CSS Candy Color Button Animation

body {
  background: #e0e5ec;
}
h1 {
  position: relative;
  text-align: center;
  color: #353535;
  font-size: 50px;
  font-family: "Cormorant Garamond", serif;
}

p {
  font-family: 'Lato', sans-serif;
  font-weight: 300;
  text-align: center;
  font-size: 18px;
  color: #676767;
}
.frame {
  width: 90%;
  margin: 40px auto;
  text-align: center;
}
button {
  margin: 20px;
}
.custom-btn {
  width: 130px;
  height: 40px;
  color: #fff;
  border-radius: 5px;
  padding: 10px 25px;
  font-family: 'Lato', sans-serif;
  font-weight: 500;
  background: transparent;
  cursor: pointer;
  transition: all 0.3s ease;
  position: relative;
  display: inline-block;
   box-shadow:inset 2px 2px 2px 0px rgba(255,255,255,.5),
   7px 7px 20px 0px rgba(0,0,0,.1),
   4px 4px 5px 0px rgba(0,0,0,.1);
  outline: none;
}

/* 1 */
.btn-1 {
  background: rgb(6,14,131);
  background: linear-gradient(0deg, rgba(6,14,131,1) 0%, rgba(12,25,180,1) 100%);
  border: none;
}
.btn-1:hover {
   background: rgb(0,3,255);
background: linear-gradient(0deg, rgba(0,3,255,1) 0%, rgba(2,126,251,1) 100%);
}

/* 2 */
.btn-2 {
  background: rgb(96,9,240);
  background: linear-gradient(0deg, rgba(96,9,240,1) 0%, rgba(129,5,240,1) 100%);
  border: none;
 
}
.btn-2:before {
  height: 0%;
  width: 2px;
}
.btn-2:hover {
  box-shadow:  4px 4px 6px 0 rgba(255,255,255,.5),
              -4px -4px 6px 0 rgba(116, 125, 136, .5),
    inset -4px -4px 6px 0 rgba(255,255,255,.2),
    inset 4px 4px 6px 0 rgba(0, 0, 0, .4);
}


/* 3 */
.btn-3 {
  background: rgb(0,172,238);
background: linear-gradient(0deg, rgba(0,172,238,1) 0%, rgba(2,126,251,1) 100%);
  width: 130px;
  height: 40px;
  line-height: 42px;
  padding: 0;
  border: none;
 
}
.btn-3 span {
  position: relative;
  display: block;
  width: 100%;
  height: 100%;
}
.btn-3:before,
.btn-3:after {
  position: absolute;
  content: "";
  right: 0;
  top: 0;
   background: rgba(2,126,251,1);
  transition: all 0.3s ease;
}
.btn-3:before {
  height: 0%;
  width: 2px;
}
.btn-3:after {
  width: 0%;
  height: 2px;
}
.btn-3:hover{
   background: transparent;
  box-shadow: none;
}
.btn-3:hover:before {
  height: 100%;
}
.btn-3:hover:after {
  width: 100%;
}
.btn-3 span:hover{
   color: rgba(2,126,251,1);
}
.btn-3 span:before,
.btn-3 span:after {
  position: absolute;
  content: "";
  left: 0;
  bottom: 0;
   background: rgba(2,126,251,1);
  transition: all 0.3s ease;
}
.btn-3 span:before {
  width: 2px;
  height: 0%;
}
.btn-3 span:after {
  width: 0%;
  height: 2px;
}
.btn-3 span:hover:before {
  height: 100%;
}
.btn-3 span:hover:after {
  width: 100%;
}

/* 4 */
.btn-4 {
  background-color: #4dccc6;
background-image: linear-gradient(315deg, #4dccc6 0%, #96e4df 74%);
  line-height: 42px;
  padding: 0;
  border: none;
}
.btn-4:hover{
  background-color: #89d8d3;
background-image: linear-gradient(315deg, #89d8d3 0%, #03c8a8 74%);
}
.btn-4 span {
  position: relative;
  display: block;
  width: 100%;
  height: 100%;
}
.btn-4:before,
.btn-4:after {
  position: absolute;
  content: "";
  right: 0;
  top: 0;
   box-shadow:  4px 4px 6px 0 rgba(255,255,255,.9),
              -4px -4px 6px 0 rgba(116, 125, 136, .2),
    inset -4px -4px 6px 0 rgba(255,255,255,.9),
    inset 4px 4px 6px 0 rgba(116, 125, 136, .3);
  transition: all 0.3s ease;
}
.btn-4:before {
  height: 0%;
  width: .1px;
}
.btn-4:after {
  width: 0%;
  height: .1px;
}
.btn-4:hover:before {
  height: 100%;
}
.btn-4:hover:after {
  width: 100%;
}
.btn-4 span:before,
.btn-4 span:after {
  position: absolute;
  content: "";
  left: 0;
  bottom: 0;
  box-shadow:  4px 4px 6px 0 rgba(255,255,255,.9),
              -4px -4px 6px 0 rgba(116, 125, 136, .2),
    inset -4px -4px 6px 0 rgba(255,255,255,.9),
    inset 4px 4px 6px 0 rgba(116, 125, 136, .3);
  transition: all 0.3s ease;
}
.btn-4 span:before {
  width: .1px;
  height: 0%;
}
.btn-4 span:after {
  width: 0%;
  height: .1px;
}
.btn-4 span:hover:before {
  height: 100%;
}
.btn-4 span:hover:after {
  width: 100%;
}

