body {
    margin: 0 auto;
    font-family: 'Inter', sans-serif;
}

/* 전체 컨테이너: max-width를 1920으로 제한 (-> 1280으로 변경)하고 가운데 정렬 */
#divContainer.clsContainer {
    width: 100%;
    height: auto;
    max-width: 1280px;
    margin: 0 auto;
    /*border: 1px solid red;*/
    /* 약간그림자 */
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.05), 0 0 6px rgba(0, 0, 0, 0.03);
    /* 미세한 배경색 차이 */
    background-color: #ffffff;
    border-radius: 8px;
}


/*****************************************
divMain 콘텐츠 CSS
 *****************************************/

/*****************************************
 * 섹션1 스타일 (Primary Grammar)
 *****************************************/
#divSection1.clsSection.clsPgSection1 {
    position: relative;
    width: 100%;
    height: 100vh;
    max-height: 800px;
    overflow: hidden;
}

.clsPgSection1Background {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: url('contents/img/PgSection1-bg.png');
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
}

.clsPgSection1Content {
    padding: 20px;
    color: white;
    max-width: 800px;
    z-index: 2;
    position: relative;
}

.clsPgSection1Title {
    font-size: 32px;
    font-weight: 700;
    margin-bottom: 20px;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
}

.clsPgSection1NumberContainer {
    margin: 30px 0;
}

.clsPgSection1Number {
    font-size: 56px;
    font-weight: 700;
    text-shadow: 0 2px 6px rgba(0, 0, 0, 0.4);
}

    .clsPgSection1Number .clsPgHighlight {
        color: #4CD964;
        font-size: 80px;
        display: inline-block;
        transition: all 0.3s ease;
    }

.clsPgSection1Description {
    font-size: 18px;
    line-height: 1.6;
    margin-bottom: 30px;
    text-shadow: 0 1px 3px rgba(0, 0, 0, 0.3);
}

.clsPgSection1Date {
    font-size: 14px;
    color: rgba(255, 255, 255, 0.8);
    position: absolute;
    bottom: 20px;
    right: 20px;
}

/* 배경에 어두운 오버레이 추가 */
.clsPgSection1Background::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    z-index: 1;
}

/* 배경 이미지 문제 해결을 위한 추가 코드 */
#divSection1.clsPgSection1 {
    background-color: #000;
}

/* 섹션1의 반응형 스타일 */
@media screen and (max-width: 1024px) {
    .clsPgSection1Title {
        font-size: 28px;
    }

    .clsPgSection1Number {
        font-size: 50px;
    }

        .clsPgSection1Number .clsPgHighlight {
            font-size: 70px;
        }

    .clsPgSection1Description {
        font-size: 16px;
    }
}

@media screen and (max-width: 768px) {
    #divSection1.clsPgSection1 {
        max-height: 600px;
    }

    .clsPgSection1Title {
        font-size: 24px;
    }

    .clsPgSection1Number {
        font-size: 44px;
    }

        .clsPgSection1Number .clsPgHighlight {
            font-size: 60px;
        }

    .clsPgSection1Description {
        font-size: 15px;
    }

    .clsPgSection1Date {
        font-size: 12px;
    }
}

@media screen and (max-width: 480px) {
    #divSection1.clsPgSection1 {
        max-height: 500px;
    }

    .clsPgSection1Title {
        font-size: 22px;
    }

    .clsPgSection1Number {
        font-size: 38px;
    }

        .clsPgSection1Number .clsPgHighlight {
            font-size: 52px;
        }

    .clsPgSection1Description {
        font-size: 14px;
    }
}

/*****************************************
 * 섹션2 스타일 (Primary Grammar) - 수정
 *****************************************/
#divSection2.clsSection.clsPrimaryGrammarSection2 {
    background-color: #D3FFE0;
    padding: 80px 20px;
    font-family: 'Inter', sans-serif;
    position: relative;
    display: block;
    margin: 0;
    color: #333;
    width: 100%; /* 명시적 너비 설정 */
    box-sizing: border-box; /* 패딩을 너비에 포함 */
    overflow-x: hidden; /* 가로 스크롤 방지 */
}

/* 컨테이너 너비 제한 확인 */
.clsPrimaryGrammarContainer2 {
    max-width: 1100px;
    margin: 0 auto;
    width: 100%; /* 명시적 너비 설정 */
    box-sizing: border-box; /* 패딩을 너비에 포함 */
}


.clsPrimaryGrammarContent2 {
    text-align: center;
}

.clsPrimaryGrammarSubTitle2 {
    font-size: 18px;
    color: #333;
    margin: 0 0 15px 0;
}

.clsPrimaryGrammarTitle2 {
    font-size: 32px;
    font-weight: 700;
    color: #333;
    margin: 0 0 50px 0;
}

    .clsPrimaryGrammarTitle2 .clsPrimaryGrammarHighlight {
        color: #00A03E;
        font-weight: 700;
    }

.clsPrimaryGrammarImageContainer2 {
    max-width: 600px; /* 이미지 최대 너비 제한 */
    margin: 0 auto;
}

.clsPrimaryGrammarImage2 {
    width: 100%;
    height: auto;
    display: block;
}

/* 반응형 스타일 */
@media screen and (max-width: 1024px) {
    .clsPrimaryGrammarTitle2 {
        font-size: 28px;
    }

