:root{--w:980px;}
body{margin:0;font-family:Arial,Helvetica,sans-serif;background:#fff;color:#111}
.wrap{max-width:var(--w);margin:0 auto;padding:14px}
.top{display:flex;justify-content:space-between;align-items:center;padding:10px 0;border-bottom:1px solid #ddd}
a{color:#0b57d0;text-decoration:none}
a:hover{text-decoration:underline}
h1{margin:18px 0 10px}
input,textarea,button{font:inherit}
input,textarea{width:100%;padding:10px;border:1px solid #bbb;border-radius:6px}
button{padding:10px 14px;border:1px solid #999;border-radius:6px;background:#eee}
.nav a{margin-right:10px}
.err{color:#b00;font-weight:bold}
.ok{color:#060;font-weight:bold}
@media (max-width:640px){
  .wrap{padding:10px}
  .top{flex-direction:column;gap:6px;align-items:flex-start}
}