/* ========================================
   BOOKIFY - Smart Header & Navigation
   Modern, Clean, Accessible
   With Dark/Light Theme Support
======================================== */

/* Variables - Dark Theme (Default) */
:root {
    --header-height: 72px;
    --header-bg: rgba(255, 255, 255, 0.02);
    --header-bg-solid: rgba(10, 10, 20, 0.98);
    --header-border: rgba(255, 255, 255, 0.06);
    
    --text-white: #ffffff;
    --text-gray: #9ca3af;
    --text-muted: #6b7280;
    
    --primary: #3b82f6;
    --primary-dark: #2563eb;
    --accent: #8b5cf6;
    
    --mega-bg: #0c0c14;
    --mega-border: rgba(255, 255, 255, 0.08);
    --mega-hover: rgba(59, 130, 246, 0.08);
    
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    
    --shadow-lg: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
    --transition: 200ms ease;
}

/* Light Theme Variables */
[data-theme="light"] {
    --header-bg: rgba(255, 255, 255, 0.8);
    --header-bg-solid: rgba(255, 255, 255, 0.98);
    --header-border: rgba(0, 0, 0, 0.08);
    
    --text-white: #111827;
    --text-gray: #4b5563;
    --text-muted: #6b7280;
    
    --mega-bg: #ffffff;
    --mega-border: rgba(0, 0, 0, 0.08);
    --mega-hover: rgba(59, 130, 246, 0.06);
    
    --shadow-lg: 0 25px 50px -12px rgba(0, 0, 0, 0.15);
}

/* ========= Header ========= */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: var(--header-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--header-border);
    transition: background var(--transition), box-shadow var(--transition);
}

.header.scrolled {
    background: var(--header-bg-solid);
    box-shadow: var(--shadow-lg);
}

.header-inner {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 24px;
    height: var(--header-height);
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 32px;
}

/* ========= Logo ========= */
.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    text-decoration: none;
    flex-shrink: 0;
}

.logo-mark {
    width: 40px;
    height: 40px;
}

.logo-mark svg {
    width: 100%;
    height: 100%;
}

.logo-text {
    font-size: 1.375rem;
    font-weight: 700;
    color: var(--text-white);
    letter-spacing: -0.02em;
}

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

.nav-list {
    display: flex;
    align-items: center;
    gap: 4px;
    list-style: none;
    margin: 0;
    padding: 0;
}

.nav-item {
    position: relative;
}

.nav-link {
    display: flex;
    align-items: center;
    gap: 4px;
    padding: 10px 16px;
    font-size: 0.9375rem;
    font-weight: 500;
    color: var(--text-gray);
    text-decoration: none;
    background: none;
    border: none;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: color var(--transition), background var(--transition);
}

.nav-link:hover {
    color: var(--text-white);
    background: rgba(255, 255, 255, 0.05);
}

.nav-arrow {
    width: 12px;
    height: 12px;
    transition: transform var(--transition);
}

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

/* ========= Mega Menu ========= */
.mega-menu {
    position: absolute;
    top: calc(100% + 8px);
    left: 50%;
    transform: translateX(-50%);
    min-width: 600px;
    background: var(--mega-bg);
    border: 1px solid var(--mega-border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transition: opacity var(--transition), visibility var(--transition), transform var(--transition);
}

.nav-item:hover .mega-menu,
.nav-item.active .mega-menu {
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
}

/* Mega menu arrow */
.mega-menu::before {
    content: '';
    position: absolute;
    top: -6px;
    left: 50%;
    transform: translateX(-50%) rotate(45deg);
    width: 12px;
    height: 12px;
    background: var(--mega-bg);
    border-top: 1px solid var(--mega-border);
    border-left: 1px solid var(--mega-border);
}

.mega-inner {
    display: flex;
    padding: 8px;
}

.mega-section {
    flex: 1;
    min-width: 220px;
    padding: 16px;
}

.mega-section + .mega-section {
    border-left: 1px solid var(--mega-border);
}

.mega-title {
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-muted);
    margin: 0 0 12px 12px;
}

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

.mega-link {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    padding: 12px;
    text-decoration: none;
    border-radius: var(--radius-md);
    transition: background var(--transition);
}

.mega-link:hover {
    background: var(--mega-hover);
}

.mega-icon {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(59, 130, 246, 0.1);
    border-radius: var(--radius-sm);
    color: var(--primary);
    font-size: 1rem;
    flex-shrink: 0;
    transition: background var(--transition), transform var(--transition);
}

.mega-link:hover .mega-icon {
    background: var(--primary);
    color: white;
    transform: scale(1.05);
}

.mega-content {
    flex: 1;
    min-width: 0;
}

.mega-link-title {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.9375rem;
    font-weight: 600;
    color: var(--text-white);
    margin-bottom: 2px;
}

.mega-badge {
    font-size: 0.625rem;
    font-weight: 600;
    text-transform: uppercase;
    padding: 2px 6px;
    background: linear-gradient(135deg, var(--primary), var(--accent));
    color: white;
    border-radius: 4px;
}

.mega-link-desc {
    font-size: 0.8125rem;
    color: var(--text-muted);
    line-height: 1.4;
}

/* Mega Featured */
.mega-featured {
    width: 240px;
    padding: 16px;
    background: linear-gradient(135deg, rgba(59, 130, 246, 0.1), rgba(139, 92, 246, 0.1));
    border-radius: 0 var(--radius-lg) var(--radius-lg) 0;
    display: flex;
    align-items: center;
}

.mega-featured-content h4 {
    font-size: 1rem;
    font-weight: 700;
    color: var(--text-white);
    margin: 0 0 8px 0;
}

