/* ========================================
   MODERN HEADER NAVIGATION
   Vietnamese Book Reading Platform
   ======================================== */

/* ==================== MAIN HEADER ==================== */

.main-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1030;
    background: linear-gradient(135deg, #faf8f5 0%, #f4f1ec 50%, #ebe6df 100%);
    backdrop-filter: blur(10px);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 0 2px 8px rgba(139, 69, 19, 0.08);
    border-bottom: 1px solid rgba(139, 69, 19, 0.1);
}

/* Header with scroll shadow */
.main-header.scrolled {
    background: linear-gradient(135deg, rgba(250, 248, 245, 0.95) 0%, rgba(244, 241, 236, 0.95) 50%, rgba(235, 230, 223, 0.95) 100%);
    box-shadow: 0 4px 16px rgba(139, 69, 19, 0.12);
    border-bottom: 1px solid rgba(139, 69, 19, 0.15);
}

/* Add padding to body to prevent content from hiding under fixed header */
body {
    padding-top: 70px;
}

.main-header .navbar {
    padding: 0.75rem 0;
    background: transparent;
}

/* ==================== HEADER SECTIONS ==================== */

.main-header .container-fluid {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1.5rem;
}

/* LEFT SECTION: Brand/Logo */
.header-left {
    flex-shrink: 0;
}

.navbar-brand {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 700;
    font-size: 1.5rem;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    text-decoration: none;
    transition: all 0.3s ease;
    padding: 0;
    margin: 0;
}

.navbar-brand:hover {
    background: linear-gradient(135deg, var(--primary-dark) 0%, var(--secondary-dark) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    transform: scale(1.02);
}

.navbar-brand i {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--accent-color) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.navbar-brand i {
    font-size: 1.75rem;
}

.brand-text {
    letter-spacing: -0.5px;
}

/* CENTER SECTION: Primary Navigation */
.header-center {
    flex: 1;
    display: flex;
    justify-content: center;
    max-width: 600px;
    margin: 0 auto;
}

.main-nav {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin: 0;
    padding: 0;
    list-style: none;
}

.main-nav .nav-item {
    position: relative;
}

.main-nav .nav-link {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.625rem 1rem;
    color: var(--gray-700);
    font-weight: 500;
    font-size: 0.95rem;
    text-decoration: none;
    border-radius: 0.5rem;
    transition: all 0.3s ease;
    white-space: nowrap;
    position: relative;
    overflow: hidden;
}

.main-nav .nav-link::before {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    width: 0;
    height: 2px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    transform: translateX(-50%);
    transition: width 0.3s ease;
}

.main-nav .nav-link i {
    font-size: 1.1rem;
    transition: transform 0.3s ease;
}

.main-nav .nav-link:hover {
    color: var(--primary-color);
    background: linear-gradient(135deg, rgba(139, 69, 19, 0.05), rgba(47, 82, 51, 0.05));
}

.main-nav .nav-link:hover::before {
    width: 80%;
}

.main-nav .nav-link:hover i {
    transform: scale(1.1);
}

.main-nav .nav-link.active {
    color: var(--primary-color);
    background: linear-gradient(135deg, rgba(139, 69, 19, 0.1), rgba(47, 82, 51, 0.1));
    font-weight: 600;
}

.main-nav .nav-link.active::before {
    width: 80%;
}

/* RIGHT SECTION: Action Items */
.header-right {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    flex-shrink: 0;
}

/* ==================== MEGA MENU DROPDOWN ==================== */

.mega-menu {
    position: absolute;
    top: 100%;
    left: 50%;
    transform: translateX(-50%);
    margin-top: 0.5rem;
    background: linear-gradient(135deg, #faf8f5 0%, #f4f1ec 100%);
    border-radius: 1rem;
    box-shadow: 0 10px 40px rgba(139, 69, 19, 0.2), 0 0 0 1px rgba(139, 69, 19, 0.1);
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    pointer-events: none;
    min-width: 700px;
    max-width: 1024px;
    z-index: 1050;
    border: 1px solid rgba(139, 69, 19, 0.1);
}

