*{
box-sizing:border-box;
}

body{

margin:0;

font-family:

Arial,"Microsoft YaHei";

background:#f5f6fa;

color:#333;

}


.header{

height:60px;

background:#111827;

color:white;

display:flex;

align-items:center;

padding:0 30px;

font-size:22px;

}


.menu{

width:220px;

background:#1f2937;

position:fixed;

top:60px;

bottom:0;

left:0;

}


.menu a{

display:block;

padding:15px 25px;

color:white;

text-decoration:none;

}


.menu a:hover{

background:#374151;

}


.main{

margin-left:220px;

padding:30px;

}


.card{

background:white;

padding:20px;

border-radius:8px;

margin-bottom:20px;

}


button{

background:#2563eb;

color:white;

border:0;

padding:8px 15px;

border-radius:5px;

cursor:pointer;

}


button.delete{

background:#dc2626;

}


input,select,textarea{

width:100%;

padding:10px;

margin:6px 0 15px;

border:1px solid #ddd;

border-radius:5px;

}


table{

width:100%;

border-collapse:collapse;

background:white;

}


th,td{

padding:12px;

border-bottom:1px solid #eee;

text-align:center;

}


img{

max-width:100px;

}