:root {
    
    --nav-bg: var(--color-primary-dark);
    --nav-text: var(--color-white);
    --nav-hover-bg: #555555;
    --nav-hover-text: var(--color-accent);
    
    
    --dropdown-bg: #444444;
    --dropdown-text: #d3f31b;
    --dropdown-hover-bg: #666666;
    
    
    --header-padding: 1rem;
    --nav-item-padding: 0.2rem 1.5rem;
    --dropdown-padding: 1rem 2rem;
    
    
    --transition-fast: 0.2s ease-in-out;
    --transition-medium: 0.3s ease-in-out;
    
    
    --z-skip-link: 9999;
    --z-header: 1000;
    --z-dropdown: 1001;
    --z-mobile-menu: 1002;
}






.skip-link {
    position: absolute;
    top: -100px;
    left: 0;
    background-color: var(--color-accent);
    color: var(--color-primary-dark);
    padding: 1rem 2rem;
    text-decoration: none;
    font-weight: bold;
    z-index: var(--z-skip-link);
    border-radius: 0 0 0.5rem 0;
    transition: top var(--transition-fast);
}

.skip-link:focus {
    top: 0;
    outline: 3px solid var(--color-primary-dark);
    outline-offset: 3px;
}




.site-header {
    background-color: var(--nav-bg);
    position: sticky;
    top: 0;
    z-index: var(--z-header);
    width: 100%;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    
    
    -webkit-transform: translateZ(0);
    transform: translateZ(0);
    will-change: transform;
}




.header-info {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin: 0 auto;
    padding: 0.5rem var(--header-padding);
    background-color: var(--nav-bg);
    color: var(--nav-text);
    min-height: 2.5rem;
}


.logo-container {
    display: flex;
    align-items: center;
    padding-left: 2rem;
}

.logo-link {
    display: block;
    line-height: 0;
}

.logo-link:focus {
    outline: 3px solid var(--color-accent);
    outline-offset: 5px;
    border-radius: 0.25rem;
}

.logo {
    height: 2.5rem;
    width: auto;
    display: block;
    transition: transform var(--transition-medium);
}

.logo-link:hover .logo,
.logo-link:focus .logo {
    transform: scale(1.05);
}


.site-title {
    flex: 1;
    text-align: center;
    padding: 0 1rem;
}

.site-title-text {
    font-size: clamp(1rem, 3vw, 1.5rem);
    margin: 0;
    color: var(--nav-text);
    font-weight: bold;
}




.mobile-menu-toggle {
    display: none; 
    background: transparent;
    border: 2px solid var(--nav-text);
    color: var(--nav-text);
    padding: 0.5rem;
    cursor: pointer;
    border-radius: 0.25rem;
    transition: all var(--transition-fast);
    min-width: 44px;  
    min-height: 44px;
}

.mobile-menu-toggle:hover,
.mobile-menu-toggle:focus {
    background-color: rgba(255, 255, 255, 0.1);
    border-color: var(--color-accent);
    outline: none;
}

.mobile-menu-toggle:focus-visible {
    outline: 3px solid var(--color-accent);
    outline-offset: 2px;
}


.menu-icon {
    display: flex;
    flex-direction: column;
    gap: 4px;
    width: 24px;
}

.menu-line {
    display: block;
    width: 100%;
    height: 3px;
    background-color: var(--nav-text);
    transition: transform var(--transition-fast), opacity var(--transition-fast);
}


.mobile-menu-toggle[aria-expanded="true"] .menu-line:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
}

.mobile-menu-toggle[aria-expanded="true"] .menu-line:nth-child(2) {
    opacity: 0;
}

.mobile-menu-toggle[aria-expanded="true"] .menu-line:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
}

.menu-text {
    display: block;
    font-size: 0.75rem;
    margin-top: 0.25rem;
    font-weight: bold;
}




.main-navigation {
    background-color: var(--nav-bg);
    margin-bottom: 1rem ;
}

.nav-list {
    display: flex;
    justify-content: center;
    align-items: center;
    flex-wrap: wrap;
    list-style: none;
    margin: 0;
    padding: 0;
    max-width: 1600px;
    margin: 0 auto;
}

.nav-item {
    position: relative;
    margin: 0;
}


.nav-link {
    display: block;
    padding: var(--nav-item-padding);
    color: var(--nav-text);
    text-decoration: none;
    font-weight: bold;
    font-size: clamp(0.875rem, 1.5vw, 1.125rem);
    transition: all var(--transition-medium);
    border-radius: 0.25rem;
    position: relative;
}


.nav-link:hover,
.nav-link:focus {
    background-color: var(--nav-hover-bg);
    color: var(--nav-hover-text);
    transform: translateY(-2px);
}

.nav-link:focus-visible {
    outline: 3px solid var(--color-accent);
    outline-offset: 2px;
}


