/* 全局样式 */
body {
    display: flex;
    justify-content: center;
    align-items: center;
    flex-direction: column;
    font - family: Arial, sans - serif;
    /* font-family:"Palatino Linotype", "Book Antiqua", Palatino, serif; */
    margin: 0;
    padding: 0;
    line - height: 1.6;
    min-height: 100vh;
    background-image:url("image/bg2.jpg");
    
    background-repeat: no-repeat;
    
    background-size: 100% 5.5%;
  }
  
header {
    text - align: center;
    padding: 20px;
    background - color: #f4f4f4;
  }
  
header h1 {
    margin - bottom: 20px;
    /* font-size:42px; */
  }
  
.author{
  text - align: center; 
  font-size: 20px;
}

  .button - group {
    text - align: center; 
    
  }
  
  .button-group a {
    display: inline-block; 
    padding: 12px 24px;
    margin: 8px; 
    background-color: white; 
    color: black; 
    text-decoration: underline; 
    font-size: 16px;
    font-weight: bold;
    border-radius: 10px; 
    border: 2px solid white; 
    transition: all 0.3s ease; 
}
.button-group a:hover {
  background-color: #f0f0f0; 
}
  

  .abs{
    margin-top: 40px; 
    padding: 40px;
    width:70%;
    font-size:18px;
    line-height: 1.5; 
    letter-spacing: 0.6px;
    /* font-family:"Palatino Linotype", "Book Antiqua", Palatino, serif; */
  }

  

.modelstructure {
    
  padding: 20px;
  width:70%;
}
.image-container {
  text-align: center;
}
img {
  max-width: 85%;
  max-height: 100%;
  display: block;
  margin: 0 auto;
}

.contribution {
    
  padding: 20px;
  width:70%;
  font-size:18px;
    line-height: 1.5; 
    letter-spacing: 0.6px;
}
.comparison {
    
  padding: 20px;
  width:100%;
  font-size:18px;
  line-height: 1.5; 
  letter-spacing: 0.6px;
}

  .demos {
    
    padding: 20px;
    width:70%;
  }
  .big-demo{
    text-align: center;
  }
  .big-demo video{
    
    max-width: 80%;
  max-height: 100%;
  }

  .littledemo-row {
    text-align: center;
    margin-left: 100px;
    margin-right: 100px;
    max-width: 100%;

    display: flex;  
    justify-content: space-between;  
    flex-wrap: wrap;  
  }
  
  .littledemo-item {
    padding:0px;
    width: 47%;  
    margin: 10px 0;  
    text-align: center; 
  }
  
  .demo-row {
    /* margin-bottom: 180px; */
    display: flex;  
    justify-content: space-between;  
    flex-wrap: wrap;  
  }
  
  .demo-item {
    padding:0px;
    width: 22%;  
    margin: 10px 0;  
    text-align: center;  
  }
  
  video {
    width: 100%;  
    height: auto;  
  }

  
  .audio-container {
    display: flex;
   
    gap: 10px; 
}

.vggsoundplus{
  padding: 20px;
    width:70%;
    margin-bottom: 180px;
}

.centered-link {
  text-align: center;
}
.download-link {
  
  font-size: 18px;
  font-weight: bold;
  text-decoration: none;
  color: #54a8dd; 
  transition: color 0.3s ease-in-out;
}

.download-link:hover {
  color: #0056b3; 
}


#video-selector {
    width: 100%;
    max-width: 1400px;
    margin: 20px auto;
    display: flex;
    flex-direction: column; /* Stack the rows vertically */
    gap: 80px; /* Increase space between video rows */
}
.chapter-title {
    /* font-family: 'Quicksand', sans-serif;  */
    font-size: 26px;
    text-align: center;
    margin-bottom: 5px;
    line-height:1.5;
    letter-spacing: 0.6px;
}

.chapter-line {
    border: none;
    border-top: 2px solid #d0d0d0; 
    margin-top: 5px;
    margin-bottom: 5px;
    text-align: left;
}
.section {
    background-color: #ffffff; /* White background for section */
    padding: 20px;
    border-radius: 10px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1); /* Light shadow for separation */
    margin-bottom: 40px; /* Add space below each section */
}
.section-title {
    font-size: 24px;
    color: #333;
    margin-bottom: 20px;
}
/* .video-row {
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 5px; */

.video-row {
    display: grid;
    grid-template-columns: repeat(5, minmax(220px, 1fr));
    gap: 12px;
    margin-bottom: 16px;
}
/* Each video column size, reducing the width to fit 4 per row */
.video-column {
    /* width: 10%; /* Make the videos smaller to fit 4 per row 
    margin-bottom: 20px; */
    display: flex;
    flex-direction: column;
    align-items: center;
}

.video-player-container {
    width: 100%;
    aspect-ratio: 16 / 9;
    position: relative;
}
.video-player-container iframe {
    width: 100%;
    height: 100%;
    border-radius: 6px;
    border: none;
}

.YT-AMBISEM{
  padding: 20px;
    width:70%;
    margin-bottom: 180px;
}

.centered-link {
  text-align: center;
}
.download-link {
  
  font-size: 18px;
  font-weight: bold;
  text-decoration: none;
  color: #54a8dd; 
  transition: color 0.3s ease-in-out;
}

.download-link:hover {
  color: #0056b3; 
}