:root {
  --bg: #ffffff;
  --bg-alt: #f7f7f5;
  --ink: #0f1115;
  --text: #33363d;
  --text-dim: #6b7280;
  --border: #e7e7e3;
  --border-strong: #d7d7d1;
  --accent: #1f4fd8;
  --accent-ink: #163bab;
  --code-bg: #0f1115;
  --code-text: #e7eaf0;
  --tok-kw: #7aa2f7;
  --tok-str: #9ece6a;
  --tok-com: #636b8a;
  --tok-fn: #e0af68;
  --tok-num: #ff9e64;
  --tok-type: #2ac3de;
  --radius: 8px;
  --maxw: 1120px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  font-size: 17px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3 {
  color: var(--ink);
  line-height: 1.15;
  margin: 0 0 0.5em;
  letter-spacing: -0.02em;
  font-weight: 680;
}
h1 { font-size: clamp(2.05rem, 4.4vw, 2.95rem); letter-spacing: -0.03em; }
h2 { font-size: clamp(1.5rem, 3vw, 2rem); }
h3 { font-size: 1.05rem; letter-spacing: -0.01em; }
p { margin: 0 0 1em; }
a { color: var(--accent); text-decoration: none; }
a:hover { color: var(--accent-ink); }
strong { color: var(--ink); font-weight: 640; }
code {
  font-family: var(--mono);
  font-size: 0.88em;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  padding: 0.08em 0.36em;
  border-radius: 4px;
}

.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }
.mono { font-family: var(--mono); }

.label {
  font-family: var(--mono);
  font-size: 0.8rem;
  color: var(--text-dim);
  margin: 0 0 1.1em;
}
.label::before { content: "# "; color: var(--accent); }

.lead { font-size: 1.12rem; color: var(--text-dim); max-width: 46em; }

/* Nav */
.nav {
  position: sticky;
  top: 0;
  z-index: 20;
  background: var(--bg);
  border-bottom: 1px solid var(--border);
}
.nav-inner {
  display: flex;
  align-items: center;
  gap: 28px;
  height: 60px;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 24px;
}
.wordmark {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--ink);
  letter-spacing: -0.02em;
}
.wordmark:hover { color: var(--ink); }
.logo-mark { height: 26px; width: auto; display: block; }
.nav-links { display: flex; gap: 22px; flex: 1; font-size: 0.95rem; }
.nav-links a { color: var(--text-dim); }
.nav-links a:hover { color: var(--ink); }
.nav-right { display: flex; align-items: center; gap: 16px; }
.nav-right .lic { color: var(--text-dim); font-family: var(--mono); font-size: 0.78rem; }

/* Buttons */
.btn {
  display: inline-block;
  padding: 0.62em 1.2em;
  border-radius: var(--radius);
  font-weight: 560;
  font-size: 0.95rem;
  border: 1px solid transparent;
}
.btn-primary { background: var(--ink); color: #fff; }
.btn-primary:hover { background: #000; color: #fff; }
.btn-ghost { border-color: var(--border-strong); color: var(--ink); }
.btn-ghost:hover { border-color: var(--ink); }
.textlink { font-weight: 560; }
.textlink::after { content: " \2192"; }

/* Sections */
.section { padding: 44px 0; border-top: 1px solid var(--border); }
.section.alt { background: var(--bg-alt); }

/* Hero */
.hero { padding: 60px 0 44px; }
.hero-grid {
  display: grid;
  grid-template-columns: 1.02fr 0.98fr;
  gap: 48px;
  align-items: center;
}
.hero-sub { font-size: 1.16rem; color: var(--text-dim); max-width: 36em; margin-bottom: 1.7em; }
.hero-cta { display: flex; gap: 18px; align-items: center; flex-wrap: wrap; }

/* Code block */
.code {
  background: var(--code-bg);
  color: var(--code-text);
  border-radius: 10px;
  padding: 20px 22px;
  font-family: var(--mono);
  font-size: 0.82rem;
  line-height: 1.7;
  overflow-x: auto;
  border: 1px solid #1c1f27;
}
.code pre { margin: 0; white-space: pre; }
.tok-kw { color: var(--tok-kw); }
.tok-str { color: var(--tok-str); }
.tok-com { color: var(--tok-com); }
.tok-fn { color: var(--tok-fn); }
.tok-num { color: var(--tok-num); }
.tok-type { color: var(--tok-type); }

