:root {
  --color-primary: #4a90e2;
  --color-secondary: #50e3c2;
  --color-background: #f5f5f5;
  --color-text: #333;
  --color-error: #e94e77;
  --color-dark-bg: #333;
  --color-dark-text: #f5f5f5;
  --transition-duration: 0.3s;
}

@media (prefers-color-scheme: dark) {
  :root {
    --color-background: var(--color-dark-bg);
    --color-text: var(--color-dark-text);
  }
}

body {
  font-family: 'Arial', sans-serif;
  background-color: var(--color-background);
  color: var(--color-text);
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
}

.container {
  max-width: 600px;
  width: 100%;
  padding: 20px;
  background: #fff;
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
  border-radius: 8px;
}

h1 {
  font-size: 1.5rem;
  color: var(--color-primary);
  margin-bottom: 20px;
}

form {
  display: grid;
  gap: 15px;
}

input[type="text"],
input[type="number"],
select,
button {
  width: 100%;
  padding: 10px;
  border: 1px solid #ccc;
  border-radius: 4px;
  transition: border-color var(--transition-duration);
}

input[type="text"]:focus,
input[type="number"]:focus,
select:focus,
button:focus {
  border-color: var(--color-primary);
  outline: none;
}

input[type="text"]:hover,
input[type="number"]:hover,
select:hover {
  border-color: var(--color-secondary);
}

input[type="text"].error,
input[type="number"].error {
  border-color: var(--color-error);
}

button {
  background-color: var(--color-primary);
  color: #fff;
  border: none;
  cursor: pointer;
  transition: background-color var(--transition-duration);
}

button:hover {
  background-color: var(--color-secondary);
}

button:active {
  background-color: var(--color-primary);
  transform: scale(0.98);
}

button:disabled {
  background-color: #ccc;
  cursor: not-allowed;
}

.result {
  background: var(--color-secondary);
  color: #fff;
  padding: 15px;
  border-radius: 4px;
  text-align: center;
}

@media (max-width: 768px) {
  h1 {
    font-size: 1.25rem;
  }

  .container {
    padding: 15px;
  }
}

@media print {
  body {
    background-color: #fff;
    color: #000;
  }

  .container {
    box-shadow: none;
    border: 1px solid #ccc;
  }

  button {
    display: none;
  }
}

@supports not (display: grid) {
  form {
    display: block;
  }
}