:root{--primary-color: #007BFF;--primary-color-dark: #0056b3;--secondary-color: #FFD700;--background-light: #f9f9f9;--background-dark: #121212;--text-light: #333;--text-dark: #e0e0e0;--nav-bg-light: #007BFF;--nav-bg-dark: #1f1f1f;--button-disabled-light: #a3c0f3;--button-disabled-dark: #555;--border-light: #ddd;--border-dark: #333}body{margin:0;font-family:Helvetica Neue,Helvetica,Arial,sans-serif;background:var(--background-light);color:var(--text-light);line-height:1.6;transition:background .3s ease,color .3s ease}nav{background:var(--nav-bg-light);color:var(--text-dark);display:flex;justify-content:center;padding:1rem;box-shadow:0 2px 4px #0000001a}nav a{color:var(--text-light);margin:0 1rem;text-decoration:none;font-size:1.1rem;transition:color .3s ease}nav a:hover{color:var(--secondary-color)}.container{max-width:800px;margin:2rem auto;padding:0 1rem}h1{font-size:2.5rem;text-align:center;margin-bottom:1rem}button{background:var(--primary-color);color:#fff;border:none;padding:.8rem 1.2rem;font-size:1rem;border-radius:4px;cursor:pointer;transition:background .3s ease;margin:.5rem .5rem .5rem 0}button:disabled{background:var(--button-disabled-light);cursor:not-allowed}button:hover:not(:disabled){background:var(--primary-color-dark)}textarea{width:100%;padding:1rem;border:1px solid var(--border-light);border-radius:4px;font-size:1rem;margin-top:1rem;resize:vertical;background:var(--background-light);color:var(--text-light);transition:background .3s ease,color .3s ease,border-color .3s ease}#output{margin-top:20px;font-size:1.1rem;min-height:20px;text-align:center}@media (prefers-color-scheme: dark){body{background:var(--background-dark);color:var(--text-dark)}nav{background:var(--nav-bg-dark)}textarea{background:var(--background-dark);color:var(--text-dark);border-color:var(--border-dark)}button:disabled{background:var(--button-disabled-dark)}}@media (max-width: 600px){nav{flex-direction:column;padding:.5rem}nav a{margin:.5rem 0;font-size:1rem}h1{font-size:2rem}button{padding:.7rem 1rem;font-size:.9rem;margin:.3rem}.container{padding:0 .5rem;margin:1rem auto}}