public/stylesheets/style.css

header [role="progressbar"][aria-busy="true"] {
  position: absolute;
  top: 0;
  left: 0;
  padding-top: 8px;
  width: 100%;
  background-color: #159756;
  -webkit-animation: preloader-background linear 3.5s infinite;
          animation: preloader-background linear 3.5s infinite;
}
header [role="progressbar"][aria-busy="true"]::before, header [role="progressbar"][aria-busy="true"]::after {
  display: block;
  position: absolute;
  top: 0;
  z-index: 2;
  width: 0;
  height: 8px;
  background: #afa;
  -webkit-animation: preloader-front linear 3.5s infinite;
          animation: preloader-front linear 3.5s infinite;
  content: '';
}
header [role="progressbar"][aria-busy="true"]::before {
  right: 50%;
}
header [role="progressbar"][aria-busy="true"]::after {
  left: 50%;
}

@-webkit-keyframes preloader-background {
  0%, 24.9% {
    background-color: #159756;
  }
  25%, 49.9% {
    background-color: #da4733;
  }
  50%, 74.9% {
    background-color: #3b78e7;
  }
  75%, 100% {
    background-color: #fdba2c;
  }
}

@keyframes preloader-background {
  0%, 24.9% {
    background-color: #159756;
  }
  25%, 49.9% {
    background-color: #da4733;
  }
  50%, 74.9% {
    background-color: #3b78e7;
  }
  75%, 100% {
    background-color: #fdba2c;
  }
}
@-webkit-keyframes preloader-front {
  0% {
    width: 0;
    background-color: #da4733;
  }
  24.9% {
    width: 50%;
    background-color: #da4733;
  }
  25% {
    width: 0;
    background-color: #3b78e7;
  }
  49.9% {
    width: 50%;
    background-color: #3b78e7;
  }
  50% {
    width: 0;
    background-color: #fdba2c;
  }
  74.9% {
    width: 50%;
    background-color: #fdba2c;
  }
  75% {
    width: 0%;
    background-color: #159756;
  }
  100% {
    width: 50%;
    background-color: #159756;
  }
}
@keyframes preloader-front {
  0% {
    width: 0;
    background-color: #da4733;
  }
  24.9% {
    width: 50%;
    background-color: #da4733;
  }
  25% {
    width: 0;
    background-color: #3b78e7;
  }
  49.9% {
    width: 50%;
    background-color: #3b78e7;
  }
  50% {
    width: 0;
    background-color: #fdba2c;
  }
  74.9% {
    width: 50%;
    background-color: #fdba2c;
  }
  75% {
    width: 0%;
    background-color: #159756;
  }
  100% {
    width: 50%;
    background-color: #159756;
  }
}
* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  height: 100%;
}

body {
  display: flex;
  flex-direction: column;
  align-items: center;
  font-family: Avenir Next, Helvetica Neue, Helvetica, Arial, sans-serif;
  background-color: #f5f5f5;
}

header {
  position: relative;
  width: 100%;
  height: 60px;
  box-shadow: 0 2px 2px rgba(0, 0, 0, 0.2);
  background-color: #fff;
}

main {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 20px;
  flex-grow: 1;
  text-align: center;
}
:root main > * + * {
  margin-top: 1em;
}

h1 {
  margin: 0;
  font-size: 2.2em;
  font-weight: 200;
}

p {
  margin: 0;
  font-size: .875em;
  font-weight: 400;
}

.log{
  max-width: 100%;
text-align: center;
}