/* [1] 공통 변수 */
    :root { 
        --point-color: #643fce; 
        --point-light: #f3e5f5;
        --tab-height: 60px;
        --border-color: #e5e5e5;
    }
    
    #sit_info { display: block !important; width: 100%; position: relative; margin-top: 60px; clear: both; font-family: 'Notosans KR', sans-serif; border:none; box-sizing: border-box; }
    .sit_info_inner { width: 100%; max-width: 1300px; margin: 0 auto; }

    /* [2] 탭 네비게이션 (디자인 복구: 폴더형 박스 스타일) */
    #sit_tab_nav { 
        width: 100%; 
        height: var(--tab-height, 60px);
        background: #fff; 
        z-index: 99; 
        box-sizing: border-box;
        /* [수정] sticky 속성으로 변경 */
        position: -webkit-sticky;
        position: sticky;
		top: 100px;
    }
	/* [추가] 탭 네비게이션이 상단에 고정될 때 그림자 효과 */
    #sit_tab_nav.is_stuck {
        box-shadow: 0 4px 10px rgba(0,0,0,0.1);
    }
    
    .tab_list { 
        display: flex; width: 100%; height: 100%; margin: 0; padding: 0; list-style: none; background: #fff; 
    }
    .tab_list li { 
        flex: 1; text-align: center; height: 100%; position: relative;
        border-bottom: 1px solid var(--point-color); /* 전체 하단 보라색 선 */
    }
	.tab_list li.on {
        border-bottom: 1px solid #fff; /* 하단 흰색으로 덮어서 뚫린 효과 */
	}
    
    /* 탭 링크 기본 스타일 (비활성) */
    .tab_list li a { 
        display: flex; align-items: center; justify-content: center; 
        width: 100%; height: 100%; 
        font-size: 15px; color: #888; text-decoration: none; font-weight: 500; 
        background: #f9f9f9; /* 비활성 탭 배경색 */
        border-top: 1px solid #eee; /* 상단 연한 선 */
        border-right: 1px solid #eee; /* 우측 연한 선 */
        border-bottom: none; /* 하단은 컨테이너 선이 보이게 */
        box-sizing: border-box; 
        transition: all 0.2s; 
    }
    .tab_list li:first-child a { border-left: 1px solid #eee; }

    /* [활성화] 탭 스타일 (박스 형태, 하단 뚫림) */
    .tab_list li.on a { 
        color: var(--point-color); 
        font-weight: 800; 
        background: #fff; 
        border-top: 2px solid var(--point-color); /* 상단 굵은 보라색 */
        border-left: 1px solid var(--point-color); /* 좌측 보라색 */
        border-right: 1px solid var(--point-color); /* 우측 보라색 */
        margin-bottom: -1px; /* 부모 테두리 덮기 위해 1px 내림 */
        position: relative; 
        z-index: 2; 
    }

    /* [3] 섹션 공통 */
    .section_anchor { display: block; width: 100%; clear: both; padding-top: 60px; padding-bottom: 60px; }
    
    .info_section_title { font-size: 18px; font-weight: 800; color: #111; margin-bottom: 20px; padding-left: 5px; }
    .sec_header_wrap { width: 100%; border-bottom: 2px solid var(--point-color); padding-bottom: 15px; margin-bottom: 0; }
    .sec_title { font-size: 22px; font-weight: 800; color: #111; display: flex; align-items: center; gap: 8px; margin: 0; }

    /* [4] 필수 표기 정보 테이블 */
    .tbl_ess_info { width: 100%; border-collapse: collapse; margin-bottom: 60px; border-top: 1px solid #e0e0e0; }
    .tbl_ess_info th, .tbl_ess_info td { padding: 18px 20px; border-bottom: 1px solid #f0f0f0; font-size: 14px; text-align: left; vertical-align: middle; }
    .tbl_ess_info th { background: #f9f9f9; font-weight: 700; color: #333; width: 180px; }
    .tbl_ess_info td { color: #555; line-height: 1.6; }

