.site-header {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 99;
    padding: 15px 0;
    transition: all 0.3s ease;
}


.site-header.fixed-header {
    position: fixed;
    background: #fff;
    box-shadow: 0 0 15px rgba(0,0,0,0.1);
    padding: 10px 0;
    animation: slideDown 0.5s forwards;
}

/* bodypadding-top， */
body.has-fixed-header {
    padding-top: 60px; 
}

@keyframes slideDown {
    from {
        transform: translateY(-100%);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.header-box {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.site-branding {
    max-width: 160px;
}

.toggle-button {
    display: none;
}

.main-navigation .menu {
    margin: 0;
    padding: 0;
    list-style: none;
    display: flex;
}

.main-navigation .menu > li {
    margin: 0 5px;
    position: relative;
}

.main-navigation .menu > li > a {
    display: block;
    padding: 15px 18px;
    color: #333;
    font-weight: 500;
    position: relative;
    transition: all 0.3s ease;
}

.main-navigation .menu > li > a:after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    width: 0;
    height: 2px;
    background: #1f6bdb;
    transition: all 0.3s ease;
    transform: translateX(-50%);
}

.main-navigation .menu > li > a:hover:after,
.main-navigation .menu > li.active > a:after {
    width: 40px;
}

.sub-menu {
    position: absolute;
    top: 100%;
    left: 0;
    width: 220px;
    background: #fff;
    border-radius: 10px;
    padding: 10px 0;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
    transition: all 0.3s ease;
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    z-index: 999;
}

.sub-items:hover .sub-menu {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.sub-menu li {
    list-style: none;
}

.sub-menu li a {
    display: block;
    padding: 8px 18px;
    color: #333;
    transition: all 0.3s ease;
}

.sub-menu li a:hover {
    color: #1f6bdb;
    background: #f5f5f5;
}

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

.sec-btn-menu {
    padding: 10px 20px;
    margin-left: 10px;
}

.btn-sign-in {
    background: transparent;
    color: #333;
    border: 1px solid #ddd;
}

.btn-sign-in:hover {
    background: #f5f5f5;
    color: #1f6bdb;
}


@media (max-width: 991px) {
    .site-header.fixed-header {
        background: rgba(255, 255, 255, 0.7);
    }
    .header-box {
        position: relative;
        display: flex;
        align-items: center;
        justify-content: space-between;
        padding: 5px 0;
    }
    
    .site-branding {
        max-width: 120px;
    }
    
    /* header-menu */
    .header-menu {
        transition: all 0.3s ease;
    }
    
    .main-navigation {
        position: fixed;
        top: 0;
        right: -300px;
        width: 300px;
        height: 100vh;
        background: #fff;
        z-index: 999;
        overflow-y: auto;
        transition: all 0.3s ease;
        padding: 20px 15px 100px 15px;
        box-shadow: -5px 0 15px rgba(0, 0, 0, 0.1);
        -webkit-overflow-scrolling: touch;
        display: block;
    }
    
    .main-navigation.active {
        right: 0;
        opacity: 1;
        visibility: visible;
    }
    
    .black-shadow {
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
        background: rgba(0,0,0,0.7);
        z-index: 998;
        opacity: 0;
        visibility: hidden;
        transition: all 0.3s ease;
    }
    
    .black-shadow.active {
        opacity: 1;
        visibility: visible;
    }
    
    .toggle-button {
        display: block !important;
        position: absolute;
        right: 15px;
        top: 50%;
        transform: translateY(-50%);
        width: 30px;
        height: 25px;
        background: transparent;
        border: none;
        cursor: pointer;
        z-index: 1000;
        padding: 0;
        margin: 0;
    }
    
    .toggle-button span {
        display: block;
        position: absolute;
        height: 3px;
        width: 100%;
        background: #1f6bdb;
        border-radius: 3px;
        opacity: 1;
        left: 0;
        transform: rotate(0deg);
        transition: .25s ease-in-out;
    }
    
    .toggle-button span:nth-child(1) {
        top: 0px;
    }
    
    .toggle-button span:nth-child(2) {
        top: 10px;
    }
    
    .toggle-button span:nth-child(3) {
        top: 20px;
    }
    
    .toggle-button.active span:nth-child(1) {
        top: 10px;
        transform: rotate(135deg);
    }
    
    .toggle-button.active span:nth-child(2) {
        opacity: 0;
        left: -60px;
    }
    
    .toggle-button.active span:nth-child(3) {
        top: 10px;
        transform: rotate(-135deg);
    }
    
    .menu {
        margin: 0;
        padding: 15px 0 100px 0;
        list-style: none;
        display: flex;
        flex-direction: column;
    }
    
    .menu > li {
        display: block;
        margin: 0;
        border-bottom: 1px solid #f0f0f0;
    }
    
    .menu > li > a {
        padding: 12px 15px;
        display: block;
        color: #333;
        font-weight: 500;
    }
    
    .menu > li:hover {
        background: #f8f8f8;
    }
    
    .sub-menu {
        position: static;
        width: 100%;
        box-shadow: none;
        opacity: 1;
        visibility: visible;
        transform: none;
        padding-left: 15px;
        background: #f8f8f8;
        display: none;
        border-radius: 0;
    }
    
    .sub-menu li a {
        padding: 10px 15px;
    }
    
    .sub-items.active .sub-menu {
        display: block;
    }
    
    body.menu-open {
        position: fixed;
        width: 100%;
        height: 100%;
        overflow: hidden;
    }
}

/* iOS */
.ios-device.menu-open {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    overflow: hidden;
    height: 100%;
}

.ios-device .main-navigation.active {
    padding-bottom: 150px; /* iOS */
    right: 0 !important;
    display: block !important;
    visibility: visible !important;
    opacity: 1 !important;
}