:root {
    --sidebar-bg: #1e2128;
    --sidebar-width: 220px;
    --page-bg: #f4f5f7;
    --card-bg: #ffffff;
    --border-color: #e5e7eb;
    --text-primary: #111827;
    --text-secondary: #6b7280;
    --nav-active-bg: rgba(255, 255, 255, 0.10);
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background: var(--page-bg);
    color: var(--text-primary);
}

.app-shell {
    display: flex;
    min-height: 100vh;
}

.sidebar {
    width: var(--sidebar-width);
    background: var(--sidebar-bg);
    color: #fff;
    display: flex;
    flex-direction: column;
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    z-index: 100;
    transition: width 0.25s ease;
    overflow: hidden;
    flex-shrink: 0;
}

.sidebar.collapsed {
    width: 0;
}

.sidebar-brand {
    padding: 20px 16px;
    font-size: 16px;
    font-weight: 600;
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.sidebar-nav {
    flex: 1;
    padding: 12px 8px;
}

.sidebar-nav .nav-link {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 12px;
    color: rgba(255, 255, 255, 0.75);
    text-decoration: none;
    border-radius: 6px;
    margin-bottom: 4px;
    font-size: 14px;
}

.sidebar-nav .nav-link:hover {
    color: #fff;
    background: rgba(255, 255, 255, 0.05);
}

.sidebar-nav .nav-link.active {
    color: #fff;
    background: var(--nav-active-bg);
}

.sidebar-footer {
    padding: 16px;
    border-top: 1px solid rgba(255, 255, 255, 0.08);
    font-size: 13px;
}

.sidebar-footer .user-name {
    font-weight: 500;
    margin-bottom: 2px;
}

.sidebar-footer .user-role {
    color: rgba(255, 255, 255, 0.55);
    font-size: 12px;
    text-transform: capitalize;
    margin-bottom: 12px;
}

.main-content {
    margin-left: var(--sidebar-width);
    flex: 1;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    transition: margin-left 0.25s ease;
}

.main-content.expanded {
    margin-left: 0;
}

.top-bar-left {
    display: flex;
    align-items: center;
    gap: 12px;
}

.sidebar-toggle-btn {
    background: none;
    border: none;
    padding: 4px 8px;
    color: var(--text-primary);
    font-size: 20px;
    line-height: 1;
    cursor: pointer;
    border-radius: 6px;
}

.sidebar-toggle-btn:hover {
    background: #f3f4f6;
}

.description-cell {
    max-width: 300px;
    word-wrap: break-word;
    word-break: break-word;
    white-space: normal;
    overflow-wrap: break-word;
}

.top-bar {
    background: #fff;
    border-bottom: 1px solid var(--border-color);
    padding: 16px 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.top-bar-title {
    font-size: 18px;
    font-weight: 600;
    margin: 0;
}

.breadcrumb-text {
    font-size: 13px;
    color: var(--text-secondary);
    margin-top: 2px;
}

.page-content {
    padding: 24px;
    flex: 1;
}

.card-panel {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 20px;
}

.stat-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
    margin-bottom: 24px;
}

.stat-card {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 20px;
    display: flex;
    align-items: center;
    gap: 16px;
}

.stat-card .stat-icon {
    width: 44px;
    height: 44px;
    border-radius: 8px;
    background: #f3f4f6;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
    color: var(--text-secondary);
}

.stat-card .stat-label {
    font-size: 13px;
    color: var(--text-secondary);
    margin-bottom: 4px;
}

.stat-card .stat-value {
    font-size: 28px;
    font-weight: 600;
    line-height: 1;
}

.btn-primary-dark {
    background: var(--sidebar-bg);
    border-color: var(--sidebar-bg);
    color: #fff;
}

.btn-primary-dark:hover,
.btn-primary-dark:focus {
    background: #2a2f38;
    border-color: #2a2f38;
    color: #fff;
}

.btn-secondary-outline {
    background: #fff;
    border: 1px solid var(--border-color);
    color: var(--text-primary);
}

.btn-secondary-outline:hover {
    background: #f9fafb;
    border-color: var(--border-color);
    color: var(--text-primary);
}

.table-card table {
    margin-bottom: 0;
}

.table-card thead th {
    background: #f9fafb;
    font-size: 12px;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    color: var(--text-secondary);
    font-weight: 600;
    border-bottom: 1px solid var(--border-color);
}

.table-card tbody td {
    font-size: 14px;
    vertical-align: middle;
}

.table-card tbody tr:hover {
    background: #f3f4f6;
}

.form-section-title {
    font-size: 15px;
    font-weight: 600;
    margin-bottom: 16px;
    padding-bottom: 8px;
    border-bottom: 1px solid var(--border-color);
}

.auth-page {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--page-bg);
}

.auth-card {
    width: 100%;
    max-width: 400px;
    background: #fff;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 32px;
}

.auth-card h1 {
    font-size: 20px;
    font-weight: 600;
    margin-bottom: 8px;
}

