* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}
html {
  font-family: monospace, monospace;
  font-size: 16px;
}
body {
  --body-gap: 1vmin;
  --small-gap: 0.25rem;
  --player-stats-height: 2rem;
  --board-container-padding: 2vmin;
  --board-size: calc( 100vmin - ((2 * var(--player-stats-height)) + (2 * var(--body-gap)) + (4 * var(--board-container-padding))) );
  --glass-shadow: inset 0 -1px 1px rgba(10, 10, 75, 0.75),
                  inset 0  1px 1px rgba(255, 100, 255, 0.5);
  --glass-blur: 3rem;
  --small-border-radius: 0.5vmin;
  --medium-border-radius: 1vmin;
  --large-border-radius: 2.5vmin;
  
  background-color: black;
  display: flex;
  justify-content: center;
  align-items: center;
  flex-direction: column;
  gap: var(--body-gap);
  height: 100vh;
  overflow: hidden;
  background-image: url(/img/background.webp);
  background-size: cover;
  background-position: center;
}

img,
h2,
p {
  user-select: none;
}

h2 {
  font-size: 2rem;
  text-align: center;
  color: white;
}

input,
button {
  font-family: inherit;
  font-size: 1.25rem;
  outline: none;
  border-radius: var(--small-border-radius);
  border: none;
  background-color: rgba(255, 255, 255, 0.5);
}

input {
  padding: 0.5rem;
}
input::placeholder {
  color: #00000080;
}

button {
  cursor: pointer;
  color: black;
}

button:hover {
  background-color: rgba(255, 255, 255, 0.75);
}
button:active {
  background-color: rgb(255, 255, 255);
}



/* ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• Transitions */

#board-container,
#main-menu,
#game-options-menu,
#post-game-menu,
#pawn-promotion-menu,
#loader {
  opacity: 0;
  pointer-events: none;
  filter: blur(1rem);
  
  transition: opacity 350ms cubic-bezier(0.5, 0, 0.5, 1),
            transform 350ms cubic-bezier(0.5, 0, 0.5, 1),
               filter 350ms cubic-bezier(0.5, 0, 0.5, 1);
}


#main-menu,
#loader {
  transform: translateY(-2rem);
}
#game-options-menu,
#post-game-menu {
  transform: translateY(2rem);
}
body.show-post-game-menu #post-game-menu {
  transition-delay: 2s;
}

body.show-main-menu #main-menu,
body.show-game-options-menu #game-options-menu,
body.show-board #board-container,
body.show-post-game-menu #post-game-menu,
body.show-post-game-menu #board-container,
body.show-pawn-promotion-menu #pawn-promotion-menu,
body.show-loader #loader {
  transform: none;
  opacity: 1;
  filter: none;
  pointer-events: initial;
}

/* •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• Loader */
#loader {
  display: flex;
  justify-content: center;
  align-items: center;
  flex-direction: column;
}
#loader > img {
  width: 50%;
  aspect-ratio: 1 / 1;
  animation: vibrate 500ms infinite linear;
}
#loader > p {
  padding: 1rem 0.5rem;
  background-color: rgba(255, 255, 255, 0.25);
  border-radius: var(--small-border-radius);
  animation-delay: 250ms;
}
#loader > button {
  padding: 0.5rem 2rem;
}

@keyframes vibrate {
  0%   { transform: translate(0);                }
  10%  { transform: translate(-0.1rem, -0.1rem); }
  20%  { transform: translate( 0.1rem, -0.1rem); }
  30%  { transform: translate(-0.1rem,  0.1rem); }
  40%  { transform: translate( 0.1rem,  0.1rem); }
  50%  { transform: translate(-0.1rem, -0.1rem); }
  60%  { transform: translate( 0.1rem, -0.1rem); }
  70%  { transform: translate(-0.1rem,  0.1rem); }
  80%  { transform: translate(-0.1rem, -0.1rem); }
  90%  { transform: translate( 0.1rem, -0.1rem); }
  100% { transform: translate(0);                }
}

 
/* ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• Board */
#board-container {
  display: grid;
  position: relative;
  place-items: center;
  border-radius: var(--large-border-radius);
  padding: var(--board-container-padding);
  gap: var(--board-container-padding);
  box-shadow: var(--glass-shadow);
  overflow: hidden;
}


#board {
  position: relative;
  width: var(--board-size);
  height: var(--board-size);
  cursor: grab;
  border-radius: var(--medium-border-radius);
  overflow: hidden;
}
#board:active {
  cursor: grabbing;
}