.nav-link[aria-current="page"] {
    background-color: rgba(255, 255, 255, 0.15);
    color: var(--color-accent);
    font-weight: bold;
}




.submenu {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    background-color: var(--dropdown-bg);
    list-style: none;
    margin: 0;
    padding: 0.5rem 0;
    min-width: 220px;
    border-radius: 0.5rem;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
    z-index: var(--z-dropdown);
    opacity: 0;
    transform: translateY(-10px);
    transition: opacity var(--transition-fast), transform var(--transition-fast);
}


.nav-item:hover .submenu,
.nav-item:focus-within .submenu,
.has-submenu .nav-link[aria-expanded="true"] + .submenu {
    display: block;
    opacity: 1;
    transform: translateY(0);
}

.submenu-item {
    margin: 0;
}

.submenu-link {
    display: block;
    padding: var(--dropdown-padding);
    color: var(--dropdown-text);
    text-decoration: none;
    transition: background-color var(--transition-fast), padding-left var(--transition-fast);
    font-size: 0.95rem;
}

.submenu-link:hover,
.submenu-link:focus {
    background-color: var(--dropdown-hover-bg);
    padding-left: 2.5rem;
}

.submenu-link:focus-visible {
    outline: 2px solid var(--color-accent);
    outline-offset: -2px;
}




main[role="main"] {
    outline: none; 
}




@media screen and (max-width: 1024px) and (min-width: 841px) {
    .nav-link {
        padding: 0.875rem 1rem;
        font-size: 1rem;
    }
    
    .site-title-text {
        font-size: 1.25rem;
    }
}




@media screen and (max-width: 840px) {
    
    
    .mobile-menu-toggle {
        display: flex;
        flex-direction: column;
        align-items: center;
        justify-content: center;
    }
    
    
    .header-info {
        padding: 0.75rem 1rem;
        gap: 1rem;
    }
    
    .logo {
        height: 2rem;
    }
    
    .site-title {
        flex: 1;
        text-align: left;
        padding: 0 0.5rem;
    }
    
    .site-title-text {
        font-size: 1rem;
    }
    
    
    .main-navigation {
        display: none; 
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background-color: var(--nav-bg);
        border-top: 2px solid rgba(255, 255, 255, 0.2);
        box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
        z-index: var(--z-mobile-menu);
        max-height: calc(100vh - 5rem);
        overflow-y: auto;
    }
    
    
    .mobile-menu-toggle[aria-expanded="true"] ~ .main-navigation {
        display: block;
    }
    
    
    .nav-list {
        flex-direction: column;
        align-items: stretch;
        padding: 0.5rem 0;
    }
    
    .nav-item {
        border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    }
    
    .nav-item:last-child {
        border-bottom: none;
    }
    
    
    .nav-link {
        padding: 1rem 1.5rem;
        font-size: 1.125rem;
        border-radius: 0;
    }
    
    .nav-link:hover,
    .nav-link:focus {
        transform: none;
        background-color: rgba(255, 255, 255, 0.1);
    }
    
    
    .submenu {
        position: static;
        display: none;
        width: 100%;
        box-shadow: none;
        border-radius: 0;
        background-color: rgba(0, 0, 0, 0.2);
        padding: 0;
        transform: none;
        opacity: 1;
    }
    
    
    .has-submenu .nav-link[aria-expanded="true"] + .submenu {
        display: block;
    }
    
    .submenu-link {
        padding: 0.875rem 2.5rem;
        font-size: 1rem;
        color: var(--color-text-light);
    }
    
    .submenu-link:hover,
    .submenu-link:focus {
        background-color: rgba(255, 255, 255, 0.15);
        padding-left: 3rem;
    }
    
}




@media screen and (max-width: 480px) {
    .header-info {
        padding: 0.5rem;
    }
    
    .logo {
        height: 1.75rem;
    }
    
    .site-title-text {
        font-size: 0.875rem;
    }
    
    .mobile-menu-toggle {
        min-width: 40px;
        min-height: 40px;
        padding: 0.375rem;
    }
    
    .menu-icon {
        width: 20px;
    }
    
    .menu-text {
        font-size: 0.65rem;
    }
    
    .nav-link {
        padding: 0.875rem 1rem;
        font-size: 1rem;
    }
    
    .submenu-link {
        padding: 0.75rem 2rem;
        font-size: 0.9rem;
    }
}




@media print {
    .skip-link,
    .mobile-menu-toggle {
        display: none;
    }
    
    .site-header {
        position: static;
        box-shadow: none;
    }
    
    .nav-list {
        display: none;
    }
}




@media (prefers-contrast: high) {
    .nav-link:focus,
    .submenu-link:focus {
        outline-width: 4px;
    }
    
    .mobile-menu-toggle {
        border-width: 3px;
    }
}




@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
    
    .nav-link:hover,
    .nav-link:focus {
        transform: none;
    }
    
    .submenu {
        transform: none;
    }
}