In đậm chữ trong css w3schools

The w3-left-align and the w3-right-align classes are used to align text.

Left aligned text.

Right aligned text.

<div class=”w3-container w3-border w3-large”>
  <div class=”w3-left-align”><p>Left aligned text.</p></div>
  <div class=”w3-right-align”><p>Right aligned text.</p></div>
</div>

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The w3-center class is used to center-align elements:

Some centered text.

<div class=”w3-container w3-center”>
  <h2>Centered Content</h2>
  <img src=”img_car.jpg” alt=”car” style=”width:80%;max-width:320px”>
  <p>Some centered text.</p>
</div>

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The w3-wide class specifies a wider text:

This text is normal.

This text is wider.

<p class=”w3-wide”>The w3-wide class
specifies a wider text.</p>

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The w3-opacity class is designed to work with all colors:

<div class=”w3-panel w3-pink”>
  <h2
class=”w3-opacity”>Text Opacity</h2>
</div>

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The CSS3 text-shadow property can be used to add shadow or blur effects to text:

<h2 class=”w3-blue”
style=”text-shadow:1px 1px 0 #444″>Text Shadow</h2>

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<div class=”w3-panel w3-pink”>
  <h2 class=”w3-opacity”>
 
<b>Text Opacity + Bold</b></h2>
</div>

<div class=”w3-panel w3-amber”>
  <h2 class=”w3-text-yellow” style=”text-shadow:1px 1px 0 #444″>
  <b>Yellow Text + Shadow + Bold</b></h2>
</div>

<div class=”w3-panel w3-blue”>
  <h2 class=”w3-text-orange” style=”text-shadow:1px 1px 0 #444″>
  <b>Orange Text + Shadow + Bold</b></h2>
</div>

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Text Shadow does not work in IE 9 and earlier.

Set different font weight for three paragraphs:

p.normal {
  font-weight: normal;
}

p.thick {
  font-weight: bold;
}

p.thicker {
  font-weight: 900;
}

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The font-weight property sets how thick or thin characters in
text should be displayed.

Show demo ❯

The numbers in the table specify the first browser version that fully supports the property.

font-weight: normal|bold|bolder|lighter|number|initial|inherit;

CSS tutorial: CSS Font

CSS reference: font property

HTML DOM reference: fontWeight property