body {
    font-family: Arial, sans-serif;
    background: linear-gradient(to bottom, #1e3a8a, #000000); 
    color: white;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
}

.calculator {
    background: #1e293b; 
    padding: 20px;
    border-radius: 10px;
    box-shadow: 0 8px 15px rgba(0, 0, 0, 0.2);
    width: 350px;
}

.calculator h1 {
    text-align: center;
    margin-bottom: 20px;
    color: #3b82f6; 
}

.calculator input {
    width: 100%;
    padding: 10px;
    margin-bottom: 15px;
    border: 2px solid #334155; 
    border-radius: 5px;
    background: #f1f5f9; 
    color: #1e293b; 
    font-size: 16px;
}

.calculator .buttons {
    display: flex;
    justify-content: space-between;
    gap: 10px;
}

.calculator button {
    flex: 1;
    padding: 10px;
    font-size: 18px;
    font-weight: bold;
    color: white;
    background: #2563eb; 
    border: none;
    border-radius: 5px;
    cursor: pointer;
    transition: background 0.3s ease, transform 0.2s ease;
}

.calculator button:hover {
    background: #1d4ed8; 
    transform: scale(1.05); 
}

.calculator .result {
    margin-top: 20px;
    padding: 10px;
    text-align: center;
    background: #2563eb; 
    border-radius: 5px;
    font-size: 18px;
    font-weight: bold;
    color: white;
}