    .skill_badge { display: inline-block; padding: 5px 10px; border-radius: 4px; font-size: 13px; font-weight: 600; margin-right: 6px; margin-bottom: 4px; }
    .sb_blue { background: #e3f2fd; color: #1e88e5; }
    .sb_green { background: #e8f5e9; color: #43a047; }
    .sb_red { background: #ffebee; color: #e53935; }

    .goal_list li { margin-bottom: 6px; display: flex; align-items: center; font-weight: 500; color:#333; }
    .goal_list li i { margin-right: 8px; width: 16px; text-align: center; }
    .comp_list li { margin-bottom: 6px; color: #666; display: flex; align-items: center; }
    .comp_list i { margin-right: 8px; font-size: 12px; color: #999; }

    /* [5] 하단 배너 (영상) */
    .btm_banner { text-align: center; margin: 0 0 60px; padding: 60px 0; background: #fff; }
    .btm_banner h3 { font-size: 24px; font-weight: 800; margin-bottom: 15px; display:flex; align-items:center; justify-content:center; gap:8px; }
    .btm_banner p { font-size: 16px; color: #666; line-height: 1.6; max-width: 800px; margin: 0 auto 40px; word-break: keep-all; }
    .video_preview_box { position: relative; width: 100%; max-width: 1000px; margin: 0 auto; border-radius: 16px; overflow: hidden; cursor: pointer; background: #000; box-shadow: 0 15px 40px rgba(0,0,0,0.1); }
    .video_preview_box img { width: 100%; display: block; opacity: 0.9; transition: opacity 0.3s; }
    .video_preview_box:hover img { opacity: 0.7; }
    .video_overlay_grad { position: absolute; bottom: 0; left: 0; width: 100%; height: 150px; background: linear-gradient(to top, rgba(0,0,0,0.8), transparent); pointer-events: none; }
    .play_btn_icon { position: absolute; top: 50%; left: 50%; transform: translate(-50%, -50%); width: 80px; height: 80px; background: rgba(0,0,0,0.6); border-radius: 50%; display: flex; align-items: center; justify-content: center; backdrop-filter: blur(4px); border: 2px solid rgba(255,255,255,0.3); transition: transform 0.2s, background 0.2s; }
    .play_btn_icon::after { content: ''; display: block; width: 0; height: 0; border-style: solid; border-width: 12px 0 12px 22px; border-color: transparent transparent transparent #fff; margin-left: 4px; }
    .video_caption_text { position: absolute; bottom: 100px; left: 0; width: 100%; text-align: center; color: #fff; font-size: 18px; font-weight: 700; text-shadow: 0 2px 4px rgba(0,0,0,0.5); z-index: 2; }

    /* [6] 활용 가이드 박스 */
    .usage_guide_wrap { border: 1px solid #dcdcdc; border-radius: 20px; overflow: hidden; margin-bottom: 80px; background: #fff; }
    .ug_header { background: #f9f7ff; padding: 25px 0; text-align: center; font-size: 22px; font-weight: 800; color: #111; border-bottom: 1px solid #eee; display: flex; align-items: center; justify-content: center; gap: 10px; }
    .ug_header i { background:#222; color:#fff; width:28px; height:28px; border-radius:50%; font-size:14px; display:flex; align-items:center; justify-content:center; }
    .ug_body { padding: 40px 30px; background: #fff; }
    .ug_list { display: flex; flex-wrap: wrap; gap: 20px; padding: 0; margin: 0; list-style: none; }
    .ug_list li { width: calc(50% - 10px); background: #fff; border: 1px solid var(--border-color); border-radius: 16px; padding: 30px 25px; display: flex; align-items: center; box-sizing: border-box; transition: transform 0.2s; }
    .ug_list li:hover { transform: translateY(-3px); box-shadow: 0 10px 20px rgba(0,0,0,0.05); border-color:var(--point-color); }
    .ug_icon { width: 50px; height: 50px; border-radius: 14px; margin-right: 20px; flex-shrink: 0; display: flex; align-items: center; justify-content: center; font-size: 24px; }
    .icon_blue { background: #e3f2fd; color: #1e88e5; }
    .icon_purple { background: #ede7f6; color: #673ab7; }
    .icon_green { background: #e8f5e9; color: #43a047; }
    .icon_indigo { background: #e8eaf6; color: #3f51b5; }
    .icon_teal { background: #e0f2f1; color: #009688; }
    .ug_text strong { display: block; font-size: 18px; color: #111; margin-bottom: 6px; }
    .ug_text span { display: block; font-size: 14px; color: #666; line-height: 1.5; word-break: keep-all; }

