/* pid-pole-zero-bridge — Control Loops lesson (PI v1) */

.tool-page {
    padding-top: var(--ai-space-4);
    padding-bottom: var(--ai-space-8);
}

.ppb-section {
    max-width: none;
    margin: 0 0 var(--ai-space-6);
}

.ppb-lead {
    font-size: 1.02rem;
    line-height: 1.65;
    color: #1e293b;
    margin-bottom: var(--ai-space-3);
}

.ppb-section mjx-container[display="true"] {
    display: block;
    margin: var(--ai-space-3) 0 var(--ai-space-4);
    padding: 14px 20px;
    max-width: 100%;
    overflow-x: auto;
    background: #fff;
    border: 1px solid #e2e8f0;
    border-radius: var(--ai-radius-md);
    box-shadow: 0 1px 2px rgba(15, 23, 42, 0.04);
}

.ppb-split {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--ai-space-5);
    align-items: start;
    margin-top: var(--ai-space-3);
}

.ppb-split-prose {
    min-width: 0;
}

.ppb-split-viz {
    min-width: 0;
    position: sticky;
    top: 12px;
}

.ppb-diagram-wrap {
    margin: 0;
    padding: 12px;
    background: #fff;
    border: 1px solid #e2e8f0;
    border-radius: var(--ai-radius-lg);
    box-shadow: 0 1px 3px rgba(15, 23, 42, 0.05);
}

.ppb-diagram-wrap object,
.ppb-diagram-wrap img {
    display: block;
    width: 100%;
    max-width: 400px;
    margin: 0 auto;
}

.ppb-diagram-wrap figcaption {
    margin-top: 10px;
    font-size: 0.84rem;
    color: var(--ai-gray-600);
    line-height: 1.45;
    text-align: center;
}

.ppb-diagram-row {
    display: grid;
    grid-template-columns: minmax(200px, 0.95fr) minmax(220px, 1.05fr);
    gap: var(--ai-space-3);
    align-items: start;
}

.ppb-diagram-eqs {
    font-size: 0.84rem;
    line-height: 1.45;
    color: #334155;
    min-width: 0;
}

.ppb-diagram-eqs h4 {
    margin: 0 0 10px;
    font-size: 0.92rem;
    color: var(--ai-blue-800);
}

.ppb-diagram-eqs mjx-container[display="true"] {
    margin: 6px 0 8px;
    padding: 8px 10px;
    font-size: 0.88em;
}

.ppb-map-label {
    margin: 10px 0 4px;
    font-size: 0.88rem;
    color: var(--ai-blue-800);
}

.ppb-map-label:first-of-type {
    margin-top: 0;
}

.ppb-map-note {
    margin: 0 0 6px;
    font-size: 0.8rem;
    color: #64748b;
    line-height: 1.4;
}

.ppb-d-note {
    margin-top: 8px;
    padding: 10px 12px;
    background: #f8fafc;
    border-left: 3px solid #7c3aed;
    border-radius: 0 var(--ai-radius-sm) var(--ai-radius-sm) 0;
    font-size: 0.8rem;
    line-height: 1.45;
}

.ppb-d-note p {
    margin: 0 0 8px;
}

.ppb-d-note p:last-child {
    margin-bottom: 0;
}

.ppb-quote {
    margin: var(--ai-space-4) 0;
    padding: 14px 16px;
    background: #f8fafc;
    border-left: 3px solid var(--ai-blue-600);
    border-radius: 0 var(--ai-radius-md) var(--ai-radius-md) 0;
    font-size: 0.95rem;
    line-height: 1.6;
    color: #334155;
}

.ppb-ref {
    font-size: 0.86rem;
    color: var(--ai-gray-600);
    margin-top: var(--ai-space-3);
}

.ppb-references {
    margin-top: var(--ai-space-4);
    padding-top: var(--ai-space-4);
    border-top: 1px solid #e2e8f0;
}

.ppb-ref-list {
    margin: 0;
    padding-left: 1.25rem;
    font-size: 0.92rem;
    line-height: 1.6;
    color: #475569;
}

