calendar/src/components/CalendarDay.vue

<script setup>
import { computed, ref, onMounted, onBeforeUnmount } from 'vue'
import { fromLocalString } from '@/utils/date'

const props = defineProps({
  day: Object,
  dragging: { type: Boolean, default: false },
})

// Reactive viewport width detection
const isNarrowView = ref(false)
const isVeryNarrowView = ref(false)
const isSmallView = ref(false)

function checkViewportWidth() {
  const width = window.innerWidth
  isSmallView.value = width < 800
  isNarrowView.value = width < 600
  isVeryNarrowView.value = width < 400
}

onMounted(() => {
  checkViewportWidth()
  window.addEventListener('resize', checkViewportWidth)
})

onBeforeUnmount(() => {
  window.removeEventListener('resize', checkViewportWidth)
})

const formattedDate = computed(() => {
  const date = fromLocalString(props.day.date)
  
  let options = { day: 'numeric', month: 'short' }
  
  if (isVeryNarrowView.value) {
    // Very narrow: show only day number
    options = { day: 'numeric' }
  } else if (isNarrowView.value) {
    // Narrow: show day and month, no weekday
    options = { day: 'numeric', month: 'short' }
  } else {
    // Wide: show weekday, day, and month
    options = { weekday: 'short', day: 'numeric', month: 'short' }
  }
  
  let formatted = date.toLocaleDateString(undefined, options)
  
  // Below 700px, replace first space with newline to force weekday on separate line
  if (isSmallView.value && !isNarrowView.value && !isVeryNarrowView.value) {
    formatted = formatted.replace(/\s/, '\n')
  }
  
  // Replace the last space (between month and day) with nbsp to prevent breaking there
  // but keep the space after weekday (if present) as regular space to allow wrapping
  formatted = formatted.replace(/\s+(?=\S+$)/, '\u00A0')
  
  return formatted
})
</script>

<template>
  <div
    class="cell"
    :style="props.dragging ? 'touch-action:none;' : 'touch-action:pan-y;'"
    :class="[props.day.monthClass, { today: props.day.isToday, weekend: props.day.isWeekend, firstday: props.day.isFirstDay, selected: props.day.isSelected, holiday: props.day.isHoliday }]"
    :data-date="props.day.date"
  >
    <span class="compact-date">{{ formattedDate }}</span>
    <h1 class="day-number">{{ props.day.displayText }}</h1>
    <span v-if="props.day.lunarPhase" class="lunar-phase">{{ props.day.lunarPhase }}</span>
    <div v-if="props.day.holiday" class="holiday-info" dir="auto" :title="props.day.holiday.name">
      {{ props.day.holiday.name }}
    </div>
  </div>
</template>

<style scoped>
.cell {
  position: relative;
  user-select: none;
  display: grid;
  grid-template-columns: 1fr;
  grid-template-rows: 1fr auto;
  grid-template-areas:
    'day-number'
    'holiday-info';
  padding: 0.25em;
  overflow: visible;
  width: 100%;
  height: var(--row-h);
  font-weight: 700;
  transition: background-color 0.15s ease;
  align-items: center;
  justify-items: center;
}
.cell h1.day-number {
  position: absolute;
  font-size: 5vmin;
  font-weight: 800;
  color: var(--ink);
  transition: all 0.15s ease;
}
.cell.firstday h1.day-number {
  font-weight: 400;
}
.cell.weekend h1.day-number {
  color: var(--weekend);
}
.cell.firstday h1.day-number {
  color: var(--firstday);
}
.cell.today::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: calc(100% + .2rem);
  height: calc(100% + .2rem);
  border-radius: 1rem;
  background: transparent;
  border: 0.3em solid var(--today);
  z-index: 15;
  pointer-events: none;
}

/* Search highlight animation */
.cell.search-highlight-flash::after {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: calc(100% + .2rem);
  height: calc(100% + .2rem);
  border-radius: 1rem;
  background: transparent;
  border: 0.3em solid var(--strong);
  z-index: 16;
  pointer-events: none;
}

.cell.search-highlight-flash::after { animation: search-highlight-flash 1.5s ease-out forwards; }

@keyframes search-highlight-flash {0%{opacity:0;transform:translate(-50%,-50%) scale(.8);border-width:.1em}15%{opacity:1;transform:translate(-50%,-50%) scale(1.05);border-width:.4em}30%{opacity:1;transform:translate(-50%,-50%) scale(1);border-width:.3em}100%{opacity:0;transform:translate(-50%,-50%) scale(1);border-width:.3em}}
.cell.selected h1.day-number {
  opacity: 0.3;
  filter: brightness(1.2);
}
.cell {
  background-image: linear-gradient(
    135deg,
    var(--holiday-grad-start, rgba(255, 255, 255, 0.3)) 0%,
    var(--holiday-grad-end, rgba(255, 255, 255, 0)) 70%
  );
}
@media (prefers-color-scheme: dark) {
  .cell {
    background-image: linear-gradient(
      135deg,
      var(--holiday-grad-start, rgba(255, 255, 255, 0.05)) 0%,
      var(--holiday-grad-end, rgba(255, 255, 255, 0)) 70%
    );
  }
}
.lunar-phase {
  grid-area: lunar-phase;
  position: absolute;
  inset-block-start: 0.5em;
  inset-inline-end: 0.2em;
  font-size: 0.8em;
  opacity: 0.7;
}

.compact-date {
  position: absolute;
  top: 0.25em;
  left: 0.25em;
  inset-inline-end: 1rem; /* Space for lunar phase */
  font-weight: 400;
  color: var(--ink);
  line-height: 1;
  pointer-events: none;
  white-space: pre-wrap;
}

.cell.weekend .compact-date {
  color: var(--weekend);
}
.cell.firstday .compact-date {
  color: var(--firstday);
}
.cell.today .compact-date {
  color: var(--strong);
}
.cell.selected .compact-date {
  color: var(--strong);
}

.holiday-info {
  grid-area: holiday-info;
  align-self: end;
  overflow: hidden;
  max-width: 100%;
  color: var(--holiday);
  font-size: 1em;
  font-weight: 400;
  line-height: 1.0;
  padding-inline: 0.15em;
  padding-block: 0;
  pointer-events: auto;
}
</style>