:root {

    --bg-color: #f3f4f6;

    --surface-color: #ffffff;

    --text-primary: #111827;

    --text-secondary: #4b5563;

    --border-color: #e5e7eb;

    --primary-color: #138708;

    --primary-hover: #107207;

    --secondary-color: #FF9935;

    --secondary-hover: #E68A30;

    --error-color: #ef4444;

    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);

    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);

    --radius-md: 8px;

    --radius-lg: 12px;

}



* {

    box-sizing: border-box;

    margin: 0;

    padding: 0;

}



body {

    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;

    background-color: var(--bg-color);

    color: var(--text-primary);

    line-height: 1.5;

}



/* Layout */

.app-container {

    display: flex;

    flex-wrap: wrap;

    height: 100vh;

    overflow-y: auto;

}



.form-pane {

    flex: 1 1 35vw;

    min-width: 320px;

    background-color: var(--surface-color);

    border-right: 1px solid var(--border-color);

    display: flex;

    flex-direction: column;

    padding: 2rem;

    box-shadow: var(--shadow-md);

    z-index: 10;

}



.preview-pane {

    flex: 1 1 55vw;

    background-color: #e2e8f0;

    overflow: auto;

    padding: 2rem;

    display: flex;

    justify-content: center;

    align-items: flex-start;

}



/* Header */

header {

    display: flex;

    justify-content: space-between;

    align-items: center;

    margin-bottom: 2rem;

    padding-bottom: 1rem;

    border-bottom: 1px solid var(--border-color);

}



header h1 {

    font-size: 1.5rem;

    font-weight: 700;

    color: var(--text-primary);

}



.actions {

    display: flex;

    gap: 0.5rem;

}



/* Buttons */

button {

    cursor: pointer;

    border: none;

    padding: 0.5rem 1rem;

    border-radius: var(--radius-md);

    font-weight: 500;

    font-size: 0.875rem;

    transition: all 0.2s;

}



.btn-primary {

    background-color: var(--primary-color);

    color: white;

}

.btn-primary:hover { background-color: var(--primary-hover); }



.btn-secondary {

    background-color: var(--secondary-color);

    color: white;

}

.btn-secondary:hover { background-color: var(--secondary-hover); }



/* Forms */

.form-section {

    margin-bottom: 2rem;

    background: #fafafa;

    padding: 1.5rem;

    border-radius: var(--radius-lg);

    border: 1px solid var(--border-color);

}



.form-section h2 {

    font-size: 1.125rem;

    margin-bottom: 1rem;

    color: var(--text-secondary);

    border-bottom: 2px solid var(--border-color);

    padding-bottom: 0.5rem;

}



.input-grid {

    display: grid;

    grid-template-columns: 1fr 1fr;

    gap: 1rem;

}



.form-group { display: flex; flex-direction: column; }

.form-group.full-width { grid-column: span 2; }



label {

    font-size: 0.875rem;

    font-weight: 600;

    margin-bottom: 0.25rem;

    color: var(--text-secondary);

}



input, select, textarea {

    padding: 0.5rem 0.75rem;

    border: 1px solid var(--border-color);

    border-radius: var(--radius-md);

    font-family: inherit;

    font-size: 0.875rem;

    transition: border-color 0.2s, box-shadow 0.2s;

}



input:focus, select:focus, textarea:focus {

    outline: none;

    border-color: var(--primary-color);

    box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);

}



/* Table */

.table-responsive {

    overflow-x: auto;

}

.items-entry-table {

    width: 100%;

    min-width: 280px;

    border-collapse: collapse;

}

.items-entry-table th {

    text-align: left;

    font-size: 0.75rem;

    text-transform: uppercase;

    color: var(--text-secondary);

    padding: 0.5rem;

    border-bottom: 1px solid var(--border-color);

}

.items-entry-table td {

    padding: 0.5rem;

}

.items-entry-table input, .items-entry-table select {

    width: 100%;

}

.btn-remove {

    background: var(--error-color);

    color: white;

    padding: 0.25rem 0.5rem;

    border-radius: var(--radius-md);

    font-size: 0.75rem;

}



/* Hide spin buttons for GST input since it uses a datalist */

.item-gst::-webkit-outer-spin-button,

.item-gst::-webkit-inner-spin-button {

    -webkit-appearance: none;

    margin: 0;

