*{
    font-family: Poppins, Arial, sans-serif;
}

body {
    max-width: 500px;
    text-align: center;
    margin: 50px auto;
    background: #f4f4f4;
}
.container {
    background: white;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 0 10px rgba(0,0,0,0.1);
}
input {
    width: 50%;
    min-width: 140px;
    padding: 5px;
    font-size: 14px;
    margin: 5px 0;
    text-align: center;
}
button {
    padding: 10px 20px;
    font-size: 16px;
    cursor: pointer;
    margin: 5px;
}
.preset-buttons {
    margin: 10px 0;
}