/* ========================================
   有风无界 - 使用说明书样式（左右结构）
   ======================================== */

/* CSS Variables */
:root {
    --color-bg: #ffffff;
    --color-bg-secondary: #f8faf8;
    --color-text: #1d1d1f;
    --color-text-secondary: #6b6b6b;
    --color-accent: #4CAF50;
    --color-accent-hover: #43A047;
    --color-accent-light: #E8F5E9;
    --color-border: #e2e2e2;
    --color-card-bg: #ffffff;
    --color-card-shadow: rgba(0, 0, 0, 0.06);
    --color-highlight: #FFF8E1;
    --color-sidebar-bg: #fafcfa;
    
    --font-sans: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    
    --header-height: 60px;
    --sidebar-width: 280px;
    
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
}

/* Reset & Base */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-sans);
    font-size: 16px;
    line-height: 1.7;
    color: var(--color-text);
    background-color: var(--color-bg);
}

a {
    color: inherit;
    text-decoration: none;
}

button {
    font-family: inherit;
    cursor: pointer;
    border: none;
    background: none;
}

/* ========================================
   Header
   ======================================== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--header-height);
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    z-index: 1000;
    border-bottom: 1px solid var(--color-border);
}

.header .container {
    max-width: 100%;
    padding: 0 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 100%;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 18px;
    font-weight: 500;
}

.logo-img {
    height: 36px;
    width: auto;
}

.nav {
    display: flex;
    align-items: center;
    gap: 24px;
}

.nav-link {
    font-size: 14px;
    color: var(--color-text-secondary);
    transition: color var(--transition-fast);
}

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

.nav-link--cta {
    background: var(--color-accent);
    color: #fff;
    padding: 8px 16px;
    border-radius: 20px;
}

.nav-link--cta:hover {
    background: var(--color-accent-hover);
    color: #fff;
}

.menu-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    padding: 8px;
}

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

/* ========================================
   Layout (左右结构)
   ======================================== */
.layout {
    display: flex;
    margin-top: var(--header-height);
    min-height: calc(100vh - var(--header-height));
}

/* ========================================
   Sidebar
   ======================================== */
.sidebar {
    position: fixed;
    top: var(--header-height);
    left: 0;
    bottom: 0;
    width: var(--sidebar-width);
    background: var(--color-sidebar-bg);
    border-right: 1px solid var(--color-border);
    overflow-y: auto;
    z-index: 100;
}

.sidebar-header {
    padding: 24px 20px 16px;
    border-bottom: 1px solid var(--color-border);
}

.sidebar-title {
    display: block;
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 4px;
}

.sidebar-version {
    font-size: 12px;
    color: var(--color-text-secondary);
}

.sidebar-nav {
    padding: 12px 0;
}

.sidebar-link {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 20px;
    font-size: 14px;
    color: var(--color-text-secondary);
    transition: all var(--transition-fast);
    border-left: 3px solid transparent;
}

.sidebar-link:hover {
    color: var(--color-text);
    background: rgba(0, 0, 0, 0.03);
}

.sidebar-link.active {
    color: var(--color-accent);
    background: rgba(0, 113, 227, 0.05);
    border-left-color: var(--color-accent);
    font-weight: 500;
}

.sidebar-icon {
    font-size: 16px;
    width: 24px;
    text-align: center;
}

.sidebar-arrow {
    width: 16px;
    height: 16px;
    margin-left: auto;
    transition: transform var(--transition-fast);
}

.sidebar-link.expanded .sidebar-arrow {
    transform: rotate(90deg);
}

.sidebar-submenu {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease;
    padding: 0;
}

.sidebar-submenu.active {
    max-height: 500px;
}

.sidebar-link--sub {
    padding: 8px 20px 8px 54px;
    font-size: 13px;
    border-left: none;
}

