html - Middle Div 不会位于其他 div 的中心

Question

我正在尝试创建我的 header。其中包括 Logo (左)、横幅(中)和导航栏(右)。我可以让它们彼此齐平，但无法让横幅完全位于页面中央。

横幅被推向右侧，占据屏幕大约 70% 的位置。

关于为什么会发生这种情况有什么想法吗？

#header1 {
  position: absolute;
  width: 100%;
  height: 100px;
  text-align: center;
  margin: 0px;
  padding-top: 2px;
  padding-right: 2px;
  padding-left: 2px;
  padding-bottom: 2px;
  color: white;
  font-size: 18px;
  background-image: url(content/structure/fmabannerbehind.jpg);
  background-position: center;
  font-family: Constantia, "Lucida Bright", "DejaVu Serif", Georgia, serif;
  font-style: italic;
}
#logo {
  margin-left: 0px;
  height: 100px;
  width: 200px;
  float: left;
  border-color: red;
  border-width: 3px;
  border-style: solid;
}
#logo img {
  height: 100px;
  width: auto;
}
#banner {
  position: absolute;
  height: 100px;
  width: auto;
  display: inline-block;
  margin: 0 auto;
  border-color: red;
  border-width: 3px;
  border-style: solid;
}
#banner img {
  height: 100px;
  width: auto;
}
#menu1 {
  margin-right: 0px;
  height: 100px;
  width: auto;
  float: right;
  border-color: red;
  border-width: 3px;
  border-style: solid;
}

<div id="header1">
  <div id="logo">
    <a href="http://www.fmarchived.com">
      <img src="/content/structure/logo3.jpg" alt="logo">
    </a>
  </div>
  <div id="banner">
    <a href="/">
      <img src="/content/structure/fmabanneronly.jpg" alt="banner">
    </a>
  </div>
  <div id="menu1">
    <div class="child2menu">
      <ul>
        <li><a href="/aboutus/">About Us</a>
        </li>
        <li><a href="https://www.facebook.com/fmarchived/">Facebook</a>
        </li>
        <li><a href="https://twitter.com/fmarchived">Twitter</a>
        </li>
        <li><a href="https://www.youtube.com/channel/UCOA0NFV-DuoqCRFT3YzBzRg">Youtube</a>
        </li>
      </ul>
    </div>
  </div>
</div>

Answer 1

更新

Perhaps I should have explained better, I want the banner to be center of the entire page, regardless of what the other divs are doing

然后将position:relative添加到#header1和position:absolute + display: inline-table; position:absolute; left:0; right:0; margin:auto; 到 #banner 在两个片段

选项#1 - 使用 CSS flexbox

使用 flexbox 中的 justify-content: space-between 你可以做到这一点，并大大简化你的代码

---

* {
  box-sizing: border-box;
  margin: 0
}
#header1 {
  display: flex;
  justify-content: space-between;
  position: relative
}
#header1 > div {
  border: solid red
}
img {
  vertical-align: bottom
}
#banner {
  display: inline-table;
  position: absolute;
  left: 0;
  right: 0;
  margin: auto;
}

<div id="header1">
  <div id="logo">
    <a href="http://www.fmarchived.com">
      <img src="//lorempixel.com/200/100" alt="logo">
    </a>
  </div>
  <div id="banner">
    <a href="/">
      <img src="//lorempixel.com/100/100" alt="banner">
    </a>
  </div>
  <div id="menu1">
    <div class="child2menu">
      <ul>
        <li><a href="/aboutus/">About Us</a>
        </li>
        <li><a href="https://www.facebook.com/fmarchived/">Facebook</a>
        </li>
        <li><a href="https://twitter.com/fmarchived">Twitter</a>
        </li>
        <li><a href="https://www.youtube.com/channel/UCOA0NFV-DuoqCRFT3YzBzRg">Youtube</a>
        </li>
      </ul>
    </div>
  </div>
</div>

选项#2 - 使用您当前的代码

将 position:absolute 从 #header1 更改为 relative 以删除滚动条

---

* {
  box-sizing: border-box;
  margin: 0
}
#header1 {
  position: relative;
  width: 100%;
  height: 100px;
  text-align: center;
  margin: 0;
  padding: 2px;
  color: white;
  font-size: 18px;
  background-image: url(content/structure/fmabannerbehind.jpg);
  background-position: center;
  font-family: Constantia, "Lucida Bright", "DejaVu Serif", Georgia, serif;
  font-style: italic;
}
#header1 > div {
  border: 3px solid red
}
img {
  height: 100px;
  width: auto;
  vertical-align:bottom
}
#logo {
  margin-left: 0;
  width: 200px;
  float: left;
}
#banner {
  width: auto;
  display: inline-table;
  position:absolute;
  left:0;
  right:0;
  margin:auto;

    
}
#menu1 {
  margin-right: 0px;
  float: right;
}

<div id="header1">
  <div id="logo">
    <a href="http://www.fmarchived.com">
      <img src="//lorempixel.com/100/100" alt="logo">
    </a>
  </div>
  <div id="banner">
    <a href="/">
      <img src="//lorempixel.com/100/100" alt="banner">
    </a>
  </div>
  <div id="menu1">
    <div class="child2menu">
      <ul>
        <li><a href="/aboutus/">About Us</a>
        </li>
        <li><a href="https://www.facebook.com/fmarchived/">Facebook</a>
        </li>
        <li><a href="https://twitter.com/fmarchived">Twitter</a>
        </li>
        <li><a href="https://www.youtube.com/channel/UCOA0NFV-DuoqCRFT3YzBzRg">Youtube</a>
        </li>
      </ul>
    </div>
  </div>
</div>