:root {
    --color-black: #101010;
    --color-white: #ffffff;

    --color-background: #F5FAFF;

    --color-highlight: #1C60FC;
    --color-highlight-sub: #27BDE1;
    
    --font-title-1: 64px;
    --font-title-2: 56px;
    --font-title-3: 40px;

    --font-xl: 28px;
    --font-l: 24px;
    --font-m: 20px;
    --font-s: 18px;
    --font-xs: 16px;

    --size-xl: 160px;
    --size-l: 120px;
    --size-m: 80px;
    --size-s: 40px;
    --size-xs: 20px;
}

/* ---------------- COMMON ---------------- */


.pc-hidden{
    display: none;
}

.mo-hidden{
    display: initial;
}

::selection {
    background-color: var(--color-black);
    color: var(--color-highlight-sub);
}

* {
    margin: 0;
    padding: 0;
    list-style: none;
    text-decoration: none;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    min-width: 360px;
    max-width: 100vw;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: flex-start;
    align-items: center;
    background-color: var(--color-white);
}

section{
    width: 100%;
    display: flex;
    flex-direction: column;
    justify-content: flex-start;
    align-items: center;
    padding-top: var(--size-xl);
    padding-bottom: var(--size-xl);
}

.section-wrapper{
    max-width: 1440px;
    width: 100%;
    height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: flex-start;
    align-items: center;
    padding-left: 20px;
    padding-right: 20px;
}

.section-tag{
    display: inline-block;
    font-family: 'Pretendard Variable', sans-serif;
    font-size: var(--font-m);
    font-weight: 700;
    color: var(--color-highlight);
    background-color: #E8F0FF;
    border-radius: 4px;
    padding: 8px 20px;
}

.section-title{
    font-family: 'Pretendard Variable', sans-serif;
    font-size: var(--font-title-3);
    font-weight: 600;
    color: var(--color-black);
    word-break: keep-all;
    line-height: 135%;
    margin-top: var(--size-xs);
    margin-bottom: var(--size-s);
}

.section-desc{
    font-family: 'Pretendard Variable', sans-serif;
    font-size: var(--font-l);
    font-weight: 300;
    color: var(--color-black);
    word-break: keep-all;
    line-height: 150%;
}

/* ---------------- HEADER ---------------- */

header{
    min-width: 360px;
    position: fixed;
    width: 100%;
    height: var(--size-m);
    min-height: 64px;
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 10;
}

header.sticky{
    background-color: var(--color-black);
}

.header-wrapper{
    max-width: 1440px;
    width: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-left: 20px;
    padding-right: 20px;
}

.logo{
    display: flex;
    justify-content: center;
    align-items: center;
}

.logo > img{
    width: 180px;
    object-fit: contain;
}

.header-wrapper > nav > ul{
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    column-gap: var(--size-s);
}

.header-wrapper > nav > ul > li > a{
    font-family: 'Pretendard Variable', sans-serif;
    font-size: var(--font-xs);
    font-weight: 300;
    color: var(--color-white);
    padding: 12px 0;
    transition: 0.2s;
}

.header-wrapper > nav > ul > li > a:hover{
    text-decoration: underline;
    text-underline-offset: 12px;
    text-decoration-thickness: 1px;
}

/* ---------------- HOME ---------------- */

#home{
    position: relative;
    min-height: 100vh;
    justify-content: center;
    padding-top: calc(64px + var(--size-xl));
}

.bg-overlay{
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    width: 100%;
    height: 100%;
    min-height: 100vh;
    background: linear-gradient(180deg, #10101080, #10101000);
    z-index: 2;
    line-height: 0;
}

.bg-video{
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    width: 100%;
    height: 100%;
    min-height: 100vh;
    object-fit: cover;
    z-index: 1;
    line-height: 0;
}

#home > .section-wrapper{
    justify-content: center;
    align-items: flex-start;
    z-index: 5;
}

.title-top{
    display: flex;
    justify-content: flex-start;
    align-items: center;
}

.title-top > img{
    width: var(--size-m);
    object-fit: contain;
}

.title-top > p{
    font-family: 'Pretendard Variable', sans-serif;
    font-size: var(--font-title-2);
    font-weight: 300;
    color: var(--color-white);
    margin-left: var(--size-xs);
}

.title{
    font-family: 'Pretendard Variable', sans-serif;
    font-size: var(--font-title-1);
    font-weight: 700;
    color: var(--color-white);
    line-height: 135%;
    word-break: keep-all;
    margin-top: 12px;
}