    /* [7] 구매 옵션 섹션 */
    .purchase_options_wrap { margin-bottom: 80px; }
    .po_header { text-align: center; margin-bottom: 50px; }
    .po_header h2 { font-size: 32px; font-weight: 800; color: #111; margin-bottom: 12px; }
    .po_header p { font-size: 16px; color: #666; margin: 0; }
    .po_list { display: flex; gap: 24px; justify-content: center; margin-bottom: 50px; }
    .po_item { flex: 1; background: #fff; border: 1px solid var(--border-color); border-radius: 24px; text-align: center; display: flex; flex-direction: column; transition: all 0.3s; overflow: hidden; padding: 0; position: relative; }
    .po_item:hover { transform: translateY(-8px); box-shadow: 0 20px 40px rgba(0,0,0,0.08); border-color: var(--point-color); }
    .po_content { padding: 40px 30px 40px; flex: 1; display: flex; flex-direction: column; align-items: center; }
    .po_title { font-size: 22px; font-weight: 800; color: #111; margin-bottom: 15px; }
    .po_badge { display: inline-block; padding: 6px 16px; border: 1px solid var(--point-color); color: var(--point-color); border-radius: 30px; font-size: 14px; font-weight: 700; margin-bottom: 25px; background: #fff; }
    .po_price_area { margin-bottom: 35px; min-height: 20px; display:flex; flex-direction:row; justify-content:center; align-items:center; }
    .po_old_price { text-decoration: line-through; color: #999; font-size: 15px; }
    .po_desc { color: #555; font-size: 16px; font-weight: 500; }
    .po_features { display: flex; justify-content: space-between; width: 100%; margin-top: auto; }
    .po_feat { display: flex; flex-direction: column; align-items: center; gap: 12px; flex: 1; }
    .po_feat_icon { width: 56px; height: 56px; background: #f7f7f7; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-size: 22px; color: #777; }
    .po_feat span { font-size: 14px; color: #333; font-weight: 600; white-space: nowrap; }
    .po_btn { display: flex; align-items: center; justify-content: center; width: 100%; height: 70px; background: var(--point-color); color: #fff; font-weight: 700; font-size: 19px; text-decoration: none; margin: 0; border: none; transition: background 0.2s; }
    .po_btn:hover { background: #5000cc; }
    .po_benefit_banner { background: #f9f9f9; border-radius: 20px; padding: 35px; display: flex; align-items: center; justify-content: space-between; }
    .pobb_left { display: flex; flex-direction: column; gap: 15px; width: 35%; }
    .pobb_title { font-size: 18px; font-weight: 800; color: #111; }
    .pobb_btn { display: inline-flex; align-items: center; justify-content: center; gap: 8px; padding: 12px 25px; border: 1px solid var(--point-color); border-radius: 25px; background: #fff; color: var(--point-color); font-size: 14px; font-weight: 700; text-decoration: none; width: fit-content; transition: all 0.2s; }
    .pobb_btn:hover { background: var(--point-color); color: #fff; }
    .pobb_right { display: flex; gap: 35px; width: 60%; }
    .pobb_item { flex: 1; background: #fff; border-radius: 12px; padding: 40px 15px; text-align: center; font-size: 14px; font-weight: 600; color: #333; box-shadow: 0 4px 10px rgba(0,0,0,0.03); display: flex; align-items: center; justify-content: center; min-height: 70px; line-height: 1.4; }

