* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Microsoft YaHei' sans-serif;
}

:root{
    --main-bg-color:black;
    --color-primary:#5683c3;
    --color-button:#b1d1ee;

}
::selection {
    color: #000;
    background-color: #fff;

}

nav {
    position: fixed;
    background-color:var(--main-bg-color);
    width: 100%;
    padding: 8px 0;
    z-index: 10;
}

nav .menu {
    max-width: 1250px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 20px;
    margin: auto;
}

nav .menu .logo p {
    color: #fff;
    font-size: 2rem;
    font-weight: 600;
}

.menu ul {
    display: inline-flex;
}

.menu ul li {
    list-style: none;
    margin-left: 7px;
}

.menu ul li:first-child {
    margin-left: 0;
}

.menu ul li a {
    text-decoration: none;
    color: #fff;
    font-size: 1.1rem;
    font-weight: 500;
    padding: 8px 15px;
    border-radius: 5px;
    transition: all 0.3 ease;
}

.menu ul li a:hover {
    background-color: #fff;
    color: #000;
}

.image {
    background: url(./image/bgc2.jpg) no-repeat;
    width: 100%;
    height: 100vh;
    background-size: cover;
    background-position: center;
    position: relative;
}

.image::before {
    content: "";
    position: absolute;
    width: 100%;
    height: 100%;
    background: rgba(63, 79, 101, 0.3);
}

.center {
    position: absolute;
    top: 52%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 100%;
    padding: 0 20px;
    text-align: center;
}

.center .title {
    color: #fff;
    font-size: 3rem;
    font-weight: 600;
}

.center .sub-title {
    color: #fff;
    font-size: 2rem;
    font-weight: 600;
}

.center .btns {
    margin-top: 20px;
}

.center .btns a {
    height: 55px;
    width: 170px;
    border-radius: 5px;
    margin: 0 10px;
    border: 2px solid white;
    font-size: 1.5rem;
    font-weight: 500;
    padding: 5px 10px;
    cursor: pointer;
    transition: all 0.3 ease;
    text-decoration: none;
}

.center .btns a:first-child {
    color: #fff;
    background: none;
}

.center .btns a:first-child:hover {
    background: white;
    color: #000;
}

.center .btns a:last-child {
    color: #fff;
    background: none;
}

.center .btns a:last-child:hover {
    background: white;
    color: #000;
}


@media only screen and (max-width: 600px) {
    nav .menu {
    flex-direction: column;
    align-items: flex-start;
    }
    
    nav .menu .logo p {
    font-size: 1.5rem;
    }
    
    .menu ul {
    margin-top: 10px;
    }
    
    .menu ul li {
    margin-left: 0;
    margin-bottom: 5px;
    }
    
    .center .title {
    font-size: 2.5rem;
    }
    
    .center .sub-title {
    font-size: 1.5rem;
    }
    
    .center .btns a {
    height: 45px;
    width: 140px;
    font-size: 1.2rem;
    padding: 5px;
    }
    }