.sidebar-link--sub.active {
    background: rgba(0, 113, 227, 0.08);
}

.sidebar-item {
    position: relative;
}

/* Sidebar Toggle (Mobile) */
.sidebar-toggle {
    display: none;
    position: fixed;
    bottom: 24px;
    left: 24px;
    width: 48px;
    height: 48px;
    background: var(--color-accent);
    color: #fff;
    border-radius: 50%;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 12px rgba(0, 113, 227, 0.3);
    z-index: 200;
}

.sidebar-toggle svg {
    width: 24px;
    height: 24px;
}

/* Sidebar Backdrop (Mobile) */
.sidebar-backdrop {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.4);
    z-index: 1100;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.sidebar-backdrop.active {
    display: block;
    opacity: 1;
}

/* ========================================
   Content
   ======================================== */
.content {
    flex: 1;
    margin-left: var(--sidebar-width);
    padding: 40px 60px 80px;
    max-width: 900px;
}

.content-section {
    margin-bottom: 60px;
    padding-bottom: 60px;
    border-bottom: 1px solid var(--color-border);
}

.content-section:last-of-type {
    border-bottom: none;
}

.section-badge {
    display: inline-block;
    padding: 4px 12px;
    background: var(--color-accent);
    color: #fff;
    border-radius: 12px;
    font-size: 12px;
    font-weight: 600;
    margin-bottom: 16px;
}

.content-title {
    font-size: 32px;
    font-weight: 600;
    letter-spacing: -0.02em;
    margin-bottom: 8px;
}

.content-subtitle {
    font-size: 16px;
    color: var(--color-text-secondary);
    margin-bottom: 32px;
}

/* ========================================
   Steps
   ======================================== */
.steps {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.step {
    display: flex;
    gap: 20px;
    padding: 24px;
    background: var(--color-bg-secondary);
    border-radius: 16px;
}

.step-number {
    width: 40px;
    height: 40px;
    background: var(--color-accent);
    color: #fff;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 18px;
    font-weight: 600;
    flex-shrink: 0;
}

.step-title {
    font-size: 17px;
    font-weight: 500;
    margin-bottom: 6px;
}

.step-desc {
    font-size: 14px;
    color: var(--color-text-secondary);
    line-height: 1.6;
}

/* ========================================
   Feature Blocks
   ======================================== */
.content-section--feature {
    padding: 32px;
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: 16px;
    margin-bottom: 24px;
}

.content-section--highlight {
    border-color: var(--color-accent);
    background: linear-gradient(180deg, rgba(76, 175, 80, 0.02) 0%, rgba(76, 175, 80, 0.05) 100%);
}

.feature-header {
    display: flex;
    align-items: center;
    gap: 16px;
    margin-bottom: 24px;
}

.feature-icon {
    width: 48px;
    height: 48px;
    padding: 10px;
    background: var(--color-bg-secondary);
    border-radius: 12px;
    color: var(--color-accent);
}

.feature-icon--highlight {
    background: var(--color-accent);
    color: #fff;
}

.feature-icon svg {
    width: 100%;
    height: 100%;
}

.feature-title {
    font-size: 20px;
    font-weight: 600;
    margin-bottom: 2px;
}

.feature-subtitle {
    font-size: 14px;
    color: var(--color-text-secondary);
}

/* Feature Grid */
.feature-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
}

.feature-item {
    padding: 16px;
    background: var(--color-bg-secondary);
    border-radius: 12px;
}

.feature-item h4 {
    font-size: 14px;
    font-weight: 500;
    margin-bottom: 8px;
}

.feature-item p {
    font-size: 13px;
    color: var(--color-text-secondary);
    line-height: 1.6;
}

/* Feature Content Layout */
.feature-content {
    display: grid;
    grid-template-columns: 1fr 240px;
    gap: 24px;
}

.feature-content--split {
    grid-template-columns: 1fr 1fr;
}

.feature-main h4 {
    font-size: 15px;
    font-weight: 500;
    margin-bottom: 12px;
}

.feature-sidebar-box h4 {
    font-size: 13px;
    font-weight: 500;
    margin-bottom: 12px;
    color: var(--color-text-secondary);
}

/* Feature Panel */
.feature-panel {
    padding: 20px;
    background: var(--color-bg-secondary);
    border-radius: 12px;
}

