:root {
        --pico-font-size: 93.75%;
        --pico-block-spacing-vertical: 0.5rem;
        --pico-block-spacing-horizontal: 0.5rem;
        --pico-form-element-spacing-vertical: 0.4rem;
        --pico-form-element-spacing-horizontal: 0.6rem;
        --pico-typography-spacing-vertical: 0.75rem;
        font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen,
                     Ubuntu, Cantarell, "Helvetica Neue", Arial, sans-serif;
    }

    /* Twin-specific theme CSS is generated by configure_dashboard() */
    /* Map Pico vars to dashboard vars — :root bumps specificity to (0,2,0)
       to beat Pico's :root:not([data-theme=dark]) */
    :root[data-dashboard] {
        --pico-primary: var(--dashboard-primary);
        --pico-primary-hover: var(--dashboard-primary-dark);
        --pico-primary-background: var(--dashboard-primary);
        --pico-primary-hover-background: var(--dashboard-primary-dark);
        --pico-primary-border: var(--dashboard-primary);
        --pico-primary-hover-border: var(--dashboard-primary-dark);
        --pico-primary-focus: var(--dashboard-primary-light);
        --pico-primary-underline: var(--dashboard-primary-light);
        --pico-primary-inverse: #fff;
    }
    /* Dark mode — lighter hover for contrast on dark bg */
    [data-theme="dark"][data-dashboard] {
        --pico-primary: var(--dashboard-primary-light);
        --pico-primary-hover: var(--dashboard-primary);
        --pico-primary-background: var(--dashboard-primary);
        --pico-primary-hover-background: var(--dashboard-primary-dark);
        --pico-primary-border: var(--dashboard-primary-light);
        --pico-primary-hover-border: var(--dashboard-primary);
        --pico-primary-focus: var(--dashboard-primary-light);
        --pico-primary-underline: var(--dashboard-primary-light);
        --pico-primary-inverse: #fff;
    }
    /* --- Typography --- */
    h1, h2, h3 { letter-spacing: -0.01em; }
    h1 { --pico-typography-spacing-vertical: 1rem; }

    /* --- Nav bar --- */
    .dashboard-nav {
        position: sticky; top: 0; z-index: 100;
        display: flex; align-items: center; justify-content: space-between;
        padding: 0.6rem 1.2rem;
        border-bottom: 2px solid var(--dashboard-primary);
        background: var(--pico-background-color);
        backdrop-filter: blur(8px);
    }
    .dashboard-nav .brand {
        font-size: 1.1rem; font-weight: 700; letter-spacing: -0.02em;
        background: linear-gradient(135deg, var(--dashboard-gradient-start),
                                             var(--dashboard-gradient-end));
        -webkit-background-clip: text; -webkit-text-fill-color: transparent;
        background-clip: text; color: transparent;
    }
    .dashboard-nav .nav-links { display: flex; align-items: center; gap: 0; }
    .dashboard-nav .nav-group { display: flex; align-items: center; gap: 1rem; }
    .dashboard-nav .nav-group + .nav-group::before {
        content: ""; display: block;
        width: 1px; height: 1.2rem; margin: 0 1rem;
        background: currentColor; opacity: 0.2;
    }
    .dashboard-nav .nav-links a {
        font-size: 0.85rem; text-decoration: none; opacity: 0.7;
    }
    .dashboard-nav .nav-links a:hover { opacity: 1; }
    .nav-user { font-size: 0.8rem; opacity: 0.6; white-space: nowrap; }
    #theme-toggle {
        background: var(--dashboard-surface);
        border: 1.5px solid var(--dashboard-primary);
        border-radius: 8px; padding: 0.3rem 0.55rem; cursor: pointer;
        font-size: 1rem; line-height: 1;
        color: var(--dashboard-primary);
    }
    #theme-toggle:hover {
        background: var(--dashboard-surface-hover);
    }
    /* Show correct icon per theme */
    .icon-sun { display: none; }
    .icon-moon { display: inline; }
    [data-theme="dark"] .icon-sun { display: inline; }
    [data-theme="dark"] .icon-moon { display: none; }

