SOURCE

<div class="wrap">
  <h1 class="header">番茄时钟</h1>
  <div class="btn-container">
    <div class="btn-left">
      <div class="btn-title">工作时间</div>
      <div class="btn-content">
        <span>-</span>
        <span>5</span>
        <span>+</span>
      </div>
    </div>
    <div class="btn-right">
      <div class="btn-title">休息时间</div>
       <div class="btn-content">
        <span>-</span>
        <span>5</span>
        <span>+</span>
      </div>
    </div>
  </div>
  <div class="clock">
    <div class="clock-start">开始</div>
    <div class="clock-time" id='clock-time'>11111</div>
  </div>
</div>

* {
  margin: 0;
  padding: 0;
}

html,body {
  background: #aaa;
}

.wrap {
  text-align: center;
  color: #fff;
  .header {
    margin: 20px;
  }
  .btn-container {
    .btn-left {
      display: inline-block;
      margin-right: 40px;
    }
    .btn-right {
      display: inline-block;
      margin-left: 40px;
    }
  }
  .clock {
    margin: 0 auto;
    width: 300px;
    height: 300px;
    border: 1px solid #fff;
    border-radius: 50%;
    position: relative;
    .clock-start {
      font-size: 36px;
      padding-top: 50px;
    }
    .clock-time {
      font-size: 40px;
      padding-top: 50px;
    }
  }
}