.feature-panel h4 {
    font-size: 15px;
    font-weight: 500;
    margin-bottom: 12px;
}

.feature-panel p {
    font-size: 13px;
    color: var(--color-text-secondary);
    margin-bottom: 12px;
}

/* Feature Lists */
.feature-list {
    padding-left: 18px;
}

.feature-list li {
    font-size: 13px;
    color: var(--color-text-secondary);
    line-height: 1.8;
}

.feature-list--check {
    list-style: none;
    padding-left: 0;
}

.feature-list--check li {
    padding-left: 18px;
    position: relative;
}

.feature-list--check li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--color-accent);
    font-weight: 600;
}

.feature-list--small li {
    font-size: 12px;
    line-height: 1.6;
}

/* Tags */
.tag-list {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
}

.tag {
    padding: 4px 10px;
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    border-radius: 10px;
    font-size: 11px;
    font-weight: 500;
    color: var(--color-accent);
}

/* Highlight Box */
.highlight-banner {
    padding: 16px 20px;
    background: var(--color-highlight);
    border-radius: 12px;
    margin-bottom: 20px;
}

.highlight-banner p {
    font-size: 14px;
    line-height: 1.7;
}

.highlight-box {
    padding: 16px;
    background: linear-gradient(135deg, #E8F5E9 0%, #C8E6C9 100%);
    border-radius: 12px;
}

.highlight-box p {
    font-size: 12px;
    font-weight: 500;
    margin-bottom: 6px;
    color: var(--color-text);
}

.highlight-box p:last-child {
    margin-bottom: 0;
}

/* ========================================
   Settings Grid
   ======================================== */
.settings-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
}

.setting-card {
    padding: 20px;
    background: var(--color-bg-secondary);
    border-radius: 12px;
}

.setting-icon {
    font-size: 24px;
    margin-bottom: 12px;
}

.setting-title {
    font-size: 15px;
    font-weight: 500;
    margin-bottom: 6px;
}

.setting-desc {
    font-size: 13px;
    color: var(--color-text-secondary);
    line-height: 1.5;
}

/* ========================================
   FAQ
   ======================================== */
.faq-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.faq-item {
    background: var(--color-bg-secondary);
    border-radius: 12px;
    overflow: hidden;
}

.faq-trigger {
    width: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 16px 20px;
    text-align: left;
    transition: color var(--transition-fast);
}

.faq-trigger:hover {
    color: var(--color-accent);
}

.faq-question {
    font-size: 14px;
    font-weight: 500;
}

.faq-arrow {
    width: 16px;
    height: 16px;
    flex-shrink: 0;
    transition: transform var(--transition-normal);
}

.faq-item.active .faq-arrow {
    transform: rotate(180deg);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height var(--transition-slow);
}

.faq-item.active .faq-answer {
    max-height: 300px;
    padding-bottom: 10px;
}

.faq-answer ul {
    padding-left: 18px;
}

.faq-answer li {
    font-size: 13px;
    color: var(--color-text-secondary);
    line-height: 1.8;
}

.faq-answer p {
    font-size: 13px;
    color: var(--color-text-secondary);
    line-height: 1.7;
    margin-bottom: 12px;
    padding: 0 20px;
}

.faq-answer p:first-child {
    padding-top: 0;
}

.faq-answer p:last-child {
    margin-bottom: 0;
}

.faq-answer ul {
    padding: 0 20px 16px 38px;
}

/* ========================================
   Content Footer
   ======================================== */
.content-footer {
    display: flex;
    gap: 16px;
    padding-top: 40px;
}

/* ========================================
   Buttons
   ======================================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 24px;
    font-size: 14px;
    font-weight: 500;
    border-radius: 20px;
    transition: all var(--transition-fast);
    cursor: pointer;
}

.btn--primary {
    background: var(--color-accent);
    color: #fff;
}

.btn--primary:hover {
    background: var(--color-accent-hover);
}

.btn--secondary {
    background: var(--color-bg-secondary);
    color: var(--color-text);
    border: 1px solid var(--color-border);
}

