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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 20px;
}

.container {
    max-width: 900px;
    margin: 0 auto;
    background: white;
    border-radius: 15px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.3);
    overflow: hidden;
}

.header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 40px;
    text-align: center;
}

.header h1 {
    font-size: 2.5em;
    margin-bottom: 10px;
    font-weight: 600;
}

.header p {
    font-size: 1.2em;
    opacity: 0.9;
}

.info-section, .warning {
    margin: 30px;
    padding: 20px;
    border-radius: 10px;
}

.info-section {
    background: #e8f5e8;
    border-left: 5px solid #4caf50;
}

.warning {
    background: #fff3cd;
    border-left: 5px solid #ffc107;
}

.info-section h3, .warning h3 {
    color: #333;
    margin-bottom: 15px;
}

.info-section ol, .warning ul {
    line-height: 1.6;
    padding-left: 20px;
}

.upload-form {
    padding: 30px;
}

.file-input-group {
    display: grid;
    gap: 20px;
    margin-bottom: 30px;
}

.file-input {
    background: #f8f9fa;
    padding: 20px;
    border-radius: 10px;
    border: 2px solid #e9ecef;
    transition: border-color 0.3s ease;
}

.file-input:hover {
    border-color: #667eea;
}

.file-input label {
    display: block;
    font-weight: 600;
    color: #333;
    margin-bottom: 10px;
    font-size: 1.1em;
}

.file-input input[type="file"] {
    width: 100%;
    padding: 12px;
    border: 2px solid #ddd;
    border-radius: 8px;
    font-size: 16px;
    transition: border-color 0.3s ease;
}

.file-input input[type="file"]:focus {
    border-color: #667eea;
    outline: none;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.file-info {
    margin-top: 8px;
    font-size: 0.9em;
    color: #666;
}

.submit-btn {
    width: 100%;
    background: linear-gradient(135deg, #4caf50 0%, #45a049 100%);
    color: white;
    padding: 18px 30px;
    border: none;
    border-radius: 10px;
    font-size: 1.2em;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.submit-btn:hover {
    background: linear-gradient(135deg, #45a049 0%, #4caf50 100%);
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(76, 175, 80, 0.4);
}

.submit-btn:disabled {
    background: #bdc3c7;
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

.loading {
    display: none;
    text-align: center;
    padding: 30px;
}

.spinner {
    border: 4px solid #f3f3f3;
    border-top: 4px solid #667eea;
    border-radius: 50%;
    width: 50px;
    height: 50px;
    animation: spin 1s linear infinite;
    margin: 0 auto 20px;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

.result {
    padding: 20px 30px;
}

.success, .error {
    padding: 15px;
    border-radius: 8px;
    margin: 10px 0;
    display: none;
}

.success {
    background: #d4edda;
    border: 1px solid #c3e6cb;
    color: #155724;
}

.error {
    background: #f8d7da;
    border: 1px solid #f5c6cb;
    color: #721c24;
}

@media (max-width: 768px) {
    .container {
        margin: 10px;
    }
    
    .header {
        padding: 30px 20px;
    }
    
    .header h1 {
        font-size: 2em;
    }
    
    .info-section, .warning, .upload-form, .result {
        margin: 20px;
        padding: 20px;
    }
}