/* ==========================================================================
   Yandex入口导航 - 样式表
   Mobile-first, SEO-friendly, Performance-optimized
   ========================================================================== */

/* CSS Variables */
:root {
    /* Colors - Primary (Refined Red) */
    --primary-color: #e53935;
    --primary-dark: #c62828;
    --primary-light: #ff5252;
    --primary-rgb: 229, 57, 53;

    /* Colors - Secondary */
    --secondary-color: #1a1a2e;
    --secondary-light: #2d2d4a;
    --secondary-rgb: 26, 26, 46;

    /* Colors - Neutral */
    --text-color: #1e293b;
    --text-light: #64748b;
    --text-muted: #94a3b8;
    --white: #ffffff;
    --gray-light: #cccccc;
    --gray-muted: #aaaaaa;
    --gray-dark: #999999;
    --bg-color: var(--white);
    --bg-light: #f8fafc;
    --bg-dark: #1a1a2e;
    --border-color: #e2e8f0;

    /* Shadows - Layered */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-md: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-lg: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    --shadow-xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
    --shadow-primary: 0 10px 40px -10px rgba(229, 57, 53, 0.4);
    --shadow-card-hover: 0 20px 40px -15px rgba(0, 0, 0, 0.15);

    /* Borders & Radius */
    --radius-sm: 6px;
    --radius: 10px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --radius-full: 9999px;

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition: 250ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 350ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-bounce: 500ms cubic-bezier(0.34, 1.56, 0.64, 1);

    /* Layout */
    --max-width: 1200px;

    /* Common Gradients */
    --gradient-primary: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    --gradient-primary-90: linear-gradient(90deg, var(--primary-color), var(--primary-light));
}

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

html {
    font-size: 16px;
    scroll-behavior: smooth;
    -webkit-text-size-adjust: 100%;
}

body {
    font-family: 'Inter', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    font-size: 1rem;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

a {
    color: var(--primary-color);
    text-decoration: none;
    transition: var(--transition);
}

a:hover {
    color: var(--primary-dark);
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

ul {
    list-style: none;
}

code {
    background: var(--bg-light);
    padding: 0.2em 0.5em;
    border-radius: 4px;
    font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
    font-size: 0.9em;
}

/* Container */
.container {
    width: 100%;
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 20px;
}

/* ==========================================================================
   Common Section Styles
   ========================================================================== */

/* Section Titles - Unified styles for all section h2 elements */
.intro h2,
.guide h2,
.services h2,
.faq h2,
.comparison h2,
.tips h2,
.related h2,
.reviews-section h2,
.research-section h2 {
    text-align: center;
    color: var(--secondary-color);
}

/* Rating badges - Unified base styles */
.rating-high,
.rating-medium,
.rating-low {
    font-weight: 600;
    padding: 4px 12px;
    border-radius: var(--radius-full);
    display: inline-block;
    white-space: nowrap;
}

/* Fix: Preserve table-cell display for td elements with rating classes */
td.rating-high,
td.rating-medium,
td.rating-low {
    display: table-cell;
    text-align: center;
}

/* ==========================================================================
   Header
   ========================================================================== */
.header {
    position: sticky;
    top: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(12px) saturate(1.8);
    -webkit-backdrop-filter: blur(12px) saturate(1.8);
    border-bottom: 1px solid rgba(226, 232, 240, 0.8);
    padding: 15px 0;
    transition: var(--transition);
}

.header.scrolled {
    background: rgba(255, 255, 255, 0.95);
    box-shadow: var(--shadow-md);
}

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

.logo-text {
    font-size: 1.5rem;
    font-weight: 700;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

.nav-list {
    display: flex;
    gap: 25px;
}

.nav-list a {
    color: var(--text-color);
    font-weight: 500;
    padding: 8px 0;
    position: relative;
}

.nav-list a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--gradient-primary-90);
    transition: width var(--transition);
}

.nav-list a:hover {
    color: var(--primary-color);
}

.nav-list a:hover::after {
    width: 100%;
}

/* Mobile Navigation */
@media (max-width: 768px) {
    .nav-list {
        gap: 15px;
        font-size: 0.9rem;
    }
}

