:root {
  --bg: #05070d;
  --bg-soft: #0b101c;
  --panel: rgba(18, 26, 44, 0.72);
  --border: rgba(90, 160, 255, 0.18);
  --text: #e6edf7;
  --muted: #8ea0bd;
  --accent: #4d7cff;
  --accent-2: #22d3ee;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: "Segoe UI", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  overflow-x: hidden;
  position: relative;
  min-height: 100vh;
}

.grid-bg {
  position: fixed;
  inset: 0;
  z-index: -1;
  background:
    radial-gradient(circle at 15% 10%, rgba(77, 124, 255, 0.22), transparent 45%),
    radial-gradient(circle at 85% 0%, rgba(34, 211, 238, 0.16), transparent 40%),
    linear-gradient(rgba(90, 160, 255, 0.05) 1px, transparent 1px) 0 0 / 44px 44px,
    linear-gradient(90deg, rgba(90, 160, 255, 0.05) 1px, transparent 1px) 0 0 / 44px 44px,
    var(--bg);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 22px clamp(20px, 6vw, 72px);
  max-width: 1200px;
  margin: 0 auto;
}

.logo {
  font-size: 1.35rem;
  font-weight: 800;
  letter-spacing: 2px;
}

.logo span {
  color: var(--accent-2);
}

.nav nav {
  display: flex;
  gap: 28px;
}

.nav a {
  color: var(--muted);
  text-decoration: none;
  font-size: 0.95rem;
  transition: color 0.25s;
}

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

.hero {
  max-width: 1200px;
  margin: 0 auto;
  padding: clamp(56px, 12vh, 140px) clamp(20px, 6vw, 72px) clamp(48px, 8vh, 90px);
  text-align: center;
}

.eyebrow {
  color: var(--accent-2);
  font-family: "SFMono-Regular", Consolas, monospace;
  letter-spacing: 1px;
  font-size: 0.85rem;
  margin-bottom: 20px;
}

.hero h1 {
  font-size: clamp(2.4rem, 6.5vw, 4.5rem);
  line-height: 1.1;
  font-weight: 800;
  letter-spacing: -1px;
}

.grad {
  background: linear-gradient(100deg, var(--accent), var(--accent-2));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.sub {
  max-width: 620px;
  margin: 26px auto 0;
  color: var(--muted);
  font-size: clamp(1rem, 2vw, 1.15rem);
}

.actions {
  margin-top: 40px;
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  padding: 13px 30px;
  border-radius: 10px;
  text-decoration: none;
  font-weight: 600;
  font-size: 0.98rem;
  transition: transform 0.2s, box-shadow 0.3s, background 0.3s;
}

.btn.primary {
  background: linear-gradient(100deg, var(--accent), var(--accent-2));
  color: #04101f;
  box-shadow: 0 10px 30px rgba(77, 124, 255, 0.35);
}

.btn.primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 14px 40px rgba(77, 124, 255, 0.5);
}

.btn.ghost {
  border: 1px solid var(--border);
  color: var(--text);
  background: rgba(255, 255, 255, 0.02);
}

.btn.ghost:hover {
  background: rgba(90, 160, 255, 0.08);
  transform: translateY(-2px);
}

.features {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 clamp(20px, 6vw, 72px) clamp(64px, 10vh, 120px);
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 24px;
}

.card {
  position: relative;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 34px 28px;
  backdrop-filter: blur(12px);
  transition: transform 0.3s, border-color 0.3s, box-shadow 0.3s;
  overflow: hidden;
}

.card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--accent-2), transparent);
  opacity: 0;
  transition: opacity 0.3s;
}

.card:hover {
  transform: translateY(-6px);
  border-color: rgba(34, 211, 238, 0.45);
  box-shadow: 0 20px 45px rgba(0, 0, 0, 0.45);
}

.card:hover::before {
  opacity: 1;
}

.icon {
  width: 52px;
  height: 52px;
  display: grid;
  place-items: center;
  font-size: 1.5rem;
  border-radius: 12px;
  background: rgba(77, 124, 255, 0.12);
  border: 1px solid var(--border);
  margin-bottom: 22px;
}

.card h3 {
  font-size: 1.2rem;
  margin-bottom: 10px;
}

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

.footer {
  text-align: center;
  padding: 28px 20px 40px;
  color: var(--muted);
  font-size: 0.85rem;
  border-top: 1px solid var(--border);
}

@media (max-width: 640px) {
  .nav nav {
    gap: 18px;
  }
}