/* A.R.C Studio — landing page
 * Palette + type lifted from the product UI:
 *  - background: near-black warm-neutral
 *  - primary:  amber (neural activation heat)
 *  - mono:     JetBrains Mono for technical labels
 *  - sans:     Inter for everything else
 */

:root {
  --bg: #0a0a0a;
  --bg-elev-1: #121110;
  --bg-elev-2: #1a1816;
  --fg: #f4f1ea;
  --fg-muted: #a39e94;
  --fg-dim: #6f6a61;
  --border: #2a2724;
  --border-strong: #3a3530;
  --primary: #f0a657;          /* amber */
  --primary-strong: #ffb56b;
  --primary-soft: rgba(240, 166, 87, 0.12);
  --primary-line: rgba(240, 166, 87, 0.35);
  --shadow: 0 1px 0 rgba(255, 255, 255, 0.03) inset;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  line-height: 1.55;
}

a { color: var(--fg); text-decoration: none; }
a:hover { color: var(--primary); }

code, .mono {
  font-family: 'JetBrains Mono', ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 0.86em;
}

code {
  background: var(--bg-elev-2);
  border: 1px solid var(--border);
  padding: 0.15em 0.45em;
  border-radius: 3px;
  color: var(--fg);
  word-break: break-all;
}

.container {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* ── topbar ─────────────────────────────────────────── */
.topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(10, 10, 10, 0.85);
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(8px);
}
.topbar-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 56px;
}
.brand {
  display: flex; align-items: center; gap: 0.55rem;
  font-weight: 600; letter-spacing: -0.01em;
}
.brand-mark { color: var(--primary); font-size: 1.1rem; }
.brand-name { font-size: 0.95rem; }
.nav { display: flex; align-items: center; gap: 1.5rem; }
.nav a {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--fg-muted);
}
.nav a:hover { color: var(--fg); }
.nav-cta {
  border: 1px solid var(--border-strong);
  padding: 0.4rem 0.7rem;
  border-radius: 3px;
  color: var(--fg) !important;
}
.nav-cta:hover { border-color: var(--primary-line); color: var(--primary) !important; }
@media (max-width: 640px) { .nav a:not(.nav-cta) { display: none; } }

/* ── hero ────────────────────────────────────────────── */
.hero {
  padding: 7rem 1.5rem 5rem;
  max-width: 880px;
}
.eyebrow {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.72rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--primary);
  margin: 0 0 1rem;
}
.hero h1 {
  font-size: clamp(2.6rem, 6vw, 4.4rem);
  line-height: 1.02;
  letter-spacing: -0.03em;
  margin: 0 0 1.1rem;
  font-weight: 600;
}
.hero .tagline {
  font-size: clamp(1.15rem, 2vw, 1.5rem);
  color: var(--fg);
  margin: 0 0 0.6rem;
  font-weight: 500;
  letter-spacing: -0.005em;
}
.hero .lede {
  font-size: 1.05rem;
  color: var(--fg-muted);
  max-width: 56ch;
  margin: 0 0 2.4rem;
}
.cta-row {
  display: flex; gap: 0.75rem; flex-wrap: wrap;
  margin-bottom: 3rem;
}
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  padding: 0.75rem 1.25rem;
  font-size: 0.88rem;
  font-weight: 500;
  border-radius: 3px;
  border: 1px solid transparent;
  transition: background-color 120ms ease, color 120ms ease, border-color 120ms ease;
  cursor: pointer;
}
.btn-primary {
  background: var(--primary);
  color: #1a1208;
  border-color: var(--primary);
}
.btn-primary:hover {
  background: var(--primary-strong);
  color: #1a1208;
  border-color: var(--primary-strong);
}
.btn-secondary {
  background: transparent;
  color: var(--fg);
  border-color: var(--border-strong);
}
.btn-secondary:hover {
  border-color: var(--primary-line);
  color: var(--primary);
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1rem;
  border-top: 1px solid var(--border);
  padding-top: 1.6rem;
  margin: 0;
}
.hero-stats > div { display: flex; flex-direction: column; gap: 0.25rem; }
.hero-stats dt {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.66rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--fg-dim);
}
.hero-stats dd {
  margin: 0;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.92rem;
  color: var(--fg);
}
@media (max-width: 640px) {
  .hero-stats { grid-template-columns: 1fr; gap: 0.6rem; }
}

