:root {
  --board-top: #46497a;
  --board-bot: #22243c;
  --ink: #1e2030;
  --muted: #5b5e72;
  --card: #ffffff;
  --accent: #4d76e8;
  --accent-2: #6ca2ff;
  --radius: 18px;
  --maxw: 960px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  color: var(--ink);
  background: #f5f6fa;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

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

/* --- Hero --- */
.hero {
  text-align: center;
  padding: 80px 24px 64px;
  color: #fff;
  background: linear-gradient(160deg, var(--board-top), var(--board-bot));
}

.hero__icon {
  width: 160px;
  height: 160px;
  border-radius: 36px;
  box-shadow: 0 18px 50px rgba(0, 0, 0, 0.35);
}

.hero__title {
  margin: 24px 0 8px;
  font-size: 3rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.hero__tagline {
  max-width: 540px;
  margin: 0 auto 32px;
  font-size: 1.15rem;
  color: rgba(255, 255, 255, 0.82);
}

.hero__req {
  margin: 18px 0 0;
  font-size: 0.9rem;
  color: rgba(255, 255, 255, 0.7);
}

.hero__note {
  max-width: 520px;
  margin: 14px auto 0;
  font-size: 0.82rem;
  color: rgba(255, 255, 255, 0.6);
}

.hero__note p { margin: 6px 0; }

.cmd {
  display: block;
  margin: 10px auto;
  padding: 10px 14px;
  max-width: 100%;
  overflow-x: auto;
  background: rgba(0, 0, 0, 0.28);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 8px;
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 0.82rem;
  color: #eaeaf0;
  white-space: nowrap;
  -webkit-user-select: all;
  user-select: all;
}

/* --- Download button --- */
.button {
  display: inline-flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
  padding: 16px 40px;
  border-radius: 14px;
  background: linear-gradient(180deg, var(--accent-2), var(--accent));
  color: #fff;
  font-size: 1.15rem;
  font-weight: 600;
  text-decoration: none;
  box-shadow: 0 10px 26px rgba(77, 118, 232, 0.45);
  transition: transform 0.12s ease, box-shadow 0.12s ease;
}

.button:hover { transform: translateY(-2px); box-shadow: 0 14px 32px rgba(77, 118, 232, 0.55); }
.button:active { transform: translateY(0); }

.button__meta {
  font-size: 0.78rem;
  font-weight: 400;
  opacity: 0.85;
}

/* --- Features --- */
.features {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 72px 24px;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 20px;
}

.feature {
  background: var(--card);
  border-radius: var(--radius);
  padding: 28px;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.06), 0 8px 24px rgba(30, 32, 48, 0.05);
}

.feature h2 {
  margin: 0 0 8px;
  font-size: 1.15rem;
}

.feature p {
  margin: 0;
  color: var(--muted);
  font-size: 0.97rem;
}

.feature code {
  background: #eef0f6;
  padding: 1px 5px;
  border-radius: 5px;
  font-size: 0.88em;
}

/* --- Footer --- */
.footer {
  text-align: center;
  padding: 40px 24px 56px;
  color: var(--muted);
  font-size: 0.9rem;
}

.footer a { text-decoration: none; }
.footer a:hover { text-decoration: underline; }
.footer__copy { margin-top: 8px; opacity: 0.8; }

@media (max-width: 480px) {
  .hero__title { font-size: 2.4rem; }
  .hero { padding-top: 56px; }
}