/* Chat RAG view */
    .chat-view-layout { display: flex; flex: 1; overflow: hidden; }
    .chat-left {
      width: 26%; min-width: 220px; max-width: 340px;
      border-right: 1px solid var(--border);
      overflow-y: auto; padding: 20px 16px; flex-shrink: 0;
    }
    .chat-right { flex: 1; display: flex; flex-direction: column; overflow: hidden; min-width: 0; }
    .chat-messages {
      flex: 1; overflow-y: auto; padding: 20px;
      display: flex; flex-direction: column; gap: 14px;
    }
    .chat-msg { max-width: 86%; display: flex; flex-direction: column; gap: 4px; }
    .chat-msg.user { align-self: flex-end; align-items: flex-end; }
    .chat-msg.assistant { align-self: flex-start; }
    .chat-bubble {
      padding: 10px 14px; border-radius: var(--radius-lg);
      font-size: 14px; line-height: 1.65;
    }
    .chat-msg.user .chat-bubble {
      background: var(--accent); color: #0a1a12;
      border-bottom-right-radius: 4px;
    }
    .chat-msg.assistant .chat-bubble {
      background: var(--surface2); color: var(--text);
      border-bottom-left-radius: 4px;
    }
    .chat-sources {
      font-size: 11px; color: var(--muted); padding: 2px 4px;
    }
    .chat-ooc {
      display: flex; flex-direction: column; gap: 10px;
      padding: 12px 14px; background: var(--surface2);
      border: 1px solid var(--border); border-radius: var(--radius-lg);
      border-bottom-left-radius: 4px; font-size: 14px; color: var(--text-soft);
      max-width: 86%; align-self: flex-start;
    }
    .chat-ooc-btns { display: flex; gap: 8px; flex-wrap: wrap; }
    .chat-ooc-btn {
      padding: 5px 12px; border-radius: 20px;
      border: 1px solid var(--border); background: var(--surface3);
      color: var(--text); font-size: 12px; cursor: pointer;
      transition: background var(--t-fast);
    }
    .chat-ooc-btn:hover { background: var(--border-hover); }
    .chat-starters {
      display: flex; flex-direction: column; gap: 8px;
      padding: 12px 16px; border-top: 1px solid var(--border);
    }
    .chat-starter-lbl { font-size: 11px; color: var(--muted); text-transform: uppercase; letter-spacing: .04em; }
    .chat-starter-btn {
      text-align: left; padding: 9px 12px;
      border-radius: var(--radius-md); border: 1px solid var(--border);
      background: var(--surface2); color: var(--text-soft);
      font-size: 13px; cursor: pointer; line-height: 1.5;
      transition: border-color var(--t-fast), color var(--t-fast);
    }
    .chat-starter-btn:hover { border-color: var(--accent); color: var(--text); }
    .chat-input-bar {
      display: flex; align-items: flex-end; gap: 8px;
      padding: 10px 14px; border-top: 1px solid var(--border); flex-shrink: 0;
    }
    .chat-input {
      flex: 1; resize: none; min-height: 38px; max-height: 110px;
      padding: 9px 12px; background: var(--surface2);
      border: 1px solid var(--border); border-radius: var(--radius-md);
      color: var(--text); font-family: var(--font-sans); font-size: 14px;
      line-height: 1.5; overflow-y: auto;
    }
    .chat-input:focus { outline: none; border-color: var(--accent); }
    .chat-input::placeholder { color: var(--muted); }
    .chat-send-btn {
      width: 36px; height: 36px; border-radius: var(--radius-md);
      border: none; background: var(--accent); color: #0a1a12;
      cursor: pointer; display: flex; align-items: center; justify-content: center;
      flex-shrink: 0; transition: opacity var(--t-fast);
    }
    .chat-send-btn:hover { opacity: 0.85; }
    .chat-send-btn:disabled { opacity: 0.35; cursor: default; pointer-events: none; }
    .chat-quiz-bar {
      display: flex; justify-content: center;
      padding: 8px; border-top: 1px solid var(--border); flex-shrink: 0;
    }
    .chat-quiz-btn {
      padding: 6px 16px; border-radius: 20px;
      border: 1px solid var(--border); background: transparent;
      color: var(--text-soft); font-size: 12px; cursor: pointer;
      transition: color var(--t-fast), border-color var(--t-fast);
    }
    .chat-quiz-btn:hover { color: var(--accent); border-color: var(--accent); }
    .chat-thinking {
      display: flex; gap: 5px; padding: 10px 14px;
      background: var(--surface2); border-radius: var(--radius-lg);
      align-self: flex-start; border-bottom-left-radius: 4px;
    }
    .chat-thinking span {
      width: 6px; height: 6px; border-radius: 50%;
      background: var(--muted); animation: chatDot 1.2s infinite ease-in-out;
    }
    .chat-thinking span:nth-child(2) { animation-delay: .2s; }
    .chat-thinking span:nth-child(3) { animation-delay: .4s; }
    @keyframes chatDot {
      0%,80%,100% { transform: scale(.6); opacity: .4; }
      40%          { transform: scale(1);  opacity: 1; }
    }
    /* Quiz modal */
    .quiz-overlay {
      position: fixed; inset: 0; background: rgba(0,0,0,.65);
      z-index: 5000; display: flex; align-items: center; justify-content: center; padding: 20px;
    }
    .quiz-modal {
      background: var(--surface); border: 1px solid var(--border);
      border-radius: var(--radius-xl); max-width: 540px; width: 100%;
      padding: 24px; display: flex; flex-direction: column; gap: 16px;
      max-height: 80vh; overflow-y: auto;
    }
    .quiz-progress { font-size: 11px; color: var(--muted); }
    .quiz-q { font-size: 15px; font-weight: 600; color: var(--text); line-height: 1.5; }
    .quiz-opts { display: flex; flex-direction: column; gap: 8px; }
    .quiz-opt {
      padding: 10px 14px; border-radius: var(--radius-md);
      border: 1px solid var(--border); background: var(--surface2);
      color: var(--text); font-size: 14px; cursor: pointer; text-align: left;
      transition: border-color var(--t-fast);
    }
    .quiz-opt:hover:not(:disabled) { border-color: var(--accent); }
    .quiz-opt.correct  { border-color: var(--accent); background: var(--accent-bg); }
    .quiz-opt.wrong    { border-color: var(--danger);  background: var(--danger-bg); }
    .quiz-fb { font-size: 13px; min-height: 18px; }
    .quiz-actions { display: flex; gap: 10px; flex-wrap: wrap; }
    .quiz-next-btn {
      padding: 9px 18px; border-radius: var(--radius-md); border: none;
      background: var(--accent); color: #0a1a12; font-size: 14px;
      font-weight: 600; cursor: pointer;
    }
    .quiz-close-btn {
      padding: 9px 18px; border-radius: var(--radius-md);
      border: 1px solid var(--border); background: transparent;
      color: var(--text-soft); font-size: 14px; cursor: pointer;
    }
    /* Course left panel */
    .chat-left-block { border: 1px solid var(--border); border-radius: var(--radius-md); margin-bottom: 10px; overflow: hidden; }
    .chat-left-hdr {
      padding: 6px 10px; background: var(--surface2); border-bottom: 1px solid var(--border);
      font-size: 11px; color: var(--muted); display: flex; justify-content: space-between;
    }
    .chat-left-body {
      padding: 10px; font-size: 12px; line-height: 1.65; color: var(--text-soft);
      white-space: pre-wrap; cursor: pointer;
    }
    .chat-left-body:hover { color: var(--text); }
    @media (max-width: 768px) { .chat-left { display: none; } }