body {
  margin: 0;
  font-family: Arial, Helvetica, sans-serif;
  background: #f7f7f7;
  color: #222;
}

main {
  max-width: 1050px;
  margin: 0 auto;
  padding: 32px 18px 60px;
}

h1 {
  margin-bottom: 4px;
}

.subtitle {
  margin-top: 0;
  color: #555;
}

.card {
  background: #fff;
  border-radius: 14px;
  padding: 18px;
  margin: 18px 0;
  box-shadow: 0 4px 18px rgba(0,0,0,0.07);
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 14px;
}

label {
  display: block;
  font-weight: 600;
  margin-bottom: 6px;
}

textarea,
input {
  width: 100%;
  box-sizing: border-box;
  border: 1px solid #ccc;
  border-radius: 8px;
  padding: 9px;
  font-size: 15px;
}

button {
  border: none;
  border-radius: 10px;
  padding: 12px 18px;
  font-size: 16px;
  cursor: pointer;
  background: #222;
  color: white;
}

button:hover {
  opacity: 0.85;
}

.plot {
  min-height: 420px;
}

pre {
  white-space: pre-wrap;
  background: #f2f2f2;
  padding: 12px;
  border-radius: 8px;
}

code {
  background: #eee;
  padding: 2px 5px;
  border-radius: 4px;
}