.ppb-ref-list li + li {
    margin-top: var(--ai-space-2);
}

.ppb-dig-deeper {
    margin: var(--ai-space-4) 0;
    padding: 12px 16px;
    background: #fff;
    border: 1px solid #e2e8f0;
    border-radius: var(--ai-radius-md);
}

.ppb-dig-deeper summary {
    cursor: pointer;
    font-weight: 600;
    color: var(--ai-blue-800);
}

.ppb-dig-deeper[open] summary {
    margin-bottom: var(--ai-space-3);
}

.ppb-dig-deeper p {
    margin: 0 0 var(--ai-space-2);
    font-size: 0.92rem;
    line-height: 1.55;
}

.ppb-interactive {
    margin: var(--ai-space-4) 0;
    padding: 16px 18px;
    background: #fff;
    border: 1px solid #cbd5e1;
    border-radius: var(--ai-radius-lg);
    box-shadow: 0 1px 3px rgba(15, 23, 42, 0.05);
}

.ppb-interactive h3 {
    margin: 0 0 var(--ai-space-3);
    font-size: 1.05rem;
    color: var(--ai-blue-800);
}

.ppb-interactive h4 {
    margin: 0 0 var(--ai-space-2);
    font-size: 0.95rem;
    color: var(--ai-blue-800);
}

.ppb-interactive-split {
    display: grid;
    grid-template-columns: minmax(260px, 1fr) minmax(300px, 1.2fr);
    gap: var(--ai-space-4);
    align-items: start;
}

.ppb-interactive-controls {
    min-width: 0;
}

.ppb-interactive-plots {
    min-width: 0;
}

.panel-hint {
    margin: 0 0 12px;
    font-size: 0.86rem;
    color: var(--ai-gray-600);
    line-height: 1.45;
}

.ppb-chart-pane {
    position: relative;
    height: 360px;
}

.ppb-wb-charts {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--ai-space-4);
    margin-top: var(--ai-space-4);
}

.ppb-coords {
    text-align: center;
    font-size: 0.85rem;
    color: var(--ai-gray-600);
    margin-top: 6px;
    min-height: 1.2em;
}

.ppb-bridge {
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    gap: var(--ai-space-3);
    align-items: start;
    margin-bottom: var(--ai-space-3);
}

.ppb-bridge-arrow {
    display: flex;
    align-items: center;
    justify-content: center;
    padding-top: 36px;
    font-size: 1.5rem;
    color: var(--ai-blue-600);
    font-weight: 700;
}

.ppb-panel {
    background: #f8fafc;
    border: 2px solid #e2e8f0;
    border-radius: var(--ai-radius-lg);
    padding: var(--ai-space-3);
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.ppb-panel-active {
    border-color: var(--ai-blue-600);
    box-shadow: 0 0 0 1px rgba(26, 115, 232, 0.25);
}

.ppb-field {
    margin-bottom: var(--ai-space-3);
}

.ppb-field label {
    display: block;
    font-weight: 600;
    font-size: 0.88rem;
    margin-bottom: 4px;
    color: #374151;
}

.ppb-field input[type="number"] {
    width: 100%;
    max-width: 200px;
    padding: 6px 8px;
    border: 1px solid #d1d5db;
    border-radius: var(--ai-radius-sm);
    font-size: 0.95rem;
}

.ppb-field input:disabled {
    background: #f1f5f9;
    color: #94a3b8;
}

.ppb-field .ppb-slider,
.ppb-control-row .ppb-slider {
    display: block;
    width: 100%;
    max-width: 280px;
    margin-top: 6px;
}

.ppb-slider:disabled {
    opacity: 0.45;
    cursor: not-allowed;
}

.ppb-field-row {
    display: flex;
    align-items: center;
    gap: 10px;
}

.ppb-field-row input[type="number"] {
    width: 120px;
    max-width: none;
    flex-shrink: 0;
}

.ppb-toggle {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: var(--ai-space-3);
    font-size: 0.9rem;
    cursor: pointer;
}

.ppb-toggle input {
    width: 16px;
    height: 16px;
    accent-color: var(--ai-blue-600);
}

