header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 50;
    transition: all 0.3s ease;
    padding: 16px 0;
}

header.scrolled {
    background-color: #ffffff;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

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

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

.logo img {
    height: 40px;
    margin-right: 12px;
}

.logo span {
    color: #fff;
    font-size: 20px;
    font-weight: bold;
    transition: color 0.3s ease;
}
header.scrolled .logo span {
    color: #1f2937;
}

.menu-toggle {
    display: none;
    cursor: pointer;
    flex-direction: column;
    justify-content: space-between;
    width: 28px;
    height: 24px;
}

.menu-toggle span {
    display: block;
    height: 2px;
    width: 100%;
    background-color: #1D2129;
    border-radius: 2px;
    transition: background-color 0.3s ease;
}

header.scrolled .menu-toggle span {
    background-color: #1f2937;
}

nav {
    transition: max-height 0.3s ease;
}

nav ul {
    display: flex;
    list-style: none;
    gap: 32px;
}

nav ul li a {
    text-decoration: none;
    transition: color 0.3s;
    color: var(--text-1, #1D2129);
    /* 16/CN-Regular */
    font-family: "PingFang SC";
    font-size: 16px;
    font-style: normal;
    font-weight: 400;
    line-height: 24px; /* 150% */
}

header.scrolled nav ul li a {
    color: #1f2937;
}

nav ul li a:hover {
    color: #60a5fa;
}

header.scrolled nav ul li a:hover {
    color: #2563eb;
}
.demo-btn-menu{
   border-bottom: 2px solid #1D2129;
}
.demo-btn {
    background-color: #2563eb;
    color: #fff !important;
    padding: 5px 16px;
    border-radius: 16px;
    text-decoration: none;
    font-size: 14px;
    transition: all 0.3s;
    display: flex;
    align-items: center;
    margin-top: -5px;
    cursor: pointer;
}

.demo-btn:hover {
    background-color: #1d4ed8;
}

header.scrolled .demo-btn {
    background-color: #2563eb;
    color: #fff;
}

.mobile-nav {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background-color: #ffffff;
    box-shadow: 0 10px 15px rgba(0, 0, 0, 0.1);
    max-height: 0;
    overflow: hidden;
    transition: all 0.3s ease;
}

header.scrolled .mobile-nav {
    background-color: #ffffff;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    border-top: 1px solid rgba(0, 0, 0, 0.1);
}

.mobile-nav ul {
    flex-direction: column;
    align-items: center;
    padding: 16px 0;
    gap: 16px;
}

header.scrolled .mobile-nav ul li a {
    color: #1f2937;
}

header.scrolled .mobile-nav ul li a:hover {
    color: #2563eb;
}

@media (max-width: 767px) {
    .menu-toggle {
        display: flex;
    }
    
    nav:not(.mobile-nav) {
        display: none;
    }
    
    .mobile-nav {
        display: block;
    }
    .mobile-nav ul li a {
        color: #1f2937;
    }

    .mobile-nav ul li .demo-btn {
        color: #fff;
    }
}

@media (max-width: 480px) {
    .header-content {
        padding: 12px 0;
    }
    
    .logo img {
        height: 32px;
        margin-right: 8px;
    }
    
    .logo span {
        font-size: 16px;
    }
}