body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background-color: #f5f7fa;
  color: #333;
  margin: 0;
  padding: 0;
}

#app {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 2rem;
  gap: 2rem;
}

#canvas-section {
  background-color: white;
  padding: 1.5rem;
  border-radius: 12px;
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.05);
  width: 600px;
}

h2 {
  margin-top: 0;
  font-size: 1.5rem;
}

canvas {
  border: 2px solid #ddd;
  border-radius: 8px;
  display: block;
  margin-top: 0rem;
  width: 100%;
  height: auto;
}

fieldset {
  border: 2px solid #ddd;
  border-radius: 8px;
  padding: 1rem;
  width: 100%;
  box-sizing: border-box;
}

legend {
  font-weight: bold;
  padding: 0 0.5rem;
}

ul {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

li {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
}

label {
  flex: 1;
  font-size: 14px;
}

input[type="range"] {
  flex: 0%;
  accent-color: #04776e;
}

input[type="number"] {
  flex: 1;
  max-width: 150px;
  padding: 0.4rem;
  border: 1px solid #ccc;
  border-radius: 6px;
}

.canvas-container {
  border: 2px solid #ddd;
  border-radius: 8px;
  margin-top: 1.5rem;
  position: relative;
  padding-top: 1.8rem;
  background-color: white;
}

.canvas-legend {
  position: absolute;
  top: 0;
  left: 1rem;
  transform: translateY(-50%);
  background-color: white;
  padding: 0 0.5rem;
  font-weight: bold;
  color: #333;
}

canvas {
  display: block;
  width: 100%;
  height: auto;
  border: none;
  /* remove old border */
}