main.css

* {
  box-sizing: border-box;
}

:root {
  --green: #009f77;
  --blue: #200a74;
}

html,
body {
  height: 100vh;
}

header {
  padding: 1em;
}
main {
  padding: 1em;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, sans-serif;
  margin: 0;
  font-size: 1.3rem;
  color: #444444;
  display: flex;
  flex-direction: column;
}

header {
  width: 100%;
  color: var(--blue);
}

h1 {
  text-align: center;
  margin: 0;
}
.tagline {
  text-align: center;
  margin-top: 0;
  border-bottom: 1px solid var(--green);
  padding-bottom: 0.5em;
}

.flex-container {
  display: flex;
  justify-content: space-between;
}

main {
  width: 100%;
}

.seediv {
  display: flex;
  align-items: center;
}

.seediv img {
  width: 24px;
}

.seediv label {
  font-size: 1.2em;
}

#seed {
  height: 48px;
  margin: 0 0.5em;
  font-size: 1.2em;
}

.controls {
  display: flex;
}

.controls > button {
  margin: 0 0.5em;
  height: 48px;
}

.howto {
  display: flex;
  align-items: center;
  font-size: 0.8em;
}

.howto a,
.howto a:visited,
.howto a:hover {
  color: var(--blue);
  font-size: 1.2em;
}
button {
  background: white;
  transition: background 0.2s ease;
  border-radius: 2px;
  font-size: 1rem;
  padding: 0.5rem 1rem;
}

button:hover {
  background: var(--green);
  cursor: pointer;
  color: white;
}

canvas {
  border: 5px solid var(--green);
  margin: 2em 0 0 0;
  width: 100%;
}

.guess_controls {
  width: 100%;
  text-align: center;
  margin-bottom: 1em;
}

.slider {
  -webkit-appearance: none; /* Override default CSS styles */
  appearance: none;
  width: 100%; /* Full-width */
  height: 50px; /* Specified height */
  background: white;
  border: 5px solid var(--green);
  outline: none; /* Remove outline */
  opacity: 0.7; /* Set transparency (for mouse-over effects on hover) */
  -webkit-transition: 0.2s; /* 0.2 seconds transition on hover */
  transition: opacity 0.2s;
}

/* Mouse-over effects */
.slider:hover {
  opacity: 1; /* Fully shown on mouse-over */
}

/* The slider handle (use -webkit- (Chrome, Opera, Safari, Edge) and -moz- (Firefox) to override default look) */
.slider::-webkit-slider-thumb {
  -webkit-appearance: none; /* Override default look */
  appearance: none;
  width: 10px; /* Set a specific slider handle width */
  height: 50px; /* Slider handle height */
  background: black; /* Green background */
  cursor: pointer; /* Cursor on hover */
}

.slider::-moz-range-thumb {
  width: 10x; /* Set a specific slider handle width */
  height: 50px; /* Slider handle height */
  background: black; /* Green background */
  cursor: pointer; /* Cursor on hover */
}

.white-text {
  color: white;
}

#card {
  width: 50%;
  display: flex;
  text-align: center;
  margin: auto;
  color: white;
}

#card > div {
  width: 50%;
  padding: 1em;
  font-size: 1.5em;
}

.left-card {
  background: var(--green);
}

.right-card {
  background: var(--blue);
}

.scoreboard {
  width: 50%;
  margin: auto;
  display: flex;
  margin-top: 2em;
}

.scoreboard > div {
  width: 50%;
  text-align: center;
}

.score-controls {
  width: 80%;
  margin: auto;
  font-size: 2em;
  display: flex;
  justify-content: center;
  margin-top: 0.5em;
}

.score-controls input[type="number"] {
  width: 50px;
  text-align: center;
  border-radius: 10px;
  font-size: 32px;
  font-style: bold;
  -moz-appearance: textfield;
  border: 1px #dddddd solid;
  margin: 0 0.5em;
}

.score {
  text-align: center;
  font-size: 2em;
}

footer {
  background: var(--blue);
  color: white;
  margin: 2em 0 0 0;
  padding: 1em;
  display: flex;
  justify-content: space-evenly;
}

footer a,
footer a:visited,
footer a:hover {
  color: white;
}

span[contenteditable]::after {
  content: "✏️";
  font-size: 0.8em;
  padding-left: 1em;
}