:root {
  --bg: #f7f8fc;
  --surface: #ffffff;
  --text: #1b1f2e;
  --muted: #6b7280;
  --primary: #4361ee;
  --primary-hover: #3651d4;
  --border: #e5e7eb;
}

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

body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, "PingFang SC", "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
}

.wrap {
  max-width: 920px;
  margin: 0 auto;
  padding: 0 1.25rem;
}

.header {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 10;
}

.header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 56px;
}

.logo {
  font-weight: 700;
  font-size: 1.125rem;
  color: var(--text);
  text-decoration: none;
}

.nav {
  display: flex;
  gap: 1.25rem;
  flex-wrap: wrap;
}

.nav a {
  color: var(--muted);
  text-decoration: none;
  font-size: 0.9375rem;
}

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

.hero {
  padding: 3.5rem 1.25rem 4rem;
  text-align: center;
}

.hero h1 {
  margin: 0 0 1rem;
  font-size: clamp(1.75rem, 5vw, 2.5rem);
  letter-spacing: -0.02em;
  line-height: 1.2;
}

.hero__lead {
  max-width: 36rem;
  margin: 0 auto 1.75rem;
  color: var(--muted);
  font-size: 1.0625rem;
}

.hero__cta {
  display: flex;
  gap: 0.75rem;
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.65rem 1.25rem;
  border-radius: 10px;
  font-weight: 600;
  font-size: 0.9375rem;
  text-decoration: none;
  border: none;
  cursor: pointer;
}

.btn--primary {
  background: var(--primary);
  color: #fff;
}

.btn--primary:hover { background: var(--primary-hover); }

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

.features {
  padding: 3rem 1.25rem 4rem;
}

.features h2 {
  text-align: center;
  margin: 0 0 2rem;
  font-size: 1.5rem;
}

.feature-grid {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 1.25rem;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
}

.feature-grid li {
  background: var(--surface);
  padding: 1.5rem;
  border-radius: 12px;
  border: 1px solid var(--border);
}

.feature-grid h3 {
  margin: 0 0 0.5rem;
  font-size: 1.0625rem;
}

.feature-grid p {
  margin: 0;
  color: var(--muted);
  font-size: 0.9375rem;
}

.download {
  padding: 2rem 1.25rem 4rem;
  text-align: center;
}

.download h2 { margin-top: 0; }

.download__note { margin-top: 1.25rem; }

.footer {
  border-top: 1px solid var(--border);
  padding: 1.25rem;
  background: var(--surface);
  font-size: 0.875rem;
  color: var(--muted);
}

.footer__inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.footer a {
  color: var(--primary);
  text-decoration: none;
}