:root {
  --primary-color: #1f6feb;
  --secondary-color: #0b3d6d;
  --accent-color: #ffb454;
  --background-color: #f2f5fb;
  --surface-color: #ffffff;
  --surface-muted: #eef2fa;
  --text-dark: #1a2433;
  --text-muted: #4a5a72;
  --border-color: #d9e2f1;
  --shadow-soft: 0 20px 40px rgba(11, 61, 109, 0.18);
  --font-base: 'Helvetica Neue', Arial, 'Hiragino Kaku Gothic ProN', 'Hiragino Sans', Meiryo, sans-serif;
  --font-heading: 'Merriweather', 'Times New Roman', serif;
  --max-width: 1200px;
  --header-height: 72px;
  --transition: all 0.3s ease;
}

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

body {
  font-family: var(--font-base);
  background: var(--background-color);
  color: var(--text-dark);
  line-height: 1.75;
}

a {
  color: var(--primary-color);
  text-decoration: none;
  transition: color 0.2s ease;
}

a:hover {
  color: var(--accent-color);
}

img {
  max-width: 100%;
  display: block;
  border-radius: 16px;
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 28px;
}

.header {
  position: sticky;
  top: 0;
  z-index: 999;
  backdrop-filter: blur(10px);
  background: rgba(242, 245, 251, 0.94);
  border-bottom: 1px solid rgba(217, 226, 241, 0.8);
  transition: box-shadow var(--transition), background var(--transition);
}

.header.scrolled {
  background: rgba(242, 245, 251, 0.98);
  box-shadow: 0 12px 30px rgba(11, 61, 109, 0.15);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-height);
}

.logo a {
  font-family: var(--font-heading);
  font-size: 1.6rem;
  font-weight: 600;
  color: var(--secondary-color);
  letter-spacing: 0.04em;
}

.nav-menu {
  display: flex;
  list-style: none;
  gap: 1.1rem;
  align-items: center;
  flex-wrap: wrap;
  justify-content: flex-end;
  max-width: 880px;
}

.nav-item a {
  padding: 0.45rem 1rem;
  border-radius: 999px;
  font-size: 0.94rem;
  font-weight: 500;
  color: var(--secondary-color);
  background: rgba(255, 255, 255, 0.7);
  border: 1px solid transparent;
  transition: var(--transition);
  white-space: nowrap;
}

.nav-item a:hover,
.nav-item a.active {
  color: #fff;
  background: linear-gradient(125deg, #1f6feb, #154a99);
  border-color: rgba(21, 74, 153, 0.25);
}

.hamburger {
  display: none;
  flex-direction: column;
  gap: 6px;
  cursor: pointer;
  padding: 0.35rem;
  border-radius: 10px;
}

.hamburger span {
  width: 28px;
  height: 3px;
  background-color: var(--secondary-color);
  border-radius: 3px;
  transition: var(--transition);
}

.hero {
  position: relative;
  margin-top: 16px;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 2.4rem;
  align-items: center;
  padding: 3.5rem 0;
}

.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at top left, rgba(31, 111, 235, 0.22), rgba(15, 45, 84, 0));
  pointer-events: none;
}

.hero img {
  width: 100%;
  box-shadow: var(--shadow-soft);
  border-radius: 22px;
}

.hero-content {
  position: relative;
  z-index: 1;
  padding: 0 20px;
}

.hero-content h1 {
  font-family: var(--font-heading);
  font-size: clamp(2.4rem, 3.4vw, 3.1rem);
  color: var(--secondary-color);
  margin-bottom: 1.1rem;
  line-height: 1.25;
  text-shadow: 0 2px 8px rgba(0, 0, 0, 0.3), 0 4px 16px rgba(0, 0, 0, 0.2);
}

.hero-content p {
  font-size: 1.05rem;
  color: var(--text-muted);
  max-width: 540px;
  text-shadow: 0 1px 4px rgba(0, 0, 0, 0.25), 0 2px 8px rgba(0, 0, 0, 0.15);
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.3rem 0.85rem;
  border-radius: 999px;
  background: rgba(31, 111, 235, 0.15);
  color: var(--secondary-color);
  font-weight: 600;
  font-size: 0.78rem;
  letter-spacing: 0.05em;
  margin-bottom: 1rem;
  text-shadow: 0 1px 3px rgba(0, 0, 0, 0.2);
}

