body{font-family:Arial;background:#f4f4f4;margin:0}
header{background:#5666a5;color:white;padding:15px}
nav button{margin-right:8px;padding:8px 12px}
main{max-width:900px;margin:auto;padding:20px}
.card{background:white;padding:20px;margin-bottom:20px;border-radius:10px}
input,select{width:100%;padding:10px;margin-top:10px}
table{width:100%;margin-top:15px;border-collapse:collapse}
td,th{border:1px solid #ddd;padding:8px;text-align:left}
.editable{background:#fff7cc}