body {
  width: 100vw;
  height: 100vh;
  margin: 0;
  font-family: Arial;
  background-color: black;
}

hr {
  margin: 2em 0;
}

#pageContainer {
  width: 100%;
  height: 100%;
  display: flex;
}

#calendar {
  width: 15%;
  margin: auto;
  border-style: solid;
  border-color: #a9a9a9;
  border-width: 2px;
  border-radius: 16px;
  overflow: hidden;
  background-color: white;
  font-family: "Segoe UI", Tahoma, Arial;
}

#calendarHeader {
  display: flex;
  flex-direction: row;
  gap: 7%;
  justify-content: center;
  text-align: right;
  padding: 0.75em 4px;
  background: linear-gradient(
    180deg,
    rgba(255, 255, 255, 1) 0%,
    rgba(191, 191, 191, 1) 100%
  );
  line-height: 0;
}

#month select {
  height: 30px;
  text-align: right;
}

#month option {
  direction: rtl;
}

#year {
  display: flex;
  flex-direction: row;
  gap: 1vw;
}

#yearSelector {
  height: 30px;
}

#yearSelector input {
  height: 24px;
}

#goToYear {
  position: relative;
}

#goToYearIcon {
  position: relative;
  cursor: pointer;
  height: 30px;
  z-index: 2;
}

#goToYearIcon.inactive {
  filter: grayscale(1);
  cursor: not-allowed;
}

#goToYearIcon:hover {
  filter: brightness(0.9);
}
#goToYearIcon:active {
  filter: brightness(0.75);
}

#goToYearShadow {
  position: absolute;
  width: 160%;
  height: 160%;
  transform: translate(-18.75%, -18.75%);
  filter: opacity(0);
}

#goToYearShadow.animated {
  animation-name: goToYearBlinking;
  animation-duration: 2s;
  animation-iteration-count: infinite;
  animation-timing-function: ease-in-out;
  filter: opacity(0.33);
}

@keyframes goToYearBlinking {
  0% {
    filter: opacity(0);
  }
  50% {
    filter: opacity(0.9);
  }
  100% {
    filter: opacity(0);
  }
}

#calendarBody {
  padding: 0.5em 4px;
}

#days {
  display: grid;
  grid-template-columns: repeat(7, calc(100% / 7));
  text-align: center;
  row-gap: 0.2em;
}

#days div {
  padding: 0.3em 0;
}

.active {
  background-color: #add7e6;
}

.inactive {
  color: rgb(175, 175, 175);
}

#seventh {
  cursor: pointer;
}

#seventh.inactive {
  cursor: auto;
  color: black;
}

#cornerButton {
  position: absolute;
  top: 3%;
  right: 16vw;
  color: white;
  font-family: "Courier New";
  font-size: 0.9rem;
  padding: 0.5em;
  border-style: solid;
  border-color: white;
  border-width: 1px;
  z-index: 4;
}

#cornerButton:hover {
  cursor: pointer;
}

#cornerButton.hidden {
  visibility: hidden;
}

#menu {
  position: absolute;
  width: 50%;
  left: 25%;
  z-index: 3;
  height: 100%;
  background-color: black;
  filter: opacity(1);
  transition:
    filter 0.5s,
    visibility 0.5s;
  visibility: visible;
}

#about {
  padding-top: 3%;
  text-align: center;
  margin: auto;
  color: white;
  line-height: 1.5em;
}

#about img {
  width: 80%;
  margin: 0 auto;
}

#about a {
  color: #add7e6;
}
#about a:visited {
  color: #556972;
}

#chapterIndex {
  text-align: left;
  line-height: 2em;
}

#chapterIndex a {
  color: white;
  text-decoration: none;
}
#chapterIndex a:hover {
  text-decoration: underline;
}
#chapterIndex a:visited {
  color: white;
}

#aboutText {
  display: flex;
  flex-direction: row;
  gap: 4%;
}

#tutorial {
  text-align: left;
  width: 58%;
  align-self: flex-end;
}

#credits {
  text-align: right;
  width: 38%;
  align-self: flex-end;
}

.inactiveMenu {
  filter: opacity(0) !important;
  visibility: hidden !important;
}

@media screen and (max-width: 1600px) {
  #calendar {
    width: 18%;
  }
}

@media screen and (max-width: 1330px) {
  #calendar {
    width: 20%;
  }
}

@media screen and (max-width: 1200px) {
  #calendar {
    width: 25%;
  }
}

@media screen and (max-width: 950px) {
  #calendar {
    width: 30%;
  }
}

@media screen and (max-width: 790px) {
  #calendar {
    width: 40%;
  }
  #year {
    gap: 2.5vw;
  }
}

@media screen and (max-width: 580px) {
  #calendar {
    width: 60%;
  }
}

@media screen and (max-width: 400px) {
  #calendar {
    width: 80%;
  }
}

@media screen and (orientation: portrait) {
  #cornerButton {
    right: 5vw;
  }

  #menu {
    width: 95%;
    left: 2.5%;
  }
}