:root {
    --color: #eeb111;
    --color-w: #fff;
    --color-b: #000;
    --color-z: #555555;


    /* 文字大小 */

    --font: 12px;
}

* {
    padding: 0;
    margin: 0;
    box-sizing: border-box;
    font-family: var(--font-fam);
}

html,
body {
    height: 100%;
}

body {
    display: flex;
    flex-direction: column;
}

main {
    flex: 1;
}

header {
    height: 80px;
    background-color: var(--color-w);
    position: sticky;
    z-index: 10;
}

nav {
    max-width: 1440px;
    margin: 0 auto;
}

li {
    list-style: none;
}

a {
    text-decoration: none;
    color: white;
}

.nav-bar {
    min-height: 80px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 24px;
    z-index: 100;
}

.nav-menu {
    margin-left: auto;
    margin-right: 50px;
    display: flex;
    gap: 20px;

}

.nav-branding {
    font-size: 2rem;
    z-index: 100;
}
.nav-branding img{
    max-height: 50px !important;
    width: auto;
}
.nav-link {
    transition: 0.7S;
    color: var(--color-z);
    font-size: 17px;
    font-family: 'Raleway, sans-serif';
    height: 80px;
    line-height: 80px;
    position: relative;
}

.nav-link:hover::after {
    content: '';
    position: absolute;
    top: 47px;
    left: 0;
    width: 100%;
    height: 3px;
    background-color: var(--color);
    transition: all 0.3S ease-in-out;
}
.hamburger{
    display: flex;
    justify-content: ;
}
/* .nav-link:hover {
    color: red;
} */

.hamburger {
    display: none;
    /* 鼠标悬浮在该元素上时，光标变成小手样式 */
    cursor: pointer;
}

.bar {
    display: block;
    background-color: #333;
    width: 25px;
    height: 3px;
    margin: 5px;
    transition: all 0.3S ease-in-out;
}

@media screen and (max-width:768px) {
    header {
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        height: 80px !important;
        z-index: 999 !important;
    }

    main {
        padding-top: 80px;
    }

    .nav-bar {
        position: relative;
        z-index: 100 !important;
    }

    .hamburger {
        width: 44px;
        height: 44px;
        color: var(--color-b);
        display: block;
        touch-action: manipulation;
        z-index: 1001 !important;
        padding-left: 10px;
    }

    .hamburger.active .bar:nth-child(2) {
        opacity: 0
    }

    .hamburger.active .bar:nth-child(1) {
        transform: translateY(8px) rotate(45deg);
    }

    .hamburger.active .bar:nth-child(3) {
        transform: translateY(-8px) rotate(-45deg);
    }

    .nav-menu {
        padding-top: 20px;
        flex-direction: column;
        align-items: flex-start;
        gap: 0;
        margin: 0;
        position: fixed;
        top: 80px;
        right: 0;
        bottom: 0;
        background: rgba(0, 0, 0, 0.85);
        width: 0;
        overflow: hidden;
        overflow-y: auto;
        white-space: nowrap;
        opacity: 0;
        transition: all 0.3s;
    }

    .nav-link {
        color: var(--color-w);
        height: 40px;
        line-height: 50px;
    }

    .nav-item {
        height: 50px;
        line-height: 50px;
        margin-left: 30px;
    }

    .nav-menu.active {
        width: 100%;
        opacity: 1;
    }

    .nav-branding img {
        height: 40px;
        width: auto;
        margin-bottom: 10px;
    }
    .nav-bar {
    padding: 0 10px;
}
}