/* 5 */
.btn-5 {
  width: 130px;
  height: 40px;
  line-height: 42px;
  padding: 0;
  border: none;
  background: rgb(255,27,0);
background: linear-gradient(0deg, rgba(255,27,0,1) 0%, rgba(251,75,2,1) 100%);
}
.btn-5:hover {
  color: #f0094a;
  background: transparent;
   box-shadow:none;
}
.btn-5:before,
.btn-5:after{
  content:'';
  position:absolute;
  top:0;
  right:0;
  height:2px;
  width:0;
  background: #f0094a;
  box-shadow:
   -1px -1px 5px 0px #fff,
   7px 7px 20px 0px #0003,
   4px 4px 5px 0px #0002;
  transition:400ms ease all;
}
.btn-5:after{
  right:inherit;
  top:inherit;
  left:0;
  bottom:0;
}
.btn-5:hover:before,
.btn-5:hover:after{
  width:100%;
  transition:800ms ease all;
}


/* 6 */
.btn-6 {
  background: rgb(247,150,192);
background: radial-gradient(circle, rgba(247,150,192,1) 0%, rgba(118,174,241,1) 100%);
  line-height: 42px;
  padding: 0;
  border: none;
}
.btn-6 span {
  position: relative;
  display: block;
  width: 100%;
  height: 100%;
}
.btn-6:before,
.btn-6:after {
  position: absolute;
  content: "";
  height: 0%;
  width: 1px;
 box-shadow:
   -1px -1px 20px 0px rgba(255,255,255,1),
   -4px -4px 5px 0px rgba(255,255,255,1),
   7px 7px 20px 0px rgba(0,0,0,.4),
   4px 4px 5px 0px rgba(0,0,0,.3);
}
.btn-6:before {
  right: 0;
  top: 0;
  transition: all 500ms ease;
}
.btn-6:after {
  left: 0;
  bottom: 0;
  transition: all 500ms ease;
}
.btn-6:hover{
  background: transparent;
  color: #76aef1;
  box-shadow: none;
}
.btn-6:hover:before {
  transition: all 500ms ease;
  height: 100%;
}
.btn-6:hover:after {
  transition: all 500ms ease;
  height: 100%;
}
.btn-6 span:before,
.btn-6 span:after {
  position: absolute;
  content: "";
  box-shadow:
   -1px -1px 20px 0px rgba(255,255,255,1),
   -4px -4px 5px 0px rgba(255,255,255,1),
   7px 7px 20px 0px rgba(0,0,0,.4),
   4px 4px 5px 0px rgba(0,0,0,.3);
}
.btn-6 span:before {
  left: 0;
  top: 0;
  width: 0%;
  height: .5px;
  transition: all 500ms ease;
}
.btn-6 span:after {
  right: 0;
  bottom: 0;
  width: 0%;
  height: .5px;
  transition: all 500ms ease;
}
.btn-6 span:hover:before {
  width: 100%;
}
.btn-6 span:hover:after {
  width: 100%;
}

