<template>
  <div id="index">
    <div class="toTop" v-show="showTop" @click="toTop">
      <img src="../assets/img/angle-square-up.png" alt="" width="35px" />
    </div>
  </div>
</template>
<script>
export default {
  data() {
    return {
      showTop: false,
    };
  },
  mounted() {
    // 添加監(jiān)聽(tīng)事件
    window.addEventListener("scroll", this.scrolling);
  },
  methods: {
  	// 監(jiān)聽(tīng)事件
    scrolling() {
      let current =
        document.documentElement.scrollTop || document.body.scrollTop;
      let vh = window.innerHeight;
      if (current >= vh) {
        this.showTop = true;
      } else {
        this.showTop = false;
      }
    },
    // 點(diǎn)擊事件
    toTop() {
      // 獲取當(dāng)前滾動(dòng)條的位置
      let top = document.documentElement.scrollTop || document.body.scrollTop;
      // 滾動(dòng)動(dòng)畫(huà)
      const timeTop = setInterval(() => {
        document.body.scrollTop =
          document.documentElement.scrollTop =
          top -=
            50;
        if (top <= 0) {
          clearInterval(timeTop);
        }
      }, 10);
    },
  },
};
</script>
<style lang="scss" scoped>
#index {
  .toTop {
    position: fixed;
    right: 20px;
    bottom: 20px;
    cursor: pointer;
    width: 35px;
    height: 35px;
    z-index: 2;
    opacity: 0.3;
  }
}
img:hover {
  opacity: 0.5;
}
</style>

<template>
  <div id="navigation">
    <ul class="part1">
      <li>LOGO</li>
    </ul>
    <ul class="part2">
      <!-- href="/" rel="external nofollow"  rel="external nofollow"  跳轉(zhuǎn)到首頁(yè) -->
      <li><a href="/" rel="external nofollow"  rel="external nofollow" >HOME</a></li>
      <!-- href="/#about" rel="external nofollow"  rel="external nofollow"  跳轉(zhuǎn)到首頁(yè)的id為about的元素位置 -->
      <li><a href="/#about" rel="external nofollow"  rel="external nofollow" >ABOUT</a></li>
      <li><a href="/#paper" rel="external nofollow" >PAPER</a></li>
      <li><a href="/#team" rel="external nofollow" >TEAM</a></li>
    </ul>
  </div>
</template>
<style lang="scss" scoped>
#navigation {
  width: 94vw;
  height: 60px;
  margin: 0 auto;
  // 彈性布局
  display: flex;
  justify-content: space-between;
  align-items: center;
  .part2 {
    // 彈性布局
    display: flex;
    justify-content: center;
    align-items: center;
  }
  li {
    width: 100px;
    height: 40px;
    line-height: 40px;
    font-weight: bold;
    a:link {
      color: #8e9eab;
    }
    a:visited {
      color: #8e9eab;
    }
    a:hover {
      color: #4f4f4f;
    }
    a:active {
      color: #4f4f4f;
    }
  }
}
</style>

a {
	// 清除默認(rèn)下劃線
    text-decoration: none;
}
// 超鏈接初始樣式
a:link {
    color: #8e9eab;
}
// 超鏈接被訪問(wèn)后的樣式
a:visited {
    color: #8e9eab;
}
// 鼠標(biāo)懸停時(shí)的樣式
a:hover {
    color: #4f4f4f;
}
// 點(diǎn)擊超鏈接時(shí)的樣式
a:active {
    color: #8e9eab;
}