/* Reset and base styles */
* {
    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 */
.container {
    max-width: 1200px;
    margin: 0 auto;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-radius: 20px;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
    overflow: hidden;
}

/* Header */
.header {
    background: linear-gradient(135deg, #667eea, #764ba2);
    color: white;
    padding: 30px;
    text-align: center;
}

.header h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
}

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

/* Main content */
.main-content {
    padding: 30px;
}

/* Drop zone */
.drop-zone {
    border: 3px dashed #667eea;
    border-radius: 15px;
    padding: 60px 20px;
    text-align: center;
    margin-bottom: 30px;
    transition: all 0.3s ease;
    background: linear-gradient(45deg, rgba(102, 126, 234, 0.05), rgba(118, 75, 162, 0.05));
    position: relative;
    overflow: hidden;
}

.drop-zone::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(102, 126, 234, 0.1) 0%, transparent 70%);
    opacity: 0;
    transition: opacity 0.3s ease;
}

.drop-zone:hover::before {
    opacity: 1;
}

.drop-zone.dragover {
    border-color: #764ba2;
    background: linear-gradient(45deg, rgba(102, 126, 234, 0.1), rgba(118, 75, 162, 0.1));
    transform: scale(1.02);
}

.drop-zone h3 {
    font-size: 1.5rem;
    color: #667eea;
    margin-bottom: 15px;
}

.drop-zone p {
    color: #666;
    font-size: 1.1rem;
}

/* File list */
.file-list {
    background: #f8f9ff;
    border-radius: 15px;
    padding: 20px;
    margin-bottom: 20px;
    max-height: 400px;
    overflow-y: auto;
}

.file-list h3 {
    color: #667eea;
    margin-bottom: 15px;
    font-size: 1.3rem;
}

.file-item {
    display: flex;
    align-items: center;
    padding: 12px 15px;
    margin-bottom: 8px;
    background: white;
    border-radius: 10px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
    transition: all 0.3s ease;
    cursor: pointer;
}

.file-item:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 20px rgba(102, 126, 234, 0.15);
}

.file-item input[type="checkbox"] {
    margin-right: 12px;
    transform: scale(1.2);
    accent-color: #667eea;
}

.file-item .file-path {
    flex-grow: 1;
    font-family: 'Courier New', monospace;
    color: #333;
    font-size: 0.95rem;
}

.file-item .file-size {
    color: #666;
    font-size: 0.85rem;
    margin-left: 10px;
}

/* Controls */
.controls {
    display: flex;
    gap: 15px;
    margin-bottom: 20px;
    flex-wrap: wrap;
}

.btn {
    padding: 12px 24px;
    border: none;
    border-radius: 10px;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 600;
    transition: all 0.3s ease;
    text-decoration: none;
    display: inline-block;
    text-align: center;
}

.btn-primary {
    background: linear-gradient(135deg, #667eea, #764ba2);
    color: white;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(102, 126, 234, 0.4);
}

.btn-secondary {
    background: #f1f3f4;
    color: #333;
    border: 2px solid #e0e0e0;
}

.btn-secondary:hover {
    background: #e8eaed;
    border-color: #667eea;
}

/* Output section */
.output-section {
    background: #f8f9ff;
    border-radius: 15px;
    padding: 20px;
}

.output-section h3 {
    color: #667eea;
    margin-bottom: 15px;
    font-size: 1.3rem;
}

.output-textarea {
    width: 100%;
    min-height: 300px;
    padding: 15px;
    border: 2px solid #e0e0e0;
    border-radius: 10px;
    font-family: 'Courier New', monospace;
    font-size: 0.9rem;
    background: white;
    resize: vertical;
    transition: border-color 0.3s ease;
}

.output-textarea:focus {
    outline: none;
    border-color: #667eea;
}

/* Stats */
.stats {
    display: flex;
    gap: 20px;
    margin-bottom: 20px;
    flex-wrap: wrap;
}

.stat-item {
    background: white;
    padding: 15px 20px;
    border-radius: 10px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
    text-align: center;
    flex: 1;
    min-width: 120px;
}

.stat-number {
    font-size: 1.5rem;
    font-weight: bold;
    color: #667eea;
}

.stat-label {
    font-size: 0.9rem;
    color: #666;
    margin-top: 5px;
}

/* Hidden class */
.hidden {
    display: none;
}

/* Animations */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

.fade-in {
    animation: fadeIn 0.5s ease-out;
}

/* Responsive design */
@media (max-width: 768px) {
    .container {
        margin: 10px;
        border-radius: 10px;
    }

    .header {
        padding: 20px;
    }

    .header h1 {
        font-size: 2rem;
    }

    .main-content {
        padding: 20px;
    }

    .drop-zone {
        padding: 40px 15px;
    }

    .controls {
        gap: 10px;
    }

    .btn {
        padding: 10px 16px;
        font-size: 0.9rem;
    }

    .file-list {
        max-height: 300px;
    }
}

@media (max-width: 480px) {
    .stats {
        flex-direction: column;
    }

    .stat-item {
        min-width: 100%;
    }

    .file-item .file-path {
        font-size: 0.85rem;
    }

    .file-item .file-size {
        font-size: 0.8rem;
    }
}