demo.css

* {
  box-sizing: border-box;
  -webkit-tap-highlight-color: transparent;
}

*:focus {
  outline: none;
}

[data-focus-visible] *:focus {
  box-shadow: 0 0 0px 4px rgba(64, 167, 255, 0.6);
  border-color: rgb(64, 167, 255);
  outline: none;
}

body {
  margin: 8px;
  font-family: sans-serif;
  font-size: 14px;
  color: #333;
}

.form {
  max-width: 600px;
}

.form-group {
  margin-bottom: 20px;
}

.form-control {
  display: block;
  width: 100%;
  height: 32px;
  padding: 4px 8px;
  font-size: 14px;
  line-height: 22px;
  color: #333;
  background-clip: padding-box;
  background-color: #fff;
  background-image: none;
  border: 1px solid #ccc;
  border-radius: 4px;
}

input.form-control[type="text"]:focus,
textarea:focus {
  box-shadow: 0 0 0px 4px rgba(64, 167, 255, 0.6);
  border-color: rgb(64, 167, 255);
}

textarea.form-control {
  height: auto;
}

[data-focus-visible] .radio:focus,
[data-focus-visible] .checkbox:focus {
  outline: 4px solid rgba(64, 167, 255, 0.6);
}

.button {
  border: 1px solid #999;
  border-radius: 4px;
  background-color: #fff;
  height: 32px;
  padding: 4px 8px;
  font-size: 14px;
  line-height: 22px;
  color: #333;
}

.button::-moz-focus-inner {
  border-style: none;
  padding: 0;
}

.button:active {
  background-color: #ddd;
}