}

.item-gst {

    -moz-appearance: textfield;

    appearance: textfield;

}



.mt-2 { margin-top: 1rem; }

.whitespace-pre { white-space: pre-wrap; }



/* Totals */

.totals-summary p { margin: 0.25rem 0; color: var(--text-secondary); }

.totals-summary h3 { margin-top: 0.5rem; color: var(--text-primary); font-size: 1.25rem; }



/* Utility */

.error-msg {

    color: var(--error-color);

    font-size: 0.75rem;

    margin-top: 0.25rem;

}

input:invalid:not(:focus):not(:placeholder-shown) {

    border-color: var(--error-color);

}



/* Modal */

.modal-overlay {

    position: fixed;

    top: 0; left: 0; width: 100vw; height: 100vh;

    background: rgba(0,0,0,0.5);

    display: flex;

    align-items: center; justify-content: center;

    z-index: 100;

}

.modal-content {

    background: var(--surface-color);

    padding: 2rem;

    border-radius: var(--radius-lg);

    width: 90%;

    max-width: 600px;

    max-height: 90vh;

    overflow-y: auto;

    box-shadow: var(--shadow-md);

}

.modal-content h2 { margin-bottom: 1.5rem; color: var(--text-primary); }



/* Responsive Design */

@media (max-width: 992px) {

    .form-pane {

        flex: 1 1 100vw;

        border-right: none;

        border-bottom: 1px solid var(--border-color);

    }

    .preview-pane {

        flex: 1 1 100vw;

        min-height: 100vh;

        overflow-x: auto;

        justify-content: flex-start;

    }

}



@media (max-width: 1200px) {

    .input-grid {

        grid-template-columns: 1fr;

    }

    .form-group.full-width {

        grid-column: span 1;

    }

}





/* Global Navigation */

.global-nav {

    display: flex;

    justify-content: space-between;

    align-items: center;

    background-color: var(--primary-color);

    color: white;

    padding: 15px 30px;

    box-shadow: 0 4px 10px rgba(0,0,0,0.15);

    position: sticky;

    top: 0;

    z-index: 1000;

}



.global-nav .nav-brand {

    font-size: 22px;

    font-weight: bold;

    letter-spacing: 0.5px;

}



.global-nav .nav-links a.nav-btn {

    color: var(--primary-color);

    background-color: white;

    text-decoration: none;

    margin-left: 20px;

    font-size: 15px;

    font-weight: 600;

    transition: all 0.2s ease-in-out;

    padding: 8px 16px;

    border-radius: 20px;

    box-shadow: 0 2px 5px rgba(0,0,0,0.1);

}



.global-nav .nav-links a.nav-btn:hover {

    background-color: #f0f0f0;

    transform: translateY(-1px);

    box-shadow: 0 4px 8px rgba(0,0,0,0.15);

}



/* Enhanced Buttons */

button {

    cursor: pointer;

    border: none;

    padding: 0.6rem 1.2rem;

    border-radius: 6px;

    font-weight: 600;

    font-size: 0.9rem;

    transition: all 0.2s ease;

    box-shadow: 0 2px 4px rgba(0,0,0,0.08);

    display: inline-flex;

    align-items: center;

    justify-content: center;

    gap: 0.4rem;

    white-space: nowrap;

}



.btn-primary {

    background-color: var(--primary-color);

    color: white;

}

.btn-primary:hover {

    background-color: var(--primary-hover);

    transform: translateY(-1px);

    box-shadow: 0 4px 8px rgba(0,0,0,0.15);

}

.btn-primary:active {

    transform: translateY(0);

}



.btn-secondary {

    background-color: var(--secondary-color);

    color: white;

}

.btn-secondary:hover {

    background-color: var(--secondary-hover);

    transform: translateY(-1px);

    box-shadow: 0 4px 8px rgba(0,0,0,0.15);

}

.btn-secondary:active {

    transform: translateY(0);

}



/* Mandatory Field Indicators */
.form-group:has(input[required]) label::after,
.form-group:has(select[required]) label::after,
.form-group:has(textarea[required]) label::after {
    content: " *";
    color: #e74c3c;
}