body { font-family:sans-serif; background:#f5f5f5; margin:0; padding:0; }
.card { background:white; padding:20px; margin:20px auto; border-radius:8px; max-width:400px; box-shadow:0 2px 8px rgba(0,0,0,0.2);}
h1,h2,h3{margin:10px 0;}
input,select,button { margin:5px 0; padding:8px; width:100%; }
.link-card{background:#eef;margin:10px 0;padding:10px;border-radius:6px;}
.error{color:red;} .success{color:green;}