.section {
  padding: 3.4rem 0;
}

.section-title {
  font-family: var(--font-heading);
  font-size: 2rem;
  color: var(--secondary-color);
  margin-bottom: 1.8rem;
}

.lead-paragraph {
  font-size: 1.05rem;
  color: var(--text-muted);
  margin-bottom: 2rem;
}

.highlight-box {
  background: linear-gradient(140deg, rgba(31, 111, 235, 0.12), rgba(255, 180, 84, 0.14));
  border-radius: 22px;
  border: 1px solid rgba(31, 111, 235, 0.18);
  padding: 1.6rem;
  display: grid;
  gap: 0.8rem;
}

.highlight-box h3 {
  font-family: var(--font-heading);
  color: var(--secondary-color);
}

.news-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1.6rem;
}

.news-card {
  background: var(--surface-muted);
  border-radius: 20px;
  border: 1px solid rgba(217, 226, 241, 0.75);
  padding: 1.4rem;
  display: grid;
  gap: 0.7rem;
}

.news-meta {
  display: flex;
  justify-content: space-between;
  font-size: 0.78rem;
  color: var(--text-muted);
}

.news-card h4 {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--secondary-color);
}

.grid-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1.8rem;
}

.card {
  background: var(--surface-color);
  border-radius: 20px;
  border: 1px solid rgba(217, 226, 241, 0.9);
  padding: 1.8rem;
  display: grid;
  gap: 1rem;
  position: relative;
  transition: transform 0.3s ease, box-shadow 0.3s ease;
  overflow: hidden;
}

.card::after {
  content: '';
  position: absolute;
  inset: auto -10% -30% auto;
  width: 140px;
  height: 140px;
  background: radial-gradient(circle, rgba(255, 180, 84, 0.4), transparent 70%);
  opacity: 0;
  transition: opacity 0.3s ease;
}

.card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-soft);
}

.card:hover::after {
  opacity: 1;
}

.card .tag {
  display: inline-flex;
  padding: 0.3rem 0.75rem;
  border-radius: 999px;
  background: rgba(255, 180, 84, 0.18);
  color: var(--secondary-color);
  font-size: 0.75rem;
  font-weight: 600;
}

.card h3 {
  font-family: var(--font-heading);
  font-size: 1.25rem;
  color: var(--secondary-color);
}

.card p {
  color: var(--text-muted);
}

.card a {
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
}

.card a::after {
  content: '→';
  font-size: 0.9rem;
}

.data-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1.6rem;
}

.data-card {
  background: var(--surface-color);
  border-radius: 18px;
  padding: 1.8rem;
  border: 1px solid rgba(31, 111, 235, 0.15);
  box-shadow: 0 10px 24px rgba(15, 45, 84, 0.08);
  display: grid;
  gap: 0.6rem;
}

.data-card h4 {
  font-size: 0.95rem;
  letter-spacing: 0.06em;
  color: var(--text-muted);
  text-transform: uppercase;
}

.data-card .data-value {
  font-family: var(--font-heading);
  font-size: 2.4rem;
  color: var(--secondary-color);
}

.page-wrapper {
  padding: 3.2rem 0 4rem;
}

.main-layout {
  display: grid;
  grid-template-columns: minmax(0, 720px) minmax(0, 300px);
  gap: 2.4rem;
  align-items: start;
}

.article {
  background: var(--surface-color);
  border-radius: 24px;
  border: 1px solid rgba(217, 226, 241, 0.8);
  box-shadow: var(--shadow-soft);
  padding: 2.4rem;
  display: grid;
  gap: 2rem;
}

.article header {
  border-bottom: 1px solid rgba(217, 226, 241, 0.7);
  padding-bottom: 1.3rem;
}

.article-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 1.1rem;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.article h2 {
  font-family: var(--font-heading);
  font-size: 1.75rem;
  color: var(--secondary-color);
  margin-bottom: 1rem;
}

