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

body {
    font-family: 'Inter', sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    color: #333;
    line-height: 1.6;
}

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

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

.logo {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 15px;
    margin-bottom: 10px;
}

.logo i {
    font-size: 2.5rem;
    color: #ffd700;
}

.logo h1 {
    font-size: 2.5rem;
    font-weight: 700;
    text-shadow: 0 2px 4px rgba(0,0,0,0.3);
}

.subtitle {
    font-size: 1.1rem;
    opacity: 0.9;
    font-weight: 300;
}

/* Main Content */
.main-content {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
}

.converter-card {
    background: white;
    border-radius: 20px;
    padding: 40px;
    box-shadow: 0 20px 60px rgba(0,0,0,0.1);
    width: 100%;
    max-width: 600px;
    transition: all 0.3s ease;
}

.converter-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 25px 80px rgba(0,0,0,0.15);
}

/* Upload Section */
.upload-area {
    border: 3px dashed #e0e6ed;
    border-radius: 15px;
    padding: 60px 40px;
    text-align: center;
    transition: all 0.3s ease;
    cursor: pointer;
    background: #fafbfc;
}

.upload-area:hover {
    border-color: #667eea;
    background: #f8f9ff;
}

.upload-area.dragover {
    border-color: #667eea;
    background: #f0f4ff;
    transform: scale(1.02);
}

.upload-icon i {
    font-size: 4rem;
    color: #667eea;
    margin-bottom: 20px;
    display: block;
}

.upload-area h3 {
    font-size: 1.5rem;
    margin-bottom: 10px;
    color: #2d3748;
    font-weight: 600;
}

.upload-area p {
    color: #718096;
    margin-bottom: 25px;
    font-size: 1rem;
}

.browse-btn {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    padding: 12px 30px;
    border-radius: 25px;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    display: inline-flex;
    align-items: center;
    gap: 10px;
}

.browse-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(102, 126, 234, 0.4);
}

/* File Info */
.file-info {
    margin: 30px 0;
}

.file-details {
    display: flex;
    align-items: center;
    background: #f8f9fa;
    padding: 20px;
    border-radius: 12px;
    border: 1px solid #e9ecef;
}

.file-icon i {
    font-size: 2.5rem;
    color: #dc3545;
    margin-right: 15px;
}

.file-meta {
    flex: 1;
}

.file-meta h4 {
    font-size: 1.1rem;
    font-weight: 600;
    color: #2d3748;
    margin-bottom: 5px;
}

.file-meta p {
    color: #718096;
    font-size: 0.9rem;
}

.remove-file {
    background: #ff6b6b;
    color: white;
    border: none;
    width: 35px;
    height: 35px;
    border-radius: 50%;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

.remove-file:hover {
    background: #ff5252;
    transform: scale(1.1);
}

/* Conversion Options */
.conversion-options {
    margin: 30px 0;
    padding: 25px;
    background: #f8f9ff;
    border-radius: 12px;
    border: 1px solid #e6f0ff;
}

.conversion-options h3 {
    font-size: 1.3rem;
    margin-bottom: 20px;
    color: #2d3748;
    font-weight: 600;
}

.options-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

.option-group {
    display: flex;
    flex-direction: column;
}

.option-group label {
    font-weight: 500;
    margin-bottom: 8px;
    color: #4a5568;
    font-size: 0.9rem;
}

.option-group select {
    padding: 10px 15px;
    border: 2px solid #e2e8f0;
    border-radius: 8px;
    font-size: 0.9rem;
    background: white;
    cursor: pointer;
    transition: all 0.3s ease;
}

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

/* Convert Section */
.convert-section {
    text-align: center;
    margin: 30px 0;
}

.convert-btn {
    background: linear-gradient(135deg, #48bb78 0%, #38a169 100%);
    color: white;
    border: none;
    padding: 15px 40px;
    border-radius: 25px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: inline-flex;
    align-items: center;
    gap: 12px;
}

.convert-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(72, 187, 120, 0.4);
}

.convert-btn:disabled {
    background: #cbd5e0;
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

/* Progress Section */
.progress-section {
    text-align: center;
    margin: 30px 0;
}

.progress-info h3 {
    font-size: 1.3rem;
    margin-bottom: 10px;
    color: #2d3748;
    font-weight: 600;
}

.progress-info p {
    color: #718096;
    margin-bottom: 25px;
}

.progress-bar {
    width: 100%;
    height: 8px;
    background: #e2e8f0;
    border-radius: 4px;
    overflow: hidden;
    margin-bottom: 15px;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, #667eea, #764ba2);
    width: 0%;
    transition: width 0.3s ease;
    border-radius: 4px;
}

.progress-percentage {
    font-size: 1.1rem;
    font-weight: 600;
    color: #667eea;
}

/* Success Section */
.success-section {
    text-align: center;
    margin: 30px 0;
}

.success-icon i {
    font-size: 4rem;
    color: #48bb78;
    margin-bottom: 20px;
    display: block;
}

.success-section h3 {
    font-size: 1.5rem;
    margin-bottom: 10px;
    color: #2d3748;
    font-weight: 600;
}

.success-section p {
    color: #718096;
    margin-bottom: 30px;
}

.download-actions {
    display: flex;
    gap: 15px;
    justify-content: center;
    flex-wrap: wrap;
}

.download-btn {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    padding: 12px 30px;
    border-radius: 25px;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    display: inline-flex;
    align-items: center;
    gap: 10px;
}

.download-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(102, 126, 234, 0.4);
}

.convert-another-btn {
    background: transparent;
    color: #667eea;
    border: 2px solid #667eea;
    padding: 12px 30px;
    border-radius: 25px;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    display: inline-flex;
    align-items: center;
    gap: 10px;
}

.convert-another-btn:hover {
    background: #667eea;
    color: white;
    transform: translateY(-2px);
}

/* Footer */
.footer {
    margin-top: 40px;
    text-align: center;
    color: white;
}

.features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 20px;
    margin-bottom: 30px;
}

.feature {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    padding: 20px;
    background: rgba(255,255,255,0.1);
    border-radius: 12px;
    backdrop-filter: blur(10px);
    transition: all 0.3s ease;
}

.feature:hover {
    background: rgba(255,255,255,0.2);
    transform: translateY(-3px);
}

.feature i {
    font-size: 1.5rem;
    color: #ffd700;
}

.feature span {
    font-size: 0.9rem;
    font-weight: 500;
}

.copyright {
    opacity: 0.8;
    font-size: 0.9rem;
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: 15px;
    }
    
    .converter-card {
        padding: 30px 20px;
    }
    
    .logo h1 {
        font-size: 2rem;
    }
    
    .upload-area {
        padding: 40px 20px;
    }
    
    .options-grid {
        grid-template-columns: 1fr;
    }
    
    .download-actions {
        flex-direction: column;
        align-items: center;
    }
    
    .features {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 480px) {
    .logo {
        flex-direction: column;
        gap: 10px;
    }
    
    .logo h1 {
        font-size: 1.8rem;
    }
    
    .features {
        grid-template-columns: 1fr;
    }
}

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

.converter-card > div {
    animation: fadeIn 0.5s ease-out;
}

/* Loading Animation */
@keyframes pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.5;
    }
}

.progress-section {
    animation: pulse 2s infinite;
}