:root {
  --primary: #0f172a;
  --secondary: #334155;
  --muted: #64748b;
  --accent: #d97706;
  --accent-dark: #b45309;
  --bg-light: #f8fafc;
  --white: #ffffff;
  --border: #e2e8f0;
  --good: #047857;
  --bad: #b91c1c;
  --font-main: "Noto Sans JP", sans-serif;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  color: var(--secondary);
  background: var(--white);
  font-family: var(--font-main);
  line-height: 1.8;
}

a {
  color: inherit;
  text-decoration: none;
}

img {
  max-width: 100%;
}

.container {
  width: min(1120px, calc(100% - 32px));
  margin: 0 auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  border-bottom: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.96);
  backdrop-filter: blur(10px);
}

.header-inner {
  min-height: 68px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.logo {
  color: var(--primary);
  font-size: 1.18rem;
  font-weight: 900;
  letter-spacing: 0;
}

.header-nav {
  display: flex;
  align-items: center;
  gap: 16px;
  color: var(--secondary);
  font-size: 0.9rem;
  font-weight: 700;
}

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

.header-nav a.btn:hover {
  color: white;
}

.btn {
  display: inline-flex;
  justify-content: center;
  align-items: center;
  background: linear-gradient(135deg, #f59e0b 0%, #ea580c 100%);
  color: white;
  font-weight: bold;
  font-size: 1.1rem;
  padding: 18px 40px;
  border-radius: 999px;
  box-shadow: 0 10px 20px rgba(234, 88, 12, 0.2);
  transform: translateY(0);
  white-space: nowrap;
  max-width: 100%;
  position: relative;
  overflow: hidden;
  background: linear-gradient(135deg, #f59e0b 0%, #ea580c 55%, #dc2626 100%);
  font-weight: 800;
  letter-spacing: 0.02em;
  border: 1px solid rgba(255,255,255,0.18);
  box-shadow: 0 14px 28px rgba(234, 88, 12, 0.28), inset 0 1px 0 rgba(255,255,255,0.25);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.btn:hover {
  color: white;
  transform: translateY(-4px);
  box-shadow: 0 18px 34px rgba(234, 88, 12, 0.34), inset 0 1px 0 rgba(255,255,255,0.25);
}

.btn:active {
  transform: translateY(-1px);
}

.btn::before {
  content: "";
  position: absolute;
  inset: 1px;
  border-radius: inherit;
  background: linear-gradient(180deg, rgba(255,255,255,0.22), rgba(255,255,255,0) 45%);
  pointer-events: none;
}

.btn::after {
  content: "→";
  margin-left: 10px;
  font-weight: 900;
  position: relative;
  z-index: 1;
}

.btn > span {
  position: relative;
  z-index: 1;
}

.btn-main {
  animation: cta-float 2.8s ease-in-out infinite;
}

.btn-header {
  margin-left: auto;
  flex-shrink: 0;
  margin-right: 2px;
  padding: 10px 24px;
  font-size: 0.9rem;
  box-shadow: 0 10px 22px rgba(234, 88, 12, 0.22);
}

.btn.subtle {
  background: #fff7ed;
  color: #9a3412;
  border: 1px solid #fed7aa;
  box-shadow: none;
}

@keyframes cta-float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-3px); }
}

.article-hero {
  padding: 64px 0 44px;
  background: linear-gradient(135deg, #0f172a 0%, #1f2937 100%);
  color: white;
}

.breadcrumb {
  margin: 0 0 22px;
  color: #cbd5e1;
  font-size: 0.86rem;
}

.breadcrumb a {
  color: white;
  text-decoration: underline;
  text-underline-offset: 4px;
}

.eyebrow {
  display: inline-block;
  margin-bottom: 14px;
  color: #fbbf24;
  font-size: 0.82rem;
  font-weight: 900;
  letter-spacing: 0;
}

h1 {
  max-width: 880px;
  margin: 0;
  color: white;
  font-size: clamp(2rem, 4.2vw, 3.3rem);
  line-height: 1.22;
  letter-spacing: 0;
}