    .clsPrimaryGrammarSubTitle2 {
        font-size: 17px;
    }

    .clsPrimaryGrammarImageContainer2 {
        max-width: 500px;
    }
}

@media screen and (max-width: 768px) {
    #divSection2.clsPrimaryGrammarSection2 {
        padding: 60px 20px;
    }

    .clsPrimaryGrammarTitle2 {
        font-size: 24px;
        margin-bottom: 40px;
    }

    .clsPrimaryGrammarSubTitle2 {
        font-size: 16px;
    }

    .clsPrimaryGrammarImageContainer2 {
        max-width: 400px;
    }
}

@media screen and (max-width: 480px) {
    #divSection2.clsPrimaryGrammarSection2 {
        padding: 50px 15px;
    }

    .clsPrimaryGrammarTitle2 {
        font-size: 22px;
        margin-bottom: 30px;
    }

    .clsPrimaryGrammarSubTitle2 {
        font-size: 15px;
    }

    .clsPrimaryGrammarImageContainer2 {
        max-width: 90%;
    }
}



/*****************************************
 * 섹션3 스타일 (Primary Grammar)
 *****************************************/
#divSection3.clsSection.clsPrimaryGrammarSection3 {
    position: relative;
    margin: 0;
    padding: 80px 20px;
    background-color: #f9f9f9;
    font-family: 'Inter', sans-serif;
    display: block;
    color: #333;
    background-image: none;
}

.clsPrimaryGrammarContainer3 {
    max-width: 1100px;
    margin: 0 auto;
}

.clsPrimaryGrammarContent3 {
    display: flex;
    align-items: center;
    gap: 60px;
}

/* 왼쪽 텍스트 영역 */
.clsPrimaryGrammarTextColumn3 {
    flex: 1;
    position: relative;
    padding-left: 15px;
    text-align: left;
}

.clsPrimaryGrammarGreenBar {
    width: 35px;
    height: 4px;
    background-color: #4CD964;
    margin-bottom: 25px;
    position: absolute;
    top: -5px;
    left: 15px;
}

.clsPrimaryGrammarTitle3 {
    font-size: 28px;
    font-weight: 700;
    color: #333;
    margin: 0 0 25px 0;
    line-height: 1.4;
    text-align: left;
}

    .clsPrimaryGrammarTitle3 .clsPrimaryGrammarHighlight {
        color: #4CD964;
        font-weight: 700;
    }

.clsPrimaryGrammarDescription3 {
    font-size: 16px;
    line-height: 1.6;
    color: #555;
    text-align: left;
}

/* 오른쪽 비디오 영역 */
.clsPrimaryGrammarVideoColumn3 {
    flex: 1;
}

.clsPrimaryGrammarVideoWrapper3 {
    position: relative;
    width: 100%;
    border-radius: 15px;
    overflow: hidden;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.1);
    background-color: #000;
    aspect-ratio: 16 / 9;
    border: 2px solid #333;
}

.clsPrimaryGrammarVideoThumbnail3 {
    position: relative;
    width: 100%;
    height: 100%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: #000;
}

/* 썸네일 이미지 스타일 */
.clsPrimaryGrammarThumbnailImage3 {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover; /* 이미지가 비율을 유지하며 영역을 채우도록 */
    z-index: 1; /* Play 버튼이 위에 오도록 */
}

.clsPrimaryGrammarPlayButton3 {
    transition: transform 0.3s ease;
    z-index: 2; /* 이미지가 위에 오도록 */
}

.clsPrimaryGrammarVideoThumbnail3:hover .clsPrimaryGrammarPlayButton3 {
    transform: scale(1.1);
}

/* 비디오 플레이어 모달 스타일 */
.clsPrimaryGrammarVideoPlayerModal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.9);
    z-index: 1100;
    align-items: center;
    justify-content: center;
}

.clsPrimaryGrammarVideoPlayerContainer {
    position: relative;
    width: 90%;
    max-width: 600px; /*비디오 잘림 900px -> 600px로 */
    background-color: #000;
    border-radius: 8px;
    overflow: hidden;
}

.clsPrimaryGrammarCloseVideoPlayer {
    position: absolute;
    top: 10px;
    right: 10px;
    background: rgba(0, 0, 0, 0.5);
    border: none;
    color: white;
    font-size: 24px;
    width: 36px;
    height: 36px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    z-index: 10;
    transition: background 0.3s ease;
}

    .clsPrimaryGrammarCloseVideoPlayer:hover {
        background-color: rgba(255, 255, 255, 0.2);
    }

.clsPrimaryGrammarCustomVideoPlayer {
    position: relative;
    width: 100%;
}

.clsPrimaryGrammarVideoElement {
    width: 100%;
    display: block;
}

.clsPrimaryGrammarVideoControls {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    background: linear-gradient(to top, rgba(0, 0, 0, 0.7), transparent);
    padding: 15px;
    display: flex;
    align-items: center;
    transition: opacity 0.3s ease;
    opacity: 0; /* Initially hidden */
}

.clsPrimaryGrammarPlayPauseBtn {
    width: 36px;
    height: 36px;
    background-color: rgba(76, 217, 100, 0.7);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    margin-right: 15px;
    transition: background-color 0.3s ease;
}

    .clsPrimaryGrammarPlayPauseBtn:hover {
        background-color: rgba(76, 217, 100, 1);
    }