.auth-card p {
    color: var(--text-secondary);
    font-size: 14px;
    margin-bottom: 24px;
}

.submodule-row {
    display: grid;
    grid-template-columns: 1fr 120px auto;
    gap: 12px;
    align-items: start;
    margin-bottom: 12px;
}

.submodule-header-row {
    display: grid;
    grid-template-columns: 1fr 120px auto;
    gap: 12px;
    margin-bottom: 8px;
    font-size: 12px;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    color: var(--text-secondary);
    font-weight: 600;
}

.percentage-total {
    font-weight: 600;
    font-size: 14px;
}

.percentage-total.text-success {
    color: #198754;
}

.percentage-total.text-danger {
    color: #dc3545;
}

.analysis-module-header-row {
    display: grid;
    grid-template-columns: 1fr 160px auto;
    gap: 12px;
    margin-bottom: 8px;
    font-size: 12px;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    color: var(--text-secondary);
    font-weight: 600;
}

.analysis-module-row {
    display: grid;
    grid-template-columns: 1fr 160px auto;
    gap: 12px;
    align-items: start;
    margin-bottom: 12px;
}

.class-chip-container {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
}

.class-chip .class-chip-remove {
    background: none;
    border: none;
    color: #fff;
    padding: 0;
    line-height: 1;
    font-size: 14px;
    cursor: pointer;
}

.detail-tabs .nav-link {
    color: var(--text-secondary);
    font-size: 14px;
}

.detail-tabs .nav-link.active {
    color: var(--text-primary);
    font-weight: 600;
}

.info-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
}

.info-item label {
    display: block;
    font-size: 12px;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    color: var(--text-secondary);
    margin-bottom: 4px;
}

.info-item span {
    font-size: 14px;
}

.percentage-warning {
    color: #dc3545;
    font-size: 13px;
    display: none;
}

.student-row-inactive {
    opacity: 0.6;
}

.sort-link {
    color: inherit;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 4px;
}

.sort-link:hover {
    color: var(--text-primary);
    text-decoration: underline;
}

.table-card thead th .sort-link {
    font-size: inherit;
    font-weight: inherit;
    text-transform: inherit;
    letter-spacing: inherit;
}

.pagination-nav .page-link {
    color: var(--text-primary);
    border-color: var(--border-color);
    font-size: 14px;
}

.pagination-nav .page-item.active .page-link {
    background: var(--sidebar-bg);
    border-color: var(--sidebar-bg);
    color: #fff;
}

.pagination-nav .page-link:hover {
    background: #f3f4f6;
}

.analysis-result-layout {
    display: grid;
    grid-template-columns: minmax(0, 2fr) minmax(280px, 1fr);
    gap: 20px;
    align-items: start;
}

.analysis-module-divider {
    background: #f3f4f6;
    padding: 8px 12px;
    border-radius: 6px;
    font-size: 13px;
    font-weight: 600;
    margin: 16px 0 8px;
}

.analysis-question-table thead th {
    font-size: 12px;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    color: var(--text-secondary);
}

.submodule-order-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

.submodule-order-list li {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 16px;
    background: #fff;
    border: 1px solid #e5e7eb;
    border-radius: 8px;
    margin-bottom: 8px;
    cursor: grab;
}

.submodule-order-list .drag-handle {
    color: #9ca3af;
    font-size: 18px;
    cursor: grab;
}

.submodule-order-list .order-number {
    color: #9ca3af;
    font-size: 13px;
    min-width: 24px;
}

.submodule-order-list .submodule-name {
    flex: 1;
    font-size: 14px;
    font-weight: 500;
}

.submodule-order-list .module-badge {
    font-size: 11px;
    background: #f3f4f6;
    padding: 2px 8px;
    border-radius: 4px;
    color: #6b7280;
}

.session-range-table thead th {
    font-size: 12px;
    color: var(--text-secondary);
    font-weight: 600;
}

.session-range-table td {
    vertical-align: middle;
}

.session-ranges-section {
    border-top: 1px solid #e5e7eb;
    padding-top: 8px;
}

.phone-input-group .input-group-text {
    background: #f8fafc;
    color: #1565c0;
    border-color: #e5e7eb;
}

.phone-input-group .form-control {
    letter-spacing: 0.04em;
}

.phone-input-group .form-control.is-valid {
    border-color: #198754;
}

.phone-input-group .form-control.is-invalid {
    border-color: #dc3545;
}

.phone-field-hint {
    font-size: 12px;
    margin-top: 4px;
}

.result-loading-overlay {
    position: fixed;
    inset: 0;
    background: rgba(17, 24, 39, 0.55);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 2000;
}

.result-loading-box {
    background: #111827;
    color: #fff;
    padding: 28px 36px;
    border-radius: 12px;
    text-align: center;
    font-size: 15px;
}

@media (max-width: 992px) {
    .analysis-result-layout {
        grid-template-columns: 1fr;
    }
}