/* Body */
body {
    font-family: Arial, sans-serif;
    background-color: #f4f4f9;
    margin: 0;
    padding: 20px; /* add space around the container */
}

/* Container */
.container {
    max-width: 900px;
    margin: 0 auto; /* center horizontally */
    padding: 25px 30px; /* internal spacing inside container */
    background-color: #fff;
    border-radius: 8px;
    box-shadow: 0px 4px 15px rgba(0,0,0,0.1);
}

/* Ensure container is not too wide on small screens */
@media (max-width: 950px) {
    .container {
        padding: 20px;
        margin: 20px; /* space around container */
    }
}

/* Headings */
h1, h2, h3, h4 {
    color: #333;
    margin-bottom: 20px;
}

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

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

th {
    background-color: #f2f2f2;
}

/* Inputs and selects */
input[type="text"],
input[type="number"],
select {
    width: 100%;
    padding: 8px;
    margin: 2px 0;
    box-sizing: border-box;
    border-radius: 4px;
    border: 1px solid #ccc;
}

/* Buttons */
button, input[type="submit"] {
    padding: 8px 14px;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    color: #fff;
    font-weight: bold;
}

button:hover, input[type="submit"]:hover {
    opacity: 0.9;
}

/* Action buttons colors */
#addRow {
    background-color: #2196F3;
}

#addRow:hover {
    background-color: #1976d2;
}

.removeRow {
    background-color: #f44336;
}

.removeRow:hover {
    background-color: #d32f2f;
}

/* Links */
a {
    text-decoration: none;
    color: #2196F3;
    margin-right: 5px;
}

a:hover {
    text-decoration: underline;
}

/* Highlight totals */
#subtotal, #balance_payable {
    background-color: #e7f3ff;
    font-weight: bold;
}