/* ReadingBook 聊天挂件 —— 学术典雅配色，与站点设计系统一致 */
#bc-fab {
  position: fixed; right: 22px; bottom: 22px; z-index: 9000;
  display: inline-flex; align-items: center; gap: 8px;
  padding: 11px 17px; border: none; border-radius: 999px; cursor: pointer;
  font-family: var(--sans); font-size: 15px; font-weight: 600; color: #fff;
  background: var(--primary, #2d4a6b);
  box-shadow: 0 6px 20px rgba(45,74,107,.32);
  transition: transform .15s ease, box-shadow .15s ease, background .15s;
}
#bc-fab:hover { transform: translateY(-2px); box-shadow: 0 10px 28px rgba(45,74,107,.4); background: var(--primary-deep, #1f3349); }
#bc-fab .bc-fab-ic { font-size: 18px; }

#bc-panel {
  position: fixed; right: 0; top: 0; z-index: 9001;
  width: min(440px, 100vw); height: 100vh;
  display: flex; flex-direction: column;
  background: var(--paper, #f6f1e7);
  border-left: 1px solid var(--line, #e6dcc8);
  box-shadow: -12px 0 40px rgba(60,40,10,.16);
  transform: translateX(100%); transition: transform .26s cubic-bezier(.4,0,.2,1);
  font-family: var(--sans);
}
#bc-panel.open { transform: translateX(0); }

.bc-head {
  display: flex; align-items: center; gap: 10px;
  padding: 14px 16px; border-bottom: 1px solid var(--line, #e6dcc8);
  background: var(--surface, #fffdf8);
}
.bc-head .bc-title { font-weight: 700; color: var(--ink, #2b2724); font-size: 15px; flex: 1; line-height: 1.3; }
.bc-head .bc-title small { display:block; font-weight: 500; color: var(--ink-soft, #6b6155); font-size: 12px; margin-top: 2px; }
.bc-head .bc-head-btns { display: flex; align-items: center; gap: 4px; }
.bc-head .bc-clear { border: 1px solid var(--line, #e6dcc8); background: none; cursor: pointer; font-size: 12px; color: var(--ink-soft, #6b6155); line-height: 1; padding: 5px 9px; border-radius: 8px; }
.bc-head .bc-clear:hover { background: var(--surface-2, #fbf6ec); color: var(--accent, #a8500f); border-color: var(--accent, #a8500f); }
.bc-head .bc-x { border: none; background: none; cursor: pointer; font-size: 22px; color: var(--ink-faint, #938873); line-height: 1; padding: 2px 6px; border-radius: 8px; }
.bc-head .bc-x:hover { background: var(--surface-2, #fbf6ec); color: var(--ink, #2b2724); }

.bc-scope {
  display: flex; align-items: center; gap: 8px; flex-wrap: wrap;
  padding: 9px 16px; border-bottom: 1px solid var(--line-soft, #efe7d6);
  background: var(--surface, #fffdf8); font-size: 12.5px; color: var(--ink-soft, #6b6155);
}
.bc-scope select {
  font-family: var(--sans); font-size: 12.5px; color: var(--ink, #2b2724);
  background: var(--paper, #f6f1e7); border: 1px solid var(--line, #e6dcc8);
  border-radius: 7px; padding: 3px 6px; max-width: 200px;
}
.bc-modes { margin-left: auto; display: inline-flex; border: 1px solid var(--line, #e6dcc8); border-radius: 7px; overflow: hidden; }
.bc-modes button { border: none; background: var(--paper, #f6f1e7); cursor: pointer; font-size: 12px; padding: 3px 9px; color: var(--ink-soft, #6b6155); }
.bc-modes button.on { background: var(--primary, #2d4a6b); color: #fff; }

.bc-body { flex: 1; overflow-y: auto; padding: 14px 16px; display: flex; flex-direction: column; gap: 12px; }

