body {
  font-family: "Inter", sans-serif;
  background-color: #f0f2f5;
  display: flex;
  justify-content: center;
  align-items: flex-start;
  min-height: 100vh;
  padding: 20px;
}
.container {
  background-color: #ffffff;
  border-radius: 12px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
  padding: 32px;
  width: 100%;
  max-width: 960px;
}
.tab-button {
  padding: 12px 24px;
  border-radius: 8px 8px 0 0;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s ease-in-out;
  background-color: #e2e8f0; /* gray-200 */
  color: #4a5568; /* gray-700 */
}
.tab-button.active {
  background-color: #ffffff;
  color: #2b6cb0; /* blue-700 */
  box-shadow: 0 -2px 8px rgba(0, 0, 0, 0.05);
}
.tab-content {
  display: none;
  padding-top: 20px;
}
.tab-content.active {
  display: block;
}
.status-available {
  background-color: #d1fae5; /* green-100 */
  color: #065f46; /* green-800 */
}
.status-on-loan {
  background-color: #fee2e2; /* red-100 */
  color: #991b1b; /* red-800 */
}
.modal {
  display: none; /* Hidden by default */
  position: fixed; /* Stay in place */
  z-index: 1000; /* Sit on top */
  left: 0;
  top: 0;
  width: 100%; /* Full width */
  height: 100%; /* Full height */
  overflow: auto; /* Enable scroll if needed */
  background-color: rgba(0, 0, 0, 0.4); /* Black w/ opacity */
  justify-content: center;
  align-items: center;
}
.modal-content {
  background-color: #fefefe;
  margin: auto;
  padding: 24px;
  border-radius: 8px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
  width: 90%;
  max-width: 500px;
}
.close-button {
  color: #aaa;
  float: right;
  font-size: 28px;
  font-weight: bold;
}
.close-button:hover,
.close-button:focus {
  color: black;
  text-decoration: none;
  cursor: pointer;
}
.message-modal-content {
  background-color: #fefefe;
  margin: auto;
  padding: 24px;
  border-radius: 8px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
  width: 90%;
  max-width: 400px;
  text-align: center;
}
.message-modal-content button {
  margin-top: 20px;
  padding: 10px 20px;
  border-radius: 8px;
  cursor: pointer;
  transition: background-color 0.2s;
}
table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 20px;
}
th,
td {
  border: 1px solid #e2e8f0;
  padding: 12px;
  text-align: left;
}
th {
  background-color: #f8f8f8;
  font-weight: 600;
}
tr:nth-child(even) {
  background-color: #f0f2f5;
}
.sortable-header {
  cursor: pointer;
  position: relative;
}
.sortable-header:hover {
  background-color: #e2e8f0; /* gray-200 */
}
.sort-indicator {
  display: inline-block;
  width: 1em;
  height: 1em;
  margin-left: 5px;
  vertical-align: middle;
  transition: transform 0.2s ease-in-out;
}
.sort-indicator::after {
  content: "▲"; /* Default up arrow */
  font-size: 0.8em;
  color: #a0aec0; /* gray-400 */
  opacity: 0.5;
}
.sortable-header[data-sort-dir="asc"] .sort-indicator::after {
  content: "▲";
  opacity: 1;
  color: #2b6cb0; /* blue-700 */
}
.sortable-header[data-sort-dir="desc"] .sort-indicator::after {
  content: "▼";
  opacity: 1;
  color: #2b6cb0; /* blue-700 */
}