web: focus modal, slice 8 of M3

Clicking a panel's network (cursor zoom-in, a real button for keyboard
users) or its menu's Focus item opens the modal: the same SVG at the
same global round rendered up to 90vw/85vh over the spec scrim, with a
second PlayerBar docked in the footer sharing the store. Only the page
PlayerBar owns the global keyboard map, so keys are never handled
twice.

role=dialog with aria-modal, labelled by the panel name, focus moves in
and is trapped, Esc/X/scrim close, and focus returns to the opener.
focusPanelId already lives in the URL, so shared links open
pre-focused; on mobile the modal becomes a full-screen sheet.

web/src/App.vue

@@ -3,6 +3,7 @@ import { onMounted } from 'vue'
 import AppBar from '@/components/AppBar.vue'
 import ControlsCard from '@/components/ControlsCard.vue'
 import ErrorBanner from '@/components/ErrorBanner.vue'
+import FocusModal from '@/components/FocusModal.vue'
 import FooterDisclaimer from '@/components/FooterDisclaimer.vue'
 import HeroHeadline from '@/components/HeroHeadline.vue'
 import LegendRow from '@/components/LegendRow.vue'
@@ -45,6 +46,7 @@ onMounted(async () => {
     />
   </main>
   <FooterDisclaimer />
+  <FocusModal v-if="store.state.focusPanelId" />
   <div class="visually-hidden" aria-live="polite">{{ store.state.announcement }}</div>
 </template>
 

web/src/components/FocusModal.vue

@@ -0,0 +1,226 @@
+<script setup lang="ts">
+import { computed, onBeforeUnmount, onMounted, ref } from 'vue'
+import NetworkView from './NetworkView.vue'
+import PlayerBar from './PlayerBar.vue'
+import { useSimStore } from '@/composables/useSimStore'
+import { accentForPanel } from '@/lib/accents'
+import { roundPct } from '@/lib/format'
+import { reachedCountAtRound } from '@/lib/reach'
+
+// One panel rendered large (spec 5.8): same SVG, same global round, with
+// a PlayerBar docked at the modal footer (both bars share the store, so
+// they stay in sync). focusPanelId is URL state, so a shared link opens
+// pre-focused. Focus is trapped; Esc, the X, and the scrim close it.
+
+const store = useSimStore()
+
+const panelIndex = computed(() =>
+  store.state.panels.findIndex((panel) => panel.id === store.state.focusPanelId),
+)
+const panel = computed(() =>
+  panelIndex.value >= 0 ? store.state.panels[panelIndex.value] : undefined,
+)
+const result = computed(() =>
+  panel.value ? store.state.resultsByPanelId[panel.value.id] : undefined,
+)
+const numStudents = computed(() =>
+  panel.value ? store.effectiveConfig(panel.value).numStudents : 0,
+)
+const reachedCount = computed(() =>
+  result.value ? reachedCountAtRound(result.value.reachedAtRound, store.state.round) : 0,
+)
+const reachedPctNow = computed(() => (reachedCount.value / Math.max(numStudents.value, 1)) * 100)
+const tone = computed(() =>
+  roundPct(reachedPctNow.value) <= store.preset.toneThresholdPct ? 'good' : 'bad',
+)
+
+const modal = ref<HTMLElement | null>(null)
+let openerElement: HTMLElement | null = null
+
+function close() {
+  store.setFocusPanel(null)
+}
+
+function focusableElements(): HTMLElement[] {
+  const selector =
+    'button:not(:disabled), [href], input:not(:disabled), select, [tabindex]:not([tabindex="-1"])'
+  return Array.from(modal.value?.querySelectorAll<HTMLElement>(selector) ?? [])
+}
+
+function onKeydown(event: KeyboardEvent) {
+  if (event.key === 'Escape') {
+    close()
+    return
+  }
+  if (event.key !== 'Tab') return
+  const elements = focusableElements()
+  const first = elements[0]
+  const last = elements[elements.length - 1]
+  if (!first || !last) return
+  if (event.shiftKey && document.activeElement === first) {
+    event.preventDefault()
+    last.focus()
+  } else if (!event.shiftKey && document.activeElement === last) {
+    event.preventDefault()
+    first.focus()
+  }
+}
+
+onMounted(() => {
+  openerElement = document.activeElement instanceof HTMLElement ? document.activeElement : null
+  focusableElements()[0]?.focus()
+  document.addEventListener('keydown', onKeydown)
+  document.body.style.overflow = 'hidden'
+})
+
+onBeforeUnmount(() => {
+  document.removeEventListener('keydown', onKeydown)
+  document.body.style.overflow = ''
+  openerElement?.focus()
+})
+</script>
+
+<template>
+  <Teleport to="body">
+    <div v-if="panel" class="scrim" @click.self="close">
+      <div ref="modal" class="modal" role="dialog" aria-modal="true" :aria-label="panel.label">
+        <div class="head">
+          <span
+            class="swatch"
+            :style="{ background: accentForPanel(panelIndex) }"
+            aria-hidden="true"
+          />
+          <span class="label">{{ panel.label }}</span>
+          <span v-if="result" class="stat" :class="tone">
+            {{ roundPct(reachedPctNow) }}%
+            <span class="stat-detail">{{ reachedCount }} of {{ numStudents }} reached</span>
+          </span>
+          <button class="close" type="button" aria-label="Close" @click="close">
+            <svg class="ic" viewBox="0 0 24 24"><path d="M6 6l12 12M18 6L6 18" /></svg>
+          </button>
+        </div>
+        <NetworkView :panel="panel" class="big-net" />
+        <div class="dock">
+          <PlayerBar :global-keys="false" />
+        </div>
+      </div>
+    </div>
+  </Teleport>
+</template>
+
+<style scoped>
+.scrim {
+  position: fixed;
+  inset: 0;
+  z-index: 40;
+  background: rgba(15, 23, 42, 0.5);
+  display: grid;
+  place-items: center;
+  padding: 24px;
+}
+
+.modal {
+  width: min(1100px, 90vw);
+  max-height: 85vh;
+  display: flex;
+  flex-direction: column;
+  background: var(--surface);
+  border: 1px solid var(--border);
+  border-radius: var(--radius);
+  box-shadow: var(--shadow-lift);
+  padding: 18px 22px 14px;
+  overflow: auto;
+}
+
+.head {
+  display: flex;
+  align-items: center;
+  gap: 10px;
+}
+
+.swatch {
+  width: 10px;
+  height: 10px;
+  border-radius: 3px;
+  flex: none;
+}
+
+.label {
+  font-size: 15px;
+  font-weight: 650;
+  color: var(--ink);
+  flex: 1;
+  min-width: 0;
+  white-space: nowrap;
+  overflow: hidden;
+  text-overflow: ellipsis;
+}
+
+.stat {
+  font-size: 17px;
+  font-weight: 700;
+}
+
+.stat.bad {
+  color: var(--spread);
+}
+
+.stat.good {
+  color: var(--edu);
+}
+
+.stat-detail {
+  font-size: 12.5px;
+  font-weight: 500;
+  color: var(--ink-4);
+  margin-left: 6px;
+}
+
+.close {
+  width: 32px;
+  height: 32px;
+  border: none;
+  background: none;
+  border-radius: 10px;
+  color: var(--ink-3);
+  display: grid;
+  place-items: center;
+  cursor: pointer;
+  flex: none;
+}
+
+.close:hover {
+  background: var(--bg);
+  color: var(--ink);
+}
+
+.big-net {
+  flex: 1;
+  min-height: 0;
+}
+
+.dock {
+  margin-top: 4px;
+}
+
+.dock :deep(.playerwrap) {
+  margin-top: 8px;
+}
+
+@media (max-width: 760px) {
+  .scrim {
+    padding: 0;
+  }
+
+  .modal {
+    width: 100vw;
+    height: 100dvh;
+    max-height: none;
+    border-radius: 0;
+    border: none;
+  }
+
+  /* Inside the full-screen sheet the docked player keeps its fixed
+     bottom position from the mobile player styles; that is the design. */
+}
+</style>

