:root {
  --bg: #0f1419;
  --surface: #1a2332;
  --text: #e8ecf1;
  --muted: #8b9cb0;
  --accent: #ff6b4a;
  --accent-soft: rgba(255, 107, 74, 0.15);
  --border: rgba(255, 255, 255, 0.08);
  --radius: 12px;
  --font: "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Noto Sans JP", system-ui, sans-serif;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
}

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

a:hover {
  text-decoration: underline;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.75rem 1.25rem;
  background: rgba(15, 20, 25, 0.85);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}

.site-logo {
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--text);
  text-decoration: none;
}

.site-logo:hover {
  text-decoration: none;
  color: var(--accent);
}

.site-nav {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
  justify-content: flex-end;
}

.site-nav a {
  font-size: 0.875rem;
  color: var(--muted);
}

.site-nav a:hover {
  color: var(--text);
}

main {
  max-width: 720px;
  margin: 0 auto;
  padding: 2rem 1.25rem 4rem;
}

main.wide {
  max-width: 960px;
}

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

.hero h1 {
  margin: 0 0 0.75rem;
  font-size: clamp(1.75rem, 5vw, 2.5rem);
  font-weight: 800;
  letter-spacing: -0.02em;
}

.hero .tagline {
  margin: 0 auto 1.5rem;
  max-width: 28rem;
  color: var(--muted);
  font-size: 1.05rem;
}

.btn-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  justify-content: center;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.65rem 1.25rem;
  border-radius: 999px;
  font-weight: 600;
  font-size: 0.9rem;
  border: none;
  cursor: pointer;
  text-decoration: none;
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}

.btn:hover {
  text-decoration: none;
  transform: translateY(-1px);
}

.btn-primary {
  background: var(--accent);
  color: #fff;
  box-shadow: 0 4px 20px rgba(255, 107, 74, 0.35);
}

.btn-secondary {
  background: var(--surface);
  color: var(--text);
  border: 1px solid var(--border);
}

.features {
  display: grid;
  gap: 1rem;
  margin-top: 2.5rem;
}

@media (min-width: 640px) {
  .features {
    grid-template-columns: repeat(3, 1fr);
  }
}

.feature-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem;
}

.feature-card h3 {
  margin: 0 0 0.5rem;
  font-size: 1rem;
}

.feature-card p {
  margin: 0;
  font-size: 0.875rem;
  color: var(--muted);
}

.legal-back {
  display: inline-block;
  margin: 0 0 1.25rem;
  font-size: 0.875rem;
  color: var(--muted);
}

.legal-back:hover {
  color: var(--text);
}

.legal-notice {
  margin: 0 0 1.25rem;
  padding: 0.85rem 1rem;
  font-size: 0.9rem;
  line-height: 1.65;
  background: var(--accent-soft);
  border-left: 3px solid var(--accent);
  border-radius: 0 var(--radius) var(--radius) 0;
  color: var(--text);
}

.legal-notice strong {
  font-weight: 700;
}

.legal-page h1 {
  margin: 0 0 0.5rem;
  font-size: 1.5rem;
}

.legal-page .updated {
  margin: 0 0 2rem;
  font-size: 0.8rem;
  color: var(--muted);
}

.legal-page section {
  margin-bottom: 1.75rem;
}

.legal-page h2 {
  margin: 0 0 0.5rem;
  font-size: 1.05rem;
  font-weight: 700;
}

.legal-page h3 {
  margin: 1rem 0 0.4rem;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text);
}

.legal-page p,
.legal-page ul {
  margin: 0 0 0.75rem;
  font-size: 0.9rem;
  color: var(--muted);
}

.legal-page ul {
  padding-left: 1.25rem;
}

.site-footer {
  margin-top: auto;
  padding: 1.5rem 1.25rem;
  border-top: 1px solid var(--border);
  text-align: center;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem 1.25rem;
  justify-content: center;
  margin-bottom: 0.75rem;
}

.footer-links a {
  font-size: 0.85rem;
  color: var(--muted);
}

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

.site-footer .copy {
  margin: 0;
  font-size: 0.75rem;
  color: var(--muted);
  opacity: 0.8;
}

.layout {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}