*{
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
a{
    text-decoration: none;
}
.top-nav{
    background-color: #2196F3;
}
.nav-wrap{
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 16px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}
.nav-left{
    display:flex;
}
.nav-left a{
    color:#fff;
    font-size:18px;
    margin-right:24px;
}
.nav-search {
    display:flex;
    flex:1;
    max-width:600px;
}
.nav-search input[name="keyword"] {
    flex:1;
    padding:8px 14px;
    border:none;
    border-radius:22px 0 0 22px;
    outline:none;
    font-size:15px;
}
.nav-search button {
    padding:0 16px;
    border:none;
    background:#1976D2;
    color:#fff;
    border-radius:0 22px 22px 0;
    cursor:pointer;
    font-size:14px;
}
.nav-search button:hover{
    background:#1565C0;
}
.nav-right{
    display:flex;
}
.nav-right a{
    color:#fff;
    font-size:18px;
    margin-left:16px;
    margin-right:0;
}
.footer{
    text-align:center;
    padding:30px 0;
    margin-top:30px;
}

/* 手机端 ≤700px，竖向排列，全部居中 */
@media (max-width:700px) {
    .nav-wrap{
        height:auto;
        flex-direction:column;
        padding:12px 16px;
        gap:12px;
    }
    .nav-left{
        width:100%;
        display:flex;
        justify-content:center;
    }
    .nav-search{
        width:100%;
        max-width:100%;
    }
    .nav-right{
        width:100%;
        display:flex;
        justify-content:center;
    }
    .nav-left a,.nav-right a{
        font-size:16px;
        margin:0 12px;
    }
}