:root {
  --canvas: #fff;
  --canvastext: #000;
  --compose-height: 50px;

  color-scheme: dark light;
}

@media (prefers-color-scheme: dark) {
  :root {
    --canvas: #000;
    --canvastext: #fff;
  }
}

html {
  box-sizing: border-box;
  height: var(--100vh, 100vh);
}

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

body {
  padding: 1rem;
  font-family: system-ui, sans-serif;
  height: 100%;
  overflow: hidden;
}


.container {
  height: 100%;
  display: grid;
  gap: 10px 10px;
  grid-template:    
    "messages" 1fr
    "compose" var(--compose-height)
    "keyboard" env(keyboard-inset-height, 0px);
}

.messages {
  overflow-y: auto;
  overflow-x: hidden;
  display: flex;  
  justify-content: center;  
  height: 100%;
}

.compose {
  border: solid 1px var(--canvastext);
  width: 100%;
  height: var(--compose-height);
}


ul {
  margin-inline-start: 0;
  margin-block-start: auto;
  list-style: none;  
  padding: 10px;
}

li {
  padding: 0.25rem;
  color: var(--canvas);
  margin-block-end: 0.25rem;
  border-radius: 0.25rem;
  position: relative;
  word-break: break-word;
}

input {
  flex-grow: 1;
  font-size: inherit;
  border-radius: 0;
}

button {
  appearance: none;
  background-color: var(--canvastext);
  color: var(--canvas);
  border: none;
}

input:focus-visible,
button:focus-visible {
  outline: none;
}

form {
  display: flex;
  height: 100%;
}

.me {
  background-color: deeppink;
  margin-inline-end: 1rem;
}

.me::before,
.them::before {
  content: "";
  position: absolute;
  width: 10px;
  height: 10px;
}

.me::before {
  left: -10px;
  border-style: solid;
  border-width: 10px 15px 10px 0;
  border-color: transparent deeppink transparent transparent;
}

.them {
  background-color: turquoise;
  margin-inline-start: 1rem;
}

.them::before {
  right: -10px;
  border-style: solid;
  border-width: 10px 0 10px 15px;
  border-color: transparent transparent transparent turquoise;
}