#header-container .nav{
   background: transparent;
   transition: all 0.5s ease;
}

#header-container .nav:hover {
  background: url("/images/nav-bg1.jpg") no-repeat center / cover !important;
}

.nav .menu .menu-item {
    color: var(--color-primary-1);
}

#header-container .nav:hover .menu .menu-item{
  color: var(--color-primary-4);
}

#header-container .nav .menu .split-line {
    color: transparent;
}

#header-container .nav:hover .menu .split-line{
    color: var(--color-primary-9);
}

.main-container {
    box-sizing: border-box;
    width: 100vw;
    height: auto;
}

.about-bg {
    box-sizing: border-box;
    width: 100%;
    height: 100vh;
    position: relative;
}

.about-bg #about-video {
    width: 100%;
    height: 100%;
    object-fit: cover;
    position: absolute;
    top: 0;
    left: 0;
    z-index: -1;
}

.about-bg .bg-mask {
    // 蒙层
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, .5);
    position: relative;
    display: flex;
    justify-content: center;
    align-items: center;
    flex-direction: column;
}

.about-bg .bg-mask .title{
    font-size: 3.5rem;
    color: var(--color-white);
    margin-bottom:1.875rem;
    opacity: 0.9;
    font-weight: 600;
}

.about-bg .bg-mask .desc{
    font-size: 1.1rem;
    color: var(--color-white);
    line-height: 2;
    opacity: 0.9;
}


.about-bg .mask {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.9);
    z-index: 9999;
    display: none;
}

/* 播放按钮样式 */
.about-bg  #playBtn {
    width: 3.75rem;
    height: 3.75rem;
    background: transparent;
    border-radius: 50%;
    position: absolute;
    bottom: 22%;
    left: 50%;
    transform: translate(-50%, -50%);
    cursor: pointer;
    transition: all 0.3s ease;
    backdrop-filter: blur(5px);
    border: 2px solid rgba(255, 255, 255, 0.1);
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.2);
}

.about-bg  #playBtn::after {
    content: '';
    position: absolute;
    left: 52%;
    top: 50%;
    transform: translate(-40%, -50%);
    border-left: 20px solid rgba(255, 255, 255, 0.3);
    border-top: 12px solid transparent;
    border-bottom: 12px solid transparent;
    transition: all 0.3s ease;
}

.about-bg  #playBtn:hover {
    background: rgba(128, 128, 128, 0.2);
    box-shadow: 0 0 30px rgba(0, 0, 0, 0.3);
}

.about-bg #playBtn:hover::after {
    border-left-color: rgba(255, 255, 255, .9);
}

/* 核心容器 */
.about-container {
    width: 80vw;
    height: auto;
    margin: 0 auto;
    border-top: 1px solid transparent;
    position: relative;
    transition: transform 0.5s ease-out;
}

.about-container.move-up {
    transform: translateY(-11.25rem);
}

.about-container .part {
    width: 100%;
    height: 31.25rem;
    margin-bottom: 5.5rem;
    border-radius: 5px;
    z-index: -1;
}

.about-container .part .title {
    font-size: 3rem;
    font-weight: bold;
    color: #333;
    text-align: center;
    margin-top: 6.25rem;
}

.part1 {
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    align-items: space-between;
    background-color: #fff;
}

.part1 .card-box{
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
}

.part1 .card-box .card{
    box-sizing: border-box;
    width: 18.125rem;
    height: 13.75rem;
    border-radius: 10px;
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.2);
    transition: all 0.3s ease;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 1.875rem;
    transition: transform .3s ease; /* 平滑过渡效果 */
    padding: .625rem; /* 增加内边距 */
    font-family: '微软雅黑';
}

.part1 .card-box .card:hover {
    background: linear-gradient(135deg,rgb(236, 127, 131), #c00000);
    box-shadow: 0 0 20px rgba(192, 0, 0, 0.2);
    color: #fff;
    transform: scale(1.05);
    /* transform: rotateY(180deg); */
}

.part1 .card-box .card .mark .data{
    width: 4.3125rem;
    height: 4.3125rem;
}

.part1 .card-box .card:hover .mark .data{
    color: #fff;
    /* transform: rotateY(180deg); */
}

