrap; }
.job-bullets { margin-top: .85rem; display: grid; gap: .5rem; }
.job-bullets li { position: relative; padding-left: 1.25rem; color: var(--text-soft); font-size: .98rem; }
.job-bullets li::before { content: ""; position: absolute; left: 0; top: .62em; width: 6px; height: 6px; border-radius: 50%; background: var(--accent); }

/* Collapsible earlier roles */
.earlier { margin-top: 1.3rem; padding-left: 2.6rem; }
.earlier > summary {
  cursor: pointer; list-style: none; display: inline-flex; align-items: center; gap: .5rem;
  color: var(--accent); font-weight: 650; font-size: .96rem; padding: .5rem 0;
}
.earlier > summary::-webkit-details-marker { display: none; }
.earlier > summary .chev { transition: transform .2s; }
.earlier[open] > summary .chev { transform: rotate(90deg); }
.earlier .timeline { margin-top: 1rem; }

/* ---------- Skills ---------- */
.skill-groups { display: grid; grid-template-columns: repeat(2, 1fr); gap: var(--gap); }
.skill-group {
  background: var(--bg-elev); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 1.4rem 1.5rem; box-shadow: var(--shadow);
}
.skill-group h3 { font-size: 1.02rem; color: var(--text); margin-bottom: .95rem; display: flex; align-items: center; gap: .55rem; }
.skill-group h3 .dot { width: 9px; height: 9px; border-radius: 50%; background: var(--accent); }
.chips { display: flex; flex-wrap: wrap; gap: .5rem; }
.chip {
  background: var(--chip-bg); color: var(--chip-text); font-size: .85rem; font-weight: 600;
  padding: .38rem .7rem; border-radius: 999px; border: 1px solid transparent;
}

/* ---------- Contact ---------- */
.contact { text-align: center; }
.contact .section-head { margin-inline: auto; }
.contact h2 { font-size: clamp(1.9rem, 4.5vw, 2.8rem); }

/* Contact form */
.contact-form { max-width: 620px; margin: 0 auto; text-align: left; display: grid; gap: 1rem; }
.contact-form .form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; }
.contact-form .field { display: grid; gap: .4rem; }
.contact-form label { font-size: .88rem; font-weight: 600; color: var(--text-soft); }
.contact-form input, .contact-form textarea {
  width: 100%; font: inherit; color: var(--text); background: var(--bg-elev);
  border: 1px solid var(--border); border-radius: var(--radius-sm); padding: .72rem .85rem;
  transition: border-color .18s, box-shadow .18s;
}
.contact-form input:focus, .contact-form textarea:focus {
  outline: none; border-color: var(--accent);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--accent) 18%, transparent);
}
.contact-form textarea { resize: vertical; min-height: 130px; }
.contact-form button { justify-self: start; border: 0; margin-top: .1rem; }
.contact-form .g-recaptcha { margin-top: .1rem; }
.form-status { min-height: 1.2em; font-size: .92rem; margin: 0; }
.form-status.ok { color: #16a34a; }
.form-status.err { color: #dc2626; }
@media (max-width: 560px) { .contact-form .form-row { grid-template-columns: 1fr; } }

/* ---------- Footer ---------- */
.site-footer { border-top: 1px solid var(--border); padding-block: 2.2rem; }
.footer-in { display: flex; flex-wrap: wrap; gap: 1rem; justify-content: space-between; align-items: center; color: var(--text-mut); font-size: .9rem; }
.socials { display: flex; gap: .6rem; }
.socials a {
  width: 38px; height: 38px; border-radius: 50%; display: grid; place-items: center;
  background: var(--bg-elev); border: 1px solid var(--border); color: var(--text-soft); transition: color .18s, border-color .18s, transform .12s;
}
.socials a:hover { color: var(--accent); border-color: var(--accent); transform: translateY(-2px); }
.socials svg { width: 18px; height: 18px; }

/* ---------- Reveal on scroll (progressive enhancement) ---------- */
/* Only hide when JS is available, so no-JS visitors & crawlers see everything. */
html.js .reveal { opacity: 0; transform: translateY(16px); transition: opacity .6s ease, transform .6s ease; }
html.js .reveal.in { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  html.js .reveal { opacity: 1; transform: none; transition: none; }
}

/* ---------- Responsive ---------- */
@media (max-width: 860px) {
  .hero-grid { grid-template-columns: 1fr; }
  .portrait-wrap { order: -1; justify-self: start; }
  .about-grid { grid-template-columns: 1fr; }
  .cards { grid-template-columns: 1fr; }
  .skill-groups { grid-template-columns: 1fr; }
}
@media (max-width: 680px) {
  body { font-size: 16px; }
  .nav-links { position: fixed; inset: 64px 0 auto 0; flex-direction: column; align-items: stretch;
    gap: 0; background: var(--bg-elev); border-bottom: 1px solid var(--border);
    padding: .6rem 1.1rem 1.1rem; transform: translateY(-140%); transition: transform .28s ease; box-shadow: var(--shadow-lg); }
  .nav-links.open { transform: none; }
  .nav-links a { display: block; padding: .8rem .2rem; border-bottom: 1px solid var(--border); }
  .nav-links .nav-cta { display: block; text-align: center; margin-top: .8rem; padding: .7rem 1rem; border-bottom: 0; }
  .nav-toggle { display: inline-flex; }
}

/* ---------- Print ---------- */
@media print {
  .site-header, .hero-cta, .nav-toggle, .callout, .socials, .contact-form, .site-footer { display: none !important; }
  body { font-size: 11pt; background: #fff; color: #000; }
  .section { border: 0; padding-block: 1rem; }
  .job-card, .skill-group, .fact { box-shadow: none; border-color: #ccc; }
}