:root {
  --section-gap: 48px;
  --frame-border: #e0e0e0;
  --primary-color: #1a1a1a;
  --secondary-color: #555;
  --accent-color: #5b9bd5;
}

body {
  background: #ffffff;
  color: var(--primary-color);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  font-size: 18px;
  line-height: 1.8;
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

#main {
  margin-top: 60px;
  margin-bottom: 80px;
  max-width: 1400px;
  margin-left: auto;
  margin-right: auto;
  padding-left: 40px;
  padding-right: 40px;
}

/* ==================== 标题样式 ==================== */

h2 {
  margin-top: 0;
  margin-bottom: 24px;
  line-height: 1.25;
  font-size: 48px;
  font-weight: 700;
  letter-spacing: -0.02em;
}

h2 small {
  display: block;
  margin-top: 12px;
  font-size: 20px;
  font-weight: 400;
  color: var(--secondary-color);
}

h3 {
  margin-top: 0;
  margin-bottom: 24px;
  font-size: 32px;
  font-weight: 600;
  text-align: center;
  letter-spacing: -0.01em;
}

.section-title {
  margin-bottom: 20px;
}

/* ==================== 区块样式 ==================== */

.section {
  margin-top: var(--section-gap);
  padding-top: var(--section-gap);
  border-top: 1px solid var(--frame-border);
}

.section:first-of-type {
  border-top: none;
  padding-top: 0;
}

.section.section-tight {
  margin-top: 32px;
  padding-top: 32px;
}

/* ==================== 作者信息 ==================== */

.authors {
  margin-bottom: 8px;
}

.authors li {
  margin: 0 8px;
}

.authors a {
  font-size: 20px;
  font-weight: 500;
  color: var(--primary-color);
  text-decoration: none;
  transition: color 0.2s ease;
}

.authors a:hover {
  color: var(--accent-color);
}

.authors sup,
.affiliations sup {
  margin-right: 2px;
  color: var(--accent-color);
}

.affiliations-wrap {
  margin-top: 12px;
}

.affiliations {
  margin-bottom: 0;
}

.affiliations li {
  margin: 0 12px;
  font-size: 16px;
  color: var(--secondary-color);
}

/* ==================== CTA 按钮 ==================== */

.nav-pills > li > a {
  padding-top: 6px;
  padding-bottom: 10px;
}

.nav-pills > li > a h4 {
  margin-top: 8px;
  margin-bottom: 0;
}

.cta-nav {
  margin-top: 24px;
}

.cta-nav > li {
  padding-left: 8px;
  padding-right: 8px;
}

.cta-link {
  display: block;
  border: 2px solid var(--frame-border);
  border-radius: 16px;
  background: #ffffff;
  padding: 20px 16px;
  transition: all 0.2s ease;
}

.cta-link:hover,
.cta-link:focus {
  border-color: var(--primary-color);
  background: #fafafa;
  text-decoration: none;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
  transform: translateY(-2px);
}

.cta-primary {
  border-color: var(--primary-color);
}

.cta-link img {
  display: block;
  margin-left: auto;
  margin-right: auto;
}

.cta-link h4 {
  font-size: 18px;
  font-weight: 600;
}

.cta-subtitle {
  display: block;
  margin-top: 4px;
  font-size: 13px;
  line-height: 1.25;
  font-weight: 400;
  color: var(--secondary-color);
}

.cta-subtitle-hidden {
  visibility: hidden;
}

a.disabled-link {
  pointer-events: none;
  opacity: 0.4;
}

/* ==================== 图片样式 ==================== */

img {
  max-width: 100%;
}

.figure-frame {
  border: 1px solid var(--frame-border);
  border-radius: 12px;
  background: #fafafa;
  padding: 12px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.04);
}

.figure-cols {
  margin-left: -12px;
  margin-right: -12px;
}

.figure-cols > [class*="col-"] {
  padding-left: 12px;
  padding-right: 12px;
}

.figure-item {
  margin: 0;
}

.figure-caption {
  margin-top: 12px;
  margin-bottom: 0;
  font-size: 16px;
  line-height: 1.6;
  font-weight: 400;
  color: var(--secondary-color);
  text-align: center;
}

/* ==================== 正文内容 ==================== */

.lead {
  font-size: 20px;
  line-height: 1.9;
  font-weight: 400;
  color: var(--primary-color);
  text-align: justify;
}

.abstract-block {
  max-width: 1100px;
  margin-left: auto;
  margin-right: auto;
  padding: 0;
}

/* ==================== 引用区块 ==================== */

.citation-block {
  margin-top: 16px;
}

#copy-bibtex {
  margin-top: 8px;
  border-radius: 8px;
  font-weight: 500;
  transition: all 0.2s ease;
}

#copy-bibtex:hover {
  background: var(--primary-color);
  color: #fff;
  border-color: var(--primary-color);
}

#bibtex {
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
  font-size: 14px;
  line-height: 1.6;
  border-radius: 8px;
  background: #f8f9fa;
  border-color: var(--frame-border);
}

/* ==================== 内容居中容器 ==================== */

.content-wrapper {
  max-width: 960px;
  margin-left: auto;
  margin-right: auto;
}

/* ==================== 响应式 ==================== */

@media (max-width: 992px) {
  :root {
    --section-gap: 36px;
  }

  #main {
    margin-top: 40px;
    margin-bottom: 60px;
  }

  h2 {
    font-size: 36px;
  }

  h3 {
    font-size: 26px;
  }

  .authors a {
    font-size: 18px;
  }

  .affiliations li {
    font-size: 14px;
  }
}

@media (max-width: 768px) {
  :root {
    --section-gap: 28px;
  }

  #main {
    margin-top: 24px;
    padding-left: 16px;
    padding-right: 16px;
  }

  h2 {
    font-size: 28px;
  }

  h2 small {
    font-size: 16px;
  }

  h3 {
    font-size: 22px;
    margin-bottom: 16px;
  }

  .lead {
    font-size: 17px;
    line-height: 1.8;
  }

  .figure-frame {
    padding: 8px;
    border-radius: 8px;
  }

  .authors li {
    margin: 4px 6px;
  }

  .affiliations li {
    display: block;
    margin: 4px 0;
  }
}

@media (min-width: 1200px) {
  .affiliations {
    white-space: nowrap;
  }
}