/* Breakpoints: condensed top bar on tablets and narrow desktops, and the phone layout
   (≤ 900px) with a bottom tab bar and a slim route bar above it. */
@media (min-width: 901px) {
  .phone-only {
    display: none !important;
  }
  .bottom-nav {
    display: none;
  }
}

@media (max-width: 1279px) {
  .story-switcher-meta {
    display: none;
  }
  .topbar {
    gap: var(--space-6);
  }
  .segmented.mode-tabs > button {
    padding: 0 var(--space-6);
  }
}

@media (max-width: 1100px) and (min-width: 901px) {
  .topbar {
    gap: var(--space-4);
    padding: 0 var(--space-6) 0 var(--space-7);
  }
  .brand-name,
  .topbar-divider,
  .export-suffix {
    display: none;
  }
  .story-switcher-anchor {
    max-width: 180px;
  }
  .segmented.mode-tabs > button {
    padding: 0 var(--space-5);
  }
  .diagnostics-text {
    display: none;
  }
  .diagnostics-count {
    display: inline;
    font-family: var(--font-mono);
  }
  .story-pane-body {
    grid-template-columns: 180px minmax(0, 1fr);
    gap: var(--space-9);
  }
}

@media (max-width: 900px) {
  .desktop-only {
    display: none !important;
  }
  #app {
    min-height: 0;
  }

  /* Top bar: logo, story title switcher, undo, diagnostics icon, more menu. */
  .topbar {
    gap: var(--space-1);
    padding: 0 var(--space-2) 0 var(--space-7);
  }
  .brand-mark {
    width: 26px;
    height: 26px;
  }
  .brand-name,
  .topbar-divider,
  .mode-tabs {
    display: none;
  }
  .brand {
    margin-right: var(--space-4);
  }
  .story-switcher-anchor {
    flex: 0 1 auto;
    min-width: 0;
  }
  .story-switcher {
    height: var(--touch-target);
    padding: 0 var(--space-2);
    border: 0;
    gap: var(--space-3);
  }
  .story-switcher-title {
    font-size: var(--font-size-xl);
  }
  .icon-button,
  .history .icon-button {
    width: var(--touch-target);
    height: var(--touch-target);
  }
  .diagnostics-button {
    position: relative;
    justify-content: center;
    width: var(--touch-target);
    height: var(--touch-target);
    padding: 0;
    border: 0;
  }
  .diagnostics-button .icon {
    width: 20px;
    height: 20px;
  }
  .diagnostics-text {
    display: none;
  }
  .diagnostics-count {
    position: absolute;
    top: 4px;
    right: 2px;
    display: grid;
    place-items: center;
    min-width: 18px;
    height: 18px;
    padding: 0 4px;
    border-radius: var(--radius-pill);
    background: var(--color-accent);
    color: var(--color-on-accent);
    font: 700 var(--font-size-2xs)/1 var(--font-mono);
  }
  .story-menu {
    position: fixed;
    top: calc(var(--topbar-height) - 4px);
    left: var(--space-6);
    right: var(--space-6);
    width: auto;
    max-width: none;
  }
  .menu-item {
    min-height: var(--touch-target);
  }

  /* Workspace: one panel at a time, chosen by the bottom tab. */
  .workspace {
    display: flex;
    flex-direction: column;
  }
  .workspace > .panel,
  .workspace > .panel-resize {
    display: none;
  }
  .workspace[data-mode="node"][data-mobile="library"] > .library,
  .workspace[data-mode="node"][data-mobile="inspector"] > .inspector,
  .workspace:not([data-mode="node"]) > .inspector {
    display: flex;
    flex: 1;
    border: 0;
  }
  .workspace[data-mode="node"][data-mobile="graph"] > .stage {
    display: block;
    flex: 1;
  }
  .workspace > .route-dock {
    order: 10;
  }

  /* Node index */
  .library-head {
    padding: var(--space-6) var(--space-7) var(--space-4);
    gap: var(--space-5);
  }
  .library-title {
    display: none;
  }
  .search-field {
    height: var(--touch-target);
    border-radius: var(--radius-lg);
  }
  .chip {
    height: 32px;
  }
  .library-content {
    padding: 0 var(--space-4);
  }
  .node-row {
    min-height: var(--touch-target);
    padding: var(--space-6) var(--space-5);
    gap: var(--space-6);
    border-radius: 0;
    border-bottom: 1px solid var(--color-divider);
  }
  .kind-marker {
    margin-top: 7px;
  }
  .node-row-text {
    font-size: var(--font-size-base);
  }
  .library-foot {
    padding: var(--space-4) var(--space-7);
  }
  .dashed-button,
  .primary-button,
  .secondary-button {
    min-height: var(--touch-target);
  }

