/* ===== QingPDF Navigation Bar Styles ===== */

:root {
    --nav-height: 76px;
    --primary-color: #0D9488;
    --primary-light: #14B8A6;
    --primary-dark: #0F766E;
    --primary-accent: #2DD4BF;
    --text-primary: #134E4A;
    --text-secondary: #475569;
    --text-muted: #64748B;
    --bg-glass: rgba(255, 255, 255, 0.92);
    --bg-glass-scrolled: rgba(255, 255, 255, 0.98);
    --border-subtle: rgba(13, 148, 136, 0.12);
    --shadow-soft: 0 4px 24px rgba(13, 148, 136, 0.10);
    --shadow-medium: 0 8px 40px rgba(13, 148, 136, 0.16);
}

* {
    box-sizing: border-box;
}

.qingpdf-nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 9999;
    background: var(--bg-glass);
    backdrop-filter: blur(32px) saturate(180%);
    -webkit-backdrop-filter: blur(32px) saturate(180%);
    border-bottom: 1px solid var(--border-subtle);
    transition: all 0.5s cubic-bezier(0.22, 0.61, 0.36, 1);
    height: var(--nav-height);
    display: flex;
    align-items: center;
    animation: navFadeIn 0.6s cubic-bezier(0.22, 0.61, 0.36, 1) 0.2s both;
}

@keyframes navFadeIn {
    from {
        opacity: 0;
        transform: translateY(-20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.qingpdf-nav::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 2px;
    background: linear-gradient(90deg, 
        transparent 0%, 
        #0D9488 20%, 
        #14B8A6 50%, 
        #2DD4BF 80%, 
        transparent 100%);
    opacity: 0;
    transition: opacity 0.5s ease;
}

.qingpdf-nav.scrolled {
    background: var(--bg-glass-scrolled);
    box-shadow: var(--shadow-soft);
    height: 68px;
}

.qingpdf-nav.scrolled::before {
    opacity: 1;
}

.qingpdf-nav-container {
    max-width: 1280px;
    width: 100%;
    margin: 0 auto;
    padding: 0 32px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
}

.qingpdf-logo {
    display: flex;
    align-items: center;
    gap: 12px;
    flex-shrink: 0;
    transition: transform 0.4s cubic-bezier(0.22, 0.61, 0.36, 1);
    text-decoration: none;
    position: relative;
    justify-self: start;
}

.qingpdf-logo::after {
    content: '';
    position: absolute;
    bottom: -8px;
    left: 50%;
    transform: translateX(-50%);
    width: 0;
    height: 3px;
    background: linear-gradient(90deg, #0D9488, #14B8A6, #2DD4BF);
    border-radius: 2px;
    transition: width 0.4s cubic-bezier(0.22, 0.61, 0.36, 1);
    opacity: 0;
}

.qingpdf-logo:hover::after {
    width: 60%;
    opacity: 1;
}

.qingpdf-logo:hover {
    transform: scale(1.03);
}

.qingpdf-logo img {
    width: 46px;
    height: 46px;
    border-radius: 16px;
    box-shadow: 0 8px 28px rgba(99, 102, 241, 0.28);
    transition: all 0.4s cubic-bezier(0.22, 0.61, 0.36, 1);
    animation: logoBounce 0.8s cubic-bezier(0.22, 0.61, 0.36, 1) 0.4s both;
}

@keyframes logoBounce {
    0% {
        opacity: 0;
        transform: scale(0.5);
    }
    50% {
        transform: scale(1.1);
    }
    100% {
        opacity: 1;
        transform: scale(1);
    }
}

.qingpdf-logo:hover img {
    box-shadow: 0 12px 40px rgba(99, 102, 241, 0.40);
    transform: scale(1.08) rotate(-3deg);
}

.qingpdf-logo-text {
    font-family: 'Outfit', sans-serif;
    font-weight: 700;
    font-size: 24px;
    color: #134E4A;
    letter-spacing: -0.5px;
    transition: color 0.4s ease, transform 0.4s ease;
    animation: textSlideIn 0.6s cubic-bezier(0.22, 0.61, 0.36, 1) 0.5s both;
}

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

.qingpdf-logo:hover .qingpdf-logo-text {
    color: #0D9488;
    transform: scale(1.02);
}

.qingpdf-nav-links {
    display: none;
    align-items: center;
    gap: 56px;
    animation: linksFadeIn 0.6s cubic-bezier(0.22, 0.61, 0.36, 1) 0.6s both;
    justify-self: center;
}

