body {
  margin: 0;
  font-family: "Segoe UI", sans-serif;
  display: flex;
  min-height: 100vh;
  background-color: #f6f6f6;
}
.sidebar {
  width: 220px;
  background-color: #1e1e2f;
  color: #fff;
  padding: 20px;
  flex-shrink: 0;
}
.sidebar h2 {
  font-size: 20px;
  margin-top: 0;
  text-align: center;
}
.sidebar ul {
  list-style: none;
  padding: 0;
}
.sidebar li {
  margin: 12px 0;
}
.sidebar a, .sidebar select {
  color: white;
  text-decoration: none;
  font-size: 16px;
  background: transparent;
  border: none;
  cursor: pointer;
  width: 100%;
}
.sidebar select {
  background-color: #1e1e2f;
  color: #fff;
  font-size: 16px;
}
.main-content {
  flex: 1;
  padding: 20px;
  overflow-y: auto;
  background-color: #fff;
}
.hidden {
  display: none;
}
input, select, button {
  padding: 8px;
  margin: 6px 0;
  font-size: 15px;
}
button {
  cursor: pointer;
}
.error {
  color: red;
}
table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 10px;
}
th, td {
  border: 1px solid #ccc;
  padding: 6px;
  text-align: left;
}
.requests-table {
  margin-top: 20px;
}
.supplier-section {
  border: 1px solid #ccc;
  padding: 10px;
  margin-bottom: 15px;
  background: #f9f9f9;
}
@media (max-width: 768px) {
  body {
    flex-direction: column;
  }
  .sidebar {
    width: 100%;
    text-align: center;
  }
  .main-content {
    padding: 10px;
  }
}