:root {
  --bg: #f8fafc;
  --paper: #ffffff;
  --ink: #0f172a;
  --muted: #64748b;
  --blue-900: #0a2a66;
  --blue-800: #0f3a86;
  --blue-700: #1a55b8;
  --blue-600: #2a6fe8;
  --blue-200: #cfe1ff;
  --line: rgba(15, 23, 42, 0.08);
  --shadow: 0 1px 3px rgba(15, 23, 42, 0.08), 0 12px 24px rgba(10, 42, 102, 0.08);
  --radius: 16px;
  --radius-sm: 12px;
}
* {
  box-sizing: border-box;
}
html,
body {
  height: 100%;
}
body {
  margin: 0;
  font-family: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, "Hiragino Kaku Gothic ProN", "Noto Sans JP", "Yu Gothic", "Meiryo", sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.7;
  letter-spacing: 0.01em;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}
a {
  color: var(--blue-700);
  text-decoration: none;
  transition: color 0.2s ease;
}
a:hover {
  color: var(--blue-600);
}
/* レイアウト / 最大幅640px */
.wrap {
  max-width: 640px;
  margin: 0 auto;
  padding: 32px 20px 40px;
}
/* ヘッダー */
header {
  position: relative;
  border-radius: var(--radius);
  overflow: hidden;
  background: linear-gradient(135deg, var(--blue-800) 0%, var(--blue-600) 100%);
  box-shadow: var(--shadow);
}
.hero {
  display: block;
  width: 100%;
  height: auto;
  max-height: 240px;
  object-fit: cover;
  background: linear-gradient(135deg, rgba(207, 225, 255, 0.15), rgba(10, 42, 102, 0.05));
}
.head-inner {
  padding: 24px 28px 26px;
}
header h1 {
  margin: 0;
  font-size: clamp(24px, 4vw, 32px);
  line-height: 1.25;
  letter-spacing: -0.01em;
  font-weight: 700;
}
.site-title {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: #fff;
  text-decoration: none;
}
.site-title:hover {
  text-decoration: none;
}
.site-title::before {
  content: "";
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: #ffffff;
  box-shadow: 0 0 0 3px rgba(255, 255, 255, 0.2);
  flex: 0 0 auto;
}
.tagline {
  margin: 12px 0 0;
  color: rgba(255, 255, 255, 0.9);
  font-size: 14px;
  line-height: 1.6;
  font-weight: 400;
}
/* メインコンテンツ */
main {
  margin-top: 24px;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}
.content {
  padding: 32px 28px 28px;
}
.content p {
  margin: 0 0 20px;
  line-height: 1.8;
}
.content img {
  display: block;
  margin: 28px auto;
  max-width: 100%;
  height: auto;
  border-radius: var(--radius-sm);
  box-shadow: 0 4px 12px rgba(15, 23, 42, 0.1);
}
/* 見出し */
.content h2,
.content h3,
.content h4 {
  margin: 40px 0 20px;
  line-height: 1.4;
  letter-spacing: -0.01em;
  color: var(--ink);
  font-weight: 700;
}
.content h2 {
  font-size: 22px;
  padding-bottom: 12px;
  border-bottom: 2px solid var(--line);
  position: relative;
}
.content h2::before {
  content: "";
  position: absolute;
  left: 0;
  bottom: -2px;
  width: 48px;
  height: 2px;
  background: var(--blue-600);
  border-radius: 2px;
}
.content h3 {
  font-size: 18px;
  display: flex;
  align-items: center;
  gap: 10px;
}
.content h3::before {
  content: "";
  width: 4px;
  height: 20px;
  background: var(--blue-600);
  border-radius: 2px;
  flex-shrink: 0;
}
.content h4 {
  font-size: 16px;
  color: var(--muted);
}
/* リスト */
.content ul,
.content ol {
  margin: 20px 0;
  padding-left: 1.5em;
}
.content li {
  margin: 10px 0;
  line-height: 1.8;
}
.content ul li::marker {
  color: var(--blue-600);
}
.content ol li::marker {
  color: var(--blue-700);
  font-weight: 600;
}
/* 引用 */
.content blockquote {
  margin: 24px 0;
  padding: 20px 24px;
  border-radius: var(--radius-sm);
  border-left: 4px solid var(--blue-600);
  background: #f8fafc;
  color: var(--muted);
}
.content blockquote p {
  margin-bottom: 0;
}
/* テーブル */
.content table {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0;
  margin: 24px 0;
  border-radius: var(--radius-sm);
  overflow: hidden;
  border: 1px solid var(--line);
  font-size: 14px;
}
.content thead th {
  text-align: left;
  font-weight: 600;
  font-size: 13px;
  color: var(--ink);
  background: #f8fafc;
  padding: 14px 16px;
