h1, h2 {
  color: black;
}

.center {
text-align: center;
}

* {box-sizing: border-box}

/* Set height of body and the document to 100% */
body, html {
  height: 100%;
  margin: 0;
  font-family: Arial;
}

/* Style tab links */
.tablink {
   background-color: #555;
   color: white;
   float: left;
   border: none;
   outline: none;
   cursor: pointer;
   padding: 14px 16px;
   font-size: 17px;
   width: 25%;
   text-align: center;
   text-decoration: none;
 }

.tablink:hover {
  background-color: #777;
}

.tabcontent {
  color: white;
  display: none;
  padding: 100px 20px;
  padding-bottom: 0px;
}

#stopwatch {
  padding-top: 50px;
}

#stopwatch {
  margin-left: auto;
  margin-right: auto;
  text-align: center;
  padding-left: 0px;
  border-radius: 10px;
  max-width: 100%;
  padding-top: 10px;
}

#sw-time {
  font-size: 96px;
  font-weight: bold;
  text-align: center;
}

#sw-rst, #sw-go {
  width: 45%;
  box-sizing: padding-box;
  padding: 10px;
  display: inline-block;
  background: #aa2f2f;
  border: 0;
  color: white;
  font-size: 26.66666px;
}

.dbl {
  font-size: 4em;
}

.mt-0 {
  margin-top: 0px;
}

.mb-0 {
  margin-bottom: 0px;
}

.tc:hover {
  background-color: red;
}

.ta:hover {
  background-color: blue;
}

.tt:hover {
  background-color: green;
}

.ts:hover {
  background-color: orange;
}