index.css

body {
  width: 100vw;
  min-width: 320px;
}

#root {
  padding: 40px 20px;
  max-width: 600px;
  margin: auto;
  height: 100vh;

  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

#root > * + * {
  margin: 20px 0 0 0;
}

/* 100vh on safari does not include the bottom bar. */
@supports (-webkit-overflow-scrolling: touch) {
  #root {
    height: 85vh;
  }
}

#message-log {
  width: 100%;
  flex-grow: 1;
  overflow: auto;
}

#message-log p:first-child {
  margin: 0;
}

#message-log > * + * {
  margin: 10px 0 0 0;
}

#publish-form-container {
  width: 100%;
}

#publish-form {
  width: 100%;
  display: flex;
  height: 40px;
}

#publish-form > * + * {
  margin: 0 0 0 10px;
}

#publish-form input[type='text'] {
  flex-grow: 1;

  -moz-appearance: none;
  -webkit-appearance: none;
  word-break: normal;
  border-radius: 5px;
  border: 1px solid #ccc;
}

#publish-form input[type='submit'] {
  color: white;
  background-color: black;
  border-radius: 5px;
  padding: 5px 10px;
  border: none;
}

#publish-form input[type='submit']:hover {
  background-color: red;
}

#publish-form input[type='submit']:active {
  background-color: red;
}