.title-bottom{
    width: 100%;
    display: grid;
    grid-template-columns: 1fr 1fr;
    column-gap: var(--size-s);
    margin-top: var(--size-s);
}

.title-bottom > div{
    width: 100%;
    margin-top: var(--size-s);
}

.title-bottom > div > a{
    display: inline-block;
}

.title-bottom > div > a:hover > div{
    background: transparent;
    background-color: var(--color-highlight);
}

.title-bottom > div > a > div{
    width: 320px;
    display: flex;
    justify-content: center;
    align-items: center;
    background-color: var(--color-highlight-sub);
    padding: 16px;
    border-radius: 4px;
    transition: 0.2s;
}

.title-bottom > div > a > div > img{
    width: var(--font-m);
    object-fit: contain;
    margin-right: var(--size-xs);
}

.title-bottom > div > a > div > p{
    font-family: 'Poppins', sans-serif;
    font-size: var(--font-m);
    font-weight: 500;
    color: var(--color-white);
}

.title-bottom > div > p{
    font-family: 'Pretendard Variable', sans-serif;
    font-size: var(--font-xs);
    font-weight: 300;
    color: var(--color-white);
    line-height: 135%;
    margin-top: var(--size-xs);
    letter-spacing: -0.1px;
}

.title-bottom > img{
    width: 100%;
    object-fit: contain;
    border-radius: var(--size-xs);
    border: 1px solid #505050;
    margin-top: var(--size-xs);
}

/* ---------------- FEATURES ---------------- */

#features{
    background-color: var(--color-background);
}

.abstract-tag{
    font-family: 'Poppins', sans-serif;
    font-size: var(--font-l);
    font-weight: 500;
    color: var(--color-highlight);
    margin-bottom: 8px;
}


.abstract-title{
    font-family: 'Pretendard Variable', sans-serif;
    font-size: var(--font-title-2);
    font-weight: 700;
    color: var(--color-black);
}

#features > .section-wrapper > div{
    width: 100%;
    display: grid;
    grid-template-columns: 1fr 1fr 1fr 1fr;
    margin-top: var(--size-m);
}

#features > .section-wrapper > div > div{
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: 8px 0;
    border-right: 1px solid #1010101A;
}

#features > .section-wrapper > div > div:last-of-type{
    border: none;
}

#features > .section-wrapper > div > div > p:nth-of-type(1){
    font-family: 'Pretendard Variable', sans-serif;
    font-size: var(--font-xl);
    font-weight: 500;
    color: var(--color-black);
}

#features > .section-wrapper > div > div > p:nth-of-type(2){
    font-family: 'Pretendard Variable', sans-serif;
    font-size: var(--font-s);
    font-weight: 300;
    color: var(--color-black);
    word-break: keep-all;
    line-height: 150%;
    margin-top: 12px;
}

#feature-1, #feature-3{
    background-color: var(--color-white);
}

/**
#feature-1 > .section-wrapper, #feature-3 > .section-wrapper{
    width: 100%;
    display: grid;
    flex-direction: initial;
    justify-content: initial;
    align-items: initial;
    grid-template-columns: 1fr 3fr;
    column-gap: calc(var(--size-xl) * 1.5);
}
*/
#feature-2, #feature-4{
    background-color: var(--color-background);
}
/**
#feature-2 > .section-wrapper, #feature-4 > .section-wrapper{
    width: 100%;
    display: grid;
    flex-direction: initial;
    justify-content: initial;
    align-items: initial;
    grid-template-columns: 3fr 1fr;
    column-gap: calc(var(--size-xl) * 1.5);
}
*/

.feature > .section-wrapper{
    flex-direction: row;
    justify-content: space-between;
    align-items: center;
}

#feature-1 > .section-wrapper > div, #feature-3 > .section-wrapper > div{
    padding-left: var(--size-xl);
}

#feature-2 > .section-wrapper > div, #feature-4 > .section-wrapper > div{
    padding-right: var(--size-xl);
}

.feature > .section-wrapper img{
    width: 320px;
    height: 320px;
    object-fit: contain;
}

/* ---------------- GUIDE ---------------- */

#guide{
    background-color: var(--color-white);
}

.guide-contents{
    width: 100%;
    display: grid;
    grid-template-columns: 1fr 1fr;
    column-gap: var(--size-s);
    margin-top: var(--size-m);
}