.part1 .card-box .card:hover .desc {
    color: #fff;
    /* transform: rotateY(180deg); */
}

.part1 .card-box .card .mark{
   font-size: 1rem;
   font-weight: bold;
   display: inline-block;
   vertical-align: bottom;
}

.part1 .card-box .card .mark .data{
  font-size: 3.4375rem;
  vertical-align: bottom;
  display: inline-block;
  line-height: 1;
  color: #c00000;
}


.part2 {
    display: flex;
    justify-content: flex-start;
    align-items: center;
    overflow: hidden;
    position: relative;
}

.part2::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: url('/images/about/1.jpg');
    background-size: cover;
    background-position: center;
    z-index: -1;
    transition: transform 0.5s ease;
}

.part2:hover::before {
    transform: scale(1.1);
}


.part2 .mask {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    z-index: -1;
}

.part2 .content {
    width: 90%;
    height: auto;
    box-sizing: border-box;
    text-align: justify;
    color: #fff;
    margin-left: 5rem;
}

.part2 .content h1 {
    font-size: 3rem;
    color: #fff;
    margin-bottom: 1.875rem;
    font-weight: bold;
    opacity: 0.9;
}

.part2 .content div {
    font-size: 1rem;
    line-height: 1.5rem;
    opacity: 0.9;
}

.part2 .content div:first-of-type {
    margin-bottom: 1.875rem;
}

.about-container .part.part3 {
    height: 35rem;
}

.part3 {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: -80px !important;
}

.part3 .l {
    width: 47%;
    height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
}


.part3 .l .info{
    height: auto;
}


.part3 .l .info h1{
    font-size: 3rem;
    color: #333;
    font-weight: bold;
}


.part3 .l .info div{
    color: #333;
    text-align: justify;
    line-height: 1.5;
    margin-top: 1rem;
    margin-bottom: 1rem;
}

.part3 .l .pic1 {
    position: relative;
    width: 100%;
    height: 100%;
    overflow: hidden;
    border-radius: 5px;
}

.part3 .l .pic1::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: url('/images/about/2.png');
    background-size: cover;
    background-position: center;
    z-index: -1;
    transition: transform 0.5s ease;
}

.part3 .l .pic1:hover::before {
    transform: scale(1.1);
}

.part3 .r {
    width: 47%;
    height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
}

.part3 .r .pic2 {
    position: relative;
    width: 100%;
    flex: 1;
    overflow: hidden;
    border-radius: 5px;
}

.part3 .r .pic2::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-image: url('/images/about/3.jpg');
    background-size: cover;
    background-position: center;
    z-index: -1;
    transition: transform 0.5s ease;
}

.part3 .r .pic2:hover::before {
    transform: scale(1.1);
}

.part3 .r .info {
    color: #333;
    margin-top: 1.5rem;
    text-align: justify;
}

/* 向下滚动 */
.scroll-prompt {
    position: fixed;
    bottom: 5rem;;
    right: 1rem;
    display: flex;
    flex-direction: column;
    align-items: center;
    cursor: pointer;
    opacity: 1;
    transition: opacity 0.3s;
    z-index: 1000;
    color: var(--color-primary-7);
}

.scroll-prompt:hover {
    transition: all 0.5s;
    color: var(--color-primary-4);
}

.vertical-text {
    writing-mode: vertical-lr;
    font-size: 0.875rem;
    letter-spacing: 0.375rem;
    margin-bottom: 1rem;
}

.line-container {
    position: relative;
    height: 3.125rem;
    width: 1px;
}

.line-background {
    position: absolute;
    left: 0;
    top: 0;
    width: 1px;
    height: 100%;
    background: var(--color-primary-7);
}

.line-moving {
    position: absolute;
    left: -0.125rem;
    width: 0.375rem;
    height: 1.125rem;
    animation: slide 2s infinite;
    border-radius: 1px;
}

@keyframes slide {
    0% {
        top: -15%;
        opacity: 0;
        background:var(--color-primary-1);
    }
    15% {
        opacity: 0.8;
    }
    50% {
        opacity: 1;
        background:var(--color-primary-6);
    }
    85% {
        opacity: 0.8;
    }
    100% {
        top: 70%;
        opacity: 0;
        background:var(--color-primary-11);
    }
}