feat(study): 문제풀이 세션 + 결과 카드 + 학습완료 체크 (PR-10)

- study_quiz_sessions 테이블 (한 토픽 in_progress 1개 partial unique) - study_question_attempts 에 quiz_session_id + reviewed_at 컬럼 - 풀이 진행률 서버 단일 진실 (cursor) — 나갔다 와도 이어풀기 가능 - 통합뷰: 진행 중 카드(이어풀기) + 최근 완료 결과 카드(미확인 N건 배지) - 신규 /quiz-sessions/[sid] 결과 페이지 (3 카테고리 + AI 해설 + 분야 설명 + 학습완료 토글) - /review 페이지는 풀이만, 마지막 문제 풀이 후 결과 페이지로 redirect - 마이그레이션 206~209 (single-statement, asyncpg 호환) - API: POST/GET/PATCH /study-topics/{tid}/quiz-sessions(/{sid}), PATCH /study-question-attempts/{aid}/review-mark - AttemptCreate.quiz_session_id 추가 — submit_attempt 가 같은 트랜잭션에서 세션 cursor + count 증가, 마지막이면 status='done' + finished_at Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-04-28 16:49:21 +09:00
parent d968b2d901
commit 7f4d64c6df
11 changed files with 1332 additions and 437 deletions
@@ -27,6 +27,7 @@ from core.config import settings
 from core.database import get_session
 from models.study_question import StudyQuestion, StudyQuestionAttempt
 from models.study_question_image import StudyQuestionImage
+from models.study_quiz_session import StudyQuizSession
 from models.study_topic import StudyTopic
 from models.user import User
 from services.search.llm_gate import get_mlx_gate
@@ -190,18 +191,25 @@ class ReviewQuestionListResponse(BaseModel):
 class AttemptCreate(BaseModel):
    """PR-9: selected_choice (1~4) 또는 is_unsure 둘 중 하나 필수.
    is_unsure=true 면 selected_choice 무시 + outcome='unsure' 로 박힘.
+    PR-10: quiz_session_id 전달 시 세션의 cursor + count 도 함께 갱신.
    """
    selected_choice: int | None = Field(default=None, ge=1, le=4)
    is_unsure: bool = False
+    quiz_session_id: int | None = None


 class AttemptResponse(BaseModel):
+    id: int  # PR-10: 학습완료 토글 시 attempt 단위로 PATCH 하므로 id 노출 필요.
    is_correct: bool
    selected_choice: int | None
    correct_choice: int
    outcome: str  # PR-9: correct | wrong | unsure
    explanation: str | None
    stats: QuestionAttemptStats
+    quiz_session_id: int | None = None
+    quiz_session_status: str | None = None  # in_progress | done (마지막 문제면 done 으로 박힘)
+    quiz_session_cursor: int | None = None
+    reviewed_at: datetime | None = None


 # ─── PR-5: 비슷한 문제 검색 (embedding cosine) ───
@@ -837,6 +845,8 @@ async def submit_attempt(
 ):
    """답 제출. PR-9: is_unsure=true 면 outcome='unsure' + selected_choice=NULL.
    그 외엔 selected_choice 와 correct_choice 비교 → outcome='correct'/'wrong'.
+    PR-10: quiz_session_id 전달 시 같은 트랜잭션에서 세션 cursor + count 도 갱신.
+    cursor 가 question_ids 끝까지 도달하면 status='done', finished_at 박힘.
    """
    q = await session.get(StudyQuestion, question_id)
    q = _verify_question_ownership(q, user)
@@ -855,6 +865,32 @@ async def submit_attempt(
        is_correct = selected == q.correct_choice
        outcome = "correct" if is_correct else "wrong"

+    # PR-10: 세션 연동. 기본은 None.
+    quiz_session: StudyQuizSession | None = None
+    if body.quiz_session_id is not None:
+        quiz_session = await session.get(StudyQuizSession, body.quiz_session_id)
+        if quiz_session is None or quiz_session.user_id != user.id:
+            raise HTTPException(status_code=404, detail="quiz_session 을 찾을 수 없습니다")
+        if quiz_session.study_topic_id != q.study_topic_id:
+            raise HTTPException(
+                status_code=400,
+                detail="quiz_session 의 토픽과 문제의 토픽이 다릅니다",
+            )
+        if quiz_session.status != "in_progress":
+            raise HTTPException(
+                status_code=409,
+                detail=f"quiz_session 상태가 {quiz_session.status} — 이미 종료된 세션입니다",
+            )
+        # 현재 cursor 위치의 문제와 일치해야만 진행 (out-of-order 제출 차단).
+        qids = quiz_session.question_ids or []
+        if quiz_session.cursor >= len(qids):
+            raise HTTPException(status_code=409, detail="이미 모든 문제를 풀었습니다")
+        if qids[quiz_session.cursor] != q.id:
+            raise HTTPException(
+                status_code=409,
+                detail="현재 cursor 위치의 문제와 question_id 가 일치하지 않습니다 (이중 제출/순서 어긋남)",
+            )
+
    attempt = StudyQuestionAttempt(
        user_id=user.id,
        study_question_id=q.id,
@@ -863,21 +899,73 @@ async def submit_attempt(
        correct_choice=q.correct_choice,
        is_correct=is_correct,
        outcome=outcome,
+        quiz_session_id=quiz_session.id if quiz_session else None,
    )
    session.add(attempt)
+
+    if quiz_session is not None:
+        quiz_session.cursor = quiz_session.cursor + 1
+        if outcome == "correct":
+            quiz_session.correct_count += 1
+        elif outcome == "wrong":
+            quiz_session.wrong_count += 1
+        elif outcome == "unsure":
+            quiz_session.unsure_count += 1
+        if quiz_session.cursor >= len(quiz_session.question_ids or []):
+            quiz_session.status = "done"
+            quiz_session.finished_at = datetime.now(timezone.utc)
+        quiz_session.updated_at = datetime.now(timezone.utc)
+
    await session.commit()
+    await session.refresh(attempt)

    stats = await _attempt_stats(session, user.id, question_id)
    return AttemptResponse(
+        id=attempt.id,
        is_correct=is_correct,
        selected_choice=selected,
        correct_choice=q.correct_choice,
        outcome=outcome,
        explanation=q.explanation,
        stats=stats,
+        quiz_session_id=quiz_session.id if quiz_session else None,
+        quiz_session_status=quiz_session.status if quiz_session else None,
+        quiz_session_cursor=quiz_session.cursor if quiz_session else None,
+        reviewed_at=attempt.reviewed_at,
    )


+# ─── PR-10: 학습완료 토글 ───
+
+
+class AttemptReviewRequest(BaseModel):
+    reviewed: bool
+
+
+class AttemptReviewResponse(BaseModel):
+    id: int
+    reviewed_at: datetime | None
+
+
+@router.patch(
+    "/study-question-attempts/{attempt_id}/review-mark",
+    response_model=AttemptReviewResponse,
+)
+async def mark_attempt_reviewed(
+    attempt_id: int,
+    body: AttemptReviewRequest,
+    user: Annotated[User, Depends(get_current_user)],
+    session: Annotated[AsyncSession, Depends(get_session)],
+):
+    """결과 카드에서 [학습완료] 토글. reviewed=true 면 timestamp, false 면 NULL."""
+    attempt = await session.get(StudyQuestionAttempt, attempt_id)
+    if attempt is None or attempt.user_id != user.id:
+        raise HTTPException(status_code=404, detail="attempt 를 찾을 수 없습니다")
+    attempt.reviewed_at = datetime.now(timezone.utc) if body.reviewed else None
+    await session.commit()
+    return AttemptReviewResponse(id=attempt.id, reviewed_at=attempt.reviewed_at)
+
+
 # ─── PR-5: 비슷한 문제 검색 (embedding cosine) ───


@@ -17,13 +17,14 @@

 import asyncio
 import logging
+import random as _random
 from datetime import datetime, timezone
 from pathlib import Path as _Path
 from typing import Annotated, Any

 from fastapi import APIRouter, Depends, HTTPException, Query
 from pydantic import BaseModel, Field
-from sqlalchemy import and_, delete, func, select, text as sql_text, update
+from sqlalchemy import and_, case, delete, func, select, text as sql_text, update
 from sqlalchemy.exc import IntegrityError
 from sqlalchemy.ext.asyncio import AsyncSession

