body {
font-family: Arial;
max-width:900px;
margin:30px auto;
padding:20px;
}


h1 {
text-align:center;
}


.box {
border:1px solid #ccc;
padding:20px;
border-radius:10px;
margin-bottom:20px;
}


button {
padding:10px 20px;
cursor:pointer;
}


input {
padding:10px;
}


table {
width:100%;
border-collapse:collapse;
}


th,td {
border:1px solid #ccc;
padding:10px;
text-align:center;
}


th {
background:#eee;
}


.ok {
color:green;
font-weight:bold;
}