字体大小 rem 不能在不同的屏幕上缩放

Question

缩小屏幕尺寸时，字体和元素不会缩放。以下是代码。在开发人员工具中，如果我更改根 HTML 字体大小，字体和相应的元素会缩放，但是当屏幕大小减小时，它不会。

/*
    COLORS:
    
    Light green: #7ed56f
    Medium green: #55c57a
    Dark green: #28b485
    font-grey: #777777
    
    */

* *::after,
*::before {
  margin: 0;
  padding: 0;
  box-sizing: inherit;
}

html {
  font-size: 62.5%;
}

body {
  font-family: "Lato", sans-serif;
  font-weight: 400;
  line-height: 1.7;
  color: #777777;
  padding: 3rem;
  box-sizing: border-box;
}

.header {
  height: 95vh;
  /*95% of screen*/
  background-image: linear-gradient( to right bottom, rgba(126, 213, 111, 0.8), rgba(23, 133, 96, 0.8)), url(../img/hero.jpg);
  background-size: cover;
  /*image adapts to the screen*/
  background-position: top;
  /* top of the image stays the same  whatever the screen size*/
  clip-path: polygon(0 0, 100% 0, 100% 70vh, 0 100%);
  position: relative;
}

.logo-box {
  position: absolute;
  top: 4rem;
  left: 4rem;
}

.logo {
  height: 3.5rem;
}

.text-box {
  position: absolute;
  top: 40%;
  left: 50%;
  transform: translate(-50%, -50%);
  text-align: center;
}

.heading-primary {
  color: #ffffff;
  text-transform: uppercase;
  backface-visibility: hidden;
  /*part behind the element gets hidden*/
  margin-bottom: 4rem;
}

.heading-primary-main {
  display: block;
  font-size: 6rem;
  font-weight: 400;
  letter-spacing: 3.5rem;
  animation-name: left;
  animation-duration: 1s;
  animation-timing-function: ease-out;
  /* animation-iteration-count: 2;
        animation-delay: 2; */
}

.heading-primary-sub {
  display: block;
  font-size: 2rem;
  font-weight: 700;
  letter-spacing: 2.1rem;
  animation: left 1s ease-out;
}

@keyframes right {
  from {
    opacity: 0;
    transform: translateX(10rem);
  }
  80% {
    transform: translateX(-1rem);
  }
  to {
    opacity: 1;
    transform: translate(0);
  }
}

@keyframes left {
  from {
    opacity: 0;
    transform: translateX(-10rem);
  }
  80% {
    transform: translateX(1rem);
  }
  to {
    opacity: 1;
    transform: translate(0);
  }
}

@keyframes button {
  from {
    opacity: 0;
    transform: translateY(2rem);
  }
  to {
    opacity: 1;
    transform: translate(0);
  }
}

.btn-animated {
  animation: button 0.5s ease-out 0.75s;
  animation-fill-mode: backwards;
}

.btn:link,
.btn:visited {
  text-decoration: none;
  text-transform: uppercase;
  padding: 1.5rem 4rem;
  display: inline-block;
  border-radius: 10rem;
  transition: all 0.5s;
  position: relative;
  font-size: 1.6rem;
}

.btn:hover {
  transform: translateY(-3px);
  box-shadow: 0 1rem 2rem rgba(0, 0, 0, 0.5);
  /* x-axis y-axis blur color */
}

.btn:active {
  transform: translateY(-1px);
  box-shadow: 0 0.5rem 1rem rgba(0, 0, 0, 0.8);
}

.btn-white {
  background-color: #fff;
  color: #777777;
}

.btn::after {
  content: "";
  display: inline-block;
  height: 100%;
  width: 100%;
  border-radius: 10rem;
  position: absolute;
  top: 0;
  left: 0;
  z-index: -1;
  transition: all 0.4s;
}

.btn-white::after {
  background-color: #fff;
}

.btn:hover::after {
  transform: scaleX(1.2) scaleY(1.4);
  opacity: 0;
}

<link href="https://fonts.googleapis.com/css?family=Lato:100,300,400,700,900" rel="stylesheet">
<header class="header">
  <div class="logo-box">
    <img src="img/logo-white.png" alt="Logo Natours" class="logo">
  </div>
  <div class="text-box">
    <h1 class="heading-primary">
      <span class="heading-primary-main">Outdoors</span>
      <span class="heading-primary-sub">Where life happens</span>
    </h1>
    <a href="#" class="btn btn-white btn-animated">Discover Our Tours</a>
  </div>
</header>
<div>
</div>

Answer 1

CSS 不能那样工作。您需要媒体查询才能根据屏幕宽度设置不同的字体大小。

即你需要告诉你的浏览器，当屏幕变宽或变宽（或变小）时，将字体大小更改为 Y。

这适用于您希望字体大小适用于 601px

的所有内容

@media screen and (min-width: 601px) {
  div.example {
    font-size: 80px;
  }
}

这适用于您希望字体大小适用于低于 601px

的所有内容

@media screen and (min-width: 601px) {
  div.example {
    font-size: 80px;
  }
}