* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}
.container {
  max-width: 600px;
  width: 100%;
  height: 400px;
  margin: 0 auto;
  font-size: 18px;
  text-align: center;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
}
.countDown {
  width: 100%;
}
.countDown.hide {
  display: none;
}
.count {
  font-size: 2.4em;
  margin-bottom: 30px;
}
.countBtn {
  display: inline-block;
  width: 180px;
  height: 180px;
  margin: 0 auto;
  border-radius: 50%;
  font-size: 2.4em;
  color: #ffffff;
  background-color: #ff0000;
  box-shadow: 1px 10px #800000;
  cursor: pointer;
}
.countBtn:active {
  box-shadow: 1px 5px #800000;
  position: relative;
  top: 5px;
}
.endScreen {
  width: 100%;
}
.endScreen.hide {
  display: none;
}
.endMsg {
  margin-bottom: 30px;
  font-size: 1.8em;
}
.resetBtn {
  width: 60%;
  margin: 0 auto;
  padding: 10px;
  font-size: 1.2em;
  cursor: pointer;
  background-color: #008000;
  color: #fff;
  border: none;
  border-radius: 5px;
}
.resetBtn:hover {
  background-color: #006400;
}