body {
  background: linear-gradient(135deg, #111, #1a1a2e);
  color: #fff;
  font-family: 'Arial', sans-serif;
  text-align: center;
  margin: 0;
  padding: 0;
}

.container {
  max-width: 900px;
  margin: auto;
  padding: 20px;
}

h1 {
  font-size: 2.5rem;
  text-shadow: 0 0 10px cyan;
}

.canvas-container {
  margin: 20px auto;
  background: #001f3f;
  border-radius: 10px;
  box-shadow: 0 0 15px rgba(0, 255, 255, 0.3);
  overflow: hidden;
  padding: 20px;
}

.button {
  background: #007bff;
  color: white;
  padding: 10px 15px;
  border: none;
  border-radius: 8px;
  margin: 10px;
  cursor: pointer;
  font-size: 1rem;
  transition: 0.3s;
}

.button:hover {
  background: #0056b3;
}

.button-grid {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
}

.feedback-popup {
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  background: #222;
  padding: 20px;
  border-radius: 10px;
  box-shadow: 0 0 15px rgba(0, 255, 255, 0.3);
  z-index: 1000;
}

.feedback-popup.hidden {
  display: none;
}

.feedback-popup textarea {
  width: 100%;
  margin-bottom: 10px;
  border-radius: 5px;
  padding: 10px;
  resize: none;
}