feat: add Calendar blueprint illustration

Transcribe the calendar blueprint from blueprint-ontology (README +
calendar.als): Navigate, Render, Load, Scope functions, its own
Idle/Loading/Refreshing/Error lifecycle, and a bespoke month/week
specimen. Composition follows the formal model (Async + Pullable).

src/data/blueprints.ts

@@ -6,8 +6,10 @@ import type { Component } from "vue"
 import type { Blueprint } from "./blueprint"
 import { list } from "./listBlueprint"
 import { grid } from "./gridBlueprint"
+import { calendar } from "./calendarBlueprint"
 import ListSpecimen from "@/specimens/ListSpecimen.vue"
 import GridSpecimen from "@/specimens/GridSpecimen.vue"
+import CalendarSpecimen from "@/specimens/CalendarSpecimen.vue"
 
 export interface RegistryEntry {
   blueprint: Blueprint
@@ -17,6 +19,7 @@ export interface RegistryEntry {
 export const REGISTRY: Record<string, RegistryEntry> = {
   list: { blueprint: list, specimen: ListSpecimen },
   grid: { blueprint: grid, specimen: GridSpecimen },
+  calendar: { blueprint: calendar, specimen: CalendarSpecimen },
 }
 
 export const BLUEPRINTS: Blueprint[] = Object.values(REGISTRY).map((e) => e.blueprint)

src/data/calendarBlueprint.ts

@@ -0,0 +1,208 @@
+// The Calendar blueprint, as data. Lifted from the blueprint-ontology `calendar`
+// README + calendar.als. Calendar has its OWN lifecycle (no LoadingMore; adds
+// navigate/changeScope transitions), so it defines its own state machine rather
+// than sharing LOADSTATE_MACHINE with List/Grid. `visible` is a viewport
+// projection Calendar owns — not Filterable — so only Async + Pullable are
+// represented as composed capabilities, matching what the formal model models.
+
+import type { Blueprint, StateMachine } from "./blueprint"
+
+// Idle ⇄ Loading (navigate/changeScope out, succeed in), plus refresh via
+// Refreshing and the two failure edges. Node coordinates are hand-placed.
+const CALENDAR_MACHINE: StateMachine = {
+  nodes: [
+    { id: "loading", x: 70, y: 150, w: 110, h: 40, label: "Loading" },
+    { id: "idle", x: 300, y: 150, w: 96, h: 40, label: "Idle" },
+    { id: "refreshing", x: 540, y: 56, w: 130, h: 40, label: "Refreshing" },
+    { id: "error", x: 770, y: 150, w: 96, h: 40, label: "Error" },
+  ],
+  edges: [
+    { from: "loading", to: "idle", label: "succeed()", kind: "succeed", off: 24 },
+    { from: "loading", to: "error", label: "fail()", kind: "fail", off: 150 },
+    { from: "idle", to: "loading", label: "navigate(δ)", kind: "navigate", off: 20 },
+    { from: "idle", to: "loading", label: "changeScope(s)", kind: "changeScope", off: 56 },
+    { from: "idle", to: "refreshing", label: "refresh()", kind: "refresh", off: -16 },
+    { from: "refreshing", to: "idle", label: "succeed()", kind: "succeed", off: -16 },
+    { from: "refreshing", to: "error", label: "fail()", kind: "fail", off: 14 },
+    { from: "error", to: "refreshing", label: "refresh()", kind: "refresh", off: 70 },
+  ],
+}
+
+export const calendar: Blueprint = {
+  slug: "calendar",
+  name: "Calendar<Event>",
+  tagline: "A navigable temporal grid of time-bounded events within a scoped viewport.",
+  role: "feature",
+  extendsName: "Set<Event>",
+  composesCount: 2,
+
+  sig: {
+    header: "Calendar<Event> + Async + Pullable",
+    fields: [
+      {
+        name: "members",
+        type: "set CalendarEvent",
+        note: "loaded events for the current viewport",
+      },
+      { name: "scope", type: "Scope", note: "viewport granularity" },
+      { name: "focusDate", type: "Date", note: "anchor date of the viewport" },
+      { name: "loadState", type: "LoadState", note: "Async · Pullable" },
+      {
+        name: "visible",
+        type: "set CalendarEvent",
+        note: "derived: events anchored in the viewport",
+      },
+    ],
+    types: [
+      "Scope     = Day | Week | Month",
