该媒体查询适配规则是以UI设计图750p宽度为版本的，比如PS量的是450px，在书写时写 (450rem/2/15).
@media (min-240px) and (max-320px){html{font-size:12.8px!important}}
@media (min-321px) and (max-360px){html{font-size:14.4px!important}}
@media (min-361px) and (max-375px){html{font-size:15px!important}}
@media (min-376px) and (max-384px){html{font-size:15.36px!important}}
@media (min-385px) and (max-414px){html{font-size:16.56px!important}}
@media (min-415px) and (max-450px){html{font-size:18px!important}}
@media (min-451px) and (max-500px){html{font-size:20px!important}}
@media (min-501px) and (max-550px){html{font-size:22px!important}}
@media (min-551px) and (max-569px){html{font-size:22.72px!important}}
@media (min-569px) and (max-640px){html{font-size:25.6px!important}}
@media (min-641px) and (max-667px){html{font-size:26.68px!important}}
@media (min-668px) and (max-736px){html{font-size:29.44px!important}}
@media (min-738px) and (max-768px){html{font-size:30.72px!important}}
@media (min-769px) and (max-900px){html{font-size:36px!important}}
@media (min-901px) and (max-1080px){html{font-size:43.24px!important}}