:root {
  --demo-bg: #f5f7fb;
  --demo-panel: #ffffff;
  --demo-line: #dfe7f2;
  --demo-text: #172033;
  --demo-muted: #5f6c85;
  --demo-accent: #2e7ff7;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: 'Segoe UI', Arial, sans-serif;
  background:
    radial-gradient(circle at top right, rgba(46, 127, 247, 0.1), transparent 25%),
    linear-gradient(180deg, #f8faff 0%, var(--demo-bg) 100%);
  color: var(--demo-text);
  padding: 48px 24px 96px;
}

.demo-shell {
  max-width: 1040px;
  margin: 0 auto;
}

.intro {
  max-width: 760px;
}

.eyebrow {
  display: inline-block;
  margin-bottom: 12px;
  font-size: 12px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--demo-accent);
}

h1 {
  margin: 0 0 14px;
  font-size: clamp(36px, 5vw, 58px);
  line-height: 1;
}

p {
  margin: 0;
  font-size: 18px;
  line-height: 1.6;
  color: var(--demo-muted);
}

.demo-grid {
  margin-top: 28px;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 16px;
}

.demo-card {
  display: grid;
  gap: 10px;
  padding: 22px;
  border-radius: 22px;
  border: 1px solid var(--demo-line);
  background: rgba(255, 255, 255, 0.84);
  box-shadow: 0 18px 40px rgba(23, 32, 51, 0.06);
  text-decoration: none;
  transition:
    transform 160ms ease,
    border-color 160ms ease,
    box-shadow 160ms ease;
}

.demo-card:hover {
  transform: translateY(-2px);
  border-color: rgba(46, 127, 247, 0.4);
  box-shadow: 0 20px 42px rgba(23, 32, 51, 0.1);
}

.demo-card strong {
  font-size: 18px;
}

.demo-card span {
  color: var(--demo-muted);
  line-height: 1.5;
}

.demo-card.active {
  background: linear-gradient(180deg, #eef5ff 0%, #ffffff 100%);
}

#demo-chat-container {
  position: fixed;
  bottom: 16px;
  right: 16px;
}

@media (max-width: 720px) {
  body {
    padding: 36px 18px 96px;
  }

  p {
    font-size: 16px;
  }
}