:root {
  --bg: #ffffff;
  --bg-alt: #f6f7f9;
  --text: #0f172a;
  --text-soft: #475569;
  --text-muted: #94a3b8;
  --brand: #2670ac;
  --brand-strong: #1e5e94;
  --accent: #f7a427;
  --accent-strong: #e88e0d;
  --border: #e5e7eb;
  --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.06);
  --shadow-md: 0 6px 24px rgba(15, 23, 42, 0.08);
  --shadow-lg: 0 24px 60px rgba(15, 23, 42, 0.12);
  --radius: 14px;
  --radius-lg: 22px;
  --maxw: 1080px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0b1220;
    --bg-alt: #0f172a;
    --text: #e8edf5;
    --text-soft: #b6c2d4;
    --text-muted: #7e8aa0;
    --border: #1f2a3d;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.5);
    --shadow-md: 0 6px 24px rgba(0, 0, 0, 0.5);
    --shadow-lg: 0 24px 60px rgba(0, 0, 0, 0.6);
  }
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "Helvetica Neue",
    "Hiragino Sans", "Yu Gothic UI", "Meiryo", system-ui, sans-serif;
  font-size: 17px;
  line-height: 1.6;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

.container {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 24px;
}

a { color: var(--brand); text-decoration: none; }
a:hover { text-decoration: underline; }

h1, h2, h3 { letter-spacing: -0.02em; line-height: 1.2; margin: 0; }
h1 { font-size: clamp(2.2rem, 5vw, 3.5rem); font-weight: 800; }
h2 { font-size: clamp(1.6rem, 3.2vw, 2.2rem); font-weight: 700; margin-bottom: 1.5rem; }
h3 { font-size: 1.15rem; font-weight: 700; }

p { margin: 0.5rem 0; color: var(--text-soft); }

code {
  font-family: ui-monospace, SF Mono, Menlo, Consolas, monospace;
  background: var(--bg-alt);
  padding: 0.1em 0.4em;
  border-radius: 6px;
  font-size: 0.92em;
}

/* Top bar */
.topbar {
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: saturate(180%) blur(14px);
  -webkit-backdrop-filter: saturate(180%) blur(14px);
  background: rgba(255, 255, 255, 0.7);
  border-bottom: 1px solid var(--border);
}
@media (prefers-color-scheme: dark) {
  .topbar { background: rgba(11, 18, 32, 0.7); }
}
.topbar-row {
  display: flex; align-items: center; justify-content: space-between;
  height: 64px;
}
.brand {
  display: inline-flex; align-items: center; gap: 10px;
  color: var(--text); font-weight: 700; letter-spacing: -0.01em;
}
.brand img { border-radius: 8px; }
.nav { display: flex; align-items: center; gap: 22px; }
.nav a { color: var(--text-soft); font-size: 0.95rem; }
.nav a:hover { color: var(--text); text-decoration: none; }
.lang-toggle {
  font: inherit; font-size: 0.9rem;
  background: var(--bg-alt); color: var(--text);
  border: 1px solid var(--border); border-radius: 999px;
  padding: 6px 14px; cursor: pointer;
}
.lang-toggle:hover { border-color: var(--brand); color: var(--brand); }

/* Hero */
.hero {
  padding: 80px 0 60px;
  background: radial-gradient(1200px 400px at 50% -100px, rgba(38, 112, 172, 0.12), transparent 60%);
}
.hero-grid {
  display: grid; grid-template-columns: 1.1fr 0.9fr; gap: 48px; align-items: center;
}
@media (max-width: 800px) {
  .hero-grid { grid-template-columns: 1fr; text-align: center; }
  .hero-art { order: -1; }
}
.lede {
  font-size: 1.2rem;
  color: var(--text-soft);
  margin: 1rem 0 1.5rem;
  max-width: 36ch;
}
.hero-grid .lede { max-width: 36ch; }
@media (max-width: 800px) {
  .hero-grid .lede { margin-left: auto; margin-right: auto; }
}
.hero-art img {
  width: clamp(180px, 30vw, 280px);
  height: auto;
  filter: drop-shadow(0 30px 60px rgba(38, 112, 172, 0.35));
  border-radius: 24px;
}
.cta-row { display: flex; align-items: center; gap: 16px; flex-wrap: wrap; }
@media (max-width: 800px) {
  .cta-row { justify-content: center; }
}
.cta-meta { color: var(--text-muted); font-size: 0.95rem; }

