* {
  box-sizing: border-box;
}

body {
  margin: 0;
  padding: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Helvetica Neue", "Segoe UI", "Noto Sans JP", sans-serif;
  line-height: 1.8;
  color: #333;
  background-color: #fafafa;
}

a {
  color: #2e7d32;
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

.container {
  max-width: 960px;
  margin: 0 auto;
  padding: 0 16px;
}

/* Header */
.header {
  background-color: #fff;
  border-bottom: 1px solid #e0e0e0;
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-inner {
  max-width: 960px;
  margin: 0 auto;
  padding: 16px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 12px;
}

.site-title {
  margin: 0;
  font-size: 1.25rem;
  font-weight: 700;
}

.site-title a {
  color: #333;
  text-decoration: none;
}

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

.nav-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-list a {
  display: block;
  padding: 6px 12px;
  font-size: 0.875rem;
  font-weight: 500;
  color: #555;
  border-radius: 4px;
  white-space: nowrap;
}

.nav-list a:hover {
  color: #2e7d32;
  background-color: #e8f5e9;
  text-decoration: none;
}

/* Hero */
.hero {
  padding: 60px 16px;
  background-color: #fff;
  border-bottom: 1px solid #e0e0e0;
  text-align: center;
}

.hero-catch {
  margin: 0 0 16px;
  font-size: 1.75rem;
  font-weight: 700;
  line-height: 1.4;
  color: #333;
}

.hero-desc {
  margin: 0 auto 32px;
  max-width: 640px;
  font-size: 1.05rem;
  color: #555;
}

.hero-cta {
  display: inline-block;
  padding: 16px 40px;
  font-size: 1.1rem;
  font-weight: 600;
  color: #fff;
  background-color: #2e7d32;
  border-radius: 6px;
  text-decoration: none;
  transition: background-color 0.2s;
}

.hero-cta:hover {
  background-color: #1b5e20;
  text-decoration: none;
}

/* Sections */
.section-title {
  margin: 0 0 32px;
  font-size: 1.5rem;
  font-weight: 700;
  line-height: 1.4;
  text-align: center;
}

/* Categories */
.categories {
  padding: 60px 16px;
  background-color: #fafafa;
}

.category-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
}

.category-card {
  padding: 28px 24px;
  background-color: #fff;
  border: 1px solid #e0e0e0;
  border-radius: 8px;
  transition: box-shadow 0.2s, transform 0.2s;
}

.category-card:hover {
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
  transform: translateY(-2px);
}

.category-title {
  margin: 0 0 12px;
  font-size: 1.15rem;
  font-weight: 700;
  color: #333;
}

.category-desc {
  margin: 0;
  font-size: 0.95rem;
  color: #555;
  line-height: 1.7;
}

/* Latest Posts */
.latest {
  padding: 60px 16px;
  background-color: #fff;
}

.post-card {
  max-width: 720px;
  margin: 0 auto;
  padding: 28px 24px;
  background-color: #fafafa;
  border: 1px solid #e0e0e0;
  border-radius: 8px;
}

.post-title {
  margin: 0 0 12px;
  font-size: 1.25rem;
  font-weight: 700;
  line-height: 1.4;
}

.post-title a {
  color: #333;
}

.post-title a:hover {
  color: #2e7d32;
  text-decoration: none;
}

.post-excerpt {
  margin: 0 0 16px;
  font-size: 0.95rem;
  color: #555;
  line-height: 1.7;
}

.post-link {
  display: inline-block;
  font-size: 0.95rem;
  font-weight: 600;
  color: #2e7d32;
}

.post-link:hover {
  text-decoration: underline;
}

/* Course */
.course {
  padding: 60px 16px;
  background-color: #fafafa;
}

.course-box {
  max-width: 640px;
  margin: 0 auto;
  padding: 40px 24px;
  background-color: #e8f5e9;
  border-radius: 8px;
  text-align: center;
}

.course-title {
  margin: 0 0 16px;
  font-size: 1.5rem;
  font-weight: 700;
  line-height: 1.4;
  color: #333;
}

.course-desc {
  margin: 0 0 24px;
  font-size: 1rem;
  color: #555;
  line-height: 1.7;
}

.course-cta {
  display: inline-block;
  padding: 16px 40px;
  font-size: 1.1rem;
  font-weight: 600;
  color: #fff;
  background-color: #2e7d32;
  border-radius: 6px;
  text-decoration: none;
  transition: background-color 0.2s;
}

.course-cta:hover {
  background-color: #1b5e20;
  text-decoration: none;
}

.course-note {
  margin: 16px 0 0;
  font-size: 0.8rem;
  color: #666;
}

/* Footer */
.footer {
  padding: 32px 16px;
  background-color: #fff;
  border-top: 1px solid #e0e0e0;
}

.footer-copyright {
  margin: 0 0 12px;
  font-size: 0.875rem;
  color: #888;
  text-align: center;
}

.footer-nav-list {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 16px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.footer-nav-list a {
  font-size: 0.875rem;
  color: #888;
}

.footer-nav-list a:hover {
  color: #2e7d32;
  text-decoration: underline;
}

/* Responsive */
@media (max-width: 375px) {
  .hero-catch {
    font-size: 1.5rem;
  }

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

  .hero-cta {
    padding: 14px 28px;
    font-size: 1rem;
  }

  .section-title {
    font-size: 1.3rem;
  }

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

  .course-title {
    font-size: 1.3rem;
  }

  .course-cta {
    padding: 14px 28px;
    font-size: 1rem;
  }
}

@media (max-width: 480px) {
  .header-inner {
    flex-direction: column;
    align-items: stretch;
  }

  .nav-list {
    justify-content: center;
  }
}