:root {
  --bg: #0f0f11;
  --surface: #18181b;
  --text: #f4f4f5;
  --muted: #a1a1aa;
  --border: #27272a;
  --accent: #2dd4bf;
  --accent-soft: #10302c;
  --radius: 16px;
  color-scheme: dark;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 17px/1.65 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration-color: var(--accent); text-underline-offset: 3px; }
a:hover { color: var(--accent); }
svg { width: 18px; height: 18px; flex: none; }
.sprite { position: absolute; }
.wrap { max-width: 1080px; margin: 0 auto; padding: 0 24px; }

/* Top bar */
.topbar { position: sticky; top: 0; z-index: 10; background: color-mix(in srgb, var(--bg) 88%, transparent); backdrop-filter: blur(10px); }
.nav { display: flex; align-items: center; justify-content: space-between; height: 68px; }
.brand { display: inline-flex; align-items: center; gap: 10px; font-weight: 700; text-decoration: none; }
.mark {
  display: grid; place-items: center; width: 30px; height: 30px; border-radius: 9px;
  background: var(--text); color: var(--bg); font-size: 12px; font-weight: 800; letter-spacing: .02em;
}
.nav ul { display: flex; gap: 28px; list-style: none; margin: 0; padding: 0; }
.nav ul a { color: var(--muted); text-decoration: none; font-size: 15px; font-weight: 500; }
.nav ul a:hover { color: var(--text); }

/* Shared type */
.eyebrow, .label {
  margin: 0 0 12px; color: var(--accent);
  font-size: 12px; font-weight: 700; letter-spacing: .14em; text-transform: uppercase;
}
h1, h2, h3 { margin: 0; letter-spacing: -.025em; }
h2 { font-size: clamp(1.7rem, 3.4vw, 2.4rem); line-height: 1.15; font-weight: 800; margin-bottom: 40px; max-width: 28ch; }
h3 { font-size: 1.25rem; line-height: 1.3; font-weight: 750; }

/* Hero */
.hero { padding: 88px 24px 112px; display: grid; grid-template-columns: 1fr 340px; gap: 64px; align-items: center; }
.portrait {
  width: 100%; height: auto; aspect-ratio: 4 / 5; object-fit: cover; display: block;
  border-radius: 24px; border: 1px solid var(--border);
  box-shadow: 0 30px 60px -20px rgba(0, 0, 0, .6), 0 0 0 6px var(--accent-soft);
}
h1 { font-size: clamp(2.6rem, 6.6vw, 5rem); line-height: 1.02; font-weight: 850; max-width: 15ch; margin-bottom: 28px; }
.lead { color: var(--muted); font-size: 1.15rem; max-width: 60ch; margin: 0 0 32px; }
.links { display: flex; flex-wrap: wrap; gap: 10px; list-style: none; margin: 0; padding: 0; }
.pill {
  display: inline-flex; align-items: center; gap: 8px; padding: 9px 16px; border-radius: 999px;
  background: var(--surface); border: 1px solid var(--border); text-decoration: none; font-size: 15px; font-weight: 600;
  transition: border-color .2s, transform .2s;
}
.pill:hover { border-color: var(--text); color: var(--text); transform: translateY(-1px); }

/* Sections */
.section { padding: 96px 24px; border-top: 1px solid var(--border); }

.principles { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }
.principle {
  display: flex; flex-direction: column; gap: 12px;
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 24px;
}
.principle .label { margin: 0; }
.principle > p:not(.label) { margin: 0; color: var(--muted); font-size: 15px; }
.reads { list-style: none; margin: auto 0 0; padding: 14px 0 0; border-top: 1px solid var(--border); display: grid; gap: 6px; }
.reads a { font-size: 14px; font-weight: 600; text-decoration: none; }
.reads a::after { content: " ↗"; color: var(--accent); }

.feature {
  display: grid; grid-template-columns: 96px 1fr; gap: 32px; align-items: start;
  padding: 40px 0; border-bottom: 1px solid var(--border);
}
.feature:first-of-type { padding-top: 0; }
.feature:last-of-type { border-bottom: 0; padding-bottom: 0; }
.feature-mark { display: grid; place-items: center; width: 96px; height: 96px; border-radius: 24px; }
.feature-mark svg { width: 48px; height: 48px; }
.mark-ha { background: #0c2a3d; color: #7dd3fc; }
.mark-write { background: #33240a; color: #fcd34d; }
.mark-code { background: var(--accent-soft); color: var(--accent); }
.feature-body h3 { font-size: clamp(1.5rem, 2.6vw, 2rem); font-weight: 800; margin-bottom: 12px; }
.feature-body > p:not(.label) { color: var(--muted); max-width: 62ch; margin: 0 0 20px; }
.btn {
  display: inline-flex; align-items: center; gap: 8px; padding: 10px 18px; border-radius: 999px;
  border: 1.5px solid var(--text); text-decoration: none; font-size: 15px; font-weight: 600;
  transition: background .2s, color .2s;
}
.btn svg { width: 16px; height: 16px; }
.btn:hover { background: var(--text); color: var(--bg); }

