* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Poppins', sans-serif;
}

.container {
    width: 100%;
    height: 100vh;
    background: #e3f9ff;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
}

.calculator {
    background: #3a4452;
    padding: 20px;
    border-radius: 10px;
    max-width: 100%;
}

.calculator form input {
    border: 0;
    outline: 0;
    width: 60px;
    height: 60px;
    border-radius: 10px;
    box-shadow: -8px -8px 15px rgba(255, 255, 255, 0.1), 5px 5px 15px rgba(0, 0, 0, 0.2);
    background: transparent;
    font-size: 20px;
    color: #fff;
    margin: 10px;
    cursor: pointer;
}

form .display {
    display: flex;
    justify-content: flex-end;
    margin: 20px 0;
}

form .display input {
    text-align: right;
    flex: 1;
    font-size: 45px;
    box-shadow: none;
}

form input.equal {
    width: 145px;
}

form input.operator {
    color: #33ffd8
}


.calculator form input:hover {
    background: rgba(255, 255, 255, 0.1);
    transform: translateY(-2px);
    box-shadow: -10px -10px 20px rgba(255, 255, 255, 0.15), 6px 6px 20px rgba(0, 0, 0, 0.3);
    transition: all 0.2s ease;
}

form input.operator:hover {
    background: rgba(51, 255, 216, 0.1);
    color: #4dffdd;
}

form input.equal:hover {
    background: rgba(51, 255, 216, 0.15);
    color: #4dffdd;
}


@media (max-width: 480px) {
    .calculator {
        padding: 15px;
    }

    .calculator form input {
        width: 50px;
        height: 50px;
        font-size: 18px;
        margin: 8px;
    }

    form .display input {
        font-size: 36px;
    }

    form input.equal {
        width: 124px;
    }
}

@media (max-width: 380px) {
    .calculator {
        padding: 12px;
    }

    .calculator form input {
        width: 45px;
        height: 45px;
        font-size: 16px;
        margin: 6px;
    }

    form .display input {
        font-size: 32px;
    }

    form input.equal {
        width: 108px;
    }
}

@media (max-width: 320px) {
    .calculator {
        padding: 10px;
    }

    .calculator form input {
        width: 40px;
        height: 40px;
        font-size: 14px;
        margin: 5px;
    }

    form .display input {
        font-size: 28px;
    }

    form input.equal {
        width: 95px;
    }
}