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

html {
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu, Cantarell, "Open Sans", "Helvetica Neue", sans-serif;
  --font-title: Georgia, "Times New Roman", Times, serif;
  --font-size: 1.2rem;
  --color: #19f;
  --color-light: #adf;
  --color-dark: #018;
  --radius: 0.2rem;
}

body {
  margin: 0;
}

body,
input,
textarea,
button {
  font-size: var(--font-size);
  font-family: var(--font);
}

h1,
h2,
h3 {
  font-family: var(--font-title);
}

h1,
h2,
h3,
p,
ul {
  margin: 1rem 0;
}

ul {
  list-style: square;
}

li {
  margin-bottom: 0.5rem;
}

label {
  display: block;
  margin-bottom: 0.25rem;
}

input[type="text"],
input[type="password"],
input[type="email"],
textarea {
  display: block;
  border: 1px solid #ccc;
  width: 100%;
  padding: 0.8rem;
  border-radius: var(--radius);
  background: #eee;
  transition: 0.2s;
  margin-bottom: 1rem;
}

input[type="text"]:focus,
input[type="password"]:focus,
input[type="email"]:focus,
textarea:focus {
  outline: none;
  border-color: var(--color);
  background: white;
  box-shadow: 0 0 0 3px var(--color-light);
}

button {
  cursor: pointer;
  border: none;
  border-radius: var(--radius);
  transition: 0.1s;
  background: var(--color);
  color: var(--color-dark);
  padding: 0.8rem 1.6rem;
}

button:hover,
button:focus {
  background: var(--color);
  box-shadow: 0 0 0 3px var(--color-light), 0 0 0 4px var(--color);
  outline: none;
}

button:active {
  box-shadow: 0 0 0 3px var(--color), 0 0 0 4px var(--color);
}

button:disabled {
  opacity: 0.5;
  cursor: wait;
}

hr {
  border: 2px solid black;
  margin: 2rem auto;
}