/* Background */
body, html {
    margin: 0;
    padding: 0;
    height: 100%;
    font-family: 'Poppins', sans-serif; /* Font modern */
}

.background {
    background: linear-gradient(135deg, #66a6ff, #89f7fe);
    height: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
}

/* Calculator Container */
.calculator-container {
    background: linear-gradient(145deg, #ffffff, #e6e6e6); /* Gradien lembut */
    border-radius: 20px;
    padding: 25px;
    width: 350px;
    text-align: center;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
    transition: transform 0.3s ease;
}

.calculator-container:hover {
    transform: translateY(-5px); /* Efek hover */
}

/* Title */
h1 {
    font-size: 26px;
    color: #333;
    margin-bottom: 10px;
    text-shadow: 0px 2px 4px rgba(0, 0, 0, 0.1);
}

h2 {
    font-size: 18px;
    color: #555;
    margin-top: 0;
}

/* Display */
#display {
    width: 100%;
    padding: 15px;
    font-size: 24px;
    font-family: 'Roboto Mono', monospace; /* Font seperti layar kalkulator */
    border: 2px solid #ddd;
    border-radius: 15px;
    margin-bottom: 20px;
    background: rgba(255, 255, 255, 0.8); /* Transparan */
    text-align: right;
    outline: none;
    box-sizing: border-box;
    color: #333;
}

/* Buttons */
.buttons {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 10px;
}

button {
    padding: 15px;
    font-size: 20px;
    border: none;
    border-radius: 12px;
    cursor: pointer;
    transition: all 0.3s ease;
    background: linear-gradient(145deg, #4caf50, #3e8e41);
    color: white;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

button.operation {
    background: linear-gradient(145deg, #ffa726, #f57c00); /* Warna operasi */
}

button:hover {
    transform: translateY(-2px);
}

button:active {
    transform: scale(0.95);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
}

button.equals {
    grid-column: span 4;
    background: linear-gradient(145deg, #2196f3, #1e88e5);
}

button.equals:hover {
    background: linear-gradient(145deg, #1976d2, #1565c0);
}

/* Responsive Design */
@media (max-width: 400px) {
    .calculator-container {
        width: 90%;
    }
}