.clsPrimaryGrammarPauseIcon {
    display: none;
}

.clsPrimaryGrammarProgressBarContainer {
    flex: 1;
    margin: 0 15px;
}

.clsPrimaryGrammarProgressBar {
    height: 6px;
    background-color: rgba(255, 255, 255, 0.3);
    border-radius: 3px;
    position: relative;
    cursor: pointer;
}

.clsPrimaryGrammarProgress {
    height: 100%;
    background-color: #4CD964;
    border-radius: 3px;
    width: 0;
}

.clsPrimaryGrammarTimeDisplay {
    color: white;
    font-size: 14px;
    margin: 0 15px;
    min-width: 90px;
    text-align: center;
}

.clsPrimaryGrammarVolumeContainer {
    display: flex;
    align-items: center;
    margin-right: 15px;
}

.clsPrimaryGrammarVolumeBtn {
    cursor: pointer;
    margin-right: 10px;
}

.clsPrimaryGrammarVolumeSlider {
    width: 60px;
    height: 6px;
    background-color: rgba(255, 255, 255, 0.3);
    border-radius: 3px;
    position: relative;
    cursor: pointer;
}

.clsPrimaryGrammarVolumeProgress {
    height: 100%;
    background-color: #4CD964;
    border-radius: 3px;
    width: 100%;
}

.clsPrimaryGrammarFullscreenBtn {
    cursor: pointer;
}

/* 섹션3 반응형 스타일 */
@media screen and (max-width: 1024px) {
    .clsPrimaryGrammarContent3 {
        gap: 40px;
    }

    .clsPrimaryGrammarTitle3 {
        font-size: 24px;
    }

    .clsPrimaryGrammarDescription3 {
        font-size: 15px;
    }

    .clsPrimaryGrammarVideoControls {
        padding: 12px;
    }
}

@media screen and (max-width: 768px) {
    #divSection3.clsPrimaryGrammarSection3 {
        padding: 60px 20px;
    }

    .clsPrimaryGrammarContent3 {
        flex-direction: column;
        gap: 40px;
    }

    .clsPrimaryGrammarTextColumn3 {
        text-align: center;
        padding-left: 0;
        order: 2; /* 모바일에서 텍스트를 아래로 */
    }

    .clsPrimaryGrammarVideoColumn3 {
        order: 1; /* 모바일에서 비디오를 위로 */
        width: 100%;
    }

    .clsPrimaryGrammarGreenBar {
        position: relative;
        margin: 0 auto 20px;
        left: 0;
    }

    .clsPrimaryGrammarTitle3 {
        font-size: 22px;
        text-align: center;
    }

    .clsPrimaryGrammarVideoWrapper3 {
        max-width: 100%;
        margin: 0 auto;
    }

    .clsPrimaryGrammarDescription3 {
        font-size: 15px;
        text-align: center;
    }

    .clsPrimaryGrammarVolumeContainer {
        display: none; /* 모바일에서는 볼륨 컨트롤 숨김 */
    }

    .clsPrimaryGrammarTimeDisplay {
        font-size: 12px;
        min-width: 70px;
    }
}

@media screen and (max-width: 480px) {
    #divSection3.clsPrimaryGrammarSection3 {
        padding: 50px 15px;
    }

    .clsPrimaryGrammarTitle3 {
        font-size: 20px;
    }

    .clsPrimaryGrammarDescription3 {
        font-size: 14px;
    }

    .clsPrimaryGrammarGreenBar {
        width: 40px;
        height: 5px;
    }

    .clsPrimaryGrammarPlayButton3 svg {
        width: 60px;
        height: 60px;
    }

    .clsPrimaryGrammarVideoControls {
        padding: 10px;
    }

    .clsPrimaryGrammarPlayPauseBtn {
        width: 30px;
        height: 30px;
    }
}


/*****************************************
 * 섹션4 스타일 (Primary Grammar)
 *****************************************/
#divSection4.clsSection.clsPrimaryGrammarSection4 {
    width: 100%;
    box-sizing: border-box;
    overflow-x: hidden;
    font-family: 'Inter', sans-serif;
}

/* 타이틀 영역 */
.clsPrimaryGrammarTitleArea4 {
    background-color: #00CE4E;
    padding: 30px 20px;
    text-align: center;
}

.clsPrimaryGrammarMainTitle4 {
    color: white;
    font-size: 28px;
    font-weight: 700;
    margin: 0;
}

/* 서비스 아이템 영역 */
.clsPrimaryGrammarServicesArea4 {
    background-color: #EBEBEB;
    padding: 60px 20px;
}

.clsPrimaryGrammarServicesContainer4 {
    max-width: 1100px;
    margin: 0 auto;
    display: flex;
    justify-content: space-around;
    flex-wrap: wrap;
    gap: 30px;
}

/* 서비스 아이템 */
.clsPrimaryGrammarServiceItem4 {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    flex: 0 0 calc(25% - 22.5px);
    max-width: 250px;
    margin-bottom: 20px;
    box-sizing: border-box;
}

.clsPrimaryGrammarServiceIcon4 {
    margin-bottom: 20px;
    background-color: white;
    border-radius: 50%;
    padding: 20px;
    display: flex;
    justify-content: center;
    align-items: center;
    box-sizing: border-box;
}

