01Calendar drag range select

<main class="stage">
  <div class="cal is-demo">
    <div class="cal__head">Sep</div>
    <div class="cal__grid" role="grid" aria-label="Select date range">
      <div class="cal__dow" aria-hidden="true">Sun</div>
      <div class="cal__dow" aria-hidden="true">Mon</div>
      <div class="cal__dow" aria-hidden="true">Tue</div>
      <div class="cal__dow" aria-hidden="true">Wed</div>
      <div class="cal__dow" aria-hidden="true">Thu</div>
      <div class="cal__dow" aria-hidden="true">Fri</div>
      <div class="cal__dow" aria-hidden="true">Sat</div>
    </div>
    <div class="cal__days" role="rowgroup"></div>
  </div>
</main>

@use "../../../../site/static/demo-tokens" as *;

// ── 변수 3개 ──────────────────────────────
$duration: $dur-quick;
$easing: $ease-pop;
$color: $subject-pink;

@include stage($stage-paper);

.cal { position: relative; width: min(304px, 88vw); color: $subject-ink; }
.cal__head {
  font-weight: 700; font-size: 13px; margin-bottom: $sp-2; color: rgba($subject-ink, .7);
}
.cal__grid, .cal__row {
  display: grid; grid-template-columns: repeat(7, 1fr); gap: $sp-1;
}
.cal__dow {
  text-align: center; font-size: 11px; font-weight: 600; color: rgba($subject-ink, .72);
  padding-bottom: $sp-1;
}
.cal__days { position: relative; margin-top: $sp-1; }
.cal__row { position: relative; }
.cal__day {
  appearance: none; border: 0; background: transparent; font: inherit; font-family: inherit;
  width: 100%; aspect-ratio: 1; border-radius: $r-sm; cursor: pointer;
  font-size: 12px; color: $subject-ink; position: relative; z-index: 1;
  transition: background-color $duration $easing, color $duration $easing, transform $duration $easing;
  -webkit-tap-highlight-color: transparent;
}
.cal__day:focus-visible { outline: 2px solid $color; outline-offset: 2px; }
.cal__day.is-range { background: rgba($color, .18); }
.cal__day.is-edge {
  background: $color; color: $subject-ink; font-weight: 700; transform: scale(1.06);
}

@media (prefers-reduced-motion: reduce) {
  .cal__day { transition: none; }
}

html, body {
  margin: 0;
  overflow: hidden;
}

.stage {
  box-sizing: border-box;
  min-height: 100vh;
  display: grid;
  place-items: center;
  margin: 0;
  background: #ffffff;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  padding: clamp(8px, 4vw, 24px);
}

.cal {
  position: relative;
  width: min(304px, 88vw);
  color: #17141a;
}

.cal__head {
  font-weight: 700;
  font-size: 13px;
  margin-bottom: 8px;
  color: rgba(23, 20, 26, 0.7);
}

.cal__grid, .cal__row {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  gap: 4px;
}

.cal__dow {
  text-align: center;
  font-size: 11px;
  font-weight: 600;
  color: rgba(23, 20, 26, 0.72);
  padding-bottom: 4px;
}

.cal__days {
  position: relative;
  margin-top: 4px;
}

.cal__row {
  position: relative;
}

.cal__day {
  appearance: none;
  border: 0;
  background: transparent;
  font: inherit;
  font-family: inherit;
  width: 100%;
  aspect-ratio: 1;
  border-radius: 8px;
  cursor: pointer;
  font-size: 12px;
  color: #17141a;
  position: relative;
  z-index: 1;
  transition: background-color 220ms cubic-bezier(0.2, 1.4, 0.4, 1), color 220ms cubic-bezier(0.2, 1.4, 0.4, 1), transform 220ms cubic-bezier(0.2, 1.4, 0.4, 1);
  -webkit-tap-highlight-color: transparent;
}

.cal__day:focus-visible {
  outline: 2px solid #ff9ebb;
  outline-offset: 2px;
}

.cal__day.is-range {
  background: rgba(255, 158, 187, 0.18);
}

.cal__day.is-edge {
  background: #ff9ebb;
  color: #17141a;
  font-weight: 700;
  transform: scale(1.06);
}

@media (prefers-reduced-motion: reduce) {
  .cal__day {
    transition: none;
  }
}