.btn--secondary:hover {
    background: var(--color-border);
}

/* ========================================
   Footer
   ======================================== */
.footer {
    margin-left: var(--sidebar-width);
    padding: 32px 60px;
    border-top: 1px solid var(--color-border);
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.footer-brand {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 16px;
    font-weight: 500;
}

.footer-logo-img {
    height: 28px;
    width: auto;
}

.footer-copyright {
    font-size: 12px;
    color: var(--color-text-secondary);
}

.footer-links {
    display: flex;
    gap: 20px;
}

.footer-links a {
    font-size: 13px;
    color: var(--color-text-secondary);
    transition: color var(--transition-fast);
}

.footer-links a:hover {
    color: var(--color-text);
}

/* ========================================
   Document Images
   ======================================== */
.doc-img {
    display: block;
    max-width: 100%;
    max-height: 520px;
    height: auto;
    object-fit: contain;
    border-radius: 12px;
    border: 1px solid var(--color-border);
    margin: 20px auto;
    box-shadow: 0 2px 12px var(--color-card-shadow);
    cursor: zoom-in;
    transition: box-shadow var(--transition-fast);
}

.doc-img:hover {
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.12);
}

.doc-img-group {
    display: flex;
    gap: 12px;
    justify-content: center;
    margin: 20px 0;
}

.doc-img-group .doc-img {
    flex: 1;
    max-width: 48%;
    margin: 0;
}

.doc-img-caption {
    text-align: center;
    font-size: 13px;
    color: var(--color-text-secondary);
    margin-top: -8px;
    margin-bottom: 20px;
}

/* ========================================
   Lightbox
   ======================================== */
.lightbox-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.92);
    z-index: 2000;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.25s ease, visibility 0.25s ease;
}

.lightbox-overlay.active {
    opacity: 1;
    visibility: visible;
}

.lightbox-container {
    position: relative;
    max-width: 90vw;
    max-height: 90vh;
    display: flex;
    align-items: center;
    justify-content: center;
}

.lightbox-img {
    max-width: 90vw;
    max-height: 88vh;
    object-fit: contain;
    border-radius: 6px;
    transition: transform 0.2s ease;
    user-select: none;
    -webkit-user-drag: none;
    cursor: zoom-in;
    will-change: transform;
}

.lightbox-img.dragging {
    cursor: grabbing;
}

.lightbox-close {
    position: fixed;
    top: 16px;
    right: 20px;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.15);
    border: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 2010;
    transition: background 0.2s ease;
}

.lightbox-close:hover {
    background: rgba(255, 255, 255, 0.3);
}

.lightbox-close svg {
    width: 20px;
    height: 20px;
    color: #fff;
}

.lightbox-nav {
    position: fixed;
    top: 50%;
    transform: translateY(-50%);
    width: 44px;
    height: 44px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.15);
    border: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 2010;
    transition: background 0.2s ease;
}

.lightbox-nav:hover {
    background: rgba(255, 255, 255, 0.3);
}

.lightbox-nav svg {
    width: 22px;
    height: 22px;
    color: #fff;
}

.lightbox-prev {
    left: 16px;
}

.lightbox-next {
    right: 16px;
}

.lightbox-toolbar {
    position: fixed;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 8px;
    background: rgba(0, 0, 0, 0.6);
    padding: 8px 12px;
    border-radius: 24px;
    z-index: 2010;
}

.lightbox-toolbar button {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.15);
    border: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background 0.2s ease;
}

.lightbox-toolbar button:hover {
    background: rgba(255, 255, 255, 0.3);
}

.lightbox-toolbar button svg {
    width: 18px;
    height: 18px;
    color: #fff;
}

.lightbox-counter {
    color: rgba(255, 255, 255, 0.7);
    font-size: 13px;
    display: flex;
    align-items: center;
    padding: 0 8px;
    white-space: nowrap;
}

