:root{--background:#fff;--foreground:#000;--accent:#222;--border:#000;--hover:#f0f0f0}[data-theme=dark]{--background:#000;--foreground:#f8f8f8;--accent:#ddd;--border:#f8f8f8;--hover:#111}body{color:var(--foreground);background:var(--background);font-family:Arial,Helvetica,sans-serif;margin:0;padding:0;transition:background .2s,color .2s;height:100vh;display:flex;flex-direction:column}*{box-sizing:border-box}button{cursor:pointer;background:transparent;border:1px solid var(--border);color:var(--foreground);padding:.5rem 1rem;font-size:1rem;transition:all .2s}button:hover{background:var(--foreground);color:var(--background)}input,select,textarea{background:transparent;border:1px solid var(--border);color:var(--foreground);padding:.5rem;font-size:1rem;font-family:inherit}input:focus,select:focus,textarea:focus{outline:2px solid var(--foreground);border-color:transparent}