body{font-family:system-ui,Arial;margin:0;padding:20px;background:#f6f7fb}
.container{max-width:900px;margin:0 auto;background:#fff;padding:20px;border-radius:8px;box-shadow:0 6px 18px rgba(0,0,0,0.08)}
h1{margin-top:0}
.list{width:100%;border-collapse:collapse}
.list th,.list td{border:1px solid #e6e6e6;padding:8px;text-align:left}
label{display:block;margin:8px 0}
input,textarea,select{width:100%;padding:8px;border:1px solid #ddd;border-radius:4px}
.btn{display:inline-block;padding:6px 10px;background:#0366d6;color:#fff;border-radius:6px;text-decoration:none}
.error{color:#b00020}
.nav{float:right}
header:after{content:'';display:block;clear:both}