* {box-sizing:border-box; font-family:Arial, sans-serif; margin:0; padding:0;}
body {background:#1a1a2e; color:#fff; padding:1rem;}
.wadah {max-width:450px; margin:2rem auto; background:#16213e; padding:1.5rem; border-radius:8px;}
input,button {width:100%; padding:0.7rem; margin:0.4rem 0; border-radius:6px; border:none; font-size:1rem;}
button {background:#00f5d4; color:#000; font-weight:bold;}