+      "LoadState = Idle | Loading | Refreshing | Error",
+      "CalendarEvent  extends Item { startAt, endAt : DateTime }   -- endAt ≥ startAt",
+      "viewportStart = startOf(focusDate, scope)   viewportEnd = endOf(focusDate, scope)",
+      "visible = { e ∈ members | e.startAt ∈ [viewportStart, viewportEnd) }   (derived)",
+    ],
+  },
+
+  functions: [
+    {
+      id: "navigate",
+      name: "Navigate",
+      fig: "01",
+      caps: ["Calendar"],
+      verb: "Advance or retreat focusDate by one scope unit; trigger a fetch for the new viewport range.",
+      state: [
+        ["focusDate", "Date"],
+        ["loadState", "LoadState"],
+      ],
+      behaviors: [
+        {
+          sig: "navigate(delta)",
+          pre: "loadState = Idle",
+          eff: "focusDate ← focusDate ± 1 scope unit, loadState ← Loading",
+        },
+      ],
+      invariants: ["scope ∈ {Day, Week, Month} — viewport always has a defined granularity"],
+      failures: [
+        "navigate during load — navigate() called while loadState = Loading; pre-condition fails, the call must be ignored or queued, never double-fetched",
+      ],
+      perf: [
+        "new viewport renders within 300 ms — pre-fetch adjacent viewports while loadState = Idle",
+      ],
+      notes: [
+        "navigate(+1) advances by one scope unit (e.g. next week when scope = Week); navigate(-1) retreats.",
+      ],
+    },
+    {
+      id: "render",
+      name: "Render",
+      fig: "02",
+      caps: ["Calendar", "Async"],
+      verb: "Position events in their day / time-slot cells; clip multi-day events at the viewport boundary.",
+      state: [
+        ["members", "set CalendarEvent"],
+        ["visible", "set CalendarEvent"],
+      ],
+      behaviors: [],
+      invariants: [
+        "#1  visible ⊆ members — visible never exceeds loaded events",
+        "#2  ∀ e ∈ visible : e.startAt ∈ [viewportStart, viewportEnd) — only events anchored in the viewport are shown",
+        "#4  ∀ e ∈ members : e.endAt ≥ e.startAt — no negative-duration events",
+      ],
+      failures: [
+        "multi-day overflow — event.endAt > viewportEnd; the event must be clipped at viewportEnd in the display, the underlying data not truncated",
+        "timezone mismatch — server returns UTC, client displays local time; events land in the wrong day or hour, so every DateTime must carry a timezone",
+      ],
+      perf: [
+        "60 fps minimum for time-axis scrolling in Day and Week scopes (hour-slot rows must be virtualized)",
+      ],
+      notes: ["visible is always derived — it is never set directly."],
+    },
+    {
+      id: "load",
+      name: "Load",
+      fig: "03",
+      caps: ["Async", "Pullable"],
+      verb: "Fetch events for the current viewport range; reload on every navigate and changeScope; support refresh.",
+      state: [
+        ["loadState", "LoadState"],
+        ["members", "set CalendarEvent"],
+      ],
+      behaviors: [
+        {
+          sig: "refresh()",
+          pre: "loadState = Idle",
+          eff: "loadState ← Refreshing; re-fetch events for the current viewport range",
+        },
+        {
+          sig: "succeed(ev)",
+          pre: "loadState ∈ {Loading, Refreshing}",
+          eff: "members ← ev, loadState ← Idle",
+        },
+        { sig: "fail()", pre: "loadState ∈ {Loading, Refreshing}", eff: "loadState ← Error" },
+      ],
+      invariants: [
+        "#6  members = ∅ is a valid state (empty calendar, not an error)",
+        "#3  events are identity-unique within members",
+      ],
+      failures: [
+        "empty vs error conflation — server returns 0 events with a 4xx status; the empty viewport is treated as an error and the user sees the wrong UI",
+        "stale events after reload — succeed(ev) does not replace members atomically; old and new events coexist and identity-uniqueness is violated",