.article p {
  color: var(--text-dark);
}

.article ul {
  padding-left: 1.4rem;
  display: grid;
  gap: 0.4rem;
}

blockquote {
  border-left: 4px solid var(--accent-color);
  padding-left: 1rem;
  color: var(--text-muted);
  font-style: italic;
  margin: 1.6rem 0;
}

.table-scroll {
  overflow-x: auto;
  border-radius: 16px;
  border: 1px solid rgba(217, 226, 241, 0.8);
  margin: 1.6rem 0;
}

.table-scroll table {
  width: 100%;
  border-collapse: collapse;
  min-width: 520px;
}

.table-scroll th,
.table-scroll td {
  padding: 0.85rem 1rem;
  border-bottom: 1px solid rgba(217, 226, 241, 0.7);
  text-align: left;
  font-size: 0.92rem;
}

.sidebar {
  display: grid;
  gap: 1.6rem;
  position: sticky;
  top: calc(var(--header-height) + 20px);
}

.toc,
.sidebar-card {
  background: var(--surface-muted);
  border-radius: 18px;
  border: 1px solid rgba(217, 226, 241, 0.8);
  padding: 1.6rem;
  display: grid;
  gap: 0.9rem;
}

.toc ul {
  list-style: none;
  display: grid;
  gap: 0.6rem;
}

.toc a {
  color: var(--secondary-color);
  font-weight: 500;
}

.cta-banner {
  background: linear-gradient(125deg, #1f6feb, #0f2d54);
  border-radius: 24px;
  padding: 2rem;
  color: #fff;
  display: grid;
  gap: 1rem;
  box-shadow: 0 26px 44px rgba(11, 61, 109, 0.28);
}

.cta-button {
  justify-self: start;
  padding: 0.75rem 1.6rem;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.92);
  color: var(--secondary-color);
  font-weight: 600;
  transition: var(--transition);
}

.cta-button:hover {
  transform: translateY(-3px);
  box-shadow: 0 14px 28px rgba(11, 61, 109, 0.2);
}

.footer {
  background: linear-gradient(130deg, rgba(15, 45, 84, 0.95), rgba(31, 111, 235, 0.92));
  color: #f5f8ff;
  padding: 3.5rem 0;
  margin-top: 4rem;
}

.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 28px;
  display: grid;
  gap: 1.6rem;
}

.footer-inner h4 {
  font-family: var(--font-heading);
  letter-spacing: 0.08em;
}

.footer-inner ul {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
}

.footer-inner a {
  color: #f5f8ff;
  opacity: 0.85;
}

.footer-inner a:hover {
  opacity: 1;
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  font-size: 0.85rem;
  opacity: 0.8;
}


.cta-note {
  font-weight: 600;
  color: rgba(255, 255, 255, 0.9);
  margin: 0;
}
@media (max-width: 992px) {
  .main-layout {
    grid-template-columns: 1fr;
    display: flex;
    flex-direction: column;
  }

  .sidebar {
    position: static;
    order: -1;
  }

  .article {
    order: 0;
  }
}

@media (max-width: 860px) {
  .nav-menu {
    display: none;
    flex-direction: column;
    position: absolute;
    top: calc(var(--header-height) + 12px);
    right: 28px;
    left: 28px;
    background: rgba(242, 245, 251, 0.98);
    border-radius: 18px;
    border: 1px solid rgba(217, 226, 241, 0.9);
    padding: 1.4rem;
    box-shadow: var(--shadow-soft);
  }

  .nav-menu.active {
    display: flex;
  }

  .hamburger {
    display: flex;
  }

  .hamburger.active span:nth-child(1) {
    transform: translateY(9px) rotate(45deg);
  }

  .hamburger.active span:nth-child(2) {
    opacity: 0;
  }

  .hamburger.active span:nth-child(3) {
    transform: translateY(-9px) rotate(-45deg);
  }
}

@media (max-width: 600px) {
  .section {
    padding: 2.8rem 0;
  }

  .article,
  .sidebar-card,
  .toc {
    padding: 1.6rem;
  }

  .hero-content h1 {
    font-size: 2.2rem;
  }

  .cta-banner {
    text-align: center;
  }

  .cta-button {
    justify-self: center;
  }
}