/* Optional Auras composites layer. Load this after auras.css when you want
   higher-level CSS patterns without pulling in behavior. */
@layer composites {
  :where([data-ui~="master-detail"], auras-master-detail) {
    --master-detail-gap: var(--space-4);
    --master-detail-master-width: 18rem;
    --master-detail-master-padding: var(--space-2);
    --master-detail-master-bg: var(--surface);
    --master-detail-master-border-color: var(--border);
    --master-detail-master-shadow: var(--shadow-sm);
    --master-detail-trigger-radius: var(--radius-md);
    --master-detail-trigger-padding: var(--space-3);
    --master-detail-trigger-border-color: transparent;
    --master-detail-trigger-bg: transparent;
    --master-detail-trigger-bg-hover: var(--surface-raised);
    --master-detail-trigger-bg-active: var(--primary-subtle);
    --master-detail-trigger-border-color-active: color-mix(
      in oklch,
      var(--primary) 38%,
      var(--border)
    );

    display: grid;
    gap: var(--master-detail-gap);
    align-items: start;
  }

  @media (min-width: 48rem) {
    :where([data-ui~="master-detail"], auras-master-detail) {
      grid-template-columns:
        minmax(15rem, var(--master-detail-master-width))
        minmax(0, 1fr);
    }
  }

  :where([data-ui~="master-detail"], auras-master-detail) [data-part="master"] {
    display: grid;
    gap: var(--space-1);
    align-content: start;
    padding: var(--master-detail-master-padding);
    background-color: var(--master-detail-master-bg);
    border: 1px solid var(--master-detail-master-border-color);
    border-radius: var(--radius-lg);
    box-shadow: var(--master-detail-master-shadow);
  }

  :where([data-ui~="master-detail"], auras-master-detail)
    :where(button, a)[data-part="trigger"] {
    inline-size: 100%;
    min-block-size: auto;
    justify-content: flex-start;
    align-items: flex-start;
    flex-direction: column;
    gap: var(--space-1);
    text-align: left;
    background-color: var(--master-detail-trigger-bg);
    border: 1px solid var(--master-detail-trigger-border-color);
    border-radius: var(--master-detail-trigger-radius);
    padding: var(--master-detail-trigger-padding);
    box-shadow: none;
  }

  :where([data-ui~="master-detail"], auras-master-detail)
    :where(button, a)[data-part="trigger"]:hover {
    background-color: var(--master-detail-trigger-bg-hover);
  }

  :where([data-ui~="master-detail"], auras-master-detail)
    [data-part="trigger"][data-active] {
    background-color: var(--master-detail-trigger-bg-active);
    border-color: var(--master-detail-trigger-border-color-active);
  }

  :where([data-ui~="master-detail"], auras-master-detail)
    [data-part="trigger"]
    > :where(p, small) {
    margin: 0;
    color: var(--text-muted);
    font-size: var(--text-sm);
    line-height: var(--leading-normal);
  }

  :where([data-ui~="master-detail"], auras-master-detail)
    [data-part="trigger"][data-active]
    > :where(p, small) {
    color: var(--text);
  }

  :where([data-ui~="master-detail"], auras-master-detail) [data-part="detail"] {
    display: grid;
    min-inline-size: 0;
  }

  :where([data-ui~="master-detail"], auras-master-detail) [data-part="panel"] {
    display: grid;
    gap: var(--space-3);
    min-inline-size: 0;
  }

  :where([data-ui~="master-detail"], auras-master-detail)
    [data-part="panel"][hidden] {
    display: none !important;
  }

  :where([data-ui~="tabs"], auras-tabs) {
    --tabs-gap: var(--space-4);
    --tabs-list-gap: var(--space-2);
    --tabs-list-padding: var(--space-2);
    --tabs-rule-color: var(--border);
    --tabs-trigger-bg: transparent;
    --tabs-trigger-bg-hover: var(--surface-raised);
    --tabs-trigger-bg-active: var(--primary-subtle);
    --tabs-trigger-border-color: transparent;
    --tabs-trigger-border-color-active: color-mix(
      in oklch,
      var(--primary) 38%,
      var(--border)
    );

    display: grid;
    gap: var(--tabs-gap);
  }

  :where([data-ui~="tabs"], auras-tabs) [data-part="tablist"] {
    display: flex;
    flex-wrap: wrap;
    gap: var(--tabs-list-gap);
    align-items: center;
    padding-block-end: var(--tabs-list-padding);
    border-block-end: 1px solid var(--tabs-rule-color);
  }

  :where([data-ui~="tabs"], auras-tabs) :where(button, a)[data-part="trigger"] {
    min-block-size: auto;
    box-shadow: none;
    border: 1px solid var(--tabs-trigger-border-color);
    border-radius: var(--radius-full);
    background-color: var(--tabs-trigger-bg);
    padding-inline: var(--space-3);
    padding-block: var(--space-2);
  }

  :where([data-ui~="tabs"], auras-tabs)
    :where(button, a)[data-part="trigger"]:hover {
    background-color: var(--tabs-trigger-bg-hover);
  }

  :where([data-ui~="tabs"], auras-tabs) [data-part="trigger"][data-active] {
    background-color: var(--tabs-trigger-bg-active);
    border-color: var(--tabs-trigger-border-color-active);
  }

  :where([data-ui~="tabs"], auras-tabs) [data-part="panels"] {
    display: grid;
    min-inline-size: 0;
  }

  :where([data-ui~="tabs"], auras-tabs) [data-part="panel"] {
    display: grid;
    gap: var(--space-3);
    min-inline-size: 0;
  }

