/* 引入字体 */
/* DIN-Bold字体 */
@font-face {
    font-family: 'DIN-Bold';
    src: url('../fonts/DIN-Bold.otf') format('opentype');
    font-weight: bold;
    font-style: normal;
}

/* 引入Alibaba PuHuiTi字体 */
@font-face {
    font-family: 'Alibaba PuHuiTi';
    src: url('../fonts/AlibabaPuHuiTi-3-55-Regular.woff2') format('woff2'),
         url('../fonts/AlibabaPuHuiTi-3-55-Regular.woff') format('woff'),
         url('../fonts/AlibabaPuHuiTi-3-55-Regular.otf') format('opentype');
    font-weight: normal;
    font-style: normal;
}

@font-face {
    font-family: 'Alibaba PuHuiTi';
    src: url('../fonts/AlibabaPuHuiTi-3-75-SemiBold.woff2') format('woff2'),
         url('../fonts/AlibabaPuHuiTi-3-75-SemiBold.woff') format('woff'),
         url('../fonts/AlibabaPuHuiTi-3-75-SemiBold.otf') format('opentype');
    font-weight: 600;
    font-style: normal;
}
@font-face {
    font-family: 'Alibaba PuHuiTi L';
    src: url('../fonts/AlibabaPuHuiTi-3-45-Light.woff2') format('woff2'),
         url('../fonts/AlibabaPuHuiTi-3-45-Light.woff') format('woff'),
         url('../fonts/AlibabaPuHuiTi-3-45-Light.otf') format('opentype');

    font-style: normal;
}

/* 全局样式重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    margin: 0;
    padding: 0;
    width: 100%;
    overflow-x: hidden;
}

/* 全屏视频section */
.fullscreen-video-section {
    position: relative;
    width: 100vw;
    min-height: 100vh;
    height: auto;
    overflow: hidden;
    margin: 0;
    padding: 0;
}

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

/* 科技冬奥section */
.tech-winter-section {
    position: relative;
    background: url('../images/gjss3.jpg') no-repeat top center;
    background-size: 100% auto;
    background-color: #111111;
    min-height: 100vh;
    height: auto;
    width: 100vw;
    margin: 0;
    padding: 0;
    overflow: hidden;
}

.tech-winter-container {
    max-width: 1920px;
    margin: 0 auto;
    padding: 100px 300px;
}

.tech-winter-content {
    display: flex;
    height: 550px;
    align-items: flex-start;
}

.tech-winter-left {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
}

.tech-winter-image {
    max-width: 40%;
    max-height: 40%;
    object-fit: contain;
    margin-top: 500px;
}

.tech-winter-right {
    flex: 1;
    padding-left: 50px;
    margin-top: 200px;
}

.tech-winter-logo {
    max-width: 20%;
    margin-top: 0;
    margin-bottom: 30px;
}

.tech-winter-title {
    font-family: 'Alibaba PuHuiTi L';
    font-size: 50px;
    font-weight: 400;
    color: white;
    line-height: 1.2;
    letter-spacing: 8px;
    margin-bottom: 40px;
}

.tech-winter-description {
    width: 650px;
    font-family: 'Alibaba PuHuiTi';
    font-weight: 300;
    font-size: 20px;
    line-height: 3.0;
    letter-spacing: 2px;
    color: white;

}

/* 图片画廊 */
.tech-winter-gallery-container {
    width: 70%;
    margin-left: auto;
    margin-top: 200px;
    margin-bottom: 7px;
    overflow: hidden;
    padding-right: 100px;
}

.tech-winter-gallery {
    display: flex;
    align-items: center;
    gap: 15px;
    margin-top: 100px;
    animation: scrollLeft 15s linear infinite;
    white-space: nowrap;
}

.tech-winter-gallery:hover {
    animation-play-state: paused;
}

@keyframes scrollLeft {
    0% {
        transform: translateX(0);
    }
    100% {
        transform: translateX(-50%);
    }
}

.gallery-item {
    width: auto;
    height: 200px;
    max-width: 150px;
    object-fit: contain;
    cursor: pointer;
    transition: transform 0.3s ease;
}

.gallery-item:nth-child(6),
.gallery-item:nth-child(12) {
    height: 200px;
    max-width: 300px;
}

.gallery-item:hover {
    transform: scale(1.1);
}

/* 第三个section */
.third-section {
    height: auto;
    min-height: 100vh;
    background: url('../images/gjss4.jpg') no-repeat top center;
    background-size: 100% auto;
    background-color: #111111;
    width: 100vw;
    margin: 0;
    padding: 0;
    overflow: hidden;
    position: relative;
}

