/* ===== Reset ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { -webkit-text-size-adjust: 100%; line-height: 1.15; }

/* ===== Base ===== */
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Hiragino Kaku Gothic ProN",
    "Hiragino Sans", Meiryo, sans-serif;
  font-size: 16px;
  line-height: 1.8;
  color: #1e293b;
  background-color: #ffffff;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ===== Back to Index ===== */
.back-to-index {
  margin-bottom: 24px;
}
.back-to-index a {
  display: inline-flex;
  align-items: center;
  font-size: 14px;
  color: #64748b;
  text-decoration: none;
  transition: color 0.2s;
}
.back-to-index a:hover {
  color: #2563eb;
}

/* ===== Layout ===== */
.article-body {
  max-width: 800px;
  margin: 0 auto;
  padding: 40px 24px 80px;
}

@media (max-width: 640px) {
  .article-body {
    padding: 24px 16px 60px;
  }
}

/* ===== Article Dates ===== */
.article-dates {
  font-size: 0.875rem;
  color: #64748b;
  margin-bottom: 1.5rem;
}

/* ===== Typography ===== */
.article-body h1 {
  font-size: 1.875rem;
  font-weight: 700;
  line-height: 1.3;
  color: #0f172a;
  margin-bottom: 1.5rem;
  letter-spacing: -0.01em;
}

.article-body h2 {
  font-size: 1.5rem;
  font-weight: 600;
  line-height: 1.4;
  color: #0f172a;
  margin-top: 3rem;
  margin-bottom: 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid #e2e8f0;
}

.article-body h3 {
  font-size: 1.25rem;
  font-weight: 600;
  line-height: 1.4;
  color: #1e293b;
  margin-top: 2.5rem;
  margin-bottom: 0.75rem;
}

.article-body h4 {
  font-size: 1.125rem;
  font-weight: 600;
  color: #1e293b;
  margin-top: 2rem;
  margin-bottom: 0.5rem;
}

.article-body p {
  margin-bottom: 1.25rem;
  color: #334155;
}

.article-body strong {
  font-weight: 600;
  color: #0f172a;
}

.article-body em {
  font-style: italic;
}

/* ===== Links ===== */
.article-body a {
  color: #2563eb;
  text-decoration: underline;
  text-decoration-color: #93c5fd;
  text-underline-offset: 2px;
  transition: color 0.15s, text-decoration-color 0.15s;
}

.article-body a:hover {
  color: #1d4ed8;
  text-decoration-color: #1d4ed8;
}

/* ===== Images ===== */
.article-body img {
  max-width: 100%;
  height: auto;
  border-radius: 8px;
  margin: 1.5rem 0;
  display: block;
}

.article-body figure {
  margin: 1.5rem 0;
}

.article-body figcaption {
  font-size: 0.875rem;
  color: #64748b;
  text-align: center;
  margin-top: 0.5rem;
}

/* ===== Lists ===== */
.article-body ul,
.article-body ol {
  margin-bottom: 1.25rem;
  padding-left: 1.75rem;
}

.article-body ul {
  list-style-type: disc;
}

.article-body ol {
  list-style-type: decimal;
}

.article-body li {
  margin-bottom: 0.375rem;
  color: #334155;
}

.article-body li > ul,
.article-body li > ol {
  margin-top: 0.375rem;
  margin-bottom: 0;
}

/* ===== Blockquote ===== */
.article-body blockquote {
  margin: 1.5rem 0;
  padding: 1rem 1.25rem;
  border-left: 4px solid #3b82f6;
  background-color: #f8fafc;
  border-radius: 0 8px 8px 0;
  color: #475569;
}

.article-body blockquote p:last-child {
  margin-bottom: 0;
}

/* ===== Table ===== */
.article-body table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5rem 0;
  font-size: 0.9375rem;
  overflow-x: auto;
  display: block;
}

@media (min-width: 641px) {
  .article-body table {
    display: table;
  }
}

.article-body thead th {
  background-color: #f1f5f9;
  font-weight: 600;
  color: #0f172a;
  text-align: left;
  padding: 0.75rem 1rem;
  border-bottom: 2px solid #cbd5e1;
}

.article-body tbody td {
  padding: 0.75rem 1rem;
  border-bottom: 1px solid #e2e8f0;
  color: #334155;
}

.article-body tbody tr:hover {
  background-color: #f8fafc;
}

/* ===== Code ===== */
.article-body code {
  font-family: "SF Mono", "Fira Code", "Fira Mono", Menlo, Consolas, monospace;
  font-size: 0.875em;
  background-color: #f1f5f9;
  color: #be185d;
  padding: 0.15em 0.4em;
  border-radius: 4px;
}

.article-body pre {
  margin: 1.5rem 0;
  padding: 1.25rem;
  background-color: #1e293b;
  border-radius: 8px;
  overflow-x: auto;
  line-height: 1.6;
}

.article-body pre code {
  background-color: transparent;
  color: #e2e8f0;
  padding: 0;
  font-size: 0.875rem;
}

