JSFiddle - React, Tailwind, and code Playground

by qwerew0

HTML

<div class="container">
      <div class="calendar">
        <div class="month">
          <i class="fas fa-angle-left prev"></i>
          <div class="date">
            <h1></h1>
            <p></p>
          </div>
          <i class="fas fa-angle-right next"></i>
        </div>
        <div class="weekdays">
          <div>일</div>
          <div>월</div>
          <div>화</div>
          <div>수</div>
          <div>목</div>
          <div>금</div>
          <div>토</div>
        </div>
        <div class="days"></div>
      </div>
    </div>

CSS

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: "Quicksand", sans-serif;
}

html {
  font-size: 62.5%;
}

.container {
  width: 100%;
  height: 100vh;
  background-color: #12121f;
  color: #eee;
  display: flex;
  justify-content: center;
  align-items: center;
}

.calendar {
  width: 45rem;
  height: 52rem;
  background-color: #222227;
  box-shadow: 0 0.5rem 3rem rgba(0, 0, 0, 0.4);
}

.month {
  width: 100%;
  height: 12rem;
  background-color: #167e56;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 2rem;
  text-align: center;
  text-shadow: 0 0.3rem 0.5rem rgba(0, 0, 0, 0.5);
}

.month i {
  font-size: 2.5rem;
  cursor: pointer;
}

.month h1 {
  font-size: 3rem;
  font-weight: 400;
  text-transform: uppercase;
  letter-spacing: 0.2rem;
  margin-bottom: 1rem;
}

.month p {
  font-size: 1.6rem;
}

.weekdays {
  width: 100%;
  height: 5rem;
  padding: 0 0.4rem;
  display: flex;
  align-items: center;
}

.weekdays div {
  font-size: 1.5rem;
  font-weight: 400;
  letter-spacing: 0.1rem;
  width: calc(44.2rem / 7);
  display: flex;
  justify-content: center;
  align-items: center;
  text-shadow: 0 0.3rem 0.5rem rgba(0, 0, 0, 0.5);
}

.days {
  width: 100%;
  display: flex;
  flex-wrap: wrap;
  padding: 0.2rem;
}

.days div {
  font-size: 1.4rem;
  margin: 0.3rem;
  width: calc(40.2rem / 7);
  height: 5rem;
  display: flex;
  justify-content: center;
  align-items: center;
  text-shadow: 0 0.3rem 0.5rem rgba(0, 0, 0, 0.5);
  transition: background-color 0.2s;
}

.days div:hover:not(.today) {
  background-color: #262626;
  border: 0.2rem solid #777;
  cursor: pointer;
}

.prev-date,
.next-date {
  opacity: 0.5;
}

.today {
  background-color: #167e56;
}

JavaScript

const date = new Date();

const renderCalendar = () => {
  date.setDate(1);

  const monthDays = document.querySelector(".days");

  const lastDay = new Date(
    date.getFullYear(),
    date.getMonth() + 1,
    0
  ).getDate();

  const prevLastDay = new Date(
    date.getFullYear(),
    date.getMonth(),
    0
  ).getDate();

  const firstDayIndex = date.getDay();

  const lastDayIndex = new Date(
    date.getFullYear(),
    date.getMonth() + 1,
    0
  ).getDay();
  //console.log(lastDayIndex);
  const nextDays = 7 - lastDayIndex - 1;

  const months = [
    "1월",
    "2월",
    "3월",
    "4월",
    "5월",
    "6월",
    "7월",
    "8월",
    "9월",
    "10월",
    "11월",
    "12월",
  ];

  document.querySelector(".date h1").innerHTML = months[date.getMonth()];

  document.querySelector(".date p").innerHTML = new Date().toDateString();

  let days = "";

  for (let x = firstDayIndex; x > 0; x--) {
    days += `<div class="prev-date">${prevLastDay - x + 1}</div>`;
  }

  for (let i = 1; i <= lastDay; i++) {
    if (
      i === new Date().getDate() &&
      date.getMonth() === new Date().getMonth()
    ) {
      days += `<div class="today">${i}</div>`;
    } else {
      days += `<div>${i}</div>`;
    }
  }

  for (let j = 1; j <= nextDays; j++) {
    days += `<div class="next-date">${j}</div>`;
  }
  monthDays.innerHTML = days;
};

document.querySelector(".prev").addEventListener("click", () => {
  date.setMonth(date.getMonth() - 1);
  renderCalendar();
});

document.querySelector(".next").addEventListener("click", () => {
  date.setMonth(date.getMonth() + 1);
  renderCalendar();
});

renderCalendar();