.guide-content{
    width: 100%;
    display: flex;
    flex-direction: column;
    justify-content: flex-start;
    align-items: center;
}

.guide-content > img{
    width: 100%;
    object-fit: contain;
    border-radius: var(--size-xs);
}

.guide-content > div{
    width: 100%;
    padding: 0 var(--size-xs);
    margin-top: var(--size-s);
}

/* ---------------- Download ---------------- */

#download{
    background-color: var(--color-background);
}

.download-content{
    width: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--size-m);
    background-color: var(--color-white);
    border: 1px solid var(--color-highlight);
    border-radius: var(--size-xs);
    margin-top: var(--size-m);
}

.download-content > img{
    max-width: 280px;
    width: 100%;
    object-fit: contain;
}

.download-content > div{
    max-width: 768px;
    margin-right: var(--size-m);
}

.download-content > div > h3{
    font-family: 'Poppins', sans-serif;
    font-size: var(--font-title-3);
    font-weight: 500;
    color: var(--color-black);
}

.download-content > div > h4{
    font-family: 'Pretendard Variable', sans-serif;
    font-size: var(--font-l);
    font-weight: 500;
    color: var(--color-highlight);
    word-break: keep-all;
    margin-top: var(--size-xs);
    margin-bottom: var(--size-xs);
}

.download-content > div > a{
    display: inline-block;
    margin-top: var(--size-m);
}

.download-content > div > a:hover > div{
    background: transparent;
    background-color: var(--color-highlight-sub);
}

.download-content > div > a > div{
    width: 320px;
    display: flex;
    justify-content: center;
    align-items: center;
    background-color: var(--color-highlight);
    padding: 16px;
    border-radius: 4px;
    transition: 0.2s;
}

.download-content > div > a > div > img{
    width: var(--font-m);
    object-fit: contain;
    margin-right: var(--size-xs);
}

.download-content > div > a > div > p{
    font-family: 'Pretendard Variable', sans-serif;
    font-size: var(--font-m);
    font-weight: 500;
    color: var(--color-white);
}

.download-content > div > p:nth-of-type(2){
    max-width: 320px;
    width: 100%;
    text-align: center;
    font-family: 'Pretendard Variable', sans-serif;
    font-size: var(--font-s);
    font-weight: 300;
    color: var(--color-black);
    margin-top: 12px;
}

/* ---------------- FOOTER ---------------- */

footer{
    width: 100%;
    background-color: var(--color-highlight);
    padding: var(--size-s) 0;
    display: flex;
    justify-content: center;
    align-items: center;
}

.footer-wrapper{
    max-width: 1440px;
    width: 100%;
    padding: 0 var(--size-xs);
}

.footer-wrapper > p{
    width: 100%;
    text-align: right;
}

.footer-wrapper > p, .footer-wrapper > div:nth-of-type(1) > p{
    font-family: 'Pretendard Variable', sans-serif;
    font-size: var(--font-xs);
    font-weight: 300;
    color: var(--color-white);
    line-height: 135%;
    word-break: keep-all;
}

.footer-wrapper > div:nth-of-type(1){
    margin-top: 12px;
    margin-bottom: 12px;
}

.footer-wrapper > div:nth-of-type(1) > p:nth-of-type(1){
    margin-bottom: 12px;
    font-weight: 700;
}

.footer-wrapper > div:nth-of-type(2){
    width: 100%;
    display: flex;
    justify-content: flex-end;
    align-items: center;
}

.footer-wrapper > div:nth-of-type(2) > a{
    font-family: 'Pretendard Variable', sans-serif;
    font-size: var(--font-xs);
    font-weight: 700;
    color: var(--color-white);
    line-height: 135%;
}

.footer-wrapper > div:nth-of-type(2) > a:nth-of-type(2){
    margin-left: var(--size-s);
}

.footer-wrapper a{
    color: var(--color-white);
}


@media screen and (max-width: 1200px) {
    :root {
        --font-title-1: 56px;
        --font-title-2: 48px;
        --font-title-3: 32px;
    
        --font-xl: 24px;
        --font-l: 22px;
        --font-m: 18px;
        --font-s: 17px;
        --font-xs: 15px;
    
        --size-xl: 108px;
        --size-l: 90px;
        --size-m: 72px;
        --size-s: 36px;
        --size-xs: 18px;
    }

