:root {
    --primary: #667eea;
    --secondary: #764ba2;
    --accent: #f093fb;
    --success: #4ade80;
    --error: #f87171;
    --warning: #fbbf24;
    --dark: #1f2937;
    --light: #f8fafc;
    --border: #e5e7eb;
    --shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 20px 40px rgba(0, 0, 0, 0.15);
}

.utitlies {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    min-height: 100vh;
    padding: 1rem;
    display: flex;
    align-items: center;
    justify-content: center;
}

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
}

.converter-card {
    background: white;
    border-radius: 20px;
    box-shadow: var(--shadow-lg);
    overflow: hidden;
    animation: slideUp 0.6s ease;
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.header {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: white;
    padding: 2rem;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="grain" width="100" height="100" patternUnits="userSpaceOnUse"><circle cx="25" cy="25" r="1" fill="rgba(255,255,255,0.1)"/><circle cx="75" cy="75" r="1" fill="rgba(255,255,255,0.1)"/></pattern></defs><rect width="100" height="100" fill="url(%23grain)"/></svg>');
    opacity: 0.1;
}

.header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    position: relative;
    z-index: 1;
}

.header p {
    font-size: 1.1rem;
    opacity: 0.9;
    position: relative;
    z-index: 1;
}

.main-content {
    padding: 2rem;
}

.upload-section {
    margin-bottom: 2rem;
}

.upload-area {
    border: 2px dashed var(--border);
    border-radius: 15px;
    padding: 3rem 2rem;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
    background: linear-gradient(135deg, #f8fafc 0%, #f1f5f9 100%);
    position: relative;
    overflow: hidden;
}

.upload-area:hover {
    border-color: var(--primary);
    background: linear-gradient(135deg, #f0f9ff 0%, #e0f2fe 100%);
    transform: translateY(-2px);
}

.upload-area.drag-over {
    border-color: var(--primary);
    background: linear-gradient(135deg, #dbeafe 0%, #bfdbfe 100%);
    transform: scale(1.02);
}

.upload-icon {
    font-size: 4rem;
    color: var(--primary);
    margin-bottom: 1rem;
    animation: float 3s ease-in-out infinite;
}

@keyframes float {

    0%,
    100% {
        transform: translateY(0px);
    }

    50% {
        transform: translateY(-10px);
    }
}

.upload-text {
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--dark);
    margin-bottom: 0.5rem;
}

.upload-subtext {
    color: #6b7280;
    font-size: 0.9rem;
}

.file-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 1rem;
    margin-top: 2rem;
}

.file-item {
    background: white;
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 1rem;
    text-align: center;
    position: relative;
    transition: all 0.3s ease;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
}

.file-item:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.1);
}

.file-preview {
    width: 100%;
    height: 120px;
    object-fit: cover;
    border-radius: 8px;
    margin-bottom: 0.5rem;
}

.file-name {
    font-size: 0.8rem;
    color: var(--dark);
    font-weight: 500;
    margin-bottom: 0.25rem;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.file-size {
    font-size: 0.7rem;
    color: #6b7280;
}

.remove-file {
    position: absolute;
    top: 0.5rem;
    right: 0.5rem;
    background: var(--error);
    color: white;
    border: none;
    border-radius: 50%;
    width: 24px;
    height: 24px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
}

.remove-file:hover {
    background: #dc2626;
    transform: scale(1.1);
}

.options-section {
    background: #FFFDEE;
    border-radius: 15px;
    padding: 2rem;
    margin-bottom: 2rem;
    border: 1px solid var(--border);
}

.options-title {
    font-size: 1.3rem;
    font-weight: 600;
    color: var(--dark);
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.options-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
}

.option-group {
    background: white;
    border-radius: 10px;
    padding: 1.5rem;
    border: 1px solid var(--border);
}

.option-label {
    font-weight: 600;
    color: var(--dark);
    margin-bottom: 0.75rem;
    display: block;
}

.radio-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.radio-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    cursor: pointer;
    padding: 0.5rem;
    border-radius: 8px;
    transition: all 0.3s ease;
}

.radio-item:hover {
    background: #f3f4f6;
}

.radio-item input[type="radio"] {
    accent-color: #de9406;
}

.checkbox-item {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    cursor: pointer;
    padding: 1rem;
    background: white;
    border: 1px solid var(--border);
    border-radius: 10px;
    transition: all 0.3s ease;
}

.checkbox-item:hover {
    background: #f8fafc;
    border-color: var(--primary);
}

.checkbox-item input[type="checkbox"] {
    accent-color: #de9406;
    width: 18px;
    height: 18px;
}

.checkbox-label {
    font-weight: 500;
    color: var(--dark);
}

.action-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

.btn {
    padding: 0.75rem 2rem;
    border: none;
    border-radius: 10px;
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    text-decoration: none;
    text-align: center;
    min-width: 150px;
    justify-content: center;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: white;
    box-shadow: var(--shadow);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 15px 30px rgba(102, 126, 234, 0.4);
}

.btn-secondary {
    background: white;
    color: var(--dark);
    border: 2px solid var(--border);
}

.btn-secondary:hover {
    background: var(--light);
    border-color: var(--primary);
    color: var(--primary);
}

.btn:disabled {
    background: #9ca3af;
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

.loading {
    display: none;
    text-align: center;
    padding: 2rem;
}

.loading.show {
    display: block;
}

.spinner {
    width: 40px;
    height: 40px;
    border: 4px solid #f3f4f6;
    border-top: 4px solid var(--primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 0 auto 1rem;
}

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

    100% {
        transform: rotate(360deg);
    }
}

.message {
    padding: 1rem;
    border-radius: 10px;
    margin-bottom: 1rem;
    display: none;
}

.message.show {
    display: block;
}

.message.success {
    background: #ecfdf5;
    color: #065f46;
    border: 1px solid #bbf7d0;
}

.message.error {
    background: #fef2f2;
    color: #991b1b;
    border: 1px solid #fecaca;
}

@media (max-width: 768px) {
    .header h1 {
        font-size: 2rem;
    }

    .header p {
        font-size: 1rem;
    }

    .main-content {
        padding: 1rem;
    }

    .upload-area {
        padding: 2rem 1rem;
    }

    .options-grid {
        grid-template-columns: 1fr;
    }

    .action-buttons {
        flex-direction: column;
        align-items: center;
    }

    .btn {
        width: 100%;
        max-width: 300px;
    }
}