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

@media (min-width: 900px) {
    .qingpdf-nav-links {
        display: flex;
    }
}

.qingpdf-nav-item {
    position: relative;
    font-family: 'Manrope', sans-serif;
    font-weight: 600;
    font-size: 15px;
    color: var(--text-primary);
    text-decoration: none;
    transition: all 0.3s cubic-bezier(0.22, 0.61, 0.36, 1);
    padding: 22px 42px;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    border-radius: 12px;
    letter-spacing: -0.2px;
    overflow: hidden;
}

.qingpdf-nav-item::after {
    content: '';
    position: absolute;
    bottom: 6px;
    left: 50%;
    transform: translateX(-50%);
    width: 0;
    height: 2px;
    background: linear-gradient(90deg, #0D9488, #14B8A6);
    border-radius: 1px;
    transition: width 0.3s cubic-bezier(0.22, 0.61, 0.36, 1);
}

.qingpdf-nav-item:hover::after {
    width: calc(100% - 84px);
}

.qingpdf-nav-item:hover {
    color: var(--text-primary);
    background: linear-gradient(135deg, rgba(13, 148, 136, 0.08) 0%, rgba(20, 184, 166, 0.04) 100%);
    transform: translateY(-1px);
}

.qingpdf-nav-item.active {
    color: var(--text-primary);
    background: linear-gradient(135deg, rgba(13, 148, 136, 0.12) 0%, rgba(20, 184, 166, 0.06) 100%);
}

.qingpdf-nav-item.active::after {
    width: calc(100% - 84px);
}

.qingpdf-nav-dropdown {
    position: relative;
    display: inline-block;
    padding-bottom: 20px;
    margin-bottom: -20px;
}

.qingpdf-nav-dropdown::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: -20px;
    right: -20px;
    height: 20px;
}

.qingpdf-nav-dropdown-toggle {
    display: flex;
    align-items: center;
    gap: 6px;
}

.qingpdf-nav-dropdown-toggle i {
    font-size: 11px;
    transition: transform 0.3s cubic-bezier(0.22, 0.61, 0.36, 1);
}

.qingpdf-nav-dropdown:hover .qingpdf-nav-dropdown-toggle i {
    transform: rotate(180deg);
}

.qingpdf-dropdown-menu {
    display: none;
    position: absolute;
    top: 100%;
    left: 50%;
    transform: translateX(-50%);
    min-width: 260px;
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(32px) saturate(180%);
    -webkit-backdrop-filter: blur(32px) saturate(180%);
    border-radius: 20px;
    box-shadow: var(--shadow-medium);
    border: 1px solid var(--border-subtle);
    padding: 8px 0;
    z-index: 1000;
    overflow: hidden;
    transition: all 0.3s cubic-bezier(0.22, 0.61, 0.36, 1);
}

.qingpdf-dropdown-menu::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, #0D9488, #14B8A6, #2DD4BF);
    opacity: 0.85;
}

nav#qingpdfNav .qingpdf-nav-links .qingpdf-nav-dropdown .qingpdf-dropdown-menu.columns-3 {
    display: none !important;
    min-width: 450px !important;
    max-width: 90vw !important;
    padding: 10px 4px !important;
    grid-template-columns: repeat(3, 1fr) !important;
    gap: 0 !important;
    column-gap: 0 !important;
    left: 50% !important;
    transform: translateX(-50%) !important;
}

.qingpdf-nav-dropdown:hover .qingpdf-dropdown-menu {
    display: block;
    animation: qingpdfDropdownFadeIn 0.35s cubic-bezier(0.22, 0.61, 0.36, 1);
}

nav#qingpdfNav .qingpdf-nav-links .qingpdf-nav-dropdown:hover .qingpdf-dropdown-menu.columns-3 {
    display: grid !important;
}

@keyframes qingpdfDropdownFadeIn {
    from { 
        opacity: 0; 
        transform: translateX(-50%) translateY(-10px) scale(0.97);
        box-shadow: 0 4px 12px rgba(99, 102, 241, 0.06);
    }
    to { 
        opacity: 1; 
        transform: translateX(-50%) translateY(0) scale(1);
        box-shadow: var(--shadow-medium);
    }
}