/* ==========================================================================
   Hero Section
   ========================================================================== */
.hero {
    background: linear-gradient(135deg, var(--bg-dark) 0%, var(--secondary-light) 50%, #0f3460 100%);
    background-size: 200% 200%;
    animation: gradient-shift 15s ease infinite;
    color: var(--white);
    padding: 80px 0;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(
        circle at 50% 50%,
        rgba(229, 57, 53, 0.1) 0%,
        rgba(229, 57, 53, 0.05) 30%,
        transparent 60%
    );
    animation: float 8s ease-in-out infinite;
    pointer-events: none;
}

.hero h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 20px;
    line-height: 1.3;
    position: relative;
    z-index: 1;
}

.hero-desc {
    font-size: 1.15rem;
    color: rgba(255, 255, 255, 0.85);
    max-width: 700px;
    margin: 0 auto 40px;
    position: relative;
    z-index: 1;
}

.hero-desc strong {
    color: var(--white);
}

/* Entry Box with Glassmorphism */
.entry-box {
    background: rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-xl);
    padding: 45px;
    max-width: 620px;
    margin: 0 auto;
    backdrop-filter: blur(20px) saturate(1.8);
    -webkit-backdrop-filter: blur(20px) saturate(1.8);
    border: 1px solid rgba(255, 255, 255, 0.2);
    box-shadow: 
        0 8px 32px rgba(0, 0, 0, 0.2),
        inset 0 1px 1px rgba(255, 255, 255, 0.1);
    position: relative;
    z-index: 1;
}

.entry-box h2 {
    font-size: 1.6rem;
    margin-bottom: 25px;
    font-weight: 600;
}

/* Buttons */
.entry-links {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    padding: 16px 32px;
    font-size: 1.1rem;
    font-weight: 600;
    border-radius: var(--radius-lg);
    cursor: pointer;
    transition: all var(--transition);
    text-align: center;
    position: relative;
    overflow: hidden;
}

.btn-primary {
    background: var(--gradient-primary);
    color: var(--white);
    box-shadow: var(--shadow-primary);
}

.btn-primary::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(
        90deg,
        transparent,
        rgba(255, 255, 255, 0.3),
        transparent
    );
    transition: left 0.5s ease;
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 15px 35px -10px rgba(229, 57, 53, 0.5);
    color: var(--white);
}

.btn-primary:hover::before {
    left: 100%;
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.15);
    color: var(--white);
    border: 1px solid rgba(255, 255, 255, 0.3);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.25);
    border-color: rgba(255, 255, 255, 0.5);
    color: var(--white);
    transform: translateY(-3px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
}

.btn-arrow {
    transition: transform var(--transition-bounce);
}

.btn:hover .btn-arrow {
    transform: translateX(5px);
}

.entry-note {
    margin-top: 25px;
    font-size: 0.95rem;
    color: rgba(255, 255, 255, 0.7);
    font-weight: 500;
}

@media (min-width: 480px) {
    .entry-links {
        flex-direction: row;
        justify-content: center;
    }
}

@media (max-width: 768px) {
    .hero {
        padding: 60px 0;
    }
    .hero h1 {
        font-size: 2rem;
    }
    .entry-box {
        padding: 30px 20px;
    }
}

/* ==========================================================================
   Introduction Section
   ========================================================================== */
.intro {
    padding: 60px 0;
    background: var(--bg-light);
}

.intro h2 {
    font-size: 1.8rem;
    margin-bottom: 30px;
}

.intro-content {
    display: grid;
    grid-template-columns: 1fr;
    gap: 40px;
    align-items: center;
}

.intro-text p {
    margin-bottom: 15px;
    color: var(--text-light);
}

.intro-text p:last-child {
    margin-bottom: 0;
}

.intro-stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
    text-align: center;
}

.stat-item {
    background: var(--bg-color);
    padding: 30px 20px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
    transition: all var(--transition);
    position: relative;
    overflow: hidden;
}

.stat-item::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--gradient-primary-90);
}

.stat-item:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.stat-number {
    display: block;
    font-size: 2.5rem;
    font-weight: 700;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 8px;
}

.stat-label {
    font-size: 0.9rem;
    color: var(--text-light);
    font-weight: 500;
}


@media (min-width: 768px) {
    .intro-content {
        grid-template-columns: 2fr 1fr;
    }
}

/* ==========================================================================
   Guide Section
   ========================================================================== */
.guide {
    padding: 60px 0;
}

.guide h2 {
    font-size: 1.8rem;
    margin-bottom: 15px;
}

.section-desc {
    text-align: center;
    color: var(--text-light);
    max-width: 600px;
    margin: 0 auto 40px;
}

