1. Form submission
<!doctype html>
Action: The address requested when the form was submitted
Method: Methods for form requests, either post or get
When the type of input is submit, the Click button submits the contents of the form as a key-value pair, the value of the key name is name, and the value is the value of input
2. Weights for CSS SelectorsThe weight value of the label is 1, the weight of the class is 10,id 100, the weight level is the same, then the accumulation, when the style conflicts, the weight of the high value of the effective
3. Box modelMargin border padding
The box model occupies High: "width" + "margin-left" + "margin-right" + "Border-left" + "border-right" + "Padding-left" + "Padding-right"
Box model width is similar to height
However, in a streaming layout, margin-top and margin-bottom may overlap
4. Relative combined with absolute<body><div id= "Box1" ><div id= "Box2" > Relative reference elements for positioning </div></div>
#box1 { width:200px; height:200px; position:relative; } #box2 {
Position:absolute; top:20px; left:30px; }
HTML CSS Basics