CSS重新定位包装上的元素

我认为这很简单,但事实证明这有点头疼.当用户调整浏览器大小并导致其中一个(或多个)换行到下一行时,我正试图让图像网格重新居中.

我试过给网格包装器显示：inline-block;它的父级值为text-align：center;但是当它们换行到一个新行时,这并不会使元素重新居中.帮助赞赏.

对于我想要实现的视觉picture here http://ianclarke.ca/div-reflow.png的视觉效果.

HTML：

<div class="parent-wrapper">
    <div class="child-wrapper">
        <!-- Worpress loop to load many thumnails -->
        <?PHP if(have_posts()) : ?><?PHP while(have_posts()) : the_post(); ?>
        <div class="project-thumbnail">
        <?PHP the_post_thumbnail('thumbnail'); ?>
        </div>
        <?PHP endwhile; ?>
    </div>
</div>

CSS：

.parent-wrapper
{
width:100%;
text-align: center;
}

.child-wrapper
{
display:inline-block;
}

.project-thumbnail{
float:left;
border:2px solid black;
min-width: 269px;
max-width: 269px;
}

解决方法

这是我只能用CSS思考的最佳解决方案,神奇的部分是@media查询.显然你必须做数学计算以适应你的情况.

JsFiddle Demo

body {
    margin: 0;
}
.parent-wrapper {
    margin: auto;
    width: 500px;
    padding: 5px 0;
    font-size: 0;
}
.child-wrapper {
    display: inline-block;
    width: 100px;
    font-size: 16px;
}
.child-wrapper img {
    max-width: 100%;
    height: auto;
    padding: 5px;
    vertical-align: top;
    Box-sizing: border-Box;
}
@media screen and (max-width: 499px) {
    .parent-wrapper { width: 400px; }
}
@media screen and (max-width: 399px) {
    .parent-wrapper { width: 300px; }
}
@media screen and (max-width: 299px) {
    .parent-wrapper { width: 200px; }
}
@media screen and (max-width: 199px) {
    .parent-wrapper { width: 100px; }
}

<div class="parent-wrapper">
    <div class="child-wrapper">
        <img src="//dummyimage.com/100" />
    </div>
    <div class="child-wrapper">
        <img src="//dummyimage.com/100" />
    </div>
    <div class="child-wrapper">
        <img src="//dummyimage.com/100" />
    </div>
    <div class="child-wrapper">
        <img src="//dummyimage.com/100" />
    </div>
    <div class="child-wrapper">
        <img src="//dummyimage.com/100" />
    </div>
    <div class="child-wrapper">
        <img src="//dummyimage.com/100" />
    </div>
</div>