@@ -34,6 +35,9 @@ from core.library import LIBRARY_PREFIX, normalize_library_path
 from models.document import Document
 from models.study_session import StudySession
 from models.study_topic import StudyTopic, StudyTopicDocument
+from models.study_question import StudyQuestion, StudyQuestionAttempt
+from models.study_question_image import StudyQuestionImage
+from models.study_quiz_session import StudyQuizSession
 from models.study_topic_subject_note import StudyTopicSubjectNote
 from models.user import User
 from services.search.llm_gate import get_mlx_gate
@@ -1210,3 +1214,454 @@ async def generate_subject_note(
        evidence=[e.to_dict() for e in ctx.all],
        from_cache=False, can_regenerate=True,
    )
+
+
+# ─── PR-10: 문제풀이 세션 (quiz_session) lifecycle ───
+#
+# 한 토픽당 in_progress 1개. 출제 시 session 행 생성 + question_ids 스냅샷.
+# 풀이 중 attempt 마다 cursor + count 증가 (study_questions.submit_attempt 가 같은 트랜잭션에서).
+# 마지막 문제 풀이 후 status='done' + finished_at 박힘.
+
+
+class QuizSessionStartRequest(BaseModel):
+    target_per_subject: int = Field(default=20, ge=1, le=100)
+    subject: str | None = Field(default=None, max_length=120)
+    scope: str | None = Field(default=None, max_length=200)
+    wrong_only: bool = False
+    abandon_existing: bool = False  # true 면 기존 in_progress 세션을 abandoned 로 마감 후 새로
+
+
+class QuizSessionSummary(BaseModel):
+    """진행 카드 + 결과 카드 공통 (가벼운 메타). 문제 본문은 상세 endpoint 에서."""
+    id: int
+    status: str
+    cursor: int
+    total: int
+    correct_count: int
+    wrong_count: int
+    unsure_count: int
+    target_per_subject: int
+    subject_filter: str | None
+    wrong_only: bool
+    subject_distribution: dict
+    created_at: datetime
+    updated_at: datetime
+    finished_at: datetime | None
+    # 결과 카드 헤더 "미확인 N건" 용 — done 세션에서만 의미.
+    unreviewed_wrong_unsure_count: int = 0
+
+
+class QuizSessionListResponse(BaseModel):
+    active: QuizSessionSummary | None
+    recent_done: list[QuizSessionSummary]
+
+
+async def _build_session_summary(
+    s: StudyQuizSession,
+    session: AsyncSession,
+) -> QuizSessionSummary:
+    """status='done' 일 때 미확인 카운트(reviewed_at NULL + outcome IN wrong/unsure) 계산."""
+    unreviewed = 0
+    if s.status == "done":
+        row = (
+            await session.execute(
+                select(func.count())
+                .select_from(StudyQuestionAttempt)
+                .where(
+                    StudyQuestionAttempt.quiz_session_id == s.id,
+                    StudyQuestionAttempt.outcome.in_(("wrong", "unsure")),
+                    StudyQuestionAttempt.reviewed_at.is_(None),
+                )
+            )
+        ).scalar() or 0
+        unreviewed = int(row)
+    return QuizSessionSummary(
+        id=s.id,
+        status=s.status,
+        cursor=s.cursor,
+        total=len(s.question_ids or []),
+        correct_count=s.correct_count,
+        wrong_count=s.wrong_count,
+        unsure_count=s.unsure_count,
+        target_per_subject=s.target_per_subject,
+        subject_filter=s.subject_filter,
+        wrong_only=s.wrong_only,
+        subject_distribution=s.subject_distribution or {},
+        created_at=s.created_at,
+        updated_at=s.updated_at,
+        finished_at=s.finished_at,
+        unreviewed_wrong_unsure_count=unreviewed,
+    )
+
+
+async def _select_questions_for_topic(
+    session: AsyncSession,
+    user: User,
+    topic_id: int,
+    *,
+    subject: str | None,
+    scope: str | None,
+    target_per_subject: int,
+    wrong_only: bool,
+) -> tuple[list[int], dict[str, int]]:
+    """과목별 균등 추출 (study_questions.review_questions_for_topic 의 동일 로직).
+    출제 후 셔플된 question_id list + subject_distribution 반환.
+    """
+    base_filter = and_(
+        StudyQuestion.user_id == user.id,
+        StudyQuestion.study_topic_id == topic_id,
+        StudyQuestion.deleted_at.is_(None),
+        StudyQuestion.is_active.is_(True),
+    )
+
+    wrong_qids: set[int] | None = None
+    if wrong_only:
+        latest = (
+            await session.execute(
+                select(
+                    StudyQuestionAttempt.study_question_id,
+                    StudyQuestionAttempt.is_correct,
+                )
+                .where(
+                    StudyQuestionAttempt.user_id == user.id,
+                    StudyQuestionAttempt.study_topic_id == topic_id,
+                )
+                .order_by(
+                    StudyQuestionAttempt.study_question_id,
+                    StudyQuestionAttempt.answered_at.desc(),
+                )
+                .distinct(StudyQuestionAttempt.study_question_id)
+            )
+        ).all()
+        wrong_qids = {r.study_question_id for r in latest if r.is_correct is False}
+        if not wrong_qids:
+            return [], {}
+
+    if subject is not None:
+        subjects: list[str | None] = [subject]
+    else:
+        subj_query = (
+            select(StudyQuestion.subject)
+            .where(base_filter)
+            .distinct()
+        )
+        if scope is not None:
+            subj_query = subj_query.where(StudyQuestion.scope == scope)
+        if wrong_qids is not None:
+            subj_query = subj_query.where(StudyQuestion.id.in_(wrong_qids))
+        subjects = [r[0] for r in (await session.execute(subj_query)).all()]
+        if not subjects:
+            return [], {}
+
+    selected_ids: list[int] = []
+    distribution: dict[str, int] = {}
+    for subj in subjects:
+        sub_q = select(StudyQuestion.id).where(base_filter)
+        if subj is None:
+            sub_q = sub_q.where(StudyQuestion.subject.is_(None))
+        else:
+            sub_q = sub_q.where(StudyQuestion.subject == subj)
+        if scope is not None:
+            sub_q = sub_q.where(StudyQuestion.scope == scope)
+        if wrong_qids is not None:
+            sub_q = sub_q.where(StudyQuestion.id.in_(wrong_qids))
+        sub_q = sub_q.order_by(func.random()).limit(target_per_subject)
+        rows = [r for (r,) in (await session.execute(sub_q)).all()]
+        if rows:
+            selected_ids.extend(rows)
+            distribution[subj or ""] = len(rows)
+
+    _random.shuffle(selected_ids)
+    return selected_ids, distribution
+
+
+@router.get("/{topic_id}/quiz-sessions", response_model=QuizSessionListResponse)
+async def list_quiz_sessions(
+    topic_id: int,
+    user: Annotated[User, Depends(get_current_user)],
+    session: Annotated[AsyncSession, Depends(get_session)],
+    limit: int = Query(20, ge=1, le=100),
+):
+    """진행 중 + 최근 완료 N건. 통합뷰 진행/결과 카드용."""
+    topic = await session.get(StudyTopic, topic_id)
+    _verify_topic_ownership(topic, user)
+
+    active_row = (
+        await session.execute(
+            select(StudyQuizSession).where(
+                StudyQuizSession.user_id == user.id,
+                StudyQuizSession.study_topic_id == topic_id,
+                StudyQuizSession.status == "in_progress",
+            )
+        )
+    ).scalar_one_or_none()
+    active_summary = await _build_session_summary(active_row, session) if active_row else None
+
+    done_rows = (
+        await session.execute(
+            select(StudyQuizSession)
+            .where(
+                StudyQuizSession.user_id == user.id,
+                StudyQuizSession.study_topic_id == topic_id,
+                StudyQuizSession.status == "done",
+            )
+            .order_by(StudyQuizSession.finished_at.desc().nulls_last())
+            .limit(limit)
+        )
+    ).scalars().all()
+    done = [await _build_session_summary(s, session) for s in done_rows]
+
+    return QuizSessionListResponse(active=active_summary, recent_done=done)
+
+
+@router.post("/{topic_id}/quiz-sessions", response_model=QuizSessionSummary, status_code=201)
+async def start_quiz_session(
+    topic_id: int,
+    body: QuizSessionStartRequest,
+    user: Annotated[User, Depends(get_current_user)],
+    session: Annotated[AsyncSession, Depends(get_session)],
+):
+    """새 세션 시작. 기존 in_progress 가 있으면:
+       - body.abandon_existing=false → 기존 세션 그대로 반환 (이어풀기).
+       - body.abandon_existing=true → 기존을 abandoned 로 마감 후 새로 출제.
+    """
+    topic = await session.get(StudyTopic, topic_id)
+    _verify_topic_ownership(topic, user)
+
+    existing = (
+        await session.execute(
+            select(StudyQuizSession).where(
+                StudyQuizSession.user_id == user.id,
+                StudyQuizSession.study_topic_id == topic_id,
+                StudyQuizSession.status == "in_progress",
+            )
+        )
+    ).scalar_one_or_none()
+
+    if existing is not None:
+        if not body.abandon_existing:
+            # 이어풀기 — 기존 그대로 반환.
+            return await _build_session_summary(existing, session)
+        existing.status = "abandoned"
+        existing.updated_at = datetime.now(timezone.utc)
+        await session.flush()
+
+    # 신규 출제.
+    qids, distribution = await _select_questions_for_topic(
+        session,
+        user,
+        topic_id,
+        subject=body.subject,
+        scope=body.scope,
+        target_per_subject=body.target_per_subject,
+        wrong_only=body.wrong_only,
+    )
+    if not qids:
+        raise HTTPException(status_code=400, detail="출제 가능한 문제가 없습니다")
+
+    new_session = StudyQuizSession(
+        user_id=user.id,
+        study_topic_id=topic_id,
+        target_per_subject=body.target_per_subject,
+        subject_filter=body.subject,
+        wrong_only=body.wrong_only,
+        question_ids=qids,
+        subject_distribution=distribution,
+        status="in_progress",
+        cursor=0,
+    )
+    session.add(new_session)
+    try:
+        await session.commit()
+    except IntegrityError:
+        # partial unique idx 충돌 — 동시에 다른 호출이 in_progress 만든 경우.
+        await session.rollback()
+        existing = (
+            await session.execute(
+                select(StudyQuizSession).where(
+                    StudyQuizSession.user_id == user.id,
+                    StudyQuizSession.study_topic_id == topic_id,
+                    StudyQuizSession.status == "in_progress",
+                )
+            )
+        ).scalar_one_or_none()
+        if existing is None:
+            raise HTTPException(status_code=409, detail="quiz_session 충돌 — 다시 시도하세요")
+        return await _build_session_summary(existing, session)
+
+    return await _build_session_summary(new_session, session)
+
+
+class QuizSessionAttemptItem(BaseModel):
+    """결과 카드 expand 시 카드별 메타 (attempt + 학습완료 상태)."""
+    attempt_id: int
+    question_id: int
+    selected_choice: int | None
+    correct_choice: int
+    outcome: str
+    answered_at: datetime
+    reviewed_at: datetime | None
+
+
+class QuizSessionDetailResponse(BaseModel):
+    summary: QuizSessionSummary
+    questions: list[dict]  # ReviewQuestionItem 호환 shape
+    attempts: list[QuizSessionAttemptItem]  # 풀이된 것만 (cursor 까지)
+
+
+def _attempt_stats_dict_default() -> dict:
+    return {"attempt_count": 0, "correct_count": 0, "wrong_count": 0}
+
+
+@router.get("/{topic_id}/quiz-sessions/{session_id}", response_model=QuizSessionDetailResponse)
+async def get_quiz_session(
+    topic_id: int,
+    session_id: int,
+    user: Annotated[User, Depends(get_current_user)],
+    session: Annotated[AsyncSession, Depends(get_session)],
+):
+    """풀이 화면 / 결과 화면 공용. questions 는 출제 순서. attempts 는 cursor 까지 풀이된 것만."""
+    topic = await session.get(StudyTopic, topic_id)
+    _verify_topic_ownership(topic, user)
+
+    qs = await session.get(StudyQuizSession, session_id)
+    if qs is None or qs.user_id != user.id or qs.study_topic_id != topic_id:
+        raise HTTPException(status_code=404, detail="quiz_session 을 찾을 수 없습니다")
+
+    qids = list(qs.question_ids or [])
+    questions_payload: list[dict] = []
+    if qids:
+        rows = (
+            await session.execute(
+                select(StudyQuestion).where(StudyQuestion.id.in_(qids))
+            )
+        ).scalars().all()
+        by_id = {q.id: q for q in rows}
+
+        # 이미지 batch
+        img_rows = (
+            await session.execute(
+                select(StudyQuestionImage)
+                .where(StudyQuestionImage.study_question_id.in_(qids))
+                .order_by(StudyQuestionImage.study_question_id, StudyQuestionImage.position)
+            )
+        ).scalars().all()
+        images_map: dict[int, list[dict]] = {}
+        for im in img_rows:
+            images_map.setdefault(im.study_question_id, []).append({
+                "id": im.id,
+                "served_url": f"/api/study-questions/{im.study_question_id}/images/{im.id}",
+                "position": im.position,
+            })
+
+        # attempt count batch (per question)
+        stat_rows = (
+            await session.execute(
+                select(
+                    StudyQuestionAttempt.study_question_id,
+                    func.count().label("total"),
+                    func.coalesce(
+                        func.sum(case((StudyQuestionAttempt.is_correct.is_(True), 1), else_=0)),
+                        0,
+                    ).label("correct"),
+                )
+                .where(
+                    StudyQuestionAttempt.user_id == user.id,
+                    StudyQuestionAttempt.study_question_id.in_(qids),
+                )
+                .group_by(StudyQuestionAttempt.study_question_id)
+            )
+        ).all()
+        stats_map: dict[int, dict] = {}
+        for r in stat_rows:
+            t = int(r.total)
+            c = int(r.correct)
+            stats_map[r.study_question_id] = {
+                "attempt_count": t, "correct_count": c, "wrong_count": t - c
+            }
+
+        # 출제 순서 그대로 nest
+        for qid in qids:
+            q = by_id.get(qid)
+            if q is None:
+                continue
+            questions_payload.append({
+                "id": q.id,
+                "question_text": q.question_text,
+                "choices": [
+                    {"number": 1, "text": q.choice_1},
+                    {"number": 2, "text": q.choice_2},
+                    {"number": 3, "text": q.choice_3},
+                    {"number": 4, "text": q.choice_4},
+                ],
+                "subject": q.subject,
+                "scope": q.scope,
+                "exam_round": q.exam_round,
+                "explanation": q.explanation,
+                "stats": stats_map.get(q.id, _attempt_stats_dict_default()),
+                "images": images_map.get(q.id, []),
+                # done 세션 결과 화면용 — 정답 노출. in_progress 세션은 클라이언트가 cursor 까지만 표시.
+                "correct_choice": q.correct_choice if qs.status == "done" else None,
+            })
+
+    # 이 세션의 attempts (cursor 까지). 같은 question 에 여러 attempts 있을 수 있지만,
+    # 이 세션 내에서는 정상 흐름상 question 당 1개. quiz_session_id 기준으로 가져옴.
+    attempt_rows = (
+        await session.execute(
+            select(StudyQuestionAttempt)
+            .where(
+                StudyQuestionAttempt.user_id == user.id,
+                StudyQuestionAttempt.quiz_session_id == qs.id,
+            )
+            .order_by(StudyQuestionAttempt.answered_at.asc())
+        )
+    ).scalars().all()
+    attempts_payload = [
+        QuizSessionAttemptItem(
+            attempt_id=a.id,
+            question_id=a.study_question_id,
+            selected_choice=a.selected_choice,
+            correct_choice=a.correct_choice,
+            outcome=a.outcome,
+            answered_at=a.answered_at,
+            reviewed_at=a.reviewed_at,
+        )
+        for a in attempt_rows
+    ]
+
+    summary = await _build_session_summary(qs, session)
+    return QuizSessionDetailResponse(
+        summary=summary,
+        questions=questions_payload,
+        attempts=attempts_payload,
+    )
+
+
+class QuizSessionPatchRequest(BaseModel):
+    """abandon → status='abandoned'. 다른 필드 패치는 현재 안 받음."""
+    action: str = Field(..., pattern="^(abandon)$")
+
+
+@router.patch("/{topic_id}/quiz-sessions/{session_id}", response_model=QuizSessionSummary)
+async def patch_quiz_session(
+    topic_id: int,
+    session_id: int,
+    body: QuizSessionPatchRequest,
+    user: Annotated[User, Depends(get_current_user)],
+    session: Annotated[AsyncSession, Depends(get_session)],
+):
+    """현재 abandon 만 지원 — 진행 중 세션 포기 (다시 시작 시 사용)."""
+    topic = await session.get(StudyTopic, topic_id)
+    _verify_topic_ownership(topic, user)
+
+    qs = await session.get(StudyQuizSession, session_id)
+    if qs is None or qs.user_id != user.id or qs.study_topic_id != topic_id:
+        raise HTTPException(status_code=404, detail="quiz_session 을 찾을 수 없습니다")
+
+    if body.action == "abandon":
+        if qs.status != "in_progress":
+            raise HTTPException(status_code=409, detail=f"이미 {qs.status} 상태입니다")
+        qs.status = "abandoned"
+        qs.updated_at = datetime.now(timezone.utc)
+        await session.commit()
+    return await _build_session_summary(qs, session)
@@ -113,5 +113,11 @@ class StudyQuestionAttempt(Base):
    answered_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), default=datetime.now, nullable=False
    )
+    # PR-10: 어떤 quiz 세션의 attempt 인지 (NULL = 세션 외 직접 입력 또는 세션 삭제됨).
+    quiz_session_id: Mapped[int | None] = mapped_column(
+        BigInteger, ForeignKey("study_quiz_sessions.id", ondelete="SET NULL"), nullable=True
+    )
+    # PR-10: 결과 카드에서 "학습완료" 체크 시 박힘. NULL = 미확인.
+    reviewed_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True))

