/* Page Background */
body {
    background: linear-gradient(135deg, #0f2027, #203a43, #2c5364);
    font-family: 'Segoe UI', sans-serif;
}

/* Billing Card */
.container {
    background: #ffffff;
    margin-top: 40px;
    padding: 30px;
    border-radius: 15px;
    box-shadow: 0 15px 35px rgba(0,0,0,0.3);
}

/* Title */
h2 {
    font-weight: bold;
    letter-spacing: 1px;
}

/* Form controls */
.form-control {
    margin-bottom: 15px;
    border-radius: 8px;
}

/* Add Button */
#btn_id {
    width: 100%;
    font-size: 18px;
    font-weight: bold;
    border-radius: 8px;
    padding: 10px;
    transition: 0.3s;
}

#btn_id:hover {
    background-color: #0056b3;
}

/* Table Container */
.bill-table {
    margin-top: 25px;
    overflow-x: auto;
}

/* Table Styling */
table {
    border-radius: 10px;
    overflow: hidden;
}

/* Table Header */
table thead {
    background: #2c5364;
    color: white;
    font-size: 16px;
}

/* Table Body */
table tbody tr:nth-child(odd) {
    background-color: #f8f9fa;
}

table tbody tr:nth-child(even) {
    background-color: #ffffff;
}

table tbody tr:hover {
    background-color: #e3f2fd;
    transition: 0.3s;
}

/* Grand Total Row */
.grand-total-row {
    background-color: #198754;
    color: white;
    font-size: 18px;
}

/* Strong text */
.grand-total-row strong {
    letter-spacing: 1px;
}
/* Sales Calculator Title */
.sales-title {
    font-size: 32px;
    font-weight: bold;
    text-transform: uppercase;
    letter-spacing: 2px;
    color: #2c5364;
    margin-bottom: 20px;
    position: relative;
}

/* Decorative underline effect */
.sales-title::after {
    content: "";
    width: 120px;
    height: 4px;
    background: linear-gradient(90deg, #198754, #0d6efd);
    display: block;
    margin: 10px auto 0;
    border-radius: 5px;
}