:root {
  --primary-color: #4a6da7;
  --secondary-color: #f8f9fa;
  --accent-color: #666;
  --text-color: #333;
  --light-text-color: #666;
  --border-color: #ddd;
  --success-color: #28a745;
  --warning-color: #ffc107;
  --info-color: #17a2b8;
  --font-family: "Noto Sans JP", -apple-system, BlinkMacSystemFont, "Segoe UI",
    Roboto, "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Meiryo", sans-serif;
}

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

body {
  font-family: var(--font-family);
  line-height: 1.6;
  color: var(--text-color);
  background-color: #fff;
}

.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 15px;
}

a {
  color: var(--primary-color);
  text-decoration: none;
  transition: color 0.3s;
}

a:hover {
  color: #2c4a7c;
  text-decoration: underline;
}

h1,
h2,
h3,
h4,
h5,
h6 {
  margin-bottom: 0.5em;
  font-weight: 500;
  line-height: 1.2;
}

p {
  margin-bottom: 1rem;
}

img {
  max-width: 100%;
  height: auto;
}

ul,
ol {
  margin-bottom: 1rem;
  padding-left: 2rem;
}

.site-header {
  background-color: var(--primary-color);
  color: white;
  padding: 1rem 0;
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.site-header .container {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
}

.site-title {
  font-size: 1.5rem;
  margin: 0;
}

.site-title a {
  color: white;
  text-decoration: none;
}

.site-nav ul {
  display: flex;
  list-style: none;
  margin: 0;
  padding: 0;
}

.site-nav li {
  margin-left: 1.5rem;
}

.site-nav a {
  color: white;
  text-decoration: none;
  font-weight: 500;
}

.site-nav a:hover {
  text-decoration: underline;
}

.site-footer {
  background-color: var(--secondary-color);
  padding: 2rem 0;
  margin-top: 3rem;
  border-top: 1px solid var(--border-color);
}

.site-footer .container {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
}

.footer-nav ul {
  display: flex;
  list-style: none;
  margin: 0;
  padding: 0;
}

.footer-nav li {
  margin-left: 1rem;
}

.footer-nav a {
  color: var(--light-text-color);
  text-decoration: none;
  font-size: 0.9rem;
}

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

.site-content {
  padding: 2rem 0;
}

.hero {
  background-color: var(--secondary-color);
  padding: 3rem 0;
  text-align: center;
  margin-bottom: 2rem;
  border-radius: 8px;
}

.hero h1 {
  font-size: 2.5rem;
  margin-bottom: 1rem;
}

.hero p {
  font-size: 1.2rem;
  color: var(--light-text-color);
  margin-bottom: 2rem;
}

.quick-calculator {
  max-width: 600px;
  margin: 0 auto;
  background-color: white;
  padding: 1.5rem;
  border-radius: 8px;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.quick-calculator h2 {
  margin-bottom: 1.5rem;
  text-align: center;
}

.form-group {
  margin-bottom: 1rem;
}

.form-group label {
  display: block;
  margin-bottom: 0.5rem;
  font-weight: 500;
}

.date-inputs {
  display: flex;
  gap: 10px;
}

.date-inputs select {
  flex: 1;
  padding: 0.5rem;
  border: 1px solid var(--border-color);
  border-radius: 4px;
  font-size: 1rem;
}

.btn {
  display: inline-block;
  background-color: var(--primary-color);
  color: white;
  padding: 0.5rem 1.5rem;
  border: none;
  border-radius: 4px;
  font-size: 1rem;
  cursor: pointer;
  transition: background-color 0.3s;
}

.btn:hover {
  background-color: #2c4a7c;
  text-decoration: none;
  color: white;
}

.btn-small {
  padding: 0.25rem 0.75rem;
  font-size: 0.9rem;
}

.result-box {
  margin-top: 1.5rem;
  padding: 1rem;
  background-color: #f8f9fa;
  border-radius: 4px;
  border-left: 4px solid var(--primary-color);
}

.featured-content {
  margin-bottom: 3rem;
}

.section-heading {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1.5rem;
  border-bottom: 2px solid var(--border-color);
  padding-bottom: 0.5rem;
}

.section-heading h2 {
  margin-bottom: 0;
}

.view-all {
  font-size: 0.9rem;
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 20px;
}

.card {
  border: 1px solid var(--border-color);
  border-radius: 8px;
  overflow: hidden;
  transition: transform 0.3s, box-shadow 0.3s;
}

.card:hover {
  transform: translateY(-5px);
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

.card-image {
  width: 100%;
  height: 200px;
  object-fit: cover;
}

.card-content {
  padding: 1rem;
}

.card-content h3 {
  margin-bottom: 0.5rem;
}

.event-date,
.celeb-info,
.generation-years {
  color: var(--light-text-color);
  font-size: 0.9rem;
  margin-bottom: 0.5rem;
}

.read-more {
  display: inline-block;
  margin-top: 0.5rem;
  font-weight: 500;
}

.birth-year-section {
  margin: 3rem 0;
  padding: 2rem 0;
  background: var(--secondary-color);
  border-radius: 8px;
}