.qingpdf-dropdown-item {
    display: flex;
    align-items: center;
    padding: 8px 14px;
    color: var(--text-primary);
    text-decoration: none;
    font-size: 14px;
    font-family: 'Manrope', sans-serif;
    font-weight: 500;
    transition: all 0.25s cubic-bezier(0.22, 0.61, 0.36, 1);
    white-space: nowrap;
    position: relative;
    margin: 1px 4px;
    border-radius: 8px;
}

.qingpdf-dropdown-item::before {
    content: '';
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 3px;
    height: 0;
    background: linear-gradient(180deg, #0D9488, #14B8A6);
    border-radius: 2px;
    opacity: 0;
    transition: all 0.25s cubic-bezier(0.22, 0.61, 0.36, 1);
}

.qingpdf-dropdown-item:hover {
    background: linear-gradient(135deg, rgba(13, 148, 136, 0.10) 0%, rgba(20, 184, 166, 0.05) 100%);
    color: #0D9488;
    padding-left: 28px;
    transform: translateX(2px);
}

.qingpdf-dropdown-item:hover::before {
    opacity: 1;
    height: 60%;
}

.qingpdf-dropdown-header {
    padding: 10px 20px 6px;
    font-size: 11px;
    font-weight: 700;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 1.2px;
    font-family: 'Outfit', sans-serif;
    position: relative;
}

.qingpdf-dropdown-header::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 20px;
    right: 20px;
    height: 1px;
    background: linear-gradient(90deg, transparent, rgba(13, 148, 136, 0.2), transparent);
}

.columns-3 .qingpdf-dropdown-header {
    padding: 8px 16px 4px;
    font-size: 10px;
    letter-spacing: 1px;
}

.columns-3 .qingpdf-dropdown-item {
    padding: 10px 16px;
    border-radius: 10px;
    font-size: 14px;
    margin: 2px 4px;
}

.columns-3 .qingpdf-dropdown-item:hover {
    background: linear-gradient(135deg, rgba(13, 148, 136, 0.10) 0%, rgba(20, 184, 166, 0.05) 100%);
    color: #0D9488;
    padding-left: 24px;
    transform: translateX(2px);
}

.columns-3 .qingpdf-dropdown-item:hover::before {
    opacity: 1;
    height: 60%;
}

.qingpdf-dropdown-section {
    display: flex;
    flex-direction: column;
    gap: 0;
}

.qingpdf-nav-spacer {
    justify-self: end;
    width: 100px;
}

.qingpdf-nav-actions {
    display: flex;
    align-items: center;
    gap: 12px;
    justify-self: end;
    order: 3;
}

.qingpdf-nav-toggle {
    display: flex;
    flex-direction: column;
    gap: 6px;
    padding: 10px;
    background: transparent;
    border: none;
    cursor: pointer;
    display: none;
    border-radius: 10px;
    transition: background 0.3s ease;
    justify-self: end;
}

.qingpdf-nav-toggle:hover {
    background: rgba(99, 102, 241, 0.08);
}

@media (max-width: 899px) {
    .qingpdf-nav-container {
        grid-template-columns: auto 1fr auto;
        padding: 0 16px;
    }

    .qingpdf-nav-toggle {
        display: flex;
        padding: 12px;
    }

    .qingpdf-nav-toggle span {
        width: 24px;
        height: 2.5px;
    }

    .qingpdf-nav-spacer {
        display: none;
    }
    
    .qingpdf-nav {
        height: 64px;
    }

    .qingpdf-nav.scrolled {
        height: 60px;
    }

    .qingpdf-nav-links {
        position: fixed;
        top: 64px;
        left: 0;
        right: 0;
        bottom: 0;
        background: rgba(255, 255, 255, 0.99);
        backdrop-filter: blur(32px) saturate(180%);
        flex-direction: column;
        padding: 20px;
        gap: 4px;
        box-shadow: var(--shadow-medium);
        border-bottom: 1px solid var(--border-subtle);
        display: none;
        overflow-y: auto;
        z-index: 9998;
    }

    .qingpdf-nav-links.active {
        display: flex;
        animation: slideDown 0.35s cubic-bezier(0.22, 0.61, 0.36, 1);
    }

    @keyframes slideDown {
        from { 
            opacity: 0; 
            transform: translateY(-12px);
        }
        to { 
            opacity: 1; 
            transform: translateY(0);
        }
    }

    .qingpdf-nav-item {
        padding: 16px 20px;
        border-radius: 12px;
        width: 100%;
        font-size: 16px;
        min-height: 48px;
    }