.guide-steps {
    display: grid;
    gap: 25px;
    max-width: 800px;
    margin: 0 auto;
}

.step {
    display: flex;
    gap: 25px;
    align-items: flex-start;
    background: var(--bg-color);
    padding: 30px;
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-color);
    transition: all var(--transition);
    box-shadow: var(--shadow-sm);
}

.step:hover {
    border-color: var(--primary-color);
    box-shadow: var(--shadow-md);
    transform: translateX(5px);
}

.step-number {
    flex-shrink: 0;
    width: 50px;
    height: 50px;
    background: var(--gradient-primary);
    color: var(--white);
    font-size: 1.3rem;
    font-weight: 700;
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-primary);
    transition: var(--transition);
}

.step:hover .step-number {
    transform: scale(1.1) rotate(5deg);
}

.step-content h3 {
    font-size: 1.15rem;
    margin-bottom: 12px;
    color: var(--secondary-color);
    font-weight: 600;
}

.step-content p {
    color: var(--text-light);
    font-size: 0.95rem;
    line-height: 1.7;
}

/* ==========================================================================
   Services Section
   ========================================================================== */
.services {
    padding: 80px 0;
    background: var(--bg-light);
}

.services h2 {
    font-size: 2rem;
    margin-bottom: 15px;
}

.services-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 25px;
    margin-top: 50px;
}

.service-card {
    background: var(--bg-color);
    padding: 32px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
    transition: all var(--transition);
    position: relative;
    overflow: hidden;
    border: 1px solid transparent;
}

.service-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 0;
    background: linear-gradient(180deg, var(--primary-color), var(--primary-light));
    transition: height var(--transition);
}

.service-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-card-hover);
    border-color: rgba(229, 57, 53, 0.1);
}

.service-card:hover::before {
    height: 100%;
}

.service-icon {
    font-size: 2.5rem;
    margin-bottom: 15px;
}

.service-card h3 {
    font-size: 1.25rem;
    margin-bottom: 12px;
    color: var(--secondary-color);
    font-weight: 600;
}

.service-card p {
    color: var(--text-light);
    font-size: 0.95rem;
    margin-bottom: 18px;
    line-height: 1.7;
}

.service-link {
    font-weight: 600;
    font-size: 0.95rem;
    display: inline-flex;
    align-items: center;
    gap: 6px;
    transition: var(--transition);
}

.service-link:hover {
    gap: 10px;
}

/* ==========================================================================
   FAQ Section
   ========================================================================== */
.faq {
    padding: 80px 0;
}

.faq h2 {
    font-size: 2rem;
    margin-bottom: 50px;
}

.faq-list {
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 25px 30px;
    margin-bottom: 15px;
    background: var(--bg-color);
    transition: all var(--transition);
}

.faq-item:hover {
    border-color: var(--primary-color);
    box-shadow: var(--shadow);
}

.faq-question {
    font-size: 1.15rem;
    font-weight: 600;
    color: var(--secondary-color);
    margin-bottom: 15px;
    cursor: default;
    display: flex;
    align-items: flex-start;
    gap: 12px;
}

.faq-question::before {
    content: 'Q';
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 28px;
    height: 28px;
    background: var(--gradient-primary);
    color: var(--white);
    border-radius: var(--radius);
    font-size: 0.85rem;
    font-weight: 700;
}

.faq-answer {
    color: var(--text-light);
    line-height: 1.8;
    padding-left: 40px;
}

.faq-answer p {
    margin-bottom: 12px;
}

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

/* ==========================================================================
   Related Section
   ========================================================================== */
.related {
    padding: 50px 0;
    background: var(--bg-light);
}

.related h2 {
    font-size: 1.4rem;
    margin-bottom: 30px;
}

.related-tags {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 12px;
}

.tag {
    background: var(--bg-color);
    color: var(--text-light);
    padding: 10px 20px;
    border-radius: var(--radius-full);
    font-size: 0.9rem;
    border: 1px solid var(--border-color);
    transition: all var(--transition);
    font-weight: 500;
}

a.tag:hover {
    background: var(--gradient-primary);
    color: var(--white);
    border-color: var(--primary-color);
    transform: translateY(-2px);
    box-shadow: var(--shadow-primary);
}

/* ==========================================================================
   Footer
   ========================================================================== */
.footer {
    background: linear-gradient(135deg, var(--bg-dark) 0%, #0f172a 100%);
    color: var(--gray-light);
    padding: 60px 0 30px;
    position: relative;
}

