:root {
    --header-height: 60px;
    --sidebar-width: 250px;
    --footer-height: 40px;
    --primary-color: #5e7a95;
    --content-bg: #ffffff;
    --sheet-bg: #ffffff;
    --sheet-border: #d7dee8;
    --sheet-border-strong: #c6d0dc;
    --sheet-muted-bg: #eef3f8;
    --sheet-grid-bg: #f4f7fb;
    --sheet-text: #1f2937;
    --sheet-subtext: #64748b;
    --sheet-accent: #5e7a95;
    --sheet-accent-soft: #e6eef5;
    --sheet-danger-soft: #f4e7e7;
    --sheet-warn-soft: #f6f4ef;
}

body {
    overflow: hidden;
    font-family: 'Noto Sans KR', sans-serif;
    background-color: var(--sheet-grid-bg);
    color: var(--sheet-text);
}

/* Header */
#header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: var(--header-height);
    z-index: 1030;
    background-color: #f8fafc;
    box-shadow: 0 1px 0 rgba(148, 163, 184, 0.22);
    display: flex;
    align-items: center;
    padding: 0 1.5rem;
}

/* Sidebar */
#sidebar-wrapper {
    position: fixed;
    top: var(--header-height);
    left: 0;
    width: var(--sidebar-width);
    height: calc(100vh - var(--header-height) - var(--footer-height));
    overflow-y: auto;
    background-color: #fbfcfe;
    border-right: 1px solid var(--sheet-border);
    transition: width 0.25s ease, margin-left 0.25s ease;
    z-index: 1020;
}

#sidebar-wrapper .list-group-item {
    border: none;
    padding: 0.75rem 1.25rem;
    font-size: 0.95rem;
    background: transparent;
    color: #334155;
}

#sidebar-wrapper .list-group-item.active {
    background-color: #edf2f6;
    color: var(--sheet-accent);
    font-weight: bold;
    border-right: 4px solid var(--sheet-accent);
}

/* Main Content */
#page-content-wrapper {
    position: absolute;
    top: var(--header-height);
    left: var(--sidebar-width);
    width: calc(100% - var(--sidebar-width));
    height: calc(100vh - var(--header-height) - var(--footer-height));
    overflow-y: auto;
    background:
        linear-gradient(to bottom, #f9fbfd 0, #f9fbfd 60px, var(--sheet-grid-bg) 60px, var(--sheet-grid-bg) 100%);
    padding: 0;
    transition: left 0.25s ease, width 0.25s ease;
}

/* Footer */
#footer {
    position: fixed;
    bottom: 0;
    left: 0;
    width: 100%;
    height: var(--footer-height);
    background-color: #f8fafc;
    border-top: 1px solid var(--sheet-border);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1030;
    font-size: 0.85rem;
    color: #6c757d;
}

/* Toggled State (Collapsed Sidebar) */
body.sb-sidenav-toggled #sidebar-wrapper {
    margin-left: calc(-1 * var(--sidebar-width));
}

body.sb-sidenav-toggled #page-content-wrapper {
    left: 0;
    width: 100%;
}

/* Responsive */
@media (max-width: 768px) {
    :root {
        --footer-height: 0px;
    }

    #header {
        padding: 0 0.75rem;
    }

    #header #menu-toggle {
        margin-right: 0.6rem !important;
        padding: 0.35rem 0.55rem;
    }

    #header .fs-5 {
        font-size: 1rem !important;
        white-space: nowrap;
    }

    #header .dropdown-toggle {
        max-width: 120px;
        overflow: hidden;
        text-overflow: ellipsis;
        white-space: nowrap;
    }

    #sidebar-wrapper {
        margin-left: calc(-1 * var(--sidebar-width));
    }

    #page-content-wrapper {
        left: 0;
        width: 100%;
        overflow-x: hidden;
    }

    #footer {
        display: none;
    }

    /* Toggle show */
    body.sb-sidenav-toggled #sidebar-wrapper {
        margin-left: 0;
    }
}

/* Global sheet layout */
#page-content-wrapper > .d-flex.bg-white.border-bottom {
    background: #f8fafc !important;
    border-bottom: 1px solid var(--sheet-border) !important;
    box-shadow: inset 0 -1px 0 rgba(198, 208, 220, 0.9);
}

