.box {
    max-width: 500px;
    width: 90%;
}
.form-group {
    margin-bottom: 20px;
}
.form-group label {
    display: block;
    margin-bottom: 8px;
    font-size: 16px;
    color: #333;
}
.file-input {
    display: none;
}
.file-label {
    display: inline-block;
    padding: 12px 20px;
    background-color: #2196F3;
    color: white;
    border: none;
    border-radius: 10px;
    font-size: 16px;
    cursor: pointer;
    transition: background-color 0.3s ease;
}
.file-label:hover {
    background-color: #1976D2;
}
.file-name {
    margin-left: 10px;
    color: #666;
}
.expire-options {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
}
.expire-option {
    flex: 1;
    min-width: 80px;
}
.expire-option input[type="radio"] {
    display: none;
}
.expire-option label {
    display: block;
    padding: 10px;
    border: 2px solid #ddd;
    border-radius: 10px;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
}
.expire-option input[type="radio"]:checked + label {
    border-color: #2196F3;
    background-color: rgba(33, 150, 243, 0.1);
}
.btn {
    width: 100%;
    height: 50px;
    background-color: #4CAF50;
    color: white;
    border: none;
    border-radius: 10px;
    font-size: 18px;
    font-weight: bold;
    cursor: pointer;
    transition: background-color 0.3s ease;
}
.btn:hover {
    background-color: #45a049;
}
.btn:disabled {
    background-color: #cccccc;
    cursor: not-allowed;
}
.back-btn {
    width: 100%;
    height: 45px;
    margin-top: 15px;
    background-color: #9e9e9e;
    color: white;
    border: none;
    border-radius: 10px;
    font-size: 16px;
    font-weight: bold;
    cursor: pointer;
    transition: background-color 0.3s ease;
    text-decoration: none;
    display: block;
    text-align: center;
    line-height: 45px;
}
.back-btn:hover {
    background-color: #757575;
}
.error {
    color: #f44336;
    margin-bottom: 15px;
    text-align: center;
}
.success {
    color: #4CAF50;
    margin-bottom: 15px;
    text-align: center;
    padding: 15px;
    border: 2px solid #4CAF50;
    border-radius: 10px;
    background-color: rgba(76, 175, 80, 0.1);
}
.code-display {
    font-size: 24px;
    font-weight: bold;
    letter-spacing: 5px;
    color: #2196F3;
}
.progress-container {
    width: 100%;
    height: 20px;
    background-color: #f1f1f1;
    border-radius: 10px;
    overflow: hidden;
    margin-top: 10px;
}
.progress-bar {
    height: 100%;
    background-color: #2196F3;
    width: 0%;
    transition: width 0.3s ease;
}
.uploading-text {
    text-align: center;
    margin-top: 10px;
    color: #666;
}