/* 새로운 이미지 아이콘 스타일 */
.clsPrimaryGrammarServiceIconImg4 {
    width: 100px;
    height: 100px;
    object-fit: contain;
}

.clsPrimaryGrammarServiceSubtitle4 {
    font-size: 14px;
    color: #666;
    margin: 0 0 8px 0;
    font-weight: 500;
}

.clsPrimaryGrammarServiceTitle4 {
    font-size: 18px;
    color: #333;
    margin: 0;
    font-weight: 700;
}

/* 반응형 스타일 */
@media screen and (max-width: 1024px) {
    .clsPrimaryGrammarMainTitle4 {
        font-size: 26px;
    }

    .clsPrimaryGrammarServicesContainer4 {
        gap: 20px;
    }

    .clsPrimaryGrammarServiceItem4 {
        flex-basis: calc(25% - 15px);
        max-width: 220px;
    }

    .clsPrimaryGrammarServiceIcon4 {
        padding: 18px;
    }

    .clsPrimaryGrammarServiceIconImg4 {
        width: 90px;
        height: 90px;
    }

    .clsPrimaryGrammarServiceTitle4 {
        font-size: 17px;
    }
}

/* New breakpoint for 2 columns */
@media screen and (max-width: 991px) {
    .clsPrimaryGrammarServicesContainer4 {
        gap: 20px;
        justify-content: center;
    }

    .clsPrimaryGrammarServiceItem4 {
        flex-basis: calc(50% - 10px);
        max-width: 300px;
    }

    .clsPrimaryGrammarServiceIcon4 {
        padding: 16px;
    }

    .clsPrimaryGrammarServiceIconImg4 {
        width: 85px;
        height: 85px;
    }

    .clsPrimaryGrammarServiceTitle4 {
        font-size: 16px;
    }

    .clsPrimaryGrammarServiceSubtitle4 {
        font-size: 13px;
    }
}

@media screen and (max-width: 768px) {
    .clsPrimaryGrammarMainTitle4 {
        font-size: 24px;
    }

    .clsPrimaryGrammarServicesContainer4 {
        gap: 15px;
    }

    .clsPrimaryGrammarServiceItem4 {
        flex: 0 0 calc(50% - 7.5px);
        max-width: none;
    }

    .clsPrimaryGrammarServiceIcon4 {
        padding: 15px;
    }

    .clsPrimaryGrammarServiceIconImg4 {
        width: 80px;
        height: 80px;
    }

    .clsPrimaryGrammarServiceSubtitle4 {
        font-size: 13px;
    }

    .clsPrimaryGrammarServiceTitle4 {
        font-size: 16px;
    }
}

@media screen and (max-width: 600px) {
    .clsPrimaryGrammarServicesContainer4 {
        flex-wrap: wrap;
        justify-content: center;
        gap: 20px;
    }

    .clsPrimaryGrammarServiceItem4 {
        flex: 0 0 calc(50% - 10px);
        min-width: auto;
        max-width: none;
    }

    .clsPrimaryGrammarServiceIcon4 {
        padding: 12px;
    }

    .clsPrimaryGrammarServiceIconImg4 {
        width: 70px;
        height: 70px;
    }
}

@media screen and (max-width: 480px) {
    .clsPrimaryGrammarTitleArea4 {
        padding: 25px 15px;
    }

    .clsPrimaryGrammarMainTitle4 {
        font-size: 22px;
    }

    .clsPrimaryGrammarServicesArea4 {
        padding: 40px 15px;
    }

    .clsPrimaryGrammarServicesContainer4 {
        gap: 15px;
    }

    .clsPrimaryGrammarServiceItem4 {
        flex: 0 0 calc(50% - 7.5px);
        min-width: auto;
        max-width: none;
        margin-bottom: 15px;
    }

    .clsPrimaryGrammarServiceIcon4 {
        padding: 10px;
    }

    .clsPrimaryGrammarServiceIconImg4 {
        width: 65px;
        height: 65px;
    }

    .clsPrimaryGrammarServiceSubtitle4 {
        font-size: 12px;
    }

    .clsPrimaryGrammarServiceTitle4 {
        font-size: 15px;
    }
}



/*****************************************
 * 섹션5 스타일 (Primary Grammar)
 *****************************************/
#divSection5.clsSection.clsPrimaryGrammarSection5 {
    width: 100%;
    box-sizing: border-box;
    overflow-x: hidden;
    font-family: 'Inter', sans-serif;
    background: linear-gradient(to bottom, #E4FFEF 0%, #E4FFEF 100%);
    padding: 80px 0 100px;
}

.clsPrimaryGrammarContainer5 {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 20px;
}

/* 타이틀 영역 */
.clsPrimaryGrammarTitleArea5 {
    text-align: center;
    margin-bottom: 50px;
}

.clsPrimaryGrammarSubTitle5 {
    font-size: 18px;
    color: #333;
    margin: 0 0 15px 0;
}

.clsPrimaryGrammarTitle5 {
    font-size: 32px;
    font-weight: 700;
    color: #333;
    margin: 0;
}

.clsPrimaryGrammarHighlight5 {
    color: #00CE4E;
}

/* 슬라이드 영역 */
.clsPrimaryGrammarSlideArea5 {
    margin-bottom: 60px;
}

.clsPrimaryGrammarSlideContainer5 {
    position: relative;
    max-width: 800px;
    margin: 0 auto;
}