  :where([data-ui~="tabs"], auras-tabs) [data-part="panel"][hidden] {
    display: none !important;
  }

  /* ---- Sections (morphing tabs / accordion) ---- */

  :where([data-ui~="sections"], auras-sections) {
    --sections-gap: var(--space-4);
    --sections-trigger-padding: var(--space-3) var(--space-4);
    --sections-trigger-bg: transparent;
    --sections-trigger-bg-hover: var(--surface-raised);
    --sections-trigger-bg-active: var(--primary-subtle);
    --sections-trigger-border-color: transparent;
    --sections-trigger-border-color-active: color-mix(
      in oklch,
      var(--primary) 38%,
      var(--border)
    );
    --sections-trigger-radius: var(--radius-md);
    --sections-panel-padding: var(--space-4);
    --sections-accordion-border-color: var(--border);
    --sections-accordion-icon-size: 1rem;

    display: grid;
    gap: var(--sections-gap);
  }

  /* -- Tabs mode -- */

  :where([data-ui~="sections"], auras-sections)[data-resolved-mode="tabs"] {
    display: grid;
    grid-template-rows: auto 1fr;
    grid-auto-flow: dense;
    grid-auto-columns: max-content;
    gap: var(--sections-gap);
  }

  :where([data-ui~="sections"], auras-sections)[data-resolved-mode="tabs"]
    > [data-part="section"] {
    display: contents;
  }

  :where([data-ui~="sections"], auras-sections)[data-resolved-mode="tabs"]
    [data-part="trigger"] {
    grid-row: 1;
    min-block-size: auto;
    box-shadow: none;
    border: 1px solid var(--sections-trigger-border-color);
    border-radius: var(--radius-full);
    background-color: var(--sections-trigger-bg);
    padding: var(--space-2) var(--space-3);
    cursor: pointer;
    font: inherit;
    font-weight: 500;
    white-space: nowrap;
    transition: background-color var(--transition-fast, 150ms);
  }

  :where([data-ui~="sections"], auras-sections)[data-resolved-mode="tabs"]
    [data-part="trigger"]:hover {
    background-color: var(--sections-trigger-bg-hover);
  }

  :where([data-ui~="sections"], auras-sections)[data-resolved-mode="tabs"]
    [data-part="trigger"][data-active] {
    background-color: var(--sections-trigger-bg-active);
    border-color: var(--sections-trigger-border-color-active);
  }

  :where([data-ui~="sections"], auras-sections)[data-resolved-mode="tabs"]
    [data-part="panel"] {
    grid-row: 2;
    grid-column: 1 / -1;
    display: grid;
    gap: var(--space-3);
    min-inline-size: 0;
  }

  :where([data-ui~="sections"], auras-sections)[data-resolved-mode="tabs"]
    [data-part="panel"][hidden] {
    display: none !important;
  }

  /* -- Accordion mode -- */

  :where([data-ui~="sections"], auras-sections)[data-resolved-mode="accordion"] {
    display: grid;
    gap: 0;
  }

  :where([data-ui~="sections"], auras-sections)[data-resolved-mode="accordion"]
    > [data-part="section"] {
    border: 1px solid var(--sections-accordion-border-color);
    border-radius: var(--sections-trigger-radius);
    background-color: var(--surface);
    overflow: clip;
  }

  :where([data-ui~="sections"], auras-sections)[data-resolved-mode="accordion"]
    > [data-part="section"] + [data-part="section"] {
    margin-block-start: -1px;
    border-start-start-radius: 0;
    border-start-end-radius: 0;
  }

  :where([data-ui~="sections"], auras-sections)[data-resolved-mode="accordion"]
    > [data-part="section"]:has(+ [data-part="section"]) {
    border-end-start-radius: 0;
    border-end-end-radius: 0;
  }

  :where([data-ui~="sections"], auras-sections)[data-resolved-mode="accordion"]
    [data-part="trigger"] {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-3);
    inline-size: 100%;
    min-block-size: auto;
    box-shadow: none;
    border: none;
    border-radius: 0;
    background-color: transparent;
    padding: var(--sections-trigger-padding);
    font: inherit;
    font-weight: 600;
    cursor: pointer;
    user-select: none;
    text-align: start;
    transition: background-color var(--transition-fast, 150ms);
  }

  :where([data-ui~="sections"], auras-sections)[data-resolved-mode="accordion"]
    [data-part="trigger"]:hover {
    background-color: var(--sections-trigger-bg-hover);
  }

  :where([data-ui~="sections"], auras-sections)[data-resolved-mode="accordion"]
    [data-part="trigger"]::after {
    content: "";
    inline-size: var(--sections-accordion-icon-size);
    block-size: var(--sections-accordion-icon-size);
    flex-shrink: 0;
    background-color: currentColor;
    mask-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='currentColor' stroke-width='2'%3E%3Cpath d='m6 9 6 6 6-6'/%3E%3C/svg%3E");
    mask-repeat: no-repeat;
    mask-size: contain;
    transition: transform var(--transition-fast, 150ms);
  }

  :where([data-ui~="sections"], auras-sections)[data-resolved-mode="accordion"]
    [data-part="section"][data-expanded] > [data-part="trigger"] {
    border-block-end: 1px solid
      color-mix(in oklch, var(--sections-accordion-border-color) 60%, transparent);
  }

  :where([data-ui~="sections"], auras-sections)[data-resolved-mode="accordion"]
    [data-part="section"][data-expanded] > [data-part="trigger"]::after {
    transform: rotate(180deg);
  }

