body {
    padding-top: 0 ;
}

.navbar {
    background-color: rgba(117, 125, 33, 0.6);
    z-index: 10;
} 


.banner {
    display: flex;
    align-items: flex-start;
    justify-content: center;
    position: relative;
    height: 100vh;
    text-align: center;
    color: #fff;
    /* 先显示纯色背景，避免白屏 */
    background-color: #2c3e50;
    /* 保留原背景图片设置，方便切换 */
    background-image: linear-gradient(rgba(0, 0, 0, 0.5), rgba(0, 0, 0, 0.5)), url('../images/unnamed.jpg');
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    background-attachment: fixed;
    overflow: hidden;
    /* 添加过渡效果，使背景图片加载更平滑 */
    transition: background-image 0.3s ease-in-out;
}

/* 视频背景样式 */
.banner-video {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    z-index: 1;
    opacity: 1;
}

/* 保持半透明遮罩效果 */
.banner::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    z-index: -1;
}

.banner .content {
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    max-width: 1200px;
    height: 60vh;
    margin: 25vh auto 0;
    padding: 0 1rem;
    position: relative;
    z-index: 10;
}

.banner .title {
    margin-bottom: auto;
}

.banner h2 {
    margin-bottom: 1rem;
    font-size: 3.75rem;
    font-weight: 600;
}

.banner h1 {
    margin-bottom: 1rem;
    font-size: 4.5rem;
    line-height: 1.2;
    font-weight: 700;
}

.banner h3 {
    margin-bottom: 3rem;
    font-size: 1.5rem;
    font-weight: 600;
}

.banner .btn {
    display: inline-flex;
    flex-direction: column;
    align-items: center;
    margin-bottom: 2rem;
    font-size: 2rem;
    color: #fff;
    transition: all 0.3s ease;
    animation: floating 2s ease-in-out infinite;
}

.banner .btn span {
    margin-bottom: 1rem;
    font-weight: 300;
}

.banner .btn .icon {
    width: 48px;
    height: 48px;
    padding: 8px;
    fill: currentColor;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    transition: all 0.3s ease;
}

.banner .btn:hover {
    color: #69c0ff;
}

.banner .btn:hover .icon {
    border-color: #69c0ff;
}

@media (max-width: 768px) {
    .banner h1 {
        font-size: 3.75rem;
    }

    .banner h2 {
        font-size: 1.5rem;
    }

    .banner h3 {
        font-size: 1.25rem;
    }

    .banner .btn {
        font-size: 1.5rem;
    }

    .banner .btn .icon {
        width: 40px;
        height: 40px;
        padding: 6px;
    }
}

@media (max-width: 480px) {
    .banner h1 {
        font-size: 3rem;
    }

    .banner h2 {
        font-size: 1.25rem;
    }

    .banner h3 {
        font-size: 1rem;
    }
}

@keyframes floating {
    0% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(15px);
    }
    100% {
        transform: translateY(0);
    }
}

.about {
    padding: 6rem 0;
}

.about .intro {
    margin: 0 auto 6rem;
}

.about .intro h2 {
    margin-bottom: 2rem;
    font-size: 3.75rem;
    line-height: 1;
    color: rgba(117, 125, 33, 0.8);
    color: inherit;
}

.about .intro p {
    font-size: 1.5rem;
    line-height: 2rem;
    text-align: justify;
    color: rgba(117, 125, 33, 0.8);
    color: inherit;
}

.about .intro .link {
    color: rgba(117, 125, 33, 0.6);
}

.about .grid {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    margin: -2rem -1.25rem;
}

.about .grid .item {
    display: contents;
}

.about .grid .image {
    grid-column: span 1;
    justify-self: end;
    width: 200px;
    height: 200px;
    border-radius: 50%;
    overflow: hidden;
    margin: 2rem 1.25rem;
}

.about .grid .content {
    grid-column: span 2;
    align-self: center;
    margin: 2rem 1.25rem;
}

.about .grid .item.reverse .image {
    grid-column: 5/6;
}

.about .grid .item.reverse .content {
    grid-column: 3/5;
    text-align: right;
}

.about .grid .image img {
    width: 100%;
    height: 100%;
    object-fit: fill;
}

.about .grid h3 {
    margin-bottom: 1rem;
    font-size: 1.5rem;
    line-height: 2rem;
    font-weight: 700;
    text-align: left;
    color: rgba(117, 125, 33, 0.8);
    color: inherit;
}

.about .grid p {
    font-size: 1.125rem;
    font-weight: 400;
    line-height: 1.75rem;
    color: #000;
    text-align: justify;
}

@media (max-width: 1024px) {
    .about .grid .image {
        width: 160px;
        height: 160px;
    }

    .about .grid h3 {
        font-size: 1.25rem;
        line-height: 1.75rem;
    }

    .about .grid p {
        font-size: 1rem;
        line-height: 1.5rem;
    }
}

@media (max-width: 768px) {
    .banner h1 {
        font-size: 3rem;
    }

    .banner h2 {
        font-size: 1.5rem;
    }

    .banner h3 {
        font-size: 1.25rem;
    }

    .banner .btn {
        font-size: 1.5rem;
    }

    .banner .btn .icon {
        width: 40px;
        height: 40px;
        padding: 6px;
    }

    .about {
        padding: 4rem 0;
    }

    .about .intro {
        margin-bottom: 4rem;
        padding: 0 1rem;
    }

    .about .grid {
        display: grid;
        grid-template-columns: repeat(3, 1fr);
        margin: -1.25rem;
        padding: 0 1rem;
    }

    .about .grid .image {
        width: 90px;
        height: 90px;
        grid-column: span 1;
        margin: 1.25rem;
    }

    .about .grid .content {
        grid-column: span 2;
        margin: 1.25rem;
    }

    .about .grid .item.reverse .image {
        grid-column: 3/4;
    }

    .about .grid .item.reverse .content {
        grid-column: 1/3;
        text-align: right;
    }

    .about .grid h3 {
        margin-bottom: 0.5rem;
        font-size: 0.75rem;
        line-height: 1rem;
    }

    .about .grid p {
        font-size: 0.75rem;
        line-height: 1rem;
    }
}

@media (max-width: 640px) {
    .about .intro h2 {
        font-size: 1.25rem;
        line-height: 1.75rem;
    }

    .about .intro p {
        font-size: 1.25rem;
        line-height: 1.75rem;
    }
}

@media (max-width: 480px) {
    .banner h1 {
        font-size: 2.5rem;
    }

    .banner h2 {
        font-size: 1.25rem;
    }

    .banner h3 {
        font-size: 1rem;
    }

    .about .intro h2 {
        font-size: 2rem;
    }

    .about .intro p {
        font-size: 1rem;
    }

    .about .grid .image {
        width: 90px;
        height: 90px;
    }
}

/* Quote section styles */
.quote {
    padding: 4rem 0;  /* 上下间距 */
    background-color: #f8f9fa;  /* 可选：浅色背景 */
}

.quote .wrapper {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

.quote-text {
    font-size: 1.25rem;  /* 字体大小，可调整 */
    line-height: 2;  /* 行高 */
    text-align: center;  /* 居中对齐 */
    color: #555;  /* 文字颜色 */
    font-style: italic;  /* 斜体 */
    margin: 0;
}

/* 摘要展开/收起动画效果 */
.abstract-content {
    overflow: hidden;
    transition: all 0.3s ease-in-out;
    max-height: 1000px;
    opacity: 1;
    padding-top: 0.5rem;
}

.abstract-content.hide {
    max-height: 0;
    opacity: 0;
    padding-top: 0;
}

.toggle-icon {
    margin-left: 0.5rem;
    transition: transform 0.3s ease-in-out;
    display: inline-block;
}

.toggle-icon.rotated {
    transform: rotate(180deg);
}

/* 研究项目滑入动画 */
.research-item {
    opacity: 0;
    transform: translateY(50px);
    transition: all 0.6s ease-out;
}

.research-item.slide-in {
    opacity: 1;
    transform: translateY(0);
}

/* 研究项目标题悬停效果 */
.research-item h2:hover {
    color: #555 !important;
}

@media (max-width: 768px) {
    .quote {
        padding: 3rem 0;  /* 移动端减小间距 */
    }

    .quote-text {
        font-size: 1rem;  /* 移动端字体缩小 */
    }
}