* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: Arial, sans-serif;
    background-color: #f7f9fc;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
}

.container {
    background: white;
    border-radius: 10px;
    box-shadow: 0 8px 20px rgba(0,0,0,0.1);
    max-width: 600px;
    padding: 30px;
    width: 100%;
}

.container h1 {
    color: #333;
    text-align: center;
    margin-bottom: 25px;
}

.file-input, .key-input {
    margin-bottom: 20px;
}

label {
    font-weight: bold;
    color: #555;
    display: block;
    margin-bottom: 10px;
}

input[type=file], textarea {
    width: 100%;
    border: 1px solid #ddd;
    border-radius: 5px;
    padding: 10px;
    font-size: 1rem;
}

button {
    background: #007bff;
    color: white;
    border: none;
    border-radius: 5px;
    padding: 12px;
    width: 100%;
    font-size: 1rem;
    cursor: pointer;
}

button:hover {
    background: #0056b3;
}

.message {
    text-align: center;
    margin-top: 15px;
    color: green;
}