  :where([data-ui~="sections"], auras-sections)[data-resolved-mode="accordion"]
    [data-part="panel"] {
    padding: var(--sections-panel-padding);
  }

  :where([data-ui~="sections"], auras-sections)[data-resolved-mode="accordion"]
    [data-part="panel"][hidden] {
    display: none !important;
  }

  @media (prefers-reduced-motion: no-preference) {
    :where([data-ui~="sections"], auras-sections)[data-resolved-mode="accordion"]
      > [data-part="section"] {
      interpolate-size: allow-keywords;
    }

    :where([data-ui~="sections"], auras-sections)[data-resolved-mode="accordion"]
      [data-part="panel"] {
      overflow-y: clip;
      transition:
        block-size var(--transition-fast, 150ms),
        opacity var(--transition-fast, 150ms);
    }

    :where([data-ui~="sections"], auras-sections)[data-resolved-mode="accordion"]
      [data-part="panel"][hidden] {
      display: block !important;
      block-size: 0;
      opacity: 0;
      overflow-y: clip;
    }

    :where([data-ui~="sections"], auras-sections)[data-resolved-mode="accordion"]
      [data-part="section"][data-expanded] > [data-part="panel"] {
      block-size: auto;
      opacity: 1;
    }
  }

  /* -- Pre-hydration: all content visible -- */

  :where([data-ui~="sections"], auras-sections):not([hydrated])
    [data-part="panel"] {
    display: block;
  }

  /* -- View transitions for tabs panel switching -- */

  :where([data-ui~="sections"], auras-sections)[data-resolved-mode="tabs"]
    [data-part="panel"][data-active] {
    view-transition-name: auras-sections-panel;
  }

  :where([data-ui~="combobox"], auras-combobox) {
    --combobox-gap: var(--space-3);
    --combobox-control-gap: var(--space-2);
    --combobox-control-bg: var(--surface);
    --combobox-control-border-color: var(--border);
    --combobox-control-shadow: var(--shadow-sm);
    --combobox-control-radius: var(--radius-lg);
    --combobox-input-padding-inline: var(--space-3);
    --combobox-input-padding-block: var(--space-2);
    --combobox-toggle-size: 2.75rem;
    --combobox-list-max-block-size: 16rem;
    --combobox-list-bg: var(--surface);
    --combobox-list-border-color: var(--border);
    --combobox-list-shadow: var(--shadow-md);
    --combobox-option-padding-inline: var(--space-3);
    --combobox-option-padding-block: var(--space-2);
    --combobox-option-bg-hover: var(--surface-raised);
    --combobox-option-bg-active: var(--primary-subtle);
    --combobox-option-border-color: transparent;
    --combobox-option-border-color-active: color-mix(
      in oklch,
      var(--primary) 38%,
      var(--border)
    );
    --combobox-panel-bg: var(--surface);
    --combobox-panel-border-color: var(--border);
    --combobox-panel-shadow: var(--shadow-sm);
    --combobox-panel-padding: var(--space-4);

    display: grid;
    gap: var(--combobox-gap);
    min-inline-size: 0;
  }

  :where([data-ui~="combobox"], auras-combobox) > label {
    font-weight: 500;
  }

  :where([data-ui~="combobox"], auras-combobox) [data-part="control"] {
    display: grid;
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    min-inline-size: 0;
    background-color: var(--combobox-control-bg);
    border: 1px solid var(--combobox-control-border-color);
    border-radius: var(--combobox-control-radius);
    box-shadow: var(--combobox-control-shadow);
    overflow: clip;
  }

  :where([data-ui~="combobox"], auras-combobox)
    [data-part="control"]
    > [data-part="input"] {
    inline-size: 100%;
    min-inline-size: 0;
    border: 0;
    border-radius: 0;
    background: transparent;
    box-shadow: none;
    padding-inline: var(--combobox-input-padding-inline);
    padding-block: var(--combobox-input-padding-block);
  }

  :where([data-ui~="combobox"], auras-combobox)
    [data-part="control"]
    > [data-part="input"]:focus {
    outline: none;
  }

  :where([data-ui~="combobox"], auras-combobox)
    [data-part="control"]:focus-within {
    border-color: var(--focus-ring);
    box-shadow: 0 0 0 3px
      color-mix(in oklch, var(--focus-ring) 22%, transparent);
  }

  :where([data-ui~="combobox"], auras-combobox)
    [data-part="control"]
    > [data-part="toggle"] {
    inline-size: var(--combobox-toggle-size);
    block-size: 100%;
    min-block-size: calc(var(--combobox-toggle-size) - 0.25rem);
    padding: 0;
    border: 0;
    border-inline-start: 1px solid var(--combobox-control-border-color);
    border-radius: 0;
    background: transparent;
    color: var(--text-muted);
    box-shadow: none;
  }

  :where([data-ui~="combobox"], auras-combobox)
    [data-part="control"]
    > [data-part="toggle"]::before {
    content: "";
    inline-size: 0.65rem;
    block-size: 0.65rem;
    border-inline-end: 2px solid currentColor;
    border-block-end: 2px solid currentColor;
    transform: rotate(45deg) translateY(-0.15rem);
    transition: transform 160ms ease;
  }

  :where([data-ui~="combobox"], auras-combobox[open])
    [data-part="control"]
    > [data-part="toggle"]::before {
    transform: rotate(225deg) translateY(-0.05rem);
  }

