:root {
  color-scheme: light;
  font-family: "Helvetica Neue", "Hiragino Kaku Gothic ProN", "Noto Sans JP", sans-serif;
  line-height: 1.6;
  --bg: #ffffff;
  --text: #1a1a1a;
  --muted: #5d5d5d;
  --primary: #0057ff;
  --border: #e3e3e3;
  --accent: #f3f7ff;
}

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

body {
  background: var(--bg);
  color: var(--text);
}

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

a:hover,
a:focus {
  text-decoration: underline;
}

img {
  max-width: 100%;
  height: auto;
}

header {
  border-bottom: 1px solid var(--border);
  background: var(--bg);
  position: sticky;
  top: 0;
  z-index: 10;
}

.container {
  width: min(1100px, 92%);
  margin: 0 auto;
}

.header-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 20px 0;
  gap: 16px;
}

.site-logo {
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--text);
}

.nav-list {
  display: flex;
  list-style: none;
  gap: 20px;
  flex-wrap: wrap;
}

.nav-link {
  color: var(--text);
  padding-bottom: 4px;
  border-bottom: 2px solid transparent;
}

.nav-link.active {
  border-bottom: 2px solid var(--primary);
  color: var(--primary);
}

.hero {
  background: var(--accent);
  padding: 48px 0;
}

.hero h1 {
  font-size: clamp(2rem, 3vw, 2.8rem);
  margin-bottom: 12px;
}

.hero p {
  color: var(--muted);
  max-width: 640px;
}

.section {
  padding: 48px 0;
  border-bottom: 1px solid var(--border);
}

.section:last-of-type {
  border-bottom: none;
}

.section h2 {
  font-size: 1.6rem;
  margin-bottom: 16px;
}

.section p {
  margin-bottom: 16px;
  color: var(--muted);
}

.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 20px;
}

.card {
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 20px;
  background: #fff;
}

.card h3 {
  margin-bottom: 12px;
  font-size: 1.1rem;
}

.list {
  list-style: none;
  display: grid;
  gap: 8px;
}

.list li {
  padding-left: 16px;
  position: relative;
}

.list li::before {
  content: "•";
  position: absolute;
  left: 0;
  color: var(--primary);
}

.table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 16px;
}

.table th,
.table td {
  border: 1px solid var(--border);
  padding: 12px;
  text-align: left;
}

.table th {
  background: var(--accent);
}

.cta {
  background: var(--accent);
  border-radius: 12px;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.cta a {
  font-weight: 600;
}

footer {
  border-top: 1px solid var(--border);
  padding: 24px 0 40px;
  color: var(--muted);
  font-size: 0.9rem;
}

footer .footer-links {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 12px;
}

@media (max-width: 720px) {
  .header-inner {
    flex-direction: column;
    align-items: flex-start;
  }

  .nav-list {
    gap: 12px;
  }

  .hero {
    padding: 36px 0;
  }
}