HTML_CSS_FULL_COURSE/buttons.html

<style>
  .subscribe-button {
    background-color: rgb(204, 0, 0);
    color: white;
    border: none;
    border-radius: 2px;
    padding-top: 10px;
    padding-bottom: 10px;
    padding-left: 16px;
    padding-right: 16px;
    cursor: pointer;
    margin-right: 12px;
    transition: opacity 0.15s;
    vertical-align: top;
  }
  
  .subscribe-button:hover {
      opacity: 0.8;
  }
  
  .subscribe-button:active {
      opacity: 0.5;
  }

  .join-button {
      background-color: rgb(255, 255, 255); 
      color: rgb(6, 95, 212);
      border-color: rgb(6, 95, 212);
      border-style: solid;
      border-width: 1px;
      padding-top: 9px;
      padding-bottom: 9px;
      padding-left: 16px;
      padding-right: 16px;
      vertical-align: top;
      border-radius: 2px;
      cursor: pointer; 
      transition: background-color 0.15s,
        color 0.15s;
  }

  .join-button:hover {
      background-color: rgb(6, 95, 212);
      color: rgb(255, 255, 255);
  }

  .join-button:active {
      opacity: 0.7;
  }

  .tweet-button {
      background-color: rgb(29, 155, 240);
      color: white;
      border: none;
      padding-top: 7px;
      padding-bottom: 7px;
      padding-left: 16px;
      padding-right: 16px;
      border-radius: 16px;
      font-weight: bold;
      font-size: 15px;
      cursor: pointer; 
      margin-left: 12px;
      transition: box-shadow 0.15s;
  }

  .tweet-button:hover {
      box-shadow: 5px 5px 10px rgba(0,0,0,.15);
  }

</style>

<button class="subscribe-button">
    SUBSCRIBE
</button>
<button class="join-button">
    JOIN
</button>
<button class="tweet-button">
    Tweet
</button>