body {
  margin: 0;
  padding: 20px;
  font-family: 'Segoe UI', sans-serif;
  background: #e0e5ec;
  display: flex;
  justify-content: center;
  align-items: flex-start;
  min-height: 100vh;
}

.calculator {
  max-width: 700px;
  width: 100%;
  background: #e0e5ec;
  padding: 40px;
  border-radius: 20px;
  box-shadow: 10px 10px 30px #c2c8d0, -10px -10px 30px #ffffff;
}

h2 {
  text-align: center;
  margin-bottom: 20px;
  color: #333;
}

h2 small {
  display: block;
  font-size: 14px;
  color: #666;
}

label {
  font-weight: bold;
  margin-bottom: 5px;
  display: block;
  color: #333;
}

input,
select {
  width: 100%;
  padding: 12px;
  margin-bottom: 20px;
  border: none;
  border-radius: 12px;
  background: #e0e5ec;
  box-shadow: inset 4px 4px 6px #c8ccd1, inset -4px -4px 6px #f0f5fa;
  font-size: 1em;
  outline: none;
  transition: 0.3s;
}

input:focus,
select:focus {
  box-shadow: inset 2px 2px 5px #bec4cb, inset -2px -2px 5px #f0f5fa;
}

button {
  padding: 12px 24px;
  background: #e0e5ec;
  color: #333;
  border: none;
  border-radius: 12px;
  cursor: pointer;
  font-weight: bold;
  box-shadow: 6px 6px 10px #c2c8d0, -6px -6px 10px #ffffff;
  transition: background 0.3s;
  margin-right: 10px;
}

button:hover {
  background: #d6dce4;
}

.output {
  margin-top: 30px;
  padding: 20px;
  border-radius: 12px;
  background: #e0e5ec;
  box-shadow: inset 4px 4px 6px #c8ccd1, inset -4px -4px 6px #f0f5fa;
  font-size: 1.1em;
  color: #333;
}

.success {
  color: green;
  text-align: center;
  margin-top: 15px;
  font-weight: bold;
}