<div class="container">
  <button class="button primary" type="button">1️⃣我是button元素(未设置tabindex)💯</button>
    <div class="button primary" role="button">2️⃣我是div元素(未设置tabindex)♨️</div>
    <button class="button success" type="button" tabindex="-1">3️⃣我是button元素(tabindex="-1")💯</button>
    <div class="button success" role="button" tabindex="-1">4️⃣我是div元素(tabindex="-1")♨️</div>
    <button class="button danger" type="button" tabindex="0">5️⃣我是button元素(tabindex="0")💯</button>
    <div class="button danger" role="button" tabindex="0">6️⃣我是div元素(tabindex="0")♨️</div>
    <button class="button warning" type="button" tabindex="">7️⃣我是button元素(tabindex="")💯</button>
    <div class="button warning" role="button" tabindex="">8️⃣我是div元素(tabindex="")♨️</div>
</div>

@import 'https://fonts.googleapis.com/css?family=Share+Tech+Mono';

@import 'https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css';

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
    width: 100vw;
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    background-image: url('https://s3-us-west-2.amazonaws.com/s.cdpn.io/1376484/jess-harding-lqT6NAmTaiY-unsplash.jpg'),radial-gradient(#28a3dd, #0d7751);
    background-size: cover;
    background-position: center;
    font-family: "Share Tech Mono", monospace;
    font-size: 2rem;
    background-blend-mode: multiply,screen, overlay;
}

.container {
    position: relative;
    background-size: cover;
    background-position: center;
    backdrop-filter: blur(20px);
    background-color: rgba(255, 255, 255, 0.5);
    border-radius: 5px;
    padding:2vw;
    box-sizing: border-box;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.12), 0 1px 2px rgba(0, 0, 0, 0.24);
    transition: .3s ease;
    margin: 3vw;
    min-width: 80vw;
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(30vw, 1fr));
    grid-gap: 10px;
}

.button {
	display: inline-flex;
	font-size: 16px;
	font-weight: 700;
	border-radius: 5px;
	transition: background .3s;
  padding: 4vh 6vh;
  background: #11a8ab;
  border: none 0;
  color: #fff;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  
  &.primary {
    background: #007bff;
    
    &:hover {
      background: #0069d9;
    }
  }
  
  &.success{
    background: #28a745;
    
    &:hover {
      background: #218838;
    }
  }
  
  &.danger {
    background: #dc3545;
    
    &:hover {
      background: #c82333;
    }
  }
  
  &.warning {
    background: #17a2b8;
    
    &:hover {
      background: #138496;
    }
  }
}


.button:focus,
.button:active {
    box-shadow: inset 0 0 3px  3px #0a166f;
}