* {
  box-sizing: border-box;
}
body {
  margin: 0;
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background: #f4f6f8;
  color: #333;
  display: flex;
  height: 100vh;
}
.sidebar {
  width: 250px;
  background-color: #2c3e50;
  color: white;
  padding: 20px;
  display: flex;
  flex-direction: column;
}
.sidebar h2 {
  margin-top: 0;
  margin-bottom: 30px;
  font-weight: 700;
  font-size: 24px;
}
.sidebar nav ul {
  list-style: none;
  padding: 0;
  margin: 0;
}
.sidebar nav ul li {
  margin-bottom: 15px;
  cursor: pointer;
  padding: 8px 12px;
  border-radius: 5px;
  transition: background-color 0.3s;
}
.sidebar nav ul li:hover,
.sidebar nav ul li.active {
  background-color: #34495e;
}
.main-content {
  flex: 1;
  display: flex;
  flex-direction: column;
  padding: 30px;
  overflow-y: auto;
}
.screen {
  max-width: 900px;
  margin: 0 auto;
}
.hidden {
  display: none;
}
h1, h2 {
  font-weight: 600;
}
input[type="text"], input[type="password"], input[type="date"], input[type="number"] {
  padding: 8px;
  margin-top: 5px;
  margin-bottom: 15px;
  border: 1px solid #ccc;
  border-radius: 4px;
  width: 100%;
  font-size: 16px;
}
button {
  cursor: pointer;
  background-color: #2980b9;
  border: none;
  color: white;
  padding: 10px 18px;
  font-size: 16px;
  border-radius: 5px;
  transition: background-color 0.3s;
}
button:hover {
  background-color: #1c5980;
}
.btn-logout {
  float: right;
  background-color: #e74c3c;
}
.btn-logout:hover {
  background-color: #c0392b;
}
.error {
  color: red;
  margin-top: 10px;
}
.message {
  margin-top: 10px;
  color: green;
}
#products-container {
  margin-bottom: 15px;
}
.product-row {
  display: flex;
  gap: 10px;
  margin-bottom: 10px;
}
.product-row input[type="text"] {
  flex: 2;
}
.product-row input[type="number"] {
  flex: 1;
}
.remove-row-btn {
  background-color: #e74c3c;
  border: none;
  color: white;
  font-weight: bold;
  font-size: 18px;
  border-radius: 4px;
  padding: 0 8px;
  cursor: pointer;
  height: 34px;
  align-self: center;
}
.remove-row-btn:hover {
  background-color: #c0392b;
}
table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 20px;
}
th, td {
  border: 1px solid #ddd;
  padding: 10px;
  text-align: left;
}
th {
  background-color: #2980b9;
  color: white;
}