  :where([data-ui~="combobox"], auras-combobox) [data-part="listbox"] {
    display: grid;
    gap: var(--space-1);
    margin: 0;
    padding: var(--space-1);
    list-style: none;
    min-inline-size: 0;
    max-block-size: var(--combobox-list-max-block-size);
    overflow: auto;
    background-color: var(--combobox-list-bg);
    border: 1px solid var(--combobox-list-border-color);
    border-radius: var(--radius-lg);
    box-shadow: var(--combobox-list-shadow);
  }

  :where([data-ui~="combobox"], auras-combobox) [data-part="listbox"][hidden] {
    display: none !important;
  }

  /* Popover-enhanced listbox: top-layer rendering, light dismiss, entry animation */
  :where([data-ui~="combobox"], auras-combobox) [data-part="listbox"][popover] {
    margin: 0;
    inset: unset;
  }
  @media (prefers-reduced-motion: no-preference) {
    :where([data-ui~="combobox"], auras-combobox)
      [data-part="listbox"][popover]:popover-open {
      opacity: 1;
      transform: translateY(0);
      transition:
        opacity var(--transition-fast),
        transform var(--transition-fast),
        overlay var(--transition-fast) allow-discrete,
        display var(--transition-fast) allow-discrete;
    }
    @starting-style {
      :where([data-ui~="combobox"], auras-combobox)
        [data-part="listbox"][popover]:popover-open {
        opacity: 0;
        transform: translateY(-0.25rem);
      }
    }
  }

  /* Anchor positioning: listbox floats relative to control, flips when clipped */
  @supports (anchor-name: --x) {
    :where([data-ui~="combobox"], auras-combobox) [data-part="control"] {
      anchor-name: --combobox-control;
    }
    :where([data-ui~="combobox"], auras-combobox) [data-part="listbox"] {
      position-anchor: --combobox-control;
      inset: unset;
      top: anchor(bottom);
      left: anchor(left);
      min-inline-size: anchor-size(width);
      margin-block-start: var(--space-1);
      position-try-fallbacks: flip-block;
    }
  }

  :where([data-ui~="combobox"], auras-combobox) [data-part="option"] {
    display: grid;
    gap: var(--space-1);
    padding-inline: var(--combobox-option-padding-inline);
    padding-block: var(--combobox-option-padding-block);
    border: 1px solid var(--combobox-option-border-color);
    border-radius: var(--radius-md);
    cursor: pointer;
    user-select: none;
  }

  :where([data-ui~="combobox"], auras-combobox) [data-part="option"]:hover {
    background-color: var(--combobox-option-bg-hover);
  }

  :where([data-ui~="combobox"], auras-combobox)
    [data-part="option"][data-active],
  :where([data-ui~="combobox"], auras-combobox)
    [data-part="option"][data-selected] {
    background-color: var(--combobox-option-bg-active);
    border-color: var(--combobox-option-border-color-active);
  }

  :where([data-ui~="combobox"], auras-combobox) [data-part="empty"] {
    margin: 0;
    color: var(--text-muted);
    font-size: var(--text-sm);
  }

  :where([data-ui~="combobox"], auras-combobox) [data-part="empty"][hidden] {
    display: none !important;
  }

  :where([data-ui~="combobox"], auras-combobox) [data-part="panels"] {
    display: grid;
    gap: var(--space-3);
    min-inline-size: 0;
  }

  :where([data-ui~="combobox"], auras-combobox) [data-part="panel"] {
    display: grid;
    gap: var(--space-3);
    min-inline-size: 0;
    padding: var(--combobox-panel-padding);
    background-color: var(--combobox-panel-bg);
    border: 1px solid var(--combobox-panel-border-color);
    border-radius: var(--radius-lg);
    box-shadow: var(--combobox-panel-shadow);
  }

  :where([data-ui~="combobox"], auras-combobox) [data-part="panel"][hidden] {
    display: none !important;
  }

  :where([data-ui~="splitter"], auras-splitter) {
    --splitter-gap: 0;
    --splitter-handle-size: 0.875rem;
    --splitter-pane-min-block-size: 18rem;
    --splitter-pane-padding: var(--space-4);
    --splitter-pane-bg: var(--surface);
    --splitter-pane-border-color: var(--border);
    --splitter-pane-shadow: var(--shadow-sm);
    --splitter-handle-bg: color-mix(
      in oklch,
      var(--surface-raised) 78%,
      var(--border)
    );
    --splitter-handle-bg-hover: color-mix(
      in oklch,
      var(--primary-subtle) 62%,
      var(--surface-raised)
    );
    --splitter-handle-grip: color-mix(
      in oklch,
      var(--text-muted) 55%,
      transparent
    );

    display: grid;
    gap: var(--splitter-gap);
    min-inline-size: 0;
    align-items: stretch;
  }

  @media (min-width: 48rem) {
    :where([data-ui~="splitter"], auras-splitter) {
      grid-template-columns:
        minmax(0, var(--splitter-primary-size, 50%))
        var(--splitter-handle-size)
        minmax(0, calc(100% - var(--splitter-primary-size, 50%)));
    }
  }

  :where([data-ui~="splitter"], auras-splitter)[data-dragging] {
    user-select: none;
  }

  :where([data-ui~="splitter"], auras-splitter) [data-part="pane"] {
    min-inline-size: 0;
    min-block-size: var(--splitter-pane-min-block-size);
    overflow: auto;
    padding: var(--splitter-pane-padding);
    background-color: var(--splitter-pane-bg);
    border: 1px solid var(--splitter-pane-border-color);
    box-shadow: var(--splitter-pane-shadow);
  }