.birth-year-section h2 {
  text-align: center;
  margin-bottom: 1rem;
  color: var(--primary-color);
}

.section-description {
  text-align: center;
  color: var(--light-text-color);
  margin-bottom: 2rem;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

.year-selection-container {
  max-width: 900px;
  margin: 0 auto;
  padding: 0 1rem;
}

.recent-years-section {
  margin-bottom: 3rem;
}

.recent-years-title {
  color: var(--primary-color);
  font-size: 1.2rem;
  margin-bottom: 1.5rem;
  text-align: center;
  font-weight: 600;
}

.recent-years-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1rem;
}

.year-link-card {
  display: flex;
  align-items: center;
  padding: 1rem 1.5rem;
  background: white;
  border: 1px solid var(--border-color);
  border-radius: 8px;
  text-decoration: none;
  color: inherit;
  transition: all 0.3s ease;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
}

.year-link-card:hover {
  border-color: var(--primary-color);
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
  text-decoration: none;
  color: inherit;
}

.year-badge {
  display: inline-block;
  background: var(--primary-color);
  color: white;
  padding: 0.5rem 1rem;
  border-radius: 6px;
  font-weight: bold;
  font-size: 1rem;
  margin-right: 1rem;
  min-width: 80px;
  text-align: center;
}

.year-details {
  color: var(--light-text-color);
  font-size: 0.9rem;
  line-height: 1.4;
}

.current-age {
  text-align: center;
  font-size: 1.4rem;
  font-weight: bold;
  color: var(--primary-color);
  background: var(--secondary-color);
  padding: 0.5rem;
  border-radius: 6px;
}

.more-years-coming {
  text-align: center;
  margin-top: 2rem;
  padding: 1rem;
}

.more-years-coming p {
  color: var(--light-text-color);
  font-style: italic;
  margin: 0;
}

.tools-section {
  background-color: var(--secondary-color);
  padding: 2rem;
  border-radius: 8px;
  margin-bottom: 3rem;
}

.tools-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-top: 1.5rem;
}

.tool-card {
  background-color: white;
  padding: 1.5rem;
  border-radius: 8px;
  box-shadow: 0 2px 5px rgba(0, 0, 0, 0.05);
  text-align: center;
  height: 100%;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.tool-card h3 {
  margin-bottom: 0.5rem;
}

.tool-card p {
  margin-bottom: 1.5rem;
  color: var(--light-text-color);
  flex-grow: 1;
}

.tool-card .btn {
  align-self: center;
}

.post-header,
.celebrity-header,
.event-header,
.generation-header,
.calculator-header {
  margin-bottom: 2rem;
}

.post-title,
.celebrity-name,
.event-title,
.generation-title,
.calculator-title {
  font-size: 2rem;
  margin-bottom: 0.5rem;
}

.post-meta,
.celebrity-meta,
.event-meta,
.generation-meta {
  color: var(--light-text-color);
  margin-bottom: 1rem;
}

.post-content,
.celebrity-content,
.event-content,
.generation-content,
.calculator-content {
  margin-bottom: 2rem;
}

.post-tags {
  margin-top: 2rem;
}

.post-navigation {
  display: flex;
  justify-content: space-between;
  margin: 2rem 0;
  padding: 1rem 0;
  border-top: 1px solid var(--border-color);
  border-bottom: 1px solid var(--border-color);
}

.post-navigation-prev,
.post-navigation-next {
  max-width: 45%;
}

.nav-label {
  display: block;
  font-size: 0.9rem;
  color: var(--light-text-color);
}

.nav-title {
  font-weight: 500;
}

.related-posts,
.related-celebrities,
.related-events {
  margin-top: 2rem;
  padding: 1.5rem;
  background-color: var(--secondary-color);
  border-radius: 8px;
}

.related-posts h3,
.related-celebrities h2,
.related-events h2 {
  margin-bottom: 1rem;
}

.related-posts ul,
.related-celebrities ul,
.related-events ul {
  list-style: none;
  padding: 0;
}

.related-posts li,
.related-celebrities li,
.related-events li {
  margin-bottom: 0.5rem;
}

.related-posts small,
.related-celebrities small,
.related-events small {
  color: var(--light-text-color);
  font-size: 0.9rem;
  margin-left: 0.5rem;
}

.celebrity-image {
  margin-bottom: 2rem;
  text-align: center;
}

.celebrity-image img {
  max-width: 100%;
  max-height: 400px;
  border-radius: 8px;
}

.celebrity-meta div,
.event-meta div,
.generation-meta div {
  margin-bottom: 0.5rem;
}

.label {
  font-weight: 500;
  margin-right: 0.5rem;
}

.celebrity-achievements,
.event-significance,
.generation-characteristics,
.generation-key-events {
  margin-top: 2rem;
  padding: 1.5rem;
  background-color: #f8f9fa;
  border-radius: 8px;
  border-left: 4px solid var(--primary-color);
}

.age-comparison,
.same-day-events,
.generation-navigation,
.calculator-navigation {
  margin-top: 3rem;
}

/* 計算ツール */
.calculator-tool {
  margin: 2rem 0;
  padding: 2rem;
  background-color: var(--secondary-color);
  border-radius: 8px;
}