    question: Mapped["StudyQuestion"] = relationship(back_populates="attempts")
@@ -0,0 +1,50 @@
+"""study_quiz_sessions ORM (PR-10) — 문제풀이 세션 기록 + 이어풀기.
+
+한 토픽의 한 회차 풀이 = 한 행. question_ids 는 출제 순서 스냅샷.
+status: in_progress / done / abandoned (강한 enum 미사용 — VARCHAR 권장값).
+한 토픽당 in_progress 1개 강제는 partial unique idx (마이그레이션 207).
+"""
+
+from datetime import datetime
+
+from sqlalchemy import BigInteger, Boolean, DateTime, ForeignKey, Integer, String
+from sqlalchemy.dialects.postgresql import JSONB
+from sqlalchemy.orm import Mapped, mapped_column
+
+from core.database import Base
+
+
+class StudyQuizSession(Base):
+    __tablename__ = "study_quiz_sessions"
+
+    id: Mapped[int] = mapped_column(BigInteger, primary_key=True)
+    user_id: Mapped[int] = mapped_column(
+        BigInteger, ForeignKey("users.id", ondelete="CASCADE"), nullable=False
+    )
+    study_topic_id: Mapped[int] = mapped_column(
+        BigInteger, ForeignKey("study_topics.id", ondelete="CASCADE"), nullable=False
+    )
+
+    target_per_subject: Mapped[int] = mapped_column(Integer, nullable=False, default=20)
+    subject_filter: Mapped[str | None] = mapped_column(String(120))
+    wrong_only: Mapped[bool] = mapped_column(Boolean, nullable=False, default=False)
+
+    # 출제 순서 스냅샷 — list[int] (question id). 출제 후 변경 안 됨.
+    question_ids: Mapped[list] = mapped_column(JSONB, nullable=False)
+    # {subject: count} 분포. 결과 카드 통계 표시용.
+    subject_distribution: Mapped[dict] = mapped_column(JSONB, nullable=False, default=dict)
+
+    status: Mapped[str] = mapped_column(String(20), nullable=False, default="in_progress")
+    cursor: Mapped[int] = mapped_column(Integer, nullable=False, default=0)
+
+    correct_count: Mapped[int] = mapped_column(Integer, nullable=False, default=0)
+    wrong_count: Mapped[int] = mapped_column(Integer, nullable=False, default=0)
+    unsure_count: Mapped[int] = mapped_column(Integer, nullable=False, default=0)
+
+    finished_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True))
+    created_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), default=datetime.now, nullable=False
+    )
+    updated_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), default=datetime.now, onupdate=datetime.now, nullable=False
+    )
@@ -24,6 +24,9 @@
  let detail = $state(null); // { topic, sections, stats }
  let loading = $state(true);

+  // PR-10: 문제풀이 세션 (진행 중 + 최근 완료)
+  let quizSessions = $state({ active: null, recent_done: [] });
+
  // 자료 추가 모달
  let docModalOpen = $state(false);
  let docSearch = $state('');
@@ -122,6 +125,12 @@
    loading = true;
    try {
      detail = await api(`/study-topics/${topicId}`);
+      // PR-10: 세션 목록 함께 로드. 실패해도 detail 은 유지.
+      try {
+        quizSessions = await api(`/study-topics/${topicId}/quiz-sessions?limit=10`);
+      } catch {
+        quizSessions = { active: null, recent_done: [] };
+      }
    } catch (err) {
      addToast('error', err.detail || '학습 주제 로딩 실패');
      detail = null;
@@ -130,6 +139,40 @@
    }
  }