+      ],
+      perf: [
+        "pre-fetch adjacent viewports while loadState = Idle so navigate() renders within 300 ms",
+      ],
+      notes: [],
+    },
+    {
+      id: "scope",
+      name: "Scope",
+      fig: "04",
+      caps: ["Calendar"],
+      verb: "Switch between Day, Week, and Month granularities without losing focusDate.",
+      state: [
+        ["scope", "Scope"],
+        ["loadState", "LoadState"],
+      ],
+      behaviors: [
+        {
+          sig: "changeScope(s)",
+          pre: "loadState = Idle, s ≠ scope",
+          eff: "scope ← s, loadState ← Loading; fetch events for the new [viewportStart, viewportEnd)",
+        },
+      ],
+      invariants: [
+        "#5  scope ∈ {Day, Week, Month} — viewport always has a defined granularity",
+        "changeScope preserves focusDate",
+      ],
+      failures: [],
+      perf: ["layout recalculates within one frame (≤ 16 ms) for already-loaded events"],
+      notes: [],
+    },
+  ],
+
+  coreInvariants: [
+    "visible ⊆ members — only loaded events can be shown",
+    "∀ e ∈ visible : e.startAt ∈ [viewportStart, viewportEnd) — only viewport-anchored events are shown",
+    "∀ e ∈ members : e.endAt ≥ e.startAt — no negative-duration events",
+    "events are identity-unique within members",
+    "members = ∅ is a valid state (empty calendar, not an error)",
+  ],
+
+  composition: {
+    caps: [
+      { id: "core", label: "Calendar : Set", sub: "members, scope, focusDate", core: true },
+      { id: "async", label: "Async", sub: "loadState" },
+      { id: "pullable", label: "Pullable", sub: "refresh" },
+    ],
+    funcs: ["Navigate", "Render", "Load", "Scope"],
+    links: [
+      ["core", "Navigate"],
+      ["core", "Render"],
+      ["core", "Scope"],
+      ["async", "Render"],
+      ["async", "Load"],
+      ["pullable", "Load"],
+    ],
+  },
+
+  stateMachine: CALENDAR_MACHINE,
+}

src/specimens/CalendarSpecimen.vue

@@ -0,0 +1,526 @@
+<script setup lang="ts">
+import { computed } from "vue"
+
+const props = defineProps<{ activeId: string }>()
+
+const WEEKDAYS = ["Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"]
+
+// A month event bar, placed by (week row, start weekday, day span).
+interface MonthEvent {
+  key: string
+  label: string
+  week: number
+  start: number // 0 = Mon … 6 = Sun
+  span: number // days
+  clip?: boolean // clipped at the viewport boundary
+  skeleton?: boolean
+  hl?: boolean
+  hlTag?: string
+}
+// A week-view event block, placed on the time axis.
+interface WeekEvent {
+  key: string
+  label: string
+  day: number // 0 = Mon … 4 = Fri
+  hour: number // 0-based slot from the first row
+  hl?: boolean
+}
+// Shared header/chrome fields — both scopes have a navigable title + scope toggle.
+interface BaseFrame {
+  title: string
+  scopeActive: "Day" | "Week" | "Month"
+  navHl?: boolean
+  scopeHl?: boolean
+  note?: string
+}
+interface MonthFrame extends BaseFrame {
+  scope: "month"
+  gridHl?: boolean
+  gridTag?: string
+  badge?: string
+  badgeNote?: string
+  events: MonthEvent[]
+}
+interface WeekFrame extends BaseFrame {
+  scope: "week"
+  hours: string[]
+  events: WeekEvent[]
+}
+type Frame = MonthFrame | WeekFrame
+
+// April 2026, laid out as in the ontology README (Mon-first weeks).
+// Leading 30 (Mar) and trailing 1-4 (May) are adjacent-month days.
+const WEEKS: { day: number; adjacent?: boolean }[][] = [
+  [30, 1, 2, 3, 4, 5, 6].map((d, i) => ({ day: d, adjacent: i === 0 })),
+  [7, 8, 9, 10, 11, 12, 13].map((d) => ({ day: d })),
+  [14, 15, 16, 17, 18, 19, 20].map((d) => ({ day: d })),
+  [21, 22, 23, 24, 25, 26, 27].map((d) => ({ day: d })),
+  [28, 29, 30, 1, 2, 3, 4].map((d, i) => ({ day: d, adjacent: i >= 3 })),
+]
+
+// Events used across the month frames.