.bc-msg { display: flex; flex-direction: column; gap: 4px; }
.bc-msg .bc-role { font-size: 11px; color: var(--ink-faint, #938873); font-weight: 600; }
.bc-bubble {
  padding: 10px 13px; border-radius: 12px; font-size: 14.5px; line-height: 1.68;
  color: var(--ink, #2b2724); word-wrap: break-word;
}
.bc-msg.user { align-items: flex-end; }
.bc-msg.user .bc-bubble { background: var(--primary-tint, #eaf0f6); border: 1px solid #d6e0ec; max-width: 88%; }
.bc-msg.ai .bc-bubble { background: var(--surface, #fffdf8); border: 1px solid var(--line, #e6dcc8); box-shadow: var(--shadow-card); }
.bc-bubble p { margin: 0 0 8px; } .bc-bubble p:last-child { margin-bottom: 0; }
.bc-bubble h2,.bc-bubble h3 { font-size: 15px; margin: 10px 0 6px; color: var(--primary-deep, #1f3349); }
.bc-bubble ul,.bc-bubble ol { margin: 4px 0 8px; padding-left: 20px; }
.bc-bubble li { margin: 3px 0; }
.bc-bubble blockquote { margin: 6px 0; padding: 6px 12px; border-left: 3px solid var(--accent, #a8500f); background: var(--accent-tint, #f7ece0); border-radius: 0 8px 8px 0; font-size: 13.5px; }
.bc-bubble code { background: var(--surface-2, #fbf6ec); padding: 1px 5px; border-radius: 5px; font-size: 13px; }
.bc-bubble a { color: var(--primary, #2d4a6b); text-decoration: underline; text-underline-offset: 2px; }

.bc-status { font-size: 12.5px; color: var(--ink-soft, #6b6155); font-style: italic; display: flex; align-items: center; gap: 6px; }
.bc-status .bc-dot { width: 7px; height: 7px; border-radius: 50%; background: var(--accent, #a8500f); animation: bc-pulse 1s infinite; }
@keyframes bc-pulse { 0%,100%{opacity:.3} 50%{opacity:1} }

.bc-suggest { display: flex; flex-direction: column; gap: 7px; }
.bc-suggest .bc-sg-title { font-size: 12px; color: var(--ink-faint, #938873); }
.bc-chip {
  text-align: left; border: 1px solid var(--line, #e6dcc8); background: var(--surface, #fffdf8);
  border-radius: 10px; padding: 8px 11px; font-size: 13.5px; color: var(--ink, #2b2724);
  cursor: pointer; font-family: var(--sans); line-height: 1.4; transition: border-color .15s, background .15s;
}
.bc-chip:hover { border-color: var(--primary, #2d4a6b); background: var(--primary-tint, #eaf0f6); }

.bc-foot { padding: 12px 16px; border-top: 1px solid var(--line, #e6dcc8); background: var(--surface, #fffdf8); }
.bc-inwrap { display: flex; gap: 8px; align-items: flex-end; }
.bc-foot textarea {
  flex: 1; resize: none; max-height: 120px; min-height: 40px;
  border: 1px solid var(--line, #e6dcc8); border-radius: 10px; padding: 9px 11px;
  font-family: var(--sans); font-size: 14px; color: var(--ink, #2b2724); background: var(--paper, #f6f1e7);
  line-height: 1.5;
}
.bc-foot textarea:focus { outline: none; border-color: var(--primary, #2d4a6b); }
.bc-send { border: none; border-radius: 10px; background: var(--primary, #2d4a6b); color: #fff; cursor: pointer; padding: 0 16px; height: 40px; font-size: 14px; font-weight: 600; }
.bc-send:disabled { opacity: .5; cursor: default; }
.bc-hint { font-size: 11px; color: var(--ink-faint, #938873); margin-top: 6px; text-align: center; }

@media (max-width: 600px) { #bc-panel { width: 100vw; } #bc-fab span.bc-fab-tx { display: none; } }