/* ============================================================
   FluidLab AI — AI辅导面板样式 (BEM命名, fl-前缀)
   深色主题: --primary: #00f2ff, --bg-deep: #08090d
   ============================================================ */

/* 面板容器 */
.fl-tutor-panel {
  position: fixed;
  top: 0;
  right: -420px;
  width: 400px;
  height: 100vh;
  background: rgba(10, 14, 22, 0.96);
  backdrop-filter: blur(20px);
  border-left: 1px solid rgba(0, 242, 255, 0.15);
  z-index: 9999;
  display: flex;
  flex-direction: column;
  transition: right 0.35s cubic-bezier(0.4, 0, 0.2, 1);
  box-shadow: -8px 0 32px rgba(0, 0, 0, 0.5);
}

.fl-tutor-panel--open {
  right: 0;
}

/* 面板头部 */
.fl-tutor-panel__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 18px;
  background: linear-gradient(135deg, rgba(0, 242, 255, 0.08), rgba(0, 242, 255, 0.02));
  border-bottom: 1px solid rgba(0, 242, 255, 0.1);
  flex-shrink: 0;
}

.fl-tutor-panel__title {
  font-size: 16px;
  font-weight: 600;
  color: #00f2ff;
  display: flex;
  align-items: center;
  gap: 8px;
}

.fl-tutor-panel__title-icon {
  font-size: 20px;
}

.fl-tutor-panel__close {
  width: 28px;
  height: 28px;
  border: none;
  background: rgba(255, 255, 255, 0.06);
  color: #94a3b8;
  border-radius: 6px;
  cursor: pointer;
  font-size: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.2s;
}

.fl-tutor-panel__close:hover {
  background: rgba(255, 77, 77, 0.2);
  color: #ff4d4d;
}

/* 额度提示栏 */
.fl-tutor-panel__quota {
  padding: 8px 18px;
  background: rgba(0, 242, 255, 0.04);
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
  font-size: 12px;
  color: #94a3b8;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-shrink: 0;
}

.fl-tutor-panel__quota-count {
  color: #00f2ff;
  font-weight: 600;
}

.fl-tutor-panel__quota-count--low {
  color: #ff9f43;
}

.fl-tutor-panel__quota-count--empty {
  color: #ff4d4d;
}

/* 对话区域 */
.fl-tutor-panel__messages {
  flex: 1;
  overflow-y: auto;
  padding: 16px 14px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  scrollbar-width: thin;
  scrollbar-color: rgba(0, 242, 255, 0.2) transparent;
}

.fl-tutor-panel__messages::-webkit-scrollbar {
  width: 4px;
}

.fl-tutor-panel__messages::-webkit-scrollbar-thumb {
  background: rgba(0, 242, 255, 0.15);
  border-radius: 2px;
}

/* 欢迎提示 */
.fl-tutor-panel__welcome {
  text-align: center;
  padding: 30px 20px;
  color: #64748b;
}

.fl-tutor-panel__welcome-icon {
  font-size: 48px;
  margin-bottom: 12px;
  opacity: 0.5;
}

.fl-tutor-panel__welcome-text {
  font-size: 14px;
  line-height: 1.6;
}

/* 消息气泡 */
.fl-msg {
  max-width: 85%;
  padding: 10px 14px;
  border-radius: 12px;
  font-size: 14px;
  line-height: 1.6;
  word-break: break-word;
  position: relative;
  animation: fl-msg-fade-in 0.3s ease;
}

@keyframes fl-msg-fade-in {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

.fl-msg--user {
  align-self: flex-end;
  background: linear-gradient(135deg, rgba(0, 242, 255, 0.15), rgba(0, 242, 255, 0.08));
  border: 1px solid rgba(0, 242, 255, 0.2);
  color: #e0f7fa;
  border-bottom-right-radius: 4px;
}

.fl-msg--ai {
  align-self: flex-start;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.08);
  color: #e2e8f0;
  border-bottom-left-radius: 4px;
}

.fl-msg--socratic {
  border-color: rgba(255, 213, 79, 0.3);
  background: rgba(255, 213, 79, 0.06);
}

.fl-msg--socratic::before {
  content: '💡 ';
}

.fl-msg__content {
  white-space: pre-wrap;
}

.fl-msg__content p {
  margin: 0 0 6px 0;
}

.fl-msg__content p:last-child {
  margin-bottom: 0;
}

/* LaTeX公式渲染 */
.fl-msg__content .katex {
  font-size: 1.05em;
}

/* 引用来源 */
.fl-msg__citations {
  margin-top: 8px;
  padding-top: 8px;
  border-top: 1px dashed rgba(0, 242, 255, 0.15);
}

.fl-msg__citations-title {
  font-size: 11px;
  color: #64748b;
  margin-bottom: 4px;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 4px;
}

.fl-msg__citations-title:hover {
  color: #00f2ff;
}

.fl-msg__citations-list {
  display: none;
  gap: 6px;
  flex-direction: column;
}

.fl-msg__citations-list--expanded {
  display: flex;
}

.fl-citation-card {
  padding: 6px 10px;
  background: rgba(0, 242, 255, 0.04);
  border: 1px solid rgba(0, 242, 255, 0.1);
  border-radius: 6px;
  font-size: 12px;
  color: #94a3b8;
}

.fl-citation-card__source {
  color: #00f2ff;
  font-weight: 500;
}

.fl-citation-card__snippet {
  margin-top: 2px;
  color: #64748b;
  line-height: 1.4;
}