.board-background {
  position: absolute;
  object-fit: cover;
  width: 100%;
  height: 100%;
  image-rendering: pixelated;
  opacity: 0.125;
}
.hover-outline {
  border: 0.25vmin solid white;
  box-shadow: 0 0 1vmin white,
        inset 0 0 1vmin white;
  opacity: 0;
}

.piece {
  transition: opacity 500ms ease-in-out;
}

.piece,
.hover-outline,
.previous-move-origin-marker,
.previous-move-target-marker {
  position: absolute;
  width: calc(var(--board-size) / 8);
  aspect-ratio: 1 / 1;
}

.piece.in-check {
  background: radial-gradient(circle, red 30%, transparent 75%);
}

.previous-move-origin-marker,
.previous-move-target-marker {
  box-shadow: inset 0 0 7vmin rgb(0, 255, 255);
}

.player-stats {
  width: 100%;
  height: var(--player-stats-height);
  display: flex;
  justify-content: flex-end;
  align-items: center;
  color: white;
}

.player-stats:last-of-type {
  justify-content: space-between;
}

.opponent-clock,
.friendly-clock {
  display: grid;
  place-items: center;
  height: 100%;
  padding: 0 0.5rem;
  border-radius: var(--small-border-radius);
  color: rgba(255, 255, 255, 0.75);
}

.opponent-stats.active-clock .opponent-clock,
.friendly-stats.active-clock .friendly-clock {
  background-color: rgba(255, 255, 255, 0.25);
  color: white;
}

.resign-button-container {
  position: relative;
  height: 100%;
  display: grid;
  place-items: center;
  border-radius: var(--small-border-radius);
  overflow: hidden;
}
.resign-button {
  font-size: 0.75rem;
  height: 100%;
  padding: 0 0.5rem;
  color: white;
  background-color: rgba(255, 255, 255, 0.1);
}
.resign-button:hover {
  background-color: rgb(150, 0, 0);
}
.resign-button:active {
  background-color: rgba(200, 0, 0, 0.8);
}

.resign-button-fill-background {
  position: absolute;
  z-index: -1;
  background-color: red;
  width: 100%;
  height: 100%;
  transform: scaleX(0);
  transform-origin: left;
}
.resign-button:active + .resign-button-fill-background {
  animation: resign-button-animation 2s linear;
}
@keyframes resign-button-animation {
  to { transform: none; }
}




/* ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• Menus */

#main-menu,
#game-options-menu,
#post-game-menu,
#pawn-promotion-menu,
#loader {
  position: absolute;
  width: 18rem;
  height: 18rem;
  overflow: hidden;
  padding: 1rem;
  border-radius: var(--medium-border-radius);
  gap: var(--small-gap);
  z-index: 10;
}

#main-menu {
  display: grid;
  grid-template-rows: repeat(4, 1fr);
}

#main-menu > h2 {
  display: grid;
  place-items: center;
}

#main-menu,
#game-options-menu,
#post-game-menu {

  --row-width: 16rem;
  --col-height: 3rem;
}

#game-options-menu {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

#game-options-menu > h2,
#room-id-input,
.time-control-picker,
.host-color-picker,
.navigation-buttons {
  height: var(--col-height);
}

#room-id-input {
  width: var(--row-width);
}
.alert-shake-animation {
  box-shadow: inset 0 0 0 0.125rem red;
  animation: shake 250ms linear forwards;
}

@keyframes shake {
  0%   { transform: translateX(0);        }
  25%  { transform: translateX(0.75rem);  }
  50%  { transform: translateX(-0.75rem); }
  75%  { transform: translateX(0.35rem);  }
  100% { transform: translateX(0);        }
}

#game-options-menu img {
  padding: 10%;
}

#game-options-menu .navigation-buttons {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--small-gap);
  width: var(--row-width);
}

.host-color-picker,
.time-control-picker {
  background-color: rgba(255, 255, 255, 0.5);
  border-radius: var(--small-border-radius);
  display: grid;
  align-items: center;
}

.host-color-picker {
  grid-template-columns: repeat(3, 1fr);
}

.time-control-picker {
  grid-template-columns: repeat(5, 1fr);
}

.host-color-picker > *,
.time-control-picker > * {
  height: 100%;
  border-radius: var(--small-border-radius);
}

.host-color-picker input,
.time-control-picker input {
  position: absolute;
  opacity: 0;
  width: 0;
  left: -200vmax;
}

.host-color-picker label,
.time-control-picker label {
  display: grid;
  place-items: center;
  cursor: pointer;
  transition: background-color 125ms ease-out;
}


.host-color-picker input:checked + label,
.time-control-picker input:checked + label {
  background-color: white;
}

