.certification-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 60px 20px;
}

.certification-header {
  text-align: center;
  margin-bottom: 50px;
}

.certification-header h1 {
  font-size: 2.5rem;
  font-weight: 700;
  color: #333;
  margin-bottom: 10px;
}

.certification-header p {
  font-size: 1.1rem;
  color: #666;
}

.certification-tabs {
  border-bottom: 2px solid #e0e0e0;
  margin-bottom: 40px;
}

.certification-tabs .nav-link {
  border: none;
  color: #666;
  font-weight: 600;
  padding: 15px 30px;
  margin-right: 10px;
  border-radius: 0;
  position: relative;
}

.certification-tabs .nav-link.active {
  color: #000;
  background: none;
  border-bottom: 3px solid #000;
}

.certification-tabs .nav-link:hover {
  color: #333;
  background: none;
}

.certification-timeline {
  max-width: 800px;
  margin: 0 auto;
}

.timeline-year {
  font-size: 2rem;
  font-weight: 700;
  color: #333;
  margin: 40px 0 25px 0;
  padding-bottom: 15px;
  border-bottom: 3px solid #f0f0f0;
}

.timeline-year:first-child {
  margin-top: 0;
}

.certification-item {
  background: white;
  border: 2px solid #e0e0e0;
  border-radius: 12px;
  padding: 35px;
  margin-bottom: 20px;
  transition: all 0.3s ease;
  position: relative;
  display: flex;
  align-items: flex-start;
  gap: 25px;
}

.certification-item:hover {
  box-shadow: 0 6px 20px rgba(0,0,0,0.15);
  transform: translateY(-3px);
  border-color: #ccc;
}

.certification-image {
  flex-shrink: 0;
  width: 120px;
  height: 160px;
  border-radius: 8px;
  overflow: hidden;
  border: 1px solid #ddd;
  cursor: pointer;
  transition: transform 0.3s ease;
}

.certification-image:hover {
  transform: scale(1.05);
}

.certification-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.certification-content {
  flex: 1;
  min-width: 0;
}

.certification-date {
  color: #666;
  font-size: 1.3rem;
  font-weight: 600;
  margin-bottom: 12px;
}

.certification-title {
  font-size: 2rem;
  font-weight: 700;
  color: #333;
  margin-bottom: 12px;
  line-height: 1.4;
}

.certification-organization {
  color: #666;
  font-size: 1.4rem;
  font-weight: 500;
  margin-bottom: 0;
}

.certification-category {
  position: absolute;
  top: -10px;
  right: 25px;
  background: #333;
  color: white;
  padding: 8px 16px;
  border-radius: 16px;
  font-size: 1.2rem;
  font-weight: 700;
}

.certification-category.patent {
  background: #999;
}

/* Image Modal Styles */
.modal-backdrop {
  background-color: rgba(0,0,0,0.8);
}

.modal-dialog {
  max-width: 90%;
  margin: 30px auto;
}

.modal-content {
  border: none;
  border-radius: 12px;
}

.modal-header {
  border-bottom: 1px solid #e0e0e0;
  padding: 20px 25px;
}

.modal-title {
  font-size: 1.2rem;
  font-weight: 700;
  color: #333;
}

.modal-body {
  padding: 25px;
  text-align: center;
}

.modal-image {
  max-width: 100%;
  max-height: 70vh;
  border-radius: 8px;
  box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}

@media (max-width: 768px) {
  .certification-tabs .nav-link {
    padding: 15px 25px;
    font-size: 1rem;
    font-weight: 700;
  }

  .certification-header h1 {
    font-size: 2.2rem;
  }

  .certification-header p {
    font-size: 1.2rem;
  }

  .certification-item {
    padding: 25px 20px;
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: 20px;
  }

  .certification-image {
    width: 100px;
    height: 130px;
  }

  .certification-content {
    width: 100%;
  }

  .timeline-year {
    font-size: 1.7rem;
  }

  .certification-title {
    font-size: 1.25rem;
  }

  .certification-date {
    font-size: 1rem;
  }

  .certification-organization {
    font-size: 1rem;
  }

  .certification-category {
    font-size: 0.85rem;
    padding: 6px 14px;
    top: -8px;
    right: 20px;
  }

  .modal-dialog {
    margin: 15px;
    max-width: calc(100% - 30px);
  }

  .modal-header,
  .modal-body {
    padding: 15px 20px;
  }

  .navbar-brand img {
    max-height: 30px;
  }
}