.third-section-content {
    position: absolute;
    right: 300px;
    width: 600px;
    text-align: right;
}

.third-section-text {
    display: flex;
    flex-direction: column;
    align-items: flex-end;
    text-align: right;
    margin-top: 240px;
}

.left-aligned-content {
    text-align: left;
    align-self: flex-start;
}

.third-section-line1 {
    font-family: 'Alibaba PuHuiTi L';
    font-size: 45px;
    font-weight: 600;
    color: black;
    letter-spacing: 10px;
    line-height: 1.2;
    margin-bottom: 20px;
}

.third-section-line2 {
    font-family: 'Alibaba PuHuiTi L';
    font-size: 45px;
    font-weight: 600;
    color: black;
    letter-spacing: 10px;
    line-height: 1.2;
    margin-bottom: 50px;
}

.third-section-line3 {
    font-family: 'Alibaba PuHuiTi L';
    font-size: 20px;
    font-weight: 400;
    color: black;
    letter-spacing: 3px;
    line-height: 1.2;
}

.year-text {
    font-family: 'DIN-Bold';
}

/* 手风琴容器样式 */
.accordion-container {
    width: 80vw;
    max-width: 1400px;
    height: 650px;
    margin: 750px auto 0;
    display: flex;
    justify-content: center;
    gap: 2px;
    padding: 0 2px;
    box-sizing: border-box;
}

/* 手风琴项样式 */
.accordion-item {
    flex: 0 0 130px;
    position: relative;
    overflow: hidden;
    border-radius: 8px;
    transition: flex 0.5s ease;
    cursor: pointer;
    background-color: transparent;
}

/* 激活状态 */
.accordion-item.active {
    flex: 0 0 1135px;
}

/* 手风琴头部 */
.accordion-header {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1;
    transition: opacity 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

.accordion-item.active .accordion-header {
    opacity: 0;
}

/* 树状图片 */
.tree-image {
    width: 100%;
    height: 100%;
    object-fit: contain;
}

/* 手风琴内容 */
.accordion-content {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 0;
    opacity: 0;
    transition: opacity 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

.accordion-item.active .accordion-content {
    opacity: 1;
}

/* 焦点图片 */
.focus-image {
    width: auto;
    height: 100%;
    max-width: 100%;
    object-fit: contain;
    margin: 0 auto;
    display: block;
}

/* 第三个section描述 */
.third-section-description {
    width: 500px;
    margin-right: 300px;
    margin-left: auto;
    margin-top: 50px;
      margin-bottom: 39px;
}

.left-aligned-text {
    text-align: left;
    font-family: 'Alibaba PuHuiTi L';
    font-weight: 300;
    font-size: 17px;
    color: black;
    letter-spacing: 2px;
    line-height: 2.5;
    margin: 0;
}

/* 第四个section */
.fourth-section {
    height: auto;
    min-height: 100vh;
    background: url('../images/gjss5.jpg') no-repeat top center;
    background-size: 100% auto;
    background-color: #111111;
    width: 100vw;
    margin: 0;
    padding: 0;
    overflow: hidden;
}

/* 第四个section内容 */
.fourth-section-content {
    display: flex;
    width: 70%;
    margin: 150px auto 0;
}

/* 第四个section左侧 */
.fourth-section-left {
    flex: 1;
    margin-left: 100px;
    margin-top: 50px;
}

/* 第四个section标题 */
.fourth-section-title {
    font-family: 'Alibaba PuHuiTi L';
    font-size:70px;
    font-weight: 300;
    letter-spacing: 13px;
    line-height: 1.2;
    margin: 0;
    color: #111111;
}

/* 年份字体 */
.fourth-section-title .year {
    font-family: 'DINOT Bold';
    font-weight: bold;
}

/* 第四个section右侧 */
.fourth-section-right {
    flex: 1;
    display: flex;
    flex-direction: column;
}

/* 第四个section图片 */
.fourth-section-image {
    width: 100%;
    height: auto;
}

/* 第四个section描述 */
.fourth-section-description {
    text-align: right;
    margin-right: 100px;
    margin-top: 20px;
    height: 520px;
}

/* 第四个section文字 */
.fourth-section-text {
    text-align: left;
    font-family: 'Alibaba PuHuiTi L';
    font-weight: 200;
    font-size: 16px;
    color: #111111;
    letter-spacing: 2px;
    line-height: 2.2;
    margin: 0;
    margin-left: 100px;
}

/* 响应式设计 */
@media (max-width: 1920px) {
    .tech-winter-container {
        padding: 0 200px;
    }
    
