.app{background-color:#fff;color:#000;font-family:sans-serif;min-height:100vh;padding:1rem;transition:background-color .3s ease,color .3s ease}.app.dark{background-color:#121212;color:#fff}h1{margin-bottom:1rem}textarea{width:99%;height:300px;margin-bottom:1rem;padding:.5rem;font-family:monospace;font-size:1rem;border:1px solid #ccc;border-radius:4px;resize:vertical;box-sizing:border-box;background-color:#f0f0f0;color:#000}.app.dark textarea{background-color:#1e1e1e;color:#eee;border:1px solid #444}button{padding:.5rem 1rem;font-size:1rem;margin-right:1rem;margin-bottom:.5rem;cursor:pointer;border-radius:7px}footer{text-align:left;margin-top:2rem;font-size:1rem}footer p{margin:.5rem 0;color:#555}footer a{text-decoration:none;font-weight:700;color:#007bff}footer a:hover{color:#0056b3}footer a.link{text-decoration:underline}