.footer::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--primary-light), var(--primary-color));
    background-size: 200% 100%;
    animation: gradient-shift 3s linear infinite;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 40px;
    margin-bottom: 50px;
}

.footer-section h4 {
    color: var(--white);
    font-size: 1.15rem;
    margin-bottom: 20px;
    position: relative;
    padding-bottom: 10px;
}

.footer-section h4::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 40px;
    height: 2px;
    background: var(--primary-color);
}

.footer-section p {
    font-size: 0.9rem;
    line-height: 1.8;
}

.footer-section ul li {
    margin-bottom: 12px;
}

.footer-section a {
    color: var(--gray-light);
    font-size: 0.9rem;
    transition: var(--transition);
    display: inline-block;
}

.footer-section a:hover {
    color: var(--primary-color);
    padding-left: 5px;
}

.footer-bottom {
    text-align: center;
    padding-top: 30px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    font-size: 0.85rem;
}

/* ==========================================================================
   Utility Classes
   ========================================================================== */
.text-center {
    text-align: center;
}

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* ==========================================================================
   Breadcrumb Navigation
   ========================================================================== */
.breadcrumb {
    background: var(--bg-light);
    padding: 12px 0;
    border-bottom: 1px solid var(--border-color);
}

.breadcrumb-list {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.85rem;
}

.breadcrumb-item {
    display: flex;
    align-items: center;
}

.breadcrumb-item:not(:last-child)::after {
    content: "›";
    margin-left: 8px;
    color: var(--text-light);
}

.breadcrumb-item a {
    color: var(--text-light);
}

.breadcrumb-item a:hover {
    color: var(--primary-color);
}

.breadcrumb-item.active {
    color: var(--text-color);
    font-weight: 500;
}

/* ==========================================================================
   Article Meta (E-E-A-T)
   ========================================================================== */
.article-meta {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 20px;
    margin-bottom: 30px;
    font-size: 0.9rem;
    color: var(--gray-muted);
}

.meta-item {
    display: flex;
    align-items: center;
    gap: 6px;
}

.meta-icon {
    opacity: 0.8;
}

/* ==========================================================================
   Hero Screenshot
   ========================================================================== */
.hero-screenshot {
    margin-top: 40px;
    text-align: center;
}

.hero-screenshot img {
    border-radius: var(--radius);
    box-shadow: var(--shadow-lg);
    margin: 0 auto;
}

.hero-screenshot figcaption {
    margin-top: 12px;
    font-size: 0.85rem;
    color: var(--gray-muted);
}

/* ==========================================================================
   Timeline Section
   ========================================================================== */
.timeline-section {
    margin-top: 60px;
}

.timeline-section h3 {
    text-align: center;
    font-size: 1.5rem;
    margin-bottom: 40px;
    color: var(--secondary-color);
}

.timeline {
    position: relative;
    max-width: 700px;
    margin: 0 auto;
    padding-left: 35px;
}

.timeline::before {
    content: "";
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 4px;
    background: linear-gradient(180deg, var(--primary-color), var(--primary-light), var(--primary-color));
    border-radius: 2px;
}

.timeline-item {
    position: relative;
    padding: 0 0 35px 30px;
    transition: var(--transition);
}

.timeline-item:last-child {
    padding-bottom: 0;
}

.timeline-item::before {
    content: "";
    position: absolute;
    left: -39px;
    top: 5px;
    width: 14px;
    height: 14px;
    background: var(--primary-color);
    border-radius: 50%;
    border: 3px solid var(--bg-light);
    box-shadow: 0 0 0 3px var(--primary-color);
    transition: var(--transition);
}

.timeline-item:hover::before {
    transform: scale(1.3);
    box-shadow: 0 0 0 5px rgba(229, 57, 53, 0.3);
}

.timeline-year {
    display: inline-block;
    background: var(--gradient-primary);
    color: var(--white);
    padding: 6px 16px;
    border-radius: var(--radius);
    font-weight: 700;
    font-size: 0.9rem;
    margin-bottom: 10px;
    box-shadow: var(--shadow-sm);
}

.timeline-item p {
    color: var(--text-light);
    font-size: 0.95rem;
    line-height: 1.7;
}

/* ==========================================================================
   Comparison Section
   ========================================================================== */
.comparison {
    padding: 80px 0;
}

.comparison h2 {
    font-size: 2rem;
    margin-bottom: 15px;
}

.comparison-table-wrapper {
    overflow-x: auto;
    margin: 50px 0;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
}