/* ========================================
   Document Tables
   ======================================== */
.doc-table {
    width: 100%;
    border-collapse: collapse;
    margin: 16px 0 24px;
    font-size: 14px;
}

.doc-table th,
.doc-table td {
    padding: 10px 14px;
    text-align: left;
    border: 1px solid var(--color-border);
}

.doc-table th {
    background: var(--color-bg-secondary);
    font-weight: 500;
    font-size: 13px;
    color: var(--color-text-secondary);
}

.doc-table td {
    font-size: 13px;
    line-height: 1.6;
}

.doc-table tr:hover td {
    background: rgba(76, 175, 80, 0.02);
}

/* ========================================
   Document List
   ======================================== */
.doc-list {
    padding-left: 20px;
    margin: 12px 0;
}

.doc-list li {
    font-size: 14px;
    color: var(--color-text-secondary);
    line-height: 1.8;
    margin-bottom: 4px;
}

.doc-list li strong {
    color: var(--color-text);
    font-weight: 500;
}

/* ========================================
   Table Scroll Wrapper (Mobile)
   ======================================== */
.table-wrap {
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    margin: 16px 0 24px;
    border-radius: 8px;
    border: 1px solid var(--color-border);
}

.table-wrap .doc-table {
    margin: 0;
    min-width: 480px;
}

.table-wrap::-webkit-scrollbar {
    height: 4px;
}

.table-wrap::-webkit-scrollbar-track {
    background: transparent;
}

.table-wrap::-webkit-scrollbar-thumb {
    background: var(--color-border);
    border-radius: 2px;
}

/* ========================================
   Animations
   ======================================== */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.content-section {
    animation: fadeInUp 0.5s ease forwards;
}

/* ========================================
   Scrollbar
   ======================================== */
.sidebar::-webkit-scrollbar {
    width: 4px;
}

.sidebar::-webkit-scrollbar-track {
    background: transparent;
}

.sidebar::-webkit-scrollbar-thumb {
    background: var(--color-border);
    border-radius: 2px;
}

/* ========================================
   Responsive — Tablet (≤1024px)
   ======================================== */
@media (max-width: 1024px) {
    .content {
        padding: 32px 40px 80px;
    }

    .footer {
        padding: 32px 40px;
    }

    .sidebar {
        width: 240px;
    }

    :root {
        --sidebar-width: 240px;
    }
}

/* ========================================
   Responsive — Phone (≤768px)
   ======================================== */
@media (max-width: 768px) {
    :root {
        --header-height: 52px;
    }

    /* Prevent horizontal overflow */
    html, body {
        overflow-x: hidden;
    }

    /* --- Header --- */
    .nav {
        display: none;
    }

    .menu-toggle {
        display: flex;
    }

    .logo-text {
        font-size: 16px;
    }

    .logo-img {
        height: 28px;
    }

    /* --- Mobile Nav Drawer (right side, full height) --- */
    .nav-mobile {
        display: none;
    }

    .nav-mobile.active {
        display: flex;
        position: fixed;
        top: 0;
        right: 0;
        bottom: 0;
        width: 200px;
        background: var(--color-bg);
        flex-direction: column;
        align-items: stretch;
        justify-content: flex-start;
        gap: 0;
        padding: 16px 0;
        z-index: 1300;
        box-shadow: -4px 0 24px rgba(0, 0, 0, 0.15);
        overflow-y: auto;
    }

    /* Panel header: title + close button */
    .nav-mobile-header {
        display: flex;
        align-items: center;
        justify-content: space-between;
        padding: 8px 16px 14px;
        border-bottom: 1px solid var(--color-border);
        margin-bottom: 4px;
        animation: titleBounce 0.4s ease 0.15s both;
        cursor: pointer;
    }

    .nav-mobile-title {
        font-size: 15px;
        font-weight: 400;
        color: var(--color-accent);
    }

    .nav-close {
        display: flex;
        align-items: center;
        justify-content: center;
        width: 28px;
        height: 28px;
        border: none;
        background: rgba(0, 0, 0, 0.05);
        border-radius: 50%;
        cursor: pointer;
        color: var(--color-text-secondary);
        transition: background 0.2s, color 0.2s;
        flex-shrink: 0;
    }

