style.css

body {
  padding: 0px;
  margin: 0px;

  background: linear-gradient(
    0deg,
    rgb(193, 202, 212) 0%,
    rgba(234, 229, 253, 0) 25%
  );
  height: 100vh;
}

h1 {
  margin-top: 0px;
  margin-bottom: 5px;
  font-size: 3.5em;
}

.center {
  text-align: center;
}

.controller-status {
  font-weight: bold;
  text-align: center;
}

#controller-connected {
  color: green;
}

#controller-connected-area {
  display: none;
}

#controller-not-connected-area {
  color: darkred;
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 10px;
}

#rumble-on-button-press-area {
  margin-bottom: 10px;
  text-align: center;
}

.loader {
  display: inline-block;
  border: 8px solid #484848;
  border-radius: 50%;
  border-top: 8px solid #3498db;
  border-bottom: 8px solid #3498db;
  width: 20px;
  height: 20px;
  -webkit-animation: spin 1.5s linear infinite;
  animation: spin 1.5s linear infinite;
}
@keyframes spin {
  0% {
    transform: rotate(0deg);
  }
  100% {
    transform: rotate(360deg);
  }
}

/* button grid */
#buttons {
  display: grid;
  grid-template-columns: repeat(8, minmax(min-content, max-content));
  grid-gap: 15px;
  justify-content: center;
  justify-items: start;
}

.button {
  background-color: rgb(223, 222, 222);
  height: 50px;
  min-width: 50px;
  display: flex;
}

.button-text-area {
  padding-left: 10px;
  padding-right: 10px;
}

.button-name {
  color: grey;
}

/* controller */

.selected-button {
  fill: rgb(231, 24, 24);
}

/* axes */

.axis-name {
  color: grey;
  font-weight: bolder;
}

.axis-value {
  color: rgb(126, 54, 54);
}

a {
  color: red;
}