/* 7 */
.btn-7 {
background: linear-gradient(0deg, rgba(255,151,0,1) 0%, rgba(251,75,2,1) 100%);
  line-height: 42px;
  padding: 0;
  border: none;
}
.btn-7 span {
  position: relative;
  display: block;
  width: 100%;
  height: 100%;
}
.btn-7:before,
.btn-7:after {
  position: absolute;
  content: "";
  right: 0;
  bottom: 0;
  background: rgba(251,75,2,1);
  box-shadow:
   -7px -7px 20px 0px rgba(255,255,255,.9),
   -4px -4px 5px 0px rgba(255,255,255,.9),
   7px 7px 20px 0px rgba(0,0,0,.2),
   4px 4px 5px 0px rgba(0,0,0,.3);
  transition: all 0.3s ease;
}
.btn-7:before{
   height: 0%;
   width: 2px;
}
.btn-7:after {
  width: 0%;
  height: 2px;
}
.btn-7:hover{
  color: rgba(251,75,2,1);
  background: transparent;
}
.btn-7:hover:before {
  height: 100%;
}
.btn-7:hover:after {
  width: 100%;
}
.btn-7 span:before,
.btn-7 span:after {
  position: absolute;
  content: "";
  left: 0;
  top: 0;
  background: rgba(251,75,2,1);
  box-shadow:
   -7px -7px 20px 0px rgba(255,255,255,.9),
   -4px -4px 5px 0px rgba(255,255,255,.9),
   7px 7px 20px 0px rgba(0,0,0,.2),
   4px 4px 5px 0px rgba(0,0,0,.3);
  transition: all 0.3s ease;
}
.btn-7 span:before {
  width: 2px;
  height: 0%;
}
.btn-7 span:after {
  height: 2px;
  width: 0%;
}
.btn-7 span:hover:before {
  height: 100%;
}
.btn-7 span:hover:after {
  width: 100%;
}

/* 8 */
.btn-8 {
  background-color: #f0ecfc;
background-image: linear-gradient(315deg, #f0ecfc 0%, #c797eb 74%);
  line-height: 42px;
  padding: 0;
  border: none;
}
.btn-8 span {
  position: relative;
  display: block;
  width: 100%;
  height: 100%;
}
.btn-8:before,
.btn-8:after {
  position: absolute;
  content: "";
  right: 0;
  bottom: 0;
  background: #c797eb;
  /*box-shadow:  4px 4px 6px 0 rgba(255,255,255,.5),
              -4px -4px 6px 0 rgba(116, 125, 136, .2),
    inset -4px -4px 6px 0 rgba(255,255,255,.5),
    inset 4px 4px 6px 0 rgba(116, 125, 136, .3);*/
  transition: all 0.3s ease;
}
.btn-8:before{
   height: 0%;
   width: 2px;
}
.btn-8:after {
  width: 0%;
  height: 2px;
}
.btn-8:hover:before {
  height: 100%;
}
.btn-8:hover:after {
  width: 100%;
}
.btn-8:hover{
  background: transparent;
}
.btn-8 span:hover{
  color: #c797eb;
}
.btn-8 span:before,
.btn-8 span:after {
  position: absolute;
  content: "";
  left: 0;
  top: 0;
  background: #c797eb;
  /*box-shadow:  4px 4px 6px 0 rgba(255,255,255,.5),
              -4px -4px 6px 0 rgba(116, 125, 136, .2),
    inset -4px -4px 6px 0 rgba(255,255,255,.5),
    inset 4px 4px 6px 0 rgba(116, 125, 136, .3);*/
  transition: all 0.3s ease;
}
.btn-8 span:before {
  width: 2px;
  height: 0%;
}
.btn-8 span:after {
  height: 2px;
  width: 0%;
}
.btn-8 span:hover:before {
  height: 100%;
}
.btn-8 span:hover:after {
  width: 100%;
}
 

/* 9 */
.btn-9 {
  border: none;
  transition: all 0.3s ease;
  overflow: hidden;
}
.btn-9:after {
  position: absolute;
  content: " ";
  z-index: -1;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
   background-color: #1fd1f9;
background-image: linear-gradient(315deg, #1fd1f9 0%, #b621fe 74%);
  transition: all 0.3s ease;
}
.btn-9:hover {
  background: transparent;
  box-shadow:  4px 4px 6px 0 rgba(255,255,255,.5),
              -4px -4px 6px 0 rgba(116, 125, 136, .2),
    inset -4px -4px 6px 0 rgba(255,255,255,.5),
    inset 4px 4px 6px 0 rgba(116, 125, 136, .3);
  color: #fff;
}
.btn-9:hover:after {
  -webkit-transform: scale(2) rotate(180deg);
  transform: scale(2) rotate(180deg);
  box-shadow:  4px 4px 6px 0 rgba(255,255,255,.5),
              -4px -4px 6px 0 rgba(116, 125, 136, .2),
    inset -4px -4px 6px 0 rgba(255,255,255,.5),
    inset 4px 4px 6px 0 rgba(116, 125, 136, .3);
}

