:root {
  --color-background: #f5f7fb;
  --color-surface: #ffffff;
  --color-primary: #1747a3;
  --color-primary-soft: #e3ecff;
  --color-accent: #ec6a37;
  --color-text: #1a1d23;
  --color-text-muted: #5b6470;
  --color-border: #d6dce8;
  --shadow-soft: 0 12px 32px rgba(19, 35, 78, 0.08);
  --radius-base: 16px;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: 'Noto Sans JP', 'Hiragino Sans', 'Yu Gothic', 'Meiryo', sans-serif;
  font-size: 16px;
  line-height: 1.75;
  color: var(--color-text);
  background: var(--color-background);
}

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

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

.skip-link {
  position: absolute;
  left: -999px;
  top: 10px;
  background: var(--color-primary);
  color: #fff;
  padding: 0.5rem 1rem;
  border-radius: 999px;
  z-index: 1001;
}

.skip-link:focus {
  left: 16px;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: linear-gradient(135deg, #0f2d68 0%, #143d8f 60%, #1c4eb4 100%);
  box-shadow: 0 8px 24px rgba(12, 23, 55, 0.18);
}

.header-inner {
  max-width: 1180px;
  margin: 0 auto;
  padding: 1rem 1.5rem;
  display: flex;
  align-items: center;
  gap: 1.5rem;
  flex-wrap: wrap;
}

.brand {
  font-size: 1.3rem;
  font-weight: 700;
  color: #fff;
  letter-spacing: 0.04em;
}

.menu-toggle {
  display: none;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 0.75rem;
  border: 1px solid rgba(255, 255, 255, 0.4);
  border-radius: 999px;
  background: transparent;
  color: #fff;
  cursor: pointer;
}

.menu-icon {
  display: inline-block;
  width: 20px;
  height: 2px;
  background: currentColor;
  position: relative;
}

.menu-icon::before,
.menu-icon::after {
  content: '';
  position: absolute;
  left: 0;
  width: 20px;
  height: 2px;
  background: currentColor;
  transition: transform 0.2s ease;
}

.menu-icon::before {
  top: -6px;
}

.menu-icon::after {
  top: 6px;
}

.menu-toggle[aria-expanded="true"] .menu-icon {
  background: transparent;
}

.menu-toggle[aria-expanded="true"] .menu-icon::before {
  transform: translateY(6px) rotate(45deg);
}

.menu-toggle[aria-expanded="true"] .menu-icon::after {
  transform: translateY(-6px) rotate(-45deg);
}

.site-nav {
  flex: 1 1 auto;
}

.site-nav ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  justify-content: flex-end;
}

.site-nav li {
  flex: 0 0 auto;
}

.nav-link {
  display: block;
  padding: 0.45rem 0.9rem;
  border-radius: 999px;
  color: #f3f6ff;
  font-size: 0.95rem;
  background: rgba(255, 255, 255, 0.12);
  transition: background 0.2s ease, transform 0.2s ease;
}

.nav-link:hover {
  background: rgba(255, 255, 255, 0.24);
  transform: translateY(-1px);
}

.nav-link.active {
  background: #fefefe;
  color: var(--color-primary);
  font-weight: 700;
}

.hero {
  position: relative;
  color: #fff;
  padding: 4.5rem 1.5rem 3rem;
  background-size: cover;
  background-position: center;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(120deg, rgba(10, 23, 60, 0.82) 0%, rgba(20, 51, 120, 0.7) 50%, rgba(8, 32, 82, 0.85) 100%);
  mix-blend-mode: multiply;
}

.hero-content {
  position: relative;
  max-width: 780px;
  margin: 0 auto;
  text-align: center;
}

.hero-kicker {
  font-size: 0.9rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: rgba(255, 255, 255, 0.7);
  margin-bottom: 0.75rem;
  text-shadow: 0 2px 8px rgba(0, 0, 0, 0.5), 0 4px 16px rgba(0, 0, 0, 0.3);
}

