/* Base */
:root {
  --bg: #ffffff;
  --text: #1d1d1f;
  --muted: #555;
  --primary: #1a73e8; /* Google系のニュアンス */
  --secondary: #0b57d0;
  --accent: #34a853; /* 緑のアクセント */
  --border: #e5e7eb;
  --surface: #f8fafc;
  --radius: 12px;
  --radius-sm: 8px;
  --shadow-sm: 0 2px 10px rgba(0,0,0,0.06);
  --shadow-md: 0 6px 24px rgba(0,0,0,0.08);
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  font-family: system-ui, -apple-system, "Hiragino Kaku Gothic ProN", "Noto Sans JP", "Yu Gothic", sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
}

/* Layout */
.container {
  width: 100%;
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 20px;
}

/* Header */
.site-header {
  border-bottom: 1px solid var(--border);
  background: #fff;
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 72px;
}
.brand-logo {
  height: 40px;
  width: auto;
}
.site-nav ul { display: flex; gap: 20px; list-style: none; padding: 0; margin: 0; }
.site-nav a {
  color: var(--text);
  text-decoration: none;
  padding: 10px 8px;
  border-radius: 6px;
}
.site-nav a:hover { background: var(--surface); }

/* Hero */
.hero {
  background: linear-gradient(180deg, #ffffff 0%, #f5f7fb 100%);
  border-bottom: 1px solid var(--border);
}
.hero-inner {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 32px;
  padding: 48px 0 56px;
}
.hero-copy h1 {
  font-size: clamp(28px, 4vw, 40px);
  line-height: 1.25;
  margin: 0 0 16px;
}
.hero-sub {
  color: var(--muted);
  font-size: 18px;
  margin: 0 0 24px;
}
.hero-cta { display: flex; gap: 12px; flex-wrap: wrap; }
.hero-media img {
  width: 100%;
  height: auto;
  border-radius: var(--radius);
  box-shadow: var(--shadow-md);
  object-fit: cover;
}

/* Buttons */
.btn {
  display: inline-block;
  padding: 12px 18px;
  border-radius: 10px;
  text-decoration: none;
  font-weight: 600;
  transition: transform 0.05s ease, box-shadow 0.2s ease, background 0.2s ease, color 0.2s ease;
  box-shadow: var(--shadow-sm);
}
.btn:hover { transform: translateY(-1px); }
.btn-primary {
  background: var(--primary);
  color: #fff;
}
.btn-primary:hover { background: #155ec2; }
.btn-secondary {
  background: #eef3fd;
  color: var(--secondary);
}
.btn-secondary:hover { background: #e3ecff; }

/* Intro */
.intro { padding: 56px 0; }
.intro-grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 28px;
  align-items: center;
}
.intro-image img {
  width: 100%;
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
}

/* Sections */
.section { padding: 56px 0; }
.section-alt { padding: 56px 0; background: var(--surface); }
.section h2 {
  font-size: 28px;
  margin: 0 0 20px;
}

/* Cards */
.card-list {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  list-style: none;
  margin: 0;
  padding: 0;
}
.card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  box-shadow: var(--shadow-sm);
}
.card h3 {
  font-size: 18px;
  margin: 0 0 8px;
}
.card p {
  margin: 0;
  color: var(--muted);
}

/* Use cases */
.usecases-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 18px;
}
.usecase {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  box-shadow: var(--shadow-sm);
}
.usecase h3 {
  font-size: 18px;
  margin: 0 0 8px;
}
.usecase p { margin: 0; color: var(--muted); }

/* FAQ */
.faq-item {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px 20px;
  margin-bottom: 12px;
  box-shadow: var(--shadow-sm);
}
.faq-item summary {
  cursor: pointer;
  font-weight: 600;
}
.faq-item p {
  margin: 10px 0 0;
  color: var(--muted);
}

/* Contact */
.contact {
  background: linear-gradient(180deg, #f5f7fb 0%, #ffffff 100%);
  border-top: 1px solid var(--border);
}
.contact-inner {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 24px;
  padding: 40px 0;
}
.contact-list {
  list-style: none;
  padding: 0;
  margin: 16px 0 0;
}
.contact-list li { margin-bottom: 8px; }

/* Footer */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 24px 0;
  background: #fff;
}
.footer-brand img {
  height: 28px;
  width: auto;
}
.footer-copy {
  color: var(--muted);
  margin: 8px 0 0;
}

/* Responsive */
@media (max-width: 960px) {
  .hero-inner,
  .intro-grid,
  .usecases-grid,
  .contact-inner {
    grid-template-columns: 1fr;
  }
  .card-list {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 640px) {
  .card-list {
    grid-template-columns: 1fr;
  }
  .site-nav ul { gap: 8px; }
  .hero-copy h1 { font-size: 28px; }
  .hero-sub { font-size: 16px; }
}