span.sprint-letter {
  position: absolute;
  top: 0;
  left: 0.5em;
  font-size: 0.6em;
  color: white;
}

.day>span.label {
  text-transform: uppercase;
  font-size: 0.75em;
}

.day.sprint.today:after {
  display: none;
}

.day.sprint:before {
  background-color: #0000001c;
  right: 0;
  width: 1px;
  top: 0;
  height: 100%;
  position: absolute;
  content: "";
}

span.day-number {
  flex-grow: 1;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
}

@property --darkness {
  syntax: "<percentage>";
  initial-value: 13%;
  inherits: false;
}

@property --lightness {
  syntax: "<percentage>";
  initial-value: 37%;
  inherits: false;
}

@keyframes fadeIn {
  0% {
    --darkness: 18%;
    --lightness: 32%;
  }

  100% {
    --darkness: 10%;
    --lightness: 42%;
  }
}

html body {
  margin: 0;
  height: 100vh;
}

body {
  display: flex;
  align-items: center;
  justify-content: center;
  animation: 20s fadeIn ease-in-out infinite;
  animation-direction: alternate;
  background: linear-gradient(45deg,
      hsl(294deg 25% var(--darkness)) 15%,
      hsl(294deg 25% 19%) 50%,
      hsl(330deg 34% 29%) 50%,
      hsl(330deg 37% var(--lightness)) 85%);
}

body>div {
  background: linear-gradient(135deg, hsl(0deg 0% 91%) 0%, hsl(0deg 0% 78%) 100%);
  padding: 2em;
  border-radius: 0.5rem;
  margin-top: 0;
  box-shadow: 15px 15px 15px #0000000f;
  border-bottom: #666666 0.25rem solid;
}

ul {
  list-style: none;
  padding: 0;
}

body>div>h1,
h1 {
  text-align: center;
  margin-bottom: 0.5em !important;
  font-weight: 100;
  color: #383838;
  font-size: 3rem !important;
}

.calendar-headers {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr 1fr 1fr 1fr 1fr;
  grid-gap: 0.5em 0;
  margin-bottom: 0.5em;
  font-weight: bold;
  padding: 0 0.5em;
}

.header {
  color: #505050;
  font-size: 1em;
  text-transform: uppercase;
  padding: 0.5em 0.5em 0.5em 0;
  text-align: right;
  font-weight: 400;
}

.calendar-container {
  font-size: 1rem;
}

.calendar {
  --cal-grid-space: 0.75em;
  --cal-full-pct: (100% - (var(--cal-grid-space) * 2));
  --cal-sun-left: calc((var(--cal-full-pct) / 7 * 0) + var(--cal-grid-space));
  --cal-mon-left: calc((var(--cal-full-pct) / 7 * 1) + var(--cal-grid-space));
  --cal-tue-left: calc((var(--cal-full-pct) / 7 * 2) + var(--cal-grid-space));
  --cal-wed-left: calc((var(--cal-full-pct) / 7 * 3) + var(--cal-grid-space));
  --cal-thu-left: calc((var(--cal-full-pct) / 7 * 4) + var(--cal-grid-space));
  --cal-fri-left: calc((var(--cal-full-pct) / 7 * 5) + var(--cal-grid-space));
  --cal-sat-left: calc((var(--cal-full-pct) / 7 * 6) + var(--cal-grid-space));
  --cal-sat-right: calc((var(--cal-full-pct) / 7 * 7) + var(--cal-grid-space));
  display: grid;
  grid-template-columns: 1fr 1fr 1fr 1fr 1fr 1fr 1fr;
  grid-gap: var(--cal-grid-space) 0;
  padding: var(--cal-grid-space);
  border-radius: 0.5rem;
  --calendar-white: hsl(0deg 0% 73%);
  --calendar-black: hsl(0deg 0% 65%);
  background: linear-gradient(90deg,
      var(--calendar-white) var(--cal-sun-left),
      var(--calendar-white) var(--cal-mon-left),
      var(--calendar-black) var(--cal-mon-left),
      var(--calendar-black) var(--cal-tue-left),
      var(--calendar-white) var(--cal-tue-left),
      var(--calendar-white) var(--cal-wed-left),
      var(--calendar-black) var(--cal-wed-left),
      var(--calendar-black) var(--cal-thu-left),
      var(--calendar-white) var(--cal-thu-left),
      var(--calendar-white) var(--cal-fri-left),
      var(--calendar-black) var(--cal-fri-left),
      var(--calendar-black) var(--cal-sat-left),
      var(--calendar-white) var(--cal-sat-left),
      var(--calendar-white) var(--cal-sat-right));
}

.day {
  position: relative;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  padding: 0.5em 0.5em 0.5em 0;
  justify-content: space-between;
  min-width: 4.4em;
  min-height: 3.5em;
  align-items: flex-end;
  line-height: 1em;
}

.day.sprint {
  border-radius: 0;

  --bottom-pct: calc(100% - 0.25em);
  background: linear-gradient(180deg,
      hsl(0deg 0% 0% / 0%) var(--bottom-pct),
      hsl(0deg 0% 0% / 14%) var(--bottom-pct),
      hsl(0deg 0% 0% / 13%) 100%);
  background-color: hsl(0deg 0% 96%);
  box-shadow: 0.125rem 0.125rem 0 0 hsl(0deg 0% 60%);
}

.off-month {
  color: gray;
}

.day.sprint.start {
  color: white;
  background-color: hsl(106deg 40% 37%);
  border-radius: 0.25rem 0 0 0.25rem;
  margin-left: 0.5em;
}

.day.sat.sprint:before,
.day.sprint.start:before,
.day.sprint.end:before {
  display: none;
}

.day.today {
  color: hsl(0deg 0% 80%);
  background: linear-gradient(217deg, #646363, #2e2e2e);
  background-size: 400% 400%;
  animation: today-bg-scroll 7s ease infinite;
}

.day.today:before {
  display: none;
}

@keyframes today-bg-scroll {
  0% {
    background-position: 0% 50%;
  }

  50% {
    background-position: 100% 50%;
  }

  100% {
    background-position: 0% 50%;
  }
}

* {
  --border-dark: #a1a1a1;
  --border-light: #bdbdbd;
}

.day.sprint.end {
  color: white;
  border-radius: 0 0.25rem 0.25rem 0;
  background-color: hsl(0deg 40% 53%);
  margin-right: 0.5em;
}

.day.sun.sprint {
  border-radius: 0.25rem 0 0 0.25rem;
  margin-left: -1em;
}

.day.sun.sprint:after {
  content: '⮞';
  position: absolute;
  top: 0;
  left: 0;
  width: 1rem;
  background-color: #0000001d;
  height: 100%;
  display: flex;
  flex-direction: column;
  align-content: center;
  justify-content: center;
  color: var(--border-dark);
  align-items: center;
  font-size: 0.5em;
}

.day.sat.sprint {
  border-radius: 0 0.25rem 0.25rem 0;
  padding-right: 1.5em;
  margin-right: -1em;
}

.day.sat.sprint:after {
  content: '⮞';
  position: absolute;
  top: 0;
  right: 0;
  width: 1rem;
  background-color: #0000001d;
  height: 100%;
  display: flex;
  flex-direction: column;
  align-content: center;
  justify-content: center;
  color: var(--border-dark);
  align-items: center;
  font-size: 0.5em;
}