/* Header Styles */
.site-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(6, 18, 45, 0.95);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    transition: all var(--transition-normal);
}

.site-header::before {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, rgba(59, 130, 246, 0.5) 50%, transparent);
}

.header-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: var(--space-lg) var(--space-xl);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

/* Logo */
.header-logo {
    flex-shrink: 0;
}

.logo-link {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    text-decoration: none;
    transition: all var(--transition-normal);
}

.logo-link:hover .logo-icon {
    filter: drop-shadow(0 0 15px rgba(59, 130, 246, 0.8));
    transform: scale(1.05);
}

.logo-link:hover .logo-text {
    color: var(--color-primary);
}

.logo-icon {
    width: 40px;
    height: 40px;
    color: var(--color-primary);
    filter: drop-shadow(0 0 10px rgba(59, 130, 246, 0.5));
    transition: all var(--transition-normal);
}

.logo-text {
    font-family: var(--font-primary);
    font-size: 1.5rem;
    font-weight: var(--font-weight-bold);
    color: var(--color-text-primary);
    letter-spacing: 0.1em;
    transition: all var(--transition-normal);
}

/* Navigation */
.header-nav {
    flex-grow: 1;
    display: flex;
    justify-content: center;
}

.nav-list {
    display: flex;
    list-style: none;
    padding: 0;
    margin: 0;
    gap: var(--space-3xl);
    align-items: center;
}

.nav-item {
    position: relative;
    padding-bottom: 20px;
    margin-bottom: -20px;
}

.nav-link {
    position: relative;
    color: var(--color-text-secondary);
    text-decoration: none;
    font-family: var(--font-secondary);
    font-size: 1rem;
    font-weight: var(--font-weight-medium);
    padding: var(--space-sm) var(--space-md);
    transition: all var(--transition-normal);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    display: flex;
    align-items: center;
    gap: var(--space-xs);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 0;
    height: 2px;
    background: linear-gradient(90deg, var(--color-primary), var(--color-secondary));
    transition: width var(--transition-normal);
}

.nav-link:hover,
.nav-link.active {
    color: var(--color-primary);
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}

/* Dropdown Arrow */
.nav-arrow {
    width: 10px;
    height: 10px;
    transition: transform var(--transition-normal);
}

.nav-item:hover .nav-arrow {
    transform: rotate(180deg);
}

/* Dropdown Menu */
.nav-dropdown {
    position: absolute;
    top: 100%;
    left: 50%;
    transform: translateX(-50%);
    width: max-content;
    max-width: min(760px, calc(100vw - 2rem));
    background: rgba(6, 18, 45, 0.98);
    backdrop-filter: blur(20px);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-lg);
    padding: var(--space-md);
    padding-top: calc(var(--space-md) + 10px);
    display: grid;
    grid-template-columns: repeat(3, minmax(190px, 1fr));
    gap: 0.25rem 0.5rem;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.2s ease, visibility 0.2s ease;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.3);
    z-index: 100;
}

/* Invisible bridge to prevent gap */
.nav-dropdown::before {
    content: '';
    position: absolute;
    top: -20px;
    left: 0;
    right: 0;
    height: 20px;
    background: transparent;
}

/* Arrow indicator */
.nav-dropdown::after {
    content: '';
    position: absolute;
    top: 2px;
    left: 50%;
    transform: translateX(-50%);
    border-left: 8px solid transparent;
    border-right: 8px solid transparent;
    border-bottom: 8px solid rgba(255, 255, 255, 0.1);
}

.nav-item:hover .nav-dropdown {
    opacity: 1;
    visibility: visible;
}

.dropdown-link {
    display: block;
    padding: 0.65rem 0.85rem;
    color: var(--color-text-secondary);
    text-decoration: none;
    font-family: var(--font-secondary);
    font-size: 0.92rem;
    font-weight: var(--font-weight-medium);
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
    white-space: nowrap;
}

.dropdown-link:hover {
    color: var(--color-primary);
    background: rgba(59, 130, 246, 0.12);
    transform: translateX(2px);
}

.dropdown-link.active {
    color: var(--color-primary);
    background: rgba(59, 130, 246, 0.15);
}

/* Mobile Menu Toggle */
.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    gap: 6px;
    background: transparent;
    border: none;
    cursor: pointer;
    padding: var(--space-sm);
}

.mobile-menu-toggle span {
    display: block;
    width: 25px;
    height: 2px;
    background: var(--color-text-primary);
    transition: all var(--transition-normal);
}

.mobile-menu-toggle:hover span {
    background: var(--color-primary);
}

/* Scrolled State */
.site-header.scrolled {
    background: rgba(6, 18, 45, 0.98);
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.3);
}

/* Mobile Responsive */
@media (max-width: 768px) {
    .header-container {
        padding: var(--space-md) var(--space-lg);
    }

    .logo-icon {
        width: 35px;
        height: 35px;
    }

    .logo-text {
        font-size: 1.2rem;
    }

    .header-nav {
        position: fixed;
        top: 70px;
        left: 0;
        right: 0;
        background: rgba(6, 18, 45, 0.98);
        backdrop-filter: blur(20px);
        border-bottom: 1px solid rgba(255, 255, 255, 0.1);
        padding: var(--space-xl) 0;
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: all var(--transition-normal);
    }

    .header-nav.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }

    .nav-list {
        flex-direction: column;
        gap: var(--space-sm);
        padding: 0 var(--space-lg);
    }

    .nav-item {
        width: 100%;
    }

    .nav-link {
        display: flex;
        justify-content: space-between;
        padding: var(--space-md) var(--space-lg);
        border-radius: var(--radius-lg);
        background: rgba(255, 255, 255, 0.03);
    }

    .nav-link::after {
        display: none;
    }

    .nav-link:hover,
    .nav-link.active {
        background: rgba(59, 130, 246, 0.1);
    }

    /* Mobile Dropdown — single column, scrollable */
    .nav-dropdown {
        position: static;
        transform: none;
        width: 100%;
        max-width: 100%;
        display: block;
        opacity: 1;
        visibility: visible;
        background: transparent;
        border: none;
        border-radius: 0;
        padding: 0;
        box-shadow: none;
        max-height: 0;
        overflow: hidden;
        transition: max-height var(--transition-normal);
    }

    .nav-dropdown::before,
    .nav-dropdown::after {
        display: none;
    }

    .nav-item.open .nav-dropdown {
        max-height: 70vh;
        overflow-y: auto;
        transform: none;
        padding: var(--space-xs) 0;
    }

    .dropdown-link {
        padding: var(--space-md) var(--space-lg) var(--space-md) var(--space-3xl);
        font-size: 0.9rem;
        border-radius: 0;
    }

    .dropdown-link:hover {
        transform: none;
    }

    .mobile-menu-toggle {
        display: flex;
        z-index: 1001;
    }

    .mobile-menu-toggle.active span:nth-child(1) {
        transform: rotate(45deg) translate(8px, 8px);
    }

    .mobile-menu-toggle.active span:nth-child(2) {
        opacity: 0;
    }

    .mobile-menu-toggle.active span:nth-child(3) {
        transform: rotate(-45deg) translate(7px, -7px);
    }
}

@media (max-width: 480px) {
    .logo-text {
        font-size: 1rem;
    }

    .logo-icon {
        width: 30px;
        height: 30px;
    }
}

/* Adjust main content for fixed header */
body {
    padding-top: 80px;
}

@media (max-width: 768px) {
    body {
        padding-top: 70px;
    }
}