@charset "utf-8";
/* CSS Document */

/* 基础样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Microsoft YaHei', Arial, sans-serif;
    font-family: 微软雅黑;
}

ul, li, ol, a {
    text-decoration: none;
    list-style: none;
}

/* 根元素默认字体（适配中等屏幕） */
html {
    font-size: 16px; /* 1rem = 16px */
}

/* 小屏幕（手机）：缩小根元素字体，所有rem字体同步缩小 */
@media screen and (max-width: 768px) {
    html {
        font-size: 14px; /* 1rem = 14px */
    }
}

/* 大屏幕（电脑）：放大根元素字体，所有rem字体同步放大 */
@media screen and (min-width: 1200px) {
    html {
        font-size: 18px; /* 1rem = 18px */
    }
}


a {
    text-decoration: none;
    list-style: none;
    text-decoration: none;
}

.dbjbox {
    width: 100%;
    height: 100vh;
    background: url(../images/ydy_dbj.jpg) no-repeat center bottom;
    background-size: cover;
    display: flex;
    flex-flow: column nowrap;
    align-items: center;
    position: relative;
}

header {
    width: 100%;
}

.head {
    width: 100%;
    max-width: 70%;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    position: relative;
}

.logo {
    width: 28%;
    margin-top: 30px;
    max-width: 268px;
    max-height: 202px;
    min-width: 100px;
}

.logo img {
    width: 100%;
}

.dh {
    width: 50%;
    display: flex;
    flex-flow: row nowrap;
    justify-content: space-between;
    margin-top: 60px;
}

.ydy_xtb {
    width: 10%;
    height: 130px;
    min-width: 60px;
    margin: 0 2%;
    display: flex;
    flex-flow: column;
    justify-content: center;
    align-items: center;
}

.ydy_xtb span {
    width: 100%;
    max-width: 62px;
    height: 100%;
    min-height: 62px;
    margin-bottom: 5px;
    text-align: center;
}

.ydy_xtb span img {
    width: 100%;
}

.ydy_xtb p {
    color: #ffffff;
    font-size: 1.125rem;
    line-height: 45px;
    font-family: "微软雅黑";
    letter-spacing: 1px;
    font-weight: bold;
    text-align: center;
}

.ydy_xtb p a {
    color: #FFF
}

.ydy_ewm {
    max-height: 120px;
    max-width: 120px;
    align-items: center;
    margin-top: 30px;
}

.ydy_ewm img {
    width: 100%;
}


/*4张图片*/

.ydy_tbnav {
    width: 100%;
    max-width: 60%;
    display: flex;
    justify-content: space-between;
    margin-top: 145px;
}

.ydy_tbnav_li {
    width: 100%;
    height: auto;
    margin: 2% 2%;
    max-width: 193px;
    max-height: 397px;
    position: relative;
}

.ydy_tbnav_li img {
    width: 100%;
    height: 100%;
    max-width: 193px;
    max-height: 397px;
}

.ydy_tbnav_li_img {
    width: 85%;
    max-width: 102px;
    /* 开启3D空间，让旋转更有立体感 */
    perspective: 1000px;
    height: auto;
    display: flex;
    justify-content: center;
    align-items: center;
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
}

.ydy_tbnav_li_img a {
    display: flex;
    justify-content: center;
    align-items: center;
}

.ydy_tbnav_li_img a img {
    width: 100%;
    transform-style: preserve-3d;
    /* 应用旋转动画：动画名 时长 匀速 无限循环 */
    animation: verticalRotate 8s linear infinite;
}

/* 定义垂直旋转动画关键帧 */
@keyframes verticalRotate {
    0% {
        /* 初始状态：旋转0度 */
        transform: rotateY(0deg);
    }
    100% {
        /* 结束状态：旋转360度（一圈） */
        transform: rotateY(360deg);
    }
}

/* 可选：hover暂停动画，提升交互体验 */
.img-container:hover .rotate-img {
    animation-play-state: paused;
}

.ydy_tbnav_li:nth-child(even) {
    margin-top: 9%;
}


@media screen and (max-width: 1200px) {
    .dh {
        width: 100%;
        display: flex;
        justify-content: space-between;
        flex-flow: row wrap;
        position: absolute;
        top: 180px;
        left: 50%;
        transform: translateX(-50%);
    }
}


@media screen and (max-width: 1024px) {
    .ydy_ewm img {
        max-width: 100px;
    }

    .dh {
        top: 150px;
        position: absolute;
    }
}

@media screen and (max-width: 920px) {
    .dh {
        width: 100%;
        position: absolute;
        top: 100px;
    }

    .ydy_tbnav_li_title {
        font-size: 1.25rem;
    }

    .ydy_xtb a p {
        font-size: 1.125rem;
        min-width: 75px;
    }

    .ydy_ewm img {
        max-width: 80px;
    }
}

@media screen and (max-width: 768px) {
    .ydy_tbnav {
        margin-top: 241px;
        width: 85%;
    }
}

@media screen and (max-width: 576px) {
    .ydy_tbnav {
        margin-top: 300px;
    }
}