.container-fluid.p-4,
.container-fluid.px-4.py-3 {
    background: var(--sheet-grid-bg);
}

/* Utility */
.card,
.sheet-card,
.sheet-panel {
    border: 1px solid var(--sheet-border);
    border-radius: 10px;
    background: var(--sheet-bg);
    box-shadow: 0 6px 18px rgba(15, 23, 42, 0.05);
}

.sheet-panel-header {
    padding: 10px 14px;
    border-bottom: 1px solid var(--sheet-border);
    background: var(--sheet-muted-bg);
    font-size: 14px;
    font-weight: 700;
    color: var(--sheet-text);
}

.form-label {
    font-weight: 500;
    color: #475569;
}

.card-header,
.sheet-card-header,
.sheet-panel > .border-bottom,
.card-footer {
    background: var(--sheet-muted-bg) !important;
    border-bottom: 1px solid var(--sheet-border) !important;
    color: var(--sheet-text) !important;
}

.card-footer {
    border-top: 1px solid var(--sheet-border) !important;
}

.card-body,
.sheet-card-body {
    background: var(--sheet-bg);
}

.table-responsive {
    border-radius: 0 0 10px 10px;
}

.table {
    --bs-table-bg: transparent;
    --bs-table-striped-bg: #f8fafc;
    --bs-table-hover-bg: #edf2f6;
    --bs-table-border-color: var(--sheet-border);
    margin-bottom: 0;
}

.table > :not(caption) > * > * {
    padding: 0.72rem 0.7rem;
    border-color: var(--sheet-border);
    color: var(--sheet-text);
    vertical-align: middle;
    text-align: center;
}

.table thead th,
.table-light th,
.table-light td {
    background: #f8fafc !important;
    color: var(--sheet-text);
    font-weight: 700;
    white-space: nowrap;
}

.table tbody tr:hover > * {
    background: #edf2f6;
}

.sheet-panel .table:not(.ledger-sheet),
.sheet-card .table:not(.ledger-sheet) {
    table-layout: fixed;
    margin-bottom: 0;
}

.sheet-panel .table:not(.ledger-sheet) thead th,
.sheet-card .table:not(.ledger-sheet) thead th {
    background: var(--sheet-muted-bg) !important;
    border: 1px solid #d3dce8;
    font-size: 12px;
    font-weight: 700;
    white-space: nowrap;
    padding: 7px 8px;
    vertical-align: middle;
    text-align: center;
}

.sheet-panel .table:not(.ledger-sheet) tbody td,
.sheet-panel .table:not(.ledger-sheet) tfoot td,
.sheet-card .table:not(.ledger-sheet) tbody td,
.sheet-card .table:not(.ledger-sheet) tfoot td {
    border: 1px solid #dbe2ec;
    padding: 8px 10px;
    vertical-align: middle;
    background: #fff;
}

.sheet-panel .table:not(.ledger-sheet) tbody tr:hover > td,
.sheet-panel .table:not(.ledger-sheet) tbody tr:hover > th,
.sheet-card .table:not(.ledger-sheet) tbody tr:hover > td,
.sheet-card .table:not(.ledger-sheet) tbody tr:hover > th {
    background: #edf2f6;
}

.form-control,
.form-select,
.input-group-text {
    border-color: var(--sheet-border);
    color: var(--sheet-text);
    background: #fff;
}

.form-control:focus,
.form-select:focus {
    border-color: #6b7280;
    box-shadow: 0 0 0 1px rgba(17, 24, 39, 0.22);
}

.input-group-text {
    background: #f8fafc;
}

.btn {
    border-radius: 8px;
}

.btn-primary {
    background: var(--sheet-accent);
    border-color: var(--sheet-accent);
}

.btn-primary:hover,
.btn-primary:focus {
    background: #526b84;
    border-color: #526b84;
}

.btn-outline-primary {
    color: var(--sheet-accent);
    border-color: #9eb0c2;
}

.btn-outline-primary:hover,
.btn-outline-primary:focus {
    background: var(--sheet-accent-soft);
    color: #466079;
    border-color: #8ea2b6;
}

