body {
  font-family: Arial, Helvetica, sans-serif;
  background: linear-gradient(135deg, #f5f7fa, #e4e8ef);
  margin: 0;
  padding: 0;
}

.container {
  max-width: 750px;
  margin: 40px auto;
  background: #fff;
  padding: 30px;
  border-radius: 14px;
  box-shadow: 0 10px 25px rgba(0, 0, 0, 0.08);
}

h2 {
  text-align: center;
  margin-bottom: 20px;
}

label {
  font-weight: 600;
  margin-top: 10px;
  display: block;
}

input,
select {
  width: 100%;
  padding: 12px;
  margin-top: 6px;
  border-radius: 8px;
  border: 1px solid #ccc;
  font-size: 15px;
}

button {
  margin-top: 20px;
  width: 100%;
  padding: 14px;
  background: #111;
  color: #fff;
  border: none;
  border-radius: 8px;
  font-size: 16px;
  cursor: pointer;
  transition: 0.3s;
}

button:hover {
  background: #333;
}

.result-box {
  margin-top: 25px;
  background: #f7f8fb;
  padding: 20px;
  border-radius: 10px;
  display: none;
}

.result-box h3 {
  margin-top: 0;
}

.preset-buttons {
  display: flex;
  gap: 10px;
  margin-top: 10px;
}

.preset-buttons button {
  flex: 1;
  background: #0073ff;
}

.preset-buttons button:hover {
  background: #005fe0;
}