+  /** 새 문제풀이 시작 — 기존 in_progress 있으면 confirm 후 abandon. */
+  async function startNewQuiz() {
+    const hasActive = !!quizSessions.active;
+    if (hasActive) {
+      const ok = confirm(
+        `진행 중인 문제풀이 세션이 있습니다 (${quizSessions.active.cursor}/${quizSessions.active.total} 풀음). 새로 시작하면 그 세션은 포기됩니다. 진행할까요?`,
+      );
+      if (!ok) return;
+    }
+    try {
+      const res = await api(`/study-topics/${topicId}/quiz-sessions`, {
+        method: 'POST',
+        body: JSON.stringify({
+          target_per_subject: 20,
+          abandon_existing: hasActive,
+        }),
+      });
+      goto(`/study/topics/${topicId}/review?session=${res.id}`);
+    } catch (err) {
+      addToast('error', err?.detail || '문제풀이 시작 실패');
+    }
+  }
+
+  /** 진행 중 세션 이어풀기. */
+  function resumeActiveQuiz() {
+    if (!quizSessions.active) return;
+    goto(`/study/topics/${topicId}/review?session=${quizSessions.active.id}`);
+  }
+
+  function fmtDateTime(s) {
+    if (!s) return '';
+    return new Date(s).toLocaleString('ko-KR', { dateStyle: 'short', timeStyle: 'short' });
+  }
+
  $effect(() => {
    void topicId;
    if (Number.isFinite(topicId)) {
@@ -515,7 +558,7 @@
          <Button href={`/study/topics/${topicId}/exam-rounds`} size="sm" variant="ghost" icon={ListChecks}>회차 보기</Button>
          <Button href={`/study/topics/${topicId}/questions/new`} size="sm" variant="ghost" icon={Plus}>새 문제</Button>
          {#if (detail.sections.questions?.length ?? 0) > 0}
-            <Button href={`/study/topics/${topicId}/review`} size="sm" icon={Play}>문제풀이</Button>
+            <Button onclick={startNewQuiz} size="sm" icon={Play}>새 문제풀이</Button>
          {/if}
        </div>
      </div>
@@ -524,6 +567,61 @@
          이 주제에 입력된 문제가 없습니다. "새 문제" 로 4지선다 객관식을 추가하면 문제풀이 모드에서 무작위 출제됩니다.
        </div>
      {:else}
+        <!-- PR-10: 진행 중 세션 카드 -->
+        {#if quizSessions.active}
+          {@const a = quizSessions.active}
+          {@const pct = a.total > 0 ? Math.round((a.cursor / a.total) * 100) : 0}
+          <div class="mb-2 p-3 rounded-lg border border-accent/40 bg-accent/5 flex items-center gap-3">
+            <Play size={16} class="text-accent shrink-0" />
+            <div class="flex-1 min-w-0">
+              <div class="text-sm text-text">
+                진행 중인 문제풀이 — <span class="font-medium">{a.cursor} / {a.total}</span> 풀음
+                <span class="text-dim text-[11px]">({pct}%)</span>
+              </div>
+              <div class="w-full h-1.5 bg-default/30 rounded-full overflow-hidden mt-1.5">
+                <div class="h-full bg-accent transition-all" style="width: {pct}%"></div>
+              </div>
+              <div class="text-[11px] text-dim mt-1">시작 {fmtDateTime(a.created_at)}</div>
+            </div>
+            <Button onclick={resumeActiveQuiz} size="sm" icon={ArrowRight} iconPosition="right">이어풀기</Button>
+          </div>
+        {/if}
+
+        <!-- PR-10: 최근 완료 세션 (결과 카드) -->
+        {#if quizSessions.recent_done?.length > 0}
+          <div class="mb-2 flex flex-col gap-1.5">
+            <div class="text-[11px] text-dim px-1">최근 결과</div>
+            {#each quizSessions.recent_done as s (s.id)}
+              {@const accuracy = s.total > 0 ? Math.round((s.correct_count / s.total) * 100) : 0}
+              <a
+                href={`/study/topics/${topicId}/quiz-sessions/${s.id}`}
+                class="flex items-center gap-3 p-2.5 rounded border border-default bg-surface hover:border-accent/40 hover:bg-bg/30 transition-colors"
+              >
+                <div class="flex-1 min-w-0">
+                  <div class="text-sm text-text flex items-center gap-2 flex-wrap">
+                    <span class="text-success">정답 {s.correct_count}</span>
+                    <span class="text-dim">·</span>
+                    <span class="text-error">오답 {s.wrong_count}</span>
+                    <span class="text-dim">·</span>
+                    <span class="text-warning">모르겠음 {s.unsure_count}</span>
+                    <span class="text-dim">·</span>
+                    <span class="text-text font-medium">정답률 {accuracy}%</span>
+                    {#if s.unreviewed_wrong_unsure_count > 0}
+                      <span class="ml-auto text-[10px] text-warning bg-warning/10 rounded px-1.5 py-0.5">미확인 {s.unreviewed_wrong_unsure_count}</span>
+                    {:else}
+                      <span class="ml-auto text-[10px] text-success bg-success/10 rounded px-1.5 py-0.5">✓ 모두 확인</span>
+                    {/if}
+                  </div>
+                  <div class="text-[11px] text-dim mt-0.5">
+                    총 {s.total}문제 · 완료 {fmtDateTime(s.finished_at)}
+                  </div>
+                </div>
+                <ArrowRight size={12} class="text-dim shrink-0" />
+              </a>
+            {/each}
+          </div>
+        {/if}
+
        <div class="flex flex-col gap-2">
          {#each detail.sections.questions as q (q.id)}
            <div class="flex items-center gap-3 p-3 rounded-lg border border-default bg-surface hover:bg-surface/80">
@@ -0,0 +1,489 @@
+<script>
+  /**
+   * /study/topics/[id]/quiz-sessions/[sid] — 문제풀이 결과 (PR-10 신규).
+   *
+   * 한 세션 = 한 결과 카드. 정답/틀린/모르겠음 3 탭.
+   *   - 정답: 본문/사용자 선택 확인만
+   *   - 틀린: PR-3 AI 해설 (RAG)
+   *   - 모르겠음: 분야(subject+scope) 설명 (PR-9 캐시)
+   * 카드별 [학습완료] 토글 (PATCH /study-question-attempts/{aid}/review-mark) — wrong/unsure 만.
+   * 헤더 "미확인 N건" → 0이면 "✓ 모두 확인".
+   */
+  import { onMount } from 'svelte';
+  import { page } from '$app/stores';
+  import { api } from '$lib/api';
+  import { addToast } from '$lib/stores/toast';
+  import {
+    ArrowLeft, CheckCircle2, XCircle, HelpCircle, Sparkles, BookOpen, AlertCircle, Square, CheckSquare,
+  } from 'lucide-svelte';
+  import { renderMathMarkdown, renderMathMarkdownInline } from '$lib/utils/mathMarkdown';
+  import Button from '$lib/components/ui/Button.svelte';
+  import Card from '$lib/components/ui/Card.svelte';
+  import Skeleton from '$lib/components/ui/Skeleton.svelte';
+  import ImgAuth from '$lib/components/ImgAuth.svelte';
+
+  let topicId = $derived(Number($page.params.id));
+  let sessionId = $derived(Number($page.params.sid));
+  let topicName = $state('');
+
+  let detail = $state(null); // {summary, questions, attempts}
+  let loading = $state(true);
+
+  // 탭 + per-card state
+  let activeTab = $state('wrong'); // 'correct' | 'wrong' | 'unsure'
+  let perCard = $state({}); // { [qid]: { open, kind, loading, error, data } }
+
+  async function loadTopic() {
+    try {
+      const t = await api(`/study-topics/${topicId}`);
+      topicName = t?.topic?.name ?? '';
+    } catch {}
+  }
+
+  async function load() {
+    loading = true;
+    try {
+      detail = await api(`/study-topics/${topicId}/quiz-sessions/${sessionId}`);
+      // 최초 탭: 틀린 → 모르겠음 → 정답 (학습 우선순위 순)
+      if ((detail.summary.wrong_count ?? 0) > 0) activeTab = 'wrong';
+      else if ((detail.summary.unsure_count ?? 0) > 0) activeTab = 'unsure';
+      else activeTab = 'correct';
+    } catch (err) {
+      addToast('error', err?.detail || '결과 로드 실패');
+      detail = null;
+    } finally {
+      loading = false;
+    }
+  }
+
+  onMount(async () => {
+    await loadTopic();
+    await load();
+  });
+
+  /** 같은 question 의 attempt 와 question 객체를 묶어서 카테고리별로 분류. */
+  let categorized = $derived.by(() => {
+    if (!detail) return { correct: [], wrong: [], unsure: [] };
+    const qById = Object.fromEntries((detail.questions ?? []).map((q) => [q.id, q]));
+    const acc = { correct: [], wrong: [], unsure: [] };
+    for (const a of detail.attempts ?? []) {
+      const q = qById[a.question_id];
+      if (!q) continue;
+      const item = { attempt: a, q };
+      if (a.outcome === 'correct') acc.correct.push(item);
+      else if (a.outcome === 'wrong') acc.wrong.push(item);
+      else if (a.outcome === 'unsure') acc.unsure.push(item);
+    }
+    return acc;
+  });
+
+  let summary = $derived(detail?.summary);
+  let unreviewedCount = $derived(summary?.unreviewed_wrong_unsure_count ?? 0);
+
+  function setCard(qid, patch) {
+    perCard = { ...perCard, [qid]: { ...(perCard[qid] ?? {}), ...patch } };
+  }
+  function toggleCardOpen(qid) {
+    const cur = perCard[qid];
+    setCard(qid, { open: !(cur?.open) });
+  }
+
+  async function loadAiExplanation(qid, regenerate = false) {
+    setCard(qid, { kind: 'ai-expl', loading: true, error: null });
+    try {
+      const res = await api(`/study-questions/${qid}/ai-explanation`, {
+        method: 'POST',
+        body: JSON.stringify({ regenerate }),
+      });
+      setCard(qid, { data: res, error: res.ai_explanation_status === 'failed' ? '풀이 생성 실패. 다시 시도하세요.' : null });
+    } catch (err) {
+      const msg = err?.status === 409
+        ? '다른 호출이 풀이를 생성 중입니다. 잠시 후 다시 시도해주세요.'
+        : (err?.detail || 'AI 풀이 생성 실패');
+      setCard(qid, { error: msg });
+    } finally {
+      setCard(qid, { loading: false });
+    }
+  }
+
+  async function loadSubjectNote(qid, regenerate = false) {
+    const item = [...categorized.correct, ...categorized.wrong, ...categorized.unsure].find((it) => it.q.id === qid);
+    if (!item) return;
+    const subject = item.q.subject || '';
+    const scope = item.q.scope || '';
+    if (!subject) {
+      setCard(qid, { kind: 'subject-note', error: '문제에 과목(subject)이 지정되지 않아 분야 설명을 만들 수 없습니다.' });
+      return;
+    }
+    setCard(qid, { kind: 'subject-note', loading: true, error: null });
+    try {
+      const res = await api(`/study-topics/${topicId}/subject-notes/generate`, {
+        method: 'POST',
+        body: JSON.stringify({ subject, scope, regenerate }),
+      });
+      setCard(qid, { data: res, error: res.status === 'failed' ? '분야 설명 생성 실패. 다시 시도하세요.' : null });
+    } catch (err) {
+      const msg = err?.status === 409
+        ? '다른 호출이 분야 설명을 생성 중입니다. 잠시 후 다시 시도해주세요.'
+        : (err?.detail || '분야 설명 생성 실패');
+      setCard(qid, { error: msg });
+    } finally {
+      setCard(qid, { loading: false });
+    }
+  }
+
+  /** 학습완료 토글. PATCH 후 detail.attempts + summary.unreviewed_count 갱신. */
+  async function toggleReviewed(attempt) {
+    const next = !attempt.reviewed_at;
+    try {
+      const res = await api(`/study-question-attempts/${attempt.attempt_id}/review-mark`, {
+        method: 'PATCH',
+        body: JSON.stringify({ reviewed: next }),
+      });
+      // 로컬 상태 갱신 (서버 round-trip 없이)
+      attempt.reviewed_at = res.reviewed_at;
+      // unreviewed_count 재계산
+      if (detail && detail.summary) {
+        const remaining = (detail.attempts ?? []).filter(
+          (a) => (a.outcome === 'wrong' || a.outcome === 'unsure') && !a.reviewed_at
+        ).length;
+        detail.summary = { ...detail.summary, unreviewed_wrong_unsure_count: remaining };
+      }
+      // perCard 객체 reactivity 트리거 (attempt mutate 만으로는 안 잡힘)
+      perCard = { ...perCard };
+    } catch (err) {
+      addToast('error', err?.detail || '체크 실패');
+    }
+  }
+
+  function shortText(s, n = 80) {
+    if (!s) return '';
+    const t = s.replace(/\s+/g, ' ').trim();
+    return t.length > n ? t.slice(0, n) + '…' : t;
+  }
+  function fmtDateTime(s) {
+    if (!s) return '';
+    return new Date(s).toLocaleString('ko-KR', { dateStyle: 'short', timeStyle: 'short' });
+  }
+</script>
+
+<svelte:head><title>결과 — {topicName || '주제'}</title></svelte:head>
+
+<div class="p-4 md:p-6 max-w-3xl mx-auto">
+  <div class="flex items-center gap-2 text-xs md:text-sm mb-3">
+    <a href="/study" class="text-dim hover:text-text">공부</a>
+    <span class="text-faint">/</span>
+    <a href="/study/topics" class="text-dim hover:text-text">주제</a>
+    <span class="text-faint">/</span>
+    <a href={`/study/topics/${topicId}`} class="text-dim hover:text-text truncate">{topicName || '...'}</a>
+    <span class="text-faint">/</span>
+    <span class="text-text font-medium">결과 #{sessionId}</span>
+  </div>
+
+  {#if loading}
+    <Skeleton h="h-32" rounded="lg" />
+  {:else if !detail}
+    <Card>
+      {#snippet children()}
+        <div class="p-6 text-center text-dim">결과를 불러올 수 없습니다.</div>
+      {/snippet}
+    </Card>
+  {:else}
+    {@const s = summary}
+    {@const accuracy = s.total > 0 ? Math.round((s.correct_count / s.total) * 100) : 0}
+    <Card>
+      {#snippet children()}
+        <div class="p-5 flex flex-col gap-4">
+          <div class="flex items-center justify-between flex-wrap gap-2">
+            <h1 class="text-base font-semibold text-text">결과</h1>
+            <div class="text-xs text-dim flex items-center gap-2">
+              {#if unreviewedCount > 0}
+                <span class="text-warning bg-warning/10 rounded px-2 py-0.5">미확인 {unreviewedCount}건</span>
+              {:else}
+                <span class="text-success bg-success/10 rounded px-2 py-0.5">✓ 모두 확인</span>
+              {/if}
+              <span>완료 {fmtDateTime(s.finished_at)}</span>
+            </div>
+          </div>
+          <div class="text-sm text-dim">
+            총 {s.total}문제 ·
+            <span class="text-success">정답 {s.correct_count}</span> ·
+            <span class="text-error">오답 {s.wrong_count}</span> ·
+            <span class="text-warning">모르겠음 {s.unsure_count}</span> ·
+            <span class="text-text font-medium">정답률 {accuracy}%</span>
+          </div>
+
+          {#if Object.keys(s.subject_distribution || {}).length > 0}
+            <div class="text-[11px] text-dim">
+              과목 분포:
+              {#each Object.entries(s.subject_distribution) as [sub, n], i}
+                <span>{i > 0 ? ' · ' : ''}{sub || '미분류'} {n}</span>
+              {/each}
+            </div>
+          {/if}
+
+          <!-- 탭 -->
