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

body {
  font-family: "Segoe UI", "Inter", Arial, sans-serif;
  color: #1b1f24;
  background: #f7f7fb;
  line-height: 1.6;
}

a {
  color: inherit;
  text-decoration: none;
}

.container {
  width: min(1100px, 92%);
  margin: 0 auto;
}

.narrow {
  width: min(820px, 92%);
  margin: 0 auto;
}

.site-header {
  background: #ffffff;
  border-bottom: 1px solid #e5e7eb;
  padding: 16px 0;
}

.brand {
  font-weight: 700;
  font-size: 1.1rem;
}

.nav {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 10px;
}

.nav a {
  padding: 6px 10px;
  border-radius: 999px;
  font-size: 0.95rem;
  background: #f1f5f9;
}

.nav a.active {
  background: #1d4ed8;
  color: #ffffff;
}

.hero {
  padding: 64px 0;
  background: linear-gradient(135deg, #dbeafe, #f5f3ff);
}

.hero h1 {
  font-size: 2rem;
  margin-bottom: 12px;
}

.hero p {
  max-width: 640px;
  margin-bottom: 20px;
}

.hero-actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

.button {
  background: #1d4ed8;
  color: #ffffff;
  padding: 10px 18px;
  border-radius: 10px;
  font-weight: 600;
}

.button-outline {
  background: transparent;
  border: 2px solid #1d4ed8;
  color: #1d4ed8;
}

.section {
  padding: 48px 0;
}

.grid-3 {
  display: grid;
  gap: 20px;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
}

.card {
  background: #ffffff;
  padding: 22px;
  border-radius: 16px;
  box-shadow: 0 10px 25px rgba(15, 23, 42, 0.08);
  margin-bottom: 20px;
}

.stack .card:last-child {
  margin-bottom: 0;
}

.lead {
  margin: 16px 0 24px;
  font-size: 1.05rem;
}

.list {
  margin: 10px 0 0 18px;
}

.tabs {
  display: flex;
  gap: 12px;
  margin: 20px 0;
}

.tab {
  padding: 10px 16px;
  border: none;
  border-radius: 12px;
  background: #e2e8f0;
  cursor: pointer;
  font-weight: 600;
}

.tab.active {
  background: #1d4ed8;
  color: #ffffff;
}

.tab-panel {
  display: none;
}

.tab-panel.active {
  display: block;
}

.chat {
  margin-top: 16px;
}

.chat-log {
  display: flex;
  flex-direction: column;
  gap: 10px;
  background: #f8fafc;
  padding: 16px;
  border-radius: 12px;
  min-height: 180px;
}

.chat-message {
  padding: 10px 12px;
  border-radius: 12px;
  max-width: 80%;
  font-size: 0.95rem;
}

.chat-message.user {
  align-self: flex-end;
  background: #dbeafe;
}

.chat-message.bot {
  align-self: flex-start;
  background: #fef3c7;
}

.chat-form {
  display: flex;
  gap: 10px;
  margin-top: 12px;
}

.chat-form input {
  flex: 1;
  padding: 10px 12px;
  border-radius: 10px;
  border: 1px solid #cbd5f5;
}

.chat-form button {
  padding: 10px 16px;
  border-radius: 10px;
  border: none;
  background: #1d4ed8;
  color: #ffffff;
  font-weight: 600;
  cursor: pointer;
}

.chat-note {
  font-size: 0.9rem;
  margin-top: 8px;
  color: #475569;
}

.disclaimer {
  background: #fee2e2;
  color: #7f1d1d;
  padding: 12px;
  border-radius: 10px;
  margin: 12px 0;
  font-weight: 600;
}

.site-footer {
  background: #0f172a;
  color: #e2e8f0;
  padding: 24px 0;
  font-size: 0.9rem;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}

@media (max-width: 700px) {
  .nav {
    gap: 8px;
  }

  .nav a {
    font-size: 0.85rem;
  }

  .chat-form {
    flex-direction: column;
  }

  .chat-message {
    max-width: 100%;
  }
}