body{transition:background-color 0.3s ease}.theme-toggle{position:fixed;top:10px;right:10px;padding:10px 20px;border:none;border-radius:5px;cursor:pointer;background-size:contain;background-repeat:no-repeat;background-position:center;width:40px;height:40px}body.dark{background-color:#333;color:#fff}body.dark .theme-toggle{background-image:url("img/light-mode.svg")}body:not(.dark) .theme-toggle{background-image:url("img/dark-mode.svg")}.theme-toggle:hover{opacity:0.8}