/*  --------------- 스타일 초기화 --------------- */
    /* 세로 스크롤 숨기기, 스크롤 가능 */
    html, body {
        overflow-y: scroll; /* 실제 스크롤은 가능 */
        scrollbar-width: none; /* Firefox */
        -ms-overflow-style: none; /* IE, Edge */
    }
    /* Chrome, Safari, Opera */
    html::-webkit-scrollbar, 
    body::-webkit-scrollbar {
        display: none;
    }


body,html {
    overflow-x: hidden;
}
body {
    background: #111113;
    color: #fff;
    user-select: none;
}
header {
    width: 100%;
    background: transparent;
    position: fixed;
    z-index: 99;
    display: flex;
    justify-content: end;
    align-items: center;
    padding: 20px 100px;
}
header a.back-bt {
    position: relative;
    display: block;
    width: 60px;
    height: 60px;
    border-radius: 50px;
    cursor: pointer;

    background: transparent;
    --line-color: #fff;
    transition: 0.3s ease;
}

/* X (두 개의 선) */
header a.back-bt::before,
header a.back-bt::after {
    content: "";
    position: absolute;
    left: 50%;
    top: 50%;
    width: 30px;
    height: 2px;
    background: var(--line-color);

    transform-origin: center;
    transform: translate(-50%, -50%) rotate(45deg);
    transition: 0.3s ease;
}

/* 두 번째 선 */
header a.back-bt::after {
    transform: translate(-50%, -50%) rotate(-45deg);
}

/* 🔥 호버 시: X에만 빛이 들어옴 */
header a.back-bt:hover::before,
header a.back-bt:hover::after {
    background: lime;
    box-shadow: 0 0 6px lime, 0 0 12px lime, 0 0 18px lime;
}
div.down {
    position: absolute;
    top: 40%;
    left: 50%;
    transform: translateX(-50%);
    z-index: 10;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}
div.down h2 {
    font-size: 20px;
    letter-spacing: 5px;
}
.down .arrow {
    stroke: #00ff80;                /* 기본 네온 그린 */
    stroke-width: 3;
    stroke-linecap: round;
    stroke-linejoin: round;
    fill: none;
    transition: 0.25s ease;
    stroke: #00ff80;
    filter: drop-shadow(0 0 6px #00ff80);
    margin-top: 10px;
    /* 🔥 아래→위로 무한 반복 애니메이션 */
    animation: arrowBounce 1.2s ease-in-out infinite;
}
/* 🔥 화살표 이동 keyframes */
@keyframes arrowBounce {
    0% {
        transform: translateY(0);
        opacity: 1;
    }
    50% {
        transform: translateY(8px); /* 아래로 이동 */
        opacity: 0.6;              /* 살짝 흐려짐 */
    }
    100% {
        transform: translateY(0);
        opacity: 1;
    }
}








.page-drop-blur {
    animation: pageDropBlur 0.7s ease forwards;
}

@keyframes pageDropBlur {
    0% {
        opacity: 1;
        transform: translateY(0);
        filter: blur(0px);
    }
    100% {
        opacity: 0;
        transform: translateY(120px);
        filter: blur(12px);
    }
}
/* --------------------------- section ----------------------- */
section.history {
    width: 100%;
    height: 830px;
    background: url('images/history_bg.png') no-repeat center / cover;
    z-index: 2;
}
section.timeline-area {
    width: 100%;
    background: #111113; /* 배경색 */
}
.article {
    padding-top: 100px;
}
.article a.logo {
    display: block;
    height: 75px;
    background: url('images/logos/Kgfc_logo_upscaling_white.png') no-repeat center / cover;
    background-size: contain;
}
.article h1.title {
    font-weight: 100;
    font-size: 80px;
    text-align: center;
    margin: 30px 0 50px;
}
.article div.icon {
    width: 100px;
    height: 100px;
    background: url('images/icons/스크롤아이콘.png') no-repeat center;
    margin: 0 auto;
    
}
div.main-line {
    position: relative;
    width: 2px;
    height: 3200px;
    margin: 0 auto;
    border-radius: 100px;
    /* 세로 방향 3단 그라데이션 */
    background: linear-gradient(to bottom,#101213,#35403A,#101213);
    display: flex;
    justify-content: center;
}

/* ----------- circle --------- */
div.circle {
    width: 20px;
    height: 20px;
    background-color: #2FFF97; /* 녹색 */
    border-radius: 50%; /* 완전한 원 */
    position: absolute;
    top: 0;
    z-index: 2;
    
    /* 네온 아웃글로우 효과 */
    box-shadow:
        0 0 5px #2FFF97,
        0 0 10px #2FFF97,
        0 0 15px #2FFF97,
        0 0 20px #2FFF97;
    /* 펄스 효과 애니메이션 */
    animation: neonPulse 1.2s ease-in-out infinite;
}
/* 펄스 조명 애니메이션 */
@keyframes neonPulse {
    0%, 100% {
        transform: scale(1);
        box-shadow:
            0 0 5px #2fff47,
            0 0 10px #2fff47,
            0 0 15px #2fff47,
            0 0 20px #2fff47;
    }
    50% {
        transform: scale(1.2);
        box-shadow:
            0 0 10px #2fff47,
            0 0 20px #2fff47,
            0 0 30px #2fff47,
            0 0 40px #2fff47;
    }
}

