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

body {
    font-family: Arial, sans-serif;
    line-height: 1.6;
    background-color: #f4f4f4;
    color: #333;
}

.container {
    max-width: 800px;
    margin: 2rem auto;
    padding: 2rem;
    background-color: #fff;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

h1 {
    text-align: center;
    margin-bottom: 2rem;
    color: #2c3e50;
}

.tabs {
    display: flex;
    margin-bottom: 2rem;
    border-bottom: 2px solid #eee;
}

.tab-btn {
    padding: 1rem 2rem;
    border: none;
    background: none;
    cursor: pointer;
    font-size: 1rem;
    color: #666;
    transition: all 0.3s ease;
}

.tab-btn.active {
    color: #2c3e50;
    border-bottom: 2px solid #3498db;
    margin-bottom: -2px;
}

.tab-content {
    margin-top: 2rem;
}

.hidden {
    display: none;
}

.upload-form {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.input-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

label {
    font-weight: bold;
    color: #2c3e50;
}

input[type="file"],
input[type="url"],
select {
    padding: 0.8rem;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-size: 1rem;
}

.submit-btn {
    padding: 1rem;
    background-color: #3498db;
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 1rem;
    transition: background-color 0.3s ease;
}

.submit-btn:hover {
    background-color: #2980b9;
}

.progress {
    margin-top: 2rem;
}

.progress-bar {
    height: 20px;
    background-color: #eee;
    border-radius: 10px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background-color: #3498db;
    width: 0%;
    transition: width 0.3s ease;
}

.progress-text {
    text-align: center;
    margin-top: 0.5rem;
    color: #666;
}

.message {
    margin-top: 1rem;
    padding: 1rem;
    border-radius: 4px;
    text-align: center;
}

.message.error {
    background-color: #ffebee;
    color: #c62828;
}

.message.success {
    background-color: #e8f5e9;
    color: #2e7d32;
}

.warning-message {
    background-color: #fff3cd;
    color: #856404;
    padding: 1rem;
    margin-bottom: 1.5rem;
    border-radius: 4px;
    text-align: center;
    font-weight: bold;
}