  /* Narrow viewport (stacked): vertical-style borders and cursor */
  :where([data-ui~="splitter"], auras-splitter)
    [data-part="pane"][data-pane="primary"] {
    border-start-start-radius: var(--radius-lg);
    border-start-end-radius: var(--radius-lg);
    border-end-start-radius: 0;
    border-block-end-width: 0;
  }

  :where([data-ui~="splitter"], auras-splitter)
    [data-part="pane"][data-pane="secondary"] {
    border-end-start-radius: var(--radius-lg);
    border-end-end-radius: var(--radius-lg);
    border-start-end-radius: 0;
    border-block-start-width: 0;
  }

  :where([data-ui~="splitter"], auras-splitter) [data-part="separator"] {
    position: relative;
    padding: 0;
    border: 0;
    border-radius: 0;
    background-color: var(--splitter-handle-bg);
    color: inherit;
    box-shadow: none;
    cursor: row-resize;
  }

  /* Wide viewport: horizontal-style borders and cursor */
  @media (min-width: 48rem) {
    :where([data-ui~="splitter"], auras-splitter)
      [data-part="pane"][data-pane="primary"] {
      border-start-start-radius: var(--radius-lg);
      border-start-end-radius: 0;
      border-end-start-radius: var(--radius-lg);
      border-inline-end-width: 0;
      border-block-end-width: 1px;
    }

    :where([data-ui~="splitter"], auras-splitter)
      [data-part="pane"][data-pane="secondary"] {
      border-start-end-radius: var(--radius-lg);
      border-end-start-radius: 0;
      border-end-end-radius: var(--radius-lg);
      border-inline-start-width: 0;
      border-block-start-width: 1px;
    }

    :where([data-ui~="splitter"], auras-splitter) [data-part="separator"] {
      cursor: col-resize;
    }
  }

  /* Explicit vertical orientation overrides at all viewport widths */
  :where([data-ui~="splitter"], auras-splitter)[orientation="vertical"] {
    grid-template-columns: none;
    grid-template-rows:
      minmax(0, var(--splitter-primary-size, 50%))
      var(--splitter-handle-size)
      minmax(0, calc(100% - var(--splitter-primary-size, 50%)));
  }

  :where([data-ui~="splitter"], auras-splitter)[orientation="vertical"]
    [data-part="pane"][data-pane="primary"] {
    border-start-start-radius: var(--radius-lg);
    border-start-end-radius: var(--radius-lg);
    border-end-start-radius: 0;
    border-inline-end-width: 1px;
    border-block-end-width: 0;
  }

  :where([data-ui~="splitter"], auras-splitter)[orientation="vertical"]
    [data-part="pane"][data-pane="secondary"] {
    border-end-start-radius: var(--radius-lg);
    border-end-end-radius: var(--radius-lg);
    border-start-end-radius: 0;
    border-inline-start-width: 1px;
    border-block-start-width: 0;
  }

  :where([data-ui~="splitter"], auras-splitter)[orientation="vertical"]
    [data-part="separator"] {
    cursor: row-resize;
  }

  :where([data-ui~="splitter"], auras-splitter)
    [data-part="separator"]:where(:hover, :focus-visible) {
    background-color: var(--splitter-handle-bg-hover);
  }

  /* Narrow viewport: horizontal grip (stacked layout) */
  :where([data-ui~="splitter"], auras-splitter) [data-part="separator"]::before {
    content: "";
    position: absolute;
    inset: 50%;
    inline-size: 2.25rem;
    block-size: 0.2rem;
    border-radius: var(--radius-full);
    background: radial-gradient(
      circle at center,
      var(--splitter-handle-grip) 0.08rem,
      transparent 0.09rem
    ) center / 0.55rem 0.2rem repeat-x;
    transform: translate(-50%, -50%);
  }

  /* Wide viewport: vertical grip (side-by-side layout) */
  @media (min-width: 48rem) {
    :where([data-ui~="splitter"], auras-splitter) [data-part="separator"]::before {
      inline-size: 0.2rem;
      block-size: 2.25rem;
      background: radial-gradient(
        circle at center,
        var(--splitter-handle-grip) 0.08rem,
        transparent 0.09rem
      ) center / 0.2rem 0.55rem repeat-y;
    }
  }

  /* Explicit vertical orientation: always horizontal grip */
  :where([data-ui~="splitter"], auras-splitter)[orientation="vertical"]
    [data-part="separator"]::before {
    inline-size: 2.25rem;
    block-size: 0.2rem;
    background: radial-gradient(
      circle at center,
      var(--splitter-handle-grip) 0.08rem,
      transparent 0.09rem
    ) center / 0.55rem 0.2rem repeat-x;
  }

  :where([data-ui~="tree"], auras-tree) {
    --tree-gap: var(--space-4);
    --tree-indent: var(--space-4);
    --tree-rule-color: var(--border);
    --tree-tree-padding: var(--space-2);
    --tree-tree-bg: var(--surface);
    --tree-tree-border-color: var(--border);
    --tree-tree-shadow: var(--shadow-sm);
    --tree-node-padding-inline: var(--space-3);
    --tree-node-padding-block: var(--space-2);
    --tree-node-bg: transparent;
    --tree-node-bg-hover: var(--surface-raised);
    --tree-node-bg-active: var(--primary-subtle);
    --tree-node-border-color: transparent;
    --tree-node-border-color-active: color-mix(
      in oklch,
      var(--primary) 38%,
      var(--border)
    );
    --tree-toggle-size: 1.5rem;
    --tree-panel-bg: var(--surface);
    --tree-panel-border-color: var(--border);
    --tree-panel-shadow: var(--shadow-sm);
    --tree-panel-padding: var(--space-4);

    display: grid;
    gap: var(--tree-gap);
    min-inline-size: 0;
  }

  @media (min-width: 64rem) {
    :where(auras-tree[data-has-panels]) {
      grid-template-columns: minmax(18rem, 22rem) minmax(0, 1fr);
      align-items: start;
    }
  }