.btn-outline-secondary {
    color: #5f6b7a;
    border-color: #c4ccd6;
}

.btn-outline-secondary:hover,
.btn-outline-secondary:focus {
    background: #eef2f6;
    color: #4c5a69;
    border-color: #b7c2ce;
}

.btn-outline-danger {
    color: #9c6e6e;
    border-color: #d6b3b3;
}

.btn-outline-danger:hover,
.btn-outline-danger:focus {
    background: #f4e7e7;
    color: #875b5b;
    border-color: #cda3a3;
}

.btn-outline-success {
    color: #5e7d69;
    border-color: #b7ccb8;
}

.btn-outline-success:hover,
.btn-outline-success:focus {
    background: #ebf3ec;
    color: #4f6c59;
    border-color: #aabfad;
}

.btn-outline-warning {
    color: #8b7650;
    border-color: #d8c9a7;
}

.btn-outline-warning:hover,
.btn-outline-warning:focus {
    background: #f6f1e7;
    color: #756242;
    border-color: #ccb98f;
}

.badge {
    font-weight: 600;
    letter-spacing: 0.01em;
}

.badge.bg-primary,
.bg-primary {
    background-color: var(--sheet-accent) !important;
}

.badge.bg-info,
.bg-info {
    background-color: #d9e5ef !important;
    color: #47617b !important;
}

.badge.bg-success,
.bg-success {
    background-color: #dce9df !important;
    color: #4e6d59 !important;
}

.badge.bg-warning,
.bg-warning {
    background-color: #efe7d4 !important;
    color: #7a6640 !important;
}

.badge.bg-danger,
.bg-danger {
    background-color: #ead8d8 !important;
    color: #8a5f5f !important;
}

.badge.bg-secondary,
.bg-secondary {
    background-color: #e5eaf0 !important;
    color: #556273 !important;
}

.alert {
    border: 1px solid var(--sheet-border);
    background: #fbfcfe;
    color: var(--sheet-subtext);
}

.sheet-filter-card .card-body {
    padding: 0;
}

.sheet-form-grid {
    --bs-gutter-x: 0;
    --bs-gutter-y: 0;
    margin: 0;
}

.sheet-form-grid > [class*="col-"] {
    padding: 12px 14px;
    background: #fff;
    border-top: 1px solid var(--sheet-border);
    border-right: 1px solid var(--sheet-border);
}

.sheet-form-grid > [class*="col-"]:last-child {
    border-right: 0;
}

.sheet-form-grid .form-label {
    display: block;
    margin-bottom: 0.4rem;
    font-size: 12px;
    color: var(--sheet-subtext);
}

.sheet-form-grid .form-text,
.sheet-form-grid .small.text-muted {
    color: var(--sheet-subtext) !important;
}

.sheet-form-grid .sheet-meta {
    min-height: 38px;
    display: flex;
    align-items: center;
    gap: 8px;
    flex-wrap: wrap;
}

.sheet-empty {
    border: 1px solid var(--sheet-border);
    background: #fff;
    border-radius: 10px;
    box-shadow: 0 6px 18px rgba(15, 23, 42, 0.05);
}

@media (max-width: 991.98px) {
    .sheet-form-grid > [class*="col-"] {
        border-right: 0;
    }
}

.pagination .page-link {
    border-color: var(--sheet-border);
    color: #4a6178;
    background: #fff;
}

.pagination .page-item.active .page-link {
    background: var(--sheet-accent);
    border-color: var(--sheet-accent);
}

.modal-content {
    border: 1px solid var(--sheet-border);
    border-radius: 12px;
    box-shadow: 0 18px 40px rgba(15, 23, 42, 0.16);
}

.modal-header,
.modal-footer {
    background: #f8fafc;
    border-color: var(--sheet-border);
}

/* Scrollbar Styling for Webkit */
::-webkit-scrollbar {
    width: 12px;
    height: 12px;
}

::-webkit-scrollbar-track {
    background: #f1f1f1;
}

::-webkit-scrollbar-thumb {
    background: #aeb8c4;
    border: 2px solid #f1f1f1;
    border-radius: 6px;
}

::-webkit-scrollbar-thumb:hover {
    background: #8795a5;
}