(function () {
  var cal = document.querySelector('.cal');
  var days = document.createElement('div');
  days.className = 'cal__row';
  var cells = [];
  for (var d = 1; d <= 21; d++) {
    var b = document.createElement('button');
    b.type = 'button'; b.className = 'cal__day'; b.textContent = d;
    b.setAttribute('role', 'gridcell');
    b.setAttribute('aria-selected', 'false');
    b.tabIndex = d === 1 ? 0 : -1;
    b.dataset.day = d;
    days.appendChild(b); cells.push(b);
  }
  cal.querySelector('.cal__days').appendChild(days);

  var start = null, end = null;
  function paint() {
    cells.forEach(function (c) {
      var n = +c.dataset.day;
      var inRange = start && end && n >= start && n <= end;
      var isEdge = n === start || n === end;
      c.classList.toggle('is-range', !!inRange);
      c.classList.toggle('is-edge', isEdge);
      c.setAttribute('aria-selected', isEdge ? 'true' : 'false');
    });
  }
  function pick(n) {
    if (start === null || (start !== null && end !== null)) { start = n; end = null; }
    else { if (n < start) { end = start; start = n; } else { end = n; } }
    paint();
  }
  cells.forEach(function (c, i) {
    c.addEventListener('click', function () { stop(); pick(+c.dataset.day); });
    c.addEventListener('keydown', function (e) {
      var map = { ArrowRight: 1, ArrowLeft: -1, ArrowDown: 7, ArrowUp: -7 };
      if (map[e.key] !== undefined) {
        e.preventDefault(); stop();
        var next = cells[Math.min(cells.length - 1, Math.max(0, i + map[e.key]))];
        cells.forEach(function (x) { x.tabIndex = -1; });
        next.tabIndex = 0; next.focus({ preventScroll: true });
      } else if (e.key === 'Enter' || e.key === ' ') {
        e.preventDefault(); stop(); pick(+c.dataset.day);
      }
    });
  });

  var demoPairs = [[3, 8], [10, 15], [5, 6], [13, 19]];
  var pi = 0;
  function tick() { var pr = demoPairs[pi % demoPairs.length]; start = pr[0]; end = pr[1]; paint(); pi++; }
  var t = setInterval(tick, 500); tick();
  function stop() { cal.classList.remove('is-demo'); clearInterval(t); }
}());

import { useState } from "react";
import type { CSSProperties } from "react";
import styles from "./DateRangeCalendarSelect.module.scss";

export type DateRangeCalendarSelectProps = {
  month?: string;
  dow?: string[];
  days?: number;
  duration?: number;
  easing?: string;
  color?: string;
};

type Vars = CSSProperties & { "--duration"?: string; "--easing"?: string; "--c"?: string };

export default function DateRangeCalendarSelect({
  month = "Sep",
  dow = ["Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"],
  days = 21,
  duration = 220,
  easing = "cubic-bezier(.2,1.4,.4,1)",
  color = "#ff9ebb",
}: DateRangeCalendarSelectProps) {
  const [start, setStart] = useState<number | null>(3);
  const [end, setEnd] = useState<number | null>(8);
  const vars: Vars = { "--duration": `${duration}ms`, "--easing": easing, "--c": color };

  function pick(n: number) {
    if (start === null || (start !== null && end !== null)) {
      setStart(n); setEnd(null);
    } else if (n < start) {
      setEnd(start); setStart(n);
    } else {
      setEnd(n);
    }
  }

  return (
    <div className={styles.cal} style={vars}>
      <div className={styles.head}>{month}</div>
      <div className={styles.grid}>
        {dow.map((d) => (
          <div key={d} className={styles.dow}>{d}</div>
        ))}
      </div>
      <div className={styles.row}>
        {Array.from({ length: days }, (_, i) => i + 1).map((n, i) => {
          const inRange = start !== null && end !== null && n >= start && n <= end;
          const isEdge = n === start || n === end;
          return (
            <button
              key={n}
              type="button"
              className={styles.day}
              data-range={inRange}
              data-edge={isEdge}
              aria-selected={isEdge}
              tabIndex={i === 0 ? 0 : -1}
              onClick={() => pick(n)}
            >
              {n}
            </button>
          );
        })}
      </div>
    </div>
  );
}