字体大小 rem 无法在不同的屏幕上缩放

Question

当屏幕尺寸减小时，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，但是当屏幕尺寸减小时，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 不是那样工作的。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，您需要告诉您的浏览器，当屏幕宽度或更宽(或更小(时，将字体大小更改为 Y。

当您希望字体大小适用于 601px以上的所有内容时，这适用于

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

当您希望字体大小适用于 601px以下的所有内容时

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