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;
  width: 100%;
  max-width: 600px;
  height: 400px;
}

canvas {
  width: 100%;
  height: 100%;
  display: block;
}

.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;
}

/* content-area */
  .content-area {
    background: #1a1a2e;
    padding: 20px;
    border-radius: 10px;
    margin-top: 20px;
    box-shadow: 0 0 15px rgba(0, 255, 255, 0.3);
  }

/* Feedback Popup */
  .feedback-popup {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: #001f3f;
    padding: 20px;
    border-radius: 10px;
    box-shadow: 0 0 15px rgba(0, 255, 255, 0.5);
    z-index: 1000;
    width: 90%;
    max-width: 500px;
  }

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

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

  .close-button {
    background: #ff4444;
  }