<div class="wrapper">
  <button class="button button1">
    <span class="button-content">Empty Gradient button</span>
  </button>
  <button class="button button2">Primary Gradient button</button>
  <button class="button button3">Secondary Grey Button</button>
  <button class="button button3 button3--active">Secondary Active Button</button>
  <button class="button button4">Ghost Button</button>
</div>

:root {
  --textColor1: #008cff;
  --textColor2: #fff;
  --textColor3: #737594;
}

html, body {
  height: 100%;
}
body {
  background-color: #0e0e30;
  margin: 0;
}
.wrapper {
  height: 100%;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  padding: 60px;
}

.button {
  display: block;
  margin: 20px 0;
  min-height: 50px;
  padding: 13px 24px;
  font-family: 'Lucida Grande', 'Helvetica', sans-serif;
  font-size: 16px;
  line-height: 20px;
  font-weight: bold;
  text-transform: uppercase;
  text-align: center;
  border: none;
  border-radius: 4px;
  outline: none;
  box-shadow: none;
  background-color: transparent;
  background-position: top center;
  cursor: pointer;
  transition: 0.3s ease-in-out;
  transition-property: background, color;
}

.button1 {
  position: relative;
  display: block;
  color: var(--textColor1);
  border-radius: 26px;
  box-sizing: border-box;
  border: 2px solid transparent;
  background-color: #0e0e30;
  background-clip: padding-box;
  overflow: hidden;
  z-index: 1;
  
  &::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    right: 0;
    border: 2px solid transparent;
    background-image: linear-gradient(#0e0e30, #0e0e30), linear-gradient(90deg, #008cff, #6942ef);
    background-clip: padding-box, border-box;
  background-repeat: repeat-x;
  background-size: calc(100% + 2px * 2) calc(100% + 2px * 2);
  background-position: center;
    border-radius: 26px;
    z-index: -1;
    transition: border-color 0.2s;
  }
  
  &::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 70vmax;
    height: 70vmax;
    border-radius: 50%;
    background-image: linear-gradient(90deg, #008cff, #6942ef);
    transform-origin: center;
    transform: translate(-50%, -50%) scale(0);
    transition: transform 0.4s ease-in-out;
    z-index: -1;
  }
  
  &:hover {
    color: var(--textColor2);
    &::after {
      transform: translate(-50%, -50%) scale(1);
    }
  }
  
  &:active {
    color: #c3c4d5;
  }
  
  &:focus {
    color: white;
    &::before {
      border-color: #00b8d9;
    }
  }
}

.button2 {
  position: relative;
  color: var(--textColor2);
  border-radius: 26px;
  background-image: linear-gradient(90deg, #0065ff, #6942ef, #6554c0, #008cff, #0065ff, #6942ef);
  background-size: 400%;
  background-position: 0% 0%;
  
  &::before {
    content: '';
    position: absolute;
    left: -2px;
    top: -2px;
    right: -2px;
    bottom: -2px;
    border-radius: 26px;
    background-image: linear-gradient(90deg, #0065ff, #6942ef, #6554c0, #008cff, #0065ff, #6942ef);
    background-size: 500%;
    background-position: 0% 0%;
    filter: blur(10px);
    opacity: 0;
    z-index: -1;
    transition: opacity 0.2s;
  }
  
  &:hover {
    animation: gradientRotate 2s infinite;
    &::before {
      opacity: 1;
      animation: gradientRotate 2s infinite;
    }
  }
  
  &:active {
    color: #c3c4d5;
  }
  
  &:focus {
    &::before {
      opacity: 1;
    }
  }
}

.button3 {
  position: relative;
  border-radius: 26px;
  color: var(--textColor3);
  background-color: transparent;
  border: 2px solid transparent;
  background-clip: padding-box;
  overflow: hidden;
  z-index: 1;
  
  &::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    right: 0;
    border: 2px solid #313152;
  background-position: center;
    border-radius: 26px;
    z-index: -1;
    transition: border-color 0.2s;
  }
  
  &::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 70vmax;
    height: 70vmax;
    border-radius: 50%;
    background-color: #737594;
    opacity: 0.3;
    transform-origin: center;
    transform: translate(-50%, -50%) scale(0);
    transition: transform 0.4s ease-in-out;
    z-index: -1;
  }
  
  &--active::after {
    background-color: #f7841d;
    opacity: 1;
  }
    
  &:focus {
    color: var(--textColor2);
    &::before {
      border-color: #737594;
    }
  }
  
  &:hover, &:hover:focus {
    color: var(--textColor2);
    &::after {
      transform: translate(-50%, -50%) scale(1);
    }
  }
  
  &:active {
    color: #c3c4d5;
  }
}

.button4 {
  position: relative;
  border-radius: 26px;
  color: var(--textColor3);
  border: none;
  overflow: hidden;
  z-index: 1;
  
  &::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    right: 0;
    background-color: #0e0e30;
    background-clip: padding-box;
    border: 2px solid transparent;
    border-radius: 26px;
    z-index: -1;
    transition: border-color 0.2s;
  }
  
  &::after {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    right: 0;
    background-color: #737594;
    border-radius: 26px;
    z-index: -2;
    transform: translate(-150%, -150%);
    transform-origin: left top;
    transition: transform 0.2s;
  }
  
  &:hover {
    color: white;
    
    &::after {
      transform: translate(0, 0);
    }
  }
  
  &:active {
    color: #c3c4d5;
  }
  
  &:focus {
    color: #d8d8e3;
  }
}

@keyframes gradientRotate {
  0% {
    background-position: 0% 0%;
  }
  100% {
    background-position: 100% 100%;
  }
}