Some of the basics of css

The best way to remove floating (add this property on the parent element)

.clearfix::after {
    content: "";
    display: block;
    clear: both;
}

Select the first of several juxtaposed elements provided for this property (now set to a multiple of six bits) * /

main .movies:nth-child(6n){
    margin-right: 0;
}

position
default values: static, static positioning (not positioned)
relative: the relative positioning
absolute: absolute positioning
fixed: fixed positioning * /

Border arc of 50% (that is, a circle) * /

    border-radius: 50%;

If the mouse across the width of the time will cause a similar increase in the phenomenon of jitter (width can only solve the problem)

(Height can only be solved by temporarily reducing the high line across) /
width and height is provided comprising a filler content comprising /

box-sizing:border-box;

The method of setting translucent * /

background-color:rgba(0,0,0,0.5)

The effect of the mouse pointer icon appears and a small element that comes into the hands of the element * /

cursor: pointer;

Select first child

:first-child

The first child element specifies the type of the selected elements

:first-of-type

Select the last child element

:last-child

Select the last child element specifies the type of element

:last-of-type

Select the first of several sub-elements specified

Child-Nth
the even: keywords, is equivalent to 2N
ODD: keywords, equivalent to 2n + 1

Select the child element specified in the first few certain types of elements

nth-of-type

transparency

1. Opacity, provided it is transparent to the entire element (including sub-elements), its value is 0 to 1
2. Set alpha channel (RGBA) color position