.hero-title {
  font-size: 2.4rem;
  line-height: 1.25;
  margin: 0 0 1.2rem;
  text-shadow: 0 2px 8px rgba(0, 0, 0, 0.6), 0 4px 16px rgba(0, 0, 0, 0.4);
}

.hero-text {
  font-size: 1.05rem;
  margin: 0 auto 1.25rem;
  color: rgba(255, 255, 255, 0.88);
  text-shadow: 0 2px 8px rgba(0, 0, 0, 0.5), 0 4px 16px rgba(0, 0, 0, 0.3);
}

.hero-actions {
  display: flex;
  justify-content: center;
  gap: 1rem;
  flex-wrap: wrap;
  position: relative;
  z-index: 1;
  margin-top: 1.5rem;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  padding: 0.65rem 1.3rem;
  border-radius: 999px;
  font-weight: 600;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
}

.button.primary {
  background: var(--color-accent);
  color: #fff;
  box-shadow: 0 12px 20px rgba(236, 106, 55, 0.28);
}

.button.primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 16px 28px rgba(236, 106, 55, 0.32);
}

.button.ghost {
  background: rgba(255, 255, 255, 0.1);
  color: #fff;
  border-color: rgba(255, 255, 255, 0.4);
}

.button.ghost:hover {
  background: rgba(255, 255, 255, 0.2);
}

.hero-figure {
  position: relative;
  max-width: 640px;
  margin: 2rem auto 0;
  padding: 0.75rem;
  border-radius: var(--radius-base);
  background: rgba(255, 255, 255, 0.08);
  backdrop-filter: blur(6px);
}

.hero-figure img {
  display: block;
  width: 100%;
  border-radius: calc(var(--radius-base) - 6px);
}

.hero-figure figcaption {
  margin-top: 0.5rem;
  font-size: 0.8rem;
  color: rgba(255, 255, 255, 0.75);
}

main {
  max-width: 1180px;
  margin: 0 auto;
  padding: 0 1.5rem 4rem;
}

.section {
  margin-top: 3.5rem;
  background: var(--color-surface);
  border-radius: var(--radius-base);
  padding: 2.5rem;
  box-shadow: var(--shadow-soft);
}

.section-header {
  margin-bottom: 1.5rem;
}

.section-kicker {
  font-size: 0.9rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin: 0 0 0.6rem;
}

.section h2 {
  margin: 0;
  font-size: 1.9rem;
  line-height: 1.3;
}

.section-body > p,
.section-body > ul,
.section-body > ol {
  margin-bottom: 1.2rem;
}

.news-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1.5rem;
}

.news-card {
  background: var(--color-surface);
  border-radius: var(--radius-base);
  padding: 1.25rem;
  border: 1px solid var(--color-border);
  box-shadow: var(--shadow-soft);
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.news-card h3 {
  margin: 0;
  font-size: 1.2rem;
}

.news-meta {
  font-size: 0.85rem;
  color: var(--color-text-muted);
  margin-top: auto;
}

.metrics-grid, .strategy-grid, .faq-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1.5rem;
}

.metric-card, .strategy-phase, .faq-item {
  background: var(--color-surface);
  border-radius: var(--radius-base);
  padding: 1.5rem;
  border: 1px solid var(--color-border);
  box-shadow: var(--shadow-soft);
}

.inline-ad {
  margin: 2.5rem auto;
  padding: 1.5rem;
  max-width: 360px;
  text-align: center;
  background: var(--color-surface);
  border: 1px dashed rgba(23, 71, 163, 0.35);
  border-radius: var(--radius-base);
  box-shadow: var(--shadow-soft);
}

.metric-card ul,
.strategy-phase p,
.faq-item p {
  margin-bottom: 0.8rem;
}

.insight-list {
  display: grid;
  gap: 1.25rem;
}

.insight-item {
  background: var(--color-surface);
  border-radius: var(--radius-base);
  padding: 1.5rem;
  border-left: 4px solid var(--color-primary);
  box-shadow: var(--shadow-soft);
}