+          <div class="flex border-b border-default">
+            <button
+              type="button"
+              onclick={() => (activeTab = 'wrong')}
+              class="px-4 py-2 text-sm border-b-2 transition-colors flex items-center gap-2
+                {activeTab === 'wrong' ? 'border-error text-error font-medium' : 'border-transparent text-dim hover:text-text'}"
+            >
+              <XCircle size={14} />
+              <span>틀린</span>
+              <span class="text-[10px] bg-error/10 text-error rounded px-1.5 py-0.5">{s.wrong_count}</span>
+            </button>
+            <button
+              type="button"
+              onclick={() => (activeTab = 'unsure')}
+              class="px-4 py-2 text-sm border-b-2 transition-colors flex items-center gap-2
+                {activeTab === 'unsure' ? 'border-warning text-warning font-medium' : 'border-transparent text-dim hover:text-text'}"
+            >
+              <HelpCircle size={14} />
+              <span>모르겠음</span>
+              <span class="text-[10px] bg-warning/10 text-warning rounded px-1.5 py-0.5">{s.unsure_count}</span>
+            </button>
+            <button
+              type="button"
+              onclick={() => (activeTab = 'correct')}
+              class="px-4 py-2 text-sm border-b-2 transition-colors flex items-center gap-2
+                {activeTab === 'correct' ? 'border-success text-success font-medium' : 'border-transparent text-dim hover:text-text'}"
+            >
+              <CheckCircle2 size={14} />
+              <span>정답</span>
+              <span class="text-[10px] bg-success/10 text-success rounded px-1.5 py-0.5">{s.correct_count}</span>
+            </button>
+          </div>
+
+          {#if activeTab === 'correct'}
+            {@render resultList(categorized.correct, 'correct')}
+          {:else if activeTab === 'wrong'}
+            {@render resultList(categorized.wrong, 'wrong')}
+          {:else if activeTab === 'unsure'}
+            {@render resultList(categorized.unsure, 'unsure')}
+          {/if}
+
+          <div class="flex gap-2 justify-end pt-3 border-t border-default">
+            <Button href={`/study/topics/${topicId}`} variant="ghost" icon={ArrowLeft}>주제로</Button>
+          </div>
+        </div>
+      {/snippet}
+    </Card>
+  {/if}
+</div>
+
+{#snippet resultList(items, kind)}
+  {#if items.length === 0}
+    <div class="text-xs text-dim p-4 text-center border border-dashed border-default rounded">
+      {#if kind === 'correct'}정답 처리된 문제가 없습니다.
+      {:else if kind === 'wrong'}오답 처리된 문제가 없습니다.
+      {:else}모르겠음 처리된 문제가 없습니다.
+      {/if}
+    </div>
+  {:else}
+    <ul class="flex flex-col gap-2">
+      {#each items as it (it.q.id)}
+        {@const cardState = perCard[it.q.id] ?? {}}
+        {@const isOpen = cardState.open === true}
+        {@const reviewed = !!it.attempt.reviewed_at}
+        <li class="rounded border bg-surface overflow-hidden
+          {kind !== 'correct' && reviewed ? 'border-success/30 bg-success/5' : 'border-default'}">
+          <button
+            type="button"
+            onclick={() => toggleCardOpen(it.q.id)}
+            class="w-full text-left p-3 flex items-start gap-3 hover:bg-bg/30 transition-colors"
+          >
+            <div class="flex-1 min-w-0">
+              <div class="text-sm text-text">{shortText(it.q.question_text, 100)}</div>
+              <div class="text-[11px] text-dim mt-1 flex items-center gap-2 flex-wrap">
+                {#if it.q.subject}<span>{it.q.subject}</span>{/if}
+                {#if it.q.scope}<span>· {it.q.scope}</span>{/if}
+                {#if it.q.exam_round}<span>· {it.q.exam_round}</span>{/if}
+                <span class="ml-auto">
+                  {#if kind === 'correct'}
+                    <span class="text-success">선택 {it.attempt.selected_choice}번 = 정답</span>
+                  {:else if kind === 'wrong'}
+                    <span class="text-error">선택 {it.attempt.selected_choice ?? '?'}번</span>
+                    <span class="text-dim"> · 정답 {it.attempt.correct_choice}번</span>
+                  {:else}
+                    <span class="text-warning">모르겠음</span>
+                    <span class="text-dim"> · 정답 {it.attempt.correct_choice}번</span>
+                  {/if}
+                  {#if kind !== 'correct' && reviewed}
+                    <CheckCircle2 size={12} class="inline ml-1 text-success" />
+                  {/if}
+                </span>
+              </div>
+            </div>
+          </button>
+
+          {#if isOpen}
+            <div class="border-t border-default p-3 flex flex-col gap-3 bg-bg/20">
+              <div class="text-sm text-text leading-relaxed math-area">{@html renderMathMarkdown(it.q.question_text)}</div>
+
+              {#if it.q.images?.length > 0}
+                <div class="grid grid-cols-1 sm:grid-cols-2 gap-2">
+                  {#each it.q.images as img (img.id)}
+                    <ImgAuth src={img.served_url} class="w-full max-h-60 object-contain rounded border border-default bg-bg/30" />
+                  {/each}
+                </div>
+              {/if}
+
+              <div class="flex flex-col gap-1.5">
+                {#each it.q.choices as ch (ch.number)}
+                  {@const isCorrect = it.attempt.correct_choice === ch.number}
+                  {@const isSelected = it.attempt.selected_choice === ch.number}
+                  <div class="p-2.5 rounded border flex items-start gap-3 text-sm
+                    {isCorrect ? 'border-success bg-success/10 text-text'
+                     : (isSelected && !isCorrect) ? 'border-error bg-error/10 text-text'
+                     : 'border-default bg-surface text-dim'}"
+                  >
+                    <span class="font-semibold w-5 shrink-0">{ch.number}</span>
+                    <span class="flex-1 math-area overflow-x-auto">{@html renderMathMarkdownInline(ch.text)}</span>
+                    {#if isCorrect}<CheckCircle2 size={14} class="text-success shrink-0" />
+                    {:else if isSelected && !isCorrect}<XCircle size={14} class="text-error shrink-0" />
+                    {/if}
+                  </div>
+                {/each}
+              </div>
+
+              {#if it.q.explanation}
+                <div class="rounded border border-default bg-surface p-3 text-xs text-text math-area">
+                  <div class="text-[10px] text-dim mb-1">사용자 입력 해설</div>
+                  <div class="text-text">{@html renderMathMarkdown(it.q.explanation)}</div>
+                </div>
+              {/if}
+
+              {#if kind === 'wrong'}
+                {@render aiExplanationBlock(it.q.id, cardState)}
+              {:else if kind === 'unsure'}
+                {@render subjectNoteBlock(it, cardState)}
+              {/if}
+
+              {#if kind !== 'correct'}
+                <div class="flex justify-end pt-2 border-t border-default">
+                  <button
+                    type="button"
+                    onclick={() => toggleReviewed(it.attempt)}
+                    class="flex items-center gap-2 text-xs px-3 py-1.5 rounded border transition-colors
+                      {reviewed
+                        ? 'border-success bg-success/10 text-success hover:bg-success/15'
+                        : 'border-default text-dim hover:text-text hover:border-warning/40'}"
+                  >
+                    {#if reviewed}<CheckSquare size={14} />{:else}<Square size={14} />{/if}
+                    <span>{reviewed ? '학습완료' : '학습완료로 표시'}</span>
+                  </button>
+                </div>
+              {/if}
+            </div>
+          {/if}
+        </li>
+      {/each}
+    </ul>
+  {/if}
+{/snippet}
+
+{#snippet aiExplanationBlock(qid, st)}
+  {@const data = st.data}
+  {@const isLoaded = !!data?.ai_explanation}
+  <div class="rounded border border-default bg-bg/30 p-3 flex flex-col gap-2">
+    <div class="flex items-center gap-2 flex-wrap">
+      <Sparkles size={14} class="text-accent" />
+      <span class="text-xs font-semibold text-text">AI 풀이</span>
+      {#if data?.is_stale}
+        <span class="text-[10px] text-warning border border-warning/40 rounded px-1.5 py-0.5">stale</span>
+      {/if}
+      {#if data?.from_cache && !data?.is_stale}
+        <span class="text-[10px] text-dim">캐시</span>
+      {/if}
+      <span class="ml-auto flex items-center gap-1.5">
+        {#if !isLoaded}
+          <Button size="sm" variant="ghost" onclick={() => loadAiExplanation(qid, false)} loading={st.loading}>AI 해설 보기</Button>
+        {:else if data?.is_stale}
+          <Button size="sm" onclick={() => loadAiExplanation(qid, true)} loading={st.loading}>다시 생성</Button>
+        {:else if data?.ai_explanation_status === 'failed'}
+          <Button size="sm" onclick={() => loadAiExplanation(qid, true)} loading={st.loading}>다시 시도</Button>
+        {:else}
+          <Button size="sm" variant="ghost" onclick={() => loadAiExplanation(qid, true)} loading={st.loading}>다시 생성</Button>
+        {/if}
+      </span>
+    </div>
+
+    {#if data?.is_stale}
+      <div class="text-[11px] text-warning bg-warning/5 border border-warning/30 rounded px-2 py-1.5 flex items-start gap-1.5">
+        <AlertCircle size={12} class="mt-0.5 shrink-0" />
+        <span>이 풀이는 정답·문제가 수정된 후의 이전 풀이입니다. "다시 생성" 으로 새로 만들 수 있습니다.</span>
+      </div>
+    {/if}
+    {#if st.error}
+      <div class="text-[11px] text-error">{st.error}</div>
+    {/if}
+    {#if isLoaded}
+      <div class="text-xs text-text leading-relaxed prose prose-sm prose-invert max-w-none math-area">
+        {@html renderMathMarkdown(data.ai_explanation)}
+      </div>
+      {#if data.evidence?.length}
+        <details class="text-[10px] text-dim">
+          <summary class="cursor-pointer hover:text-text">참고 근거 {data.evidence.length}건</summary>
+          <ul class="mt-1 flex flex-col gap-1">
+            {#each data.evidence as ev}
+              <li>
+                <span class="text-text">{ev.source_type === 'document' ? '📄' : '❓'} {ev.title}</span>
+                <div class="pl-4 truncate">{ev.snippet}</div>
+              </li>
+            {/each}
+          </ul>
+        </details>
+      {/if}
+    {/if}
+  </div>
+{/snippet}
+
+{#snippet subjectNoteBlock(it, st)}
+  {@const data = st.data}
+  {@const isLoaded = !!data?.content}
+  <div class="rounded border border-default bg-bg/30 p-3 flex flex-col gap-2">
+    <div class="flex items-center gap-2 flex-wrap">
+      <BookOpen size={14} class="text-warning" />
+      <span class="text-xs font-semibold text-text">분야 설명</span>
+      <span class="text-[10px] text-dim">
+        {it.q.subject || '(과목 미지정)'}{it.q.scope ? ` · ${it.q.scope}` : ''}
+      </span>
+      {#if data?.from_cache && data?.status === 'ready'}
+        <span class="text-[10px] text-dim">캐시</span>
+      {/if}
+      <span class="ml-auto flex items-center gap-1.5">
+        {#if !isLoaded}
+          <Button size="sm" variant="ghost" onclick={() => loadSubjectNote(it.q.id, false)} loading={st.loading}>분야 설명 보기</Button>
+        {:else if data?.status === 'failed'}
+          <Button size="sm" onclick={() => loadSubjectNote(it.q.id, true)} loading={st.loading}>다시 시도</Button>
+        {:else}
+          <Button size="sm" variant="ghost" onclick={() => loadSubjectNote(it.q.id, true)} loading={st.loading}>다시 생성</Button>
+        {/if}
+      </span>
+    </div>
+
+    {#if st.error}
+      <div class="text-[11px] text-error">{st.error}</div>
+    {/if}
+    {#if isLoaded}
+      <div class="text-xs text-text leading-relaxed prose prose-sm prose-invert max-w-none math-area">
+        {@html renderMathMarkdown(data.content)}
+      </div>
+      {#if data.evidence?.length}
+        <details class="text-[10px] text-dim">
+          <summary class="cursor-pointer hover:text-text">참고 근거 {data.evidence.length}건</summary>
+          <ul class="mt-1 flex flex-col gap-1">
+            {#each data.evidence as ev}
+              <li>
+                <span class="text-text">{ev.source_type === 'document' ? '📄' : '❓'} {ev.title}</span>
+                <div class="pl-4 truncate">{ev.snippet}</div>
+              </li>
+            {/each}
+          </ul>
+        </details>
+      {/if}
+    {/if}
+  </div>
+{/snippet}
@@ -1,19 +1,21 @@
 <script>
  /**
-   * /study/topics/[id]/review — 문제풀이 (PR-9 개편).
+   * /study/topics/[id]/review — 문제풀이 (PR-9 + PR-10).
   *
-   * 풀이 중 정답·해설 노출 안 함 — 시험처럼 다 풀고 결과 화면에서 한 번에.
-   * "모르겠음" 5번째 옵션 추가. 답 클릭 시 즉시 다음 문제로 자동 진행.
-   * 결과 화면 = 정답·틀린·모르겠음 3 카테고리. 카드 클릭 시:
-   *   - 정답: 본문/정답/사용자 선택 확인만
-   *   - 틀린: PR-3 AI 해설
-   *   - 모르겠음: 분야(subject+scope) 설명 (PR-9 신규)
+   * 라우트 진입 모드:
+   *   - ?session=N 있으면 해당 세션 로드 (이어풀기) — 'playing'.
+   *   - 없으면 'start' UI (옵션 입력 + 시작).
+   *
+   * 풀이 중 정답·해설 노출 안 함. "모르겠음" 5번째 옵션. 답 클릭 시 즉시 다음.
+   * 마지막 문제 풀이 후 (서버 status='done') /quiz-sessions/[sid] 결과 페이지로 redirect.
+   * 그 결과 페이지에 정답/오답/모르겠음 3 카테고리 + AI 해설 + 분야 설명 + 학습완료 체크.
   */
  import { onMount } from 'svelte';
  import { page } from '$app/stores';
+  import { goto } from '$app/navigation';
  import { api } from '$lib/api';
  import { addToast } from '$lib/stores/toast';
-  import { ArrowLeft, Play, CheckCircle2, XCircle, HelpCircle, RotateCcw, Sparkles, BookOpen, AlertCircle } from 'lucide-svelte';
+  import { ArrowLeft, Play, HelpCircle } from 'lucide-svelte';
  import { renderMathMarkdown, renderMathMarkdownInline } from '$lib/utils/mathMarkdown';
  import Button from '$lib/components/ui/Button.svelte';
  import Card from '$lib/components/ui/Card.svelte';
@@ -24,34 +26,22 @@
  let topicId = $derived(Number($page.params.id));
  let topicName = $state('');

