:root {
  --blue: #4A90D9;
  --dark: #1a1a1a;
  --muted: #666;
  --light: #fafafa;
  --border: #e8e8e8;
  --white: #fff;
  --green: #1a7f37;
  --green-bg: #ddf4dd;
  --red: #cf222e;
  --red-bg: #ffebe9;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  color: var(--dark);
  background: var(--white);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

/* --- Nav --- */

nav {
  max-width: 960px;
  margin: 0 auto;
  padding: 20px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  font-size: 15px;
  font-weight: 600;
  color: var(--dark);
  text-decoration: none;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 24px;
}

.nav-links a {
  font-size: 14px;
  color: var(--muted);
  text-decoration: none;
}

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

/* --- Buttons --- */

.btn {
  display: inline-block;
  background: var(--dark);
  color: var(--white);
  padding: 10px 24px;
  border-radius: 8px;
  font-size: 14px;
  font-weight: 500;
  text-decoration: none;
  transition: background 0.15s;
}

.btn:hover {
  background: #333;
  color: var(--white);
}

.btn-lg {
  padding: 14px 32px;
  font-size: 16px;
  border-radius: 10px;
}

.btn-sm {
  padding: 6px 16px;
  font-size: 13px;
}

/* --- Hero --- */

.hero {
  max-width: 960px;
  margin: 0 auto;
  padding: 80px 24px 60px;
  text-align: center;
}

.hero h1 {
  font-size: 56px;
  font-weight: 700;
  letter-spacing: -0.035em;
  line-height: 1.08;
  margin-bottom: 24px;
}

.hero-sub {
  font-size: 19px;
  color: var(--muted);
  max-width: 540px;
  margin: 0 auto 40px;
  line-height: 1.5;
}

/* --- Demo --- */

.demo {
  max-width: 720px;
  margin: 0 auto 40px;
  padding: 0 24px;
}

.demo-window {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 8px 40px rgba(0, 0, 0, 0.06), 0 1px 3px rgba(0, 0, 0, 0.04);
}

.demo-bar {
  background: var(--light);
  padding: 12px 16px;
  display: flex;
  gap: 6px;
  border-bottom: 1px solid var(--border);
}

.demo-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: #ddd;
}

.demo-content {
  padding: 28px 32px;
  font-size: 15px;
  line-height: 1.9;
}

.demo-line {
  margin-bottom: 6px;
}

.demo-line.dim {
  color: #999;
}

.wc-del {
  background: var(--red-bg);
  color: var(--red);
  text-decoration: line-through;
  border-radius: 2px;
  padding: 1px 3px;
}

.wc-ins {
  background: var(--green-bg);
  color: var(--green);
  text-decoration: none;
  border-radius: 2px;
  padding: 1px 3px;
}

/* --- Sections --- */

.section {
  max-width: 960px;
  margin: 0 auto;
  padding: 80px 24px;
}

.section-alt {
  background: var(--light);
  max-width: 100%;
}

.section-alt > h2,
.section-alt > .use-cases {
  max-width: 960px;
  margin-left: auto;
  margin-right: auto;
}

.section h2 {
  font-size: 32px;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 48px;
  text-align: center;
}

/* --- Steps --- */

.steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 48px;
}

.step {
  text-align: center;
}

.step-num {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--blue);
  color: var(--white);
  font-size: 16px;
  font-weight: 600;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 16px;
}

.step h3 {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 8px;
}

.step p {
  font-size: 15px;
  color: var(--muted);
}

/* --- Features --- */

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.feature {
  padding: 24px;
  border: 1px solid var(--border);
  border-radius: 12px;
  background: var(--white);
}

.feature h3 {
  font-size: 15px;
  font-weight: 600;
  margin-bottom: 8px;
}

.feature p {
  font-size: 14px;
  color: var(--muted);
  line-height: 1.5;
}

/* --- Use cases --- */

.use-cases {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
  padding: 0 24px;
}

.use-case h3 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 8px;
}

.use-case p {
  font-size: 14px;
  color: var(--muted);
  line-height: 1.5;
}

/* --- Privacy / centered text --- */

.centered-text {
  max-width: 600px;
  margin: 0 auto;
  text-align: center;
  font-size: 16px;
  color: var(--muted);
  line-height: 1.6;
}

.centered-text a {
  color: var(--blue);
  text-decoration: none;
}

.centered-text a:hover {
  text-decoration: underline;
}

/* --- Prose (privacy policy page) --- */

.prose {
  max-width: 640px;
  margin: 0 auto;
}

.prose h1 {
  font-size: 32px;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 8px;
}

.prose .last-updated {
  font-size: 13px;
  color: var(--muted);
  margin-bottom: 40px;
}

.prose h2 {
  font-size: 18px;
  font-weight: 600;
  margin-top: 36px;
  margin-bottom: 12px;
  text-align: left;
}

.prose p {
  font-size: 15px;
  color: #444;
  line-height: 1.7;
  margin-bottom: 12px;
}

.prose ul {
  margin-bottom: 12px;
  padding-left: 24px;
}

.prose li {
  font-size: 15px;
  color: #444;
  line-height: 1.7;
  margin-bottom: 4px;
}

.prose a {
  color: var(--blue);
  text-decoration: none;
}

.prose a:hover {
  text-decoration: underline;
}

/* --- Footer --- */

footer {
  border-top: 1px solid var(--border);
  padding: 40px 24px;
}

.footer-inner {
  max-width: 960px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 13px;
  color: var(--muted);
}

.footer-links {
  display: flex;
  gap: 24px;
}

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

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

/* --- Responsive --- */

@media (max-width: 768px) {
  .hero h1 {
    font-size: 36px;
  }

  .hero-sub {
    font-size: 17px;
  }

  .steps,
  .features-grid,
  .use-cases {
    grid-template-columns: 1fr;
    gap: 20px;
  }

  .section {
    padding: 60px 24px;
  }

  .demo-content {
    padding: 20px;
    font-size: 14px;
  }

  .footer-inner {
    flex-direction: column;
    gap: 16px;
    text-align: center;
  }

  .nav-links {
    gap: 16px;
  }

  .gh-link {
    display: none;
  }
}