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

body {
  font-family:
    -apple-system, BlinkMacSystemFont, "Segoe UI", "Malgun Gothic", sans-serif;
  background: #0f0f14;
  color: #e8e8ec;
  line-height: 1.6;
}

/* Header */
.header {
  position: sticky;
  top: 0;
  background: rgba(15, 15, 20, 0.9);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid #22222c;
  z-index: 100;
}

.header-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 1rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-size: 1.5rem;
  font-weight: 700;
  background: linear-gradient(135deg, #6b9eff, #b88cff);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.header nav {
  display: flex;
  gap: 2rem;
}

.header nav a {
  color: #a0a0b0;
  text-decoration: none;
  font-size: 0.95rem;
  transition: color 0.2s;
}

.header nav a:hover {
  color: #e8e8ec;
}

/* Hero */
.hero {
  max-width: 800px;
  margin: 0 auto;
  padding: 6rem 2rem 5rem;
  text-align: center;
}

.hero h2 {
  font-size: 3rem;
  font-weight: 700;
  margin-bottom: 1.5rem;
  line-height: 1.2;
}

.hero-sub {
  font-size: 1.15rem;
  color: #a0a0b0;
  margin-bottom: 2.5rem;
}

.hero-note {
  margin-top: 1.5rem;
  font-size: 0.9rem;
  color: #707080;
}

/* Button */
.btn-primary {
  display: inline-block;
  background: linear-gradient(135deg, #6b9eff, #b88cff);
  color: #fff;
  padding: 0.9rem 2.5rem;
  border-radius: 8px;
  text-decoration: none;
  font-weight: 600;
  font-size: 1rem;
  transition:
    transform 0.2s,
    box-shadow 0.2s;
  border: none;
  cursor: pointer;
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(107, 158, 255, 0.3);
}

/* Sections */
section {
  max-width: 1100px;
  margin: 0 auto;
  padding: 4rem 2rem;
}

section h2 {
  font-size: 2rem;
  margin-bottom: 2.5rem;
  text-align: center;
}

/* Features */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1.5rem;
}

.feature-card {
  background: #1a1a22;
  border: 1px solid #22222c;
  border-radius: 12px;
  padding: 2rem 1.5rem;
  transition:
    border-color 0.2s,
    transform 0.2s;
}

.feature-card:hover {
  border-color: #3a3a4a;
  transform: translateY(-2px);
}

.feature-card h3 {
  font-size: 1.15rem;
  margin-bottom: 0.75rem;
  color: #b88cff;
}

.feature-card p {
  color: #9090a0;
  font-size: 0.95rem;
}

/* Download */
.download {
  text-align: center;
  background: #1a1a22;
  border-radius: 16px;
  margin: 4rem auto;
  max-width: 700px;
}

.download p {
  color: #a0a0b0;
  margin-bottom: 1.5rem;
}

.download-note {
  margin-top: 1rem;
  font-size: 0.9rem;
  color: #707080;
}

/* Notice */
.notice {
  max-width: 800px;
}

.notice p {
  color: #9090a0;
  margin-bottom: 1rem;
  font-size: 0.95rem;
}

.notice strong {
  color: #e8e8ec;
}

/* Footer */
.footer {
  border-top: 1px solid #22222c;
  padding: 2.5rem 2rem;
  text-align: center;
  color: #707080;
  font-size: 0.9rem;
}

.footer-small {
  margin-top: 0.5rem;
  font-size: 0.8rem;
  color: #505060;
}

/* Mobile */
@media (max-width: 640px) {
  .header-inner {
    padding: 1rem;
  }

  .header nav {
    gap: 1rem;
  }

  .hero {
    padding: 4rem 1.5rem 3rem;
  }

  .hero h2 {
    font-size: 2rem;
  }

  section {
    padding: 3rem 1.5rem;
  }

  section h2 {
    font-size: 1.5rem;
  }
}