body {
  margin: 0;
  font-family: 'Segoe UI', sans-serif;
  background: #f4f7fa;
  color: #333;
}

.container {
  max-width: 800px;
  margin: auto;
  padding: 20px;
  background: #fff;
  border-radius: 12px;
  box-shadow: 0 10px 20px rgba(0,0,0,0.1);
}

h1 {
  text-align: center;
  color: #2c3e50;
}

.tabs {
  display: flex;
  justify-content: center;
  margin: 20px 0;
}

.tab-button {
  padding: 10px 20px;
  margin: 0 5px;
  border: none;
  background: #e0e0e0;
  border-radius: 6px;
  cursor: pointer;
  transition: background 0.3s;
}

.tab-button.active {
  background: #007bff;
  color: white;
}

.tab-content {
  display: none;
  margin-top: 20px;
}

.tab-content.active {
  display: block;
}

label {
  display: block;
  margin-bottom: 10px;
  font-weight: 500;
}

input[type=number],
input[type=range] {
  width: 100%;
  padding: 8px;
  margin-top: 5px;
  box-sizing: border-box;
  border: 1px solid #ccc;
  border-radius: 6px;
}

canvas {
  margin-top: 20px;
  max-height: 300px;
}

button {
  margin-top: 20px;
  padding: 10px 15px;
  background: #28a745;
  border: none;
  color: white;
  border-radius: 6px;
  cursor: pointer;
  transition: background 0.3s;
}

button:hover {
  background: #218838;
}

.collapsible-content {
  display: none;
  margin-top: 10px;
  background: #f9f9f9;
  padding: 15px;
  border-left: 4px solid #007BFF;
  border-radius: 4px;
  font-size: 14px;
}

.toggle-btn {
  background-color: #007BFF;
  color: white;
  border: none;
  padding: 10px 15px;
  font-size: 14px;
  cursor: pointer;
  border-radius: 5px;
  margin-top: 10px;
}

.toggle-btn:hover {
  background-color: #0056b3;
}


@media (max-width: 600px) {
  .tabs {
    flex-direction: column;
  }

  .tab-button {
    margin: 5px 0;
  }
}