/* Buttons */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  font: inherit; font-weight: 600;
  padding: 12px 22px; border-radius: 999px;
  border: 1px solid transparent; cursor: pointer;
  transition: transform 0.05s ease, box-shadow 0.2s ease, background 0.2s ease;
  text-decoration: none;
}
.btn:hover { text-decoration: none; transform: translateY(-1px); }
.btn-primary {
  background: var(--accent); color: #1a1006;
  box-shadow: 0 8px 20px rgba(247, 164, 39, 0.35);
}
.btn-primary:hover { background: var(--accent-strong); color: #1a1006; }
.btn-lg { padding: 14px 28px; font-size: 1.05rem; }

/* Features */
.features { padding: 80px 0; background: var(--bg-alt); }
.feature-grid {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px;
}
@media (max-width: 900px) { .feature-grid { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 520px) { .feature-grid { grid-template-columns: 1fr; } }
.feature {
  background: var(--bg);
  padding: 24px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
}
.feature-icon { font-size: 1.8rem; margin-bottom: 8px; }
.feature h3 { margin-bottom: 6px; }
.feature p { font-size: 0.97rem; }

/* How it works */
.how { padding: 80px 0; }
.steps {
  list-style: none; padding: 0; margin: 0;
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px;
}
@media (max-width: 800px) { .steps { grid-template-columns: 1fr; } }
.steps li {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  position: relative;
}
.step-num {
  display: inline-flex; align-items: center; justify-content: center;
  width: 32px; height: 32px; border-radius: 999px;
  background: var(--brand); color: white;
  font-weight: 700; margin-bottom: 12px;
}

/* Screenshot */
.screenshot { padding: 0 0 80px; }
.screenshot img {
  width: 100%;
  max-width: 480px;
  display: block;
  margin: 0 auto;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  border: 1px solid var(--border);
}

/* Buy */
.buy { padding: 80px 0; background: var(--bg-alt); }
.buy-card {
  max-width: 560px;
  margin: 0 auto;
  text-align: center;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 40px 32px;
  box-shadow: var(--shadow-md);
}
.price {
  display: flex; align-items: baseline; justify-content: center; gap: 12px;
  margin-bottom: 12px;
}
.price-amount {
  font-size: 3rem; font-weight: 800; letter-spacing: -0.03em;
  color: var(--brand);
}
.price-meta { color: var(--text-muted); font-size: 0.95rem; }
.buy h2 { margin: 8px 0 4px; }
.buy p { margin-bottom: 20px; }
.buy-specs {
  list-style: none; padding: 0; margin: 24px 0 0;
  display: flex; flex-direction: column; gap: 6px;
  color: var(--text-muted); font-size: 0.92rem;
}

/* FAQ */
.faq { padding: 80px 0 100px; }
.faq h2 { text-align: center; margin-bottom: 32px; }
.faq details {
  border-top: 1px solid var(--border);
  padding: 18px 4px;
}
.faq details:last-of-type { border-bottom: 1px solid var(--border); }
.faq summary {
  cursor: pointer; font-weight: 600; color: var(--text);
  list-style: none;
  display: flex; align-items: center; justify-content: space-between;
}
.faq summary::after {
  content: "+"; font-size: 1.4rem; color: var(--text-muted);
  transition: transform 0.2s ease;
}
.faq details[open] summary::after { content: "−"; }
.faq details p { margin-top: 10px; }

/* Footer */
.footer {
  border-top: 1px solid var(--border);
  padding: 28px 0;
  color: var(--text-muted);
  font-size: 0.9rem;
}
.footer-row { display: flex; align-items: center; justify-content: space-between; gap: 16px; }
.footer-links a { color: var(--text-muted); }
.footer-links a:hover { color: var(--text); }

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; }
}