.gallery {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); /* 自适应列数 */
  gap: 12px;             /* 照片间距 */
}
.gallery img {
  width: 100%;
  height: 100%;
  aspect-ratio: 4 / 3;   /* 固定比例，可改为 1/1 等 */
  object-fit: cover;     /* 居中裁剪，保持整齐 */
  border-radius: 10px;
  display: block;
}



.four-photos {
  display: flex;
  gap: 12px;        /* 照片之间的间距 */
  max-width: 900px;
  margin: 0 auto;
}
.four-photos img {
  flex: 1;          /* 平均分三份 */
  height: 150px;
  object-fit: cover;
  border-radius: 8px;
}

figcaption {
  text-align: center;
}


.container {
  max-width: 950px;   /* 和正文一样的宽度 */
  margin: 0 auto;     /* 居中 */
  padding: 0 20px;    /* 内边距，避免文字贴边 */
}


.content {
  max-width: 950px;   /* 最大宽度，比如 800px */
  margin: 0 auto;     /* 左右自动居中 */
  padding: 20px;      /* 内边距，避免文字贴边 */
  line-height: 1.6;   /* 行间距，更好阅读 */
}

html {
  scroll-behavior: smooth;  /* 点击锚点平滑滚动 */
  font-family: Helvetica Neue, sans-serif;
}

/* 导航栏容器 */
.navbar {
  position: fixed;   /* 固定在顶部 */
  top: 0;
  left: 0;
  width: 100%;
  background-color: #fff;
  border-bottom: 2px solid #eee;
  overflow: hidden;
  padding: 10px 0;
  z-index: 1000;     /* 确保在最上层 */
}

.navbar .container {
  padding: 0; 
  display: flex;      /* 横向排布 */
  justify-content: flex-end; /* 让链接平均分布 */
  gap: 20px;
}


/* 按钮风格导航 */
.nav-btn {
  padding: 8px 8px;
  border-radius: 8px;
  text-decoration: none;
  font-weight: 500;
  color: #777777;
  background: #fff;
  transition: all 0.2s ease;
}

/* 悬停效果 */
.nav-btn:hover {
  background: #fff; /* 主色 */
  color: #333;
  text-decoration: underline;
}

/* 当前选中（高亮） */
.nav-btn.active {
  background: #2b6aff;
  color: white;
}


/* .navbar a {
  color: #f2f2f2;
  text-decoration: none;
  padding: 14px 20px;
}

.navbar a:hover {
  background-color: #ddd;
  color: black;
} */

/* 给正文留出顶部空间，避免被导航栏挡住 */
section {
  padding: 20px 0;
  margin-top: 20px;     
  scroll-margin-top: 60px;
}


a {
  /* color: #196CD1; */
  color: #2470ce;
  text-decoration: none;
}

a:focus,
a:hover,
author:focus,
author:hover {
  /* color: #B908C5; */
  text-decoration: underline;
  }

body,
td,
th,
li,
tr{
  font-family: "Helvetica Neue", sans-serif;
  font-size: 16px;
  color: #404040;
  line-height: 1.4;
}

p{
  font-family: "Helvetica Neue", sans-serif;
  font-size: 16px;
  color: #404040;
  margin:0;
  line-height: 1.4;
}

papertext,
author{
  font-family: "Helvetica Neue", sans-serif;
  font-size: 16px;
  color: #777777;
  line-height: 1.4;
}

a{
  font-family: "Helvetica Neue", sans-serif;
  font-size: 16px;
}

strong {
  font-family: "Helvetica Neue", sans-serif;
  font-size: 16px;
  color: #333333;
}

heading{
  font-family: "Helvetica Neue", sans-serif;
  font-size: 22px;
  color: #333333;
}

talktitle,
papertitle {
  font-family: "Helvetica Neue", sans-serif;
  font-size: 16px;
  font-weight: 700;
  color: #333333;
  line-height: 1.4;
}

name {
  font-family: "Helvetica Neue", sans-serif;
  font-size: 36px;
  color: #333333;
  line-height: 1.8;
}

.one {
  width: 160px;
  height: 160px;
  position: relative;
}

.two {
  width: 160px;
  height: 160px;
  position: absolute;
  transition: opacity .2s ease-in-out;
  -moz-transition: opacity .2s ease-in-out;
  -webkit-transition: opacity .2s ease-in-out;
}

.fade {
  transition: opacity .2s ease-in-out;
  -moz-transition: opacity .2s ease-in-out;
  -webkit-transition: opacity .2s ease-in-out;
}

span.highlight {
  background-color: #ffffd0;
}

h2{
  font-family: "Helvetica Neue", sans-serif;
  font-size: 20px;
  margin:0;
  line-height: 3;
  color: #333333;
}


h3{
  font-family: "Helvetica Neue", sans-serif;
  font-size: 18px;
  color: #333333;
}

h4{
  font-family: "Helvetica Neue", sans-serif;
  font-size: 16px;
  margin:0;
  color: #333333;
}

ul {
  margin: 0;
}