:root {
  --bg: #05070b;
  --panel: rgba(12, 18, 28, 0.78);
  --panel-strong: rgba(18, 27, 43, 0.92);
  --text: #eef7ff;
  --muted: #9fb4c8;
  --cyan: #23e7ff;
  --red: #ff2b4f;
  --lime: #b8ff42;
  --purple: #a855f7;
  --line: rgba(35, 231, 255, 0.18);
  --shadow: 0 30px 90px rgba(0, 0, 0, 0.42);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: var(--text);
  background: radial-gradient(circle at top left, rgba(35, 231, 255, 0.14), transparent 34%),
              radial-gradient(circle at 80% 10%, rgba(255, 43, 79, 0.18), transparent 30%),
              var(--bg);
  min-height: 100vh;
  overflow-x: hidden;
}

a { color: inherit; text-decoration: none; }

.grid-bg {
  position: fixed;
  inset: 0;
  pointer-events: none;
  opacity: 0.28;
  background-image: linear-gradient(var(--line) 1px, transparent 1px), linear-gradient(90deg, var(--line) 1px, transparent 1px);
  background-size: 52px 52px;
  mask-image: linear-gradient(to bottom, black, transparent 85%);
}

.nav {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  padding: 1rem clamp(1rem, 4vw, 4rem);
  backdrop-filter: blur(18px);
  background: rgba(5, 7, 11, 0.72);
  border-bottom: 1px solid var(--line);
}

.brand, .nav nav { display: flex; align-items: center; gap: 0.9rem; }
.brand { font-weight: 800; letter-spacing: 0.08em; }
.brand-mark {
  display: grid;
  place-items: center;
  width: 2.4rem;
  height: 2.4rem;
  border: 1px solid var(--cyan);
  border-radius: 0.8rem;
  color: var(--cyan);
  box-shadow: 0 0 24px rgba(35, 231, 255, 0.22);
}
.nav nav a { color: var(--muted); font-size: 0.9rem; }
.nav nav a:hover { color: var(--cyan); }

.section { padding: clamp(4rem, 9vw, 8rem) clamp(1rem, 6vw, 6rem); position: relative; }
.hero { min-height: 82vh; display: grid; grid-template-columns: minmax(0, 1.1fr) minmax(320px, 0.9fr); align-items: center; gap: 4rem; }
.eyebrow { color: var(--lime); text-transform: uppercase; letter-spacing: 0.18em; font-size: 0.78rem; font-weight: 800; }
h1, h2, h3, p { margin-top: 0; }
h1 { font-size: clamp(3rem, 8vw, 7.5rem); line-height: 0.9; letter-spacing: -0.08em; margin-bottom: 1.5rem; }
h2 { font-size: clamp(2rem, 5vw, 4.5rem); line-height: 0.95; letter-spacing: -0.06em; margin-bottom: 1rem; }
h3 { font-size: 1.3rem; }
.lede, .split p, .card p, .boundary li, .timeline li { color: var(--muted); font-size: 1.04rem; line-height: 1.7; }
.lede { max-width: 720px; font-size: clamp(1.1rem, 2vw, 1.32rem); }
.hero-actions { display: flex; gap: 1rem; flex-wrap: wrap; margin-top: 2rem; }
.button { padding: 0.95rem 1.2rem; border-radius: 999px; border: 1px solid var(--line); font-weight: 800; }
.primary { background: linear-gradient(135deg, var(--cyan), var(--red)); color: #061017; border: 0; }
.ghost { background: rgba(255,255,255,0.04); }

.orbital-card {
  position: relative;
  min-height: 440px;
  border: 1px solid var(--line);
  background: linear-gradient(145deg, rgba(12,18,28,0.92), rgba(5,7,11,0.58));
  border-radius: 2rem;
  box-shadow: var(--shadow);
  overflow: hidden;
}
.orbital-card::before, .orbital-card::after {
  content: "";
  position: absolute;
  inset: 12%;
  border: 1px dashed rgba(35,231,255,0.22);
  border-radius: 50%;
  animation: spin 16s linear infinite;
}
.orbital-card::after { inset: 25%; animation-duration: 10s; animation-direction: reverse; border-color: rgba(255,43,79,0.26); }
.core {
  position: absolute;
  inset: 50% auto auto 50%;
  transform: translate(-50%, -50%);
  width: 150px;
  height: 150px;
  border-radius: 50%;
  display: grid;
  place-items: center;
  font-weight: 900;
  background: radial-gradient(circle, rgba(35,231,255,0.32), rgba(255,43,79,0.12));
  border: 1px solid var(--cyan);
  box-shadow: 0 0 70px rgba(35,231,255,0.2);
}
.orbit {
  position: absolute;
  padding: 0.65rem 0.8rem;
  border-radius: 999px;
  background: var(--panel-strong);
  border: 1px solid var(--line);
  color: var(--text);
  font-size: 0.82rem;
}
.o1 { top: 18%; left: 16%; }
.o2 { top: 20%; right: 12%; }
.o3 { bottom: 18%; left: 18%; }
.o4 { bottom: 20%; right: 14%; }