/* 关联节点 */
.fl-msg__related-nodes {
  margin-top: 8px;
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
}

.fl-related-node {
  padding: 2px 8px;
  background: rgba(0, 242, 255, 0.08);
  border: 1px solid rgba(0, 242, 255, 0.15);
  border-radius: 10px;
  font-size: 11px;
  color: #00f2ff;
  cursor: pointer;
  text-decoration: none;
  transition: all 0.2s;
}

.fl-related-node:hover {
  background: rgba(0, 242, 255, 0.2);
  text-decoration: underline;
}

/* 反馈按钮 */
.fl-msg__feedback {
  margin-top: 6px;
  display: flex;
  gap: 8px;
}

.fl-feedback-btn {
  padding: 2px 8px;
  border: 1px solid rgba(255, 255, 255, 0.1);
  background: transparent;
  color: #64748b;
  border-radius: 4px;
  font-size: 11px;
  cursor: pointer;
  transition: all 0.2s;
}

.fl-feedback-btn:hover {
  border-color: rgba(0, 242, 255, 0.3);
  color: #00f2ff;
}

.fl-feedback-btn--active {
  background: rgba(0, 242, 255, 0.1);
  border-color: rgba(0, 242, 255, 0.3);
  color: #00f2ff;
}

/* 加载动画 */
.fl-msg__loading {
  display: flex;
  align-items: center;
  gap: 4px;
  padding: 12px 16px;
}

.fl-loading-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: #00f2ff;
  animation: fl-loading-bounce 1.4s infinite ease-in-out both;
}

.fl-loading-dot:nth-child(1) { animation-delay: -0.32s; }
.fl-loading-dot:nth-child(2) { animation-delay: -0.16s; }

@keyframes fl-loading-bounce {
  0%, 80%, 100% { transform: scale(0); }
  40% { transform: scale(1); }
}

/* 输入区域 */
.fl-tutor-panel__input-area {
  padding: 12px 14px;
  border-top: 1px solid rgba(255, 255, 255, 0.06);
  flex-shrink: 0;
  display: flex;
  gap: 8px;
  align-items: flex-end;
}

.fl-tutor-panel__input {
  flex: 1;
  background: rgba(0, 0, 0, 0.3);
  border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 8px;
  padding: 10px 14px;
  color: #e2e8f0;
  font-size: 14px;
  font-family: inherit;
  resize: none;
  max-height: 100px;
  min-height: 40px;
  transition: border-color 0.2s;
  outline: none;
}

.fl-tutor-panel__input:focus {
  border-color: rgba(0, 242, 255, 0.4);
  box-shadow: 0 0 0 2px rgba(0, 242, 255, 0.1);
}

.fl-tutor-panel__input::placeholder {
  color: #475569;
}

.fl-tutor-panel__send {
  width: 40px;
  height: 40px;
  border: none;
  border-radius: 8px;
  background: linear-gradient(135deg, #00f2ff, #00b8d4);
  color: #000;
  font-size: 18px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.2s;
  flex-shrink: 0;
}

.fl-tutor-panel__send:hover {
  transform: scale(1.05);
  box-shadow: 0 4px 12px rgba(0, 242, 255, 0.3);
}

.fl-tutor-panel__send:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none;
}

/* 触发按钮 (常驻在页面上) */
.fl-tutor-trigger {
  position: fixed;
  right: 20px;
  bottom: 80px;
  width: 52px;
  height: 52px;
  border-radius: 50%;
  background: linear-gradient(135deg, #00f2ff, #00b8d4);
  border: 2px solid rgba(0, 242, 255, 0.3);
  color: #000;
  font-size: 24px;
  cursor: pointer;
  z-index: 99999;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 20px rgba(0, 242, 255, 0.3);
  transition: all 0.3s;
  animation: fl-trigger-pulse 3s infinite;
}

.fl-tutor-trigger:hover {
  transform: scale(1.1);
  box-shadow: 0 6px 28px rgba(0, 242, 255, 0.5);
}

@keyframes fl-trigger-pulse {
  0%, 100% { box-shadow: 0 4px 20px rgba(0, 242, 255, 0.3); }
  50% { box-shadow: 0 4px 20px rgba(0, 242, 255, 0.15); }
}

/* 移动端适配 */
@media (max-width: 768px) {
  .fl-tutor-panel {
    width: 100%;
    right: -100%;
  }

  .fl-tutor-panel--open {
    right: 0;
  }

  .fl-tutor-trigger {
    right: 16px;
    bottom: 70px;
    width: 46px;
    height: 46px;
    font-size: 20px;
  }
}

/* ===== 消息删除按钮 (07-07) ===== */
.fl-msg__delete {
  position: absolute;
  top: 4px;
  right: 6px;
  width: 20px;
  height: 20px;
  line-height: 18px;
  text-align: center;
  padding: 0;
  border: none;
  border-radius: 50%;
  background: rgba(0, 0, 0, 0.25);
  color: #ff6b6b;
  font-size: 12px;
  cursor: pointer;
  opacity: 0;
  transition: opacity 0.15s ease, background 0.15s ease, transform 0.15s ease;
  z-index: 2;
}
.fl-msg:hover .fl-msg__delete {
  opacity: 0.75;
}
.fl-msg__delete:hover {
  opacity: 1;
  background: rgba(255, 107, 107, 0.85);
  color: #fff;
  transform: scale(1.1);
}
/* 触屏设备无 hover, 常显淡色以便点击 */
@media (hover: none) {
  .fl-msg__delete { opacity: 0.5; }
}