/* Series Navigation - Compact Design */
.series-navigation {
  background: var(--card-bg);
  border: 1px solid var(--main-border-color);
  border-radius: .5rem;
  padding: 0.75rem;
  margin: 1rem 0;
  box-shadow: var(--card-shadow);
}

.series-header h3 {
  margin: 0 0 0.5rem 0;
  color: var(--heading-color);
  font-size: 0.95rem;
  font-weight: 600;
  font-family: Lato, "Microsoft Yahei", sans-serif;
}

.series-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.series-item {
  display: flex;
  align-items: flex-start;
  padding: 0.35rem 0.5rem;
  margin: 0.15rem 0;
  background: transparent;
  border-radius: .375rem;
  transition: background 0.2s ease;
  gap: 0.5rem;
}

.series-item:hover {
  background: var(--card-hovor-bg);
}

.series-item.active {
  background: var(--sidebar-hover-bg);
  border-left: 2px solid var(--link-color);
  padding-left: calc(0.5rem - 2px);
}

.series-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 1.25rem;
  height: 1.25rem;
  background: var(--tag-bg, var(--btn-border-color));
  color: var(--text-muted-color);
  border-radius: 50%;
  font-size: 0.65rem;
  font-weight: 600;
  flex-shrink: 0;
  margin-top: 0.1rem;
}

.series-item.active .series-number {
  background: var(--link-color);
  color: white;
}

.series-content {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
  min-width: 0;
}

.series-date {
  color: var(--text-muted-color);
  font-size: 0.65rem;
  white-space: nowrap;
  font-weight: 500;
}

.series-title {
  color: var(--text-color);
  text-decoration: none;
  font-size: 0.75rem;
  line-height: 1.3;
  display: block;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.series-title:hover {
  color: var(--link-color);
  border-bottom: none;
}

.series-title.current {
  font-weight: 600;
  color: var(--link-color);
}

/* Hide Recently Updated and Trending Tags when series exists */
body:has(.series-navigation) .access {
  display: none;
}

/* Responsive design */
@media (max-width: 768px) {
  .series-navigation {
    padding: 0.75rem;
    margin: 0.75rem -0.5rem;
    border-radius: 0;
  }
}