/* 10 */
.btn-10 {
  background: rgb(22,9,240);
background: linear-gradient(0deg, rgba(22,9,240,1) 0%, rgba(49,110,244,1) 100%);
  color: #fff;
  border: none;
  transition: all 0.3s ease;
  overflow: hidden;
}
.btn-10:after {
  position: absolute;
  content: " ";
  top: 0;
  left: 0;
  z-index: -1;
  width: 100%;
  height: 100%;
  transition: all 0.3s ease;
  -webkit-transform: scale(.1);
  transform: scale(.1);
}
.btn-10:hover {
  color: #fff;
  border: none;
  background: transparent;
}
.btn-10:hover:after {
  background: rgb(0,3,255);
background: linear-gradient(0deg, rgba(2,126,251,1) 0%,  rgba(0,3,255,1)100%);
  -webkit-transform: scale(1);
  transform: scale(1);
}

/* 11 */
.btn-11 {
  border: none;
  background: rgb(251,33,117);
    background: linear-gradient(0deg, rgba(251,33,117,1) 0%, rgba(234,76,137,1) 100%);
    color: #fff;
    overflow: hidden;
}
.btn-11:hover {
    text-decoration: none;
    color: #fff;
}
.btn-11:before {
    position: absolute;
    content: '';
    display: inline-block;
    top: -180px;
    left: 0;
    width: 30px;
    height: 100%;
    background-color: #fff;
    animation: shiny-btn1 3s ease-in-out infinite;
}
.btn-11:hover{
  opacity: .7;
}
.btn-11:active{
  box-shadow:  4px 4px 6px 0 rgba(255,255,255,.3),
              -4px -4px 6px 0 rgba(116, 125, 136, .2),
    inset -4px -4px 6px 0 rgba(255,255,255,.2),
    inset 4px 4px 6px 0 rgba(0, 0, 0, .2);
}


@-webkit-keyframes shiny-btn1 {
    0% { -webkit-transform: scale(0) rotate(45deg); opacity: 0; }
    80% { -webkit-transform: scale(0) rotate(45deg); opacity: 0.5; }
    81% { -webkit-transform: scale(4) rotate(45deg); opacity: 1; }
    100% { -webkit-transform: scale(50) rotate(45deg); opacity: 0; }
}


/* 12 */
.btn-12{
  position: relative;
  right: 20px;
  bottom: 20px;
  border:none;
  box-shadow: none;
  width: 130px;
  height: 40px;
  line-height: 42px;
  -webkit-perspective: 230px;
  perspective: 230px;
}
.btn-12 span {
  background: rgb(0,172,238);
background: linear-gradient(0deg, rgba(0,172,238,1) 0%, rgba(2,126,251,1) 100%);
  display: block;
  position: absolute;
  width: 130px;
  height: 40px;
  box-shadow:inset 2px 2px 2px 0px rgba(255,255,255,.5),
   7px 7px 20px 0px rgba(0,0,0,.1),
   4px 4px 5px 0px rgba(0,0,0,.1);
  border-radius: 5px;
  margin:0;
  text-align: center;
  -webkit-box-sizing: border-box;
  -moz-box-sizing: border-box;
  box-sizing: border-box;
  -webkit-transition: all .3s;
  transition: all .3s;
}
.btn-12 span:nth-child(1) {
  box-shadow:
   -7px -7px 20px 0px #fff9,
   -4px -4px 5px 0px #fff9,
   7px 7px 20px 0px #0002,
   4px 4px 5px 0px #0001;
  -webkit-transform: rotateX(90deg);
  -moz-transform: rotateX(90deg);
  transform: rotateX(90deg);
  -webkit-transform-origin: 50% 50% -20px;
  -moz-transform-origin: 50% 50% -20px;
  transform-origin: 50% 50% -20px;
}
.btn-12 span:nth-child(2) {
  -webkit-transform: rotateX(0deg);
  -moz-transform: rotateX(0deg);
  transform: rotateX(0deg);
  -webkit-transform-origin: 50% 50% -20px;
  -moz-transform-origin: 50% 50% -20px;
  transform-origin: 50% 50% -20px;
}
.btn-12:hover span:nth-child(1) {
  box-shadow:inset 2px 2px 2px 0px rgba(255,255,255,.5),
   7px 7px 20px 0px rgba(0,0,0,.1),
   4px 4px 5px 0px rgba(0,0,0,.1);
  -webkit-transform: rotateX(0deg);
  -moz-transform: rotateX(0deg);
  transform: rotateX(0deg);
}
.btn-12:hover span:nth-child(2) {
  box-shadow:inset 2px 2px 2px 0px rgba(255,255,255,.5),
   7px 7px 20px 0px rgba(0,0,0,.1),
   4px 4px 5px 0px rgba(0,0,0,.1);
 color: transparent;
  -webkit-transform: rotateX(-90deg);
  -moz-transform: rotateX(-90deg);
  transform: rotateX(-90deg);
}