    /* --- Cards / articles --- */
    article {
        position: relative; overflow: hidden;
        padding: 1rem; border-radius: 12px;
        box-shadow: 0 1px 3px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
        transition: transform 0.15s ease, box-shadow 0.15s ease;
    }
    article:hover {
        box-shadow: 0 4px 12px rgba(0,0,0,0.1), 0 2px 4px rgba(0,0,0,0.06);
    }
    [data-theme="dark"] article:hover {
        box-shadow: 0 4px 12px rgba(255,255,255,0.08), 0 2px 4px rgba(255,255,255,0.05);
    }
    .card-primary { border: 2px solid var(--pico-primary-background); }

    /* --- Hub pages: responsive grid of navigation cards --- */
    .hub-grid { display: grid; gap: 20px;
                grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); }
    .hub-grid article { margin-bottom: 0; }
    .hub-grid article h3 { margin-top: 0; }
    .card-disabled { opacity: 0.6; }
    .btn { display: inline-block; padding: 8px 16px;
           background: var(--pico-primary-background);
           color: var(--pico-primary-inverse);
           text-decoration: none; border-radius: 4px; margin-right: 8px; }
    .btn:hover { opacity: 0.85; text-decoration: none; }
    .btn-disabled { display: inline-block; padding: 8px 16px; background: #ccc;
                    color: #666; border-radius: 4px; font-size: 0.9em; }

    /* Card background illustrations */
    .card-bg::after {
        content: ''; position: absolute;
        top: -10%; bottom: -10%; left: 0; right: -3%;
        pointer-events: none; z-index: 0;
        background-size: auto 100%;
        background-position: center right;
        background-repeat: no-repeat;
        -webkit-mask-image: linear-gradient(to right,
            transparent 15%, black 65%);
        mask-image: linear-gradient(to right,
            transparent 15%, black 65%);
    }
    .card-bg > * { position: relative; z-index: 1; }
    html:not([data-theme="dark"]) .card-bg::after {
        filter: invert(1);
    }
    .card-bg-chart::after {
        background-image: url(/static/cards/line_chart.svg);
    }
    .card-bg-sun::after {
        background-image: url(/static/cards/sun.svg);
    }
    .card-bg-growth::after {
        background-image: url(/static/cards/growth.svg);
    }
    .card-bg-status::after {
        background-image: url(/static/cards/status.svg);
    }
    .card-bg-multi-height::after {
        background-image: url(/static/cards/multi_height.svg);
    }

    /* --- Stats cards --- */
    .stats-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 15px; }
    .stats-grid.cols-4 { grid-template-columns: repeat(4, 1fr); }
    .stats-grid.cols-5 { grid-template-columns: repeat(5, 1fr); }
    .stats-grid.cols-auto { grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); }
    .stats-grid article {
        text-align: center; margin-bottom: 0;
        background: linear-gradient(135deg, var(--dashboard-gradient-start),
                                             var(--dashboard-gradient-end));
        color: #fff; border: none;
    }
    .stats-grid article small { color: rgba(255,255,255,0.85); }
    .stat-value { font-size: 1.6em; font-weight: 800; color: #fff; }
    .success { color: #16a34a !important; }
    .warning { color: #f59e0b !important; }
    [data-theme="dark"] .success { color: #4ade80 !important; }
    [data-theme="dark"] .warning { color: #fbbf24 !important; }

    /* --- Date filter --- */
    .date-filter {
        padding: 0.75rem 1rem;
        border-left: 3px solid var(--dashboard-primary);
        background: var(--dashboard-surface);
        border-radius: 0 12px 12px 0;
    }
    .date-filter form { margin-bottom: 0; }
    .date-presets { display: flex; gap: 4px; margin-bottom: 8px; flex-wrap: wrap; }
    .date-presets button { width: auto; padding: 0.25rem 0.75rem; margin-bottom: 0; }
    .date-presets button:hover { transform: translateY(-1px); }
    .date-inputs { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; }
    .date-inputs label { margin-bottom: 0; }
    .date-inputs button { width: auto; padding: 0.25rem 0.75rem; margin-bottom: 0; }

    /* --- Explore tabs --- */
    .explore-tabs .tab-buttons {
        display: flex; gap: 0.25rem;
        border-bottom: 1px solid var(--pico-muted-border-color);
        margin-bottom: 1rem;
    }
    .explore-tabs .tab-buttons button {
        background: transparent; border: 0; border-radius: 0;
        border-bottom: 2px solid transparent;
        color: var(--pico-muted-color); cursor: pointer;
        margin: 0 0 -1px 0; padding: 0.5rem 0.9rem;
        width: auto; font-weight: 600;
    }
    .explore-tabs .tab-buttons button:hover { color: var(--pico-color); }
    .explore-tabs .tab-buttons button[aria-selected="true"] {
        color: var(--dashboard-primary);
        border-bottom-color: var(--dashboard-primary);
    }

