.section-title {
  border-left: none;
  padding-left: 1rem;
  margin-bottom: 1.5rem;
  display: inline-flex;
  align-items: center;
  background: #f8f9fa;
  padding: 0.75rem 1.5rem;
  border-radius: 8px;
  white-space: nowrap;
  min-width: fit-content;
}

.section-title .category-icon {
  font-size: 1.25rem;
  margin-right: 0.75rem;
  flex-shrink: 0;
}

/* Font Awesomeアイコンのafter要素を完全に削除 */
.fas::after,
.far::after,
.fab::after,
.fa::after,
i::after,
.category-icon::after,
[class^="fa-"]::after,
[class*=" fa-"]::after,
[class*="fa"]::after {
  content: none !important;
  display: none !important;
  border: none !important;
  margin: 0 !important;
  padding: 0 !important;
  width: 0 !important;
  height: 0 !important;
  position: static !important;
}

.note-card {
  border-radius: 10px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
  margin-bottom: 1.5rem;
  transition: all 0.3s ease;
  border: 1px solid rgba(0,0,0,0.125);
  overflow: hidden;
}

.note-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}

.note-card .card-header {
  background: linear-gradient(to right, #f8f9fa, #ffffff);
  border-bottom: 2px solid #e9ecef;
  padding: 1rem;
}

.note-card .card-body {
  padding: 1.5rem;
  background: #ffffff;
}

.novel-list {
  list-style: none;
  padding-left: 0;
  margin-bottom: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.novel-list.vertical {
  flex-direction: column;
  gap: 1rem;
}

.novel-list li {
  margin: 0;
}

.novel-list.vertical li {
  margin-bottom: 0.5rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid #e9ecef;
}

.novel-list.vertical li:last-child {
  margin-bottom: 0;
  padding-bottom: 0;
  border-bottom: none;
}

.novel-list a {
  color: #212529;
  text-decoration: none;
  padding: 0.5rem 1rem;
  border-radius: 5px;
  background: #f8f9fa;
  display: inline-block;
  transition: all 0.2s ease;
}

.novel-list.vertical a {
  display: block;
  padding: 0.75rem;
  border-radius: 8px;
}

.novel-list a:hover {
  background: #e9ecef;
  color: #007bff;
  transform: translateY(-2px);
}

.novel-list span {
  display: block;
  font-size: 0.875rem;
  color: #6c757d;
  margin-top: 0.5rem;
}

.section-description {
  color: #6c757d;
  margin-bottom: 1rem;
  font-size: 0.95rem;
}

.col-md-9 {
  min-height: 150vh;
  padding-bottom: 8rem;
}

#sidebar {
  background: #ffffff;
  padding: 1.5rem;
  border-radius: 12px;
  margin-bottom: 1.5rem;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
  position: sticky;
  top: 1rem;
  max-height: calc(100vh - 2rem);
  overflow-y: auto;
}

#sidebar .nav-link {
  padding: 0.75rem 1rem;
  color: #495057;
  border-radius: 8px;
  transition: all 0.2s ease;
  margin-bottom: 0.5rem;
  text-decoration: none;
}

#sidebar .nav-link:hover {
  background: #f8f9fa;
  color: #e67e22 !important;
  padding-left: 1.25rem;
}

#sidebar .nav-link.active {
  background: #e7f1ff;
  color: #212529;
  font-weight: 500;
}

.section-wrapper {
  scroll-margin-top: 2rem;
  min-height: 200px;
  margin-bottom: 2rem;
}

.section-wrapper:last-child {
  margin-bottom: 8rem;
}

.illust-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 1.5rem;
  margin-top: 1.5rem;
}

.illust-item {
  position: relative;
  aspect-ratio: 1;
  overflow: hidden;
  border-radius: 12px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
  transition: all 0.3s ease;
}

.illust-item:hover {
  transform: scale(1.02);
  box-shadow: 0 4px 12px rgba(0,0,0,0.2);
}

.illust-item img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.3s ease;
}

.illust-item:hover img {
  transform: scale(1.1);
}

@media (max-width: 768px) {
  #sidebar {
    position: static;
    margin-bottom: 2rem;
  }

  .section-title {
    font-size: 1.25rem;
    padding: 0.75rem 1rem;
  }

  .note-card {
    margin-bottom: 1rem;
  }
}