.lab {
  display: grid; grid-template-columns: 1.2fr 1fr; gap: 40px; align-items: start;
  background: linear-gradient(160deg, var(--accent-soft), var(--surface) 60%);
  border: 1px solid var(--border); border-radius: 24px; padding: 40px;
}
.lab h3 { font-size: clamp(1.6rem, 3vw, 2.2rem); font-weight: 800; margin-bottom: 14px; }
.lab-body > p { color: var(--muted); margin: 0 0 24px; }
.lab-actions { display: flex; flex-wrap: wrap; gap: 10px; margin-bottom: 16px; }
.btn-solid { background: var(--accent); border-color: var(--accent); color: var(--bg); }
.btn-solid:hover { background: var(--text); border-color: var(--text); }
.lab .note { font-size: 13px; margin: 0; }
.suites { list-style: none; margin: 0; padding: 0; display: grid; gap: 8px; }
.suites li { position: relative; }
.suite {
  display: flex; flex-direction: column; align-items: flex-start; width: 100%; text-align: left;
  padding: 12px 44px 12px 40px; position: relative; cursor: help;
  font: inherit; color: inherit; background: var(--bg);
  border: 1px solid var(--border); border-radius: 12px;
  transition: border-color .15s ease, background-color .15s ease;
}
.suite::before {
  content: "✓"; position: absolute; left: 14px; top: 12px;
  color: var(--accent); font-weight: 800;
}
/* Small "i" badge that signals there is more to read. */
.suite::after {
  content: "i"; position: absolute; right: 14px; top: 50%; transform: translateY(-50%);
  width: 18px; height: 18px; border-radius: 50%; border: 1px solid var(--border);
  display: grid; place-items: center; color: var(--muted);
  font: italic 700 11px/1 Georgia, serif;
  transition: color .15s ease, border-color .15s ease;
}
.suite:hover, .suite:focus-visible, .suite[aria-expanded="true"] { border-color: var(--accent); }
.suite:hover::after, .suite:focus-visible::after, .suite[aria-expanded="true"]::after { color: var(--accent); border-color: var(--accent); }
.suite:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.suite span { font-weight: 650; font-size: 15px; }
.suite small { color: var(--muted); font-size: 13px; font-family: ui-monospace, SFMono-Regular, Menlo, monospace; }

.tip {
  position: absolute; z-index: 10; left: 0; right: 0; bottom: calc(100% + 10px);
  padding: 12px 14px; border-radius: 10px;
  background: var(--surface); border: 1px solid var(--border); border-left: 3px solid var(--accent);
  box-shadow: 0 12px 32px rgb(0 0 0 / .45);
  color: var(--text); font-size: 14px; line-height: 1.5;
  opacity: 0; visibility: hidden; transform: translateY(4px); pointer-events: none;
  transition: opacity .15s ease, transform .15s ease, visibility 0s linear .15s;
}
.tip::after {
  content: ""; position: absolute; left: 40px; top: 100%;
  border: 7px solid transparent; border-top-color: var(--border);
}
.suites li:hover .tip,
.suite:focus-visible + .tip,
.suite[aria-expanded="true"] + .tip {
  opacity: 1; visibility: visible; transform: none;
  transition: opacity .15s ease, transform .15s ease;
}
.suites li.tip-dismissed .tip { opacity: 0; visibility: hidden; }
@media (prefers-reduced-motion: reduce) {
  .suite, .suite::after, .tip { transition: none; }
}

.toolbox { margin: 0; display: grid; grid-template-columns: repeat(auto-fit, minmax(190px, 1fr)); gap: 16px; }
.toolbox div { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 20px; }
.toolbox dt { font-weight: 750; margin-bottom: 6px; }
.toolbox dd { margin: 0; color: var(--muted); font-size: 15px; }

/* Footer */
.footer { border-top: 1px solid var(--border); padding: 32px 0; color: var(--muted); font-size: 14px; }
.footer-row { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 12px; }
.footer p { margin: 0; }
.icons { display: flex; gap: 16px; list-style: none; margin: 0; padding: 0; }
.icons a { color: var(--muted); display: inline-flex; }
.icons a:hover { color: var(--text); }
.icons svg { width: 20px; height: 20px; }

@media (max-width: 960px) {
  .principles { grid-template-columns: 1fr 1fr; }
  .hero { grid-template-columns: 1fr 240px; gap: 40px; }
  .lab { grid-template-columns: 1fr; }
}
@media (max-width: 640px) {
  .wrap { padding: 0 16px; }
  .nav ul { display: none; }
  .hero { padding: 48px 16px 72px; }
  .hero { display: flex; flex-direction: column-reverse; align-items: flex-start; gap: 28px; }
  .portrait { width: 120px; border-radius: 50%; aspect-ratio: 1; object-position: 50% 15%; box-shadow: 0 0 0 4px var(--accent-soft); }
  .section { padding: 64px 16px; }
  h2 { margin-bottom: 28px; }
  .principles { grid-template-columns: 1fr; }
  .feature { grid-template-columns: 1fr; gap: 20px; }
  .lab { grid-template-columns: 1fr; padding: 24px; gap: 28px; }
  .feature-mark { width: 72px; height: 72px; border-radius: 18px; }
  .feature-mark svg { width: 36px; height: 36px; }
}