body {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    background: #f2c250;
    font-family: Arial, sans-serif;
}
main {
    background: #57dae8;
    padding: 20px;
    border-radius: 10px;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
    text-align: center;
    min-width: 400px;
}
input {
    width: 95%;
    padding: 10px;
    margin-bottom: 10px;
    font-size: 1.2em;
    text-align: right;
    border: none;
    border-radius: 5px;
    background: #ffdde1;
}
.buttons {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 5px;
}
.row {
    display: flex;
    justify-content: center;
    gap: 5px;
}
.num-btn {
    background: #ffcc99;
}
.num-btn:hover {
    background: #ffb366;
}
button {
    width: 50px;
    padding: 10px;
    font-size: 1.1em;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    background: #ffb3b3;
    transition: 0.3s;
}
button:hover {
    background: #ff9999;
}