    /* --- Tables --- */
    /* Grouped tables: hide content of merged duplicate cells without
       collapsing the cell itself (keeps row borders & widths consistent). */
    td.cell-merged > * { display: none; }

    :root[data-dashboard] thead {
        background: transparent;
    }
    :root[data-dashboard] thead th {
        background: transparent;
        color: var(--dashboard-primary);
        --pico-color: var(--dashboard-primary);
        border-bottom: 2px solid var(--dashboard-primary);
        user-select: none;
        font-weight: 700;
    }
    thead th[onclick]:hover { opacity: 0.8; }
    tbody tr { transition: background 0.1s ease; }
    tbody tr:hover { background: var(--dashboard-surface-hover); }

    /* --- Buttons --- */
    button, [type="submit"] { transition: transform 0.1s ease; }
    button:hover, [type="submit"]:hover { transform: translateY(-1px); }

    /* --- Back link & logo --- */
    .back { margin-bottom: 20px; }
    .logo { margin-bottom: 20px; }
    .logo img { max-height: 80px; }

    /* --- Footer --- */
    footer {
        margin-top: 40px; padding-top: 20px;
        border-top: 1px solid var(--pico-muted-border-color);
        display: flex; align-items: center; justify-content: space-between; gap: 16px;
    }
    .footer-logo { max-height: 60px; transition: opacity 0.15s ease; }
    .footer-logo:hover { opacity: 0.7; }
    .footer-links { display: flex; align-items: center; gap: 14px; }
    .footer-icon {
        display: inline-flex; color: var(--pico-muted-color);
        transition: color 0.15s ease, transform 0.15s ease;
    }
    .footer-icon:hover { color: var(--dashboard-primary); transform: translateY(-1px); }

    /* --- Collapsible date filter --- */
    .date-filter-collapsible {
        padding: 0;
        margin-bottom: 0.5rem;
        border: none;
        box-shadow: none;
    }
    .date-filter-collapsible summary {
        cursor: pointer;
        font-size: 0.85rem;
        font-weight: 600;
        color: var(--dashboard-primary);
        padding: 0.4rem 0.75rem;
        border-left: 3px solid var(--dashboard-primary);
        background: var(--dashboard-surface);
        border-radius: 0 8px 8px 0;
    }
    .date-filter-collapsible[open] summary {
        margin-bottom: 0;
        border-radius: 0 8px 0 0;
    }
    .date-filter-collapsible .date-filter {
        border-radius: 0 0 12px 0;
        margin-bottom: 0;
        padding: 0.4rem 0.5rem;
    }
    .sensor-panel .date-filter-collapsible {
        margin-bottom: 0.5rem;
    }
    .sensor-panel .date-presets {
        flex-wrap: wrap;
        gap: 2px;
    }
    .sensor-panel .date-presets button {
        padding: 0.15rem 0.5rem;
        font-size: 0.75rem;
    }
    .sensor-panel .date-inputs {
        display: flex;
        align-items: center;
        gap: 2px;
    }
    .sensor-panel .date-inputs input[type="date"] {
        font-size: 0.72rem;
        padding: 0.15rem 0.25rem;
        flex: 1;
        min-width: 0;
    }
    .sensor-panel .date-sep {
        font-size: 0.75rem;
        opacity: 0.5;
        flex-shrink: 0;
    }
    .date-filter-collapsible:hover {
        transform: none;
        box-shadow: none;
    }

