body{
    font-family: Arial, sans-serif;
    background:#f4f4f4;
    margin:0;
    padding:20px;
}

.container{
    max-width:900px;
    margin:auto;
    background:rgb(245, 241, 241);
    padding:20px;
    border-radius:10px;
    box-shadow:0 0 10px rgba(0,0,0,0.1);
}

h1{
    text-align:center;
    color:#333;
}

input, select{
    width:100%;
    padding:10px;
    margin-top:5px;
    margin-bottom:15px;
    border:1px solid #ccc;
    border-radius:5px;
}

button{
    padding:12px 20px;
    border:none;
    border-radius:5px;
    cursor:pointer;
    margin:5px;
}

.add-btn{
    background:#2196F3;
    color:white;
}

.pdf-btn{
    background:#4CAF50;
    color:white;
}

.whatsapp-btn{
    background:#25D366;
    color:white;
}

table{
    width:100%;
    border-collapse:collapse;
    margin-top:15px;
}

table, th, td{
    border:1px solid #ddd;
}

th, td{
    padding:10px;
    text-align:center;
}

.summary{
    margin-top:20px;
    font-size:18px;
}

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