.has-mega-menu:hover .mega-menu,
.mega-menu:hover {
    opacity: 1;
    visibility: visible;
    pointer-events: all;
    margin-top: 0.25rem;
}

.mega-menu-content {
    padding: 1.5rem;
}

.mega-menu-title {
    font-size: 1.1rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 1.25rem;
    padding-bottom: 0.75rem;
    border-bottom: 2px solid transparent;
    border-image: linear-gradient(90deg, var(--primary-color), var(--secondary-color), var(--accent-color)) 1;
}

.mega-menu-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem;
    border-radius: 0.5rem;
    text-decoration: none;
    color: var(--gray-700);
    transition: all 0.2s ease;
    background: #ffffff;
}

.mega-menu-item:hover {
    background: rgba(13, 110, 253, 0.05);
    color: var(--primary-color);
    transform: translateX(5px);
}

.mega-menu-item-icon {
    font-size: 1.75rem;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 0.5rem;
    background: var(--gray-100);
    flex-shrink: 0;
    transition: all 0.2s ease;
}

.mega-menu-item:hover .mega-menu-item-icon {
    background: var(--primary-color);
    color: #ffffff;
}

.mega-menu-item-info {
    flex: 1;
    min-width: 0;
}

.mega-menu-item-name {
    font-weight: 600;
    font-size: 0.95rem;
    margin-bottom: 0.125rem;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.mega-menu-item-count {
    font-size: 0.8rem;
    color: var(--gray-500);
}

/* ==================== SEARCH FUNCTIONALITY ==================== */

/* Search Toggle Button */
.btn-search-toggle {
    width: 40px;
    height: 40px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    border-radius: 0.5rem;
    border: none;
    background: var(--gray-100);
    color: var(--gray-700);
    font-size: 1.1rem;
    transition: all 0.2s ease;
    cursor: pointer;
}

.btn-search-toggle:hover {
    background: var(--primary-color);
    color: #ffffff;
    transform: scale(1.05);
}

/* Expandable Search Wrapper */
.search-wrapper {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(5px);
    z-index: 1040;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    display: flex;
    align-items: flex-start;
    justify-content: center;
    padding-top: 100px;
}

.search-wrapper.active {
    opacity: 1;
    visibility: visible;
}

.search-form {
    width: 100%;
    max-width: 600px;
    padding: 0 1rem;
    transform: translateY(-30px);
    transition: transform 0.3s ease;
}

.search-wrapper.active .search-form {
    transform: translateY(0);
}

.search-input-group {
    position: relative;
    display: flex;
    align-items: center;
    background: #ffffff;
    border-radius: 3rem;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
    overflow: hidden;
}

.search-input {
    flex: 1;
    border: none;
    padding: 1rem 1.5rem;
    font-size: 1.1rem;
    background: transparent;
}

.search-input:focus {
    outline: none;
    box-shadow: none;
}

.btn-search-submit,
.btn-search-close {
    width: 50px;
    height: 50px;
    display: flex;
    align-items: center;
    justify-content: center;
    border: none;
    background: transparent;
    color: var(--gray-600);
    font-size: 1.25rem;
    cursor: pointer;
    transition: all 0.2s ease;
    flex-shrink: 0;
}

.btn-search-submit:hover {
    color: var(--primary-color);
}

.btn-search-close:hover {
    color: var(--danger-color);
    transform: rotate(90deg);
}

/* Autocomplete Dropdown */
.autocomplete-dropdown {
    position: absolute;
    top: calc(100% + 0.5rem);
    left: 0;
    right: 0;
    background: #ffffff;
    border-radius: 1rem;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.15);
    max-height: 400px;
    overflow-y: auto;
    display: none;
}

.autocomplete-dropdown.show {
    display: block;
}

.autocomplete-item {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.875rem 1.25rem;
    text-decoration: none;
    color: var(--gray-800);
    border-bottom: 1px solid var(--gray-200);
    transition: all 0.2s ease;
}

