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

:root {
  --bg_body: #212121;
  --bg_gradient_last_color: rgba(0, 212, 255, 1);
  --bg_gradient: linear-gradient(90deg,
      rgba(2, 0, 36, 1) 0%,
      rgba(52, 9, 121, 1) 37%,
      var(--bg_gradient_last_color) 94%);
}

body {
  background-color: var(--bg_body);
  color: #fff;
  font-family: monospace, serif;
  letter-spacing: 0.05em;
}

h1 {
  font-size: 23px;
}

.form {
  width: 300px;
  padding: 64px 15px 24px;
  margin: 0 auto;
}

.form .control {
  margin: 0 0 24px;
  text-align: center;
}

.form .control .h1 {
  margin: 0 0 24px;
  text-align: center;
  text-shadow: #212121 0px 0px 10px;
}

.form .control input {
  width: 100%;
  padding: 14px 16px;
  border: 0;
  background: transparent;
  color: #fff;
  font-family: monospace, serif;
  letter-spacing: 0.05em;
  font-size: 16px;
}

.form .control input:hover,
.form .control input:focus {
  outline: none;
  border: 0;
}

.form .btn {
  width: 100%;
  display: block;
  padding: 14px 16px;
  background: transparent;
  outline: none;
  border: 0;
  color: #fff;
  letter-spacing: 0.1em;
  font-weight: bold;
  font-family: monospace;
  font-size: 16px;
}

.block-cube {
  position: relative;
}

.block-cube .bg-top {
  position: absolute;
  height: 10px;
  background: rgb(2, 0, 36);
  background: var(--bg_gradient);
  bottom: 100%;
  left: 5px;
  right: -5px;
  transform: skew(-45deg, 0);
  margin: 0;
}

.block-cube .bg-top .bg-inner {
  bottom: 0;
}

.block-cube .bg {
  position: absolute;
  left: 0;
  top: 0;
  right: 0;
  bottom: 0;
  background: rgb(2, 0, 36);
  background: var(--bg_gradient);
}

.block-cube .bg-right {
  position: absolute;
  background: rgb(2, 0, 36);
  background: rgba(0, 212, 255, 1);
  top: -5px;
  z-index: 0;
  bottom: 5px;
  width: 10px;
  left: 100%;
  transform: skew(0, -45deg);
}

.block-cube .bg-right .bg-inner {
  left: 0;
}

.block-cube .bg .bg-inner {
  transition: all 0.2s ease-in-out;
}

.block-cube .bg-inner {
  background: var(--bg_body);
  position: absolute;
  left: 2px;
  top: 2px;
  right: 2px;
  bottom: 2px;
}

.block-cube .text {
  position: relative;
  z-index: 2;
}

.block-cube.block-input input {
  position: relative;
  z-index: 2;
}

.block-cube.block-input input:focus~.bg-right .bg-inner,
.block-cube.block-input input:focus~.bg-top .bg-inner,
.block-cube.block-input input:focus~.bg-inner .bg-inner {
  top: 100%;
  background: rgba(255, 255, 255, 0.5);
}

.block-cube.block-input .bg-top,
.block-cube.block-input .bg-right,
.block-cube.block-input .bg {
  background: rgba(255, 255, 255, 0.5);
  transition: background 0.2s ease-in-out;
}

.block-cube.block-input .bg-right .bg-inner,
.block-cube.block-input .bg-top .bg-inner {
  transition: all 0.2s ease-in-out;
}

.block-cube.block-input:hover .bg-top,
.block-cube.block-input:hover .bg-right,
.block-cube.block-input:hover .bg {
  background: rgba(255, 255, 255, 0.8);
}

.block-cube-hover:focus .bg .bg-inner,
.block-cube-hover:hover .bg .bg-inner {
  top: 100%;
}

.credits {
  position: fixed;
  left: 0;
  bottom: 0;
  padding: 15px 15px;
  width: 100%;
  z-index: 111;
}

.credits a {
  opacity: 0.6;
  color: #fff;
  font-size: 11px;
  text-decoration: none;
}

.credits a:hover {
  opacity: 1;
}