body {
    background-color: #f8f9fa;
    font-family: 'Arial', sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
}
.container {
    text-align: center;
    padding: 40px;
    border-radius: 15px;
    background: #ffffff;
    box-shadow: 0 4px 15px rgba(0, 123, 255, 0.2);
    width: 350px;
}
.logo {
    font-size: 50px;
    color: #007bff;
    margin-bottom: 15px;
}
h1 {
    font-size: 2rem;
    color: #007bff;
    margin-bottom: 15px;
}
label {
    display: block;
    font-weight: bold;
    margin: 10px 0 5px;
}
input {
    width: 100%;
    padding: 10px;
    border: 1px solid #ccc;
    border-radius: 5px;
    font-size: 1rem;
}
button {
    width: 100%;
    padding: 10px;
    background-color: #007bff;
    color: #fff;
    border: none;
    border-radius: 5px;
    font-size: 1rem;
    cursor: pointer;
    margin-top: 15px;
    transition: background-color 0.3s;
}
button:hover {
    background-color: #0056b3;
}
.status {
    font-size: 1.2rem;
    color: #007bff;
    margin-top: 20px;
}
.rfid-icon {
    font-size: 3rem;
    color: black;
    animation: pulse 1.5s infinite;
}
@keyframes pulse {
    0% { transform: scale(1); }
    50% { transform: scale(1.2); }
    100% { transform: scale(1); }
}
.preview {
    margin-top: 10px;
    text-align: center;
    display: none;
}
.preview img {
    max-width: 100%;
    max-height: 200px;
    border: 1px solid #ddd;
    border-radius: 4px;
    padding: 5px;
}
.message {
    margin: 10px 0;
    padding: 10px;
    border-radius: 5px;
    font-size: 14px;
}
.message.success {
    background-color: #d4edda;
    color: #155724;
    border: 1px solid #c3e6cb;
}
.message.error {
    background-color: #f8d7da;
    color: #721c24;
    border: 1px solid #f5c6cb;
}