.memo-content p {
  margin-bottom: 1rem;
}

.page-wrapper {
  margin-top: 3.5rem;
  display: grid;
  grid-template-columns: minmax(0, 2fr) minmax(0, 0.95fr);
  gap: 2.5rem;
}

/* デスクトップでは article を先、sidebar を後に表示 */
.article-content {
  order: 2;
}

.sidebar, .page-sidebar {
  order: 3;
}

.article-content section {
  background: var(--color-surface);
  border-radius: var(--radius-base);
  padding: 2.25rem;
  margin-bottom: 2rem;
  border: 1px solid var(--color-border);
  box-shadow: var(--shadow-soft);
}

.article-content h2 {
  margin-top: 0;
  font-size: 1.8rem;
}

.article-content h3 {
  margin-top: 1.75rem;
  font-size: 1.3rem;
  color: var(--color-primary);
}

.article-content p,
.article-content ul,
.article-content ol {
  margin-bottom: 1.1rem;
}

.article-content ul,
.article-content ol {
  padding-left: 1.3rem;
}

.sidebar {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.sidebar-section {
  background: var(--color-surface);
  border-radius: var(--radius-base);
  padding: 1.75rem;
  border: 1px solid var(--color-border);
  box-shadow: var(--shadow-soft);
}

.sidebar-section h2 {
  margin-top: 0;
  font-size: 1.2rem;
  border-bottom: 1px solid var(--color-border);
  padding-bottom: 0.6rem;
  margin-bottom: 1rem;
}

.sidebar-section ol,
.sidebar-section ul {
  margin: 0;
  padding-left: 1.2rem;
  display: grid;
  gap: 0.6rem;
  color: var(--color-text-muted);
}

.sidebar-section ul ul,
.sidebar-section ol ul {
  margin-top: 0.4rem;
  padding-left: 1.2rem;
}

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

.ad-slot {
  background: linear-gradient(135deg, rgba(23, 71, 163, 0.09), rgba(23, 71, 163, 0.02));
  border: 1px dashed rgba(23, 71, 163, 0.35);
  border-radius: calc(var(--radius-base) - 8px);
  padding: 1rem 1.25rem;
}

.site-footer {
  margin-top: 4rem;
  padding: 3rem 1.5rem 2.5rem;
  background: #0f1f3f;
  color: rgba(255, 255, 255, 0.82);
}

.footer-top {
  max-width: 1180px;
  margin: 0 auto 2rem;
  display: grid;
  gap: 2rem;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
}

.footer-brand a {
  color: #fff;
  font-weight: 700;
  font-size: 1.1rem;
}

.footer-links ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.5rem;
}

.footer-bottom {
  text-align: center;
  margin: 0;
  font-size: 0.85rem;
  color: rgba(255, 255, 255, 0.6);
}

@media (max-width: 960px) {
  .menu-toggle {
    display: inline-flex;
    margin-left: auto;
  }

  .site-nav {
    width: 100%;
  }

  .site-nav ul {
    display: none;
    width: 100%;
    flex-direction: column;
    background: rgba(10, 29, 78, 0.95);
    border-radius: var(--radius-base);
    padding: 1rem 1.2rem;
    margin-top: 0.75rem;
  }

  .site-nav.is-open ul {
    display: flex;
  }

  .nav-link {
    width: 100%;
  }

  .hero {
    padding: 3.5rem 1.2rem 2.5rem;
  }

  .page-wrapper {
    grid-template-columns: 1fr;
    display: flex;
    flex-direction: column;
  }

  /* モバイルでは sidebar を先、article を後に表示 */
  .sidebar, .page-sidebar {
    order: 1;
  }

  .article-content {
    order: 2;
  }

  .hero-title {
    font-size: 2rem;
  }
}

@media (max-width: 720px) {
  .section {
    padding: 2rem;
  }

  .article-content section {
    padding: 1.75rem;
  }

  .hero-figure {
    padding: 0.6rem;
  }

  .hero-text {
    font-size: 1rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
  }
}