  :where([data-ui~="tree"], auras-tree) [data-part="tree"] {
    display: grid;
    gap: var(--space-1);
    align-content: start;
    min-inline-size: 0;
    padding: var(--tree-tree-padding);
    background-color: var(--tree-tree-bg);
    border: 1px solid var(--tree-tree-border-color);
    border-radius: var(--radius-lg);
    box-shadow: var(--tree-tree-shadow);
    list-style: none;
  }

  :where([data-ui~="tree"], auras-tree) [data-part="tree"],
  :where([data-ui~="tree"], auras-tree) [data-part="group"] {
    margin: 0;
    padding-inline-start: 0;
  }

  :where([data-ui~="tree"], auras-tree) [data-part="item"] {
    display: grid;
    gap: var(--space-2);
  }

  :where([data-ui~="tree"], auras-tree) [data-part="item"][data-branch] {
    grid-template-columns: var(--tree-toggle-size) minmax(0, 1fr);
    align-items: start;
  }

  :where([data-ui~="tree"], auras-tree) [data-part="item"] > [data-part="node"] {
    grid-column: 1 / -1;
    inline-size: 100%;
    min-block-size: auto;
    justify-content: flex-start;
    align-items: flex-start;
    flex-direction: column;
    gap: var(--space-1);
    text-align: left;
    background-color: var(--tree-node-bg);
    border: 1px solid var(--tree-node-border-color);
    border-radius: var(--radius-md);
    padding-block: var(--tree-node-padding-block);
    padding-inline: var(--tree-node-padding-inline);
    box-shadow: none;
  }

  :where([data-ui~="tree"], auras-tree)
    [data-part="item"][data-branch]
    > [data-part="node"] {
    grid-column: 2;
  }

  :where([data-ui~="tree"], auras-tree)
    [data-part="item"]
    > [data-part="node"]:hover {
    background-color: var(--tree-node-bg-hover);
  }

  :where([data-ui~="tree"], auras-tree)
    [data-part="item"][data-active]
    > [data-part="node"],
  :where([data-ui~="tree"], auras-tree) [data-part="node"][data-active] {
    background-color: var(--tree-node-bg-active);
    border-color: var(--tree-node-border-color-active);
  }

  :where([data-ui~="tree"], auras-tree)
    [data-part="item"]
    > [data-part="node"]
    > :where(p, small) {
    margin: 0;
    color: var(--text-muted);
    font-size: var(--text-sm);
    line-height: var(--leading-normal);
  }

  :where([data-ui~="tree"], auras-tree)
    [data-part="item"]
    > [data-part="toggle"] {
    grid-column: 1;
    align-self: center;
    justify-self: center;
    inline-size: var(--tree-toggle-size);
    block-size: var(--tree-toggle-size);
    min-block-size: var(--tree-toggle-size);
    padding: 0;
    border: 1px solid transparent;
    border-radius: var(--radius-full);
    background-color: transparent;
    color: var(--text-muted);
    box-shadow: none;
  }

  :where([data-ui~="tree"], auras-tree)
    [data-part="item"][data-branch]
    > [data-part="toggle"]::before {
    content: "";
    inline-size: 0.55rem;
    block-size: 0.55rem;
    border-inline-end: 2px solid currentColor;
    border-block-end: 2px solid currentColor;
    transform: rotate(-45deg);
    transition: transform 160ms ease;
  }

  :where([data-ui~="tree"], auras-tree)
    [data-part="item"][data-expanded]
    > [data-part="toggle"]::before {
    transform: rotate(45deg);
  }

  :where([data-ui~="tree"], auras-tree) [data-part="group"] {
    display: grid;
    gap: var(--space-1);
    min-inline-size: 0;
    margin-inline-start: calc(var(--tree-toggle-size) + var(--space-2));
    padding-inline-start: var(--tree-indent);
    border-inline-start: 1px solid var(--tree-rule-color);
    list-style: none;
  }

  :where([data-ui~="tree"], auras-tree) [data-part="group"][hidden] {
    display: none !important;
  }

  :where([data-ui~="tree"], auras-tree) [data-part="panels"] {
    display: grid;
    gap: var(--space-3);
    min-inline-size: 0;
    align-content: start;
  }

  :where([data-ui~="tree"], auras-tree) [data-part="panel"] {
    display: grid;
    gap: var(--space-3);
    min-inline-size: 0;
    padding: var(--tree-panel-padding);
    background-color: var(--tree-panel-bg);
    border: 1px solid var(--tree-panel-border-color);
    border-radius: var(--radius-lg);
    box-shadow: var(--tree-panel-shadow);
  }

  :where([data-ui~="tree"], auras-tree) [data-part="panel"][hidden] {
    display: none !important;
  }

