:root {
  --bg: #0f1117;
  --surface: #1a1d27;
  --border: #2a2f3d;
  --text: #e8eaef;
  --muted: #9aa3b5;
  --accent: #6ee7b7;
  --accent-dim: #34d399;
  --radius: 12px;
  --font: "Noto Sans SC", system-ui, sans-serif;
  --mono: "JetBrains Mono", monospace;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  min-height: 100vh;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 50% at 50% -20%, rgba(110, 231, 183, 0.12), transparent),
    radial-gradient(ellipse 60% 40% at 100% 50%, rgba(99, 102, 241, 0.08), transparent);
  pointer-events: none;
  z-index: -1;
}

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

a:hover {
  color: var(--accent-dim);
}

code {
  font-family: var(--mono);
  font-size: 0.9em;
  background: var(--surface);
  padding: 0.15em 0.45em;
  border-radius: 6px;
  border: 1px solid var(--border);
}

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(12px);
  background: rgba(15, 17, 23, 0.85);
  border-bottom: 1px solid var(--border);
}

.nav {
  max-width: 960px;
  margin: 0 auto;
  padding: 1rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--text);
}

.nav-links {
  display: flex;
  gap: 1.75rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-links a {
  color: var(--muted);
  font-size: 0.95rem;
  transition: color 0.2s;
}

.nav-links a:hover {
  color: var(--text);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
}

/* Main */
main {
  max-width: 960px;
  margin: 0 auto;
  padding: 0 1.5rem 4rem;
}

.hero {
  padding: 5rem 0 4rem;
}

.hero-label {
  font-family: var(--mono);
  font-size: 0.85rem;
  color: var(--accent);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin: 0 0 1rem;
}

.hero h1 {
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 700;
  line-height: 1.2;
  margin: 0 0 1.25rem;
}

.highlight {
  background: linear-gradient(135deg, var(--accent), #818cf8);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-desc {
  font-size: 1.125rem;
  color: var(--muted);
  max-width: 36rem;
  margin: 0 0 2rem;
}

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

.btn {
  display: inline-block;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius);
  font-weight: 500;
  font-size: 0.95rem;
  transition: transform 0.15s, box-shadow 0.15s;
}

.btn:hover {
  transform: translateY(-1px);
}

.btn-primary {
  background: var(--accent);
  color: var(--bg);
}

.btn-primary:hover {
  box-shadow: 0 8px 24px rgba(110, 231, 183, 0.25);
  color: var(--bg);
}

.btn-outline {
  border: 1px solid var(--border);
  color: var(--text);
}

.btn-outline:hover {
  border-color: var(--muted);
  color: var(--text);
}

/* Sections */
.section {
  padding: 3rem 0;
  border-top: 1px solid var(--border);
}

.section h2 {
  font-size: 1.5rem;
  margin: 0 0 1.25rem;
}

.section > p {
  color: var(--muted);
  max-width: 40rem;
  margin: 0;
}

/* Cards */
.cards {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 1.25rem;
  margin-top: 0.5rem;
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  transition: border-color 0.2s, transform 0.2s;
}

.card:hover {
  border-color: rgba(110, 231, 183, 0.35);
  transform: translateY(-2px);
}

.card h3 {
  margin: 0 0 0.5rem;
  font-size: 1.1rem;
}

.card p {
  color: var(--muted);
  font-size: 0.95rem;
  margin: 0 0 1rem;
}

.card-link {
  font-size: 0.9rem;
  font-weight: 500;
}

/* Footer */
.site-footer {
  max-width: 960px;
  margin: 0 auto;
  padding: 2rem 1.5rem;
  border-top: 1px solid var(--border);
  text-align: center;
}

.site-footer p {
  margin: 0;
  font-size: 0.875rem;
  color: var(--muted);
}

/* Mobile */
@media (max-width: 640px) {
  .nav-toggle {
    display: flex;
  }

  .nav-links {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    gap: 0;
    background: var(--surface);
    border-bottom: 1px solid var(--border);
    padding: 0.5rem 0;
    display: none;
  }

  .nav-links.open {
    display: flex;
  }

  .nav-links li a {
    display: block;
    padding: 0.75rem 1.5rem;
  }

  .hero {
    padding-top: 3rem;
  }
}