.ppb-control-row {
    margin-bottom: var(--ai-space-3);
}

.ppb-control-row label {
    display: block;
    font-weight: 600;
    font-size: 0.88rem;
    margin-bottom: 4px;
}

.ppb-control-row input[type="number"] {
    width: 120px;
    margin-right: 8px;
    padding: 6px 8px;
    border: 1px solid #d1d5db;
    border-radius: var(--ai-radius-sm);
}

.ppb-control-row input[type="range"] {
    width: 100%;
    max-width: 280px;
    vertical-align: middle;
}

.ppb-readout {
    padding: 10px 12px;
    background: #eff6ff;
    border-radius: var(--ai-radius-sm);
    font-size: 0.9rem;
    color: #1e40af;
}

.ppb-readout-row {
    display: flex;
    flex-wrap: wrap;
    gap: 16px;
    margin: var(--ai-space-3) 0;
    font-size: 0.9rem;
}

.ppb-guard {
    margin: 0;
    font-size: 0.82rem;
    color: #64748b;
    line-height: 1.35;
    flex: 1;
    min-width: 0;
}

.ppb-eq-block {
    margin: var(--ai-space-2) 0;
    padding: var(--ai-space-3);
    background: #fff;
    border: 1px solid #e5e7eb;
    border-radius: var(--ai-radius-md);
    overflow-x: auto;
}

.ppb-metrics {
    font-size: 0.9rem;
    line-height: 1.55;
    color: #334155;
    margin: var(--ai-space-3) 0;
}

.ppb-type-note {
    padding: 10px 12px;
    background: #fefce8;
    border-left: 3px solid var(--ai-gold);
    border-radius: var(--ai-radius-sm);
}

.ppb-inv-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.88rem;
}

.ppb-inv-table th,
.ppb-inv-table td {
    border: 1px solid #e2e8f0;
    padding: 8px 10px;
    text-align: left;
}

.ppb-inv-table th {
    background: #f1f5f9;
    font-weight: 600;
}

.ppb-inv-flash {
    background: #ecfdf5;
    animation: ppb-flash 0.6s ease;
}

@keyframes ppb-flash {
    from { background: #bbf7d0; }
    to { background: #ecfdf5; }
}

.ppb-inv-empty {
    font-size: 0.88rem;
    color: var(--ai-gray-600);
    margin: 0;
}

.ppb-btn {
    padding: 8px 14px;
    border: 1px solid #d1d5db;
    border-radius: var(--ai-radius-sm);
    background: var(--ai-gray-100);
    font-size: 0.88rem;
    cursor: pointer;
    margin-right: 8px;
}

.ppb-btn:hover {
    background: #e5e7eb;
}

.ppb-btn-primary {
    background: var(--ai-blue-600);
    color: #fff;
    border-color: var(--ai-blue-700);
}

.ppb-btn-primary:hover {
    background: var(--ai-blue-700);
}

.ppb-chart-link-note {
    font-size: 0.85rem;
    color: var(--ai-gray-600);
    margin: 0;
}

.ppb-wb-note {
    font-size: 0.86rem;
    color: var(--ai-gray-600);
    margin: 0 0 var(--ai-space-3);
}

.ppb-future ul {
    margin: 0 0 var(--ai-space-3);
    padding-left: 1.25rem;
    line-height: 1.6;
}

.ppb-s4-fz-row {
    margin-top: var(--ai-space-3);
    padding-top: var(--ai-space-3);
    border-top: 1px solid #e2e8f0;
}

.ppb-demo-fig {
    margin: var(--ai-space-3) 0 var(--ai-space-4);
    max-width: 520px;
}

.ppb-demo-fig img {
    display: block;
    width: 100%;
    height: auto;
}

.ppb-demo-fig figcaption {
    margin-top: 8px;
    font-size: 0.84rem;
    color: var(--ai-gray-600);
    line-height: 1.45;
}

.ppb-tuning-row {
    display: grid;
    grid-template-columns: minmax(280px, 1fr) minmax(380px, 1.35fr);
    gap: var(--ai-space-4);
    align-items: start;
    margin-bottom: var(--ai-space-4);
}

