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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f5f5f5;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 20px;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

header {
    text-align: center;
    margin-bottom: 40px;
    padding: 30px 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border-radius: 12px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

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

header p {
    font-size: 1.1rem;
    opacity: 0.9;
}

main {
    flex: 1;
    background: white;
    padding: 40px;
    border-radius: 12px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    margin-bottom: 20px;
}

.alert {
    padding: 16px 20px;
    margin-bottom: 25px;
    border-radius: 8px;
    border-left: 4px solid;
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 15px;
}

.alert-error {
    background-color: #fef2f2;
    border-color: #ef4444;
    color: #dc2626;
}

.alert-success {
    background-color: #f0fdf4;
    border-color: #22c55e;
    color: #16a34a;
}

.upload-form {
    max-width: 600px;
    margin: 0 auto;
}

.form-group {
    margin-bottom: 25px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: #374151;
    font-size: 0.95rem;
}

.form-group input[type="file"],
.form-group input[type="text"],
.form-group select {
    width: 100%;
    padding: 12px 16px;
    border: 2px solid #e5e7eb;
    border-radius: 8px;
    font-size: 1rem;
    transition: all 0.2s ease;
    background-color: #fff;
}

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

.form-group input[type="file"] {
    padding: 16px;
    border-style: dashed;
    background-color: #fafafa;
    cursor: pointer;
    transition: all 0.2s ease;
}

.form-group input[type="file"]:hover {
    background-color: #f0f9ff;
    border-color: #667eea;
}

.form-group small {
    display: block;
    margin-top: 6px;
    color: #6b7280;
    font-size: 0.85rem;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 14px 28px;
    font-size: 1rem;
    font-weight: 500;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    text-decoration: none;
    transition: all 0.2s ease;
    min-height: 48px;
    gap: 8px;
}

.btn-primary {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    width: 100%;
    margin-top: 10px;
}

.btn-primary:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.3);
}

.btn-primary:active {
    transform: translateY(0);
}

.btn-download {
    background-color: #059669;
    color: white;
    padding: 10px 20px;
    font-size: 0.9rem;
}

.btn-download:hover {
    background-color: #047857;
    transform: translateY(-1px);
    box-shadow: 0 2px 8px rgba(5, 150, 105, 0.3);
}

.btn-clear {
    background-color: #6b7280;
    color: white;
    padding: 10px 20px;
    font-size: 0.9rem;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.2s ease;
}

.btn-clear:hover {
    background-color: #4b5563;
    transform: translateY(-1px);
    box-shadow: 0 2px 8px rgba(107, 114, 128, 0.3);
}

.btn-loading {
    opacity: 0.7;
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none !important;
}

footer {
    text-align: center;
    padding: 20px 0;
    color: #6b7280;
    font-size: 0.9rem;
}

@media (max-width: 768px) {
    .container {
        padding: 15px;
    }

    header {
        padding: 20px 15px;
        margin-bottom: 25px;
    }

    header h1 {
        font-size: 2rem;
    }

    main {
        padding: 25px 20px;
    }

    .alert {
        flex-direction: column;
        align-items: flex-start;
        gap: 10px;
    }

    .btn-download {
        width: 100%;
        margin-top: 10px;
    }
}

@media (max-width: 480px) {
    header h1 {
        font-size: 1.75rem;
    }

    main {
        padding: 20px 15px;
    }

    .form-group {
        margin-bottom: 20px;
    }
}

.progress-bar {
    width: 100%;
    height: 6px;
    background-color: #e5e7eb;
    border-radius: 3px;
    overflow: hidden;
    margin: 15px 0;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, #667eea, #764ba2);
    width: 0%;
    transition: width 0.3s ease;
}

.file-info {
    background-color: #f8fafc;
    padding: 15px;
    border-radius: 8px;
    margin-top: 10px;
    border: 1px solid #e2e8f0;
}

.file-info h4 {
    margin-bottom: 8px;
    color: #374151;
}