/* 清除内、外间距 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* 添加背景图片 */
body{
    background: url(../img/background.png) no-repeat center top;
    background-size: cover;
    background-attachment: fixed;
    user-select: none;
}

/* 背景装饰元素 */
.background_element01{
    width: 10%;
    position: absolute;
    top: 150px;
    left: 50px;
    pointer-events: none;
}

.background_element02{
    width: 25%;
    position: absolute;
    right: 0;
    pointer-events: none;
}

.background_element03{
    width: 23%;
    position: absolute;
    right: 0;
    bottom: 0;
    pointer-events: none;
}

/* 标题、LOGO */
.titleBox{
    width: 100%;
    height: 100px;
    padding: 20px;
    margin-bottom: 20px;
}

.titleBox>h2{
    color: darkred;
}

.titleBox>h1{
    color: darkred;
    text-align: center;
    font-size: 40px;
}

/* 主要内容 */
.main{
    width: 65%;
    background: darkred;
    padding: 10px;
    margin: 0 auto;
    border-radius: 20px;
    box-shadow: 3px 3px 0 goldenrod;
}

.main .title{
    color: white;
    text-align: center;
    line-height: 55px;
}

.main>p{
    font-size: 10px;
    color: white;
    text-align: center;
    letter-spacing: 2px;
}

.topicBox{
    width: 90%;
    height: 70%;
    margin: 10px auto;
    font-size: 20px;
    font-weight: bold;
    text-align: left;
    background: white;
    border-radius: 10px;
    padding: 20px;
    line-height: 40px;
    box-shadow: 3px 3px 0 goldenrod;
}

.topicBox>div{
    width: 100%;
    height: 200px;
}

.topicBox>div:nth-child(1){
    border-bottom: 3px solid darkred;
    margin-bottom: 20px;
}

/* 按钮样式 */
.buttonBox{
    width: 100%;
    text-align: center;
}

.buttonBox input{
    width: 200px;
    height: 50px;
    margin: 10px 20px;
    font-size: 28px;
    font-weight: bold;
    border-radius: 10px;
    outline: none;
    box-shadow: 3px 3px 0 rosybrown;
    color: darkred;
    border: 0px;
}

/* 答案样式 */
.answer span{
    margin-right: 30px;
    font-size: 23px;
}

/* 正确答案样式 */
.correct_answer{
    background: darkred;
    color: white;
}