.clsPrimaryGrammarSlideWrapper5 {
    position: relative;
    overflow: hidden;
    border-radius: 20px;
}

.clsPrimaryGrammarSlide5 {
    display: none;
    position: relative;
}

    .clsPrimaryGrammarSlide5.active {
        display: block;
    }

.clsPrimaryGrammarSlideImage5 {
    width: 100%;
    height: auto;
    display: block;
    border-radius: 20px;
    /*border: 2px solid #333;*/
}

.clsPrimaryGrammarSlideBubble5 {
    position: absolute;
    top: 20px;
    left: 20px;
    background-color: #fff;
    border: 2px solid #00CE4E;
    border-radius: 15px;
    padding: 15px;
    max-width: 200px;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
}

    .clsPrimaryGrammarSlideBubble5 p {
        margin: 0;
        font-size: 16px;
        line-height: 1.4;
        color: #333;
        font-weight: 500;
    }

.clsPrimaryGrammarSlideControls5 {
    display: flex;
    justify-content: center;
    align-items: center;
    margin-top: 20px;
}

.clsPrimaryGrammarSlidePrev5,
.clsPrimaryGrammarSlideNext5 {
    background: none;
    border: none;
    cursor: pointer;
    padding: 0;
}

.clsPrimaryGrammarSlideDots5 {
    display: flex;
    justify-content: center;
    align-items: center;
    margin: 0 20px;
}

.clsPrimaryGrammarSlideDot5 {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background-color: #ccc;
    margin: 0 5px;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

    .clsPrimaryGrammarSlideDot5.active {
        background-color: #00CE4E;
    }

/* 탭 영역 */
.clsPrimaryGrammarTabArea5 {
    margin-bottom: 50px;
    max-width: 900px;
    margin-left: auto;
    margin-right: auto;
}

.clsPrimaryGrammarTabButtons5 {
    display: flex;
    justify-content: center;
    margin-bottom: 30px;
    position: relative;
    z-index: 1;
    width: 100%;
    box-sizing: border-box;
}

.clsPrimaryGrammarTabButton5 {
    background: none;
    border: none;
    cursor: pointer;
    padding: 0;
    flex: 1;
    transition: all 0.3s ease;
    position: relative;
}

.clsPrimaryGrammarTabButtonGreen5 {
    background-color: #888888;
    color: white;
    border-radius: 15px 0 0 0;
    height: 100%;
    padding: 15px 20px;
    position: relative;
    border: none;
}

.clsPrimaryGrammarTabButtonGray5 {
    background-color: #888888;
    color: white;
    border-radius: 0 15px 0 0;
    height: 100%;
    padding: 15px 20px;
    position: relative;
    border: none;
}

.clsPrimaryGrammarTabButtonGreen5::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 0;
    height: 0;
    border-left: 45px solid transparent;
    border-right: 45px solid transparent;
    border-top: 10px solid #888888;
}

.clsPrimaryGrammarTabButtonGray5::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 0;
    height: 0;
    border-left: 45px solid transparent;
    border-right: 45px solid transparent;
    border-top: 10px solid #888888;
}

.clsPrimaryGrammarTabButtonContent5 {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 10px;
}

.clsPrimaryGrammarTabButtonText5 {
    font-size: 14px;
    line-height: 1.4;
    font-weight: normal;
    text-align: left;
    flex: 1;
}

.clsPrimaryGrammarTabButtonGrade5 {
    font-size: 28px;
    font-weight: 700;
    line-height: 1.2;
    text-align: right;
}

.clsPrimaryGrammarTabContents5 {
    background-color: white;
    /*border-radius: 20px;*/
    padding: 40px 30px;
    text-align: center;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.05);
    position: relative;
    z-index: 0;
    margin-top: 10px;
    width: 100%;
    box-sizing: border-box;
}

.clsPrimaryGrammarTabContent5 {
    display: none;
}

    .clsPrimaryGrammarTabContent5.active {
        display: block;
    }

    /*.clsPrimaryGrammarTabContent5 p {
        font-size: 16px;
        line-height: 1.7;
        color: #333;
        margin: 0;
    }*/

/* 버튼 영역 */
.clsPrimaryGrammarButtonArea5 {
    text-align: center; 
    margin-top: -25px;
    position: relative;
    z-index: 2;
}

.clsPrimaryGrammarCurriculumButton5 {
    background-color: #000;
    color: white;
    border: none;
    border-radius: 30px;
    padding: 13px 28px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.2);
    transition: all 0.3s ease;
}

    .clsPrimaryGrammarCurriculumButton5:hover {
        background-color: #222;
        transform: translateY(-2px);
        box-shadow: 0 6px 15px rgba(0, 0, 0, 0.25);
    }

/* 반응형 스타일 */
@media screen and (max-width: 1024px) {
    .clsPrimaryGrammarTabButtonText5 {
        font-size: 13px;
    }

    .clsPrimaryGrammarTabButtonGrade5 {
        font-size: 24px;
    }

    .clsPrimaryGrammarTabButtonGreen5::after,
    .clsPrimaryGrammarTabButtonGray5::after {
        bottom: -8px;
        border-left-width: 42px;
        border-right-width: 42px;
        border-top-width: 8px;
    }