.mega-featured-content p {
    font-size: 0.8125rem;
    color: var(--text-gray);
    line-height: 1.5;
    margin: 0 0 16px 0;
}

.mega-featured-btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--primary);
    text-decoration: none;
    transition: gap var(--transition);
}

.mega-featured-btn:hover {
    gap: 12px;
}

/* ========= Header Actions ========= */
.header-actions {
    display: flex;
    align-items: center;
    gap: 12px;
    flex-shrink: 0;
}

/* Theme Toggle Button */
.theme-toggle {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: transparent;
    border: 1px solid var(--mega-border);
    border-radius: var(--radius-sm);
    cursor: pointer;
    position: relative;
    overflow: hidden;
    transition: border-color var(--transition), background var(--transition);
}

.theme-toggle:hover {
    border-color: var(--primary);
    background: var(--mega-hover);
}

.theme-toggle i {
    position: absolute;
    font-size: 1.1rem;
    transition: transform 0.4s ease, opacity 0.3s ease;
}

.theme-icon-light {
    color: #f59e0b;
    opacity: 0;
    transform: rotate(-90deg) scale(0.5);
}

.theme-icon-dark {
    color: var(--text-gray);
    opacity: 1;
    transform: rotate(0deg) scale(1);
}

/* Light theme icon states */
[data-theme="light"] .theme-icon-light {
    opacity: 1;
    transform: rotate(0deg) scale(1);
}

[data-theme="light"] .theme-icon-dark {
    opacity: 0;
    transform: rotate(90deg) scale(0.5);
}

.btn-login {
    padding: 10px 18px;
    font-size: 0.9375rem;
    font-weight: 500;
    color: var(--text-gray);
    text-decoration: none;
    border-radius: var(--radius-sm);
    transition: color var(--transition);
}

.btn-login:hover {
    color: var(--text-white);
}

.btn-cta {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 20px;
    font-size: 0.9375rem;
    font-weight: 600;
    color: white;
    text-decoration: none;
    background: linear-gradient(135deg, var(--primary), var(--accent));
    border-radius: var(--radius-sm);
    transition: transform var(--transition), box-shadow var(--transition);
}

.btn-cta:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(59, 130, 246, 0.4);
}

.btn-cta i {
    font-size: 0.75rem;
    transition: transform var(--transition);
}

.btn-cta:hover i {
    transform: translateX(4px);
}

/* ========= Mobile Toggle ========= */
.mobile-toggle {
    display: none;
    flex-direction: column;
    justify-content: center;
    gap: 6px;
    width: 40px;
    height: 40px;
    padding: 10px;
    background: none;
    border: 1px solid var(--mega-border);
    border-radius: var(--radius-sm);
    cursor: pointer;
}

.mobile-toggle span {
    display: block;
    height: 2px;
    background: var(--text-white);
    border-radius: 1px;
    transition: transform var(--transition), opacity var(--transition);
}

.mobile-toggle.active span:first-child {
    transform: rotate(45deg) translate(6px, 6px);
}

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

.mobile-toggle.active span:last-child {
    transform: rotate(-45deg) translate(6px, -6px);
}

/* ========= Responsive ========= */
@media (max-width: 1024px) {
    .mobile-toggle {
        display: flex;
    }
    
    .nav {
        position: fixed;
        top: var(--header-height);
        left: 0;
        right: 0;
        bottom: 0;
        background: var(--mega-bg);
        padding: 24px;
        transform: translateX(-100%);
        transition: transform 0.3s ease;
        overflow-y: auto;
    }
    
    .nav.active {
        transform: translateX(0);
    }
    
    .nav-list {
        flex-direction: column;
        align-items: stretch;
        gap: 0;
    }
    
    .nav-item {
        border-bottom: 1px solid var(--mega-border);
    }
    
    .nav-link {
        width: 100%;
        padding: 16px 0;
        justify-content: space-between;
    }
    
    .mega-menu {
        position: static;
        transform: none;
        min-width: 100%;
        border: none;
        border-radius: 0;
        box-shadow: none;
        background: rgba(255, 255, 255, 0.02);
        max-height: 0;
        overflow: hidden;
        opacity: 1;
        visibility: visible;
        pointer-events: auto;
    }
    
    .mega-menu::before {
        display: none;
    }
    
    .nav-item.active .mega-menu {
        max-height: 1000px;
        padding: 16px 0;
    }
    
    .mega-inner {
        flex-direction: column;
        padding: 0;
    }
    
    .mega-section {
        padding: 0;
        min-width: 100%;
    }
    
    .mega-section + .mega-section {
        border-left: none;
        border-top: 1px solid var(--mega-border);
        margin-top: 16px;
        padding-top: 16px;
    }
    
    .mega-featured {
        width: 100%;
        border-radius: var(--radius-md);
        margin-top: 16px;
    }
    
    .header-actions {
        display: none;
    }
}

@media (max-width: 640px) {
    .header-inner {
        padding: 0 16px;
    }
    
    .logo-text {
        font-size: 1.25rem;
    }
}

/* ========= Animations ========= */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(-8px); }
    to { opacity: 1; transform: translateY(0); }
}

.mega-menu .mega-link {
    animation: fadeIn 0.3s ease forwards;
    opacity: 0;
}

.nav-item:hover .mega-link:nth-child(1) { animation-delay: 0.05s; }
.nav-item:hover .mega-link:nth-child(2) { animation-delay: 0.1s; }
.nav-item:hover .mega-link:nth-child(3) { animation-delay: 0.15s; }
.nav-item:hover .mega-link:nth-child(4) { animation-delay: 0.2s; }