  /* Graph on phones */
  .graph-toolbar {
    top: var(--space-4);
    left: var(--space-4);
    right: var(--space-4);
  }
  .zoom-group .icon-button.tool {
    width: 40px;
    height: 40px;
  }
  .segmented.floating > button {
    height: 40px;
  }

  /* Route dock: slim ink bar above the bottom nav; expands into a sheet. */
  .route-dock {
    flex: none;
    align-self: stretch;
    margin: 0 var(--space-6) var(--space-4);
    background: var(--color-inverse-surface);
    color: var(--color-inverse-text);
    box-shadow: none;
  }
  .route-dock-bar {
    min-height: var(--touch-target);
    gap: var(--space-6);
    padding: 0 var(--space-1) 0 14px;
  }
  .route-dock-summary {
    gap: var(--space-6);
  }
  .route-terms {
    gap: var(--space-6);
    color: var(--color-inverse-muted);
  }
  .route-term b {
    color: var(--color-inverse-text);
  }
  .route-term--total b {
    color: var(--color-inverse-accent);
  }
  .route-term--remaining,
  .route-range,
  .route-dock-toggle span {
    display: none;
  }
  .route-dock-unavailable {
    color: var(--color-inverse-accent);
  }
  .route-dock-toggle {
    width: var(--touch-target);
    height: var(--touch-target);
    justify-content: center;
    padding: 0;
  }
  .route-dock-bar:hover {
    background: color-mix(in srgb, var(--color-inverse-text) 8%, var(--color-inverse-surface));
  }
  .route-dock.is-expanded {
    position: fixed;
    z-index: var(--z-drawer);
    left: 0;
    right: 0;
    bottom: calc(var(--bottom-nav-height) + env(safe-area-inset-bottom, 0px));
    margin: 0;
    border-radius: var(--radius-lg) var(--radius-lg) 0 0;
    background: var(--color-surface);
    color: var(--color-text);
    box-shadow: var(--shadow-menu);
  }
  .route-dock.is-expanded .route-dock-bar {
    margin: 0 var(--space-4) var(--space-4);
    border: 0;
    border-radius: var(--radius-lg);
    background: var(--color-inverse-surface);
    color: var(--color-inverse-text);
  }
  .route-dock-resize {
    height: 22px;
  }
  .route-dock-resize::after {
    margin-top: 9px;
  }
  .route-dock-tabs button {
    min-height: var(--touch-target);
  }
  .route-calc-grid {
    gap: var(--space-2);
  }
  .route-calc-term {
    padding: var(--space-3);
  }
  .route-page-actions button,
  .route-detail-list button,
  .route-list button {
    min-height: var(--touch-target);
  }

  /* Node inspector on phones: prev/next in the header, attributes collapsed. */
  .node-head {
    gap: var(--space-1);
    min-height: 56px;
    padding: var(--space-2) var(--space-2);
  }
  .node-head-title {
    justify-content: center;
    gap: var(--space-4);
  }
  .node-id {
    font-size: var(--font-size-md);
  }
  .node-body {
    gap: var(--space-8);
    padding: var(--space-7) var(--space-7) var(--space-9);
  }
  .field textarea.reading {
    min-height: 0;
    font-size: var(--font-size-lg);
    border-radius: var(--radius-lg);
  }
  .attr-details {
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
  }
  .attr-details > summary {
    display: flex;
    align-items: center;
    gap: var(--space-4);
    min-height: 48px;
    padding: 0 14px;
    cursor: pointer;
    list-style: none;
    font-weight: 700;
  }
  .attr-details > summary::-webkit-details-marker {
    display: none;
  }
  .attr-summary {
    flex: 1;
    min-width: 0;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    text-align: right;
    color: var(--color-text-muted);
    font-size: var(--font-size-xs);
    font-weight: 400;
  }
  .attr-details > summary .icon {
    width: 16px;
    height: 16px;
    color: var(--color-text-muted);
    transition: transform 0.15s;
  }
  .attr-details[open] > summary .icon {
    transform: rotate(180deg);
  }
  .attr-details[open] > .attr-grid {
    padding: var(--space-2) 14px 14px;
  }
  .option-card {
    border-radius: var(--radius-lg);
  }
  .card-actions .icon-button.tool,
  .card-head .icon-button.tool {
    width: var(--touch-target);
    height: var(--touch-target);
  }
  .option-target {
    min-height: var(--touch-target);
  }
  .next-step-head {
    flex-wrap: wrap;
  }