.lead {
  max-width: 820px;
  margin: 22px 0 0;
  color: #e2e8f0;
  font-size: 1.08rem;
}

.page-nav {
  padding: 18px 0;
  border-bottom: 1px solid var(--border);
  background: var(--bg-light);
}

.page-nav-list {
  display: flex;
  gap: 10px;
  overflow-x: auto;
  padding-bottom: 2px;
}

.page-nav-list a {
  flex: 0 0 auto;
  padding: 9px 13px;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: white;
  color: var(--secondary);
  font-size: 0.86rem;
  font-weight: 800;
  white-space: nowrap;
}

.page-nav-list a[aria-current="page"] {
  border-color: #fbbf24;
  background: #fffbeb;
  color: #92400e;
}

.main-wrap {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 320px;
  gap: 42px;
  align-items: start;
  padding: 56px 0;
}

.article-body h2 {
  margin: 52px 0 18px;
  padding-bottom: 10px;
  border-bottom: 3px solid #f1f5f9;
  color: var(--primary);
  font-size: 1.62rem;
  line-height: 1.45;
}

.article-body h3 {
  margin: 32px 0 12px;
  color: var(--primary);
  font-size: 1.2rem;
  line-height: 1.5;
}

.article-body p {
  margin: 0 0 18px;
}

.article-visual {
  margin: 28px 0 34px;
  overflow: hidden;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: #f8fafc;
  box-shadow: 0 14px 30px rgba(15, 23, 42, 0.08);
}

.article-visual img {
  display: block;
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
}

.updated-note {
  margin: -10px 0 30px;
  color: var(--muted);
  font-size: 0.88rem;
  text-align: right;
}

.decision-box,
.source-box,
.seo-faq {
  margin: 34px 0;
}

.decision-box {
  padding: 24px;
  border: 1px solid #fed7aa;
  border-radius: 8px;
  background: #fff7ed;
}

.decision-box h2,
.source-box h2,
.seo-faq h2 {
  margin-top: 0;
}

.source-box {
  padding: 24px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: #f8fafc;
}

.source-box a {
  color: #0f766e;
  font-weight: 800;
  text-decoration: underline;
  text-underline-offset: 4px;
}

.seo-faq details {
  margin-bottom: 12px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: white;
}

.seo-faq summary {
  padding: 16px 18px;
  color: var(--primary);
  cursor: pointer;
  font-weight: 900;
  list-style: none;
}

.seo-faq summary::-webkit-details-marker {
  display: none;
}

.seo-faq p {
  padding: 0 18px 18px;
}

.article-body ul,
.article-body ol {
  padding-left: 1.4rem;
  margin: 0 0 24px;
}

.article-body li {
  margin: 7px 0;
}

.summary-box,
.note-box,
.cta-box,
.toc {
  border-radius: 8px;
  border: 1px solid var(--border);
  background: white;
}

.summary-box {
  padding: 24px;
  background: #fff7ed;
  border-color: #fed7aa;
}

.summary-box strong {
  color: #9a3412;
}

.note-box {
  padding: 20px;
  background: #f8fafc;
}

.toc {
  padding: 22px;
  margin-bottom: 30px;
  background: var(--bg-light);
}

.toc-title {
  margin: 0 0 10px;
  color: var(--primary);
  font-weight: 900;
}

.toc ol {
  margin-bottom: 0;
}

.table-wrap {
  overflow-x: auto;
  margin: 20px 0 30px;
  border: 1px solid var(--border);
  border-radius: 8px;
}

table {
  width: 100%;
  border-collapse: collapse;
  min-width: 680px;
  background: white;
}

th,
td {
  padding: 15px;
  border-bottom: 1px solid var(--border);
  text-align: left;
  vertical-align: top;
}

th {
  background: #f1f5f9;
  color: var(--primary);
}

tr:last-child td {
  border-bottom: 0;
}

.badge-good,
.badge-bad,
.badge-neutral {
  display: inline-block;
  padding: 2px 8px;
  border-radius: 999px;
  font-size: 0.82rem;
  font-weight: 900;
}