  border-bottom: 1px solid var(--line);
}
.content tbody td {
  padding: 14px 16px;
  border-bottom: 1px solid var(--line);
  vertical-align: top;
}
.content tbody tr:hover td {
  background: #fafbfc;
}
.content tbody tr:last-child td {
  border-bottom: 0;
}
/* 区切り線 */
.divider {
  margin: 32px 0;
  height: 1px;
  background: var(--line);
}
/* フッター */
footer {
  margin-top: 32px;
  padding: 0 0 40px;
}
.foot-box {
  max-width: 640px;
  margin: 0 auto;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}
.foot-nav {
  padding: 24px 24px 16px;
}
.foot-nav ul {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}
.foot-nav a {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 16px;
  border-radius: 8px;
  border: 1px solid var(--line);
  background: var(--paper);
  color: var(--ink);
  font-size: 14px;
  line-height: 1.4;
  text-decoration: none;
  transition: all 0.2s ease;
}
.foot-nav a::before {
  content: "";
  color: var(--blue-600);
  font-weight: 600;
  font-size: 18px;
}
.foot-nav a:hover {
  border-color: var(--blue-600);
  background: #f8fafc;
  transform: translateX(2px);
}
.foot-meta {
  padding: 20px 24px 24px;
  border-top: 1px solid var(--line);
  display: grid;
  gap: 12px;
}
.foot-meta .links {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  font-size: 14px;
  color: var(--muted);
}
.foot-meta .links a {
  color: var(--blue-700);
  text-decoration: none;
  transition: color 0.2s ease;
}
.foot-meta .links a:hover {
  color: var(--blue-600);
  text-decoration: underline;
}
.copyright {
  font-size: 13px;
  color: var(--muted);
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  align-items: center;
}
.copyright .sep {
  opacity: 0.5;
}
/* リンクカード */
.link-card {
  margin: 24px 0;
}
.link-card a {
  display: block;
  text-decoration: none;
  color: inherit;
}
.link-card-inner {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 20px;
  border-radius: var(--radius-sm);
  background: var(--paper);
  border: 1px solid var(--line);
  box-shadow: 0 1px 3px rgba(15, 23, 42, 0.08);
  transition: all 0.2s ease;
}
.link-card a:hover .link-card-inner {
  border-color: var(--blue-600);
  box-shadow: 0 4px 12px rgba(26, 85, 184, 0.12);
  transform: translateY(-2px);
}
.link-card-text {
  flex: 1 1 auto;
}
.link-card-eyebrow {
  display: inline-block;
  margin-bottom: 8px;
  padding: 4px 10px;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.02em;
  color: var(--blue-700);
  border-radius: 6px;
  background: rgba(207, 225, 255, 0.5);
}
.link-card-text h3 {
  margin: 0 0 8px;
  font-size: 16px;
  font-weight: 600;
  line-height: 1.4;
}
.link-card-text p {
  margin: 0;
  font-size: 14px;
  line-height: 1.6;
  color: var(--muted);
}
.link-card-arrow {
  flex: 0 0 auto;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  display: grid;
  place-items: center;
  background: var(--blue-600);
  transition: transform 0.2s ease;
}
.link-card a:hover .link-card-arrow {
  transform: translateX(4px);
}
.link-card-arrow::before {
  content: "\2192";
  color: #ffffff;
  font-size: 16px;
  font-weight: 600;
}
/* スマホ最適化 */
@media (max-width: 640px) {
  .wrap {
    padding: 24px 16px 32px;
  }
  .head-inner {
    padding: 20px 20px 22px;
  }
  .content {
    padding: 24px 20px 20px;
  }
  .content h2 {
    font-size: 20px;
    margin: 32px 0 16px;
  }
  .content h3 {
    font-size: 17px;
  }
  .foot-nav {
    padding: 20px 16px 12px;
  }
  .foot-nav a {
    padding: 9px 14px;
    font-size: 13px;
  }
  .foot-meta {
    padding: 16px 16px 20px;
  }
  .link-card-inner {
    padding: 16px;
    gap: 14px;
  }
  .link-card-text h3 {
    font-size: 15px;
  }
  .link-card-text p {
    font-size: 13px;
  }
}
@media (max-width: 380px) {
  .wrap {
    padding-left: 12px;
    padding-right: 12px;
  }
  .content {
    padding-left: 16px;
    padding-right: 16px;
  }
  .head-inner {
    padding-left: 16px;
    padding-right: 16px;
  }
  .foot-nav a {
    padding: 8px 12px;
  }
}