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HTML 

              
                <section>
  <h1>Loading Button</h1>
  <button class="button-pulse">
    <span>Loading</span>
   </button>
</section>

<a href="https://www.studioalex.dev/" target="_blank" class="studioalex-logo">
  <div class="studioalex">
    <svg width="0" height="0">
      <defs>
        <clipPath id="alex-clippath" clipPathUnits="objectBoundingBox">
          <path transform="scale(0.00252525, 0.00245098)" d="M196.538 5.51918C195.668 3.49358 193.154 3.49362 192.478 5.51918C191.801 7.54474 138.333 139.883 138.333 139.883L143.748 142.584L159.991 102.747L273.694 394.432H230.379V399.833H391.458V394.432H352.204C352.204 394.432 197.409 7.54478 196.538 5.51918Z" fill="white" stroke="white" stroke-width="8" />
          <path transform="scale(0.00252525, 0.00245098)" d="M187.292 240.836V235.435C26.6051 211.128 78.5917 390.053 5 396.129C5 399.505 5.00161 398.155 5 401.531C165.687 427.863 119.101 234.76 187.292 240.836Z" fill="white" stroke="white" stroke-width="8" />
        </clipPath>
      </defs>
    </svg>
  </div>
</a>
!

CSS 

              
                @use postcss-nested;
@import url('https://fonts.googleapis.com/css2?family=Open+Sans:wght@400;500;600;700&display=swap');

:root {
  --pulse-color: hsl(187 97.5% 69.2%);
  --body-background-color: hsl(201 37.7% 12%);
}

html,
body {
  height: 100%;
}

body {
  display: grid;
  justify-content: center;
  align-content: center;
  background-color: #0f222b;
  padding: 20pt;
  box-sizing: border-box;
}

* {
  padding: 0;
  margin: 0;
}

section {
  text-align: center;
}

h1 {
  margin: 0 0 6rem 0;
  font-family: 'Montserrat', sans-serif;
  font-weight: 900;
  font-size: 38px;
  color: white;
}



.button-pulse {
  --btn-border-radius: 6pt;
  position: relative;
  min-height: 30pt;
  padding: 0.25em 1.25em;
  font-family: 'Open Sans', sans-serif;
  font-size: 26px;
  font-weight: 600;
  letter-spacing: 0.15pt;
  text-align: center;
  text-decoration: none;
  white-space: nowrap;
  text-overflow: ellipsis;
  cursor: pointer;
  user-select: none;
  outline: 0 solid transparent;
  border-radius: var(--btn-border-radius);
  border: 1pt solid var(--pulse-color);
  background-color: var(--pulse-color);
  
  &::before {
    position: absolute;
    content: "";
    top: 0;
    bottom: 0;
    left: 0;
    right: 0;
    outline: 2pt solid var(--pulse-color);
    border-radius: var(--btn-border-radius);
    outline-offset: 2pt;
    outline-width: 2pt;
    animation: pluseButton 0.9s ease-out infinite;
  }
}

@keyframes pluseButton {
  from {
    outline-offset: 2pt;
    opacity: 1;
  }
  to {
    outline-offset: 10pt;
    opacity: 0;
    outline-width: 10pt;
  }
}

/* ---------- logo --------*/
.studioalex {
  display: inline-block;
  background-image: linear-gradient(45deg, rgb(246,46,36), rgb(255,133,27), rgb(255,221,0), rgb(46,204,64), rgb(0,116,217), rgb(176,13,201));
  background-size: 800% 800%;
  clip-path: url(#alex-clippath);
  height:30px;
  width: 30px;
  isolation: isolate;
  animation: rainbow 15s ease alternate infinite;
  
  &-logo {
    position: fixed;
    padding: 5px 5px 10px 8px;
    top: 20px;
    left: 20px;
    background-color: hsl(201 37.7% 22%);
    border-radius: 50%;
    
    &:hover {
      background-color: var(--pulse-color);
    }
  }
}

@keyframes rainbow {
  0% {
    background-position: 1% 80%;
  }
  50% {
    background-position: 99% 20%;
  }
  100% {
    background-position: 1% 80%;
  }
}
!

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