+const meeting = (extra: Partial<MonthEvent> = {}): MonthEvent => ({
+  key: "meeting",
+  label: "Meeting",
+  week: 0,
+  start: 2,
+  span: 2,
+  ...extra,
+})
+const sprint = (extra: Partial<MonthEvent> = {}): MonthEvent => ({
+  key: "sprint",
+  label: "Sprint review",
+  week: 1,
+  start: 0,
+  span: 1,
+  ...extra,
+})
+const review = (extra: Partial<MonthEvent> = {}): MonthEvent => ({
+  key: "review",
+  label: "Design review",
+  week: 3,
+  start: 1,
+  span: 3,
+  ...extra,
+})
+
+const frame = computed<Frame>(() => {
+  switch (props.activeId) {
+    case "full":
+      return {
+        scope: "month",
+        title: "April 2026",
+        scopeActive: "Month",
+        navHl: true,
+        scopeHl: true,
+        gridHl: true,
+        gridTag: "◈ RENDER",
+        events: [meeting(), sprint(), review()],
+      }
+    case "navigate":
+      return {
+        scope: "month",
+        title: "April 2026",
+        scopeActive: "Month",
+        navHl: true,
+        badge: "loadState = Loading",
+        badgeNote: "navigate(+1) → fetching May 2026…",
+        note: "navigate(+1) advances focusDate by one scope unit (a month here) → loadState ← Loading, viewport re-fetched.",
+        events: [meeting(), sprint(), review()],
+      }
+    case "render":
+      return {
+        scope: "month",
+        title: "April 2026",
+        scopeActive: "Month",
+        gridHl: true,
+        gridTag: "◈ RENDER",
+        note: "visible = { e ∈ members | e.startAt ∈ [viewportStart, viewportEnd) } — the trailing event is clipped at viewportEnd; its data is not truncated.",
+        events: [
+          meeting({ hl: true, hlTag: "spans Wed–Thu" }),
+          sprint(),
+          review(),
+          { key: "overflow", label: "Offsite ▸", week: 4, start: 4, span: 3, clip: true },
+        ],
+      }
+    case "load":
+      return {
+        scope: "month",
+        title: "April 2026",
+        scopeActive: "Month",
+        badge: "loadState = Refreshing",
+        badgeNote: "re-fetching viewport range…",
+        note: "Skeleton bars mirror real event bars so the transition to Idle causes no layout shift. members = ∅ is a valid result, not an error.",
+        events: [
+          meeting({ skeleton: true }),
+          sprint({ skeleton: true }),
+          review({ skeleton: true }),
+        ],
+      }
+    case "scope":
+      return {
+        scope: "week",
+        title: "Week of Apr 21",
+        scopeActive: "Week",
+        scopeHl: true,
+        note: "changeScope(Week) keeps focusDate (Apr 21) and re-fetches the new [viewportStart, viewportEnd) — layout switches to a time axis.",
+        hours: ["09:00", "10:00", "11:00", "12:00"],
+        events: [
+          { key: "standup", label: "Stand-up", day: 0, hour: 0 },
+          { key: "oneone", label: "1:1", day: 4, hour: 0 },
+          { key: "design", label: "Design review", day: 2, hour: 2, hl: true },
+        ],
+      }
+    default:
+      return {
+        scope: "month",
+        title: "April 2026",
+        scopeActive: "Month",
+        events: [meeting(), sprint(), review()],
+      }
+  }
+})
+
+const isMonth = computed(() => frame.value.scope === "month")
+
+function barStyle(e: MonthEvent) {
+  return {
+    left: `calc(${(e.start / 7) * 100}% + 3px)`,
+    width: `calc(${(e.span / 7) * 100}% - 6px)`,
+  }
+}
+</script>
+
+<template>
+  <div class="specimen">
+    <!-- header: scope toggle + navigation -->
+    <div class="cal-head">
+      <div
+        class="nav"
+        :class="frame.navHl ? ['hl', 'tag-b'] : []"
+        :data-tag="frame.navHl ? '◈ NAVIGATE' : undefined"
+      >
+        <span class="arrow">‹</span>
+        <span class="title">{{ frame.title }}</span>
+        <span class="arrow">›</span>
+      </div>
+      <div
+        class="scopes"
+        :class="frame.scopeHl ? ['hl', 'tag-b'] : []"
