:root {
            --primary: #4361ee;
            --secondary: #3f37c9;
            --light: #f8f9fa;
            --dark: #212529;
            --gray: #6c757d;
        }
        
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
        }
        
        body {
            background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
            color: var(--dark);
            line-height: 1.6;
            min-height: 100vh;
            padding: 20px;
        }
        
        header {
            text-align: center;
            padding: 3rem 0;
            margin-bottom: 2rem;
        }
        
        .logo {
            font-size: 2.5rem;
            font-weight: 700;
            background: linear-gradient(45deg, var(--primary), var(--secondary));
            -webkit-background-clip: text;
            background-clip: text;
            color: transparent;
            margin-bottom: 0.5rem;
        }
        
        .tagline {
            font-size: 1.2rem;
            color: var(--gray);
            max-width: 600px;
            margin: 0 auto;
        }
        
        .container {
            max-width: 1200px;
            margin: 0 auto;
        }
        
        .portfolio-grid {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
            gap: 2rem;
            margin-top: 2rem;
        }
        
        .portfolio-card {
            background: white;
            border-radius: 12px;
            overflow: hidden;
            box-shadow: 0 10px 20px rgba(0,0,0,0.1);
            transition: transform 0.3s ease, box-shadow 0.3s ease;
        }
        
        .portfolio-card:hover {
            transform: translateY(-10px);
            box-shadow: 0 15px 30px rgba(0,0,0,0.15);
        }
        
        .card-image {
            height: 200px;
            overflow: hidden;
        }
        
        .card-image img {
            width: 100%;
            height: 100%;
            object-fit: cover;
            transition: transform 0.5s ease;
        }
        
        .portfolio-card:hover .card-image img {
            transform: scale(1.05);
        }
        
        .card-content {
            padding: 1.5rem;
        }
        
        .card-title {
            font-size: 1.5rem;
            margin-bottom: 0.5rem;
            color: var(--primary);
        }
        
        .card-description {
            color: var(--gray);
            margin-bottom: 1.2rem;
            height: 80px;
            overflow: hidden;
        }
        
        .card-meta {
            display: flex;
            justify-content: space-between;
            font-size: 0.9rem;
            color: var(--gray);
            margin-bottom: 1.5rem;
        }
        
        .download-btn {
            display: block;
            width: 100%;
            padding: 12px;
            background: linear-gradient(45deg, var(--primary), var(--secondary));
            color: white;
            text-align: center;
            border-radius: 6px;
            font-weight: 600;
            text-decoration: none;
            border: none;
            cursor: pointer;
            transition: background 0.3s ease;
        }
        
        .download-btn:hover {
            background: linear-gradient(45deg, var(--secondary), #2a2a72);
        }
        
        .download-btn-MED {
            display: block;
            width: 100%;
            padding: 12px;
            background: linear-gradient(45deg, #5F9EA0, #708090);
            color: white;
            text-align: center;
            border-radius: 6px;
            font-weight: 600;
            text-decoration: none;
            border: none;
            cursor: pointer;
            transition: background 0.3s ease;
        }
        
        .download-btn-MED:hover {
            background: linear-gradient(45deg, #5A8C8E , #5A6A7D);
        }

        .download-btn-HIG {
            display: block;
            width: 100%;
            padding: 12px;
            background: linear-gradient(45deg, #808080, #a9a9a9);
            color: white;
            text-align: center;
            border-radius: 6px;
            font-weight: 600;
            text-decoration: none;
            border: none;
            cursor: pointer;
            transition: background 0.3s ease;
        }
        
        .download-btn-HIG:hover {
            background: linear-gradient(45deg, #a9a9a9 , #707070);
        }

        .download-btn-COD {
            display: block;
            width: 100%;
            padding: 12px;
            background: linear-gradient(45deg, #FFD700, #FFA500);
            color: white;
            text-align: center;
            border-radius: 6px;
            font-weight: 600;
            text-decoration: none;
            border: none;
            cursor: pointer;
            transition: background 0.3s ease;
        }
        
        .download-btn-COD:hover {
            background: linear-gradient(45deg, #FFA500 , #FF8C00);
        }

        footer {
            text-align: center;
            padding: 3rem 0 2rem;
            color: var(--gray);
            margin-top: 4rem;
        }
        
        .filter-bar {
            display: flex;
            gap: 1rem;
            justify-content: center;
            margin-bottom: 2rem;
            flex-wrap: wrap;
        }
        
        .filter-btn {
            padding: 8px 16px;
            border: 2px solid var(--primary);
            border-radius: 30px;
            background: transparent;
            color: var(--primary);
            cursor: pointer;
            font-weight: 500;
            transition: all 0.3s ease;
        }
        
        .filter-btn:hover, .filter-btn.active {
            background: var(--primary);
            color: white;
        }
        
        @media (max-width: 768px) {
            .portfolio-grid {
                grid-template-columns: 1fr;
            }
            
            .filter-bar {
                justify-content: flex-start;
            }
        }