/* ── section heads ───────────────────────────────────── */
section { padding: 4.5rem 1.5rem; }
.section-head {
  display: flex; align-items: baseline; gap: 0.9rem;
  margin-bottom: 2.2rem;
  padding-bottom: 0.85rem;
  border-bottom: 1px solid var(--border);
}
.section-tag {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.66rem;
  letter-spacing: 0.16em;
  color: var(--primary);
}
.section-head h2 {
  margin: 0;
  font-size: 1.5rem;
  font-weight: 500;
  letter-spacing: -0.01em;
}

/* ── demo ────────────────────────────────────────────── */
.video-frame {
  border: 1px solid var(--border);
  background: var(--bg-elev-1);
  aspect-ratio: 16 / 9;
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}
.video-frame iframe,
.video-frame video {
  width: 100%; height: 100%; border: 0; display: block;
}
.video-placeholder {
  text-align: center;
  padding: 2rem;
  color: var(--fg-dim);
}
.placeholder-title {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.78rem;
  letter-spacing: 0.1em;
  color: var(--primary);
  margin: 0 0 0.6rem;
  text-transform: uppercase;
}
.placeholder-sub {
  font-size: 0.85rem;
  margin: 0;
  max-width: 38ch;
  margin-inline: auto;
}
.caption {
  margin-top: 0.85rem;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.72rem;
  letter-spacing: 0.06em;
  color: var(--fg-muted);
  text-align: center;
}

/* ── three-column ────────────────────────────────────── */
.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1rem;
}
@media (max-width: 880px) { .grid-3 { grid-template-columns: 1fr; } }
.card {
  border: 1px solid var(--border);
  background: var(--bg-elev-1);
  padding: 1.6rem 1.4rem;
  display: flex;
  flex-direction: column;
  gap: 0.7rem;
}
.card-num {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.72rem;
  letter-spacing: 0.16em;
  color: var(--primary);
  margin: 0;
}
.card h3 {
  margin: 0;
  font-size: 1.05rem;
  font-weight: 500;
  letter-spacing: -0.005em;
}
.card p {
  margin: 0;
  color: var(--fg-muted);
  font-size: 0.92rem;
  line-height: 1.6;
}

/* ── stack list ──────────────────────────────────────── */
.stack-list {
  list-style: none;
  margin: 0;
  padding: 0;
  border: 1px solid var(--border);
  background: var(--bg-elev-1);
}
.stack-list li {
  display: grid;
  grid-template-columns: 200px 1fr;
  gap: 1rem;
  padding: 0.95rem 1.25rem;
  border-bottom: 1px solid var(--border);
}
.stack-list li:last-child { border-bottom: 0; }
.stack-list .k {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.7rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--fg-dim);
  align-self: center;
}
.stack-list .v {
  font-size: 0.95rem;
  color: var(--fg);
}
@media (max-width: 640px) {
  .stack-list li { grid-template-columns: 1fr; gap: 0.25rem; }
}
.amd-tagline {
  margin: 1.6rem 0 0;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.86rem;
  color: var(--primary);
  letter-spacing: 0.04em;
}

/* ── steps ───────────────────────────────────────────── */
.steps {
  list-style: none;
  margin: 0 0 1.8rem;
  padding: 0;
  display: flex; flex-direction: column; gap: 0.6rem;
}
.steps li {
  display: flex;
  gap: 1.2rem;
  padding: 1.1rem 1.25rem;
  border: 1px solid var(--border);
  background: var(--bg-elev-1);
}
.step-n {
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.85rem;
  color: var(--primary);
  min-width: 1.5rem;
  letter-spacing: 0.04em;
}
.steps h4 { margin: 0 0 0.3rem; font-size: 0.98rem; font-weight: 500; }
.steps p {
  margin: 0;
  color: var(--fg-muted);
  font-size: 0.9rem;
  word-break: break-word;
}

/* ── footer ──────────────────────────────────────────── */
.footer {
  border-top: 1px solid var(--border);
  margin-top: 3rem;
  padding: 1.8rem 0 2.4rem;
}
.footer-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}
.foot-line {
  margin: 0;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.74rem;
  color: var(--fg-muted);
  letter-spacing: 0.04em;
}
.foot-links {
  margin: 0;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.74rem;
  letter-spacing: 0.04em;
}
.foot-links a { color: var(--fg-muted); }
.foot-links a:hover { color: var(--primary); }

.privacy-note {
  margin: 1.4rem auto 0;
  font-family: 'JetBrains Mono', monospace;
  font-size: 0.66rem;
  letter-spacing: 0.06em;
  color: var(--fg-dim);
  text-align: center;
}