.is-invoice-container {
    max-width: 1200px;
    margin: 20px auto;
}
.is-form {
    background: #fff;
    padding: 25px;
    border-radius: 12px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
    margin-bottom: 30px;
}
.is-preview {
    background: #f0f0f0;
    padding: 20px;
    border-radius: 12px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}
.is-preview .invoice-preview-inner {
    transition: all 0.3s ease;
}

/* Two-column layout */
.is-two-columns {
    display: flex;
    gap: 40px;
    margin-bottom: 30px;
    flex-wrap: wrap;
}
.is-left-column {
    flex: 2;
}
.is-right-column {
    flex: 1;
    text-align: right;
}
.is-right-column h1 {
    margin-top: 0;
}
.is-right-column label {
    display: block;
    margin-bottom: 10px;
}
.is-right-column input {
    width: 100%;
}

/* Left column sections */
.is-business, .is-billto, .is-shipto {
    margin-bottom: 20px;
}
.is-business input, .is-business textarea,
.is-billto input, .is-billto textarea,
.is-shipto textarea {
    width: 100%;
    padding: 8px;
    margin-bottom: 12px;
    border: 1px solid #ddd;
    border-radius: 6px;
    box-sizing: border-box;
}

/* Items table */
.items-table {
    width: 100%;
    border-collapse: collapse;
    margin-bottom: 15px;
}
.items-table th, .items-table td {
    border: 1px solid #ddd;
    padding: 8px;
    text-align: left;
}
.items-table input {
    width: 100%;
    padding: 6px;
    box-sizing: border-box;
}
.add-item {
    background: #007cba;
    color: white;
    border: none;
    padding: 8px 16px;
    border-radius: 4px;
    cursor: pointer;
    margin: 10px 0;
}
.remove-item {
    background: #dc3545;
    color: white;
    border: none;
    padding: 4px 8px;
    border-radius: 4px;
    cursor: pointer;
}

/* Notes & Terms side by side */
.is-notes-terms {
    display: flex;
    gap: 30px;
    margin: 20px 0;
}
.is-notes-terms > div {
    flex: 1;
}
.is-notes-terms textarea {
    width: 100%;
    padding: 8px;
    border: 1px solid #ddd;
    border-radius: 6px;
    min-height: 80px;
}

/* Totals section */
.is-totals {
    text-align: right;
    max-width: 350px;
    margin-left: auto;
    margin-top: 20px;
}
.is-totals p {
    margin: 8px 0;
}
.small-input {
    width: 120px !important;
    display: inline-block;
}
.toggle-link {
    background: none;
    border: none;
    color: #007cba;
    cursor: pointer;
    font-size: 14px;
    padding: 0;
    margin: 5px 0;
}
#discount_shipping_fields {
    margin-top: 10px;
    padding-top: 10px;
    border-top: 1px dashed #ddd;
}

/* Actions */
.is-actions {
    margin-top: 20px;
    display: flex;
    gap: 10px;
}
.download-btn {
    background: #22C55E;
    border: none;
    padding: 10px 20px;
    border-radius: 6px;
    color: white;
    cursor: pointer;
    font-size: 16px;
}
.dark-toggle {
    background: #333;
    border: none;
    padding: 10px 20px;
    border-radius: 6px;
    color: white;
    cursor: pointer;
}
.no-items-message {
    text-align: center;
    color: #999;
    padding: 20px;
    border: 1px dashed #ccc;
    border-radius: 8px;
    background: #fafafa;
}

/* Responsive */
@media (max-width: 768px) {
    .is-two-columns {
        flex-direction: column;
        gap: 20px;
    }
    .is-right-column {
        text-align: left;
    }
    .is-notes-terms {
        flex-direction: column;
        gap: 15px;
    }
    .is-totals {
        max-width: 100%;
    }
}