html {
  padding: 0;
  margin: 0;
  box-sizing: border-box;
}

.container {
  display: flex;
  justify-content: center;
  flex-direction: column;
  align-items: center;
  height: 100vh;
  background: rgb(221, 220, 220);
}

.stop-watch {
  margin-bottom: 10px;
  font-size: 70px;
}

.stop-watch span {
  display: inline;
  margin: 0;
  padding: 0;
}

.btn {
  display: inline-block;
  color: white;
  padding: 10px;
  cursor: pointer;
  display: inline-block;
  cursor: pointer;
  color: #ffffff;
  font-family: Arial;
  font-size: 20px;
  padding: 6px 24px;
  border-radius: 3px;
}

.stop {
  box-shadow: inset 0px 1px 0px 0px #cf866c;
  background: linear-gradient(to bottom, #d0451b 5%, #bc3315 100%);
  border: 1px solid #942911;
}

.stop:hover {
  background: linear-gradient(to bottom, #bc3315 5%, #d0451b 100%);
  background-color: #bc3315;
}

.start {
  box-shadow: inset 0px 1px 0px 0px #3dc21b;
  background: linear-gradient(to bottom, #228f3f 5%, #5cbf2a 100%);
  border: 1px solid #18ab29;
}
.start:hover {
  background: linear-gradient(to bottom, #5cbf2a 5%, #228f3f 100%);
  background-color: #5cbf2a;
}

.reset {
  box-shadow: inset 0px 1px 0px 0px #c3db11;
  background: linear-gradient(to bottom, #815a0c 5%, #dede16 100%);
  border: 1px solid #adad23;
}
.reset:hover {
  background: linear-gradient(to bottom, #dede16 5%, #d4961b 100%);
  background-color: #dede16;
}