.site-header {
    background: linear-gradient(135deg, #15607A 0%, #0B4B61 100%);
    color: white;
    padding: 0;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    position: relative;
    z-index: 1000;
}

.header-container {
    /* max-width: 1400px; */
    width: 100%;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
}

.header-top {
    padding: 0.5rem 20px;
    text-align: center;
}

.header-logo {
    text-decoration: none;
    color: white;
    text-align: center;
    margin-bottom: 0.25rem;
}

.header-logo h1 {
    font-size: 1.75rem;
    margin: 0;
    font-weight: 600;
    color: white;
}

.header-subtitle {
    font-size: 1.2rem;
    opacity: 0.8;
    margin-top: 0.15rem;
    color: white;
}

.social-links {
    display: flex;
    justify-content: center;
    gap: 0.5rem;
    margin-top: 0.5rem;
}

.social-icon {
    width: 20px;
    height: 20px;
    opacity: 0.8;
    transition: opacity 0.2s ease;
    cursor: pointer;
}

.social-icon:hover {
    opacity: 1;
}

.twitter-dropdown,
.bluesky-dropdown {
    position: relative;
}

.twitter-menu,
.bluesky-menu {
    display: none;
    position: absolute;
    top: 100%;
    left: 50%;
    transform: translateX(-50%);
    background-color: #FFFFFF;
    padding: 0.5rem;
    border-radius: 4px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.2);
    margin-top: 0.5rem;
    z-index: 1002;
    min-width: 180px;
    white-space: nowrap;
}

.twitter-menu.active,
.bluesky-menu.active {
    display: block;
}

.twitter-menu::before,
.bluesky-menu::before {
    content: '';
    position: absolute;
    top: -6px;
    left: 50%;
    transform: translateX(-50%);
    border-left: 6px solid transparent;
    border-right: 6px solid transparent;
    border-bottom: 6px solid #FFFFFF;
}

.twitter-menu a,
.bluesky-menu a {
    color: #15607A;
    text-decoration: none;
    padding: 0.5rem;
    display: block;
    text-align: center;
    transition: background-color 0.2s ease;
    border-radius: 2px;
    background-color: #FFFFFF;
}

.twitter-menu a:hover,
.bluesky-menu a:hover {
    background-color: #F5F5F5;
}

.header-nav {
    display: flex;
    justify-content: center;
    align-items: stretch;
    background-color: rgba(255,255,255,0.05);
    width: 100%;
}

.header-nav > a,
.header-nav > .nav-item > a {
    color: white;
    text-decoration: none;
    font-size: 1rem;
    font-weight: 500;
    padding: 1rem;
    transition: background-color 0.2s ease;
    display: flex;
    align-items: center;
}

.header-nav a:hover {
    background-color: rgba(255,255,255,0.1);
}

.header-nav a.active {
    background-color: rgba(255,255,255,0.2);
}

.nav-item {
    position: relative;
    display: flex;
    align-items: stretch;
}

.nav-item > a::after {
    content: '▼';
    font-size: 0.7em;
    margin-left: 0.5rem;
    opacity: 0.8;
}

.submenu {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    background: #15607A;
    min-width: 200px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.2);
    z-index: 1001;
}

.nav-item:hover > .submenu {
    display: block;
}

.submenu a {
    color: white;
    text-decoration: none;
    padding: 0.75rem 1rem;
    display: block;
    transition: background-color 0.2s ease;
    white-space: nowrap;
}

.submenu a:hover {
    background-color: rgba(255,255,255,0.1);
}

@media (max-width: 768px) {
    .header-container {
        padding: 1rem;
    }
    
    .header-top {
        padding: 0;
    }

    .header-nav {
        flex-wrap: wrap;
        background-color: transparent;
        gap: 0.5rem;
        justify-content: center;
    }

    .header-nav > a,
    .header-nav > .nav-item > a {
        padding: 0.5rem 1rem;
        border-radius: 4px;
    }

    .nav-item {
        position: relative;
        width: 100%;
    }

    .nav-item > a {
        justify-content: center;
    }

    .nav-item > a::after {
        display: inline;
        margin-left: 0.5rem;
    }

    .submenu {
        display: none;
        position: static;
        width: 100%;
        margin-top: 0.25rem;
        border-radius: 4px;
        background-color: rgba(255,255,255,0.05);
        box-shadow: none;
    }

    .submenu.active {
        display: block;
    }

    .submenu a {
        padding: 0.5rem 1rem;
        text-align: center;
    }
}