    /* --- Unified chart layout --- */
    .chart-layout {
        display: flex;
        gap: 0;
        min-height: 600px;
    }
    body:has(.chart-layout) main {
        max-width: none;
        padding-left: 0.5rem;
        padding-right: 0.5rem;
    }
    .sensor-panel {
        width: 260px;
        min-width: 260px;
        border-right: 2px solid var(--dashboard-primary);
        padding: 0.75rem;
        overflow-y: auto;
        max-height: 80vh;
        background: var(--dashboard-surface);
        transition: width 0.2s, min-width 0.2s, padding 0.2s;
    }
    .sensor-panel.collapsed {
        width: 0;
        min-width: 0;
        padding: 0;
        overflow: hidden;
        border-right: none;
    }
    .sensor-panel h4 {
        margin: 0 0 0.5rem 0;
        font-size: 0.9rem;
        color: var(--dashboard-primary);
    }
    .chart-main {
        flex: 1;
        min-width: 0;
        padding: 0 0.5rem;
    }
    .panel-toggle {
        font-size: 0.8rem;
        padding: 0.2rem 0.6rem;
        margin-bottom: 0.5rem;
        cursor: pointer;
        width: auto;
    }

    /* Measurement groups in side panel */
    .sensor-group {
        margin-bottom: 0.5rem;
    }
    .sensor-group summary {
        font-size: 0.82rem;
        font-weight: 600;
        cursor: pointer;
        padding: 0.15rem 0;
        color: var(--dashboard-primary);
    }
    .sensor-item {
        display: flex;
        align-items: center;
        gap: 0.3rem;
        padding: 0.1rem 0 0.1rem 0.5rem;
        font-size: 0.78rem;
    }
    .sensor-item .cb-label {
        margin: 0;
        padding: 0;
        font-size: 0.7rem;
        font-weight: 600;
        opacity: 0.6;
        cursor: pointer;
        display: inline-flex;
        align-items: center;
        gap: 1px;
    }
    .sensor-item .cb-label:has(:checked) {
        opacity: 1;
        color: var(--dashboard-primary);
    }
    .sensor-item input[type="checkbox"] {
        margin: 0;
        transform: scale(0.8);
    }
    .sensor-item .device-name {
        font-size: 0.78rem;
        white-space: nowrap;
        overflow: hidden;
        text-overflow: ellipsis;
        cursor: pointer;
    }
    .sensor-item .device-name:hover {
        color: var(--dashboard-primary);
    }
    .group-badge {
        font-size: 0.7rem;
        font-weight: 700;
        color: var(--dashboard-primary);
    }
    .sensor-panel h4 {
        display: flex;
        justify-content: space-between;
        align-items: center;
    }
    .clear-btn {
        font-size: 0.7rem;
        opacity: 0.5;
        text-decoration: none;
        font-weight: 400;
    }
    .clear-btn:hover {
        opacity: 1;
    }
    .group-toggle {
        display: flex;
        margin-bottom: 0.5rem;
        border-radius: 6px;
        overflow: hidden;
        border: 1px solid var(--dashboard-primary);
    }
    .group-btn, .label-btn, .agg-btn, .ct-btn {
        flex: 1;
        font-size: 0.72rem;
        padding: 0.25rem 0.3rem;
        margin-bottom: 0;
        cursor: pointer;
        border: none;
        border-radius: 0;
        background: transparent;
        color: var(--dashboard-primary);
        transition: background 0.15s, color 0.15s;
    }
    .group-btn:not(:last-child), .label-btn:not(:last-child),
    .agg-btn:not(:last-child), .ct-btn:not(:last-child) {
        border-right: 1px solid var(--dashboard-primary);
    }
    .group-btn.active, .label-btn.active, .agg-btn.active, .ct-btn.active {
        background: var(--dashboard-primary);
        color: #fff;
    }
    .group-btn:not(.active):hover, .label-btn:not(.active):hover,
    .agg-btn:not(.active):hover, .ct-btn:not(.active):hover {
        background: color-mix(in srgb, var(--dashboard-primary) 12%, transparent);
    }
    /* Y-Left / Y-Right axis tabs: an underline tab strip, deliberately
       distinct from the filled segmented toggles below it. */
    .axis-tabs {
        display: flex;
        gap: 0.25rem;
        margin-bottom: 0.6rem;
        border-bottom: 2px solid
            color-mix(in srgb, var(--dashboard-primary) 25%, transparent);
    }
    .axis-tab {
        flex: 1;
        padding: 0.4rem 0.5rem;
        cursor: pointer;
        border: none;
