:root {
  --bg-color: #f0f2f5;
  --card-color: #ffffff;
  --primary: #4a90e2;
  --primary-dark: #356ac3;
  --text-color: #333;
  --accent: #e3ecf8;
}

body {
  font-family: 'Segoe UI', sans-serif;
  background: var(--bg-color);
  margin: 0;
  padding: 0;
  color: var(--text-color);
}

.container {
  max-width: 600px;
  margin: 40px auto;
  background: var(--card-color);
  padding: 30px;
  border-radius: 15px;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

h1, h3 {
  text-align: center;
  margin-bottom: 20px;
}

.balance h3 {
  background: var(--primary);
  color: white;
  padding: 15px;
  border-radius: 10px;
  text-align: center;
  margin: 0 0 20px;
}

form {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

input, select {
  padding: 12px;
  font-size: 1rem;
  border: 1px solid #ccc;
  border-radius: 8px;
  transition: border-color 0.2s;
}

input:focus, select:focus {
  border-color: var(--primary);
  outline: none;
}

button {
  padding: 12px;
  font-size: 1rem;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  background: var(--primary);
  color: white;
  transition: background 0.2s;
}

button:hover {
  background: var(--primary-dark);
}

ul {
  list-style: none;
  padding: 0;
}

li {
  padding: 12px;
  background: var(--accent);
  margin: 8px 0;
  border-radius: 8px;
}

.buttons {
  display: flex;
  justify-content: space-between;
  margin-top: 25px;
}