.bib-btn {
  background: none;
  border: none;
  color: #0097e6;     /* 蓝色主题 */
  padding: 0;
  cursor: pointer;
  font: inherit;
  font-size: 1.1em;
}

.bib-btn:hover {
  text-decoration: underline;
}

/* 弹层整体 */
#bib-popover {
  position: absolute;
  z-index: 9999;
  max-width: 720px;
  min-width: 360px;
  background: #f4faff; /* 浅蓝背景 */
  border: 1px solid #cce4f6;
  border-radius: 12px;
  box-shadow: 0 8px 28px rgba(0,0,0,.12);
  overflow: hidden;
  transition: all 0.2s ease;
}

/* 顶部工具栏 */
#bib-popover .bib-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 12px;
  font-weight: 600;
  background: #e6f3fc;  /* 工具栏背景更深一点的浅蓝 */
  border-bottom: 1px solid #cce4f6;
  color: #0366d6;
}

/* Copy 按钮 */
#bib-copy-btn {
  background: #0097e6;
  color: #fff;
  border: none;
  border-radius: 6px;
  padding: 6px 14px;
  cursor: pointer;
  font-size: 0.9rem;
  font-weight: 500;
  transition: background 0.2s ease, transform 0.15s ease;
}

#bib-copy-btn:hover {
  background: #007bbf;  /* 悬停时更深蓝 */
  transform: translateY(-1px);
  box-shadow: 0 2px 6px rgba(0,151,230,0.3);
}

#bib-copy-btn:active {
  transform: translateY(0); /* 点击时回落 */
  box-shadow: none;
}

/* Bibtex 内容块 */
#bib-popover pre {
  margin: 0;
  padding: 12px 14px;
  max-height: 50vh;
  overflow: auto;
  background: #ffffff; /* 白底 */
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", monospace;
  font-size: 13px;
  line-height: 1.5;
  color: #2d3436;
  border-top: 1px solid #e3edf7;
}

/* 小箭头 */
#bib-popover::after {
  content: "";
  position: absolute;
  top: -8px;
  left: 24px;
  border-width: 8px;
  border-style: solid;
  border-color: transparent transparent #f4faff transparent;
  filter: drop-shadow(0 -1px 0 #cce4f6);
}