.title {
    margin: 0;
    text-align: center; /*设置文本水平居中*/
    overflow: hidden; /*防止内容超出容器或者产生自动换行*/
    font-size: 3em;
    color: white;
    border:1px solid red;
    overflow-x: hidden;
    overflow-y: hidden;
    background-color: #028cfd;
}

.top {
    padding: 0;
    margin: 0;
    margin: 0 auto;
    background-color: #028cfd;
    border: 1px black;
    color: white;
    width: auto;
    border:1px solid red;
    overflow-x: hidden;
    overflow-y: hidden;
}

.row-gradient {
    padding: 0;
    margin: 0;
    margin: 0 auto;
    background: linear-gradient(white, #028cfd, #028cfd, white);
    border: 1px solid red;
    color: white;
}

.row-red {
    padding: 0;
    margin: 0;
    margin: 0 auto;
    background: linear-gradient(black, red, red, black);
    border: 1px solid red;
    color: white;
}

.row-yellow {
    padding: 0;
    margin: 0;
    margin: 0 auto;
    background: linear-gradient(black, yellow, yellow, black);
    border: 1px solid red;
    color: black;
}

.english {
    font-size: 30%;
    color: white;
}

.board-background {
    padding: 0;
    margin: 0;
    margin: 0 auto;
    border: 1px solid red;
    background-color: #028cfd;
    color: white;
    overflow-x: hidden;
    overflow-y: hidden;
}