@keyframes mainFade {
    0% {
        opacity: 0;
        transform: translate(-50%, -60%) scale(0.95);
    }
    100% {
        opacity: 1;
        transform: translate(-50%, -50%) scale(1);
    }
}

#bg-video {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    z-index: -2;
}

.video-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(
            to bottom,
            rgba(0, 0, 0, 0.0) 0%,
            rgba(0, 0, 0, 0.15) 30%,
            rgba(0, 0, 0, 0.25) 60%,
            rgba(0, 0, 0, 0.45) 100%
    );
    pointer-events: none;
    z-index: -1;
}

/* 메인 타이틀 (교통 이상 징후 감지 시스템) */
.main-title {
    font-size: 42px;
    font-weight: 300;
    color: white;
    text-shadow: 0 8px 20px rgba(0, 0, 0, 0.6);
    animation: fadeUp 1.5s ease-out;
    font-family: 'Pretendard', sans-serif;
    white-space: nowrap;
}

/* 서브 타이틀 (WatchTower-AI)*/
.sub-title {
    font-size: 80px;
    font-weight: 600;
    color: white;
    opacity: 0;
    animation: fadeIn 1.5s ease-out forwards;
    animation-delay: 1.2s;
    text-shadow: 0 6px 15px rgba(0, 0, 0, 0.5);
    font-family: 'Pretendard', sans-serif;
    white-space: nowrap;


}

.sub-title::after {
    content: "";
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 0;
    height: 3px;
    background: rgba(255, 255, 255, 0.9);
    animation: underlineGrow 1.2s ease-out forwards;
    animation-delay: 1.4s;
}

@keyframes underlineGrow {
    0% {
        width: 0;
        opacity: 0;
    }
    100% {
        width: 550px;
        opacity: 1;
    }
}

.content-wrapper {
    padding-top: 80px;
    padding-bottom: 20px;
    width: 100%;
}

.navbar-blur {
    background: linear-gradient(
            to bottom,
            rgba(0, 0, 0, 0.55),
            rgba(0, 0, 0, 0.20)
    ) !important;
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.4);
    min-height: auto !important;
}

/* 메뉴 글자 */
.navbar-blur .nav-link,
.navbar-blur .navbar-brand {
    color: white !important;
    font-family: "Pretendard", sans-serif;
    font-weight: 300;
}


.navbar-nav .nav-link {
    position: relative;
    color: white !important;
    white-space: nowrap;
    padding-bottom: 4px;
    transition: color 0.3s ease;
}

.navbar-nav .nav-link::after {
    content: "";
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background-color: #ffffff;
    transition: width 0.3s ease;
}

.navbar-nav .nav-link:hover::after {
    width: 100%;
}

.navbar-nav .nav-link.active {
    color: #fff !important;
}

.navbar-nav .nav-link.active::after {
    width: 100%;
    background-color: #fff;
}


.navbar-brand img {
    margin-right: 6px;
}

.brand-thin {
    font-weight: 100;
    letter-spacing: 0.5px;
}


.hamburger-btn {
    background: transparent;
    border: none;
    padding: 6px;
    filter: none;
}

.navbar-right.dropdown:hover .dropdown-menu {
    display: block;
}

.dropdown-menu {
    background-color: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(4px);
    animation: dropdownFade 0.25s ease;
    border: none;
}

@keyframes dropdownFade {
    from {
        opacity: 0;
        transform: translateY(-5px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.dropdown-item {
    color: #fff;
}

.dropdown-item:hover {
    background-color: rgba(255, 255, 255, 0.15);
}

.dropdown-menu-end {
    right: 0 !important;
    left: auto !important;
}


/* 메뉴 짤리지 않도록 */
.navbar-nav .nav-link {
    white-space: nowrap !important;
}


.navbar-collapse {
    flex-basis: 100% !important;
}


@media (max-width: 992px) {
    .navbar-nav {
        width: 100% !important;
        flex-wrap: wrap !important;
        justify-content: center !important;
    }

    .navbar-brand {
        margin-bottom: 6px;
    }
}

.navbar-nav.mx-auto {
    transform: none !important;
}

/* 창이 작아졌을때 뜨는 햄버거 */
.navbar-toggler-icon {
    background-image: url("data:image/svg+xml;charset=utf8,%3Csvg viewBox='0 0 30 30' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath stroke='%23ffffff' stroke-width='2' stroke-linecap='round' stroke-miterlimit='10' d='M4 7h22M4 15h22M4 23h22'/%3E%3C/svg%3E") !important;
}

.navbar-toggler:focus,
.navbar-toggler:focus-visible {
    box-shadow: 0 0 0 2px #ffffff;
    outline: none;
}