:root {
  --primary-color: #00C9A7;
  --secondary-color: #0066FF;
  --accent-color: #FFB800;
  --dark-bg: #1B2A3D;
  --light-bg: #F5F9FC;
  --text-dark: #2C3E50;
  --text-light: #6C757D;
  --white: #FFFFFF;
  --gradient-primary: linear-gradient(135deg, #00C9A7 0%, #0066FF 100%);
  --gradient-secondary: linear-gradient(135deg, #0066FF 0%, #00C9A7 100%);
  --shadow-sm: 0 2px 10px rgba(0,0,0,0.08);
  --shadow-md: 0 4px 20px rgba(0,0,0,0.12);
  --shadow-lg: 0 10px 40px rgba(0,0,0,0.15);
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --facebook-blue: #1877F2;
  --x-black: #000000;
  --line-green: #00B900;
}

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

body {
  font-family: 'Noto Sans JP', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  line-height: 1.7;
  color: var(--text-dark);
  background: var(--white);
  overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: 1rem;
  color: var(--dark-bg);
}

h1 { font-size: 3rem; }
h2 { font-size: 2.5rem; }
h3 { font-size: 2rem; }
h4 { font-size: 1.5rem; }
h5 { font-size: 1.25rem; }
h6 { font-size: 1rem; }

p {
  margin-bottom: 1.5rem;
  line-height: 1.8;
}

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

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

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

header {
  position: fixed;
  top: 0;
  width: 100%;
  background: rgba(255, 255, 255, 0.98);
  backdrop-filter: blur(20px);
  box-shadow: var(--shadow-sm);
  z-index: 1000;
  transition: var(--transition);
}

header.scrolled {
  box-shadow: var(--shadow-md);
}

nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 0;
  min-height: 80px;
}

.logo {
  font-size: 1.5rem;
  font-weight: 800;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.nav-menu {
  display: flex;
  list-style: none;
  gap: 1.5rem;
  align-items: center;
  flex-wrap: wrap;
  max-width: 900px;
  justify-content: center;
}

.nav-item a {
  font-weight: 500;
  color: var(--text-dark);
  padding: 0.4rem 0.8rem;
  border-radius: 8px;
  transition: var(--transition);
  font-size: 0.9rem;
  white-space: nowrap;
}

.nav-item a:hover {
  background: var(--light-bg);
  color: var(--primary-color);
}

.nav-item.active a {
  background: var(--gradient-primary);
  color: var(--white);
}

.hamburger {
  display: none;
  flex-direction: column;
  cursor: pointer;
  gap: 4px;
  z-index: 1001;
}

.hamburger span {
  width: 25px;
  height: 3px;
  background: var(--dark-bg);
  border-radius: 3px;
  transition: var(--transition);
}

.hamburger.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

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

.hamburger.active span:nth-child(3) {
  transform: rotate(-45deg) translate(7px, -6px);
}

.hero {
  margin-top: 80px;
  min-height: 600px;
  background: linear-gradient(135deg, rgba(0,201,167,0.9) 0%, rgba(0,102,255,0.9) 100%);
  position: relative;
  display: flex;
  align-items: center;
  overflow: hidden;
}

.hero-background {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.3;
  z-index: 0;
}

.hero-content {
  position: relative;
  z-index: 1;
  color: var(--white);
  padding: 4rem 0;
}

.hero h1 {
  color: var(--white);
  margin-bottom: 1.5rem;
  animation: fadeInUp 0.8s ease;
}

.hero-subtitle {
  font-size: 1.25rem;
  margin-bottom: 2rem;
  opacity: 0.95;
  animation: fadeInUp 1s ease;
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.section {
  padding: 5rem 0;
}

.section:nth-child(even) {
  background: var(--light-bg);
}

.section-header {
  text-align: center;
  margin-bottom: 3rem;
}

.section-title {
  margin-bottom: 1rem;
  position: relative;
  display: inline-block;
}

.section-title::after {
  content: '';
  position: absolute;
  bottom: -10px;
  left: 50%;
  transform: translateX(-50%);
  width: 80px;
  height: 4px;
  background: var(--gradient-primary);
  border-radius: 2px;
}

.section-subtitle {
  font-size: 1.1rem;
  color: var(--text-light);
  margin-top: 1.5rem;
}

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

.content-wrapper {
  max-width: 900px;
  margin: 0 auto;
}

.stats-container {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 2rem;
  margin: 3rem 0;
}

.stat-item {
  text-align: center;
  padding: 2rem;
  background: var(--white);
  border-radius: 12px;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
}

.stat-item:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-md);
}

.stat-number {
  font-size: 3rem;
  font-weight: 800;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 0.5rem;
}