-  // 진입 화면 옵션
-  let mode = $state('start'); // 'start' | 'playing' | 'done'
+  // 진입 화면 옵션 (start 모드용)
+  let mode = $state('start'); // 'start' | 'playing'
  let optSubject = $state('');
  let optWrongOnly = $state(false);
  let optTarget = $state(20);

-  // 출제 결과
-  let questions = $state([]);
-  let total = $state(0);
-  let distribution = $state({});
-
-  // 진행 상태
-  let cursor = $state(0); // 0-based
+  // 세션 + 문제 로드
+  let sessionId = $state(null);
+  let questions = $state([]); // 출제 순서대로 (서버에서 받음)
+  let cursor = $state(0); // 0-based — 다음 풀 문제 index
  let submitting = $state(false);
-
-  // 세션 누적 — 각 문제마다 {qid, q, attempt} 저장
-  // attempt = AttemptResponse: {is_correct, selected_choice, correct_choice, outcome, explanation, stats}
-  let results = $state([]);
-
  let loading = $state(true);

-  // 결과 화면 — 활성 탭
-  let activeTab = $state('wrong'); // 'correct' | 'wrong' | 'unsure'
-
-  // 결과 카드별 expand 상태 + AI 호출 캐시
-  // perCard[qid] = { open, kind: 'ai-expl'|'subject-note'|'view',
-  //                   loading, error, data: {...response...} }
-  let perCard = $state({});
+  let progressTotal = $derived(questions.length);
+  let currentQ = $derived(questions[cursor] ?? null);
+  let progressLabel = $derived(progressTotal > 0 ? `${cursor + 1} / ${progressTotal}` : '0 / 0');

  async function loadTopic() {
    try {
@@ -60,158 +50,103 @@
    } catch {}
  }

-  onMount(async () => {
-    loading = true;
-    await loadTopic();
-    loading = false;
-  });
-
-  async function start() {
+  /** ?session=N 로드. 풀이된 attempt 갯수 = cursor 위치 (서버 신뢰). */
+  async function loadSession(sid) {
    loading = true;
    try {
-      const params = new URLSearchParams();
-      params.set('target_per_subject', String(optTarget));
-      if (optSubject.trim()) params.set('subject', optSubject.trim());
-      if (optWrongOnly) params.set('wrong_only', 'true');
-      const res = await api(`/study-topics/${topicId}/review/questions?${params}`);
-      questions = res.items;
-      total = res.total;
-      distribution = res.subject_distribution || {};
-      cursor = 0;
-      results = [];
-      perCard = {};
-      if (questions.length === 0) {
-        addToast('info', '출제할 문제가 없습니다.');
-      } else {
-        mode = 'playing';
+      const detail = await api(`/study-topics/${topicId}/quiz-sessions/${sid}`);
+      const summary = detail.summary;
+      if (summary.status === 'done') {
+        // 이미 끝난 세션 — 결과 페이지로.
+        goto(`/study/topics/${topicId}/quiz-sessions/${sid}`, { replaceState: true });
+        return;
      }
+      if (summary.status === 'abandoned') {
+        addToast('info', '이 세션은 이미 포기 처리되어 새 세션을 시작합니다');
+        goto(`/study/topics/${topicId}`, { replaceState: true });
+        return;
+      }
+      sessionId = summary.id;
+      questions = detail.questions ?? [];
+      cursor = summary.cursor;
+      mode = 'playing';
    } catch (err) {
-      addToast('error', err.detail || '문제풀이 시작 실패');
+      addToast('error', err?.detail || '세션 로드 실패');
+      goto(`/study/topics/${topicId}`, { replaceState: true });
    } finally {
      loading = false;
    }
  }

-  /** answer = 1|2|3|4 (객관식) 또는 'unsure' (모르겠음). 즉시 제출 + 자동 진행. */
+  onMount(async () => {
+    await loadTopic();
+    const url = new URL(window.location.href);
+    const sid = url.searchParams.get('session');
+    if (sid) {
+      await loadSession(Number(sid));
+    } else {
+      loading = false;
+    }
+  });
+
+  /** 'start' 모드에서 [시작] 클릭 → 신규 세션 생성 후 ?session=N 으로 이동. */
+  async function start() {
+    loading = true;
+    try {
+      const res = await api(`/study-topics/${topicId}/quiz-sessions`, {
+        method: 'POST',
+        body: JSON.stringify({
+          target_per_subject: optTarget,
+          subject: optSubject.trim() || null,
+          wrong_only: optWrongOnly,
+          abandon_existing: false, // start 화면에서는 in_progress 있으면 그쪽으로 이어감.
+        }),
+      });
+      goto(`/study/topics/${topicId}/review?session=${res.id}`, { replaceState: true });
+      // loadSession 은 navigate 후 onMount 가 다시 안 트리거되므로 직접 호출.
+      await loadSession(res.id);
+    } catch (err) {
+      addToast('error', err?.detail || '문제풀이 시작 실패');
+      loading = false;
+    }
+  }
+
+  /** answer = 1|2|3|4 (객관식) 또는 'unsure'. 즉시 제출 + cursor 갱신.
+   *  서버가 status='done' 으로 응답하면 결과 페이지로 이동. */
  async function submitAndAdvance(answer) {
-    if (submitting) return;
+    if (submitting || !currentQ) return;
    submitting = true;
    try {
-      const q = questions[cursor];
      const body = answer === 'unsure'
-        ? { is_unsure: true }
-        : { selected_choice: Number(answer) };
-      const res = await api(`/study-questions/${q.id}/attempt`, {
+        ? { is_unsure: true, quiz_session_id: sessionId }
+        : { selected_choice: Number(answer), quiz_session_id: sessionId };
+      const res = await api(`/study-questions/${currentQ.id}/attempt`, {
        method: 'POST',
        body: JSON.stringify(body),
      });
-      results = [...results, { qid: q.id, q, attempt: res }];
-      if (cursor + 1 >= questions.length) {
-        // 최초 탭은 틀린 (= 학습 우선순위 높음). 없으면 모르겠음 → 정답.
-        const wrongCount = results.filter((r) => r.attempt.outcome === 'wrong').length;
-        const unsureCount = results.filter((r) => r.attempt.outcome === 'unsure').length;
-        if (wrongCount > 0) activeTab = 'wrong';
-        else if (unsureCount > 0) activeTab = 'unsure';
-        else activeTab = 'correct';
-        mode = 'done';
-      } else {
-        cursor += 1;
+      // 서버 cursor 신뢰.
+      if (res.quiz_session_status === 'done') {
+        goto(`/study/topics/${topicId}/quiz-sessions/${sessionId}`, { replaceState: true });
+        return;
      }
+      cursor = typeof res.quiz_session_cursor === 'number' ? res.quiz_session_cursor : cursor + 1;
    } catch (err) {
-      addToast('error', err.detail || '제출 실패');
+      addToast('error', err?.detail || '제출 실패');
    } finally {
      submitting = false;
    }
  }

