body {
  margin: 0;
  padding: 0;
  font-family: 'Segoe UI', sans-serif;
  background-color: #121212;
  color: #f0f0f0;
}
.container {
  padding: 30px 5%;
  max-width: 800px;
  margin: auto;
}
.login-form,
.panel {
  background-color: #1e1e1e;
  padding: 25px;
  border-radius: 8px;
  box-shadow: 0 0 10px rgba(0,0,0,0.5);
}
input[type="text"],
input[type="number"],
input[type="password"] {
  width: 100%;
  padding: 10px;
  margin: 6px 0 16px;
  border: none;
  border-radius: 4px;
  background-color: #2c2c2c;
  color: #fff;
}
label {
  font-weight: bold;
}
button {
  background-color: #4caf50;
  color: white;
  border: none;
  padding: 10px 20px;
  margin-top: 10px;
  border-radius: 4px;
  cursor: pointer;
  font-size: 16px;
}
button:hover {
  background-color: #45a049;
}
.logout-btn {
  background-color: #f44336;
  float: right;
}
.hidden {
  display: none;
}
.section-heading {
  margin-top: 30px;
  margin-bottom: 10px;
  border-bottom: 1px solid #555;
  padding-bottom: 5px;
}
.top-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.popup {
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  padding: 15px 25px;
  background-color: #333;
  color: #fff;
  border-radius: 6px;
  box-shadow: 0 0 12px rgba(0, 0, 0, 0.4);
  font-size: 16px;
  z-index: 9999;
  opacity: 0;
  transition: opacity 0.3s ease;
  max-width: 80%;
  text-align: center;
}
.popup.success {
  background-color: #4caf50;
}
.popup.error {
  background-color: #f44336;
}
.popup.show {
  opacity: 1;
}
@media (max-width: 600px) {
  .container {
    padding: 20px 3%;
  }
  button {
    width: 100%;
  }
}