    /* [8] 크리에이터 박스 (시안 유지) */
    .creator_box_wrap { margin-bottom: 80px; }
    .creator_box { background: #f9f9f9; border-radius: 24px; padding: 40px; }
    .cb_title { display: flex; align-items: center; gap: 10px; font-size: 20px; font-weight: 800; color: #111; margin-bottom: 25px; }
    .cb_title i { color: var(--point-color); font-size: 22px; }
    .cb_profile_area { display: flex; align-items: center; margin-bottom: 25px; }
    .cb_img { width: 70px; height: 70px; border-radius: 50%; object-fit: cover; margin-right: 20px; }
    .cb_info { display: flex; flex-direction: column; }
    .cb_info h4 { font-size: 18px; font-weight: 800; color: #111; margin: 0 0 4px; }
    .cb_info span { font-size: 14px; color: #666; font-weight: 500; }
    .btn_creator_detail { display: inline-flex; align-items: center; justify-content: center; padding: 8px 16px; margin-left: 20px; background: #fff; border: 1px solid #ccc; border-radius: 20px; font-size: 13px; color: #333; text-decoration: none; font-weight: 600; transition: all 0.2s; }
    .btn_creator_detail:hover { border-color: #333; }
    .cb_body { margin-top: 20px; }
    .cb_teacher_name { display: block; font-size: 16px; font-weight: 800; color: #111; margin-bottom: 10px; }
    .cb_desc { font-size: 15px; color: #444; line-height: 1.6; margin: 0; }

    /* [9] 리뷰 & FAQ & 환불 */
    .review_summary { display: flex; align-items: center; padding: 0 0 25px; border-bottom: 1px solid var(--border-color); margin-bottom: 0; }
    .rs_score { margin-left: 15px; font-size: 24px; font-weight: 800; display:flex; align-items:center; gap:8px; }
    .star_yellow { color: #ffc107!important; font-size: 20px!important; }
    .star_yellow .fa-star-o { color: #ddd !important; }
    .review_sort { margin-left: auto; font-size: 14px; color: #999; }
    .review_sort span.active { color: #333; font-weight: 700; }
    .review_item { padding: 35px 0; border-bottom: 1px solid var(--border-color); }
    .ri_header { display: flex; align-items: flex-start; margin-bottom: 18px; }
    .ri_profile { width: 40px; height: 40px; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-weight: 700; margin-right: 15px; flex-shrink: 0; font-size: 16px; color:#fff; object-fit: cover; overflow:hidden; }
    .ri_profile img { width:100%!important; height:100%!important; object-fit:cover!important; }
    .ri_meta div { font-size: 16px; font-weight: 700; color: #333; margin-bottom: 4px; display:flex; align-items:center; gap:8px; }
    .ri_meta span { font-size: 14px; color: #888; }
    .ri_meta .star_yellow { font-size: 14px !important; }
    .ri_content { font-size: 15px; color: #333; line-height: 1.6; margin-bottom: 20px; }
    .ri_subject { font-size: 16px; font-weight: 700; color: #111; margin-bottom: 10px; line-height: 1.4; }
    .ri_images { display: flex; gap: 10px; margin-bottom: 20px; }
    .ri_images img { width: 120px; height: 120px; border-radius: 12px; object-fit: cover; }
    .btn_helpful { padding: 8px 16px; border: 1px solid var(--border-color); border-radius: 20px; background: #fff; color: #666; font-size: 13px; cursor: pointer; display: flex; align-items: center; gap: 6px; transition: all 0.2s; }
    .btn_helpful:hover { border-color: #999; color: #333; }
    .bg_green { background-color: #2ecc71; }
    .btn_review_more { display: block; width: 100%; text-align: center; padding: 20px 0; font-size: 16px; font-weight: 700; color: var(--point-color); cursor: pointer; border:none; background:none; }

    .qa_list dl { padding: 25px 0; border-bottom: 1px solid var(--border-color); margin: 0; }
    .qa_list dt { font-size: 18px; font-weight: 700; color: #111; margin-bottom: 12px; display: flex; align-items: flex-start; }
    .qa_list dt span { color: var(--point-color); margin-right: 12px; font-weight: 800; font-size: 18px; line-height:1;}
    .qa_list dd { font-size: 16px; color: #555; line-height: 1.6; margin-left: 0; padding-left: 30px; }
    