        background: transparent;
        color: var(--dashboard-primary);
        font-size: 0.8rem;
        border-bottom: 2px solid transparent;
        margin-bottom: -2px;
        opacity: 0.55;
        transition: opacity 0.15s, border-color 0.15s;
    }
    .axis-tab.active {
        border-bottom-color: var(--dashboard-primary);
        font-weight: 700;
        opacity: 1;
    }
    .axis-tab:not(.active):hover { opacity: 0.85; }
    .ct-icon {
        width: 11px;
        height: 11px;
        vertical-align: -1px;
        margin-right: 4px;
        opacity: 0.85;
    }
    .bucket-slider {
        font-size: 0.75rem;
        margin: 0.3rem 0;
    }
    .bucket-slider input[type="range"] {
        width: 100%;
        margin: 0.2rem 0 0;
    }
    .band-toggle {
        display: flex;
        align-items: center;
        gap: 0.4rem;
        font-size: 0.8rem;
        margin: 0.4rem 0 0;
        cursor: pointer;
    }
    .band-toggle input[type="checkbox"] {
        margin: 0;
        width: auto;
    }
    .band-hint {
        display: block;
        font-size: 0.7rem;
        opacity: 0.65;
        margin: 0 0 0.3rem 1.4rem;
    }
    /* "Show but disable": the band only applies to a true range (an active
       aggregation other than SUM), so grey it out when it cannot apply. */
    .band-toggle.disabled {
        opacity: 0.45;
        cursor: not-allowed;
    }
    /* --- Ideal range section --- */
    .ideal-range-section {
        margin-top: 0.6rem;
    }
    .ideal-range-section h4 {
        font-size: 0.82rem;
        font-weight: 600;
        margin: 0.2rem 0 0.25rem;
        color: var(--dashboard-primary);
    }
    .ideal-range-inputs {
        display: flex;
        align-items: center;
        gap: 0.3rem;
    }
    .ideal-input {
        font-size: 0.75rem;
        padding: 0.15rem 0.3rem;
        flex: 1;
        min-width: 0;
        width: auto;
    }
    .ideal-range-section.disabled {
        opacity: 0.45;
        pointer-events: none;
    }
    .advanced-options {
        margin-top: 0.6rem;
    }
    .advanced-options > summary {
        font-size: 0.82rem;
        font-weight: 600;
        color: var(--dashboard-primary);
        cursor: pointer;
    }
    .advanced-options .advanced-inner {
        margin-top: 0.4rem;
        display: flex;
        flex-direction: column;
        gap: 0.5rem;
    }
    .advanced-toggle {
        display: flex;
        align-items: center;
        gap: 0.4rem;
        font-size: 0.8rem;
        margin: 0;
        cursor: pointer;
    }
    .advanced-toggle input[type="checkbox"] {
        margin: 0;
        width: auto;
        appearance: auto;
        -webkit-appearance: checkbox;
        accent-color: var(--dashboard-primary);
        transform: scale(1.05);
        transform-origin: center;
    }
    .chart-warning {
        margin: 0.35rem 0 0.5rem;
        padding: 0.45rem 0.65rem;
        border: 1px solid rgba(245, 158, 11, 0.45);
        background: rgba(245, 158, 11, 0.08);
        border-radius: 8px;
        font-size: 0.82rem;
    }
    .axis-split-toggle {
        display: flex;
        align-items: center;
        gap: 0.4rem;
        font-size: 0.8rem;
        margin: 0.5rem 0 0.3rem;
        cursor: pointer;
    }
    .axis-split-toggle input[type="checkbox"] {
        margin: 0;
    }
    #axis-controls-split h4 {
        margin: 0.6rem 0 0.2rem;
    }
    .unit-badge {
        font-size: 0.65rem;
        opacity: 0.5;
        margin-left: 2px;
    }
    .sensor-item.active {
        background: var(--dashboard-surface-hover);
        border-radius: 4px;
    }
    #chart-area {
        min-height: 500px;
    }
    .chart-stats {
        font-size: 0.82rem;
        opacity: 0.7;
        margin: 0.25rem 0;
    }
    .truncation-warning {
        color: #f59e0b;
        font-weight: 600;
    }
    [data-theme="dark"] .truncation-warning {
        color: #fbbf24;
    }
    .chart-empty {
        display: flex;
        align-items: center;
        justify-content: center;
        min-height: 400px;
        opacity: 0.5;
        font-size: 1.1rem;
    }

    /* --- Charts: dark mode invert --- */
    [data-theme="dark"] .js-plotly-plot {
        filter: invert(0.88) hue-rotate(180deg);
    }