<a class="button plus" href="#plus">
  <span class="bg" id="plus"></span>
  <span class="symbol"></span>
</a>
<a class="button minus" href="#minus">
  <span class="bg" id="minus"></span>
  <span class="symbol"></span>
</a>
<span class="cancel">
  <a href="#">Clear</a>
</span>

html, body {
  height: 100%;
  margin: 0;
}
body {
  display: flex;
  justify-content: center;
  align-items: center;
  align-content: center;
  flex-wrap: wrap;
  background-color: #56b3a3;
}
a {
  text-decoration: none;
}
a::-moz-focus-inner {
  border: 0;
}
.button {
  position: relative;
  width: 5.5rem;
  height: 5.5rem;
  margin: 1rem;
  border-radius: 50%;
}
.button > span {
  position: absolute;
  display: block;
  width: 100%;
  height: 100%;
}
.bg {
  border-radius: 50%;
  background-color: rgba(255, 255, 255, 0.2);
  box-shadow: 0 2px 3px rgba(0, 0, 0, 0.1);
  transition: all 0.2s linear;
}
.cancel {
  flex: 1 1 100%;
  margin-top: 1rem;
  text-align: center;
}
.cancel a {
  display: inline-block;
  padding: 0.5rem;
  border-radius: 5px;
  color: #fff;
  font-family: monospace;
  text-transform: uppercase;
  letter-spacing: 2px;
  line-height: 1.4;
  transition: background-color 0.1s linear;
}
.cancel a:hover {
  background-color: rgba(255, 255, 255, 0.1);
}
.cancel a:active {
  background-color: rgba(255, 255, 255, 0.2);
}
.symbol::before, .symbol::after {
  position: absolute;
  top: 0;
  bottom: 0;
  right: 0;
  left: 0;
  display: block;
  margin: auto;
  border-radius: 2px;
  content: "";
}
.symbol::before{
  width: 2rem;
  height: 0.3rem;
  background-color: #515676;
  transition: background-color 1s linear;
}
.plus .symbol::after {
  width: 0.3rem;
  height: 2rem;
  background-color: #515676;
}
.bg::before, .bg::after {
  position: absolute;
  top: -4.75rem;
  left: -4.75rem;
  display: block;
  width: 15rem;
  height: 15rem;
  border: 4px solid #fff;
  border-radius: 50%;
  box-sizing: border-box;
  content: "";
  transform: scale(0.4);
  opacity: 0;
}
.button:hover .bg {
  background-color: rgba(255, 255, 255, 0.3)
}
.bg:target {
  animation: push 1s ease-out;
  transition: all 1s linear;
}
#plus:target {
  background-color: #def186;
}
#minus:target {
  background-color: #515676;
}
#minus:target + .symbol::before {
  background-color: #def186;
}
.bg:target::before, .bg:target::after {
  animation: wave 1s ease-in-out;
}
.bg:target::before {
  animation-delay: 0.2s;
}
.bg:target::after {
  animation-delay: 0.3s;
}

@keyframes push {
  15% {transform: scale(0.75); box-shadow: 0 0 1px rgba(0, 0, 0, 0.3)}
  75% {transform: scale(1.1); box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1)}
  100% {transform: scale(1)}
}

@keyframes wave {
  10% {opacity: 0.3}
  100% {transform: scale(1); opacity: 0}
}