:root {
  --font-sans: Arial, "Hiragino Sans GB", "Microsoft Yahei", "微软雅黑",
    sans-serif;
  --font-serif: "Roboto", Georgia, "Times New Roman", Times, "SimSun", "宋体",
    serif;
}

body {
  font-size: 14px;
}

* {
  box-sizing: border-box;
}

.calendar-container {
  display: flex;
  flex-flow: row wrap;
  padding: 1rem 0.5rem 1rem 1.5rem;
  width: 100vw;
  position: relative;
  font-family: var(--font-serif);
}

.cal-header {
  flex: 1 100%;
  font-size: 2rem;
  font-family: "Open Sans", sans-serif;
  font-weight: bold;
  margin-top: 2rem;
  margin-bottom: 2rem;
  margin-left: 0.7rem;
  text-transform: uppercase;
}

.cal-body {
  display: flex;
  flex-wrap: wrap;
  margin-bottom: 1.5rem;
}

.cal-month,
.cal-day {
  font-family: var(--font-serif);
  margin: 0.5rem;
  padding: 0.3rem;
  width: 1.4rem;
  height: 1.4rem;
  display: flex;
  justify-content: center;
  align-items: center;
  font-size: 1.1rem;
}

.cal-month {
  font-weight: bold;
}

.past {
  border-radius: 100%;
  background: black;
}

.cal-footer {
  margin-right: 1.4rem;
  font-size: 0.8rem;
  flex: 1 100%;
  text-align: right;
}

.today {
  position: relative;
  background-color: #fff;
}
.today:after {
  border: 0.25em solid red;
  border-top: none;
  border-radius: 1.5em 1em 2em 1.5em;
  bottom: -0.3em;
  content: "";
  left: -0.3em;
  position: absolute;
  right: -0.3em;
  top: -0.1em;
}
.today:before {
  border-radius: 0.5em;
  content: "";
  height: 1em;
  left: 0;
  position: absolute;
  top: -0.3em;
  transform: rotate(-10deg);
  width: 2em;
}

@media (max-width: 480px) {
  html {
    font-size: 10px;
  }
  .calendar-container {
    margin: 0;
    padding: 10px;
  }

  .cal-header {
    width: 100%;
    margin-top: 10px;
    margin-bottom: 20px;
  }

  .cal-month,
  .cal-day {
    margin: 5px;
    padding: 3px;
  }
}