How to pinch the middle of a line in css

问题

I'm trying to make a line that almost looks like it has serifs at the ends. Essentially, I want to make it wider at the very ends and thin in the middle, just using css. This has actually proven to be quite a challenge.

Any help would be appreciated.

Thus far I've been able to get the bottom to look how I want using the :after pseudo selector, but no luck with the top, which I can only seem to get concave, rather than convex.

Here's the code of what I've done so far

    .line {
        background:none;
        height: 8px;
        position:relative;
        overflow:hidden;
        z-index:1;
        top: 50px;
        left: 50px;
        width: 140px;
        box-shadow: 11px 12px 16px -3px rgba(0,0,0,0.6);
        -webkit-transform: rotate(38deg);
        transform: rotate(38deg);
    }
    .line:after {
        content: '';
        position: absolute;
        left: 0%;
        width: 100%;
        padding-bottom: 10%;
        top: 50%;
        border-radius: 35%;
        box-shadow: 0px 0px 0px 150px rgba(0,0,0,0.6);
        z-index: -1;
    }
    .line:before {
        content: '';
        position: absolute;
        left: 0%;
        width: 100%;
        padding-bottom: 8%;
        top: -30%;
        border-radius: 35%;
        box-shadow: 0px 0px 0px 150px rgba(255,255,255, 1);
        z-index: 24 !important;
    }

and the HTML

<section class="stage">
    <figure class="line"></figure>
</section>

Here's the fiddle of what I have thus far (also, I'm gonna need to rotate it for certain areas)

http://jsfiddle.net/speo9bfv/1/

Thanks for the help!

回答1:

If you have a plain background color, you can do this with pseudo elements :

DEMO

HTML :

<section class="stage">
    <figure class="line"></figure>
</section>

CSS :

.line {
    height: 8px;
    position:relative;
    overflow:hidden;
    z-index:1;
    top: 50px;
    left: 50px;
    width: 140px;
    -webkit-transform: rotate(38deg);
    transform: rotate(38deg);
    background:rgba(0,0,0,0.6);
}
.line:after, .line:before {
    content:'';
    position: absolute;
    left:0;
    width:100%;
    height:100%;
    border-radius: 35%;
    background:#fff;
}
.line:after{
    top:5px;
}
.line:before{
    bottom:5px;
}

回答2:

I would try using gradients to create the illusion of a pinched line.

black -> white -> black

black line

black -> white -> black

I wanted this to just be a comment, but I couldn't make new lines like I wanted.

Here's a fiddle for you: http://jsfiddle.net/qaqafc6f/

Here is a better one, with rotate applied. http://jsfiddle.net/qaqafc6f/2/

Note this does not use :before or :after, and is probably more cross-browser compatible (as long as you add the vendor prefixes).

回答3:

If you need a transparency around this shape you could use two pseudo elements with a curved border-radius and multiple box-shadows to colour in the space between them:

.line {
    height: 8px;
    position:relative;
    overflow:hidden;
    z-index:1;
    top: 50px;
    left: 50px;
    width: 140px;
    -webkit-transform: rotate(38deg);
    transform: rotate(38deg);
}
.line:after, .line:before {
    content:'';
    position: absolute;
    left:-10px;
    right:-10px;
    height:100%;
    border-radius: 50%;
    background:transparent;
    box-shadow: 0 0 1px 1px rgba(0, 0, 0, .5), 5px 0 0px 2px rgba(0, 0, 0, .5), -5px 0 0px 2px rgba(0, 0, 0, .5), 10px 0 0px 2px rgba(0, 0, 0, .5), -10px 0 0px 2px rgba(0, 0, 0, .5), 15px 0 0px 2px rgba(0, 0, 0, .5), -15px 0 1px 2px rgba(0, 0, 0, .5), 20px 0 0px 2px rgba(0, 0, 0, .5), -20px 0 0px 2px rgba(0, 0, 0, .5), 25px 0 0px 2px rgba(0, 0, 0, .5), -25px 0 0px 2px rgba(0, 0, 0, .5), 30px 0 1px 1px rgba(0, 0, 0, .5), -30px 0 1px 1px rgba(0, 0, 0, .5);
}

Or - if an inline svg datauri is acceptable - you could do something like:

.svg-stick {
    margin-top:200px;
    display:block;
    width:140px;
    height:8px;
    background: transparent url(data:image/svg+xml;
    base64, PD94bWwgdmVyc2lvbj0iM...etc...) center center no-repeat;
    background-size:100% 100%;
    -webkit-transform: rotate(38deg);
    transform: rotate(38deg);
}

Both demoed here: http://jsfiddle.net/eqaL4g5q/

来源：https://stackoverflow.com/questions/26196460/how-to-pinch-the-middle-of-a-line-in-css