+        :data-tag="frame.scopeHl ? '◈ SCOPE' : undefined"
+      >
+        <span
+          v-for="s in ['Day', 'Week', 'Month']"
+          :key="s"
+          class="scope-btn"
+          :class="{ on: frame.scopeActive === s }"
+          >{{ s }}</span
+        >
+      </div>
+    </div>
+
+    <div v-if="frame.scope === 'month' && frame.badge" class="spec-toolbar">
+      <span class="badge">{{ frame.badge }}</span>
+      <span v-if="frame.badgeNote" class="badge-note">{{ frame.badgeNote }}</span>
+    </div>
+
+    <p v-if="frame.note" class="note">{{ frame.note }}</p>
+
+    <!-- MONTH grid -->
+    <div
+      v-if="isMonth && frame.scope === 'month'"
+      class="monthbox"
+      :class="frame.gridHl ? ['hl', 'tag-b'] : []"
+      :data-tag="frame.gridTag"
+    >
+      <div class="wd-row">
+        <div v-for="d in WEEKDAYS" :key="d" class="wd">{{ d }}</div>
+      </div>
+      <div v-for="(week, wi) in WEEKS" :key="wi" class="week">
+        <div class="daycells">
+          <div v-for="(c, ci) in week" :key="ci" class="daycell" :class="{ adjacent: c.adjacent }">
+            <span class="dnum">{{ c.day }}</span>
+          </div>
+        </div>
+        <div
+          v-for="e in frame.events.filter((x) => x.week === wi)"
+          :key="e.key"
+          class="ev"
+          :class="{ skeleton: e.skeleton, clip: e.clip, hl: e.hl }"
+          :style="barStyle(e)"
+          :data-tag="e.hlTag"
+        >
+          <span v-if="!e.skeleton" class="ev-label">{{ e.label }}</span>
+        </div>
+      </div>
+    </div>
+
+    <!-- WEEK time-axis grid -->
+    <div v-else-if="frame.scope === 'week'" class="weekbox">
+      <div class="wk-head">
+        <div class="wk-corner" />
+        <div v-for="d in WEEKDAYS.slice(0, 5)" :key="d" class="wk-day">{{ d }}</div>
+      </div>
+      <div v-for="(h, hi) in frame.hours" :key="h" class="wk-row">
+        <div class="wk-hour">{{ h }}</div>
+        <div v-for="di in 5" :key="di" class="wk-cell">
+          <div
+            v-for="e in frame.events.filter((x) => x.day === di - 1 && x.hour === hi)"
+            :key="e.key"
+            class="wk-ev"
+            :class="{ hl: e.hl }"
+          >
+            {{ e.label }}
+          </div>
+        </div>
+      </div>
+    </div>
+  </div>
+</template>
+
+<style scoped>
+.specimen {
+  --ink: var(--color-base-content);
+  --ink-faint: #4f7099;
+  --amber: var(--color-accent);
+  --amber-dim: color-mix(in srgb, var(--color-accent) 14%, transparent);
+  --cyan: var(--color-secondary);
+  --red: var(--color-error);
+  --paper: var(--color-base-100);
+  --line: rgba(200, 226, 255, 0.14);
+  --line-strong: rgba(200, 226, 255, 0.3);
+  font-size: 13px;
+}
+.note {
+  color: var(--ink-faint);
+  font-size: 11px;
+  font-style: italic;
+  margin: 0 0 10px;
+}
+
+/* header */
+.cal-head {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  gap: 10px;
+  margin-bottom: 12px;
+  flex-wrap: wrap;
+}
+.nav {
+  display: flex;
+  align-items: center;
+  gap: 12px;
+  border: 1px solid var(--line);
+  background: var(--paper);
+  padding: 5px 12px;
+}
+.nav .arrow {
+  color: var(--cyan);
+  font-size: 16px;
+  line-height: 1;
+}
+.nav .title {
+  color: var(--ink);
+  letter-spacing: 0.04em;
+}
+.scopes {
+  display: flex;
+  border: 1px solid var(--line);
+}
+.scope-btn {
+  padding: 4px 11px;
+  font-size: 11px;
+  color: var(--ink-faint);
+  border-left: 1px solid var(--line);
+}
+.scope-btn:first-child {
+  border-left: none;
+}
+.scope-btn.on {
+  color: var(--amber);
+  background: var(--amber-dim);
+}
+
+/* toolbar */
+.spec-toolbar {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  margin-bottom: 10px;
+  font-size: 12px;
+}
+.badge {
+  border: 1px solid var(--line-strong);
+  color: var(--cyan);
+  padding: 1px 7px;
+  font-size: 10px;
+  letter-spacing: 0.08em;