.comparison-table {
    width: 100%;
    border-collapse: collapse;
    background: var(--bg-color);
    border-radius: var(--radius-lg);
    overflow: hidden;
}

.comparison-table th,
.comparison-table td {
    padding: 16px 20px;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
    vertical-align: middle;
}

/* 功能特性列 */
.comparison-table th:nth-child(1),
.comparison-table td:nth-child(1) {
    width: 180px;
}

/* Yandex列 */
.comparison-table th:nth-child(2),
.comparison-table td:nth-child(2) {
    width: 120px;
    text-align: center;
}

/* Google列 */
.comparison-table th:nth-child(3),
.comparison-table td:nth-child(3) {
    width: 120px;
    text-align: center;
}

/* 评价列 - 自动填充剩余空间 */
.comparison-table th:nth-child(4),
.comparison-table td:nth-child(4) {
    /* 不设置宽度，自动填充 */
}

.comparison-table th {
    background: linear-gradient(135deg, var(--secondary-color) 0%, var(--secondary-light) 100%);
    color: var(--white);
    font-weight: 600;
    font-size: 0.95rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.comparison-table tbody tr {
    transition: var(--transition);
}

.comparison-table tbody tr:nth-child(even) {
    background: var(--bg-light);
}

.comparison-table tbody tr:hover {
    background: rgba(229, 57, 53, 0.05);
}

.comparison-table tbody tr:last-child td {
    border-bottom: none;
}

.rating-high {
    color: #16a34a;
    background: rgba(22, 163, 74, 0.1);
}

.rating-medium {
    color: #d97706;
    background: rgba(217, 119, 6, 0.1);
}

.rating-low {
    color: #dc2626;
    background: rgba(220, 38, 38, 0.1);
}

.comparison-summary {
    margin-top: 40px;
}

.comparison-summary h3 {
    text-align: center;
    font-size: 1.4rem;
    margin-bottom: 25px;
    color: var(--secondary-color);
}

.summary-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 25px;
}

.summary-card {
    background: var(--bg-light);
    padding: 25px;
    border-radius: var(--radius);
}

.summary-card h4 {
    font-size: 1.1rem;
    margin-bottom: 15px;
    color: var(--secondary-color);
}

.summary-card ul {
    list-style: disc;
    padding-left: 20px;
}

.summary-card li {
    color: var(--text-light);
    margin-bottom: 8px;
    font-size: 0.95rem;
}

.comparison-screenshot {
    margin-top: 40px;
    text-align: center;
}

.comparison-screenshot img {
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    margin: 0 auto;
}

.comparison-screenshot figcaption {
    margin-top: 12px;
    font-size: 0.85rem;
    color: var(--text-light);
}

/* ==========================================================================
   Advanced Tips Section
   ========================================================================== */
.tips {
    padding: 80px 0;
    background: var(--bg-light);
}

.tips h2 {
    font-size: 2rem;
    margin-bottom: 15px;
}

.tips-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 25px;
    margin-top: 50px;
}

.tip-card {
    background: var(--bg-color);
    padding: 28px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
    text-align: center;
    transition: all var(--transition);
    border: 1px solid var(--border-color);
}

.tip-card:hover {
    transform: translateY(-5px) scale(1.02);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-color);
}

.tip-icon {
    font-size: 2.5rem;
    margin-bottom: 15px;
    display: inline-block;
    animation: float 3s ease-in-out infinite;
}

.tip-card:hover .tip-icon {
    animation-play-state: paused;
}

.tip-card h3 {
    font-size: 1.15rem;
    margin-bottom: 10px;
    color: var(--secondary-color);
    font-weight: 600;
}

.tip-card p {
    color: var(--text-light);
    font-size: 0.9rem;
    margin-bottom: 10px;
}

.tip-card code {
    display: block;
    background: linear-gradient(135deg, var(--bg-light) 0%, #eef2ff 100%);
    padding: 12px;
    border-radius: var(--radius);
    font-size: 0.85rem;
    margin: 12px 0;
    word-break: break-all;
    border: 1px solid var(--border-color);
}

.tip-result {
    font-size: 0.8rem;
    color: #22c55e;
    font-style: italic;
    font-weight: 500;
}

.pro-tip {
    max-width: 800px;
    margin: 50px auto 0;
    background: linear-gradient(135deg, var(--bg-color) 0%, #fef2f2 100%);
    padding: 28px 35px;
    border-radius: var(--radius-lg);
    border-left: 4px solid var(--primary-color);
    box-shadow: var(--shadow);
}

