html {
  box-sizing: border-box;
}

*, *:before, *:after {
  box-sizing: inherit;
}

html, body, #root {
  height: 100%;
}

body {
  padding: 1rem;
  font-family: Sylfaen, 'American Typewriter', 'Bookman Old Style', sans-serif;
  background-color: #F7F7F7;
}

.main {
  width: 50%;
  margin: auto;
  padding: 0.3rem;
  background-color: white;
  border: 0.2rem solid #ECECEC;
  border-radius: 0.3rem;
}

.tab-content {
  margin: 0.2rem;
  padding: 0.5rem 0.8rem 0.3rem 0.8rem;
}

.game-panel {
  border: transparent gray;
  border-radius: 0.25rem;
  text-align: center;
}

.game-panel .badge {
  font-family: Tahoma, Verdana, sans-serif;
}

.label {
  margin-bottom: 0.5rem;
}

.alert {
  /* override Bootstrap's setting */
  margin-bottom: 0.5rem;
}

a.nav-link {
  color: gray;
}

.instant-result {
  padding: 0.2rem 0.5rem 0rem 0.5rem;
  font-size: 2rem;
  margin-top: 0.8rem;
}

.button-container {
  margin: 0.5rem;
}

.n-back-card {
  font-size: 5rem;
  padding: 0.5rem 1rem;
  margin-top: 1rem;
}

.cmd-btn {
  font-size: 1.3rem;
  margin: 0.5rem;
  text-transform: uppercase;
}

/* Mobile */

@media (orientation: portrait) and (max-device-width: 1200px) {
  html {
    font-size: 5vmin;
  }

  body {
    padding: 0.5rem;
  }

  .main {
    width: 100%;
  }

  .cmd-btn {
    display: block;
    font-size: 1.4rem;
    width: 70%;
    margin: 0rem auto 1rem auto;
  }
}

/* Animation */

.fade-enter .btn {
  opacity: 0.2;
  transform: translateX(150%);
}
.fade-enter-active .btn {
  opacity: 1;
  transform: translateX(0%);
}
.fade-exit .btn {
  opacity: 1;
  transform: translateX(0%);
}
.fade-exit-active .btn {
  opacity: 0;
  transform: translateX(-150%);
}
.fade-enter-active .btn {
  transition: opacity 300ms, transform 300ms;
}
.fade-exit-active .btn {
  transition: opacity 400ms, transform 400ms;
}