/* Pillars */
.pillars { display: grid; grid-template-columns: repeat(3, 1fr); gap: 40px; margin-top: 2.6em; }
.pillar { border-top: 2px solid var(--ink); padding-top: 18px; }
.pillar h3 { margin-bottom: 0.5em; }
.pillar p { color: var(--text-dim); font-size: 0.97rem; margin-bottom: 0.9em; }
.pillar .knobs { font-family: var(--mono); font-size: 0.78rem; color: var(--text-dim); }
.pillar .knobs span { color: var(--accent); }
.boundary { margin-top: 2.8em; font-size: 1.05rem; color: var(--ink); max-width: 46em; }
.footnote { margin-top: 1.1em; font-size: 0.95rem; color: var(--text-dim); max-width: 46em; }

/* Demo */
.frame {
  border: 1px solid var(--border-strong);
  border-radius: 10px;
  overflow: hidden;
  background: var(--code-bg);
  margin: 1.8em 0 0.9em;
  box-shadow: 0 1px 2px rgba(15, 17, 21, 0.05);
}
.frame img { display: block; width: 100%; height: auto; }
figure { margin: 0; }
figcaption { font-family: var(--mono); font-size: 0.8rem; color: var(--text-dim); }

/* Architecture */
.arch-img {
  border: 1px solid var(--border);
  border-radius: 10px;
  overflow: hidden;
  background: #fff;
  margin: 1.9em 0;
}
.arch-img img { display: block; width: 100%; height: auto; }
.notes {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
  margin-top: 1.6em;
  border-top: 1px solid var(--border);
  padding-top: 1.6em;
}
.note h3 { font-size: 0.95rem; }
.note p { margin: 0; color: var(--text-dim); font-size: 0.95rem; }

/* Who */
.who { display: grid; grid-template-columns: repeat(3, 1fr); gap: 32px; margin-top: 2.2em; }
.who div { border-top: 2px solid var(--ink); padding-top: 18px; }
.who p { margin: 0; color: var(--text); font-size: 0.97rem; }

/* Watch (videos) */
.watch { display: grid; grid-template-columns: repeat(2, 1fr); gap: 32px; margin-top: 2em; }
.video-embed {
  display: block; width: 100%; padding: 0; margin: 0;
  border: 1px solid var(--border-strong); border-radius: 10px; overflow: hidden;
  position: relative; aspect-ratio: 16 / 9; background: #000; cursor: pointer;
}
.video-embed img { width: 100%; height: 100%; object-fit: cover; display: block; opacity: 0.92; }
.video-embed:hover img { opacity: 1; }
.video-embed .play {
  position: absolute; top: 50%; left: 50%; transform: translate(-50%, -50%);
  width: 62px; height: 62px; border-radius: 999px;
  background: rgba(15, 17, 21, 0.72); border: 1px solid rgba(255, 255, 255, 0.28);
}
.video-embed .play::after {
  content: ""; position: absolute; top: 50%; left: 55%; transform: translate(-50%, -50%);
  border-style: solid; border-width: 10px 0 10px 17px;
  border-color: transparent transparent transparent #fff;
}
.video-embed:hover .play { background: rgba(31, 79, 216, 0.85); }
.video iframe, .hero-video iframe {
  width: 100%; aspect-ratio: 16 / 9; display: block;
  border: 1px solid var(--border-strong); border-radius: 10px;
}
.video h3 { margin: 0.9em 0 0.2em; font-size: 1.05rem; }
.video .dur { font-family: var(--mono); font-size: 0.78rem; color: var(--text-dim); font-weight: 400; margin-left: 0.5em; }
.video p { color: var(--text-dim); font-size: 0.95rem; margin: 0; }
.hero-video .video-embed { box-shadow: 0 2px 12px rgba(15, 17, 21, 0.09); }
.hero-vid-cap { font-family: var(--mono); font-size: 0.78rem; color: var(--text-dim); margin: 0.7em 0 0; text-align: center; }

/* Closing (dark band) */
.closing { background: var(--ink); border-top: none; }
.closing h2 { color: #fff; }
.closing .lead { color: #b7bcc7; }
.closing .label { color: #8b93a7; }
.closing .label::before { color: #6b7280; }
.closing .btn-primary { background: #fff; color: var(--ink); }
.closing .btn-primary:hover { background: #f0f0f0; }
.closing .btn-ghost { border-color: #3a3d47; color: #e7eaf0; }
.closing .btn-ghost:hover { border-color: #fff; }

/* Footer */
.footer { border-top: 1px solid var(--border); padding: 30px 0; }
.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 14px;
  color: var(--text-dim);
  font-size: 0.88rem;
}
.footer .mark { font-family: var(--mono); color: var(--ink); }
.footer-links { display: flex; gap: 18px; }
.footer-links a { color: var(--text-dim); }
.footer-links a:hover { color: var(--ink); }

@media (max-width: 900px) {
  .nav-links { display: none; }
  .hero-grid { grid-template-columns: 1fr; gap: 34px; }
  .pillars, .who, .notes, .watch { grid-template-columns: 1fr; gap: 28px; }
}