.pro-tip h3 {
    font-size: 1.15rem;
    margin-bottom: 12px;
    color: var(--secondary-color);
    display: flex;
    align-items: center;
    gap: 8px;
}

.pro-tip h3::before {
    content: '💡';
}

.pro-tip p {
    color: var(--text-light);
    font-size: 0.95rem;
    line-height: 1.7;
}

/* ==========================================================================
   Video Section
   ========================================================================== */
.video-section {
    margin-top: 60px;
    text-align: center;
}

.video-section h3 {
    font-size: 1.5rem;
    margin-bottom: 25px;
    color: var(--secondary-color);
}

.video-placeholder {
    max-width: 700px;
    margin: 0 auto;
    background: var(--secondary-color);
    border-radius: var(--radius-xl);
    overflow: hidden;
    position: relative;
    box-shadow: var(--shadow-lg);
}

.video-placeholder::before {
    content: '';
    position: absolute;
    inset: 0;
    background: rgba(0, 0, 0, 0.4);
    transition: var(--transition);
    z-index: 1;
}

.video-placeholder::after {
    content: '▶';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 80px;
    height: 80px;
    background: var(--primary-color);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.8rem;
    color: var(--white);
    z-index: 2;
    transition: var(--transition);
    box-shadow: 0 0 30px rgba(229, 57, 53, 0.5);
}

.video-placeholder:hover::before {
    background: rgba(0, 0, 0, 0.5);
}

.video-placeholder:hover::after {
    transform: translate(-50%, -50%) scale(1.1);
    box-shadow: 0 0 50px rgba(229, 57, 53, 0.7);
}

.video-placeholder img {
    width: 100%;
    height: auto;
    display: block;
}

.video-note {
    padding: 18px;
    color: var(--text-light);
    font-size: 0.95rem;
    background: var(--bg-light);
}

/* ==========================================================================
   Step Images
   ========================================================================== */
.step-image {
    margin-top: 15px;
}

.step-image img {
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}

/* ==========================================================================
   Service Card Images
   ========================================================================== */
.service-img {
    margin-bottom: 15px;
}

/* ==========================================================================
   Stat Source
   ========================================================================== */
.stat-source {
    display: block;
    font-size: 0.75rem;
    color: var(--gray-dark);
    margin-top: 5px;
}

/* ==========================================================================
   Author Section (E-E-A-T)
   ========================================================================== */
.author-section {
    padding: 60px 0;
    background: var(--bg-color);
    border-top: 1px solid var(--border-color);
}

.author-box {
    display: flex;
    gap: 30px;
    align-items: flex-start;
    max-width: 800px;
    margin: 0 auto;
    padding: 35px;
    background: linear-gradient(135deg, var(--bg-light) 0%, #f1f5f9 100%);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.author-box:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
}

.author-avatar {
    flex-shrink: 0;
    border-radius: 50%;
    object-fit: cover;
    border: 4px solid var(--bg-color);
    box-shadow: var(--shadow);
}

.author-info h3 {
    font-size: 1rem;
    color: var(--text-muted);
    margin-bottom: 5px;
    text-transform: uppercase;
    letter-spacing: 1px;
    font-weight: 500;
}

.author-name {
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--secondary-color);
    margin-bottom: 12px;
}

.author-bio {
    color: var(--text-light);
    font-size: 0.95rem;
    line-height: 1.8;
    margin-bottom: 12px;
}

.author-credentials {
    font-size: 0.85rem;
    color: var(--text-muted);
    font-style: italic;
}

@media (max-width: 600px) {
    .author-box {
        flex-direction: column;
        align-items: center;
        text-align: center;
    }
}

/* ==========================================================================
   FAQ Answer Lists
   ========================================================================== */
.faq-answer ul,
.faq-answer ol {
    margin: 10px 0;
    padding-left: 25px;
}

.faq-answer ul {
    list-style: disc;
}

.faq-answer ol {
    list-style: decimal;
}

.faq-answer li {
    margin-bottom: 8px;
    line-height: 1.6;
}

/* Note: a.tag and a.tag:hover styles are defined in the Related Section above */

/* ==========================================================================
   Footer Contact
   ========================================================================== */
.footer-contact {
    margin-top: 15px;
    font-size: 0.85rem;
}