.autocomplete-item:last-child {
    border-bottom: none;
}

.autocomplete-item:hover {
    background: rgba(13, 110, 253, 0.05);
    padding-left: 1.5rem;
}

.autocomplete-item img {
    width: 40px;
    height: 55px;
    object-fit: cover;
    border-radius: 0.25rem;
    flex-shrink: 0;
}

/* ==================== LIBRARY DROPDOWN ==================== */

.btn-library,
.btn-user,
.btn-login,
.btn-register {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.625rem 1rem;
    border-radius: 0.5rem;
    border: none;
    font-weight: 500;
    font-size: 0.95rem;
    transition: all 0.2s ease;
    cursor: pointer;
    white-space: nowrap;
    text-decoration: none;
}

.btn-library {
    background: var(--gray-100);
    color: var(--gray-700);
    position: relative;
}

.btn-library:hover {
    background: rgba(220, 53, 69, 0.1);
    color: var(--danger-color);
}

.badge-count {
    position: absolute;
    top: -5px;
    right: -5px;
    background: var(--danger-color);
    color: #ffffff;
    font-size: 0.7rem;
    font-weight: 700;
    padding: 0.15rem 0.4rem;
    border-radius: 1rem;
    min-width: 20px;
    text-align: center;
}

.library-menu {
    min-width: 350px;
    border-radius: 1rem;
    border: none;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.15);
    padding: 0;
    margin-top: 0.5rem !important;
}

.library-section {
    padding: 1rem;
}

.library-section-title {
    font-size: 0.85rem;
    font-weight: 700;
    color: var(--gray-700);
    margin-bottom: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.library-item {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem;
    border-radius: 0.5rem;
    text-decoration: none;
    color: var(--gray-800);
    transition: all 0.2s ease;
    margin-bottom: 0.5rem;
}

.library-item:last-child {
    margin-bottom: 0;
}

.library-item:hover {
    background: var(--gray-100);
}

.library-item-img {
    width: 40px;
    height: 60px;
    object-fit: cover;
    border-radius: 0.25rem;
    flex-shrink: 0;
}

.library-item-info {
    flex: 1;
    min-width: 0;
}

.library-item-title {
    font-weight: 600;
    font-size: 0.9rem;
    margin-bottom: 0.25rem;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.library-progress {
    height: 4px;
    background: var(--gray-200);
    border-radius: 2px;
    overflow: hidden;
}

.library-progress .progress-bar {
    background: linear-gradient(90deg, var(--primary-color), var(--primary-light));
}

.library-empty {
    text-align: center;
    padding: 1rem;
    color: var(--gray-500);
    font-size: 0.9rem;
}

.view-all-link {
    font-weight: 600;
    color: var(--primary-color);
    transition: all 0.2s ease;
}

.view-all-link:hover {
    color: var(--primary-dark);
    padding-left: 1.5rem;
}

/* ==================== USER DROPDOWN ==================== */

.btn-user {
    background: transparent;
    color: var(--gray-700);
}

.btn-user:hover {
    background: rgba(13, 110, 253, 0.05);
    color: var(--primary-color);
}

.user-avatar {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    color: #ffffff;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 0.9rem;
}

.user-name {
    font-weight: 600;
}

.user-menu {
    min-width: 280px;
    border-radius: 1rem;
    border: none;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.15);
    padding: 0;
    margin-top: 0.5rem !important;
}

.user-info {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.5rem;
}

.user-avatar-large {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    color: #ffffff;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.5rem;
    flex-shrink: 0;
}

.user-info-name {
    font-weight: 700;
    font-size: 1rem;
    color: var(--gray-800);
    margin-bottom: 0.125rem;
}

.user-info-email {
    font-size: 0.8rem;
    color: var(--gray-500);
}

.user-menu .dropdown-item {
    padding: 0.75rem 1.25rem;
    font-weight: 500;
    transition: all 0.2s ease;
}

