/* Variables */
:root {
  --orange: #ffa600;
  --green: #c1d72e;
  --blue: #82d2e5;
  --grey: #f3f3f3;
  --white: #fff;
  --base-color: var(--blue);
}

/* Mixins */
.transition {
  -webkit-transition: all 0.5s ease-in-out;
  -moz-transition: all 0.5s ease-in-out;
  transition: all 0.5s ease-in-out;
}

.corners {
  -moz-border-radius: 5px;
  -webkit-border-radius: 5px;
  border-radius: 5px;
  -khtml-border-radius: 5px;
}

body {
  background: var(--base-color);
  font-family: "HelveticaNeue-Light", "Helvetica Neue Light", "Helvetica Neue", Helvetica, Arial, "Lucida Grande", sans-serif;
  height: 100%;
  color: var(--white);
  text-align: center;
}

h1, h2 {
  font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  font-weight: 100;
  font-size: 2.6em;
  text-transform: uppercase;
}

h3 {
  font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  font-weight: 100;
  font-size: 1.4em;
  text-transform: uppercase;
}

#seconds, #tens {
  font-size: 2em;
}

button {
  -moz-border-radius: 5px;
  -webkit-border-radius: 5px;
  border-radius: 5px;
  -khtml-border-radius: 5px;
  background: var(--base-color);
  color: var(--white);
  border: solid 1px var(--white);
  text-decoration: none;
  cursor: pointer;
  font-size: 1.2em;
  padding: 18px 10px;
  width: 180px;
  margin: 10px;
  outline: none;
}

button:hover {
  -webkit-transition: all 0.5s ease-in-out;
  -moz-transition: all 0.5s ease-in-out;
  transition: all 0.5s ease-in-out;
  background: var(--white);
  border: solid 1px var(--white);
  color: var(--base-color);
}

#container {
  width: 630px;
  margin: 10px auto;
}

#container:after {
  content: "";
  display: table;
  clear: both;
}

[data-view="card"] {
  transform: rotateY(180deg);
  width: 100px;
  height: 140px;
  border: solid 1px #d3cece;
  border-radius: 5px;
  float: left;
  margin: 10px;
  cursor: pointer;
  background: linear-gradient(135deg, var(--grey) 22px, var(--white) 22px, var(--white) 24px, transparent 24px, transparent 67px, var(--white) 67px, var(--white) 69px, transparent 69px),
    linear-gradient(225deg, var(--grey) 22px, var(--white) 22px, var(--white) 24px, transparent 24px, transparent 67px, var(--white) 67px, var(--white) 69px, transparent 69px) 0 64px;
  background-color: var(--grey);
  background-size: 64px 128px;
}

.flipped {
  transition: 0.6s;
  transform-style: preserve-3d;
  position: relative;
  transform: rotateY(0deg);
}

.reverse {
  transition: 0.6s;
  transform-style: preserve-3d;
  position: relative;
  transform: rotateY(180deg);
}

.correct {
  opacity: 0.5;
  cursor: default;
  transform-style: preserve-3d;
  position: relative;
  transform: rotateY(0deg);
}

/* Icons */
.correct[data-item="sass"],
.flipped[data-item="sass"] {
  background: var(--white);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 3em;
  color: var(--base-color);
}

.correct[data-item="sass"]::before,
.flipped[data-item="sass"]::before {
  content: "🧵";
}

.correct[data-item="gulp"],
.flipped[data-item="gulp"] {
  background: var(--white);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 3em;
  color: var(--base-color);
}

.correct[data-item="gulp"]::before,
.flipped[data-item="gulp"]::before {
  content: "🍹";
}

.correct[data-item="grunt"],
.flipped[data-item="grunt"] {
  background: var(--white);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 3em;
  color: var(--base-color);
}

.correct[data-item="grunt"]::before,
.flipped[data-item="grunt"]::before {
  content: "🐗";
}

.correct[data-item="git"],
.flipped[data-item="git"] {
  background: var(--white);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 3em;
  color: var(--base-color);
}

.correct[data-item="git"]::before,
.flipped[data-item="git"]::before {
  content: "🐙";
}

.correct[data-item="css"],
.flipped[data-item="css"] {
  background: var(--white);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 3em;
  color: var(--base-color);
}

.correct[data-item="css"]::before,
.flipped[data-item="css"]::before {
  content: "🎨";
}