:root {
  --bg: #0f172a;
  --panel: #111827;
  --text: #e5e7eb;
  --muted: #94a3b8;
  --accent: #38bdf8;
  --accent-2: #22c55e;
  --border: rgba(255, 255, 255, 0.08);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: Arial, Helvetica, sans-serif;
  background: linear-gradient(180deg, #0f172a 0%, #111827 100%);
  color: var(--text);
  line-height: 1.5;
}

.container {
  width: min(100% - 2rem, 1000px);
  margin: 0 auto;
}

.site-header {
  padding: 1rem 0;
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  backdrop-filter: blur(8px);
  background: rgba(15, 23, 42, 0.85);
}

.nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
}

.logo {
  font-weight: 700;
  letter-spacing: 0.04em;
}

nav a {
  color: var(--text);
  text-decoration: none;
  margin-left: 1rem;
  font-size: 0.95rem;
}

.hero {
  padding: 5rem 0 3rem;
  text-align: center;
}

.hero h1 {
  font-size: clamp(2rem, 5vw, 4rem);
  margin: 0 0 1rem;
}

.hero p {
  color: var(--muted);
  max-width: 700px;
  margin: 0 auto 2rem;
  font-size: 1.1rem;
}

.buttons {
  display: flex;
  justify-content: center;
  gap: 1rem;
  flex-wrap: wrap;
}

button,
.secondary {
  border: none;
  cursor: pointer;
  padding: 0.9rem 1.2rem;
  border-radius: 12px;
  font-size: 1rem;
  text-decoration: none;
  transition: transform 0.15s ease, opacity 0.15s ease;
}

button:hover,
.secondary:hover {
  transform: translateY(-1px);
  opacity: 0.95;
}

.primary {
  background: var(--accent);
  color: #082f49;
  font-weight: 700;
}

.secondary {
  background: transparent;
  color: var(--text);
  border: 1px solid var(--border);
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1rem;
  padding: 2rem 0 4rem;
}

.card {
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid var(--border);
  border-radius: 18px;
  padding: 1.25rem;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.15);
}

.card h3 {
  margin-top: 0;
}

.muted {
  color: var(--muted);
}

.demo-panel {
  margin: 0 0 4rem;
  padding: 1.5rem;
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid var(--border);
  border-radius: 18px;
  text-align: center;
}

#counter {
  font-size: 2rem;
  margin: 0.5rem 0 1rem;
  color: var(--accent-2);
  font-weight: 700;
}

footer {
  border-top: 1px solid var(--border);
  padding: 1.5rem 0 3rem;
  color: var(--muted);
  text-align: center;
}