.user-menu .dropdown-item:hover {
    background: rgba(13, 110, 253, 0.05);
    color: var(--primary-color);
    padding-left: 1.5rem;
}

.user-menu .dropdown-item i {
    margin-right: 0.75rem;
    width: 20px;
}

.admin-link {
    color: var(--warning-color) !important;
}

.admin-link:hover {
    background: rgba(255, 193, 7, 0.1) !important;
    color: #e0a800 !important;
}

.logout-link {
    color: var(--danger-color) !important;
    border: none;
    background: none;
    width: 100%;
    text-align: left;
}

.logout-link:hover {
    background: rgba(220, 53, 69, 0.05) !important;
    color: #c82333 !important;
}

/* ==================== GUEST BUTTONS ==================== */

.btn-login {
    background: transparent;
    color: var(--gray-700);
}

.btn-login:hover {
    background: rgba(13, 110, 253, 0.05);
    color: var(--primary-color);
}

.btn-register {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: #ffffff;
}

.btn-register:hover {
    background: linear-gradient(135deg, var(--primary-dark), var(--primary-color));
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(13, 110, 253, 0.3);
}

/* ==================== GENRES DROPDOWN STYLES ==================== */

/* Genres specific mega menu styling */
.genres-menu .mega-menu-item {
    position: relative;
    padding-left: 1rem;
}

.genres-menu .mega-menu-item::before {
    content: '';
    position: absolute;
    left: 0.5rem;
    top: 50%;
    transform: translateY(-50%);
    width: 4px;
    height: 70%;
    border-radius: 2px;
    background: var(--genre-color, var(--primary-color));
    transition: all 0.2s ease;
}

.genres-menu .mega-menu-item:hover::before {
    width: 6px;
    height: 85%;
}

.genre-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.25rem 0.75rem;
    border-radius: 1rem;
    font-size: 0.8rem;
    font-weight: 600;
    background: var(--genre-color, var(--primary-color));
    color: #ffffff;
}

.genre-badge-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.8);
}

/* Genre color indicator */
.genre-color-indicator {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    flex-shrink: 0;
    background: var(--genre-color, var(--primary-color));
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.mega-menu-item-name-wrapper {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

/* ==================== MOBILE MENU ==================== */

.btn-mobile-menu {
    width: 40px;
    height: 40px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    border-radius: 0.5rem;
    border: none;
    background: var(--gray-100);
    color: var(--gray-700);
    font-size: 1.5rem;
    transition: all 0.2s ease;
    cursor: pointer;
}

.btn-mobile-menu:hover {
    background: var(--primary-color);
    color: #ffffff;
}

.mobile-offcanvas {
    max-width: 320px;
}

.mobile-offcanvas .offcanvas-header {
    border-bottom: 1px solid var(--gray-200);
    padding: 1.25rem;
}

.mobile-offcanvas .offcanvas-title {
    font-weight: 700;
    color: var(--gray-800);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.mobile-offcanvas .offcanvas-body {
    padding: 1.25rem;
}

.mobile-search .input-group {
    border-radius: 0.5rem;
    overflow: hidden;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.mobile-search .form-control {
    border: none;
    padding: 0.75rem 1rem;
}

.mobile-search .btn {
    padding: 0.75rem 1.25rem;
}

.mobile-nav {
    list-style: none;
    padding: 0;
    margin: 0;
}

.mobile-nav li {
    margin-bottom: 0.5rem;
}

.mobile-nav-link {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.875rem 1rem;
    border-radius: 0.5rem;
    text-decoration: none;
    color: var(--gray-700);
    font-weight: 500;
    transition: all 0.2s ease;
    border: none;
    background: none;
    width: 100%;
    text-align: left;
}

.mobile-nav-link:hover {
    background: rgba(13, 110, 253, 0.05);
    color: var(--primary-color);
}

.mobile-nav-link i {
    font-size: 1.25rem;
    width: 24px;
}

.mobile-nav-link.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: #ffffff;
}

.mobile-nav-link.btn-primary:hover {
    background: linear-gradient(135deg, var(--primary-dark), var(--primary-color));
}

