toTop.addEventListener('click', function(){
    window.scrollTo({ top: 0, behavior: 'smooth' });
  });

  /* 当前浏览板块的导航高亮 */
  var sections = ['home','classic','family','urban','suspense','retro','award','ranking','news','faq','comment']
    .map(function(id){ return document.getElementById(id); })
    .filter(Boolean);

  var navLinks = document.querySelectorAll('.nav-list a, .nav-mobile a');

  function markActive(){
    var pos = window.pageYOffset + 130;
    var activeId = sections.length ? sections[0].id : '';
    for(var i = 0; i < sections.length; i++){
      if(sections[i].offsetTop <= pos){ activeId = sections[i].id; }
    }
    for(var j = 0; j < navLinks.length; j++){
      var href = navLinks[j].getAttribute('href') || '';
      if(href === '#' + activeId){
        navLinks[j].classList.add('is-current');
      }else{
        navLinks[j].classList.remove('is-current');
      }
    }
  }

  window.addEventListener('scroll', markActive, { passive:true });
  markActive();

})();
</script>

<style>
  .nav-list a.is-current,
  .nav-mobile a.is-current{
    color:#fff;
    background:rgba(226,72,60,.22);
  }
  .nav-list a.is-current.nav-cta{
    color:#12161d;
  }
</style>

</body>
</html>