/* 13 */
.btn-13 {
  background-color: #89d8d3;
background-image: linear-gradient(315deg, #89d8d3 0%, #03c8a8 74%);
  border: none;
  z-index: 1;
}
.btn-13:after {
  position: absolute;
  content: "";
  width: 100%;
  height: 0;
  bottom: 0;
  left: 0;
  z-index: -1;
  border-radius: 5px;
   background-color: #4dccc6;
background-image: linear-gradient(315deg, #4dccc6 0%, #96e4df 74%);
  box-shadow:
   -7px -7px 20px 0px #fff9,
   -4px -4px 5px 0px #fff9,
   7px 7px 20px 0px #0002,
   4px 4px 5px 0px #0001;
  transition: all 0.3s ease;
}
.btn-13:hover {
  color: #fff;
}
.btn-13:hover:after {
  top: 0;
  height: 100%;
}
.btn-13:active {
  top: 2px;
}


/* 14 */
.btn-14 {
  background: rgb(255,151,0);
  border: none;
  z-index: 1;
}
.btn-14:after {
  position: absolute;
  content: "";
  width: 100%;
  height: 0;
  top: 0;
  left: 0;
  z-index: -1;
  border-radius: 5px;
  background-color: #eaf818;
  background-image: linear-gradient(315deg, #eaf818 0%, #f6fc9c 74%);
   box-shadow:inset 2px 2px 2px 0px rgba(255,255,255,.5);
   7px 7px 20px 0px rgba(0,0,0,.1),
   4px 4px 5px 0px rgba(0,0,0,.1);
  transition: all 0.3s ease;
}
.btn-14:hover {
  color: #000;
}
.btn-14:hover:after {
  top: auto;
  bottom: 0;
  height: 100%;
}
.btn-14:active {
  top: 2px;
}

/* 15 */
.btn-15 {
  background: #b621fe;
  border: none;
  z-index: 1;
}
.btn-15:after {
  position: absolute;
  content: "";
  width: 0;
  height: 100%;
  top: 0;
  right: 0;
  z-index: -1;
  background-color: #663dff;
  border-radius: 5px;
   box-shadow:inset 2px 2px 2px 0px rgba(255,255,255,.5),
   7px 7px 20px 0px rgba(0,0,0,.1),
   4px 4px 5px 0px rgba(0,0,0,.1);
  transition: all 0.3s ease;
}
.btn-15:hover {
  color: #fff;
}
.btn-15:hover:after {
  left: 0;
  width: 100%;
}
.btn-15:active {
  top: 2px;
}


/* 16 */
.btn-16 {
  border: none;
  color: #000;
}
.btn-16:after {
  position: absolute;
  content: "";
  width: 0;
  height: 100%;
  top: 0;
  left: 0;
  direction: rtl;
  z-index: -1;
  box-shadow:
   -7px -7px 20px 0px #fff9,
   -4px -4px 5px 0px #fff9,
   7px 7px 20px 0px #0002,
   4px 4px 5px 0px #0001;
  transition: all 0.3s ease;
}
.btn-16:hover {
  color: #000;
}
.btn-16:hover:after {
  left: auto;
  right: 0;
  width: 100%;
}
.btn-16:active {
  top: 2px;
}

<header>
   <link href="https://fonts.googleapis.com/css2?family=Lato&display=swap" rel="stylesheet">
</header>

<h1>Animation Buttons</h1>
<p>Hover us and enjoy the satisfying neumorphic animation designs!</p>
<div class="frame">
  <button class="custom-btn btn-1">Read More</button>
  <button class="custom-btn btn-2">Read More</button>
  <button class="custom-btn btn-3"><span>Read More</span></button>
  <button class="custom-btn btn-4"><span>Read More</span></button>
  <button class="custom-btn btn-5"><span>Read More</span></button>
  <button class="custom-btn btn-6"><span>Read More</span></button>
  <button class="custom-btn btn-7"><span>Read More</span></button>
  <button class="custom-btn btn-8"><span>Read More</span></button>
  <button class="custom-btn btn-9">Read More</button>
  <button class="custom-btn btn-10">Read More</button>
  <button class="custom-btn btn-11">Read More<div class="dot"></div></button>
  <button class="custom-btn btn-12"><span>Click!</span><span>Read More</span></button>
  <button class="custom-btn btn-13">Read More</button>
  <button class="custom-btn btn-14">Read More</button>
  <button class="custom-btn btn-15">Read More</button>
  <button class="custom-btn btn-16">Read More</button>
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</div>