.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}input[type=number]{width:250px;padding:.5rem;font-size:1rem;margin-right:1rem;border:1px solid #ccc;border-radius:4px;background-color:#f0f0f0;color:#000;box-sizing:border-box}.app.dark input[type=number]{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;border:none;background-color:#007bff;color:#fff;transition:background-color .2s ease}button:hover{background-color:#0056b3}.app.dark button{background-color:#1a73e8}h2{margin-top:1rem;color:#222}.app.dark h2{color:#ddd}h3{margin-top:2rem}p{line-height:1.5}footer{text-align:left;margin-top:2rem;font-size:1rem}footer p{margin:.5rem 0;color:#555}.app.dark footer p{color:#aaa}footer a{text-decoration:none;font-weight:700;color:#007bff}footer a:hover{color:#0056b3}footer a.link{text-decoration:underline}.result-box{background-color:#f9f9f9;border:1px solid #ddd;border-radius:8px;padding:1rem;margin-top:1rem;box-shadow:0 2px 5px #0000000d}.app.dark .result-box{background-color:#1e1e1e;border:1px solid #444}