    .qingpdf-nav-item:hover {
        background: rgba(13, 148, 136, 0.08);
    }

    .qingpdf-nav-item:active {
        background: rgba(13, 148, 136, 0.12);
    }

    .qingpdf-dropdown-menu {
        position: static;
        transform: none !important;
        box-shadow: none;
        border: 1px solid var(--border-subtle);
        margin-top: 4px;
        margin-left: 12px;
        display: none;
        border-radius: 10px;
        width: calc(100% - 24px);
        max-height: 400px;
        overflow-y: auto;
    }

    .qingpdf-nav-dropdown:hover .qingpdf-dropdown-menu {
        display: block;
        animation: none;
    }

    .qingpdf-nav-links.active .qingpdf-dropdown:hover .qingpdf-dropdown-menu {
        display: block;
    }

    .qingpdf-dropdown-item {
        padding: 14px 16px;
        font-size: 15px;
    }

    .qingpdf-dropdown-header {
        padding: 12px 16px 8px;
    }
}

@media (max-width: 480px) {
    .qingpdf-nav-container {
        padding: 0 12px;
    }

    .qingpdf-logo-text {
        font-size: 20px;
    }

    .qingpdf-logo img {
        width: 40px;
        height: 40px;
    }

    .qingpdf-nav-item {
        padding: 14px 16px;
        font-size: 15px;
    }
}

.qingpdf-nav-toggle span {
    width: 26px;
    height: 2px;
    background: var(--text-primary);
    border-radius: 2px;
    transition: all 0.35s cubic-bezier(0.22, 0.61, 0.36, 1);
}

.qingpdf-nav-toggle.active span:nth-child(1) {
    transform: rotate(45deg) translateY(8px);
}

.qingpdf-nav-toggle.active span:nth-child(2) {
    opacity: 0;
    transform: scaleX(0.5);
}

.qingpdf-nav-toggle.active span:nth-child(3) {
    transform: rotate(-45deg) translateY(-8px);
}

.dark-mode-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border: none;
    background: transparent;
    border-radius: 10px;
    cursor: pointer;
    color: var(--text-primary);
    font-size: 18px;
    transition: all 0.3s ease;
    margin-right: 8px;
}

.dark-mode-toggle:hover {
    background: rgba(13, 148, 136, 0.08);
    color: var(--primary-color);
}

.dark-mode-toggle:active {
    background: rgba(13, 148, 136, 0.12);
}

@media (max-width: 899px) {
    .dark-mode-toggle {
        margin-right: 0;
    }
}

.dark .qingpdf-nav {
    background: rgba(15, 23, 42, 0.95);
    border-bottom-color: rgba(255, 255, 255, 0.1);
}

.dark .qingpdf-nav.scrolled {
    background: rgba(15, 23, 42, 0.98);
}

.dark .qingpdf-logo-text {
    color: #f1f5f9;
}

.dark .qingpdf-logo:hover .qingpdf-logo-text {
    color: #2dd4bf;
}

.dark .qingpdf-nav-item {
    color: #cbd5e1;
}

.dark .qingpdf-nav-item:hover {
    background: rgba(45, 212, 191, 0.1);
    color: #f1f5f9;
}

.dark .qingpdf-nav-item.active {
    background: rgba(45, 212, 191, 0.15);
    color: #f1f5f9;
}

.dark .qingpdf-dropdown-menu {
    background: rgba(30, 41, 59, 0.98);
    border-color: rgba(255, 255, 255, 0.1);
}

.dark .qingpdf-dropdown-item {
    color: #cbd5e1;
}

.dark .qingpdf-dropdown-item:hover {
    background: rgba(45, 212, 191, 0.1);
    color: #2dd4bf;
}

.dark .qingpdf-dropdown-header {
    color: #94a3b8;
}

.dark .qingpdf-nav-toggle span {
    background: #f1f5f9;
}

.dark .dark-mode-toggle {
    color: #cbd5e1;
}

.dark .dark-mode-toggle:hover {
    color: #2dd4bf;
}

.dark .qingpdf-lang-switcher {
    background: rgba(255, 255, 255, 0.05);
}

.dark .qingpdf-lang-btn {
    color: #cbd5e1;
}

.dark .qingpdf-lang-btn.active {
    background: rgba(45, 212, 191, 0.2);
    color: #2dd4bf;
}