body {
  font-family: 'Segoe UI', sans-serif;
  background: #f2f2f2;
  padding: 30px;
}
.app {
  background: #fff;
  padding: 25px;
  border-radius: 12px;
  box-shadow: 0 2px 10px rgba(0,0,0,0.1);
  max-width: 600px;
  margin: auto;
}
h1 {
  text-align: center;
  color: #222;
}
form label {
  display: block;
  margin: 10px 0;
  font-weight: 500;
}
input {
  width: 100px;
  padding: 4px;
  margin-left: 10px;
}
button {
  margin-top: 15px;
  padding: 8px 20px;
  background: #4CAF50;
  color: white;
  border: none;
  border-radius: 8px;
  cursor: pointer;
}
.results {
  margin-top: 30px;
  background: #e9fce9;
  padding: 20px;
  border-radius: 10px;
}
.info-box {
  margin-bottom: 20px;
  background: #d4eafd;
  padding: 15px;
  border-radius: 10px;
}
.error {
  color: red;
  font-weight: bold;
  margin-top: 10px;
}