/* =========================================
   fuu LP 共通スタイル
   準拠: docs/04-design-system.md
   ========================================= */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700;800&family=Noto+Sans+JP:wght@400;500;600;700;800&display=swap');

:root {
  --bg-primary: #FFFFFF;
  --bg-secondary: #FAFAFA;
  --surface-gray: #F1F2F4;
  --border-light: #E4E4E7;
  --brand-blue: #0084FF;
  --brand-blue-dark: #006FDB;
  --brand-blue-subtle: #E3F2FF;
  --ai-accent: #8B5CF6;
  --ai-subtle: #F3E8FF;
  --text-primary: #18181B;
  --text-secondary: #71717A;
  --text-tertiary: #A1A1AA;
  --text-on-brand: #FFFFFF;
}

* { -webkit-font-smoothing: antialiased; box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  font-family: 'Noto Sans JP', 'Inter', system-ui, sans-serif;
  color: var(--text-primary);
  background: var(--bg-primary);
  margin: 0;
  line-height: 1.6;
}

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

/* =========================================
   レイアウト
   ========================================= */

.container {
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 24px;
}

.container-narrow {
  max-width: 760px;
  margin: 0 auto;
  padding: 0 24px;
}

section { padding: 80px 0; }
@media (max-width: 768px) { section { padding: 56px 0; } }

/* =========================================
   ナビ
   ========================================= */

.nav {
  position: sticky;
  top: 0;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-light);
  z-index: 50;
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 0;
}

.brand {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 700;
  font-size: 20px;
  letter-spacing: -0.5px;
}

.brand-mark {
  width: 28px;
  height: 28px;
  border-radius: 8px;
  background: var(--brand-blue);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: white;
}

.nav-links { display: flex; gap: 32px; align-items: center; }
.nav-links a { font-size: 14px; color: var(--text-secondary); }
.nav-links a:hover { color: var(--text-primary); }

@media (max-width: 640px) {
  .nav-links { display: none; }
}

/* =========================================
   ボタン
   ========================================= */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 0 24px;
  height: 48px;
  border-radius: 24px;
  font-weight: 600;
  font-size: 15px;
  font-family: inherit;
  border: none;
  cursor: pointer;
  transition: all 200ms cubic-bezier(0.16, 1, 0.3, 1);
  text-decoration: none;
}

.btn-primary {
  background: var(--brand-blue);
  color: white;
}
.btn-primary:hover {
  background: var(--brand-blue-dark);
  transform: translateY(-1px);
  box-shadow: 0 8px 20px rgba(0, 132, 255, 0.3);
}

.btn-outline {
  background: white;
  color: var(--text-primary);
  border: 1px solid var(--border-light);
}
.btn-outline:hover {
  border-color: var(--brand-blue);
  color: var(--brand-blue);
}

.btn-lg { height: 56px; padding: 0 32px; font-size: 16px; border-radius: 28px; }

/* =========================================
   タイポ
   ========================================= */

h1, h2, h3, h4 {
  letter-spacing: -0.5px;
  line-height: 1.25;
  margin: 0;
}

.eyebrow {
  display: inline-block;
  padding: 4px 12px;
  background: var(--brand-blue-subtle);
  color: var(--brand-blue);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.5px;
  border-radius: 12px;
  margin-bottom: 20px;
}

.section-title {
  font-size: 40px;
  font-weight: 700;
  margin-bottom: 16px;
  letter-spacing: -1px;
}
@media (max-width: 640px) { .section-title { font-size: 28px; } }

.section-lead {
  font-size: 17px;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 48px;
}

/* =========================================
   フッター
   ========================================= */

.footer {
  background: #FAFAFA;
  border-top: 1px solid var(--border-light);
  padding: 56px 0 40px;
  font-size: 14px;
}

.footer-cols {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 32px;
  margin-bottom: 40px;
}
@media (max-width: 768px) {
  .footer-cols { grid-template-columns: 1fr 1fr; }
}

.footer-col h4 { font-size: 13px; font-weight: 600; color: var(--text-primary); margin-bottom: 12px; }
.footer-col a { display: block; color: var(--text-secondary); padding: 4px 0; }
.footer-col a:hover { color: var(--brand-blue); }
.footer-meta { font-size: 13px; color: var(--text-tertiary); }

.footer-meta-grid {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 24px;
  border-top: 1px solid var(--border-light);
}
@media (max-width: 640px) {
  .footer-meta-grid { flex-direction: column; gap: 12px; }
}