    .clsPrimaryGrammarTabContents5 {
        /*padding: 35px 25px;*/
    }

    .clsPrimaryGrammarTabContent5 p {
        font-size: 15px;
    }
}

@media screen and (max-width: 768px) {
    .clsPrimaryGrammarTabButtons5 {
        flex-direction: row;
        margin-left: auto;
        margin-right: auto;
        margin-bottom: 20px;
    }

    .clsPrimaryGrammarTabButtonGreen5,
    .clsPrimaryGrammarTabButtonGray5 {
        padding: 12px 15px;
    }

    .clsPrimaryGrammarTabButtonContent5 {
        gap: 5px;
    }

    .clsPrimaryGrammarTabButtonText5 {
        font-size: 12px;
    }

    .clsPrimaryGrammarTabButtonGrade5 {
        font-size: 22px;
    }

    .clsPrimaryGrammarTabButtonGreen5::after,
    .clsPrimaryGrammarTabButtonGray5::after {
        bottom: -7px;
        border-left-width: 40px;
        border-right-width: 40px;
        border-top-width: 7px;
    }

    .clsPrimaryGrammarTabContents5 {
        padding: 30px 20px;
        margin: 0 auto;
    }

    .clsPrimaryGrammarCurriculumButton5 {
        padding: 12px 25px;
        font-size: 15px;
    }

    .clsPrimaryGrammarTabContent5 p {
        font-size: 14px;
    }
}

@media screen and (max-width: 480px) {
    .clsPrimaryGrammarTitle5 {
        font-size: 23px;
    }
    .clsPrimaryGrammarTabButtonGreen5,
    .clsPrimaryGrammarTabButtonGray5 {
        padding: 10px 10px;
    }

    .clsPrimaryGrammarTabButtonContent5 {
        flex-direction: column;
        align-items: center;
        gap: 3px;
    }

    .clsPrimaryGrammarTabButtonText5 {
        font-size: 11px;
        text-align: center;
    }

    .clsPrimaryGrammarTabButtonGrade5 {
        font-size: 20px;
        text-align: center;
    }

    .clsPrimaryGrammarTabButtonGreen5::after,
    .clsPrimaryGrammarTabButtonGray5::after {
        bottom: -6px;
        border-left-width: 40px;
        border-right-width: 40px;
        border-top-width: 6px;
    }

    .clsPrimaryGrammarTabContents5 {
        padding: 25px 15px;
    }

    .clsPrimaryGrammarCurriculumButton5 {
        padding: 10px 20px;
        font-size: 14px;
    }

    .clsPrimaryGrammarTabContent5 p {
        font-size: 13px;
    }
}

/*****************************************
 * 섹션6 스타일 (Primary Grammar - 비디오 섹션)
 *****************************************/
#divSection6.clsSection.clsPrimaryGrammarSection6 {
    background-color: #f8f8f8;
    padding: 80px 20px;
    font-family: 'Inter', sans-serif;
    width: 100%;
    box-sizing: border-box;
    overflow-x: hidden;
}

.clsPrimaryGrammarSection6Container {
    max-width: 1100px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.clsPrimaryGrammarSection6Header {
    text-align: center;
    margin-bottom: 50px;
}

.clsPrimaryGrammarSection6Title {
    font-size: 28px;
    font-weight: 700;
    color: #333;
    margin: 0;
}

.clsPrimaryGrammarHighlight6 {
    color: #4CD964;
    font-weight: 700;
}

.clsPrimaryGrammarVideoGrid {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 30px;
    width: 100%;
    margin-bottom: 40px;
}

.clsPrimaryGrammarVideoItem {
    width: calc(50% - 15px);
    max-width: 450px;
}

.clsPrimaryGrammarVideoThumbnail {
    position: relative;
    width: 100%;
    border-radius: 12px;
    overflow: hidden;
    cursor: pointer;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

    .clsPrimaryGrammarVideoThumbnail:hover {
        transform: translateY(-5px);
        box-shadow: 0 8px 20px rgba(0, 0, 0, 0.15);
    }

        .clsPrimaryGrammarVideoThumbnail:hover .clsPrimaryGrammarPlayButton svg circle {
            fill-opacity: 1;
        }

.clsPrimaryGrammarVideoImg {
    width: 100%;
    height: auto;
    display: block;
}

.clsPrimaryGrammarPlayButton {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    transition: all 0.3s ease;
}

.clsPrimaryGrammarVideoTitle {
    font-size: 16px;
    color: #333;
    margin: 15px 0 0 0;
    text-align: center;
}

.clsPrimaryGrammarMoreButtonContainer {
    margin-top: 30px;
    text-align: center;
}

.clsPrimaryGrammarMoreButton {
    background: none;
    border: none;
    display: flex;
    flex-direction: column;
    align-items: center;
    cursor: pointer;
    padding: 0;
    transition: transform 0.3s ease;
}

    .clsPrimaryGrammarMoreButton:hover {
        transform: translateY(-3px);
    }

.clsPrimaryGrammarMoreIcon {
    width: 40px;
    height: auto;
    margin-bottom: 10px;
}

.clsPrimaryGrammarMoreButton span {
    font-size: 16px;
    color: #333;
}

/* 비디오 모달 스타일 */
.clsPrimaryGrammarVideoModal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.85);
    z-index: 1000;
    overflow-y: auto;
}