    .refund_box { background: #fff; padding: 30px 0; }
    .rf_group { margin-bottom: 35px; }
    .rf_title { font-size: 16px; font-weight: 800; color: #111; margin-bottom: 10px; display: block; }
    .rf_desc { font-size: 15px; color: #555; line-height: 1.6; margin: 0; }

    /* [모바일 반응형] */
    @media (max-width: 991px) {
        #sit_info { padding: 0 0px; margin-top: 40px; }
        .section_anchor { padding-top: 60px; padding-bottom: 60px; }
        .sec_title { font-size: 20px; }
        
        #sit_tab_nav { overflow-x: auto; white-space: nowrap; -webkit-overflow-scrolling: touch; }
        #sit_tab_nav::-webkit-scrollbar { display: none; }
        .tab_list { width: auto; min-width: 100%; display: flex; }
        .tab_list li a { font-size: 15px; }

        .tbl_ess_info { display: block; border-top: none; }
        .tbl_ess_info tbody { display: block; }
        .tbl_ess_info tr { display: block; margin-bottom: 20px; border: 1px solid var(--border-color); border-radius: 12px; overflow: hidden; }
        .tbl_ess_info th { display: block; width: 100%; background: #f9f9f9; border-bottom: 1px solid var(--border-color); padding: 15px 20px; }
        .tbl_ess_info td { display: block; width: 100%; padding: 20px; border-bottom: none; }

        .btm_banner { padding: 40px 0; margin-bottom: 40px; }
        .btm_banner h3 { font-size: 20px; }
        .btm_banner p { font-size: 14px; margin-bottom: 30px; }
        .video_overlay_grad { height: 120px; }
        .play_btn_icon { width: 60px; height: 60px; }
        .play_btn_icon::after { border-width: 10px 0 10px 18px; }
        .video_caption_text { bottom: 20px; font-size: 16px; }

        .usage_guide_wrap { margin-bottom: 60px; }
        .ug_header { font-size: 18px; padding: 20px 0; }
        .ug_body { padding: 20px; }
        .ug_list { gap: 15px; }
        .ug_list li { width: 100%; padding: 25px 20px; }

        .purchase_options_wrap { margin-bottom: 60px; }
        .po_header h2 { font-size: 24px; }
        .po_list { flex-direction: column; gap: 20px; }
        .po_item { transform: none !important; }
        .po_content { padding: 30px 20px 30px; }
        .po_btn { height: 60px; font-size: 17px; }
        .po_benefit_banner { flex-direction: column; align-items: flex-start; gap: 25px; padding: 30px 20px; }
        .pobb_left, .pobb_right { width: 100%; }
        .pobb_right { flex-direction: column; gap: 10px; }
        .pobb_item { min-height: auto; padding: 20px; }

        /* 크리에이터 박스 모바일 대응 */
        .creator_box_wrap { margin-bottom: 60px; }
        .creator_box { padding: 30px 20px; }
        .cb_profile_area { flex-wrap: wrap; }
        .btn_creator_detail { margin-left: 0; margin-top: 10px; width: 100%; text-align: center; }

        .review_summary { flex-direction: column; align-items: flex-start; gap: 15px; }
        .rs_score { margin-left: 0; }
        .review_sort { margin-left: 0; }
        .ri_header { flex-direction: column; }
        .ri_profile { margin-bottom: 15px; }
        .ri_images { overflow-x: auto; white-space: nowrap; -webkit-overflow-scrolling: touch; }
        .ri_images img { width: 100px; height: 100px; flex-shrink: 0; }

        /* FAQ, 환불안내 */
        .qa_list dt { font-size: 16px; }
        .qa_list dd { font-size: 14px; padding-left: 26px; }
        .rf_title { font-size: 15px; }
        .rf_desc { font-size: 14px; }
    }
    .review_item img { border: none !important; }