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

html {
  font-size: 1.2em;
}

body {
  align-items: center;
  background: #343434;
  color: #fefefe;
  display: flex;
  font-family: Helvetica, Arial, sans-serif;
  justify-content: center;
  line-height: 140%;
  min-height: 100vh;
  max-width: 700px;
  margin: 0 auto;
}

main {
  font-size: 2rem;
  display: flex;
  flex-direction: column;
  align-items: center;
}

button {
  width: 100%;
  padding: 10px 0px;
  font-size: 20px;
  border-radius: 5px;
  border: 2px solid black;
  margin: 10px;
  cursor: pointer;
}

button:hover {
  background-color: lightgray;
}

p {
  font-size: 1rem;
}

.choice-button {
  display: none;
}

.timer {
  color: red;
  font-size: 2rem;
}