.roof-calculator-card {
  max-width: 520px;
  margin: 30px auto;
  padding: 25px;
  background: linear-gradient(135deg, #f5faff, #ffffff);
  border-radius: 18px;
  box-shadow: 0 10px 30px rgba(0,0,0,0.1);
  font-family: system-ui, sans-serif;
}

.roof-calculator-card h1 {
  text-align: center;
  font-size: 1.6rem;
}

.roof-calculator-card label {
  display: block;
  margin-top: 15px;
  font-weight: 600;
}

.roof-calculator-card input,
.roof-calculator-card select {
  width: 100%;
  padding: 10px;
  margin-top: 6px;
  border-radius: 10px;
  border: 1px solid #ccc;
  font-size: 1rem;
}

.roof-calculator-card button {
  width: 100%;
  margin-top: 20px;
  padding: 12px;
  border-radius: 12px;
  border: none;
  background: #2563eb;
  color: white;
  font-size: 1.1rem;
  cursor: pointer;
}

.roof-calculator-card button:hover {
  background: #1e40af;
}

.result-box {
  margin-top: 20px;
  padding: 15px;
  border-radius: 12px;
  background: #f0f9ff;
}

@media (max-width: 600px) {
  .roof-calculator-card {
    margin: 15px;
    padding: 20px;
  }
}