body {
  margin: 0;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Yu Gothic", "YuGothic", sans-serif;
  line-height: 1.6;
  color: #222;
  background: #f7f7f7;
}

/* ヘッダー */
header {
  background: #0f172a;
  color: #fff;
  padding: 0.6rem 0;
}
.container {
  width: 100%;
  max-width: 960px;
  margin: 0 auto;
  padding: 0 1rem;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}

.brand {
  display: flex;
  align-items: center;
  font-weight: 700;
  font-size: 1.05rem;
}
.logo {
  height: 36px;
  width: auto;
  margin-right: 0.5rem;
}

nav ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
}
nav a {
  color: #e5e7eb;
  text-decoration: none;
  font-size: 0.95rem;
}
nav a:hover {
  text-decoration: underline;
}

/* ヒーロー（背景画像＋暗めオーバーレイ） */
.hero {
  position: relative;
  padding: 3rem 0 2.5rem;
  background: #0f172a url("pixta_30626190_S.jpg") center/cover no-repeat;
  color: #e5e7eb;
  overflow: hidden;
}
.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background: rgba(15, 23, 42, 0.7); /* 文字を読みやすくする透過レイヤー */
}
.hero .container {
  position: relative;
  z-index: 1;
}
.hero-inner {
  max-width: 40rem;
}
.hero h1 {
  margin: 0 0 0.75rem;
  font-size: clamp(1.7rem, 3vw, 2.1rem);
}
.hero p {
  margin: 0.2rem 0;
  font-size: 0.98rem;
}
.hero-small {
  opacity: 0.9;
  font-size: 0.9rem;
}

/* 画像Bセクション */
.image-section {
  background: #0f172a;
  padding: 0 0 2rem;
}
.image-section .container {
  padding-top: 0;
}
.hero-image {
  width: 100%;
  display: block;
  border-radius: 0.75rem;
  box-shadow: 0 4px 10px rgba(15, 23, 42, 0.35);
  object-fit: cover;
}

/* メイン部分 */
main {
  padding: 2rem 0 3rem;
}
section {
  margin-bottom: 2rem;
  background: #fff;
  padding: 1.5rem;
  border-radius: 0.75rem;
  box-shadow: 0 2px 4px rgba(15,23,42,0.06);
}
h2 {
  margin-top: 0;
  font-size: 1.2rem;
  border-left: 4px solid #0f172a;
  padding-left: 0.5rem;
}
h3 {
  margin-bottom: 0.3rem;
  font-size: 1.05rem;
}
ul {
  padding-left: 1.2rem;
  margin-top: 0.2rem;
}
.tagline {
  font-weight: 600;
  margin-bottom: 0.4rem;
}
.two-column {
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem;
}
.two-column > div {
  flex: 1 1 260px;
}

.badge {
  display: inline-block;
  padding: 0.15rem 0.45rem;
  border-radius: 999px;
  font-size: 0.78rem;
  background: #e5e7eb;
  color: #374151;
  margin-right: 0.3rem;
  margin-bottom: 0.3rem;
}
.muted {
  font-size: 0.9rem;
  color: #6b7280;
}
.small {
  font-size: 0.8rem;
}
.link-button {
  display: inline-block;
  padding: 0.5rem 0.9rem;
  border-radius: 999px;
  border: 1px solid #0f172a;
  font-size: 0.9rem;
  text-decoration: none;
  color: #0f172a;
  margin-top: 0.4rem;
}
.link-button:hover {
  background: #0f172a;
  color: #fff;
}

/* フッター（3カラム） */
footer {
  border-top: 1px solid #e5e7eb;
  padding: 2rem 0 2rem;
  font-size: 0.85rem;
  color: #6b7280;
  background: #f9fafb;
}
.footer-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 2rem;
}
.footer-column {
  flex: 1 1 220px;
}
.footer-column h4 {
  margin-top: 0;
  margin-bottom: 0.5rem;
  font-size: 0.95rem;
  color: #111827;
}
.footer-column ul {
  list-style: disc;
  padding-left: 1.1rem;
  margin: 0.2rem 0 0;
}
.footer-bottom {
  border-top: 1px solid #e5e7eb;
  margin-top: 1.5rem;
  padding-top: 0.8rem;
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.5rem;
}

/* レスポンシブ対応 */
@media (max-width: 600px) {
  .header-inner {
    flex-direction: column;
    align-items: flex-start;
  }
  nav ul {
    padding-top: 0.3rem;
  }
  .footer-grid {
    flex-direction: column;
  }
}