:root {
  --color-bg: #ffffff;
  --color-text: #1a1a1a;
  --color-text-muted: #555555;
  --color-accent: #2563eb;
  --color-accent-hover: #1d4ed8;
  --color-border: #e5e7eb;
  --color-surface: #f9fafb;
  --color-cta: #2563eb;
  --color-cta-hover: #1d4ed8;
  --color-cta-text: #ffffff;
  --font-sans: "Helvetica Neue", Arial, "Hiragino Kaku Gothic ProN", "Hiragino Sans", Meiryo, sans-serif;
  --max-width: 720px;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--color-accent);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* ── Header ── */

.site-header {
  padding: 2rem 0 1rem;
  text-align: center;
  border-bottom: 1px solid var(--color-border);
}

.brand {
  font-size: 0.85rem;
  font-weight: 600;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin-bottom: 0.25rem;
}

.product-name {
  font-size: 1.75rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  line-height: 1.3;
}

/* ── Hero ── */

.hero {
  text-align: center;
  padding: 3rem 0 2.5rem;
}

.hero-tagline {
  font-size: 1.15rem;
  color: var(--color-text-muted);
  max-width: 560px;
  margin: 0 auto;
}

/* ── Section common ── */

section {
  padding: 2.5rem 0;
}

.section-title {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 1.25rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--color-accent);
  display: inline-block;
}

/* ── Benefits ── */

.benefits-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.benefits-list li {
  padding: 1.25rem 1.5rem;
  background: var(--color-surface);
  border-radius: 8px;
  border-left: 4px solid var(--color-accent);
  line-height: 1.6;
}

.benefits-list li strong {
  display: block;
  margin-bottom: 0.25rem;
}

/* ── CTA / Purchase ── */

.cta-section {
  text-align: center;
  padding: 2.5rem 0;
}

.cta-button {
  display: inline-block;
  padding: 1rem 3rem;
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--color-cta-text);
  background: var(--color-cta);
  border-radius: 8px;
  transition: background 0.2s ease;
}

.cta-button:hover {
  background: var(--color-cta-hover);
  text-decoration: none;
}

.cta-note {
  margin-top: 0.75rem;
  font-size: 0.85rem;
  color: var(--color-text-muted);
}

/* ── License Info ── */

.license-list {
  list-style: none;
}

.license-list li {
  padding: 0.5rem 0;
  padding-left: 1.5rem;
  position: relative;
}

.license-list li::before {
  content: "—";
  position: absolute;
  left: 0;
  color: var(--color-text-muted);
}

/* ── FAQ ── */

.faq-item {
  margin-bottom: 1.5rem;
}

.faq-item dt {
  font-weight: 700;
  margin-bottom: 0.25rem;
}

.faq-item dt::before {
  content: "Q. ";
  color: var(--color-accent);
}

.faq-item dd {
  padding-left: 1.5rem;
  color: var(--color-text-muted);
}

.faq-item dd::before {
  content: "A. ";
  color: var(--color-text);
  font-weight: 600;
}

/* ── Support ── */

.support-section {
  text-align: center;
  padding: 2rem 0;
  background: var(--color-surface);
  border-radius: 8px;
}

.support-section p {
  margin-bottom: 0.5rem;
}

/* ── Footer ── */

.site-footer {
  border-top: 1px solid var(--color-border);
  padding: 2rem 0;
  text-align: center;
  font-size: 0.85rem;
  color: var(--color-text-muted);
}

.footer-links {
  list-style: none;
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 0.5rem 1.5rem;
  margin-bottom: 1rem;
}

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

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

/* ── Legal pages ── */

.legal-page {
  padding: 3rem 0;
}

.legal-page h1 {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 1.5rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--color-accent);
}

.legal-page .placeholder-notice {
  padding: 1.5rem;
  background: #fef3c7;
  border: 1px solid #f59e0b;
  border-radius: 8px;
  color: #92400e;
  margin-bottom: 2rem;
}

.legal-page .back-link {
  display: inline-block;
  margin-top: 2rem;
}

/* ── Responsive ── */

@media (max-width: 600px) {
  html {
    font-size: 15px;
  }

  .site-header {
    padding: 1.5rem 0 0.75rem;
  }

  .product-name {
    font-size: 1.4rem;
  }

  .hero {
    padding: 2rem 0 1.5rem;
  }

  .hero-tagline {
    font-size: 1.05rem;
  }

  section {
    padding: 2rem 0;
  }

  .benefits-list li {
    padding: 1rem 1.25rem;
  }

  .cta-button {
    display: block;
    text-align: center;
    padding: 1rem 1.5rem;
  }

  .footer-links {
    flex-direction: column;
    gap: 0.75rem;
  }
}