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

.news-list {
  display: grid;
  gap: 1.5rem;
  max-width: 900px;
  margin: 0 auto;
}

.news-item {
  background: var(--white);
  padding: 2rem;
  border-radius: 12px;
  box-shadow: var(--shadow-sm);
  border-left: 4px solid var(--primary-color);
  transition: var(--transition);
}

.news-item:hover {
  box-shadow: var(--shadow-md);
  transform: translateX(5px);
}

.news-date {
  color: var(--primary-color);
  font-weight: 600;
  font-size: 0.9rem;
  margin-bottom: 0.5rem;
}

.news-title {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--dark-bg);
  margin-bottom: 0.75rem;
}

.news-text {
  color: var(--text-light);
  line-height: 1.7;
  margin-bottom: 0;
}

.article-layout {
  display: grid;
  grid-template-columns: 1fr 300px;
  gap: 3rem;
  margin-top: 2rem;
}

.article-main {
  min-width: 0;
}

.article-image {
  width: 100%;
  height: auto;
  border-radius: 12px;
  margin-bottom: 2rem;
  box-shadow: var(--shadow-md);
}

.sidebar {
  position: sticky;
  top: 100px;
  height: fit-content;
}

.sidebar-section {
  background: var(--white);
  padding: 1.5rem;
  border-radius: 12px;
  box-shadow: var(--shadow-sm);
  margin-bottom: 2rem;
}

.sidebar-title {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 1rem;
  color: var(--dark-bg);
  border-bottom: 2px solid var(--light-bg);
  padding-bottom: 0.5rem;
}

.toc-list {
  list-style: none;
}

.toc-list li {
  margin-bottom: 0.75rem;
}

.toc-list a {
  color: var(--text-dark);
  font-size: 0.9rem;
  transition: var(--transition);
  display: block;
  padding: 0.5rem;
  border-radius: 6px;
}

.toc-list a:hover {
  background: var(--light-bg);
  color: var(--primary-color);
}

.related-links {
  list-style: none;
}

.related-links li {
  margin-bottom: 0.75rem;
}

.related-links a {
  color: var(--text-dark);
  font-size: 0.9rem;
  transition: var(--transition);
  display: block;
  padding: 0.5rem;
  border-radius: 6px;
  border-left: 3px solid var(--primary-color);
  padding-left: 1rem;
}

.related-links a:hover {
  background: var(--light-bg);
  color: var(--primary-color);
}

.ad-space {
  background: var(--light-bg);
  padding: 2rem;
  text-align: center;
  border-radius: 8px;
  color: var(--text-light);
  font-size: 0.9rem;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 2rem;
  margin: 3rem 0;
}

.feature-card {
  background: var(--white);
  padding: 2rem;
  border-radius: 12px;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
}

.feature-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-md);
}

.feature-icon {
  font-size: 2.5rem;
  margin-bottom: 1rem;
}

.feature-card h3 {
  margin-bottom: 1rem;
  color: var(--dark-bg);
}

.feature-card p {
  color: var(--text-light);
  margin-bottom: 0;
}

footer {
  background: var(--dark-bg);
  color: var(--white);
  padding: 3rem 0 1.5rem;
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 2rem;
  margin-bottom: 2rem;
}

.footer-section h4 {
  color: var(--white);
  margin-bottom: 1rem;
}

.footer-links {
  list-style: none;
}

.footer-links li {
  margin-bottom: 0.5rem;
}

.footer-links a {
  color: rgba(255, 255, 255, 0.8);
  transition: var(--transition);
}

.footer-links a:hover {
  color: var(--primary-color);
}

.footer-bottom {
  text-align: center;
  padding-top: 2rem;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  color: rgba(255, 255, 255, 0.6);
  font-size: 0.9rem;
}

@media (max-width: 1024px) {
  .article-layout {
    grid-template-columns: 1fr;
    display: flex;
    flex-direction: column;
  }

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

  .article-main {
    order: 1;
  }
}

@media (max-width: 768px) {
  h1 { font-size: 2rem; }
  h2 { font-size: 1.75rem; }
  h3 { font-size: 1.5rem; }
  
  .nav-menu {
    position: fixed;
    top: 80px;
    left: -100%;
    width: 100%;
    height: calc(100vh - 80px);
    background: var(--white);
    flex-direction: column;
    justify-content: flex-start;
    padding: 2rem;
    gap: 0;
    transition: var(--transition);
    overflow-y: auto;
  }
  
  .nav-menu.active {
    left: 0;
  }
  
  .nav-item {
    width: 100%;
    text-align: center;
    border-bottom: 1px solid var(--light-bg);
  }
  
