/* =============================================
   SITE CHROME — Navigation, Skip Link, Back-to-Top
   Extracted from base.html for maintainability.
   All values use design tokens from main.css.
   ============================================= */

/* ─────────────────────────────────────────────
   Top Navigation
   ───────────────────────────────────────────── */

.nav-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 var(--space-8);
    height: 60px;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: var(--space-1);
}

.nav-link {
    padding: var(--space-2) var(--space-3);
    font-size: var(--text-xs-plus);
    font-weight: var(--font-medium);
    color: var(--color-text-secondary);
    text-decoration: none;
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
}

.nav-link:hover {
    color: var(--color-text);
    background: var(--color-bg-muted);
}

.nav-link-featured,
.nav-link-quiz {
    color: var(--color-primary);
    font-weight: var(--font-semibold);
}

.nav-link-featured:hover,
.nav-link-quiz:hover {
    background: var(--color-primary-50);
    color: var(--color-primary-dark);
}

/* Login link surfaced in header (auth-state link) */
.nav-link-login {
    font-weight: var(--font-semibold);
}

/* Dropdown */

.nav-dropdown {
    position: relative;
}

.nav-dropdown-trigger {
    display: inline-flex;
    align-items: center;
    gap: var(--space-1);
    padding: var(--space-2) var(--space-3);
    font-size: var(--text-sm);
    font-weight: var(--font-medium);
    color: var(--color-text-secondary);
    background: none;
    border: none;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.nav-dropdown-trigger:hover {
    color: var(--color-text);
    background: var(--color-bg-muted);
}

.nav-chevron {
    width: 14px;
    height: 14px;
    transition: transform var(--transition-fast);
}

.nav-dropdown:hover .nav-chevron {
    transform: rotate(180deg);
}

.nav-dropdown-menu {
    position: absolute;
    top: 100%;
    left: 0;
    transform: translateY(8px);
    min-width: 200px;
    background: var(--color-bg);
    border: none;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    padding: var(--space-2);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-base);
    z-index: 1000;
}

.nav-dropdown:hover .nav-dropdown-menu,
.nav-dropdown:focus-within .nav-dropdown-menu {
    opacity: 1;
    visibility: visible;
    transform: translateY(4px);
}

.nav-dropdown-link-simple {
    display: block;
    padding: var(--space-2) var(--space-3);
    font-size: var(--text-xs-plus);
    font-weight: var(--font-medium);
    color: var(--color-text-secondary);
    text-decoration: none;
    border-radius: var(--radius-xs);
    transition: background var(--transition-fast);
}

.nav-dropdown-link-simple:hover {
    background: var(--color-bg-muted);
    color: var(--color-text);
}

.nav-dropdown-link-featured {
    color: var(--color-primary);
    font-weight: var(--font-semibold);
}

.nav-dropdown-link-featured:hover {
    background: var(--color-primary-50);
    color: var(--color-primary-dark);
}

.nav-dropdown-divider {
    height: 1px;
    background: var(--color-border);
    margin: var(--space-1) 0;
}

.nav-dropdown-menu-wide {
    min-width: 220px;
}

.nav-dropdown-section {
    padding: var(--space-1) 0;
}

.nav-dropdown-label {
    display: block;
    padding: var(--space-1) var(--space-3);
    font-size: var(--text-xs);
    font-weight: var(--font-semibold);
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

/* Primary CTA in nav (gradient + lift) */

.nav-cta {
    display: inline-flex;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-2-5) var(--space-5);
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-light) 100%);
    color: var(--color-text-inverse);
    font-size: var(--text-xs-plus);
    font-weight: var(--font-semibold);
    text-decoration: none;
    border-radius: var(--radius-lg);
    margin-left: var(--space-4);
    transition: all var(--transition-base);
    box-shadow: var(--shadow-primary);
    position: relative;
    overflow: hidden;
}

.nav-cta::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, var(--color-primary-light) 0%, var(--color-primary) 100%);
    opacity: 0;
    transition: opacity var(--transition-fast);
}

.nav-cta span,
.nav-cta svg {
    position: relative;
    z-index: 1;
}

.nav-cta svg {
    transition: transform var(--transition-fast);
}

.nav-cta:hover {
    color: var(--color-text-inverse);
    box-shadow: var(--shadow-primary-lg);
    transform: translateY(-1px);
}

.nav-cta:hover::before {
    opacity: 1;
}

.nav-cta:hover svg {
    transform: translateX(3px);
}

.nav-cta:active {
    transform: translateY(0);
    box-shadow: var(--shadow-sm);
}

/* Mobile menu toggle */

.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    width: 40px;
    height: 40px;
    padding: 0;
    background: none;
    border: none;
    cursor: pointer;
    gap: 5px;
}

.mobile-menu-toggle span {
    display: block;
    width: 20px;
    height: 2px;
    background: var(--color-text-secondary);
    transition: all var(--transition-fast);
}

@media (max-width: 900px) {
    .nav-links {
        display: none;
        position: fixed;
        top: 60px;
        left: 0;
        right: 0;
        bottom: 0;
        background: var(--color-bg);
        flex-direction: column;
        align-items: stretch;
        padding: var(--space-2);
        gap: 0;
        overflow-y: auto;
        z-index: 999;
        border-top: 1px solid var(--color-border);
    }

    .nav-links.active {
        display: flex;
    }

    .mobile-menu-toggle {
        display: flex;
    }

    .mobile-menu-toggle.active span:nth-child(1) {
        transform: translateY(7px) rotate(45deg);
    }

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

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

    .nav-link {
        padding: var(--space-3) var(--space-4);
        font-size: var(--text-base);
        border-bottom: 1px solid var(--color-bg-muted);
        border-radius: 0;
    }

    .nav-dropdown {
        width: 100%;
    }

    .nav-dropdown-trigger {
        width: 100%;
        justify-content: space-between;
        padding: var(--space-3) var(--space-4);
        font-size: var(--text-base);
        border-bottom: 1px solid var(--color-bg-muted);
        border-radius: 0;
    }

    .nav-dropdown-menu {
        position: static;
        transform: none;
        box-shadow: none;
        border: none;
        opacity: 1;
        visibility: visible;
        display: none;
        background: var(--color-bg-subtle);
        padding: var(--space-2);
        margin: 0;
        border-radius: 0;
    }

    .nav-dropdown.open .nav-dropdown-menu {
        display: block;
    }

    .nav-dropdown.open .nav-chevron {
        transform: rotate(180deg);
    }

    .nav-cta {
        margin: var(--space-2);
        justify-content: center;
        padding: var(--space-3);
    }
}

/* ─────────────────────────────────────────────
   Back-to-Top button
   ───────────────────────────────────────────── */

.back-to-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--color-gray-900);
    color: var(--color-text-inverse);
    border: none;
    border-radius: 50%;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transform: translateY(10px);
    transition: all var(--transition-base);
    z-index: 999;
    box-shadow: var(--shadow-md);
}

.back-to-top:hover {
    background: var(--color-primary);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.back-to-top:focus-visible {
    outline: 2px solid var(--color-primary);
    outline-offset: 3px;
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.back-to-top svg {
    width: 20px;
    height: 20px;
}

@media (max-width: 640px) {
    .back-to-top {
        bottom: 1.5rem;
        right: 1.5rem;
        width: 40px;
        height: 40px;
    }
}