:root {
  --bg-color: #f4f4f4;
  --text-color: #333;
  --card-color: #fff;
  --primary-color: #007bff;
  --secondary-color: #6c757d;
}

body.dark-mode {
  --bg-color: #121212;
  --text-color: #f4f4f4;
  --card-color: #1e1e1e;
  --primary-color: #66b2ff;
  --secondary-color: #999;
}

body {
  background-color: var(--bg-color);
  color: var(--text-color);
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  margin: 0;
  padding: 20px;
  transition: background-color 0.3s, color 0.3s;
}

.container {
  max-width: 400px;
  margin: 0 auto;
  background-color: var(--card-color);
  padding: 20px;
  border-radius: 12px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

h1 {
  text-align: center;
  margin-bottom: 20px;
}

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

input,
select {
  width: 100%;
  padding: 10px;
  margin-top: 5px;
  border: 1px solid #ccc;
  border-radius: 6px;
  background-color: var(--bg-color);
  color: var(--text-color);
  transition: background-color 0.3s, color 0.3s;
}

button {
  width: 100%;
  padding: 12px;
  margin-top: 15px;
  font-size: 16px;
  border: none;
  border-radius: 8px;
  background-color: var(--primary-color);
  color: #fff;
  cursor: pointer;
  transition: background-color 0.3s;
}

button:hover {
  background-color: #0056b3;
}

#swapBtn {
  background-color: var(--secondary-color);
  margin-top: 10px;
}

#swapBtn:hover {
  background-color: #555;
}

#refreshRatesBtn {
  background-color: #28a745;
  margin-top: 10px;
}

#refreshRatesBtn:hover {
  background-color: #1e7e34;
}

#toggleTheme {
  background-color: #444;
  margin-top: 15px;
}

#toggleTheme:hover {
  background-color: #222;
}

#result {
  margin-top: 20px;
  font-weight: bold;
  font-size: 1.2rem;
  text-align: center;
}

#lastUpdated {
  margin-top: 5px;
  font-size: 0.85rem;
  color: var(--secondary-color);
  text-align: center;
}


input,
select,
button {
  width: 100%;
  padding: 10px;
  margin-bottom: 10px;
  box-sizing: border-box;
  font-size: 1rem;
}