-  function restart() {
-    mode = 'start';
-    questions = [];
-    results = [];
-    perCard = {};
-    cursor = 0;
-  }
-
-  let currentQ = $derived(questions[cursor] ?? null);
-  let progress = $derived(questions.length > 0 ? `${cursor + 1} / ${questions.length}` : '0 / 0');
-
-  // 결과 화면용 — 카테고리별 분류
-  let resultsByOutcome = $derived.by(() => {
-    const correct = [];
-    const wrong = [];
-    const unsure = [];
-    for (const r of results) {
-      if (r.attempt.outcome === 'correct') correct.push(r);
-      else if (r.attempt.outcome === 'wrong') wrong.push(r);
-      else if (r.attempt.outcome === 'unsure') unsure.push(r);
-    }
-    return { correct, wrong, unsure };
-  });
-
-  let answeredCount = $derived(results.length);
-  let correctCount = $derived(resultsByOutcome.correct.length);
-  let wrongCount = $derived(resultsByOutcome.wrong.length);
-  let unsureCount = $derived(resultsByOutcome.unsure.length);
-
-  function setCard(qid, patch) {
-    perCard = { ...perCard, [qid]: { ...(perCard[qid] ?? {}), ...patch } };
-  }
-
-  function toggleCardOpen(qid) {
-    const cur = perCard[qid];
-    setCard(qid, { open: !(cur?.open) });
-  }
-
-  /** 틀린 카드: PR-3 AI 해설 호출. */
-  async function loadAiExplanation(qid, regenerate = false) {
-    setCard(qid, { kind: 'ai-expl', loading: true, error: null });
+  async function abandonSession() {
+    if (!sessionId) return;
+    if (!confirm('현재 진행 중인 풀이를 포기하고 주제 화면으로 돌아갑니다. 진행률은 보존됩니다.')) return;
    try {
-      const res = await api(`/study-questions/${qid}/ai-explanation`, {
-        method: 'POST',
-        body: JSON.stringify({ regenerate }),
+      await api(`/study-topics/${topicId}/quiz-sessions/${sessionId}`, {
+        method: 'PATCH',
+        body: JSON.stringify({ action: 'abandon' }),
      });
-      setCard(qid, { data: res, error: res.ai_explanation_status === 'failed' ? '풀이 생성 실패. 다시 시도하세요.' : null });
-    } catch (err) {
-      const msg = err?.status === 409
-        ? '다른 호출이 풀이를 생성 중입니다. 잠시 후 다시 시도해주세요.'
-        : (err?.detail || 'AI 풀이 생성 실패');
-      setCard(qid, { error: msg });
-    } finally {
-      setCard(qid, { loading: false });
-    }
-  }
-
-  /** 모르겠음 카드: 분야 설명 호출. (subject + scope 단위 캐시) */
-  async function loadSubjectNote(qid, regenerate = false) {
-    const r = results.find((x) => x.qid === qid);
-    if (!r) return;
-    const subject = r.q.subject || '';
-    const scope = r.q.scope || '';
-    if (!subject) {
-      setCard(qid, { kind: 'subject-note', error: '문제에 과목(subject)이 지정되지 않아 분야 설명을 만들 수 없습니다.' });
-      return;
-    }
-    setCard(qid, { kind: 'subject-note', loading: true, error: null });
-    try {
-      const res = await api(`/study-topics/${topicId}/subject-notes/generate`, {
-        method: 'POST',
-        body: JSON.stringify({ subject, scope, regenerate }),
-      });
-      setCard(qid, { data: res, error: res.status === 'failed' ? '분야 설명 생성 실패. 다시 시도하세요.' : null });
-    } catch (err) {
-      const msg = err?.status === 409
-        ? '다른 호출이 분야 설명을 생성 중입니다. 잠시 후 다시 시도해주세요.'
-        : (err?.detail || '분야 설명 생성 실패');
-      setCard(qid, { error: msg });
-    } finally {
-      setCard(qid, { loading: false });
-    }
-  }
-
-  function shortText(s, n = 80) {
-    if (!s) return '';
-    const t = s.replace(/\s+/g, ' ').trim();
-    return t.length > n ? t.slice(0, n) + '…' : t;
+    } catch {}
+    goto(`/study/topics/${topicId}`);
  }
 </script>

@@ -238,6 +173,7 @@
          <p class="text-xs text-dim">
            기본은 과목별 {optTarget}문제씩 무작위 균등 추출. 한 과목이 부족하면 가용한 만큼만 출제됩니다.
            풀이 중 정답·해설은 표시하지 않으며, 다 풀면 결과 화면에서 카테고리별로 한 번에 확인합니다.
+            나갔다 와도 같은 위치에서 이어풀 수 있습니다.
          </p>

          <div class="grid grid-cols-1 md:grid-cols-2 gap-3">
@@ -272,12 +208,17 @@
    </Card>
  {:else if mode === 'playing' && currentQ}
    <div class="mb-3 flex items-center justify-between text-xs text-dim flex-wrap gap-2">
-      <span>{progress}</span>
+      <span>{progressLabel}</span>
      <span>
        {#if currentQ.subject}<span>{currentQ.subject}</span>{/if}
        {#if currentQ.scope}<span> · {currentQ.scope}</span>{/if}
      </span>
-      <span>풀이 {answeredCount} / {questions.length}</span>
+      <button type="button" onclick={abandonSession} class="text-dim hover:text-warning text-[11px]">중단</button>
+    </div>
+
+    <!-- 진행 바 -->
+    <div class="w-full h-1.5 bg-default/30 rounded-full overflow-hidden mb-3">
+      <div class="h-full bg-accent transition-all" style="width: {progressTotal > 0 ? (cursor / progressTotal) * 100 : 0}%"></div>
    </div>

