:root {
  --blue: #2563eb;
  --blue-dark: #1d4ed8;
  --green: #22c55e;
  --yellow: #f59e0b;
  --red: #ef4444;
  --gray-50: #f9fafb;
  --gray-100: #f3f4f6;
  --gray-200: #e5e7eb;
  --gray-500: #6b7280;
  --gray-700: #374151;
  --gray-900: #111827;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background: var(--gray-50);
  color: var(--gray-900);
  line-height: 1.6;
}

.container {
  max-width: 680px;
  margin: 0 auto;
  padding: 0 24px;
}

.nav {
  padding: 20px 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-install {
  font-size: 14px;
  font-weight: 600;
  color: var(--blue);
  text-decoration: none;
  padding: 8px 16px;
  border: 1.5px solid var(--blue);
  border-radius: 8px;
}

.nav-install:hover {
  background: var(--blue);
  color: #fff;
}

.logo {
  font-size: 18px;
  font-weight: 700;
}

.hero {
  text-align: center;
  padding: 60px 0 40px;
}

.hero h1 {
  font-size: 40px;
  line-height: 1.2;
  margin-bottom: 16px;
}

.highlight {
  color: var(--blue);
}

.subtitle {
  font-size: 17px;
  color: var(--gray-500);
  max-width: 480px;
  margin: 0 auto 28px;
}

.price-box {
  display: flex;
  align-items: baseline;
  justify-content: center;
  gap: 8px;
  margin-bottom: 20px;
}

.price {
  font-size: 36px;
  font-weight: 700;
}

.price-note {
  font-size: 14px;
  color: var(--gray-500);
}

.btn-primary {
  display: inline-block;
  padding: 14px 32px;
  font-size: 16px;
  font-weight: 600;
  color: #fff;
  background: var(--blue);
  border: none;
  border-radius: 10px;
  cursor: pointer;
  transition: background 0.15s;
}

.btn-primary:hover {
  background: var(--blue-dark);
}

.btn-primary:disabled {
  background: var(--gray-500);
  cursor: not-allowed;
}

.checkout-form {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
}

#email-input {
  width: 320px;
  max-width: 100%;
  padding: 12px 16px;
  font-size: 15px;
  border: 1px solid var(--gray-200);
  border-radius: 10px;
}

#email-input:focus {
  outline: none;
  border-color: var(--blue);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
}

.checkout-msg {
  font-size: 13px;
  color: var(--red);
  min-height: 18px;
}

.demo {
  padding: 40px 0;
}

.demo h2, .faq h2 {
  font-size: 22px;
  margin-bottom: 20px;
  text-align: center;
}

.demo-box {
  display: flex;
  gap: 16px;
  align-items: stretch;
}

.demo-input, .demo-output {
  flex: 1;
  background: #fff;
  border: 1px solid var(--gray-200);
  border-radius: 10px;
  padding: 16px;
}

.demo-label {
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  color: var(--gray-500);
  letter-spacing: 0.5px;
}

.demo-input p, .demo-summary {
  font-size: 14px;
  color: var(--gray-700);
  margin-top: 8px;
  line-height: 1.5;
}

.demo-arrow {
  display: flex;
  align-items: center;
  font-size: 24px;
  color: var(--gray-500);
}

.demo-badge {
  display: inline-block;
  font-size: 11px;
  font-weight: 600;
  padding: 2px 8px;
  border-radius: 999px;
  color: #fff;
  margin-top: 8px;
}

.demo-badge.medium { background: var(--yellow); }

.demo-flags {
  margin-top: 10px;
  padding-left: 16px;
  font-size: 13px;
  color: var(--gray-700);
}

.demo-flags li { margin-bottom: 2px; }

.try-it {
  padding: 40px 0;
}

.try-it h2 {
  font-size: 22px;
  margin-bottom: 6px;
  text-align: center;
}

.try-it .subtitle {
  text-align: center;
  margin-bottom: 20px;
}

#demo-input {
  width: 100%;
  min-height: 120px;
  padding: 14px 16px;
  font-size: 14px;
  font-family: inherit;
  border: 1px solid var(--gray-200);
  border-radius: 10px;
  resize: vertical;
  background: #fff;
}

#demo-input:focus {
  outline: none;
  border-color: var(--blue);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
}

.try-it-row {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-top: 12px;
}

.try-it-row .checkout-msg {
  flex: 1;
}

.try-it .demo-output {
  margin-top: 16px;
}

.demo-badge.low { background: var(--green); }
.demo-badge.medium { background: var(--yellow); }
.demo-badge.high { background: var(--orange, #ea580c); }
.demo-badge.critical { background: var(--red); }

.faq {
  padding: 40px 0;
}

details {
  background: #fff;
  border: 1px solid var(--gray-200);
  border-radius: 8px;
  margin-bottom: 8px;
  overflow: hidden;
}

summary {
  padding: 14px 16px;
  font-size: 15px;
  font-weight: 500;
  cursor: pointer;
  list-style: none;
}

summary::before {
  content: "+ ";
  color: var(--gray-500);
}

details[open] summary::before {
  content: "− ";
}

details p {
  padding: 0 16px 14px;
  font-size: 14px;
  color: var(--gray-500);
}

.footer {
  text-align: center;
  padding: 40px 0;
  font-size: 13px;
  color: var(--gray-500);
  border-top: 1px solid var(--gray-200);
  margin-top: 20px;
}