.header{position:fixed;top:0;width:100%;background:var(--bg-color);color:var(--text-color);padding:1rem 2rem;display:flex;justify-content:space-between;align-items:center;border-bottom:1px solid gray;z-index:1000}.header .logo{font-weight:700;font-size:1.5rem}.header nav a{margin:0 .5rem;text-decoration:none;color:var(--text-color)}.header nav a:hover{text-decoration:underline}.header select{padding:.3rem .6rem;border-radius:5px}body{margin:0;transition:all .3s ease}.theme1{--bg-color: #ffffff;--text-color: #000000;--card-bg: #f9f9f9;--card-text: #000000;--font-family: Arial, sans-serif}.theme2{--bg-color: #121212;--text-color: #ffffff;--card-bg: #1f1f1f;--card-text: #ffffff;--font-family: Georgia, serif}.theme3{--bg-color: #ffe4f0;--text-color: #3a3a3a;--card-bg: #ffffff;--card-text: #3a3a3a;--font-family: "Pacifico", cursive}body{background-color:var(--bg-color);color:var(--text-color);font-family:var(--font-family)}.home-container{padding:6rem 2rem}.main-button{padding:10px 16px;margin-bottom:20px;cursor:pointer}.product-grid{display:grid;gap:1.5rem;grid-template-columns:repeat(auto-fit,minmax(250px,1fr))}.product-card{border:1px solid #ccc;padding:1rem;border-radius:8px;background-color:var(--card-bg);color:var(--card-text)}.product-image{width:100%;height:200px;object-fit:contain;margin-bottom:.5rem}.product-title{font-size:1rem;margin-bottom:.5rem}.product-price{font-weight:700;margin-bottom:.5rem}.product-description{font-size:.9rem;margin-bottom:.5rem}.product-category,.product-rating{font-size:.85rem;margin-bottom:.5rem}