web/src/components/PlayerBar.vue

@@ -9,6 +9,10 @@ import { useSimStore } from '@/composables/useSimStore'
 // and Home/End work globally except in text inputs; on the scrubber the
 // browser handles them natively.
 
+// The modal docks a second PlayerBar over the same store; only the page
+// instance owns the global keyboard map so keys are not handled twice.
+const props = withDefaults(defineProps<{ globalKeys?: boolean }>(), { globalKeys: true })
+
 const store = useSimStore()
 const playback = usePlayback()
 
@@ -62,8 +66,12 @@ function onGlobalKeydown(event: KeyboardEvent) {
   }
 }
 
-onMounted(() => document.addEventListener('keydown', onGlobalKeydown))
-onBeforeUnmount(() => document.removeEventListener('keydown', onGlobalKeydown))
+onMounted(() => {
+  if (props.globalKeys) document.addEventListener('keydown', onGlobalKeydown)
+})
+onBeforeUnmount(() => {
+  if (props.globalKeys) document.removeEventListener('keydown', onGlobalKeydown)
+})
 </script>
 
 <template>

web/src/components/ScenarioPanel.vue

@@ -22,6 +22,7 @@ const failed = computed(() => store.state.failedPanelIds.has(props.panel.id))
 const menuItems = computed<PanelMenuItem[]>(() => [
   { key: 'edit', label: 'Edit' },
   { key: 'rename', label: 'Rename' },
+  { key: 'focus', label: 'Focus' },
   { key: 'duplicate', label: 'Duplicate', disabled: store.state.panels.length >= MAX_PANELS },
   { key: 'remove', label: 'Remove', disabled: store.state.panels.length <= 1 },
 ])
@@ -34,6 +35,9 @@ function onMenuSelect(itemKey: string) {
       focusLabelOnOpen.value = itemKey === 'rename'
       store.state.editingPanelId = props.panel.id
       break
+    case 'focus':
+      store.setFocusPanel(props.panel.id)
+      break
     case 'duplicate':
       store.duplicatePanel(props.panel.id)
       kebabButton.value?.focus()
@@ -136,7 +140,14 @@ const dimmed = computed(() => store.state.runState === 'running' && result.value
       <div class="chips">
         <span v-for="chip in chips" :key="chip.key" class="chip">{{ chip.text }}</span>
       </div>
-      <NetworkView :panel="panel" />
+      <button
+        class="netbtn"
+        type="button"
+        :aria-label="`Enlarge ${panel.label}`"
+        @click="store.setFocusPanel(panel.id)"
+      >
+        <NetworkView :panel="panel" />
+      </button>
     </template>
     <template v-else>
       <div class="skeleton" aria-hidden="true">
@@ -273,6 +284,16 @@ const dimmed = computed(() => store.state.runState === 'running' && result.value
   flex-wrap: wrap;
 }
 
+.netbtn {
+  display: block;
+  width: 100%;
+  border: none;
+  background: none;
+  padding: 0;
+  cursor: zoom-in;
+  border-radius: 8px;
+}
+
 .chip {
   font-size: 11.5px;
   font-weight: 550;