+}
+.badge-note {
+  color: var(--ink-faint);
+}
+
+/* month grid */
+.monthbox {
+  border: 1px solid var(--line);
+  background: var(--paper);
+}
+.wd-row {
+  display: grid;
+  grid-template-columns: repeat(7, 1fr);
+  border-bottom: 1px solid var(--line);
+}
+.wd {
+  padding: 5px 6px;
+  font-size: 10px;
+  letter-spacing: 0.1em;
+  text-transform: uppercase;
+  color: color-mix(in srgb, var(--ink) 55%, transparent);
+  text-align: right;
+}
+.week {
+  position: relative;
+  border-bottom: 1px solid var(--line);
+}
+.week:last-child {
+  border-bottom: none;
+}
+.daycells {
+  display: grid;
+  grid-template-columns: repeat(7, 1fr);
+}
+.daycell {
+  min-height: 46px;
+  border-left: 1px dashed var(--line);
+  padding: 4px 6px;
+}
+.daycell:first-child {
+  border-left: none;
+}
+.dnum {
+  font-size: 11px;
+  color: color-mix(in srgb, var(--ink) 70%, transparent);
+}
+.daycell.adjacent .dnum {
+  color: var(--ink-faint);
+  opacity: 0.55;
+}
+/* event bars, positioned over the day cells of their week */
+.ev {
+  position: absolute;
+  top: 22px;
+  height: 18px;
+  display: flex;
+  align-items: center;
+  padding: 0 6px;
+  border: 1px solid var(--cyan);
+  background: color-mix(in srgb, var(--cyan) 16%, transparent);
+  font-size: 10px;
+  color: var(--ink);
+  white-space: nowrap;
+  overflow: hidden;
+}
+.ev-label {
+  overflow: hidden;
+  text-overflow: ellipsis;
+}
+.ev.clip {
+  border-right-style: dashed;
+  border-color: var(--amber);
+  background: var(--amber-dim);
+  color: var(--amber);
+  -webkit-mask-image: linear-gradient(90deg, #000 78%, transparent);
+  mask-image: linear-gradient(90deg, #000 78%, transparent);
+}
+.ev.skeleton {
+  border-style: solid;
+  border-color: var(--line-strong);
+  background: rgba(255, 255, 255, 0.02);
+}
+.ev.skeleton::after {
+  content: "";
+  width: 62%;
+  height: 8px;
+  background: repeating-linear-gradient(
+    90deg,
+    var(--ink-faint),
+    var(--ink-faint) 6px,
+    transparent 6px,
+    transparent 12px
+  );
+  opacity: 0.5;
+}
+
+/* week / time-axis grid */
+.weekbox {
+  border: 1px solid var(--line);
+  background: var(--paper);
+}
+.wk-head,
+.wk-row {
+  display: grid;
+  grid-template-columns: 48px repeat(5, 1fr);
+}
+.wk-head {
+  border-bottom: 1px solid var(--line);
+}
+.wk-corner {
+  border-right: 1px solid var(--line);
+}
+.wk-day {
+  padding: 5px 6px;
+  font-size: 10px;
+  letter-spacing: 0.1em;
+  text-transform: uppercase;
+  color: color-mix(in srgb, var(--ink) 55%, transparent);
+  text-align: center;
+}
+.wk-row {
+  border-bottom: 1px solid var(--line);
+}
+.wk-row:last-child {
+  border-bottom: none;
+}
+.wk-hour {
+  padding: 6px;
+  font-size: 10px;
+  color: var(--ink-faint);
+  border-right: 1px solid var(--line);
+  text-align: right;
+}
+.wk-cell {
+  min-height: 30px;
+  border-left: 1px dashed var(--line);
+  padding: 3px;
+}
+.wk-cell:first-of-type {
+  border-left: none;
+}
+.wk-ev {
+  border: 1px solid var(--cyan);
+  background: color-mix(in srgb, var(--cyan) 16%, transparent);
+  color: var(--ink);
+  font-size: 10px;
+  padding: 2px 5px;
+  white-space: nowrap;
+  overflow: hidden;
+  text-overflow: ellipsis;
+}
+
+/* callouts */
+.hl {
+  outline: 1.5px dashed var(--amber);
+  outline-offset: 3px;
+  position: relative;
+  z-index: 2;
+}
+.hl[data-tag]::after {
+  content: attr(data-tag);
+  position: absolute;
+  top: -10px;
+  left: 8px;
+  background: var(--paper);
+  color: var(--amber);
+  font-size: 9px;
+  padding: 0 5px;
+  border: 1px solid var(--amber);
+  white-space: nowrap;
+  letter-spacing: 0.1em;
+  line-height: 1.5;
+  z-index: 3;
+}
+.hl.tag-b[data-tag]::after {
+  top: auto;
+  bottom: -10px;
+}
+.ev.hl {
+  z-index: 4;
+}
+.wk-ev.hl {
+  outline-color: var(--amber);
+  border-color: var(--amber);
+  background: var(--amber-dim);
+  color: var(--amber);
+}
+</style>