CSS:

.content {
    width: 80%;
    margin: 10px auto;
}

.hide_box {
    z-index: 999;
    filter: alpha(opacity=50);
    background: #666;
    opacity: 0.5;
    -moz-opacity: 0.5;
    left: 0;
    top: 0;
    height: 99%;
    width: 100%;
    position: fixed;
    display: none;
}

.shang_box {
    width: 540px;
    height: 540px;
    padding: 10px;
    background-color: #fff;
    border-radius: 10px;
    position: fixed;
    z-index: 1000;
    left: 50%;
    top: 50%;
    margin-left: -280px;
    margin-top: -280px;
    border: 1px dotted #dedede;
    display: none;
}

    .shang_box img {
        border: none;
        border-width: 0;
    }

.dashang {
    display: block;
    width: 100px;
    margin: 5px auto;
    height: 25px;
    line-height: 25px;
    padding: 10px;
    background-color: #E74851;
    color: #fff;
    text-align: center;
    text-decoration: none;
    border-radius: 10px;
    font-weight: bold;
    font-size: 16px;
    transition: all 0.3s;
}

    .dashang:hover {
        opacity: 0.8;
        padding: 15px;
        font-size: 18px;
    }

.shang_close {
    float: right;
    display: inline-block;
}

.shang_logo {
    display: block;
    text-align: center;
    margin: 20px auto;
}

.shang_tit {
    width: 100%;
    height: 75px;
    text-align: center;
    line-height: 66px;
    color: #a3a3a3;
    font-size: 16px;
    background: url('/images/cy-reward-title-bg.jpg');
    font-family: 'Microsoft YaHei';
    margin-top: 7px;
    margin-right: 2px;
}

    .shang_tit p {
        color: #a3a3a3;
        text-align: center;
        font-size: 16px;
    }

.shang_payimg {
    width: 140px;
    padding: 10px;
    border: 6px solid #EA5F00;
    margin: 0 auto;
    border-radius: 3px;
    height: 140px;
}

    .shang_payimg img {
        display: block;
        text-align: center;
        width: 140px;
        height: 140px;
    }

.pay_explain {
    text-align: center;
    margin: 10px auto;
    font-size: 12px;
    color: #545454;
}

.radiobox {
    width: 16px;
    height: 16px;
    background: url('/images/radio2.jpg');
    display: block;
    float: left;
    margin-top: 5px;
    margin-right: 14px;
}

.checked .radiobox {
    background: url('/images/radio1.jpg');
}

.shang_payselect {
    text-align: center;
    margin: 0 auto;
    margin-top: 40px;
    cursor: pointer;
    height: 60px;
    width: 280px;
}

    .shang_payselect .pay_item {
        display: inline-block;
        margin-right: 10px;
        float: left;
    }

.shang_info {
    clear: both;
}

    .shang_info p, .shang_info a {
        color: #C3C3C3;
        text-align: center;
        font-size: 12px;
        text-decoration: none;
        line-height: 2em;
    }

JavaScript:

<script>
    $(function () {
        $(".pay_item").click(function () {
            $(this).addClass('checked').siblings('.pay_item').removeClass('checked');
            var dataid = $(this).attr('data-id');
            $(".shang_payimg img").attr("src", "/images/" + dataid + "img.png");
            $("#shang_pay_txt").text(dataid == "alipay" ? "支付宝" : "微信");
        });
    });
    function dashangToggle() {
        $(".hide_box").fadeToggle();
        $(".shang_box").fadeToggle();
    }
</script>

HTML:

<div class="recommend-box">
    <div class="recommend-box-item">
        <div class="content">
            <p><a href="javascript:void(0)" onclick="dashangToggle()" class="dashang" title="打赏，支持一下">打赏</a></p>
            <div class="hide_box"></div>
            <div class="shang_box">
                <a class="shang_close" href="javascript:void(0)" onclick="dashangToggle()" title="关闭"><img src="~/images/close.jpg" alt="取消" /></a>

                <div class="shang_tit">
                    <p>感谢您的支持，我会继续努力的!</p>
                </div>
                <div class="shang_payimg">
                    <img src="~/images/alipayimg.png" alt="扫码支持" title="扫一扫" />
                </div>
                <div class="pay_explain">扫码打赏，你说多少就多少</div>
                <div class="shang_payselect">
                    <div class="pay_item checked" data-id="alipay">
                        <span class="radiobox"></span>
                        <span class="pay_logo"><img src="~/images/alipay.jpg" alt="支付宝" /></span>
                    </div>
                    <div class="pay_item" data-id="wechat">
                        <span class="radiobox"></span>
                        <span class="pay_logo"><img src="~/images/wechat.jpg" alt="微信" /></span>
                    </div>
                </div>
                <div class="shang_info">
                    <p>打开<span id="shang_pay_txt">支付宝</span>扫一扫，即可进行扫码打赏哦</p>
                    <p>Powered by <a href="https://www.v2know.com" target="_blank" title="EKsumic">v2know.com</a>，学的不仅是技术，更是梦想！！！</p>
                </div>
            </div>
        </div>
    </div>
</div>

关于CSS：

• 图片替换总数为3张，分别为引号、radio1、radio2图片
• .content类可能与你的CSS冲突，有必要修改你的样式

关于JavaScript:

• 无需改动

关于HTML：

• alipay.jpg\wechat.jpg\alipayimg.png\wechatimg.png\close.jpg 要准备好
• 注意裁剪二维码，大小为140*140px

这份代码的研究价值：

• hover放大动画
• 点击白色半透明背景动画
• 淡入淡出动画
• 无锁定当前活动窗口

英文版→点击

参考文档：

https://www.runoob.com/w3cnote/website-reward-button.html