    .logo > img{
        width: 144px;
        object-fit: contain;
    }
    

    .title-bottom{
        grid-template-columns: 3fr 4fr;
    }
    
    #features > .section-wrapper > div{
        display: grid;
        grid-template-columns: 1fr 1fr;
        row-gap: var(--size-s);
    }

    #features > .section-wrapper > div > div:nth-of-type(2){
        border: none;
    }

    #feature-1 > .section-wrapper > div, #feature-3 > .section-wrapper > div{
        padding-left: var(--size-l);
    }
    
    #feature-2 > .section-wrapper > div, #feature-4 > .section-wrapper > div{
        padding-right: var(--size-l);
    }


    /**

    #feature-1 > .section-wrapper, #feature-3 > .section-wrapper{
        column-gap: var(--size-l);
    }

    #feature-2 > .section-wrapper, #feature-4 > .section-wrapper{
        column-gap: var(--size-l);
    }
        */


    .feature > .section-wrapper  img{
        width: 280px;
        height: 280px;
        object-fit: contain;
    }

    .download-content > img{
        max-width: 220px;
        width: 100%;
        object-fit: contain;
    }
}

@media screen and (max-width: 1080px) {
    .title-bottom{
        grid-template-columns: 1fr;
        row-gap: var(--size-xs);
        margin-top: 0;
    }

    .title-bottom > img{
        max-width: 640px;
    }

    .feature > .section-wrapper img{
        width: 200px;
        height: 200px;
        object-fit: contain;
    }
}

@media screen and (max-width: 768px) {
    :root {
        --font-title-1: 48px;
        --font-title-2: 40px;
        --font-title-3: 28px;
    
        --font-xl: 22px;
        --font-l: 20px;
        --font-m: 18px;
        --font-s: 16px;
        --font-xs: 14px;
    
        --size-xl: 96px;
        --size-l: 80px;
        --size-m: 64px;
        --size-s: 32px;
        --size-xs: 16px;
    }

    .section-desc{
        font-size: var(--font-m);
    }


    .logo > img{
        width: 132px;
        object-fit: contain;
    }

    .header-wrapper > nav > ul{
        display: flex;
        justify-content: flex-end;
        column-gap: 0px;
        align-items: center;
    }

    .header-wrapper > nav > ul >li:not(.header-wrapper > nav > ul > li:last-of-type){
        margin-right: 12px;
    }

    .mo-hidden{
        display: none;
    }

    .pc-hidden{
        display: initial;
    }

    #features > .section-wrapper > div{
        grid-template-columns: 1fr;
        row-gap: var(--size-xs);
    }

    #features > .section-wrapper > div > div{
        border-right: 0;
        border-bottom : 1px solid #1010101A !important;
        padding-top: 0;
        padding-bottom: var(--size-xs);
    }

    #features > .section-wrapper > div > div:last-of-type{
        border-bottom: none !important;
        padding-bottom: 0;
    }



/**
    #feature-1 > .section-wrapper, #feature-3 > .section-wrapper{
        display: grid;
        grid-template-columns: 1fr;
        row-gap: var(--size-s);
    }
    
    #feature-2 > .section-wrapper, #feature-4 > .section-wrapper{
        display: grid;
        grid-template-columns: 1fr;
        row-gap: var(--size-s);
    }
*/

.feature > .section-wrapper{
    flex-direction: column;
    justify-content: flex-start;
    align-items: flex-start;
}

.feature >.section-wrapper > div{
    padding: 0 !important;
    margin-top: var(--size-s);
}

    .feature > .section-wrapper  img{
        width: 120px;
        height: 120px;
        object-fit: contain;
    }

    .guide-contents{
        grid-template-columns: 1fr;
        row-gap: var(--size-m);
    }

    .guide-content > div{
        padding: 0 0;
    }
    
    .download-content{
        flex-direction: column;
        align-items: flex-start;
        padding: var(--size-m) var(--size-s);
    }

    .download-content > img{
        max-width: 120px;
    }

    .download-content > div{
        margin-right: 0;
        margin-top: var(--size-s);
    }

    .download-content > div > a{
        margin-top: var(--size-s);
    }

    .title-bottom > div > a > div{
        width: 260px;
    }

    .download-content > div > a > div{
        width: 260px;
    }

    .download-content > div > p:nth-of-type(2){
        max-width: 260px;
    }

    .download-content > img{
        width: 80px;
    }
}