/* s--------------------------------------------- */
.timeline-area {
    position: relative;
}

.history-item.left {
    position: absolute;
    top: 200px;      /* main-line 기준 */
    right: 60%;      /* main-line 왼쪽에 배치 */
    text-align: right;
}

.history-item.right {
    position: absolute;
    top: 400px;
    left: 60%;       /* main-line 오른쪽에 배치 */
    text-align: left;
}
.history-item h3 {
    font-size: 40px;
    font-weight: 800;
    margin-bottom: 10px;
}
.history-item p {
    font-size: 25px;
    font-weight: 200;
    line-height: 150%;
}

/* -------------- 좌측 텍스트 y값 조절 ---------------- */
.history-item.left:nth-child(2) { top: 500px; }
.history-item.left:nth-child(3) { top: 800px; }
.history-item.left:nth-child(4) { top: 1200px; }
.history-item.left:nth-child(5) { top: 1800px; }
.history-item.left:nth-child(6) { top: 2400px; }

/* -------------- 우측 텍스트 y값 조절 ---------------- */
.history-item.right:nth-child(8) { top: 780px; }
.history-item.right:nth-child(9) { top: 1600px; }
.history-item.right:nth-child(10) { top: 2000px; }
.history-item.right:nth-child(11) { top: 2700px; }


/* ------------- 하단 로고 ----------------- */
a.bt-logo {
    display: block;
    width: 237px;
    height: 68px;
    margin:  100px auto 50px;
    background: url('images/logos/kgfc로고-국문포함.png') no-repeat center / cover;
    background-size: contain;
    z-index: 2;
}

/* -------------------------- 배경 레이어 --------------------- */
.rising-light-bg {
    position: fixed;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none; /* 클릭 방해 안 함 */
    overflow: hidden;
    z-index: 0; /* 콘텐츠보다 뒤쪽 */
    background: transparent;
}

/* ----------------- 빛줄기 -------------------- */
.rising-light-bg::before,
.rising-light-bg::after {
    content: "";
    position: absolute;
    bottom: -100px; /* 화면 아래에서 시작 */
    width: 2px;     /* 빛줄기 너비 */
    height: 150px;  /* 빛줄기 길이 */
    background: linear-gradient(to top, rgba(47,255,151,0.8), transparent);
    animation: rise 3s linear infinite;
}
/* 위치를 랜덤하게 여러 개 만들려면 각각 left 값 다르게 */
.rising-light-bg::before { left: 20%; animation-delay: 0s; }
.rising-light-bg::after  { left: 60%; animation-delay: 1.5s; }
/* 애니메이션 정의 */
@keyframes rise {
    0% {
        transform: translateY(-120vh) scaleY(1);
        opacity: 0.1;
    }
    50% {
        opacity: 1;
    }
    100% {
        transform: translateY(100vh) scaleY(1.5); /* 화면 위로 이동 */
        opacity: 0.1;
    }
    
}

/* -------------공통 펄스조명--------------- */
/* 펄스조명 스타일 */
/* 랜덤 펄스용 네온 조명 */
.pulse-light {
    position: absolute;
    width: 120px;                     /* 기본 크기 */
    height: 120px;
    background: rgba(0, 255, 100, 0.6);
    border-radius: 50%;
    filter: blur(60px);
    pointer-events: none;
    z-index: 1;
    animation: glowPulse 2.5s infinite alternate;  /* 기존 애니메이션 */
}

@keyframes glowPulse {
    0% {
        transform: scale(1);
        opacity: 0.4;
    }
    100% {
        transform: scale(1.2);
        opacity: 0.6;
    }
}

/* 텍스트 사이 가로선 */
.timeline-line {
    position: absolute;
    height: 2px;
    background-color: #2FFF97; /* 네온 녹색 */
    width: 0;                  /* 초기 0 */
    top: 50%;                  /* 텍스트 세로 중앙 */
    pointer-events: none;
    transition: width 0.5s ease-out;
}


.to-top-btn {
    position: fixed;
    bottom: 20px;
    right: 50px;
    padding: 12px 14px;
    background: none;
    color: #fff;
    border-radius: 50px;
    border: 2px solid #fff;
    cursor: pointer;
    font-size: 14px;
    z-index: 999;
    opacity: 0;               /* 기본은 숨김 */
    transition: opacity 0.4s; /* 부드러운 페이드 */
    pointer-events: none;      /* 숨김 상태에서 클릭 불가 */
    transition: 300ms;
    }

    .to-top-btn.show {
    opacity: 1;
    pointer-events: auto;
    }

    .to-top-btn:hover {
    border-color: lime;
    box-shadow: 0 0 6px lime, 0 0 12px lime, 0 0 20px lime;
    transition: 0.5s;
    color: lime;
    }