    .nav-close:hover {
        background: rgba(0, 0, 0, 0.1);
        color: var(--color-text);
    }

    @keyframes titleBounce {
        0% { opacity: 0; transform: translateY(-8px); }
        60% { transform: translateY(2px); }
        100% { opacity: 1; transform: translateY(0); }
    }

    .nav-mobile.active .nav-link {
        font-size: 15px;
        padding: 13px 20px;
        border-bottom: 1px solid var(--color-border);
        color: var(--color-text-secondary);
    }

    .nav-mobile.active .nav-link:hover,
    .nav-mobile.active .nav-link:active {
        color: var(--color-text);
        background: rgba(0, 0, 0, 0.03);
    }

    .nav-mobile.active .nav-link--cta {
        background: var(--color-accent);
        color: #fff;
        border-radius: 0;
        margin: 0;
        padding: 14px 20px;
        font-weight: 500;
    }

    .nav-mobile.active .nav-link--cta:hover {
        background: var(--color-accent-hover);
        color: #fff;
    }

    /* Hamburger hides when menu is open */
    .menu-toggle.active {
        opacity: 0;
        pointer-events: none;
    }

    /* Nav Backdrop */
    .nav-backdrop {
        display: none;
        position: fixed;
        inset: 0;
        background: rgba(0, 0, 0, 0.4);
        z-index: 1200;
        opacity: 0;
        transition: opacity 0.3s ease;
    }

    .nav-backdrop.active {
        display: block;
        opacity: 1;
    }

    /* --- Sidebar Drawer --- */
    .sidebar {
        transform: translateX(-100%);
        transition: transform 0.3s ease;
        width: 280px;
        top: 0;
        z-index: 1200;
        box-shadow: none;
    }

    .sidebar.active {
        transform: translateX(0);
        box-shadow: 4px 0 24px rgba(0, 0, 0, 0.15);
    }

    .sidebar-toggle {
        display: flex;
    }

    /* --- Content --- */
    .content {
        margin-left: 0;
        padding: 24px 16px 100px;
        overflow-x: hidden;
    }

    .content-section {
        margin-bottom: 40px;
        padding-bottom: 40px;
        overflow-x: hidden;
    }

    .section-badge {
        font-size: 11px;
        padding: 3px 10px;
    }

    .content-title {
        font-size: 24px;
    }

    /* --- Tables (horizontal scroll) --- */
    .table-wrap {
        margin: 12px 0 20px;
        border-radius: 6px;
    }

    .table-wrap .doc-table {
        min-width: 420px;
        font-size: 13px;
    }

    .table-wrap .doc-table th,
    .table-wrap .doc-table td {
        padding: 8px 10px;
    }

    /* --- Images --- */
    .doc-img {
        max-height: 400px;
        border-radius: 8px;
        margin: 14px auto;
    }

    .doc-img-group {
        flex-direction: column;
        gap: 8px;
    }

    .doc-img-group .doc-img {
        max-width: 100%;
        max-height: 360px;
    }

    .doc-img-caption {
        font-size: 12px;
    }

    /* --- Lists --- */
    .doc-list li {
        font-size: 13px;
        line-height: 1.7;
    }

    /* --- FAQ --- */
    .faq-trigger {
        padding: 14px 16px;
        min-height: 48px;
    }

    .faq-question {
        font-size: 13px;
    }

    .faq-answer p {
        font-size: 12px;
        padding: 0 16px;
    }

    .faq-answer ul {
        padding: 0 16px 12px 32px;
    }

    /* --- Feature Grid --- */
    .feature-grid {
        grid-template-columns: 1fr;
        gap: 12px;
    }

    .feature-item {
        padding: 14px;
    }

    /* --- Feature Content --- */
    .feature-content {
        grid-template-columns: 1fr;
    }

    .feature-content--split {
        grid-template-columns: 1fr;
    }

    /* --- Settings Grid --- */
    .settings-grid {
        grid-template-columns: 1fr;
    }