  /* ===== Example composite ===== */
  :where([data-ui~="example"]) {
    --example-border-color: var(--border);
    --example-radius: var(--radius-lg);
    --example-preview-padding: var(--space-4);
    --example-code-bg: var(--surface-raised);
    --example-code-padding: var(--space-3);
    --example-code-font-size: var(--text-sm);

    border: 1px solid var(--example-border-color);
    border-radius: var(--example-radius);
    contain: content;
    overflow: hidden;
  }

  :where([data-ui~="example"]) > [data-part="header"] {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-2);
    padding: var(--space-2) var(--space-3);
    background-color: var(--example-code-bg);
    border-block-end: 1px solid var(--example-border-color);
    font-size: var(--text-sm);
    font-weight: 600;
  }

  :where([data-ui~="example"]) > [data-part="header"] [data-part="meta"] {
    color: var(--text-muted);
    font-size: var(--text-xs);
    font-weight: 600;
    letter-spacing: 0.06em;
    text-transform: uppercase;
  }

  :where([data-ui~="example"]) > [data-part="preview"] {
    padding: var(--example-preview-padding);
    min-inline-size: 0;
    overflow-x: auto;
  }

  :where([data-ui~="example"]) > [data-part="code"] {
    border-block-start: 1px solid var(--example-border-color);
    padding: var(--example-code-padding);
    background-color: var(--example-code-bg);
    font-size: var(--example-code-font-size);
    overflow-x: auto;
  }

  :where([data-ui~="example"]) > [data-part="code"] pre,
  :where([data-ui~="example"]) > pre[data-part="code"] {
    margin: 0;
    border: 0;
    border-radius: 0;
    background: none;
    padding: 0;
  }

  :where([data-ui~="example"]) > [data-part="code"] code,
  :where([data-ui~="example"]) > pre[data-part="code"] code {
    background: none;
    padding: 0;
    border: 0;
    font-size: inherit;
  }

  :where([data-ui~="diagram"], auras-diagram) {
    --diagram-gap: var(--space-4);
    --diagram-columns: 12;
    --diagram-row-size: 4.5rem;
    --diagram-padding: var(--space-4);
    --diagram-min-inline-size: 42rem;
    --diagram-border-color: var(--border);
    --diagram-canvas-bg: linear-gradient(
      180deg,
      color-mix(in oklch, var(--surface-raised) 65%, var(--surface)),
      var(--surface)
    );
    --diagram-node-bg: var(--surface);
    --diagram-node-border-color: var(--border);
    --diagram-node-shadow: var(--shadow-sm);
    --diagram-connector-color: color-mix(
      in oklch,
      var(--text) 42%,
      var(--primary)
    );
    --diagram-connector-stroke: 2.5;
    --diagram-connector-min-block-size: calc(var(--diagram-row-size) * 0.8);
    --diagram-node-bg-active: var(--primary-subtle);
    --diagram-node-border-color-active: color-mix(
      in oklch,
      var(--primary) 38%,
      var(--border)
    );
    --diagram-panel-bg: var(--surface);
    --diagram-panel-border-color: var(--border);
    --diagram-panel-shadow: var(--shadow-sm);
    --diagram-panel-padding: var(--space-4);

    display: grid;
    grid-template-columns: minmax(0, 1fr);
    gap: var(--space-3);
    min-inline-size: 0;
    contain: inline-size;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
  }

  @media (max-width: 40rem) {
    :where([data-ui~="diagram"], auras-diagram) {
      --diagram-min-inline-size: 28rem;
      --diagram-row-size: 3.5rem;
      --diagram-padding: var(--space-2);
      --diagram-gap: var(--space-2);
    }
  }

  @media (min-width: 64rem) {
    :where(auras-diagram) {
      grid-template-columns: minmax(0, 1.65fr) minmax(18rem, 1fr);
      align-items: start;
    }

    :where(auras-diagram) > [data-part="caption"] {
      grid-column: 1 / -1;
    }
  }

  :where([data-ui~="diagram"], auras-diagram)
    > :where(figcaption, [data-part="caption"]) {
    color: var(--text-muted);
    font-size: var(--text-sm);
    line-height: var(--leading-normal);
  }

  :where([data-ui~="diagram"], auras-diagram) [data-part="canvas"] {
    display: grid;
    grid-template-columns: repeat(var(--diagram-columns), minmax(0, 1fr));
    grid-auto-rows: minmax(var(--diagram-row-size), auto);
    gap: var(--diagram-gap);
    align-items: stretch;
    min-inline-size: var(--diagram-min-inline-size);
    padding: var(--diagram-padding);
    background: var(--diagram-canvas-bg);
    border: 1px solid var(--diagram-border-color);
    border-radius: var(--radius-lg);
  }

  :where(auras-diagram) [data-part="panels"] {
    display: grid;
    gap: var(--space-3);
    min-inline-size: 0;
    align-content: start;
  }

  :where(auras-diagram) [data-part="panel"] {
    display: grid;
    gap: var(--space-3);
    min-inline-size: 0;
    padding: var(--diagram-panel-padding);
    background-color: var(--diagram-panel-bg);
    border: 1px solid var(--diagram-panel-border-color);
    border-radius: var(--radius-lg);
    box-shadow: var(--diagram-panel-shadow);
  }

  :where(auras-diagram) [data-part="panel"][hidden] {
    display: none !important;
  }

  :where([data-ui~="diagram"], auras-diagram) [data-part="node"],
  :where([data-ui~="diagram"], auras-diagram) [data-part="connector"] {
    grid-column: var(--diagram-column, auto);
    grid-row: var(--diagram-row, auto);
    min-inline-size: 0;
  }