/* ==========================================================================
   Logo with Image
   ========================================================================== */
.logo a {
    display: flex;
    align-items: center;
    gap: 10px;
}

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

/* ==========================================================================
   Mobile Navigation Improvements
   ========================================================================== */
@media (max-width: 900px) {
    .header .container {
        flex-wrap: wrap;
    }

    .nav {
        width: 100%;
        margin-top: 15px;
    }

    .nav-list {
        flex-wrap: wrap;
        justify-content: center;
        gap: 10px 20px;
    }
}

@media (max-width: 480px) {
    .nav-list {
        font-size: 0.8rem;
        gap: 8px 15px;
    }

    .article-meta {
        flex-direction: column;
        align-items: center;
        gap: 10px;
    }

    .comparison-table th,
    .comparison-table td {
        padding: 12px 10px;
        font-size: 0.85rem;
    }

    .timeline {
        padding-left: 20px;
    }

    .timeline-item {
        padding-left: 20px;
    }

    .timeline-item::before {
        left: -24px;
    }
}

/* ==========================================================================
   Keyframe Animations
   ========================================================================== */

/* Used by: .hero::before, .tip-icon */
@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-6px); }
}

/* Used by: .hero, .footer::before */
@keyframes gradient-shift {
    0%, 100% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
}

/* Reduced motion preference */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* ==========================================================================
   Print Styles
   ========================================================================== */
@media print {
    .header,
    .footer,
    .entry-box .btn,
    .breadcrumb,
    .video-section {
        display: none;
    }

    body {
        font-size: 12pt;
        color: #000;
    }

    a {
        color: #000;
        text-decoration: underline;
    }

    .hero {
        background: none;
        color: #000;
        padding: 20px 0;
    }

    .comparison-table {
        box-shadow: none;
        border: 1px solid #ccc;
    }

    .comparison-table th {
        background: #eee;
        color: #000;
    }
}

/* ==========================================================================
   Back to Top Button
   ========================================================================== */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: var(--primary-color);
    color: var(--white);
    border: none;
    border-radius: 50%;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    z-index: 1000;
    box-shadow: var(--shadow-md);
    display: flex;
    align-items: center;
    justify-content: center;
}

.back-to-top:hover {
    background: var(--primary-dark);
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
}

@media (max-width: 768px) {
    .back-to-top {
        bottom: 20px;
        right: 20px;
        width: 44px;
        height: 44px;
    }
}

/* ==========================================================================
   User Reviews Section
   ========================================================================== */
.reviews-section {
    padding: 60px 0;
    background: var(--bg-light);
}

.reviews-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 25px;
    margin: 30px 0;
}

.review-card {
    background: var(--bg-color);
    padding: 25px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.review-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
}

.review-rating {
    color: #fbbf24;
    font-size: 1.2rem;
    margin-bottom: 12px;
}

.review-text {
    font-style: italic;
    color: var(--text-color);
    line-height: 1.7;
    margin-bottom: 15px;
}

.review-author {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    font-size: 0.9rem;
    color: var(--text-light);
}

.reviewer-name {
    font-weight: 600;
    color: var(--secondary-color);
}

.reviews-summary {
    text-align: center;
    margin-top: 30px;
    padding: 20px;
    background: var(--bg-color);
    border-radius: var(--radius);
}

.avg-rating {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary-color);
    display: block;
}

.total-reviews {
    color: var(--text-light);
    font-size: 0.9rem;
}

/* ==========================================================================
   Research Section
   ========================================================================== */
.research-section {
    padding: 60px 0;
}

.research-table-wrapper {
    overflow-x: auto;
    margin: 30px 0;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
}

.research-table {
    width: 100%;
    border-collapse: collapse;
    background: var(--bg-color);
}

.research-table th,
.research-table td {
    padding: 15px 20px;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.research-table th {
    background: var(--secondary-color);
    color: var(--white);
    font-weight: 600;
}

.research-table tbody tr:hover {
    background: rgba(229, 57, 53, 0.05);
}

.highlight-good {
    color: #16a34a;
    font-weight: 600;
}

.research-note {
    text-align: center;
    color: var(--text-light);
    font-size: 0.9rem;
    margin-top: 15px;
}

/* ==========================================================================
   Changelog Section
   ========================================================================== */
.changelog-section {
    padding: 40px 0;
    background: var(--bg-light);
}

.changelog-details {
    background: var(--bg-color);
    border-radius: var(--radius-lg);
    padding: 20px 30px;
}

