เราสามารถกำหนดสไตล์สำหรับหน้าเว็บในโหมดเต็มหน้าจอได้โดยใช้ CSS :fullscreen pseudo-class
ไวยากรณ์ (Syntax)
Selector:fullscreen {
attribute: /*value*/
}
ตัวอย่างที่ 1: เปลี่ยนสีพื้นหลังและขนาดตัวอักษร
<!DOCTYPE html>
<html>
<head>
<style>
* {
margin: 3%;
}
:fullscreen {
background-color: thistle;
font-size: 2em;
}
:-webkit-full-screen {
background-color: thistle;
font-size: 2em;
}
:-ms-fullscreen {
background-color: thistle;
font-size: 2em;
}
</style>
</head>
<body onclick="fullScreenNow();">
<p> Proin eleifend quam nunc, et ultrices neque euismod a.</p>
<p>Nulla eleifend tempus tempor. Nam non nibh imperdiet est interdum eleifend vitae quis augue. Vivamus aliquam dolor vel elit semper egestas. Fusce consequat dolor nisl, eu interdum ex mattis id. Suspendisse consectetur ligula libero, vel pharetra tortor varius id. Nulla arcu lorem, convallis a erat vel, suscipit rutrum leo.</p>
<script>
let item = document.documentElement;
function fullScreenNow() {
if (item.requestFullscreen) {
item.requestFullscreen();
} else if (item.webkitRequestFullscreen) {
item.webkitRequestFullscreen();
} else if (item.msRequestFullscreen) {
item.msRequestFullscreen();
}
}
</script>
</body>
</html>
ผลลัพธ์
จะได้ผลลัพธ์ดังนี้:

ตัวอย่างที่ 2: ใช้ภาพพื้นหลังเต็มหน้าจอ
<!DOCTYPE html>
<html>
<head>
<style>
* {
margin: 3%;
color: white;
box-shadow: inset 0 0 40px green;
}
:fullscreen {
background: url("https://images.unsplash.com/photo-1612149413930-72410fd9a021?crop=entropy&cs=tinysrgb&fit=crop&fm=jpg&h=1080&ixlib=rb1.2.1&q=80&w=1920") no-repeat;
font-size: 2em;
}
:-webkit-full-screen {
background: url("https://images.unsplash.com/photo-1612149413930-72410fd9a021?crop=entropy&cs=tinysrgb&fit=crop&fm=jpg&h=1080&ixlib=rb1.2.1&q=80&w=1920") no-repeat;
font-size: 2em;
}
:-ms-fullscreen {
background: url("https://images.unsplash.com/photo-1612149413930-72410fd9a021?crop=entropy&cs=tinysrgb&fit=crop&fm=jpg&h=1080&ixlib=rb1.2.1&q=80&w=1920") no-repeat;
font-size: 2em;
}
</style>
</head>
<body onclick="fullScreenNow();">
<p> Proin eleifend quam nunc, et ultrices neque euismod a.</p>
<p>Nulla eleifend tempus tempor. Nam non nibh imperdiet est interdum eleifend vitae quis augue. Vivamus aliquam dolor vel elit semper egestas. Fusce consequat dolor nisl, eu interdum ex mattis id. Suspendisse consectetur ligula libero, vel pharetra tortor varius id. Nulla arcu lorem, convallis a erat vel, suscipit rutrum leo.</p>
<script>
let item = document.documentElement;
function fullScreenNow() {
if (item.requestFullscreen) {
item.requestFullscreen();
} else if (item.webkitRequestFullscreen) {
item.webkitRequestFullscreen();
} else if (item.msRequestFullscreen)
item.msRequestFullscreen();
}
}
</script>
</body>
</html>
ผลลัพธ์
จะได้ผลลัพธ์ดังนี้:

