body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    line-height: 1.6;
    background-color: #fafafa;
    color: #333;
}

header {
    text-align: center;
    padding: 30px;
    background: #f0f0f0;
}

header h1 {
    margin: 0;
}

header a {
    margin: 0 10px;
    text-decoration: none;
    color: #007acc;
}

.teaser img {
    display: block;
    margin: 20px auto;
    max-width: 90%;
}

section {
    max-width: 900px;
    margin: auto;
    padding: 20px;
}

pre {
    background: #eee;
    padding: 10px;
    overflow-x: auto;
}

body {
    font-family: 'Segoe UI', Tahoma, sans-serif;
    margin: 0;
    padding: 0;
    background-color: white;
    color: #333;
    line-height: 1.6;
}
nav {
    position: fixed;
    width: 100%;
    background: #ffffff19;
    backdrop-filter: blur(8px);
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    z-index: 100;
}
.nav-container {
    max-width: 1100px;
    margin: auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px 20px;
}
.logo {
    font-weight: bold;
    font-size: 20px;
    color: #ffffff;
    text-decoration: none;
}
.nav-links {
    list-style: none;
    display: flex;
    gap: 20px;
}
.nav-links a {
    text-decoration: none;
    color: #ffffff;
    transition: color 0.3s;
}
.nav-links a:hover {
    color: #007acc;
}
.menu-toggle {
    display: none;
    flex-direction: column;
    cursor: pointer;
    gap: 4px;
}
.menu-toggle span {
    width: 25px;
    height: 3px;
    background: #333;
    transition: all 0.3s;
}
.hero {
    background: linear-gradient(to right, #007acc, #00b4d8);
    color: white;
    padding: 100px 20px;
    text-align: center;
}
.hero h1 {
    margin: 0;
    font-size: 48px;
}
.subtitle {
    font-size: 20px;
    margin-top: 10px;
}
.authors {
    margin-top: 10px;
}

.links {
    width: 100%;
    display: flex;
    flex-direction: row;
    align-items: center;
    justify-content: center;
}

.links .btn {
    margin: 10px;
    background: rgba(255, 255, 255, 0.433);
    color: #ffffff;
    text-decoration: none;
    border-radius: 5px;
    transition: background 0.3s;
}

.btn {
    width: 90px;
    height: 40px;
    display: flex;
    flex-direction: row;
    align-items: center;
    justify-content: center;
}

.links .btn:hover {
    background: #e8f2ff;
}
.teaser img {
    display: block;
    margin: 40px auto;
    max-width: 90%;
    border-radius: 8px;
    /* box-shadow: 0 4px 8px rgba(0,0,0,0.1); */
}
section {
    max-width: 900px;
    margin: auto;
    padding: 40px 20px;
}
h2 {
    border-bottom: 2px solid #007acc;
    padding-bottom: 5px;
    margin-bottom: 20px;
}
.video-container {
    position: relative;
    padding-bottom: 56.25%;
    height: 0;
}
.video-container iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}
pre {
    background: #eee;
    padding: 15px;
    border-radius: 5px;
    overflow-x: auto;
}
footer {
    text-align: center;
    padding: 20px;
    background: #f0f0f0;
    font-size: 14px;
}
@media (max-width: 768px) {
    .nav-links {
        position: absolute;
        top: 60px;
        right: 20px;
        background: white;
        flex-direction: column;
        gap: 10px;
        padding: 10px;
        display: none;
        box-shadow: 0 2px 8px rgba(0,0,0,0.15);
    }
    .nav-links.active {
        display: flex;
    }
    .menu-toggle {
        display: flex;
    }
}

.sec > img {
    margin: auto;
    display: block;
    max-width: 90%;
}

.sec > video {
    margin: auto;
    display: block;
    max-width: 90%;
}


/* ------------------------------ */
/*   Header background slideshow  */
/* ------------------------------ */

.hero {
    position: relative;
    height: 380px; /* 根据需要调节 */
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    animation: bgSlide 18s infinite;
}

/* 三张背景图轮换 */
@keyframes bgSlide {
    0%   { background-image: url("images/demo1.png"); }
    33%  { background-image: url("images/demo2.png"); }
    67%  { background-image: url("images/demo3.png"); }
    100% { background-image: url("images/demo1.png"); }
}

/* 给标题增加一点描边，防止背景过亮影响可读性 */
.hero h1,
.hero .subtitle,
.hero p {
    text-shadow: 0 0 8px rgba(0,0,0,0.55);
}


/* ------------------------- */
/* Nav style when scrolled   */
/* ------------------------- */
nav.scrolled {
    background: #ffffffee; /* 不透明白色 */
    backdrop-filter: blur(4px);
    box-shadow: 0 2px 6px rgba(0,0,0,0.12);
}

nav.scrolled .logo {
    color: #222;
}

nav.scrolled .nav-links a {
    color: #222;
}

nav.scrolled .nav-links a:hover {
    color: #007acc;
}

/* menu icon also change */
nav.scrolled .menu-toggle span {
    background: #222;
}