    <Card>
@@ -323,282 +264,5 @@
        </div>
      {/snippet}
    </Card>
-  {:else if mode === 'done'}
-    <!-- 결과 화면 -->
-    <Card>
-      {#snippet children()}
-        <div class="p-5 flex flex-col gap-4">
-          <div class="flex items-center justify-between flex-wrap gap-2">
-            <h1 class="text-base font-semibold text-text">결과</h1>
-            <div class="text-xs text-dim">
-              총 {answeredCount}문제 ·
-              <span class="text-success">정답 {correctCount}</span> ·
-              <span class="text-error">오답 {wrongCount}</span> ·
-              <span class="text-warning">모르겠음 {unsureCount}</span>
-              {#if answeredCount > 0}
-                · 정답률 {Math.round((correctCount / answeredCount) * 100)}%
  {/if}
 </div>
-          </div>
-
-          {#if Object.keys(distribution).length > 0}
-            <div class="text-[11px] text-dim">
-              과목 분포:
-              {#each Object.entries(distribution) as [s, n], i}
-                <span>{i > 0 ? ' · ' : ''}{s || '미분류'} {n}</span>
-              {/each}
-            </div>
-          {/if}
-
-          <!-- 탭 -->
-          <div class="flex border-b border-default">
-            <button
-              type="button"
-              onclick={() => (activeTab = 'wrong')}
-              class="px-4 py-2 text-sm border-b-2 transition-colors flex items-center gap-2
-                {activeTab === 'wrong' ? 'border-error text-error font-medium' : 'border-transparent text-dim hover:text-text'}"
-            >
-              <XCircle size={14} />
-              <span>틀린</span>
-              <span class="text-[10px] bg-error/10 text-error rounded px-1.5 py-0.5">{wrongCount}</span>
-            </button>
-            <button
-              type="button"
-              onclick={() => (activeTab = 'unsure')}
-              class="px-4 py-2 text-sm border-b-2 transition-colors flex items-center gap-2
-                {activeTab === 'unsure' ? 'border-warning text-warning font-medium' : 'border-transparent text-dim hover:text-text'}"
-            >
-              <HelpCircle size={14} />
-              <span>모르겠음</span>
-              <span class="text-[10px] bg-warning/10 text-warning rounded px-1.5 py-0.5">{unsureCount}</span>
-            </button>
-            <button
-              type="button"
-              onclick={() => (activeTab = 'correct')}
-              class="px-4 py-2 text-sm border-b-2 transition-colors flex items-center gap-2
-                {activeTab === 'correct' ? 'border-success text-success font-medium' : 'border-transparent text-dim hover:text-text'}"
-            >
-              <CheckCircle2 size={14} />
-              <span>정답</span>
-              <span class="text-[10px] bg-success/10 text-success rounded px-1.5 py-0.5">{correctCount}</span>
-            </button>
-          </div>
-
-          <!-- 카드 리스트 -->
-          {#if activeTab === 'correct'}
-            {@render resultList(resultsByOutcome.correct, 'correct')}
-          {:else if activeTab === 'wrong'}
-            {@render resultList(resultsByOutcome.wrong, 'wrong')}
-          {:else if activeTab === 'unsure'}
-            {@render resultList(resultsByOutcome.unsure, 'unsure')}
-          {/if}
-
-          <div class="flex gap-2 justify-end pt-3 border-t border-default">
-            <Button href={`/study/topics/${topicId}`} variant="ghost" icon={ArrowLeft}>주제로</Button>
-            <Button onclick={restart} icon={RotateCcw}>다시 풀기</Button>
-          </div>
-        </div>
-      {/snippet}
-    </Card>
-  {/if}
-</div>
-
-{#snippet resultList(items, kind)}
-  {#if items.length === 0}
-    <div class="text-xs text-dim p-4 text-center border border-dashed border-default rounded">
-      {#if kind === 'correct'}정답 처리된 문제가 없습니다.
-      {:else if kind === 'wrong'}오답 처리된 문제가 없습니다.
-      {:else}모르겠음 처리된 문제가 없습니다.
-      {/if}
-    </div>
-  {:else}
-    <ul class="flex flex-col gap-2">
-      {#each items as r (r.qid)}
-        {@const cardState = perCard[r.qid] ?? {}}
-        {@const isOpen = cardState.open === true}
-        <li class="rounded border border-default bg-surface overflow-hidden">
-          <button
-            type="button"
-            onclick={() => toggleCardOpen(r.qid)}
-            class="w-full text-left p-3 flex items-start gap-3 hover:bg-bg/30 transition-colors"
-          >
-            <div class="flex-1 min-w-0">
-              <div class="text-sm text-text">{shortText(r.q.question_text, 100)}</div>
-              <div class="text-[11px] text-dim mt-1 flex items-center gap-2 flex-wrap">
-                {#if r.q.subject}<span>{r.q.subject}</span>{/if}
-                {#if r.q.scope}<span>· {r.q.scope}</span>{/if}
-                {#if r.q.exam_round}<span>· {r.q.exam_round}</span>{/if}
-                <span class="ml-auto">
-                  {#if kind === 'correct'}
-                    <span class="text-success">선택 {r.attempt.selected_choice}번 = 정답</span>
-                  {:else if kind === 'wrong'}
-                    <span class="text-error">선택 {r.attempt.selected_choice ?? '?'}번</span>
-                    <span class="text-dim"> · 정답 {r.attempt.correct_choice}번</span>
-                  {:else}
-                    <span class="text-warning">모르겠음</span>
-                    <span class="text-dim"> · 정답 {r.attempt.correct_choice}번</span>
-                  {/if}
-                </span>
-              </div>
-            </div>
-          </button>
-
-          {#if isOpen}
-            <div class="border-t border-default p-3 flex flex-col gap-3 bg-bg/20">
-              <!-- 본문 (수식 포함) -->
-              <div class="text-sm text-text leading-relaxed math-area">{@html renderMathMarkdown(r.q.question_text)}</div>
-
-              {#if r.q.images?.length > 0}
-                <div class="grid grid-cols-1 sm:grid-cols-2 gap-2">
-                  {#each r.q.images as img (img.id)}
-                    <ImgAuth src={img.served_url} class="w-full max-h-60 object-contain rounded border border-default bg-bg/30" />
-                  {/each}
-                </div>
-              {/if}
-
-              <!-- 보기 + 정답 표시 -->
-              <div class="flex flex-col gap-1.5">
-                {#each r.q.choices as ch (ch.number)}
-                  {@const isCorrect = r.attempt.correct_choice === ch.number}
-                  {@const isSelected = r.attempt.selected_choice === ch.number}
-                  <div class="p-2.5 rounded border flex items-start gap-3 text-sm
-                    {isCorrect ? 'border-success bg-success/10 text-text'
-                     : (isSelected && !isCorrect) ? 'border-error bg-error/10 text-text'
-                     : 'border-default bg-surface text-dim'}"
-                  >
-                    <span class="font-semibold w-5 shrink-0">{ch.number}</span>
-                    <span class="flex-1 math-area overflow-x-auto">{@html renderMathMarkdownInline(ch.text)}</span>
-                    {#if isCorrect}<CheckCircle2 size={14} class="text-success shrink-0" />
-                    {:else if isSelected && !isCorrect}<XCircle size={14} class="text-error shrink-0" />
-                    {/if}
-                  </div>
-                {/each}
-              </div>
-
-              <!-- 사용자 입력 해설 (있으면) -->
-              {#if r.q.explanation}
-                <div class="rounded border border-default bg-surface p-3 text-xs text-text math-area">
-                  <div class="text-[10px] text-dim mb-1">사용자 입력 해설</div>
-                  <div class="text-text">{@html renderMathMarkdown(r.q.explanation)}</div>
-                </div>
-              {/if}
-
-              <!-- 카테고리별 추가 액션 -->
-              {#if kind === 'wrong'}
-                {@render aiExplanationBlock(r.qid, cardState)}
-              {:else if kind === 'unsure'}
-                {@render subjectNoteBlock(r, cardState)}
-              {/if}
-            </div>
-          {/if}
-        </li>
-      {/each}
-    </ul>
-  {/if}
-{/snippet}
-
-<!-- 틀린 카드용: PR-3 AI 해설 -->
-{#snippet aiExplanationBlock(qid, st)}
-  {@const data = st.data}
-  {@const isLoaded = !!data?.ai_explanation}
-  <div class="rounded border border-default bg-bg/30 p-3 flex flex-col gap-2">
-    <div class="flex items-center gap-2 flex-wrap">
-      <Sparkles size={14} class="text-accent" />
-      <span class="text-xs font-semibold text-text">AI 풀이</span>
-      {#if data?.is_stale}
-        <span class="text-[10px] text-warning border border-warning/40 rounded px-1.5 py-0.5">stale</span>
-      {/if}
-      {#if data?.from_cache && !data?.is_stale}
-        <span class="text-[10px] text-dim">캐시</span>
-      {/if}
-      <span class="ml-auto flex items-center gap-1.5">
-        {#if !isLoaded}
-          <Button size="sm" variant="ghost" onclick={() => loadAiExplanation(qid, false)} loading={st.loading}>AI 해설 보기</Button>
-        {:else if data?.is_stale}
-          <Button size="sm" onclick={() => loadAiExplanation(qid, true)} loading={st.loading}>다시 생성</Button>
-        {:else if data?.ai_explanation_status === 'failed'}
-          <Button size="sm" onclick={() => loadAiExplanation(qid, true)} loading={st.loading}>다시 시도</Button>
-        {:else}
-          <Button size="sm" variant="ghost" onclick={() => loadAiExplanation(qid, true)} loading={st.loading}>다시 생성</Button>
-        {/if}
-      </span>
-    </div>
-
-    {#if data?.is_stale}
-      <div class="text-[11px] text-warning bg-warning/5 border border-warning/30 rounded px-2 py-1.5 flex items-start gap-1.5">
-        <AlertCircle size={12} class="mt-0.5 shrink-0" />
-        <span>이 풀이는 정답·문제가 수정된 후의 이전 풀이입니다. "다시 생성" 으로 새로 만들 수 있습니다.</span>
-      </div>
-    {/if}
-    {#if st.error}
-      <div class="text-[11px] text-error">{st.error}</div>
-    {/if}
-    {#if isLoaded}
-      <div class="text-xs text-text leading-relaxed prose prose-sm prose-invert max-w-none math-area">
-        {@html renderMathMarkdown(data.ai_explanation)}
-      </div>
-      {#if data.evidence?.length}
-        <details class="text-[10px] text-dim">
-          <summary class="cursor-pointer hover:text-text">참고 근거 {data.evidence.length}건</summary>
-          <ul class="mt-1 flex flex-col gap-1">
-            {#each data.evidence as ev}
-              <li>
-                <span class="text-text">{ev.source_type === 'document' ? '📄' : '❓'} {ev.title}</span>
-                <div class="pl-4 truncate">{ev.snippet}</div>
-              </li>
-            {/each}
-          </ul>
-        </details>
-      {/if}
-    {/if}
-  </div>
-{/snippet}
-
-<!-- 모르겠음 카드용: 분야 설명 (PR-9) -->
-{#snippet subjectNoteBlock(r, st)}
-  {@const data = st.data}
-  {@const isLoaded = !!data?.content}
-  <div class="rounded border border-default bg-bg/30 p-3 flex flex-col gap-2">
-    <div class="flex items-center gap-2 flex-wrap">
-      <BookOpen size={14} class="text-warning" />
-      <span class="text-xs font-semibold text-text">분야 설명</span>
-      <span class="text-[10px] text-dim">
-        {r.q.subject || '(과목 미지정)'}{r.q.scope ? ` · ${r.q.scope}` : ''}
-      </span>
-      {#if data?.from_cache && data?.status === 'ready'}
-        <span class="text-[10px] text-dim">캐시</span>
-      {/if}
-      <span class="ml-auto flex items-center gap-1.5">
-        {#if !isLoaded}
-          <Button size="sm" variant="ghost" onclick={() => loadSubjectNote(r.qid, false)} loading={st.loading}>분야 설명 보기</Button>
-        {:else if data?.status === 'failed'}
-          <Button size="sm" onclick={() => loadSubjectNote(r.qid, true)} loading={st.loading}>다시 시도</Button>
-        {:else}
-          <Button size="sm" variant="ghost" onclick={() => loadSubjectNote(r.qid, true)} loading={st.loading}>다시 생성</Button>
-        {/if}
-      </span>
-    </div>
-
-    {#if st.error}
-      <div class="text-[11px] text-error">{st.error}</div>
-    {/if}
-    {#if isLoaded}
-      <div class="text-xs text-text leading-relaxed prose prose-sm prose-invert max-w-none math-area">
-        {@html renderMathMarkdown(data.content)}
-      </div>
-      {#if data.evidence?.length}
-        <details class="text-[10px] text-dim">
-          <summary class="cursor-pointer hover:text-text">참고 근거 {data.evidence.length}건</summary>
-          <ul class="mt-1 flex flex-col gap-1">
-            {#each data.evidence as ev}
-              <li>
-                <span class="text-text">{ev.source_type === 'document' ? '📄' : '❓'} {ev.title}</span>
-                <div class="pl-4 truncate">{ev.snippet}</div>
-              </li>
-            {/each}
-          </ul>
-        </details>
-      {/if}
-    {/if}
-  </div>
-{/snippet}
@@ -0,0 +1,26 @@
+-- 206_study_quiz_sessions.sql (1/4)
+-- PR-10: 문제풀이 세션 기록 + 이어풀기.
+-- 한 토픽의 한 회차 풀이 = 한 세션. question_ids 는 출제 순서 스냅샷.
+-- 이어풀기: status='in_progress' + cursor (다음 풀 문제 index, 0-based).
+-- 결과 카드: status='done' 후 correct/wrong/unsure_count + finished_at.
+--
+-- status 권장값: in_progress / done / abandoned (강한 enum 미사용).
+
+CREATE TABLE IF NOT EXISTS study_quiz_sessions (
+    id                  BIGSERIAL PRIMARY KEY,
+    user_id             BIGINT NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    study_topic_id      BIGINT NOT NULL REFERENCES study_topics(id) ON DELETE CASCADE,
+    target_per_subject  INT NOT NULL DEFAULT 20,
+    subject_filter      VARCHAR(120),
+    wrong_only          BOOLEAN NOT NULL DEFAULT FALSE,
+    question_ids        JSONB NOT NULL,
+    subject_distribution JSONB NOT NULL DEFAULT '{}'::jsonb,
+    status              VARCHAR(20) NOT NULL DEFAULT 'in_progress',
+    cursor              INT NOT NULL DEFAULT 0,
+    correct_count       INT NOT NULL DEFAULT 0,
+    wrong_count         INT NOT NULL DEFAULT 0,
+    unsure_count        INT NOT NULL DEFAULT 0,
+    finished_at         TIMESTAMPTZ,
+    created_at          TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    updated_at          TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
@@ -0,0 +1,7 @@
+-- 207_study_quiz_sessions_active_uq.sql (2/4)
+-- 한 토픽당 in_progress 세션 1개 강제 (PR-1 partial unique 패턴 동일).
+-- done/abandoned 는 여러 행 허용 (결과 기록 카드 누적).
+
+CREATE UNIQUE INDEX IF NOT EXISTS uq_study_quiz_sessions_active
+    ON study_quiz_sessions (user_id, study_topic_id)
+    WHERE status = 'in_progress';
@@ -0,0 +1,6 @@
+-- 208_attempts_quiz_session.sql (3/4)
+-- attempts 에 quiz_session_id FK (NULL 허용) — 세션 단위 attempt 묶기.
+-- 세션 삭제 시 attempt 자체는 보존(SET NULL) — 이력 테이블 RESTRICT 원칙과 동일 의도.
+
+ALTER TABLE study_question_attempts
+    ADD COLUMN IF NOT EXISTS quiz_session_id BIGINT REFERENCES study_quiz_sessions(id) ON DELETE SET NULL;
@@ -0,0 +1,6 @@
+-- 209_attempts_reviewed_at.sql (4/4)
+-- 결과 화면에서 사용자가 "학습완료" 체크 시 timestamp 박힘. NULL = 미확인.
+-- 결과 카드 헤더 "미확인 N건" 카운트용.
+
+ALTER TABLE study_question_attempts
+    ADD COLUMN IF NOT EXISTS reviewed_at TIMESTAMPTZ;