:root {
  --bg: #0e161f;
  --bg-grid: radial-gradient(circle at 18% 12%, rgba(124, 169, 209, 0.10), transparent 45%),
    radial-gradient(circle at 82% 78%, rgba(45, 212, 196, 0.08), transparent 50%);
  --panel: #141f2b;
  --panel-strong: #1b2836;
  --text: #e4eaf0;
  --muted: #7c8ca0;
  --border: #263444;
  --primary: #7ca9d1;
  --primary-dark: #b9d3e8;
  --teal: #2dd4c4;
  --shadow: 0 1px 2px rgba(0, 0, 0, 0.4), 0 6px 20px rgba(0, 0, 0, 0.28);
}

:root[data-theme="dark"] {
  --bg: #0e161f;
  --panel: #141f2b;
  --panel-strong: #1b2836;
  --text: #e4eaf0;
  --muted: #7c8ca0;
  --border: #263444;
  --primary: #7ca9d1;
  --primary-dark: #b9d3e8;
  --teal: #2dd4c4;
}

:root[data-theme="light"] {
  --bg: #f8fafc;
  --panel: #ffffff;
  --panel-strong: #eef2f6;
  --text: #334155;
  --muted: #64748b;
  --border: #dce3ea;
  --primary: #1f4e79;
  --primary-dark: #2f6394;
  --teal: #14b8a6;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background-color: var(--bg);
  background-image: var(--bg-grid);
  color: var(--text);
  font-family: "IBM Plex Sans", "Inter", "Segoe UI", -apple-system, BlinkMacSystemFont, sans-serif;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

.skip-link {
  position: absolute;
  left: -999px;
  top: 0;
  background: var(--panel-strong);
  color: var(--text);
  padding: 0.75rem 1rem;
  z-index: 100;
  border-radius: 0 0 6px 0;
}
.skip-link:focus { left: 0; }

a { color: inherit; }

/* Top bar */
.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.25rem clamp(1.25rem, 4vw, 3rem);
  max-width: 1280px;
  margin: 0 auto;
}

.brand-lockup {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  text-decoration: none;
}
.brand-mark { width: 30px; height: 30px; color: var(--primary); flex-shrink: 0; }
.wordmark {
  font-family: "IBM Plex Sans", sans-serif;
  font-weight: 600;
  font-size: 1.15rem;
  letter-spacing: 0.01em;
}

.login-button {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.55rem 1.1rem;
  border: 1px solid var(--border);
  border-radius: 6px;
  text-decoration: none;
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.85rem;
  color: var(--text);
  background: var(--panel);
  transition: border-color 0.15s ease, color 0.15s ease;
}
.login-button:hover,
.login-button:focus-visible {
  border-color: var(--primary);
  color: var(--primary-dark);
  outline: none;
}
.login-button span { transition: transform 0.15s ease; }
.login-button:hover span { transform: translateX(2px); }

/* Hero */
.hero {
  max-width: 1280px;
  margin: 0 auto;
  padding: clamp(2rem, 6vw, 5rem) clamp(1.25rem, 4vw, 3rem) clamp(3rem, 8vw, 6rem);
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(280px, 0.95fr);
  gap: clamp(2rem, 5vw, 4rem);
  align-items: center;
}

.eyebrow {
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.78rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--teal);
  margin: 0 0 0.85rem;
}

.hero h1 {
  font-size: clamp(2.1rem, 4.2vw, 3.4rem);
  line-height: 1.12;
  margin: 0 0 1rem;
  text-wrap: balance;
  font-weight: 700;
}

.hero-tagline {
  font-family: "IBM Plex Mono", monospace;
  font-size: 1rem;
  color: var(--primary-dark);
  margin: 0 0 1.25rem;
}

.hero-sub {
  font-size: 1.05rem;
  line-height: 1.65;
  color: var(--muted);
  max-width: 46ch;
  margin: 0 0 2rem;
}

.hero-actions { display: flex; gap: 1rem; flex-wrap: wrap; align-items: center; }

.cta-primary {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: var(--primary);
  color: var(--bg);
  font-weight: 600;
  padding: 0.85rem 1.5rem;
  border-radius: 7px;
  text-decoration: none;
  transition: filter 0.15s ease;
}
.cta-primary:hover, .cta-primary:focus-visible { filter: brightness(1.08); outline: none; }
.cta-primary span { transition: transform 0.15s ease; }
.cta-primary:hover span { transform: translateX(3px); }

.cta-secondary {
  color: var(--muted);
  text-decoration: none;
  font-size: 0.95rem;
  border-bottom: 1px solid var(--border);
  padding-bottom: 2px;
}
.cta-secondary:hover, .cta-secondary:focus-visible { color: var(--text); border-color: var(--primary); outline: none; }

/* Hero visual — ambient relationship graph */
.hero-visual {
  aspect-ratio: 1;
  display: flex;
  align-items: center;
  justify-content: center;
}
.graph { width: 100%; height: 100%; max-width: 480px; }
.graph-node {
  animation: pulse 3.6s ease-in-out infinite;
  transform-origin: center;
  transform-box: fill-box;
}
@keyframes pulse {
  0%, 100% { opacity: 0.55; transform: scale(1); }
  50% { opacity: 1; transform: scale(1.28); }
}
@media (prefers-reduced-motion: reduce) {
  .graph-node { animation: none; opacity: 0.85; }
}

/* Capabilities */
.capabilities {
  max-width: 1280px;
  margin: 0 auto;
  padding: clamp(2rem, 5vw, 3.5rem) clamp(1.25rem, 4vw, 3rem);
  border-top: 1px solid var(--border);
}
.capabilities h2 {
  font-size: clamp(1.4rem, 2.4vw, 1.9rem);
  margin: 0 0 2rem;
  text-wrap: balance;
}
.capability-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1.25rem;
}
.capability-card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1.5rem;
  box-shadow: var(--shadow);
}
.capability-label {
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--teal);
  margin: 0 0 0.6rem;
}
.capability-card h3 {
  margin: 0 0 0.6rem;
  font-size: 1.1rem;
}
.capability-card p:not(.capability-label) {
  margin: 0;
  color: var(--muted);
  font-size: 0.92rem;
  line-height: 1.55;
}

/* How it thinks */
.how-it-thinks {
  border-top: 1px solid var(--border);
  background: var(--panel-strong);
}
.how-it-thinks-inner {
  max-width: 760px;
  margin: 0 auto;
  padding: clamp(3rem, 7vw, 5rem) clamp(1.25rem, 4vw, 3rem);
  text-align: center;
}
.how-it-thinks h2 {
  font-size: clamp(1.5rem, 3vw, 2.1rem);
  text-wrap: balance;
  margin: 0 0 1.25rem;
}
.how-it-thinks p:not(.eyebrow) {
  color: var(--muted);
  font-size: 1.02rem;
  line-height: 1.7;
  margin: 0;
}
.how-it-thinks .eyebrow { text-align: center; }

/* Footer */
.site-footer {
  max-width: 1280px;
  margin: 0 auto;
  padding: 1.75rem clamp(1.25rem, 4vw, 3rem) 2.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  color: var(--muted);
  font-size: 0.85rem;
  font-family: "IBM Plex Mono", monospace;
}
.site-footer a { text-decoration: none; color: var(--muted); }
.site-footer a:hover, .site-footer a:focus-visible { color: var(--primary-dark); outline: none; }

@media (max-width: 860px) {
  .hero { grid-template-columns: 1fr; }
  .hero-visual { order: -1; max-width: 320px; margin: 0 auto; }
  .hero-sub { max-width: none; }
}