    .tech-winter-image {
        margin-top: 470px;
    }
    
    .tech-winter-right {
        margin-top: 190px;
    }
    
    .tech-winter-logo {
        max-width: 18%; 
    }
    
    .tech-winter-title {
        font-size: 40px;
         font-family: 'Alibaba PuHuiTi R';
            line-height: 1.3;
            font-weight: 600;
    }
    
    .tech-winter-description {
        font-family: 'Alibaba PuHuiTi L';
        font-size: 18px;
        width: 550px;
        line-height: 2.0;
        letter-spacing: 2px;
        font-weight: 200;
    }
}

@media (max-width: 1440px) {
    .tech-winter-container {
        padding: 0 150px;
    }
    
    .tech-winter-content {
        height: 500px;
    }
    
    .tech-winter-image {
        max-width: 50%;
        max-height: 50%;
        margin-top: 300px;
    }
    
    .tech-winter-right {
        margin-top: 80px;
    }
    
    .tech-winter-logo {
        max-width: 25%;
        margin-top: 0;
    }
    
    .tech-winter-title {
        font-size: 35px;
    }
    
    .tech-winter-description {
        font-size: 16px;
        width: 450px;
        line-height: 1.8;
        letter-spacing: 2px;
    }
    
    .tech-winter-gallery-container {
        margin-top: -42px;
    }
    
    .tech-winter-gallery {
        align-items: center;
        padding-right: 50px;
    }
    
    .gallery-item {
        width: 120px;
        height: 120px;
    }
    
    .gallery-item:nth-child(6),
    .gallery-item:nth-child(12) {
        height: 120px;
        max-width: 150px;
    }
    
    .third-section-text {
        margin-top: 100px;
    }
    
    .third-section-content {
        right: 100px;
    }
    
    .accordion-container {
        height: 550px;
        margin: 390px auto 0;
        max-width: 1200px;
    }
    
    .accordion-item {
        flex: 0 0 110px;
    }
    
    .accordion-item.active {
        flex: 0 0 900px;
    }
    
    .third-section-description {
        width: 600px;
        margin-right: 200px;
    }
    
    .fourth-section-title {
        font-size: 55px;
        line-height: 1.1;
        letter-spacing: 8px;
    }
    
    .fullscreen-video-section {
        margin-top: 50px;
    }
    
    .fourth-section-text {
        margin-left: 20px;
        width: 100%;
    }
    
    .fourth-section {
        background-size: 100% 100%;
    }
    
    .tech-winter-section {
        background-size: 100% 100%;
    }
}

@media (max-width: 1024px) {
    .tech-winter-container {
        padding: 0 100px;
    }
    
    .tech-winter-content {
        flex-direction: column;
        height: auto;
        align-items: center;
    }
    
    .tech-winter-image {
        max-width: 30%;
        max-height: 30%;
        margin-top: 180px;
    }
    
    .tech-winter-right {
        padding-left: 0;
        text-align: center;
        margin-top: 80px;
    }
    
    .tech-winter-logo {
        max-width: 14%;
        margin-top: 0;
    }
    
    .tech-winter-title {
        font-size: 30px;
    }
    
    .tech-winter-description {
        font-size: 14px;
        width: 100%;
        line-height: 1.8;
        letter-spacing: 2px;
    }
    
    .tech-winter-gallery {
        justify-content: center;
        padding-right: 0;
    }
}

@media (max-width: 768px) {
    .tech-winter-container {
        padding: 0 50px;
    }
    
    .tech-winter-image {
        max-width: 25%;
        max-height: 25%;
        margin-top: 150px;
    }
    
    .tech-winter-right {
        margin-top: 60px;
    }
    
    .tech-winter-logo {
        max-width: 10%;
    }
    
    .tech-winter-title {
        font-size: 25px;
    }
    
    .tech-winter-description {
        font-size: 12px;
        line-height: 1.8;
        letter-spacing: 2px;
    }
    
    .gallery-item {
        width: 100px;
        height: 100px;
    }
}

/* 图片放大效果 */
.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    overflow: auto;
    background-color: rgba(0,0,0,0.9);
}

.modal-content {
    display: block;
    margin: 10% auto;
    max-width: 80%;
    max-height: 80%;
}

.close {
    position: absolute;
    top: 20px;
    right: 30px;
    color: #f1f1f1;
    font-size: 40px;
    font-weight: bold;
    cursor: pointer;
}

.close:hover,
.close:focus {
    color: #bbb;
    text-decoration: none;
    cursor: pointer;
}