为什么背景图片无法填充整个div

Question

我有以下代码，该代码在DIV内显示一个SPAN ，然后在其下显示另一个文本的另一个DIV 。 我遇到的问题是，当我调整浏览器的大小时，文本和背景图像变得不完整。

这是图像如何未填充DIV的屏幕截图：

另外，当我调整大小时，文本都不合适了：

这是HTML：

<div id="subpageHeaderImageSection">
    <div id="subpageHeaderLeft">
        <!--<img src="theImages/wcu.png" style="z-index: 5; position: absolute; bottom: 0; left: 10%; width: 194px; width: 185px;"  />
        <span id="quoteText" style="z-index: 4;">
            We Have the Finest Physicians, Staff, and Systems for the Finest Healthcare
        </span>-->
    </div>
</div>
<div id="subpageFooter">
    <div id="subpageFooterLeft">
        <div style="z-index: 15; position: absolute; left: 0; padding-left: 20px; padding-top: 10px; font-weight: bold; color: #0000CC;">
            State-Of-The-Art-Technology
        </div>
        <div style="z-index: 14; position: absolute; left: 0; padding-left: 40px; padding-top: 35px; padding-right: 8px; font-weight: normal; color: #000000;">
            Our state-of-the-art technology ensures that we provide the finest healthcare. Our practice continuously invests in systems and equipment so that physicians can diagnose problems in the most accurate and efficient manner possible.
        </div>
        <div style="position: absolute; width: 90%; padding-top: 90px; padding-left: 5%; padding-right: 5%;"><hr /></div>
        <div style="z-index: 13; position: absolute; left: 0; padding-left: 20px; padding-top: 110px; font-weight: bold; color: #0000CC;">
            Advanced Electronic Medical Records
        </div>
        <div style="z-index: 12; position: absolute; left: 0; padding-left: 40px; padding-top: 135px; padding-right: 8px; font-weight: normal; color: #000000;">
            Our advanced electronic medical record improves patient care and gives physicians all of the important patient information they need in one place.
        </div>
        <div style="position: absolute; width: 90%; padding-top: 175px; padding-left: 5%; padding-right: 5%;"><hr /></div>
        <div style="z-index: 11; position: absolute; left: 0; padding-left: 20px; padding-top: 200px; font-weight: bold; color: #0000CC;">
            Premier Radiology Services
        </div>
        <div style="z-index: 10; position: absolute; left: 0; padding-left: 40px; padding-top: 225px; padding-right: 8px; font-weight: normal; color: #000000;">
            Filmless radiology capabilities provide rapid results and allow physicians to view images on an office computer screen within minutes. Our premier radiology services include MRI, CT scan, ultrasonography, nuclear medicine, bone densitometry and mammography. We offer computer-aided diagnosis (CAD), which is a tool to assist the radiologist in more accurately diagnosing breast disease.
        </div>
        <div style="position: absolute; width: 90%; padding-top: 310px; padding-left: 5%; padding-right: 5%;"><hr /></div>
        <div style="z-index: 9; position: absolute; left: 0; padding-left: 20px; padding-top: 335px; font-weight: bold; color: #0000CC;">
            Our Employees Make MyMed a Special Place
        </div>
        <div style="z-index: 8; position: absolute; left: 0; padding-left: 40px; padding-top: 360px; padding-right: 8px; font-weight: normal; color: #000000;">
            MyMed values each of our employees’ experience, diversity and dedication. Ideas and backgrounds that our employees bring to our company enable us to be more effective in anticipating and exceeding our patients’ needs and expectations. <a class="blueLinks" href="http://www.mymed.com/talented_people.aspx">Click here</a> for the opportunity to meet some of the employees who greatly contribute to our success.
        </div>
        <div style="position: absolute; width: 90%; padding-top: 430px; padding-left: 5%; padding-right: 5%;"><hr /></div>
        <div style="z-index: 7; position: absolute; left: 0; padding-left: 20px; padding-top: 455px; font-weight: bold; color: #0000CC;">
            Wide Range Of Insurances
        </div>
        <div style="z-index: 6; position: absolute; left: 0; padding-left: 40px; padding-top: 480px; padding-right: 8px; font-weight: normal; color: #000000;">
            A big advantage to using WESTMED Medical Group is the <a class="blueLinks" href="http://www.mymed.com/participating_insurance.aspx?id=473">wide range of insurance coverage</a> accepted. This means you should be able to keep your doctors even if you find you have to change insurance plans. We care equally about every patient regardless of the insurance provider.
        </div>
    </div>
    <div id="subpageFooterRight">
    </div>
</div>

这是CSS：

#subpageHeaderImageSection {
    position: relative;
    top: 0;
    width: 100%;
    height: 450px;
}
#subpageHeaderLeft {
    position: absolute;
    left: 0;
    float: left;
    width: 100%;
    height: 100%;
    background: url('../theImages/subpageHeaderImage.png') no-repeat;
    background-size: 100%;
}
#subpageFooter {
    position: relative;
    width: 100%;
    height: 555px;
    background: url('../theImages/bg_80_w.png');
    box-shadow: 0 0 10px #FFFFFF;
}
#subpageFooterRight {
    position: absolute;
    right: 0;
    width: 40%;
    height: 100%;
    float: right;
    background-color: #000000;
}
#subpageFooterLeft {
    position: absolute;
    left: 0;
    float: left;
    width: 60%;
    height: 100%;
}
#quoteText {
    position: absolute;
    bottom: 30%;
    left: 40%;
    overflow: hidden;
    font-family: 'daysregular';
    font-size: 30pt;
}

我真的希望提供两点帮助：

1. 无论我如何调整大小，如何确保标题上的背景图像始终充满DIV？
2. 如何确保文本不会像第二个图像那样彼此重叠？

Answer 1

使用background-size:cover ，它将填充。

Answer 2

使用background-size: 100% 100%完全填充（可能会拉伸），否则，请使用background-size: cover如@Andras所说