.clsPrimaryGrammarModalContent {
    background-color: white;
    margin: 50px auto;
    padding: 20px;
    width: 90%;
    max-width: 1000px;
    border-radius: 10px;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.3);
}

.clsPrimaryGrammarModalHeader {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-bottom: 15px;
    border-bottom: 1px solid #eee;
    margin-bottom: 20px;
}

    .clsPrimaryGrammarModalHeader h3 {
        font-size: 24px;
        color: #333;
        margin: 0;
    }

.clsPrimaryGrammarCloseModal {
    background: none;
    border: none;
    font-size: 28px;
    color: #666;
    cursor: pointer;
    transition: color 0.3s ease;
}

    .clsPrimaryGrammarCloseModal:hover {
        color: #4CD964;
    }

.clsPrimaryGrammarModalBody {
    padding: 10px 0;
}

.clsPrimaryGrammarModalVideoGrid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
}

.clsPrimaryGrammarModalVideoItem {
    width: 100%;
}

/* 커스텀 비디오 플레이어 모달 */
.clsPrimaryGrammarVideoPlayerModal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.9);
    z-index: 1100;
    align-items: center;
    justify-content: center;
}

    /* 모달이 표시될 때 적용할 스타일 */
    .clsPrimaryGrammarVideoPlayerModal.active {
        display: flex !important;
        align-items: center !important;
        justify-content: center !important;
    }

.clsPrimaryGrammarVideoPlayerContainer {
    position: relative;
    width: 90%;
    max-width: 600px; /*비디오 잘림 900px -> 600px로 */
    background-color: #000;
    border-radius: 8px;
    overflow: hidden;
}

.clsPrimaryGrammarCloseVideoPlayer {
    position: absolute;
    top: 10px;
    right: 10px;
    background: rgba(0, 0, 0, 0.5);
    border: none;
    color: white;
    font-size: 24px;
    width: 36px;
    height: 36px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    z-index: 10;
    transition: background 0.3s ease;
}

    .clsPrimaryGrammarCloseVideoPlayer:hover {
        background-color: rgba(255, 255, 255, 0.2);
    }

.clsPrimaryGrammarCustomVideoPlayer {
    position: relative;
    width: 100%;
}

.clsPrimaryGrammarVideoElement {
    width: 100%;
    display: block;
}

.clsPrimaryGrammarVideoControls {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    background: linear-gradient(to top, rgba(0, 0, 0, 0.7), transparent);
    padding: 15px;
    display: flex;
    align-items: center;
    transition: opacity 0.3s ease;
    opacity: 0;
}

.clsPrimaryGrammarPlayPauseBtn {
    width: 36px;
    height: 36px;
    background-color: rgba(76, 217, 100, 0.7);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    margin-right: 15px;
    transition: background-color 0.3s ease;
}

    .clsPrimaryGrammarPlayPauseBtn:hover {
        background-color: rgba(76, 217, 100, 1);
    }

.clsPrimaryGrammarPauseIcon {
    display: none;
}

.clsPrimaryGrammarProgressBarContainer {
    flex: 1;
    margin: 0 15px;
}

.clsPrimaryGrammarProgressBar {
    height: 6px;
    background-color: rgba(255, 255, 255, 0.3);
    border-radius: 3px;
    position: relative;
    cursor: pointer;
}

.clsPrimaryGrammarProgress {
    height: 100%;
    background-color: #4CD964;
    border-radius: 3px;
    width: 0;
}

.clsPrimaryGrammarTimeDisplay {
    color: white;
    font-size: 14px;
    margin: 0 15px;
    min-width: 90px;
    text-align: center;
}

.clsPrimaryGrammarVolumeContainer {
    display: flex;
    align-items: center;
    margin-right: 15px;
}

.clsPrimaryGrammarVolumeBtn {
    cursor: pointer;
    margin-right: 10px;
}

.clsPrimaryGrammarVolumeSlider {
    width: 60px;
    height: 6px;
    background-color: rgba(255, 255, 255, 0.3);
    border-radius: 3px;
    position: relative;
    cursor: pointer;
}

.clsPrimaryGrammarVolumeProgress {
    height: 100%;
    background-color: #4CD964;
    border-radius: 3px;
    width: 100%;
}

.clsPrimaryGrammarFullscreenBtn {
    cursor: pointer;
}

/* 반응형 스타일 */
@media screen and (max-width: 1024px) {
    #divSection6.clsPrimaryGrammarSection6 {
        padding: 70px 20px;
    }

    .clsPrimaryGrammarVideoGrid {
        gap: 20px;
    }

    .clsPrimaryGrammarVideoTitle {
        font-size: 15px;
    }

    .clsPrimaryGrammarModalVideoGrid {
        gap: 20px;
    }

    .clsPrimaryGrammarVideoControls {
        padding: 12px;
    }

    .clsPrimaryGrammarPlayPauseBtn {
        width: 32px;
        height: 32px;
        margin-right: 10px;
    }

    .clsPrimaryGrammarTimeDisplay {
        font-size: 13px;
        min-width: 80px;
    }

    .clsPrimaryGrammarVolumeSlider {
        width: 50px;
    }
}

@media screen and (max-width: 768px) {
    #divSection6.clsPrimaryGrammarSection6 {
        padding: 60px 20px;
    }

    .clsPrimaryGrammarSection6Title {
        font-size: 24px;
    }

    .clsPrimaryGrammarVideoGrid {
        flex-direction: column;
        align-items: center;
    }

