body {
    display: flex;
    flex-direction:column;
    justify-content: center;
    align-items: center;
    height: 100vh;
    background-color: #f0f0f0;
    font-family: Arial, sans-serif;
    margin:0;
}

.calculator {
    background-color: #fff;
    border-radius: 10px;
    box-shadow: 0 0 10px rgba(0,0,0,0.1);
    padding:20px;
    width: 280px;
}

h2{
    margin-top:0px;
    margin-bottom:0px;
}

.display {
    margin-bottom: 10px;
}

.history-container {
    position:relative;
    display: flex;
    flex-direction: column;
}

.history-label {
    font-size: 14px;
    color: #333;
    margin-bottom: 5px;
}

#display,
#history {
    width: 92%;
    height: 30px;
    font-size: 18px;
    text-align: right;
    padding: 10px;
    border: 1px solid #ccc;
    outline:none;
}

#history {
    background-color: #ccc;
    border-radius: 5px 5px 0px 0px;
    border-bottom:none;
}

#display {
    border-radius: 0px 0px 5px 5px;
}

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

.btn,
.btn-zero,
.btn-equal,
.btn-f {
    height:50px;
    font-size: 18px;
    color:#fff;
    border:none;
    border-radius:5px;
    cursor:pointer;
    outline:none;
}

.btn {
    background-color: #007bff;
}

.btn-f {
    background-color: #0056b3;
}

.btn-zero {
    background-color: #007bff;
    grid-column: span 2;
}

.btn-equal {
    background-color: #b3003c;
    grid-column: span 2;
}

.btn:hover,
.btn-zero:hover {
    background-color: #0056b3;
}

.btn-f:hover {
    background-color: #007bff;
}

.btn-equal:hover {
    background-color: #ad2e58;
}

footer{
    margin-top:20px;
    text-align:center;
}

footer p{
    font-size:14px;
    margin:5px 0;
}

footer a{
    color:#007bff;
    text-decoration:none;
}
footer a:hover{
    text-decoration:underline;
}
/* Media queries para responsividade */

@media (max-width: 400px){
    .calculator{
        width:90%;
    }

    #display,
    #history{
        font-size:16px;
    }

    .btn,
    .btn-zero,
    .btn-equal,
    .btn-f{
        height:45px;
        font-size:16px;
    }
}