.calculator-form {
  max-width: 600px;
  margin: 0 auto;
}

.calculator-description {
  font-size: 1.1rem;
  color: var(--light-text-color);
  margin-bottom: 1.5rem;
}

.calculator-nav-grid,
.generation-nav-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  gap: 15px;
  margin-top: 1rem;
}

.calculator-nav-item,
.generation-nav-item {
  display: block;
  padding: 1rem;
  background-color: var(--secondary-color);
  border-radius: 8px;
  transition: background-color 0.3s;
}

.calculator-nav-item:hover,
.generation-nav-item:hover {
  background-color: #e9ecef;
  text-decoration: none;
}

.calculator-nav-item h3,
.generation-nav-item h3 {
  margin-bottom: 0.25rem;
  font-size: 1.1rem;
}

.calculator-nav-item p,
.generation-nav-item p {
  margin-bottom: 0;
  font-size: 0.9rem;
  color: var(--light-text-color);
}

.age-result {
  font-size: 1.5rem;
  text-align: center;
  margin-bottom: 1rem;
}

/* 年齢早見表 */
.age-table {
  margin: 2rem 0 3rem;
}

.table-note {
  margin-bottom: 1rem;
  color: #666;
  font-weight: 500;
}

.table-container {
  overflow-x: auto;
}

.age-reference-table {
  width: 100%;
  border-collapse: collapse;
  border: 1px solid #ddd;
}

.age-reference-table th {
  background-color: #f5f5f5;
  color: #333;
  text-align: center;
  padding: 0.5rem;
  border: 1px solid #ddd;
  font-weight: 600;
}

.age-reference-table td {
  padding: 0.5rem;
  text-align: center;
  border: 1px solid #ddd;
}

.age-reference-table .age {
  font-weight: bold;
  color: #333;
}

.age-reference-table tr:nth-child(even) {
  background-color: #f9f9f9;
}

.age-reference-table tr:hover {
  background-color: #f0f0f0;
}

.age-table h2 {
  text-align: center;
  margin-bottom: 1rem;
  color: #333;
  border-bottom: 1px solid #ddd;
  padding-bottom: 0.5rem;
}

@media (max-width: 768px) {
  .site-header .container {
    flex-direction: column;
    align-items: flex-start;
  }

  .site-nav {
    margin-top: 1rem;
    width: 100%;
  }

  .site-nav ul {
    flex-direction: column;
  }

  .site-nav li {
    margin-left: 0;
    margin-bottom: 0.5rem;
  }

  .site-footer .container {
    flex-direction: column;
    align-items: flex-start;
  }

  .footer-nav {
    margin-top: 1rem;
  }

  .footer-nav ul {
    flex-direction: column;
  }

  .footer-nav li {
    margin-left: 0;
    margin-bottom: 0.5rem;
  }

  .card-grid,
  .tools-grid {
    grid-template-columns: 1fr;
  }

  .post-navigation {
    flex-direction: column;
  }

  .post-navigation-prev,
  .post-navigation-next {
    max-width: 100%;
    margin-bottom: 1rem;
  }

  .date-inputs {
    flex-direction: column;
  }

  .age-reference-table {
    font-size: 0.9rem;
  }

  .age-reference-table td,
  .age-reference-table th {
    padding: 0.3rem;
  }

  .age-reference-table th:nth-child(n + 4),
  .age-reference-table td:nth-child(n + 4) {
    display: none;
  }

  .age-reference-table th,
  .age-reference-table td {
    width: auto;
  }

  .mobile-age-table {
    display: block;
    margin-top: 2rem;
  }

  .desktop-only {
    display: none;
  }
}

@media (min-width: 769px) {
  .mobile-age-table {
    display: none;
  }

  .desktop-only {
    display: table-cell;
  }
}

@media (max-width: 992px) {
  .tools-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .tools-grid {
    grid-template-columns: 1fr;
  }

  .recent-years-grid {
    grid-template-columns: 1fr;
    gap: 0.75rem;
  }

  .year-link-card {
    padding: 0.75rem 1rem;
  }

  .year-badge {
    min-width: 70px;
    font-size: 0.9rem;
    padding: 0.4rem 0.8rem;
    margin-right: 0.75rem;
  }

  .year-details {
    font-size: 0.85rem;
  }
}

.ad-container {
  text-align: center;
  margin: 20px 0;
  padding: 10px;
  background-color: #f9f9f9;
  border-radius: 5px;
  overflow: hidden;
  clear: both;
}

.ad-container:before {
  content: "広告";
  display: block;
  font-size: 10px;
  color: #999;
  margin-bottom: 5px;
  text-align: center;
}

.ad-top {
  margin-top: 0;
}

.ad-content-bottom {
  margin-top: 30px;
}

.ad-result {
  margin-top: 20px;
}

.ad-before-nav {
  margin: 30px 0;
}

.ad-quick-calc {
  margin-top: 15px;
}

.ad-before-table,
.ad-after-table {
  max-width: 100%;
  margin: 25px auto;
}

@media (max-width: 768px) {
  .ad-container {
    margin: 15px 0;
    padding: 8px;
  }
}