body {
  font-family: Arial, sans-serif;
  background: #f9f9f9;
  margin: 0;
  padding: 0;
}
.container {
  max-width: 800px;
  margin: 2rem auto;
  padding: 2rem;
  background: #fff;
  border-radius: 10px;
  box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}
.pdf-counter {
  background: #e8f4fd;
  color: #2c5282;
  padding: 1rem;
  margin-bottom: 2rem;
  border-radius: 8px;
  border: 2px solid #bee3f8;
  text-align: center;
  font-weight: bold;
  font-size: 1.1em;
}
.entry-card {
  background: #f8f8f8;
  padding: 2rem;
  margin-bottom: 2rem;
  border-radius: 8px;
  border-left: 4px solid #2c3e50;
  box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}
.entry-title {
  font-size: 1.4rem;
  font-weight: bold;
  color: #2c3e50;
  margin-bottom: 0.5rem;
}
.entry-author {
  color: #34495e;
  font-style: italic;
  margin-bottom: 0.5rem;
}
.entry-date {
  color: #7f8c8d;
  margin-bottom: 1rem;
}
.entry-doi {
  background: #3498db;
  color: white;
  padding: 0.5rem 1rem;
  border-radius: 4px;
  text-decoration: none;
  display: inline-block;
  transition: background 0.3s;
}
.entry-doi:hover {
  background: #2980b9;
  color: white;
  text-decoration: none;
}
.upload-area {
  border: 2px dashed #bdc3c7;
  border-radius: 8px;
  padding: 2rem;
  text-align: center;
  background: white;
  margin: 2rem 0;
  transition: all 0.3s;
  cursor: pointer;
}
.upload-area:hover, .upload-area.dragover {
  border-color: #3498db;
  background: #ecf0f1;
}
.upload-area input[type="file"] {
  display: none;
}
.upload-text {
  color: #7f8c8d;
  font-size: 1.1rem;
}
.file-info {
  background: #e8f5e8;
  border: 1px solid #27ae60;
  border-radius: 4px;
  padding: 1rem;
  margin-top: 1rem;
  color: #27ae60;
}
.buttons-container {
  text-align: center;
  margin-top: 2rem;
}
.btn {
  background: #3498db;
  color: white;
  border: none;
  padding: 0.8rem 2rem;
  border-radius: 5px;
  cursor: pointer;
  font-size: 1rem;
  margin: 0 0.5rem;
  transition: all 0.3s;
}
.btn:hover {
  background: #2980b9;
  transform: translateY(-1px);
}
.btn:disabled {
  background: #bdc3c7;
  cursor: not-allowed;
  transform: none;
}
.btn-report {
  background: #e74c3c;
}
.btn-report:hover {
  background: #c0392b;
}
.btn-primary {
  background: #27ae60;
  font-size: 1.2rem;
  padding: 1rem 2.5rem;
  font-weight: bold;
}
.btn-primary:hover {
  background: #229954;
}
.btn-secondary {
  background: #f39c12;
}
.btn-secondary:hover {
  background: #e67e22;
}
.btn-large-upload {
  background: #9b59b6;
  text-decoration: none;
  display: inline-block;
}
.btn-large-upload:hover {
  background: #8e44ad;
}
.loading {
  display: inline-block;
  width: 20px;
  height: 20px;
  border: 3px solid #f3f3f3;
  border-top: 3px solid #3498db;
  border-radius: 50%;
  animation: spin 1s linear infinite;
  margin-right: 0.5rem;
}
@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}
.error {
  background: #ffe6e6;
  border: 1px solid #e74c3c;
  color: #e74c3c;
  padding: 1rem;
  border-radius: 4px;
  margin: 1rem 0;
}
.success {
  background: #e8f5e8;
  border: 1px solid #27ae60;
  color: #27ae60;
  padding: 1rem;
  border-radius: 4px;
  margin: 1rem 0;
}
.hidden {
  display: none;
}
.bibkey {
  background: #f8f9fa;
  padding: 0.3rem 0.6rem;
  border-radius: 3px;
  font-family: monospace;
  color: #6c757d;
  margin-left: 0.5rem;
}