如何去除砖石布局右边距的多余space

How to remove the extra space on the right margin of masonry layout

使用Masonry layout library, I've created a two-column layout that you can see on codepen。在布局的右侧可以看到一个额外的 space。谁能告诉我如何摆脱它?

// external js: masonry.pkgd.js

$('.grid').masonry({
  itemSelector: '.grid-item',
  gutter: 4,
  columnWidth: '.grid-sizer',
  // percentPosition: true
});
* { box-sizing: border-box; }

body { font-family: sans-serif; }

/* ---- grid ---- */

.grid {
  background: #EEE;
  max-width: 1200px;
}

/* clearfix */
.grid:after {
  content: '';
  display: block;
  clear: both;
}

/* ---- grid-item ---- */
.grid-sizer,
.grid-item {
  width: 48%;
  height: 120px;
  float: left;
  /* vertical gutter */
  margin-bottom: 10px;
  background: #D26;
  border-radius: 5px;
}

.grid-item--height2 { height: 200px; }
.grid-item--height3 { height: 260px; }
.grid-item--height4 { height: 360px; }
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://masonry.desandro.com/masonry.pkgd.js"></script>
<h1>Masonry - gutter, margin bottom</h1>

<div class="grid">
  <div class="grid-sizer"></div>
  <div class="grid-item"></div>
  <div class="grid-item grid-item--height2"></div>
  <div class="grid-item grid-item--height3"></div>
  <div class="grid-item grid-item--height2"></div>
  <div class="grid-item"></div>
  <div class="grid-item"></div>
  <div class="grid-item"></div>
  <div class="grid-item grid-item--height2"></div>
  <div class="grid-item grid-item--height4"></div>
  <div class="grid-item"></div>
  <div class="grid-item grid-item--height2"></div>
  <div class="grid-item"></div>
  <div class="grid-item grid-item--height2"></div>
  <div class="grid-item"></div>
  <div class="grid-item"></div>
  <div class="grid-item grid-item--height2"></div>
  <div class="grid-item"></div>
  <div class="grid-item"></div>
  <div class="grid-item grid-item--height3"></div>
  <div class="grid-item grid-item--height2"></div>
  <div class="grid-item"></div>
  <div class="grid-item"></div>
  <div class="grid-item grid-item--height2"></div>
</div>

我用calc填充网格供参考

https://developer.mozilla.org/en-US/docs/Web/CSS/calc

// external js: masonry.pkgd.js

$('.grid').masonry({
  itemSelector: '.grid-item',
  gutter: 4,
  columnWidth: '.grid-sizer',
  // percentPosition: true
});
* { box-sizing: border-box; }

body { font-family: sans-serif; }

/* ---- grid ---- */

.grid {
  background: #EEE;
  max-width: 1200px;
}

/* clearfix */
.grid:after {
  content: '';
  display: block;
  clear: both;
}

/* ---- grid-item ---- */
.grid-sizer,
.grid-item {
  width: calc(50% - 2px);
  height: 120px;
  float: left;
  /* vertical gutter */
  margin-bottom: 10px;
  background: #D26;
  border-radius: 5px;
}

.grid-item--height2 { height: 200px; }
.grid-item--height3 { height: 260px; }
.grid-item--height4 { height: 360px; }
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="https://masonry.desandro.com/masonry.pkgd.js"></script>
<h1>Masonry - gutter, margin bottom</h1>

<div class="grid">
  <div class="grid-sizer"></div>
  <div class="grid-item"></div>
  <div class="grid-item grid-item--height2"></div>
  <div class="grid-item grid-item--height3"></div>
  <div class="grid-item grid-item--height2"></div>
  <div class="grid-item"></div>
  <div class="grid-item"></div>
  <div class="grid-item"></div>
  <div class="grid-item grid-item--height2"></div>
  <div class="grid-item grid-item--height4"></div>
  <div class="grid-item"></div>
  <div class="grid-item grid-item--height2"></div>
  <div class="grid-item"></div>
  <div class="grid-item grid-item--height2"></div>
  <div class="grid-item"></div>
  <div class="grid-item"></div>
  <div class="grid-item grid-item--height2"></div>
  <div class="grid-item"></div>
  <div class="grid-item"></div>
  <div class="grid-item grid-item--height3"></div>
  <div class="grid-item grid-item--height2"></div>
  <div class="grid-item"></div>
  <div class="grid-item"></div>
  <div class="grid-item grid-item--height2"></div>
</div>