/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    color: #333;
    line-height: 1.6;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

/* Header Styles */
.header {
    text-align: center;
    padding: 40px 20px;
    color: white;
}

.title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 10px;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.2);
}

.subtitle {
    font-size: 1.1rem;
    opacity: 0.95;
    font-weight: 300;
}

/* Main Content */
.main-content {
    background: white;
    border-radius: 16px;
    padding: 40px;
    box-shadow: 0 10px 40px rgba(0,0,0,0.15);
    margin-bottom: 30px;
}

/* Upload Section */
.upload-section {
    margin-bottom: 40px;
}

.upload-area {
    border: 3px dashed #667eea;
    border-radius: 12px;
    padding: 60px 20px;
    text-align: center;
    transition: all 0.3s ease;
    background: #f8f9ff;
    cursor: pointer;
}

.upload-area:hover,
.upload-area.drag-over {
    background: #eff1ff;
    border-color: #764ba2;
    transform: translateY(-2px);
}

.upload-icon {
    color: #667eea;
    margin-bottom: 20px;
}

.upload-text {
    font-size: 1.3rem;
    color: #333;
    margin-bottom: 10px;
    font-weight: 500;
}

.upload-subtext {
    color: #666;
    margin: 15px 0;
    font-size: 0.95rem;
}

.upload-btn {
    display: inline-block;
    background: #667eea;
    color: white;
    padding: 12px 32px;
    border-radius: 8px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 1rem;
}

.upload-btn:hover {
    background: #5568d3;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.4);
}

.file-info {
    margin-top: 15px;
    color: #888;
    font-size: 0.9rem;
}

/* Preview Section */
.preview-section {
    margin-top: 40px;
}

.preview-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}

.preview-header h2 {
    font-size: 1.5rem;
    color: #333;
}

.btn-clear {
    background: #ff4757;
    color: white;
    border: none;
    padding: 8px 20px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.9rem;
    font-weight: 600;
    transition: all 0.3s ease;
}

.btn-clear:hover {
    background: #ee5a6f;
    transform: translateY(-1px);
}

/* Preview Grid */
.preview-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
    gap: 15px;
    margin-bottom: 30px;
}

.preview-item {
    position: relative;
    border-radius: 8px;
    overflow: hidden;
    background: #f5f5f5;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
    transition: transform 0.3s ease;
}

.preview-item:hover {
    transform: translateY(-4px);
    box-shadow: 0 4px 16px rgba(0,0,0,0.15);
}

.preview-img {
    width: 100%;
    height: 150px;
    object-fit: cover;
    display: block;
}

.preview-remove {
    position: absolute;
    top: 5px;
    right: 5px;
    background: rgba(255, 71, 87, 0.9);
    color: white;
    border: none;
    width: 28px;
    height: 28px;
    border-radius: 50%;
    cursor: pointer;
    font-size: 1.2rem;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
    font-weight: bold;
}

.preview-remove:hover {
    background: #ff4757;
    transform: scale(1.1);
}

/* Conversion Options */
.conversion-options {
    margin: 30px 0;
}

.label {
    display: block;
    margin-bottom: 8px;
    color: #555;
    font-weight: 600;
    font-size: 0.95rem;
}

.input-name {
    width: 100%;
    padding: 12px 16px;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    font-size: 1rem;
    transition: all 0.3s ease;
}

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

/* Convert Button */
.btn-convert {
    width: 100%;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    padding: 16px;
    border-radius: 8px;
    font-size: 1.1rem;
    font-weight: 700;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
}

.btn-convert:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(102, 126, 234, 0.4);
}

.btn-convert:disabled {
    opacity: 0.7;
    cursor: not-allowed;
}

/* Loader */
.loader {
    width: 20px;
    height: 20px;
    border: 3px solid rgba(255,255,255,0.3);
    border-top-color: white;
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* Info Section */
.info-section {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 20px;
    margin-top: 40px;
}

.info-card {
    text-align: center;
    padding: 30px 20px;
    background: #f8f9ff;
    border-radius: 12px;
    transition: all 0.3s ease;
}

.info-card:hover {
    background: #eff1ff;
    transform: translateY(-4px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.08);
}

.info-icon {
    color: #667eea;
    margin-bottom: 15px;
}

.info-card h3 {
    font-size: 1.2rem;
    color: #333;
    margin-bottom: 10px;
    font-weight: 600;
}

.info-card p {
    color: #666;
    font-size: 0.95rem;
    line-height: 1.6;
}

/* Footer */
.footer {
    text-align: center;
    color: white;
    padding: 20px;
    font-size: 0.9rem;
    opacity: 0.9;
}

/* Responsive Design */
@media (max-width: 768px) {
    .title {
        font-size: 2rem;
    }
    
    .main-content {
        padding: 25px 20px;
    }
    
    .upload-area {
        padding: 40px 15px;
    }
    
    .preview-grid {
        grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
        gap: 10px;
    }
    
    .preview-img {
        height: 120px;
    }
    
    .info-section {
        grid-template-columns: 1fr;
        gap: 15px;
    }
    
    .preview-header {
        flex-direction: column;
        gap: 15px;
        align-items: stretch;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 10px;
    }
    
    .header {
        padding: 30px 15px;
    }
    
    .title {
        font-size: 1.6rem;
    }
    
    .subtitle {
        font-size: 0.95rem;
    }
    
    .main-content {
        padding: 20px 15px;
        border-radius: 12px;
    }
}