:root {
  --bg-0: #070b12;
  --bg-1: #0d1420;
  --bg-2: #121b2b;
  --text: #d8e2f1;
  --muted: #95a7bf;
  --line: #2a3950;
  --accent: #3dd9b1;
  --accent-2: #49a7ff;
  --panel: rgba(14, 22, 34, 0.82);
  --radius: 16px;
  --shadow: 0 20px 60px rgba(0, 0, 0, 0.45);
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  min-height: 100%;
}

body {
  font-family: "Space Grotesk", "Segoe UI", sans-serif;
  color: var(--text);
  background:
    radial-gradient(1000px 500px at 10% -10%, #17325b 0%, transparent 60%),
    radial-gradient(900px 600px at 95% 5%, #1f2748 0%, transparent 60%),
    linear-gradient(160deg, var(--bg-0), var(--bg-1) 50%, var(--bg-2));
  display: flex;
  justify-content: center;
  padding: 36px 18px 72px;
}

.bg-grid {
  position: fixed;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(to right, rgba(85, 130, 190, 0.09) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(85, 130, 190, 0.09) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(circle at center, black 35%, transparent 85%);
}

.bg-glow {
  position: fixed;
  pointer-events: none;
  border-radius: 999px;
  filter: blur(70px);
  opacity: 0.3;
}

.bg-glow-a {
  width: 360px;
  height: 360px;
  left: -80px;
  top: 120px;
  background: #2dd4bf;
}

.bg-glow-b {
  width: 320px;
  height: 320px;
  right: -60px;
  bottom: 120px;
  background: #3b82f6;
}

.shell {
  width: min(980px, 100%);
  position: relative;
  z-index: 1;
  display: grid;
  gap: 22px;
  animation: fade-up 500ms ease-out;
}

.hero,
.panel {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  backdrop-filter: blur(6px);
}

.hero {
  padding: clamp(22px, 4vw, 40px);
}

.eyebrow {
  font-family: "JetBrains Mono", "Consolas", monospace;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: var(--accent);
  margin: 0 0 10px;
  font-size: 0.8rem;
}

h1 {
  margin: 0;
  line-height: 1.05;
  font-size: clamp(2rem, 6vw, 3.4rem);
  max-width: 14ch;
}

.lede {
  color: var(--muted);
  max-width: 62ch;
  line-height: 1.7;
  margin: 18px 0 26px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.btn {
  text-decoration: none;
  padding: 11px 16px;
  border-radius: 11px;
  border: 1px solid transparent;
  font-weight: 700;
  transition: transform 180ms ease, border-color 180ms ease, background-color 180ms ease;
}

.btn:hover {
  transform: translateY(-2px);
}

.btn-primary {
  background: linear-gradient(120deg, var(--accent), var(--accent-2));
  color: #001018;
}

.btn-ghost {
  color: var(--text);
  border-color: var(--line);
  background: rgba(15, 24, 36, 0.7);
}

.panel {
  padding: 22px;
}

h2 {
  margin-top: 0;
  font-size: 1.2rem;
}

h3 {
  margin: 0 0 8px;
  font-size: 1rem;
}

p {
  margin: 0;
}

ul {
  margin: 0;
  padding-left: 20px;
  color: var(--muted);
  line-height: 1.8;
}

ol {
  margin: 0 0 14px;
  padding-left: 20px;
  color: var(--muted);
  line-height: 1.8;
}

.docs-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.docs-nav a {
  text-decoration: none;
  color: var(--text);
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 9px 12px;
  background: rgba(13, 20, 32, 0.75);
  transition: border-color 180ms ease, transform 180ms ease;
}

.docs-nav a:hover {
  border-color: var(--accent-2);
  transform: translateY(-2px);
}

.doc-section {
  display: grid;
  gap: 14px;
}

.section-copy {
  color: var(--muted);
  line-height: 1.7;
}

.concept-grid,
.control-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.concept-grid article,
.control-grid article {
  border: 1px solid var(--line);
  border-radius: 12px;
  background: rgba(9, 15, 24, 0.72);
  padding: 14px;
}

.concept-grid p,
.control-grid p {
  color: var(--muted);
  line-height: 1.55;
}

pre {
  margin: 0;
  border-radius: 12px;
  border: 1px solid #2b3f58;
  background: #08101b;
  overflow-x: auto;
}

code {
  font-family: "JetBrains Mono", "Consolas", monospace;
  font-size: 0.88rem;
  color: #c7d8ea;
}

pre code {
  display: block;
  padding: 16px;
  line-height: 1.55;
}

.hljs {
  background: #08101b;
  color: #c7d8ea;
  padding: 16px;
  border-radius: 12px;
}

.footer {
  color: var(--muted);
  text-align: center;
  padding: 6px 0 2px;
}

@keyframes fade-up {
  from {
    opacity: 0;
    transform: translateY(8px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ── sample grid ───────────────────────────────────────── */

.sample-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
}

.sample-card {
  display: flex;
  flex-direction: column;
  gap: 6px;
  text-decoration: none;
  color: var(--text);
  border: 1px solid var(--line);
  border-radius: 12px;
  background: rgba(9, 15, 24, 0.72);
  padding: 16px;
  transition: border-color 180ms ease, transform 180ms ease;
}

.sample-card:hover {
  border-color: var(--accent-2);
  transform: translateY(-2px);
}

.sample-card h3 {
  margin: 0;
  font-size: 1rem;
}

.sample-card p {
  color: var(--muted);
  line-height: 1.55;
  font-size: 0.9rem;
  flex: 1;
}

.sample-card-link {
  font-family: "JetBrains Mono", monospace;
  font-size: 0.78rem;
  color: var(--accent);
}

/* ── preview tabs ─────────────────────────────────────── */

.preview-tabs {
  display: flex;
  gap: 0;
  border-bottom: 1px solid var(--line);
  margin-bottom: 0;
}

.preview-tab {
  padding: 8px 16px;
  font-family: "JetBrains Mono", monospace;
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--muted);
  background: transparent;
  border: none;
  border-bottom: 2px solid transparent;
  cursor: pointer;
  transition: color 150ms ease, border-color 150ms ease;
}

.preview-tab:hover {
  color: var(--text);
}

.preview-tab.active {
  color: var(--accent);
  border-bottom-color: var(--accent);
}

.preview-tab-content {
  display: none;
}

.preview-tab-content.active {
  display: block;
}

.preview-terminal {
  background: #0a0e17;
  border-radius: 0 0 12px 12px;
  padding: 8px;
  min-height: 340px;
}

.preview-terminal .xterm {
  height: 100%;
}

.preview-source {
  margin: 0;
}

.preview-source pre {
  margin: 0;
  border-radius: 0 0 12px 12px;
}

/* ── breadcrumb ───────────────────────────────────────── */

.breadcrumb {
  font-size: 0.88rem;
  color: var(--muted);
}

.breadcrumb a {
  color: var(--accent);
  text-decoration: none;
}

.breadcrumb a:hover {
  text-decoration: underline;
}

@media (max-width: 640px) {
  body {
    padding-top: 18px;
  }

  .panel,
  .hero {
    padding: 18px;
  }

  .concept-grid,
  .control-grid {
    grid-template-columns: 1fr;
  }

  .sample-grid {
    grid-template-columns: 1fr;
  }
}

@media (min-width: 641px) and (max-width: 900px) {
  .sample-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}