  /* Story pane on phones: mode segmented on top, sections as a scrollable row. */
  .story-pane-body {
    display: block;
    padding: 0 var(--space-7) 48px;
  }
  .pane-modes {
    display: flex;
    margin: var(--space-6) var(--space-7) 0;
  }
  .pane-modes > button {
    flex: 1;
    height: 40px;
    padding: 0 var(--space-4);
  }
  .section-nav {
    position: static;
    margin: var(--space-6) calc(var(--space-7) * -1) 0;
    overflow-x: auto;
  }
  .section-nav ul {
    flex-direction: row;
    gap: var(--space-3);
    padding: 0 var(--space-7) var(--space-2);
  }
  .section-nav button {
    min-height: var(--touch-target);
    gap: var(--space-4);
    white-space: nowrap;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-pill);
  }
  .section-nav button[aria-current="page"] {
    border-color: var(--color-selected);
    background: var(--color-selected);
    color: var(--color-on-selected);
  }
  .section-nav button[aria-current="page"] .section-count {
    color: var(--color-on-selected);
  }
  .story-pane-content {
    padding-top: var(--space-8);
  }
  .pane-head h2 {
    font-size: var(--font-size-2xl);
  }
  /* Preview on phones: compact stats on top, the text scrolls, actions in a bottom sheet. */
  .story-pane--preview .story-pane-content {
    padding-top: 0;
  }
  .preview-layout {
    display: flex;
    flex-direction: column;
    padding: 0;
  }
  .preview-side {
    display: contents;
  }
  .preview-nav {
    order: 1;
    flex: none;
    flex-wrap: nowrap;
    overflow-x: auto;
    padding: var(--space-5) var(--space-7) 0;
  }
  .preview-nav .small-button {
    min-height: 36px;
  }
  .preview-stats {
    order: 2;
    flex: none;
    gap: var(--space-2);
    padding: var(--space-4) var(--space-7) var(--space-2);
    border: 0;
  }
  .preview-metrics .metric {
    display: flex;
    align-items: baseline;
    gap: var(--space-3);
    padding: var(--space-2) var(--space-5);
  }
  .preview-metrics .metric strong {
    font-size: var(--font-size-md);
  }
  .preview-clues,
  .preview-path {
    overflow: hidden;
    white-space: nowrap;
    text-overflow: ellipsis;
  }
  .preview-reading {
    order: 3;
    flex: 1;
    padding: var(--space-4) var(--space-7) var(--space-7);
    border-top: 1px solid var(--color-divider);
  }
  .preview-text {
    font-size: var(--font-size-lg);
  }
  .preview-actions {
    order: 4;
    flex: none;
    max-height: 45dvh;
    overflow: auto;
    border-top: 1px solid var(--color-border);
    background: var(--color-surface);
    box-shadow: 0 -4px 12px var(--color-shadow);
  }
  .preview-actions > summary {
    position: sticky;
    top: 0;
    z-index: 1;
    display: flex;
    align-items: center;
    gap: var(--space-4);
    min-height: var(--touch-target);
    padding: 0 var(--space-7);
    background: var(--color-surface);
    font-weight: 700;
    cursor: pointer;
    list-style: none;
  }
  .preview-actions > summary::-webkit-details-marker {
    display: none;
  }
  .preview-actions-count {
    color: var(--color-text-muted);
    font: var(--font-size-xs) var(--font-mono);
  }
  .preview-actions > summary .icon {
    width: 16px;
    height: 16px;
    margin-left: auto;
    color: var(--color-text-muted);
    transform: rotate(180deg);
  }
  .preview-actions[open] > summary .icon {
    transform: none;
  }
  .preview-actions-body {
    padding: 0 var(--space-7) var(--space-6);
  }

  /* Bottom tab bar */
  .bottom-nav {
    flex: none;
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    height: calc(var(--bottom-nav-height) + env(safe-area-inset-bottom, 0px));
    padding-bottom: calc(var(--space-4) + env(safe-area-inset-bottom, 0px));
    border-top: 1px solid var(--color-border);
    background: var(--color-surface);
  }
  .bottom-nav button {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: var(--space-1);
    min-height: var(--touch-target);
    color: var(--color-text-muted);
    font-size: var(--font-size-2xs);
  }
  .bottom-nav button .icon {
    width: 22px;
    height: 22px;
  }
  .bottom-nav button[aria-current="page"] {
    color: var(--color-accent-text);
    font-weight: 700;
  }
  .bottom-nav button:focus-visible {
    outline-offset: -4px;
  }

  .diagnostics-drawer {
    top: calc(var(--topbar-height) + var(--space-2));
    left: var(--space-2);
    right: var(--space-2);
    width: auto;
    max-height: calc(100dvh - var(--topbar-height) - var(--bottom-nav-height) - 16px);
  }
  .toast {
    bottom: calc(var(--bottom-nav-height) + 64px);
  }
  .graph-overlay {
    inset: 56px var(--space-2) var(--space-2);
    padding: var(--space-6);
  }
}

@media (max-width: 420px) {
  .attr-grid,
  .option-card .field-inline {
    grid-template-columns: minmax(0, 1fr);
  }
  .empty-state-actions {
    flex-direction: column;
    width: 100%;
  }
}