:root {
    --primary: #1E3A8A;
    --secondary: #374151;
    --accent: #0284E7;
    --background: #F3F4F6;
    --warning: #EF4444;
    --warning-active: #DC2626;
}

html {
    scroll-behavior: smooth;
    font-family: "LXGW WenKai TC", cursive;
    background-color: var(--background);
}

img {
    object-fit: cover;
}

.flex {
    display: flex;
    align-items: center;
}

.hover, .hover::after, .hover::before {
    transition: 400ms;
}

.title {
    font-size: 2rem;
    font-weight: 700;
}

.subttl {
    font-size: 1.3rem;
    font-weight: 700;
}

.content {
    letter-spacing: 0.04rem;
    line-height: 28px;
}

.ctt-em {
    padding: 0 0.5rem;
    font-size: 1.1rem;
}



header {
    width: 100%;
    height: 120px;

    justify-content: space-around;

    color: #fff;

    position: fixed;
    top: 0;

    z-index: 3;
}

header.active {
    height: 80px;
    background-color: #fff;
    color: var(--secondary);
    box-shadow: 0 5px 20px hsla(0, 0%, 0%, 0.05);
}

nav {
    gap: 20px;

    font-size: 1.2rem;
    font-weight: 700;
}

    nav .nav-item {
        position: relative;
    }

    nav .nav-item::after {
        content: "";
        width: 0;
        height: 2px;
        background-color: #fff;

        position: absolute;
        top: 100%;
        left: 0;
    }

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

    header.active .nav-item::after {
        background-color: var(--secondary);
    }

footer {
    padding: 70px 120px 80px;

    flex-direction: column;
    gap: 50px;

    color: #fff;
    background-color: var(--primary);
}

    footer > .flex {
        flex-direction: column;
        gap: 20px;
    }

        footer .flex .flex {
            gap: 20px;
        }

#warning {
    width: 100%;
    padding: 30px 240px 40px 120px;

    background-color: #fff;

    position: fixed;
    bottom: 0;
}

    #warning-ttl {
        padding-bottom: 20px;
    }

        #warning .warning-wrap {
            padding-bottom: 10px;
        }   

    #warning-confirm {
        width: 120px;
        height: 60px;

        justify-content: center;

        color: #fff;
        background-color: var(--warning);

        position: absolute;
        top: calc(50% - 20px);
        right: 120px;

        cursor: pointer;
    }

    #warning-confirm:hover {
        background-color: var(--warning-active);
    }