#post-game-menu {
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  align-items: center;
  color: white;
}

#post-game-menu .top-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

#post-game-menu .top-row,
#post-game-menu .message,
#post-game-menu .button-container {
  width: var(--row-width);
}

#post-game-menu h2 {
  font-size: 1rem;
}

#post-game-menu .countdown {
  position: relative;
  display: grid;
  place-items: center;
  width: 2rem;
  height: 2rem;
}

#post-game-menu .countdown svg {
  position: absolute;
  width: 100%;
  height: 100%;
}

#post-game-menu .countdown-circle {
  stroke-dasharray: 56.5 56.5;
  transition: opacity  1s ease-in 9s,
    stroke-dashoffset 10s linear;
}
body.show-post-game-menu .countdown-circle {
  stroke-dashoffset: -56.5;
  opacity: 0;
}

#post-game-menu .message {
  text-align: center;
}

#post-game-menu .button-container {
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  gap: var(--small-gap);
  height: calc((2 * var(--col-height)) + var(--small-gap));
}
#post-game-menu button {
  padding: 0;
  height: var(--col-height);
}

#pawn-promotion-menu.black-pieces .option .queen  { content: url(/img/bq.svg); }
#pawn-promotion-menu.black-pieces .option .rook   { content: url(/img/br.svg); }
#pawn-promotion-menu.black-pieces .option .bishop { content: url(/img/bb.svg); }
#pawn-promotion-menu.black-pieces .option .knight { content: url(/img/bn.svg); }
#pawn-promotion-menu.black-pieces .cancel-button  { content: url(/img/black-x.svg); }

#pawn-promotion-menu {
  display: grid;
  place-items: center;
  grid-template-columns: 1fr 1fr;
  grid-template-rows: 1fr 1fr;
}
#pawn-promotion-menu .option {
  display: grid;
  place-items: center;
  cursor: pointer;
  border-radius: var(--small-border-radius);
}
#pawn-promotion-menu .option-foreground {
  position: absolute;
  pointer-events: none;
  width: 5rem;
  height: 5rem;
}
#pawn-promotion-menu .option-background {
  opacity: 0.25;
  position: absolute;
  transform-origin: center;
}
#pawn-promotion-menu .option-background:hover {
  opacity: 0.5;
}
#pawn-promotion-menu .option-background:active {
  opacity: 0.75;
}
#pawn-promotion-menu .rook-option   .option-background { transform: rotate(90deg);}
#pawn-promotion-menu .knight-option .option-background { transform: rotate(180deg);}
#pawn-promotion-menu .bishop-option .option-background { transform: rotate(270deg);}


#pawn-promotion-menu .cancel-button {
  position: absolute;
  cursor: pointer;
  background-color: rgba(255, 255, 255, 0.25);
  width: calc(5rem - (var(--small-gap) * 2));
  height: calc(5rem - (var(--small-gap) * 2));
  border-radius: 50%;
}
#pawn-promotion-menu .cancel-button:hover {
  background-color: rgba(255, 255, 255, 0.5);
}
#pawn-promotion-menu .cancel-button:active {
  background-color: rgba(255, 255, 255, 0.75);
}

/* Blur Effect ••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••• */

/* Alignment and background */
.board-container-blur-background,
.board-blur-background,
.main-menu-blur-background,
.game-options-menu-blur-background,
.loader-blur-background,
.post-game-menu-blur-background,
.pawn-promotion-menu-blur-background {
  position: absolute;
  width: 100vw;
  height: 100vh;
  background-image: url(/img/background.webp);
  background-position: center;
  background-size: cover;
  z-index: -1;
}
#board-container::before,
#main-menu::before,
#game-options-menu::before,
#loader::before,
#post-game-menu::before,
#pawn-promotion-menu::before {
  content: "";
  width: 100%;
  height: 100%;
  top: 0;
  left: 0;
  position: absolute;
  pointer-events: none;
  box-shadow: var(--glass-shadow);
  border-radius: var(--medium-border-radius);
}
#board-container::before {
  border-radius: var(--large-border-radius);
}



/* Blur amount */
.board-container-blur-background {
  filter: blur(1rem);
}
.board-blur-background,
.main-menu-blur-background,
.game-options-menu-blur-background,
.loader-blur-background,
.post-game-menu-blur-background,
.pawn-promotion-menu-blur-background {
  filter: blur(3rem);
}

/* Centered */
.board-blur-background,
.main-menu-blur-background,
.game-options-menu-blur-background,
.loader-blur-background,
.post-game-menu-blur-background,
.pawn-promotion-menu-blur-background {
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
}