/* ===== Horizontal Rule ===== */
.article-body hr {
  border: none;
  border-top: 1px solid #e2e8f0;
  margin: 2.5rem 0;
}

/* ===== Definition List ===== */
.article-body dl {
  margin-bottom: 1.25rem;
}

.article-body dt {
  font-weight: 600;
  color: #0f172a;
  margin-top: 1rem;
}

.article-body dd {
  margin-left: 1.5rem;
  color: #334155;
}

/* ===== iframe (YouTube等) ===== */
.article-body iframe {
  max-width: 100%;
  margin: 1.5rem 0;
  border-radius: 8px;
}

/* ===== Author Footer ===== */
.author-footer-container {
  display: flex;
  align-items: flex-start;
  border-top: 2px solid #e0e0e0;
  padding: 25px;
  margin-top: 30px;
  background-color: #f9f9f9;
  border-radius: 8px;
  box-shadow: 0 2px 5px rgba(0, 0, 0, 0.05);
}

.author-footer-image-wrapper {
  flex-shrink: 0;
  margin-right: 20px;
}

.article-body .author-footer-image {
  width: 100px;
  height: 100px;
  min-width: 100px;
  border-radius: 50%;
  object-fit: cover;
  border: 1px solid #ddd;
  display: inline-block;
  margin: 0;
}

.author-footer-info p {
  margin: 0 0 5px 0;
  color: #343a40;
  line-height: 1.5;
}

.author-footer-name {
  font-size: 1.3em;
  font-weight: bold;
  margin-bottom: 8px;
}

.author-footer-title,
.author-footer-organization {
  font-size: 1em;
  color: #555;
}

.author-footer-bio {
  font-size: 0.95em;
  color: #444;
}

.author-footer-links a {
  color: #2563eb;
  text-decoration: none;
  margin-right: 12px;
  font-size: 0.9em;
}

.author-footer-links a:hover {
  text-decoration: underline;
}

.author-footer-published-at {
  font-size: 0.9em;
  color: #777;
  margin-top: 10px;
}

.author-footer-name {
  cursor: pointer;
  transition: color 0.2s;
}
.author-footer-name:hover {
  color: #2563eb;
  text-decoration: underline;
}

/* ===== Author Profile Modal ===== */
.author-modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.5);
  z-index: 9999;
  display: flex;
  align-items: center;
  justify-content: center;
}
.author-modal {
  position: relative;
  background: #fff;
  border-radius: 12px;
  box-shadow: 0 8px 32px rgba(0,0,0,0.2);
  max-width: 480px;
  width: 90%;
  max-height: 80vh;
  overflow-y: auto;
  padding: 32px;
  text-align: center;
}
.author-modal-close {
  position: absolute;
  top: 12px;
  right: 16px;
  background: none;
  border: none;
  font-size: 24px;
  color: #94a3b8;
  cursor: pointer;
  line-height: 1;
}
.author-modal-close:hover {
  color: #475569;
}
.author-modal-image {
  width: 120px;
  height: 120px;
  border-radius: 50%;
  object-fit: cover;
  border: 1px solid #ddd;
  margin-bottom: 16px;
}
.author-modal-name {
  font-size: 1.5em;
  font-weight: bold;
  color: #1e293b;
  margin-bottom: 4px;
}
.author-modal-title {
  font-size: 1em;
  color: #475569;
  margin-bottom: 2px;
}
.author-modal-organization {
  font-size: 0.9em;
  color: #64748b;
}
.author-modal-divider {
  border: none;
  border-top: 1px solid #e2e8f0;
  margin: 20px 0;
}
.author-modal-bio-label {
  font-size: 0.85em;
  font-weight: 600;
  color: #475569;
  margin-bottom: 8px;
  text-align: left;
}
.author-modal-bio {
  font-size: 0.95em;
  color: #475569;
  line-height: 1.8;
  white-space: pre-wrap;
  text-align: left;
}
.author-modal-links {
  text-align: left;
}
.author-modal-links a {
  display: block;
  color: #2563eb;
  text-decoration: none;
  font-size: 0.9em;
  margin-bottom: 6px;
}
.author-modal-links a:hover {
  text-decoration: underline;
}

@media (max-width: 640px) {
  .author-footer-container {
    flex-direction: column;
    align-items: center;
    text-align: center;
  }
  .author-footer-image-wrapper {
    margin-right: 0;
    margin-bottom: 15px;
  }
  .author-modal {
    padding: 24px 16px;
  }
}

/* ===== Custom CSS ===== */
/* ===== カスタムCSS：上品で信頼感のあるコラムサイト向け ===== */

/* 全体設計
   - 読みやすさ重視
   - 落ち着いた配色
   - コラム/企業メディア/専門サイトに馴染みやすいデザイン
*/

/* =========================
   記事ページ
   ========================= */

.article-body {
  max-width: 760px;
  margin: 0 auto;
  padding: 40px 20px 72px;
  color: #2b2f38;
  font-size: 16px;
  line-height: 1.95;
  letter-spacing: 0.02em;
}

