样式如下：

方式一：使用图片

<template>
    <div class="main">
        <div class="win">
            <div class="title">
                <i class="icon close-icon"/>
            </div>
        </div>
    </div>
</template>
<style scoped>
.main {
    padding: 20px;
}
.win {
    width: 300px;
    height: 200px;
    background: #ccc;
    border-radius: 3px;
}
.title {
    height: 30px;
    background: mediumaquamarine;
}
.icon {
    cursor: pointer;
    float: right;
    margin: 5px;
}
.close-icon {
    content: url('~@images/close.png')
}
.close-icon:hover {
    content: url('~@images/close-hover.png')
}
</style>

方式二：使用 el-icon

<template>
    <div class="main">
        <div class="win">
            <div class="title">
                <i class="icon el-icon-close"/>
            </div>
        </div>
    </div>
</template>
<style scoped>
.main {
    padding: 20px;
}
.win {
    width: 300px;
    height: 200px;
    background: #ccc;
    border-radius: 3px;
}
.title {
    height: 30px;
    background: mediumaquamarine;
}
.icon {
    cursor: pointer;
    float: right;
    margin: 5px;
}
.icon:hover {
    color: red;
}
</style>