:root {
  --bg-color: #0d0e10;
  --card-bg: #16181c;
  --border-color: #22252a;
  --text-primary: #f5f5f7;
  --text-secondary: #86868b;
  --text-muted: #6e7681;
  --accent-blue: #0071e3;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
}

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

body {
  font-family: var(--font-sans);
  background-color: var(--bg-color);
  color: var(--text-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

.container {
  max-width: 800px;
  margin: 0 auto;
  padding: 0 24px;
}

/* Header */
header {
  padding: 20px 0;
  border-bottom: 1px solid var(--border-color);
}

.header-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-size: 1.2rem;
  font-weight: 700;
  letter-spacing: -0.5px;
}

.nav-links a {
  color: var(--text-secondary);
  text-decoration: none;
  margin-left: 20px;
  font-size: 0.85rem;
  transition: color 0.2s;
}

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

/* Hero Section (Centered 1-Column Layout) */
.hero {
  padding: 80px 0;
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.app-icon {
  width: 96px;
  height: 96px;
  border-radius: 22px;
  margin-bottom: 32px;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.4);
}

.hero-text {
  max-width: 640px;
}

.hero-text h1 {
  font-size: 3.2rem;
  font-weight: 700;
  line-height: 1.3;
  margin-bottom: 24px;
  letter-spacing: -1px;
}

.hero-text p.lead {
  font-size: 1.1rem;
  color: var(--text-secondary);
  margin-bottom: 40px;
  font-weight: 400;
  margin-top: 1em;
}

.hero-cta {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  margin-bottom: 40px;
}

.btn-download {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 12px 28px;
  background: var(--text-primary);
  color: var(--bg-color);
  font-weight: 600;
  font-size: 0.95rem;
  text-decoration: none;
  border-radius: 8px;
  transition: opacity 0.2s;
}

.btn-download:hover {
  opacity: 0.9;
}

.btn-download svg {
  fill: currentColor;
  width: 18px;
  height: 18px;
}

.download-meta {
  font-size: 0.75rem;
  color: var(--text-muted);
}

/* Features Section (Minimal Border Layout) */
.features-section {
  padding: 60px 0;
  border-top: 1px solid var(--border-color);
}

.section-title {
  text-align: center;
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 40px;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 32px;
}

.feature-card {
  padding: 8px 0;
}

.feature-header {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 12px;
}

.feature-icon {
  font-size: 1.25rem;
}

.feature-card h3 {
  font-size: 1.05rem;
  font-weight: 600;
}

.feature-card p {
  color: var(--text-secondary);
  font-size: 0.85rem;
  line-height: 1.5;
}

/* Install Guide Section */
.setup-section {
  padding: 60px 0;
  border-top: 1px solid var(--border-color);
}

.setup-container {
  display: flex;
  flex-direction: column;
  gap: 40px;
}

.setup-steps h3, .security-info h3 {
  font-size: 1.25rem;
  margin-bottom: 20px;
  font-weight: 600;
}

.steps-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.step-item {
  display: flex;
  gap: 16px;
}

.step-num {
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: var(--border-color);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 600;
  font-size: 0.8rem;
  color: var(--text-primary);
  flex-shrink: 0;
}

.step-text h4 {
  font-size: 0.95rem;
  margin-bottom: 2px;
}

.step-text p {
  color: var(--text-secondary);
  font-size: 0.85rem;
}

.security-box {
  background: rgba(255, 71, 87, 0.01);
  border: 1px solid rgba(255, 71, 87, 0.1);
  border-radius: 8px;
  padding: 20px;
}

.security-box p {
  color: var(--text-secondary);
  font-size: 0.85rem;
  margin-bottom: 12px;
  line-height: 1.5;
}

.security-box p strong {
  color: var(--text-primary);
}

.security-box p:last-child {
  margin-bottom: 0;
}

/* Footer */
footer {
  padding: 40px 0;
  border-top: 1px solid var(--border-color);
  font-size: 0.75rem;
}

.footer-disclaimer {
  color: var(--text-muted);
  line-height: 1.5;
  margin-bottom: 16px;
}

.footer-links {
  margin-bottom: 16px;
}

.footer-links a {
  color: var(--text-secondary);
  text-decoration: none;
  margin-right: 16px;
}

.footer-links a:hover {
  color: var(--text-primary);
}

.footer-copyright {
  color: var(--text-muted);
}