.ppb-tuning-row--full {
    grid-template-columns: 1fr;
}

.ppb-chart-column {
    display: flex;
    flex-direction: column;
    gap: var(--ai-space-2);
    min-width: 0;
}

.ppb-tuning-row > .ppb-chart-pane {
    height: 200px;
}

.ppb-tuning-row .ppb-chart-pane {
    height: 200px;
}

.ppb-chart-pane--comp {
    height: 200px;
}

.ppb-chart-pane--loop {
    height: 200px;
}

.ppb-loop-readout {
    margin-top: 0;
}

.ppb-workbench-foot {
    margin-top: var(--ai-space-4);
    padding-top: var(--ai-space-4);
    border-top: 1px solid #e2e8f0;
}

.ppb-workbench-foot h3 {
    margin: 0 0 var(--ai-space-2);
    font-size: 1rem;
    color: var(--ai-blue-800);
}

.ppb-workbench-foot h3 + h3 {
    margin-top: var(--ai-space-4);
}

.ppb-console-block .panel-hint {
    margin-bottom: 10px;
}

.ppb-console-block mjx-container[display="true"] {
    margin: 8px 0 10px;
    padding: 10px 14px;
    font-size: 0.92em;
}

.ppb-console-block {
    background: #f8fafc;
    border: 1px solid #e2e8f0;
    border-radius: var(--ai-radius-lg);
    padding: 14px 16px;
}

.ppb-console-head {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    margin-bottom: 12px;
    flex-wrap: wrap;
}

.ppb-console-head h4 {
    margin: 0;
    font-size: 0.95rem;
    color: var(--ai-blue-800);
}

.ppb-toggles {
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
}

.ppb-toggles .ppb-toggle {
    margin: 0;
}

.ppb-console-grid {
    display: grid;
    gap: 10px;
    margin-bottom: 10px;
}

.ppb-console-grid--pid {
    grid-template-columns: repeat(3, 1fr);
}

.ppb-console-grid--pz {
    grid-template-columns: 1fr auto 1fr;
    align-items: end;
}

.ppb-console-grid--plant {
    grid-template-columns: repeat(3, 1fr);
}

.ppb-panel-inline {
    padding: 10px;
    margin: 0;
}

.ppb-bridge-arrow--inline {
    padding: 0 0 28px;
    font-size: 1.2rem;
}

.ppb-ratio-readout {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 8px 10px;
    padding: 10px 12px;
    background: #eff6ff;
    border-radius: var(--ai-radius-sm);
    font-size: 0.84rem;
    color: #1e3a8a;
    margin-bottom: 8px;
    min-height: 56px;
}

.ppb-ratio-slot {
    white-space: nowrap;
}

.ppb-ratio-label {
    color: #475569;
}

.ppb-d-filter-slot {
    min-height: 36px;
}

.ppb-toggle--d-filter {
    margin: 0;
}

.ppb-toggle--disabled {
    opacity: 0.45;
    cursor: not-allowed;
}

.ppb-preset-btns {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
}

.ppb-btn-small {
    padding: 5px 10px;
    font-size: 0.8rem;
    margin: 0;
}

.ppb-chart-stack {
    display: flex;
    flex-direction: column;
    gap: var(--ai-space-3);
}



#ppb-diagram .ppb-line { stroke: #334155; stroke-width: 1.5; fill: none; }
#ppb-diagram .ppb-arrow { fill: #334155; }

@media (max-width: 960px) {
    .ppb-split,
    .ppb-interactive-split,
    .ppb-wb-charts,
    .ppb-tuning-row,
    .ppb-diagram-row,
    .ppb-console-grid--pid,
    .ppb-console-grid--plant,
    .ppb-ratio-readout {
        grid-template-columns: 1fr;
    }

    .ppb-console-grid--pz {
        grid-template-columns: 1fr;
    }

    .ppb-bridge-arrow--inline {
        transform: rotate(90deg);
        padding: 4px 0;
    }

    .ppb-split-viz {
        position: static;
    }

    .ppb-bridge {
        grid-template-columns: 1fr;
    }

    .ppb-bridge-arrow {
        padding: 0;
        transform: rotate(90deg);
    }
}