.changelog-details summary {
    cursor: pointer;
    list-style: none;
}

.changelog-details summary::-webkit-details-marker {
    display: none;
}

.changelog-details summary h2 {
    display: inline-flex;
    align-items: center;
    font-size: 1.2rem;
    margin: 0;
}

.changelog-details summary h2::before {
    content: "▸";
    margin-right: 10px;
    transition: transform 0.2s;
}

.changelog-details[open] summary h2::before {
    transform: rotate(90deg);
}

.changelog-list {
    margin-top: 20px;
    padding-left: 20px;
}

.changelog-list li {
    padding: 8px 0;
    border-bottom: 1px solid var(--border-color);
}

.changelog-list li:last-child {
    border-bottom: none;
}

.changelog-list time {
    font-weight: 600;
    color: var(--primary-color);
    margin-right: 10px;
}

/* ==========================================================================
   Enhanced Author Section
   ========================================================================== */
.author-section h2 {
    text-align: center;
    margin-bottom: 30px;
}

.team-credentials {
    margin-top: 20px;
    display: grid;
    gap: 15px;
}

.credential-item {
    display: flex;
    flex-direction: column;
    gap: 5px;
}

.credential-item strong {
    color: var(--secondary-color);
    font-size: 0.9rem;
}

.credential-item span {
    color: var(--text-light);
    font-size: 0.95rem;
}

.author-link {
    display: inline-block;
    margin-top: 20px;
    color: var(--primary-color);
    font-weight: 600;
    transition: var(--transition);
}

.author-link:hover {
    color: var(--primary-dark);
}

/* ==========================================================================
   About & Policy Pages
   ========================================================================== */
.about-hero,
.policy-hero {
    background: linear-gradient(135deg, var(--secondary-color) 0%, var(--secondary-light) 100%);
    color: var(--white);
    padding: 60px 0;
    text-align: center;
}

.about-hero h1,
.policy-hero h1 {
    color: var(--white);
    margin-bottom: 15px;
}

.last-updated {
    font-size: 0.9rem;
    opacity: 0.8;
    margin-top: 15px;
}

.about-content,
.policy-content {
    padding: 60px 0;
}

.about-grid,
.policy-grid {
    display: flex;
    flex-direction: column;
    gap: 50px;
}

.about-section,
.policy-section {
    max-width: 800px;
    margin: 0 auto;
}

.about-section h2,
.policy-section h2 {
    color: var(--secondary-color);
    margin-bottom: 20px;
    padding-bottom: 10px;
    border-bottom: 2px solid var(--primary-color);
}

.team-list,
.policy-list,
.correction-list,
.feedback-list {
    list-style: none;
    padding: 0;
}

.team-list li,
.policy-list li {
    padding: 15px 0;
    border-bottom: 1px solid var(--border-color);
}

.team-list li:last-child,
.policy-list li:last-child {
    border-bottom: none;
}

.team-list strong,
.policy-list strong {
    display: block;
    color: var(--secondary-color);
    margin-bottom: 5px;
}

.standards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
    margin-top: 25px;
}

.standard-item {
    background: var(--bg-light);
    padding: 25px;
    border-radius: var(--radius);
    text-align: center;
}

.standard-icon {
    width: 50px;
    height: 50px;
    background: var(--primary-color);
    color: var(--white);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 15px;
    font-size: 1.5rem;
}

.standard-item h3 {
    font-size: 1.1rem;
    margin-bottom: 10px;
}

.contact-info {
    background: var(--bg-light);
    padding: 25px;
    border-radius: var(--radius);
    margin-top: 20px;
}

.contact-info p {
    margin: 10px 0;
}

.verification-steps {
    margin-top: 25px;
}

.step-item {
    display: flex;
    gap: 20px;
    padding: 20px 0;
    border-bottom: 1px solid var(--border-color);
}

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

.step-item .step-number {
    width: 40px;
    height: 40px;
    background: var(--primary-color);
    color: var(--white);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    flex-shrink: 0;
}

.step-item .step-content h3 {
    font-size: 1rem;
    margin-bottom: 5px;
}

.update-table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 20px;
}

.update-table th,
.update-table td {
    padding: 12px 15px;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.update-table th {
    background: var(--secondary-color);
    color: var(--white);
}

.update-table tbody tr:hover {
    background: var(--bg-light);
}

.correction-list li,
.feedback-list li {
    padding: 10px 0;
}