.mobile-nav-link.admin-link {
    color: var(--warning-color);
}

.mobile-nav-link.logout-link {
    color: var(--danger-color);
}

.mobile-nav-divider {
    height: 1px;
    background: var(--gray-200);
    margin: 0.75rem 0;
}

/* Mobile Nav Sections (Collapsible) */
.mobile-nav-section {
    margin-bottom: 0.5rem;
}

.mobile-nav-section-toggle {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.875rem 1rem;
    border-radius: 0.5rem;
    text-decoration: none;
    color: var(--gray-700);
    font-weight: 600;
    transition: all 0.2s ease;
    border: none;
    background: var(--gray-50);
    width: 100%;
    text-align: left;
}

.mobile-nav-section-toggle:hover {
    background: rgba(13, 110, 253, 0.05);
    color: var(--primary-color);
}

.mobile-nav-section-toggle i:first-child {
    font-size: 1.25rem;
    width: 24px;
}

.mobile-nav-section-toggle i:last-child {
    transition: transform 0.2s ease;
}

.mobile-nav-section-toggle[aria-expanded="true"] i:last-child {
    transform: rotate(180deg);
}

.mobile-nav-submenu {
    padding: 0.5rem 0 0 0;
}

.mobile-nav-submenu-loading {
    padding: 1rem;
}

.mobile-nav-submenu-item {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.75rem 1rem;
    margin-left: 1.5rem;
    border-radius: 0.5rem;
    text-decoration: none;
    color: var(--gray-700);
    font-weight: 500;
    transition: all 0.2s ease;
    border-left: 3px solid transparent;
}

.mobile-nav-submenu-item:hover {
    background: rgba(13, 110, 253, 0.05);
    color: var(--primary-color);
    border-left-color: var(--primary-color);
}

.mobile-nav-submenu-item.genre-item {
    border-left-color: var(--genre-color, var(--primary-color));
}

.mobile-nav-submenu-item.genre-item:hover {
    border-left-color: var(--genre-color, var(--primary-color));
    background: rgba(var(--genre-color-rgb, 13, 110, 253), 0.05);
}

.mobile-genre-color {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--genre-color, var(--primary-color));
    flex-shrink: 0;
}

.mobile-nav-submenu-count {
    margin-left: auto;
    font-size: 0.8rem;
    color: var(--gray-500);
    font-weight: 600;
}

/* ==================== RESPONSIVE DESIGN ==================== */

@media (max-width: 1199px) {
    .main-nav .nav-link {
        padding: 0.625rem 0.75rem;
        font-size: 0.9rem;
    }

    .mega-menu {
        min-width: 600px;
    }
}

@media (max-width: 991px) {
    body {
        padding-top: 60px;
    }

    .main-header .navbar {
        padding: 0.5rem 0;
    }

    .navbar-brand {
        font-size: 1.25rem;
    }

    .navbar-brand i {
        font-size: 1.5rem;
    }

    .header-center {
        display: none !important;
    }
}

@media (max-width: 767px) {
    .search-wrapper {
        padding-top: 80px;
    }

    .search-form {
        max-width: 100%;
    }

    .search-input {
        padding: 0.875rem 1.25rem;
        font-size: 1rem;
    }
}

@media (max-width: 575px) {
    .navbar-brand .brand-text {
        display: none;
    }

    .header-right {
        gap: 0.5rem;
    }
}

/* ==================== ANIMATIONS ==================== */

@keyframes slideDown {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

.dropdown-menu.show {
    animation: slideDown 0.2s ease;
}

.mega-menu {
    animation: slideDown 0.3s ease;
}

/* ==================== ACCESSIBILITY ==================== */

.btn:focus,
.nav-link:focus,
.dropdown-item:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

/* High contrast for better readability */
@media (prefers-contrast: high) {
    .main-header {
        border-bottom: 2px solid var(--gray-800);
    }

    .nav-link {
        font-weight: 600;
    }
}

/* Reduced motion for users who prefer it */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}