  .nav-item a {
    display: block;
    padding: 1rem;
    font-size: 1rem;
  }
  
  .hamburger {
    display: flex;
  }
  
  .hero {
    min-height: 400px;
  }
  
  .hero h1 {
    font-size: 1.75rem;
  }
  
  .hero-subtitle {
    font-size: 1rem;
  }
  
  .section {
    padding: 3rem 0;
  }
  
  .stats-container {
    grid-template-columns: repeat(2, 1fr);
    gap: 1rem;
  }
  
  .stat-item {
    padding: 1.5rem 1rem;
  }
  
  .stat-number {
    font-size: 2rem;
  }
  
  .footer-content {
    grid-template-columns: 1fr;
  }
  
  .nav-menu {
    gap: 0;
  }
  
  .nav-item a {
    font-size: 1rem;
    padding: 1rem;
  }
  
  nav {
    min-height: 60px;
  }
}

/* ブログページ専用スタイル */
.article-main {
  margin-top: 80px;
  padding: 2rem 0;
}

.article-header {
  text-align: center;
  margin-bottom: 2rem;
}

.article-meta {
  display: flex;
  justify-content: center;
  gap: 1rem;
  align-items: center;
  margin-top: 1rem;
  color: var(--text-light);
  font-size: 0.9rem;
}

.article-hero {
  margin-bottom: 3rem;
  text-align: center;
}

.hero-image {
  width: 100%;
  max-width: 800px;
  height: auto;
  object-fit: cover;
  border-radius: 12px;
  box-shadow: var(--shadow-md);
  margin: 0 auto;
  display: block;
}

.article-content {
  max-width: 800px;
  margin: 0 auto;
  line-height: 1.8;
}

.article-content h2 {
  margin: 2.5rem 0 1rem 0;
  color: var(--dark-bg);
}

.article-content h3 {
  margin: 2rem 0 0.75rem 0;
  color: var(--dark-bg);
}

.article-content blockquote {
  background: var(--light-bg);
  border-left: 4px solid var(--primary-color);
  margin: 2rem 0;
  padding: 1.5rem;
  font-style: italic;
  border-radius: 0 8px 8px 0;
}

.article-content ul, .article-content ol {
  margin: 1rem 0;
  padding-left: 2rem;
}

.article-content li {
  margin: 0.5rem 0;
}

.future-points {
  background: var(--light-bg);
  padding: 2rem;
  border-radius: 12px;
  margin: 2rem 0;
}

.future-points h3 {
  color: var(--primary-color);
  margin-bottom: 1rem;
}

.share-buttons {
  text-align: center;
  margin: 3rem 0;
  padding: 2rem;
  background: var(--light-bg);
  border-radius: 12px;
}

.share-button-group {
  display: flex;
  justify-content: center;
  gap: 1rem;
  margin-top: 1rem;
  flex-wrap: wrap;
}

.share-button {
  padding: 0.75rem 1.5rem;
  border-radius: 8px;
  text-decoration: none;
  font-weight: 600;
  font-size: 0.9rem;
  transition: var(--transition);
}

.share-button.facebook {
  background: var(--facebook-blue);
  color: white;
}

.share-button.twitter {
  background: var(--x-black);
  color: white;
}

.share-button.line {
  background: var(--line-green);
  color: white;
}

.share-button:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.related-articles {
  margin: 3rem 0;
}

.article-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1.5rem;
  margin: 2rem 0;
}

.article-card {
  background: var(--white);
  border-radius: 8px;
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
  text-decoration: none;
  color: inherit;
}

.article-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
}

.article-card img {
  width: 100%;
  height: 150px;
  object-fit: cover;
}

.article-card h4 {
  padding: 1rem;
  font-size: 1rem;
  margin: 0;
  color: var(--dark-bg);
}

.skip-link {
  position: absolute;
  top: -40px;
  left: 6px;
  background: #000;
  color: #fff;
  padding: 8px;
  text-decoration: none;
  z-index: 1001;
  border-radius: 4px;
}

.skip-link:focus {
  top: 6px;
}

/* ブログ一覧ページ用のヒーローセクション */
.hero-section {
  margin-top: 80px;
  background: var(--gradient-primary);
  color: var(--white);
  text-align: center;
  padding: 4rem 0;
}

.hero-content h1 {
  color: var(--white);
  margin-bottom: 1rem;
}

@media (max-width: 768px) {
  .article-meta {
    flex-direction: column;
    gap: 0.5rem;
  }
  
  .share-button-group {
    flex-direction: column;
    align-items: center;
  }
  
  .share-button {
    width: 200px;
  }
  
  .hero-image {
    max-width: 100%;
  }
  
  .article-content {
    padding: 0 1rem;
  }
}

@media (max-width: 480px) {
  .stats-container {
    grid-template-columns: 1fr;
  }
  
  .container {
    padding: 0 15px;
  }
}