    .clsPrimaryGrammarVideoItem {
        width: 90%;
        max-width: 450px;
    }

    .clsPrimaryGrammarModalVideoGrid {
        grid-template-columns: 1fr;
    }

    .clsPrimaryGrammarModalHeader h3 {
        font-size: 20px;
    }

    .clsPrimaryGrammarVideoControls {
        padding: 10px;
    }

    .clsPrimaryGrammarPlayPauseBtn {
        width: 30px;
        height: 30px;
        margin-right: 8px;
    }

    .clsPrimaryGrammarTimeDisplay {
        font-size: 12px;
        min-width: 70px;
        margin: 0 8px;
    }

    .clsPrimaryGrammarVolumeContainer {
        margin-right: 8px;
    }

    .clsPrimaryGrammarVolumeSlider {
        width: 40px;
    }
}

@media screen and (max-width: 480px) {
    #divSection6.clsPrimaryGrammarSection6 {
        padding: 50px 15px;
    }

    .clsPrimaryGrammarSection6Title {
        font-size: 22px;
    }

    .clsPrimaryGrammarVideoTitle {
        font-size: 14px;
    }

    .clsPrimaryGrammarMoreIcon {
        width: 30px;
    }

    .clsPrimaryGrammarMoreButton span {
        font-size: 14px;
    }

    .clsPrimaryGrammarModalContent {
        margin: 30px auto;
        padding: 15px;
    }

    .clsPrimaryGrammarVideoControls {
        padding: 8px;
    }

    .clsPrimaryGrammarPlayPauseBtn {
        width: 28px;
        height: 28px;
        margin-right: 6px;
    }

    .clsPrimaryGrammarProgressBarContainer {
        margin: 0 8px;
    }

    .clsPrimaryGrammarTimeDisplay {
        font-size: 11px;
        min-width: 60px;
        margin: 0 6px;
    }

    .clsPrimaryGrammarVolumeContainer {
        display: none;
    }
}

/* New Hover Style - Only color change */
.clsPrimaryGrammarTabButton5:hover {
    background-color: #4CD964; 
    color: white;
    border: none; 
}

/* Ensure active fin color matches active background */
.clsPrimaryGrammarTabButton5.active::after {
    border-top-color: #4CD964;
}

/* Style for the inner GREEN div when its parent button is ACTIVE */
/* (This might be redundant if base green is already #00CE4E, but ensures consistency) */
.clsPrimaryGrammarTabButton5.active .clsPrimaryGrammarTabButtonGreen5 {
    background-color: #00CE4E; /* Selected Color */
    color: white; 
}
.clsPrimaryGrammarTabButton5.active .clsPrimaryGrammarTabButtonGreen5::after {
     border-top-color: #00CE4E; /* Match Selected Color */
}

/* Style for the inner GRAY div when its parent button is ACTIVE */
.clsPrimaryGrammarTabButton5.active .clsPrimaryGrammarTabButtonGray5 {
    background-color: #00CE4E; /* Change to Selected Color */
    color: white;
}
.clsPrimaryGrammarTabButton5.active .clsPrimaryGrammarTabButtonGray5::after {
     border-top-color: #00CE4E; /* Match Selected Color */
}

/* Ensure NO hover effects change layout or active color */
.clsPrimaryGrammarTabButton5:hover {
    /* No transform, no shadow */
    /* Optional: Slightly change background on hover without affecting active state */
    /* Example: filter: brightness(95%); */ 
}

.clsPrimaryGrammarTabContents5 {
    background-color: white;
    /*border-radius: 20px;*/
    padding: 40px 30px;
    text-align: center;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.05);
    position: relative;
    z-index: 0;
    margin-top: 10px; /* Add space below the fins */
    width: 100%; 
    box-sizing: border-box; 
}

/* --- NEW Styles for Video in Tabs --- */
.tab-video-container-2col {
    display: flex;
    justify-content: space-around; /* Or space-between */
    align-items: flex-start;
    flex-wrap: wrap;
    gap: 20px; /* Adjust gap as needed */
    padding: 20px 0; /* Add some padding */
}

/* Add styles for the new tab video titles */
.clsPrimaryGrammarTabVideoTitle {
    font-size: 1em; /* Kept user's size */
    font-weight: 500; /* Kept user's weight */
    color: #E4FFEF; /* Reverted to dark color for visibility */
    text-align: center;
    margin-bottom: 5px; /* Kept space */
    line-height: 1.1; /* Reduced line-height for less vertical space */
}

/* Ensure video wrappers in tabs behave correctly */
.clsPrimaryGrammarTabContent5 .clsPrimaryGrammarVideoWrapper3 {
    flex: 1 1 45%; /* Allow wrapping for 2 columns, adjust % based on gap */
    max-width: 400px; /* Max width for each video */
    /* Inherit styles from section 3? Check if needed */
}

/* Responsive styles for tab videos */
@media screen and (max-width: 768px) {
    .tab-video-container-2col {
        flex-direction: column;
        align-items: center;
    }
    .clsPrimaryGrammarTabContent5 .clsPrimaryGrammarVideoWrapper3 {
        flex-basis: 80%; /* Take more width when stacked */
        max-width: 450px; /* Adjust max-width */
    }
}

/* --- End NEW Styles for Video in Tabs --- */