.nav-tabs {
  border-bottom: 2px solid #e9ecef;
  margin-bottom: 2rem;
  display: flex;
  justify-content: center;
}

.nav-tabs .nav-link {
  border: none;
  color: #6c757d;
  font-weight: 600;
  font-size: 1.1rem;
  padding: 0.75rem 2rem;
  margin: 0 0.75rem;
  position: relative;
  transition: all 0.3s ease;
  background: transparent;
}

.nav-tabs .nav-link:hover {
  color: var(--secondary-color, #0056b3);
  background-color: transparent;
  border-color: transparent;
}

.nav-tabs .nav-link::after {
  content: '';
  position: absolute;
  width: 0;
  height: 3px;
  bottom: 0;
  left: 50%;
  background-color: var(--secondary-color, #0056b3);
  transition: all 0.3s ease;
  transform: translateX(-50%);
}

.nav-tabs .nav-link:hover::after {
  width: 30%;
}

.nav-tabs .nav-link.active {
  color: var(--secondary-color, #0056b3);
  background-color: transparent;
  border: none;
}

.nav-tabs .nav-link.active::after {
  width: 70%;
}

.tab-pane {
  transition: all 0.3s ease-in-out;
  position: relative;
}

.tab-pane.fade {
  opacity: 0;
  transform: translateY(10px);
}

.tab-pane.fade.show.active {
  opacity: 1;
  transform: translateY(0);
}

/* Animación para los elementos dentro de las pestañas */
.tab-pane .fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}

.tab-pane.show.active .fade-in.active {
  opacity: 1;
  transform: translateY(0);
}

.publication-authors {
  color: var(--secondary-color);
  font-weight: 500;
}

.publication-details {
  color: var(--text-color);
  font-size: 0.9rem;
}

.year-group h4 {
  color: var(--primary-color);
  margin: 2rem 0 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--light-gray);
  display: inline-block;
  margin-right: 10px;
  cursor: pointer;
  transition: color 0.2s ease;
}

.year-group h4:hover {
  color: var(--secondary-color, #0056b3);
}

.year-heading::after {
  content: '';
  display: inline-block;
  width: 0;
  height: 0;
  margin-left: 8px;
  vertical-align: middle;
  transition: transform 0.2s;
}

.year-group .toggle-btn {
  background-color: #f8f9fa;
  border: 1px solid #dee2e6;
  border-radius: 50%;
  width: 28px;
  height: 28px;
  padding: 0;
  font-size: 0.8rem;
  color: #495057;
  cursor: pointer;
  transition: all 0.2s;
  display: flex;
  align-items: center;
  justify-content: center;
}

.year-group .toggle-btn:hover {
  background-color: #e9ecef;
  border-color: #ced4da;
  color: #212529;
}

.patent-card {
  background: var(--white);
  border-radius: 8px;
  padding: 1.5rem;
  margin-bottom: 1.5rem;
  box-shadow: var(--box-shadow);
  transition: var(--transition);
}

.patent-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 10px 20px rgba(0, 0, 0, 0.15);
}

.patent-header {
  font-size: 1.3rem;
  color: var(--primary-color);
  margin-bottom: 1.2rem;
  border-bottom: 2px solid var(--light-gray);
  padding-bottom: 0.8rem;
}

.btn-toggle-abstract {
  color: var(--secondary-color);
  text-decoration: none;
  display: inline-block;
  margin-top: 1rem;
}

.btn-toggle-abstract:hover {
  color: var(--accent-color);
}

.patent-abstract {
  background-color: var(--light-gray);
  padding: 1rem;
  border-radius: 8px;
}