body {
    background-color: #f2f2f2;
    font-family: Arial, sans-serif;
}
h1 {
    color: #333;
    text-align: center;
    margin-top: 50px;
}
#bonus-btn {
    font-size: 1em;
    padding: 10px 20px;
  }
#form {
    width: 80%;
    margin: auto;
    background-color: #fff;
    padding: 20px;
    border-radius: 5px;
    box-shadow: 0px 2px 5px rgba(0,0,0,0.3);
}
label {
    display: block;
    margin-bottom: 10px;
    color: #666;
}
input[type="number"] {
    padding: 10px;
    border: none;
    border-radius: 3px;
    background-color: #f2f2f2;
    color: #333;
    font-size: 16px;
    width: 100%;
    box-sizing: border-box;
}
input[type="number"]:focus {
    outline: none;
    border: 2px solid #333;
}
input[type="submit"] {
    display: block;
    margin-top: 20px;
    padding: 10px;
    border: none;
    border-radius: 3px;
    background-color: #333;
    color: #fff;
    font-size: 16px;
    cursor: pointer;
    width: 100%;
    box-sizing: border-box;
}
input[type="submit"]:hover {
    background-color: #555;
}
p#error {
    color: #f00;
    margin-top: 10px;
    font-size: 16px;
    text-align: center;
}
.result {
    color: #333;
    margin-top: 20px;
    font-size: 20px;
    text-align: center;
}
/* output section styles */

.output {
    display: flex;
    flex-direction: column;
    align-items: center;
    margin-top: 20px;
  }
  
  .output label {
    margin-bottom: 10px;
  }
  
  .output .result {
    display: flex;
    justify-content: center;
    align-items: center;
    font-weight: bold;
    font-size: 20px;
    color: #000000;
    height: 50px;
    min-width: 200px;
    margin: 10px;
    border: 1px solid #ccc;
    white-space: nowrap;
    background-color: #fff;
    padding: 20px;
    border-radius: 5px;
    box-shadow: 0px 2px 5px rgba(0,0,0,0.3);
  }