.but,
button {
  outline: none;
  border: none;
  background: inherit;
  box-sizing: border-box !important;
}

.button-1 {
  background-color: #3498db;
  color: #fff;
  border: none;
  padding: 15px 30px;
  border-radius: 5px;
  font-size: 18px;
  cursor: pointer;
  transition: background-color 0.3s, transform 0.2s;
}

.button-1:hover {
  color: #fff;
  background-color: #2680c2;
  transform: scale(1.05);
}

.button-2 {
  position: relative;
  display: inline-block;
  padding: 15px 30px;
  text-align: center;
  font-size: 14px;
  letter-spacing: 1px;
  text-decoration: none;
  color: #725ac1;
  background: transparent;
  cursor: pointer;
  transition: ease-out 0.5s;
  border: 2px solid #725ac1;
  border-radius: 10px;
  box-shadow: inset 0 0 0 0 #725ac1;
}

.button-2:hover {
  color: white;
  box-shadow: inset 0 -100px 0 0 #725ac1;
}

.button-2:active {
  transform: scale(0.9);
}

.button-3 {
  padding: 15px 25px;
  border: unset;
  border-radius: 15px;
  color: #212121;
  z-index: 1;
  background: #e8e8e8;
  position: relative;
  font-weight: 1000;
  font-size: 17px;
  -webkit-box-shadow: 4px 8px 19px -3px rgba(0, 0, 0, 0.27);
  box-shadow: 4px 8px 19px -3px rgba(0, 0, 0, 0.27);
  transition: all 250ms;
  overflow: hidden;
}

.button-3::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  height: 100%;
  width: 0;
  border-radius: 15px;
  background-color: #212121;
  z-index: -1;
  -webkit-box-shadow: 4px 8px 19px -3px rgba(0, 0, 0, 0.27);
  box-shadow: 4px 8px 19px -3px rgba(0, 0, 0, 0.27);
  transition: all 250ms;
}

.button-3:hover {
  color: #e8e8e8;
}

.button-3:hover::before {
  width: 100%;
}

.button-4 {
  background-color: #e74c3c;
  color: #fff;
  border: none;
  padding: 15px 30px;
  border-radius: 5px;
  font-size: 18px;
  cursor: pointer;
  transition: background-color 0.3s, transform 0.2s;
}

.button-4:hover {
  color: #fff;
  background-color: #c73a2d;
  transform: scale(1.05);
}

.button-5 {
  font-size: 17px;
  padding: 0.5em 2em;
  border: transparent;
  box-shadow: 2px 2px 4px rgba(0, 0, 0, 0.4);
  background: dodgerblue;
  color: white;
  border-radius: 4px;
}

.button-5:hover {
  background: rgb(2, 0, 36);
  background: linear-gradient(90deg, rgba(30, 144, 255, 1) 0%, rgba(0, 212, 255, 1) 100%);
}

.button-5:active {
  transform: translate(0em, 0.2em);
}