.badge-good {
  background: #dcfce7;
  color: var(--good);
}

.badge-bad {
  background: #fee2e2;
  color: var(--bad);
}

.badge-neutral {
  background: #e0f2fe;
  color: #075985;
}

.cta-box {
  margin: 42px 0;
  padding: 28px;
  background: linear-gradient(135deg, #0f172a 0%, #1f2937 100%);
  color: white;
}

.cta-box h2,
.cta-box p {
  color: white;
}

.cta-box h2 {
  margin-top: 0;
  border-bottom: 0;
}

.related-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
  margin-top: 18px;
}

.related-card {
  display: block;
  min-height: 132px;
  padding: 18px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: white;
}

.related-card:hover {
  border-color: #fbbf24;
  box-shadow: 0 12px 24px rgba(15, 23, 42, 0.08);
}

.related-card span {
  display: block;
  margin-bottom: 8px;
  color: var(--accent);
  font-size: 0.78rem;
  font-weight: 900;
}

.related-card strong {
  color: var(--primary);
  line-height: 1.45;
}

.sidebar {
  position: sticky;
  top: 94px;
}

.side-card {
  padding: 22px;
  margin-bottom: 18px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--bg-light);
}

.side-card h2 {
  margin: 0 0 12px;
  color: var(--primary);
  font-size: 1.08rem;
}

.side-card a:not(.btn) {
  display: block;
  padding: 10px 0;
  border-top: 1px solid var(--border);
  color: var(--secondary);
  font-size: 0.9rem;
  font-weight: 700;
  line-height: 1.5;
}

.side-card a:not(.btn):first-of-type {
  border-top: 0;
}

.side-card .btn {
  width: 100%;
  margin-top: 4px;
}

.site-footer {
  padding: 44px 0;
  background: var(--primary);
  color: #cbd5e1;
  text-align: center;
  font-size: 0.86rem;
}

.affiliate-pixel {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  opacity: 0;
  pointer-events: none;
}

.sitemap-body {
  padding-bottom: 72px;
}

.sitemap-section {
  margin-top: 38px;
}

.sitemap-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.sitemap-grid a {
  display: block;
  padding: 18px 20px;
  border: 1px solid #dbe4ec;
  border-radius: 8px;
  background: #fff;
  color: var(--primary);
  text-decoration: none;
  box-shadow: 0 10px 24px rgba(15, 23, 42, 0.06);
  transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
}

.sitemap-grid a:hover {
  transform: translateY(-2px);
  border-color: rgba(20, 184, 166, 0.55);
  box-shadow: 0 16px 30px rgba(15, 23, 42, 0.1);
}

.sitemap-grid strong {
  display: block;
  font-size: 1rem;
}

.sitemap-grid span {
  display: block;
  margin-top: 6px;
  color: var(--muted);
  font-size: 0.9rem;
  line-height: 1.7;
}

@media (max-width: 860px) {
  .header-inner {
    align-items: flex-start;
    flex-direction: column;
    padding: 12px 0;
  }

  .header-nav {
    width: 100%;
    justify-content: space-between;
  }

  .header-nav a:not(.btn) {
    display: none;
  }

  .sitemap-grid {
    grid-template-columns: 1fr;
  }

  .header-nav .btn {
    width: 100%;
  }

  .article-hero {
    padding: 44px 0 34px;
  }

  .main-wrap {
    display: block;
    padding: 40px 0;
  }

  .sidebar {
    position: static;
    margin-top: 36px;
  }

  .related-grid {
    grid-template-columns: 1fr;
  }
}