.split { display: grid; grid-template-columns: 0.9fr 1.1fr; gap: 2rem; align-items: center; }
.terminal { border: 1px solid var(--line); border-radius: 1.4rem; background: #070b11; box-shadow: var(--shadow); overflow: hidden; }
.terminal-bar { display: flex; gap: 0.45rem; padding: 1rem; border-bottom: 1px solid var(--line); }
.terminal-bar span { width: 0.8rem; height: 0.8rem; border-radius: 50%; background: var(--red); }
.terminal-bar span:nth-child(2) { background: var(--lime); }
.terminal-bar span:nth-child(3) { background: var(--cyan); }
pre { margin: 0; padding: 2rem; min-height: 240px; white-space: pre-wrap; color: var(--cyan); line-height: 1.65; }
.section-head { max-width: 860px; margin-bottom: 2rem; }
.cards { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 1rem; }
.card, .boundary {
  border: 1px solid var(--line);
  background: var(--panel);
  border-radius: 1.4rem;
  padding: 1.4rem;
  box-shadow: 0 18px 60px rgba(0,0,0,0.18);
}
.card { transition: transform 180ms ease, border-color 180ms ease; }
.card:hover { transform: translateY(-6px); border-color: rgba(35,231,255,0.62); }
.boundary-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 1rem; }
.timeline { display: grid; gap: 1rem; padding-left: 1.2rem; }
.footer { padding: 2rem clamp(1rem, 6vw, 6rem); color: var(--muted); border-top: 1px solid var(--line); }
.reveal { opacity: 0; transform: translateY(18px); transition: opacity 700ms ease, transform 700ms ease; }
.reveal.visible { opacity: 1; transform: translateY(0); }

@keyframes spin { to { transform: rotate(360deg); } }

@media (max-width: 900px) {
  .hero, .split, .boundary-grid { grid-template-columns: 1fr; }
  .cards { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .nav { align-items: flex-start; flex-direction: column; }
}

@media (max-width: 900px) {
  .nav { align-items: stretch; gap: 0.5rem; }
  .nav nav { flex-wrap: wrap; justify-content: flex-start; }
  .nav nav a { padding: 0.5rem 0.25rem; min-height: 2.75rem; }
}

@media (max-width: 560px) {
  .cards { grid-template-columns: 1fr; }
  .nav { padding-top: 0.75rem; }
  .brand { min-height: 2.75rem; }
  .nav nav { width: 100%; }
  .nav nav a { flex: 1 1 auto; text-align: left; min-height: 2.75rem; }
  .orbital-card { min-height: 360px; }
}

/* ============ B1 production hardening ============ */

/* Keyboard focus visibility */
a:focus-visible,
button:focus-visible,
select:focus-visible,
input:focus-visible,
textarea:focus-visible {
  outline: 3px solid var(--cyan);
  outline-offset: 3px;
  border-radius: 4px;
}

/* Skip link: hidden until focused */
.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  z-index: 100;
  padding: 0.9rem 1.2rem;
  background: var(--panel-strong);
  color: var(--text);
  border: 1px solid var(--cyan);
  border-radius: 0 0 0.9rem 0;
  font-weight: 800;
}
.skip-link:focus {
  left: 0;
}

/* 3D city labels (created by app.js) */
.city-label-layer {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 5;
}
.city-label {
  position: absolute;
  left: 0;
  top: 0;
  color: var(--text);
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  text-shadow: 0 1px 8px rgba(0, 0, 0, 0.9), 0 0 12px rgba(35, 231, 255, 0.35);
  white-space: nowrap;
  transition: opacity 160ms ease;
  will-change: transform;
}

/* Static fallback when WebGL is unavailable */
.no-webgl #city3d {
  display: none;
}
.city-fallback {
  border: 1px solid var(--line);
  border-radius: 1.4rem;
  background: var(--panel);
  padding: 1.6rem;
  box-shadow: var(--shadow);
  max-width: 520px;
}
.city-fallback .city-fallback-heading {
  color: var(--cyan);
  font-weight: 800;
  letter-spacing: 0.06em;
}
.city-fallback p {
  color: var(--muted);
  font-size: 0.95rem;
  line-height: 1.6;
}
.city-fallback ul {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  padding: 0;
  margin: 1rem 0 0;
  list-style: none;
}
.city-fallback li {
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 0.45rem 0.85rem;
  color: var(--text);
  font-size: 0.85rem;
}

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
  .orbital-card::before, .orbital-card::after { animation: none; }
  .card { transition: none; }
  * { animation-duration: 0.001ms !important; animation-iteration-count: 1 !important; transition-duration: 0.001ms !important; }
}