  :where([data-ui~="diagram"], auras-diagram) [data-part="node"] {
    --diagram-node-accent: var(--primary);

    display: grid;
    align-content: start;
    gap: var(--space-1);
    padding: var(--space-3);
    background-color: var(--diagram-node-bg);
    border: 1px solid var(--diagram-node-border-color);
    border-inline-start: 0.35rem solid var(--diagram-node-accent);
    border-radius: var(--radius-lg);
    box-shadow: var(--diagram-node-shadow);
  }

  :where(auras-diagram)
    :where(button, a, [role="button"], [tabindex])[data-part="node"] {
    inline-size: 100%;
    min-block-size: auto;
    text-align: left;
    justify-content: flex-start;
    align-items: flex-start;
    box-shadow: var(--diagram-node-shadow);
  }

  :where(auras-diagram) [data-part="node"][data-active] {
    background-color: var(--diagram-node-bg-active);
    border-color: var(--diagram-node-border-color-active);
  }

  :where([data-ui~="diagram"], auras-diagram)
    [data-part="node"]
    > :where(h3, strong) {
    margin: 0;
    font-size: var(--text-base);
    line-height: var(--leading-tight);
  }

  :where([data-ui~="diagram"], auras-diagram)
    [data-part="node"]
    > :where(p, small) {
    margin: 0;
    color: var(--text-muted);
    font-size: var(--text-sm);
    line-height: var(--leading-normal);
  }

  :where([data-ui~="diagram"], auras-diagram)
    [data-part="node"][data-kind="input"] {
    --diagram-node-accent: var(--color-info);
  }

  :where([data-ui~="diagram"], auras-diagram)
    [data-part="node"][data-kind="process"] {
    --diagram-node-accent: var(--primary);
  }

  :where([data-ui~="diagram"], auras-diagram)
    [data-part="node"][data-kind="decision"] {
    --diagram-node-accent: var(--color-warning);
  }

  :where([data-ui~="diagram"], auras-diagram)
    [data-part="node"][data-kind="output"] {
    --diagram-node-accent: var(--color-success);
  }

  :where([data-ui~="diagram"], auras-diagram) [data-part="connector"] {
    display: grid;
    place-items: center;
    color: var(--diagram-connector-color);
    min-block-size: var(--diagram-connector-min-block-size);
    pointer-events: none;
  }

  :where([data-ui~="diagram"], auras-diagram) [data-part="connector"] svg {
    inline-size: 100%;
    block-size: 100%;
    overflow: visible;
  }

  :where([data-ui~="diagram"], auras-diagram)
    [data-part="connector"]
    :where(path, polyline, line) {
    fill: none;
    stroke: currentColor;
    stroke-width: var(--diagram-connector-stroke);
    stroke-linecap: round;
    stroke-linejoin: round;
  }

  :where([data-ui~="diagram"], auras-diagram)
    [data-part="connector"]
    [data-marker="arrow"] {
    fill: currentColor;
    stroke: none;
  }

  /* ---------- Example (documentation demo block) ---------- */
  :where([data-ui~="example"]) {
    --example-border-color: var(--border);
    --example-radius: var(--radius-lg);
    --example-preview-padding: var(--space-4);
    --example-code-bg: var(--surface-raised);
    --example-code-padding: var(--space-3);
    --example-code-font-size: var(--text-sm);

    border: 1px solid var(--example-border-color);
    border-radius: var(--example-radius);
    overflow: hidden;
  }

  :where([data-ui~="example"]) > [data-part="header"] {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-2);
    padding: var(--space-2) var(--example-preview-padding);
    border-block-end: 1px solid var(--example-border-color);
    background-color: var(--example-code-bg);
    font-size: var(--text-sm);
  }

  :where([data-ui~="example"]) > [data-part="header"] [data-part="meta"] {
    font-size: var(--text-xs);
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
  }

  :where([data-ui~="example"]) > [data-part="preview"] {
    padding: var(--example-preview-padding);
    min-inline-size: 0;
    overflow-x: auto;
  }

  :where([data-ui~="example"]) > [data-part="code"] {
    border-block-start: 1px solid var(--example-border-color);
    padding: var(--example-code-padding);
    background-color: var(--example-code-bg);
    font-size: var(--example-code-font-size);
    overflow-x: auto;
  }

  :where([data-ui~="example"]) > [data-part="code"] pre {
    margin: 0;
  }

  :where([data-ui~="example"]) > [data-part="code"] code {
    background: none;
    padding: 0;
    border: 0;
    font-size: inherit;
  }

  /* View transitions for panel switching (tabs, master-detail) */
  :where(
    [data-ui~="tabs"],
    auras-tabs,
    [data-ui~="master-detail"],
    auras-master-detail
  ) [data-part="panel"][data-active] {
    view-transition-name: auras-panel;
  }

  ::view-transition-old(auras-panel) {
    animation: var(--transition-fast, 150ms) ease-out both auras-vt-fade-out;
  }

  ::view-transition-new(auras-panel) {
    animation: var(--transition-fast, 150ms) ease-out both auras-vt-fade-in;
  }

  @keyframes auras-vt-fade-out {
    to {
      opacity: 0;
    }
  }

  ::view-transition-old(auras-sections-panel) {
    animation: var(--transition-fast, 150ms) ease-out both auras-vt-fade-out;
  }

  ::view-transition-new(auras-sections-panel) {
    animation: var(--transition-fast, 150ms) ease-out both auras-vt-fade-in;
  }

  @keyframes auras-vt-fade-in {
    from {
      opacity: 0;
    }
  }
}