    .setting-card {
        padding: 16px;
    }

    /* --- Steps --- */
    .step {
        padding: 16px;
        gap: 14px;
    }

    .step-number {
        width: 36px;
        height: 36px;
        font-size: 16px;
    }

    .step-title {
        font-size: 15px;
    }

    .step-desc {
        font-size: 13px;
    }

    /* --- Content Footer --- */
    .content-footer {
        padding-top: 28px;
    }

    .content-footer .btn {
        padding: 10px 18px;
        font-size: 13px;
    }

    /* --- Footer --- */
    .footer {
        margin-left: 0;
        padding: 24px 16px;
    }

    .footer-content {
        flex-direction: column;
        gap: 16px;
        text-align: center;
    }

    .footer-links {
        flex-wrap: wrap;
        justify-content: center;
        gap: 14px;
    }

    .footer-links a {
        font-size: 12px;
    }

    /* --- Lightbox --- */
    .lightbox-close {
        top: 12px;
        right: 12px;
        width: 36px;
        height: 36px;
    }

    .lightbox-close svg {
        width: 18px;
        height: 18px;
    }

    .lightbox-nav {
        width: 36px;
        height: 36px;
    }

    .lightbox-nav svg {
        width: 18px;
        height: 18px;
    }

    .lightbox-prev {
        left: 8px;
    }

    .lightbox-next {
        right: 8px;
    }

    .lightbox-toolbar {
        bottom: 12px;
        padding: 6px 10px;
        gap: 6px;
    }

    .lightbox-toolbar button {
        width: 32px;
        height: 32px;
    }

    .lightbox-toolbar button svg {
        width: 16px;
        height: 16px;
    }

    .lightbox-counter {
        font-size: 12px;
        padding: 0 6px;
    }
}

/* ========================================
   Responsive — Small Phone (≤480px)
   ======================================== */
@media (max-width: 480px) {
    .content {
        padding: 20px 14px 80px;
    }

    .content-title {
        font-size: 22px;
    }

    .section-badge {
        font-size: 10px;
    }

    .doc-img {
        max-height: 320px;
    }

    .doc-img-group .doc-img {
        max-height: 280px;
    }

    .sidebar {
        width: 260px;
    }

    .sidebar-link {
        padding: 9px 16px;
        font-size: 13px;
    }

    .sidebar-link--sub {
        padding: 7px 16px 7px 44px;
        font-size: 12px;
    }

    .sidebar-toggle {
        width: 44px;
        height: 44px;
        bottom: 20px;
        left: 20px;
    }
}

/* ========================================
   Responsive — Tiny Phone (≤360px)
   ======================================== */
@media (max-width: 360px) {
    .content {
        padding: 16px 12px 80px;
    }

    .content-title {
        font-size: 20px;
    }

    .content-section h2 {
        font-size: 16px !important;
    }

    .doc-img {
        max-height: 260px;
    }

    .doc-img-group .doc-img {
        max-height: 240px;
    }

    .sidebar {
        width: 240px;
    }

    .sidebar-header {
        padding: 18px 16px 12px;
    }

    .sidebar-title {
        font-size: 15px;
    }

    .faq-trigger {
        padding: 12px 14px;
    }

    .faq-question {
        font-size: 12px;
    }

    .faq-answer p {
        font-size: 11px;
    }
}

/* ========================================
   Back to Top Button
   ======================================== */
.back-to-top {
    position: fixed;
    bottom: 32px;
    right: 32px;
    width: 44px;
    height: 44px;
    background: var(--color-accent);
    color: #fff;
    border: none;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: all 0.3s ease;
    box-shadow: 0 4px 16px rgba(76, 175, 80, 0.3);
    z-index: 999;
}

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

.back-to-top:hover {
    background: var(--color-accent-hover);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(76, 175, 80, 0.4);
}

@media (max-width: 768px) {
    .back-to-top {
        bottom: 20px;
        right: 20px;
        width: 40px;
        height: 40px;
    }
}