* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

/* Define new color variables */
:root {
  --main-bg-color: #1a1a2e; /* Dark blue-gray */
  --section-bg-color: #f0f0f5; /* Light grayish white */
  --accent-color: #3a86ff; /* Bright blue */
  --btn-hover-gradient: linear-gradient(#82b1ff, #3a86ff); /* Light to bright blue */
  --btn-gradient: linear-gradient(#8ecae6, #219ebc); /* Light to medium blue */
}

body {
  background-color: var(--main-bg-color);
  font-family: 'Arial', sans-serif;
  color: #ffffff; 
  line-height: 1.6;
}

.start-screen, .checkpoint-screen {
  background-color: var(--section-bg-color);
  border-radius: 30px;
  padding: 20px;
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  width: 90%;
  max-width: 700px;
  box-shadow: 0 8px 16px rgba(0, 0, 0, 0.2);
  text-align: center;
}

.start-screen {
  padding-bottom: 5px;
}

.main-title, .instructions {
  color: #1a1a2e; 
}

.main-title {
  font-size: 2rem;
  margin-bottom: 10px;
}

.instructions {
  font-size: 1.2rem;
  margin: 15px 0;
  line-height: 2rem;
}

.btn {
  display: inline-block;
  cursor: pointer;
  padding: 10px 20px;
  font-size: 1rem;
  font-weight: bold;
  color: #ffffff; /* White text for contrast */
  background-color: var(--accent-color); 
  background-image: var(--btn-gradient); 
  border: 3px solid var(--accent-color);
  border-radius: 25px;
  transition: background 0.3s ease;
}

.btn:hover {
  background-image: var(--btn-hover-gradient);
}

.btn-container {
  display: flex;
  justify-content: center;
  gap: 20px;
  margin-top: 20px;
}

.checkpoint-screen {
  display: none;
  max-width: 300px;
  padding: 10px;
  border-radius: 20px;
  color: #1a1a2e;
}

#canvas {
  display: none;
}

@media (min-width: 768px) {
  .start-screen {
    width: 60%;
  }

  .checkpoint-screen {
    width: 40%;
  }
}