.article-body h1,
.article-body h2,
.article-body h3,
.article-body h4 {
  color: #1d2736;
  line-height: 1.45;
  letter-spacing: 0.03em;
  font-weight: 700;
}

.article-body h1 {
  font-size: 2rem;
  margin: 0 0 1.2em;
  padding-bottom: 0.45em;
  border-bottom: 2px solid #d9e2ec;
}

.article-body h2 {
  font-size: 1.55rem;
  margin: 2.8em 0 1em;
  padding-left: 0.8em;
  border-left: 5px solid #54708c;
}

.article-body h3 {
  font-size: 1.2rem;
  margin: 2.2em 0 0.9em;
  padding-bottom: 0.35em;
  border-bottom: 1px solid #dfe7ef;
}

.article-body h4 {
  font-size: 1.02rem;
  margin: 1.8em 0 0.7em;
  color: #425466;
}

.article-body p {
  margin: 0 0 1.4em;
}

.article-body a {
  color: #2b5f8a;
  text-decoration: none;
  border-bottom: 1px solid rgba(43, 95, 138, 0.35);
  transition: all 0.25s ease;
}

.article-body a:hover {
  color: #173b59;
  border-bottom-color: rgba(23, 59, 89, 0.7);
}

.article-body img {
  display: block;
  max-width: 100%;
  height: auto;
  margin: 2em auto;
  border-radius: 14px;
  box-shadow: 0 10px 30px rgba(21, 34, 50, 0.10);
}

.article-body blockquote {
  margin: 2em 0;
  padding: 1.2em 1.4em;
  background: #f7fafc;
  border-left: 4px solid #7b95ad;
  border-radius: 10px;
  color: #425466;
}

.article-body table {
  width: 100%;
  border-collapse: collapse;
  margin: 2em 0;
  background: #ffffff;
  border: 1px solid #dfe7ef;
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 6px 18px rgba(20, 35, 55, 0.05);
}

.article-body thead th {
  background: #eef4f8;
  color: #243447;
  font-weight: 700;
  padding: 14px 16px;
  border-bottom: 1px solid #d9e2ec;
  text-align: left;
}

.article-body table td {
  padding: 14px 16px;
  border-bottom: 1px solid #edf2f7;
}

.article-body table tr:last-child td {
  border-bottom: none;
}

.author-footer-container {
  margin-top: 56px;
  padding: 24px 28px;
  background: linear-gradient(135deg, #f8fbfd 0%, #eef4f8 100%);
  border: 1px solid #dde7f0;
  border-radius: 16px;
  box-shadow: 0 8px 24px rgba(20, 35, 55, 0.05);
}

.back-to-index a {
  display: inline-block;
  margin-top: 24px;
  color: #2b5f8a;
  text-decoration: none;
  font-weight: 600;
  transition: opacity 0.25s ease, transform 0.25s ease;
}

.back-to-index a:hover {
  opacity: 0.8;
  transform: translateX(-2px);
}

/* =========================
   記事一覧ページ
   ========================= */

.hero {
  position: relative;
  padding: 88px 20px 84px;
  text-align: center;
  color: #ffffff;
  background:
    linear-gradient(135deg, #243447 0%, #3b4f63 55%, #6c8398 100%);
  overflow: hidden;
}

.hero--bg-image::before {
  background: rgba(26, 26, 46, 0);
}

.hero__title {
  position: relative;
  z-index: 1;
  margin: 0 0 14px;
  font-size: 2.4rem;
  line-height: 1.3;
  letter-spacing: 0.06em;
  font-weight: 700;
}

.hero__subtitle {
  position: relative;
  z-index: 1;
  max-width: 760px;
  margin: 0 auto;
  font-size: 1rem;
  line-height: 1.9;
  color: rgba(255, 255, 255, 0.88);
  letter-spacing: 0.04em;
}

.article-card {
  background: #ffffff;
  border: 1px solid #e6edf3;
  border-radius: 18px;
  box-shadow: 0 10px 28px rgba(19, 34, 50, 0.06);
  transition:
    transform 0.28s ease,
    box-shadow 0.28s ease,
    border-color 0.28s ease;
}

.article-card:hover {
  transform: translateY(-4px);
  border-color: #d3dee8;
  box-shadow: 0 16px 36px rgba(19, 34, 50, 0.10);
}

/* =========================
   レスポンシブ
   ========================= */

@media (max-width: 768px) {
  .article-body {
    padding: 28px 16px 56px;
    font-size: 15.5px;
    line-height: 1.88;
  }

  .article-body h1 {
    font-size: 1.7rem;
  }

  .article-body h2 {
    font-size: 1.35rem;
  }

  .article-body h3 {
    font-size: 1.1rem;
  }

  .hero {
    padding: 64px 16px 60px;
  }

  .hero__title {
    font-size: 1.9rem;
  }

  .hero__subtitle {
    font-size: 0.95rem;
    line-height: 1.8;
  }

  .author-footer-container {
    padding: 20px;
  }
}