/* ============================================
   抖音揭秘 - 原创样式表
   品牌色系：深紫黑 + 活力橙 + 科技青绿
   ============================================ */

/* === CSS Variables === */
:root {
    --primary: #1A0E2E;
    --secondary: #FF6B35;
    --accent: #00D4AA;
    --bg-dark: #0D0B14;
    --bg-card: #1E1A2E;
    --bg-card-hover: #2A2440;
    --text-light: #E8E6F0;
    --text-muted: #9B97A8;
    --text-white: #FFFFFF;
    --gradient-main: linear-gradient(135deg, #FF6B35 0%, #00D4AA 100%);
    --gradient-dark: linear-gradient(180deg, #0D0B14 0%, #1A0E2E 100%);
    --gradient-card: linear-gradient(145deg, #1E1A2E 0%, #15112A 100%);
    --shadow-sm: 0 2px 8px rgba(0,0,0,0.3);
    --shadow-md: 0 4px 20px rgba(0,0,0,0.4);
    --shadow-lg: 0 8px 40px rgba(0,0,0,0.5);
    --shadow-glow: 0 0 20px rgba(255,107,53,0.3);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --radius-xl: 30px;
    --transition: all 0.3s ease;
    --font-main: 'PingFang SC', 'Microsoft YaHei', 'Hiragino Sans GB', sans-serif;
}

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-main);
    background: var(--bg-dark);
    color: var(--text-light);
    line-height: 1.7;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

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

a:hover {
    color: var(--accent);
}

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

ul, ol {
    list-style: none;
}

.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 20px;
}

.section-padding {
    padding: 80px 0;
}

/* === Typography === */
h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.3;
    color: var(--text-white);
}

h1 { font-size: 2.8rem; }
h2 { font-size: 2.2rem; }
h3 { font-size: 1.6rem; }
h4 { font-size: 1.3rem; }
h5 { font-size: 1.1rem; }
h6 { font-size: 1rem; }

.section-title {
    text-align: center;
    margin-bottom: 50px;
    position: relative;
}

.section-title h2 {
    display: inline-block;
    position: relative;
    padding-bottom: 15px;
}

.section-title h2::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 3px;
    background: var(--gradient-main);
    border-radius: 2px;
}

.section-title p {
    color: var(--text-muted);
    margin-top: 15px;
    font-size: 1.05rem;
}

/* === Buttons === */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 28px;
    border-radius: var(--radius-xl);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    border: none;
    gap: 8px;
}

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

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 0 30px rgba(255,107,53,0.5);
    color: var(--text-white);
}

.btn-outline {
    background: transparent;
    color: var(--secondary);
    border: 2px solid var(--secondary);
}

.btn-outline:hover {
    background: var(--secondary);
    color: var(--text-white);
    transform: translateY(-2px);
}

.btn-accent {
    background: var(--accent);
    color: var(--primary);
    font-weight: 700;
}

.btn-accent:hover {
    background: #00E8BB;
    transform: translateY(-2px);
    color: var(--primary);
}

/* === Header & Navigation === */
.site-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(13, 11, 20, 0.92);
    backdrop-filter: blur(15px);
    -webkit-backdrop-filter: blur(15px);
    border-bottom: 1px solid rgba(255,255,255,0.06);
    transition: var(--transition);
}

.site-header.scrolled {
    box-shadow: var(--shadow-md);
}

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 70px;
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 20px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
}

.logo img {
    height: 42px;
    width: auto;
}

.logo-text {
    font-size: 1.4rem;
    font-weight: 800;
    color: var(--text-white);
    letter-spacing: 1px;
}

.logo-text span {
    background: var(--gradient-main);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.main-nav {
    display: flex;
    align-items: center;
    gap: 5px;
}

.main-nav a {
    color: var(--text-light);
    padding: 8px 16px;
    border-radius: var(--radius-sm);
    font-size: 0.95rem;
    font-weight: 500;
    position: relative;
    transition: var(--transition);
}

.main-nav a:hover,
.main-nav a.active {
    color: var(--secondary);
    background: rgba(255,107,53,0.08);
}

.main-nav a.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 20px;
    height: 2px;
    background: var(--secondary);
    border-radius: 1px;
}

.mobile-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
    padding: 5px;
}

.mobile-toggle span {
    width: 24px;
    height: 2px;
    background: var(--text-light);
    border-radius: 2px;
    transition: var(--transition);
}

/* === Search Bar === */
.search-bar-wrapper {
    background: rgba(30, 26, 46, 0.8);
    border-bottom: 1px solid rgba(255,255,255,0.04);
    padding: 12px 0;
    margin-top: 70px;
}

.search-bar {
    max-width: 680px;
    margin: 0 auto;
    position: relative;
    display: flex;
    align-items: center;
}

.search-bar input {
    width: 100%;
    padding: 12px 50px 12px 20px;
    background: rgba(13, 11, 20, 0.7);
    border: 1px solid rgba(255,255,255,0.1);
    border-radius: var(--radius-xl);
    color: var(--text-light);
    font-size: 0.95rem;
    outline: none;
    transition: var(--transition);
    font-family: var(--font-main);
}

.search-bar input:focus {
    border-color: var(--secondary);
    box-shadow: 0 0 15px rgba(255,107,53,0.15);
}

.search-bar input::placeholder {
    color: var(--text-muted);
}

.search-bar button {
    position: absolute;
    right: 5px;
    top: 50%;
    transform: translateY(-50%);
    background: var(--gradient-main);
    border: none;
    width: 38px;
    height: 38px;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
}

.search-bar button:hover {
    transform: translateY(-50%) scale(1.05);
}

.search-bar button svg {
    width: 18px;
    height: 18px;
    fill: white;
}

/* === Hero Section === */
.hero {
    position: relative;
    min-height: 75vh;
    display: flex;
    align-items: center;
    overflow: hidden;
    background: var(--bg-dark);
}

.hero-bg {
    position: absolute;
    inset: 0;
    z-index: 1;
}

.hero-bg img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    opacity: 0.45;
}

.hero-bg::after {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(180deg, rgba(13,11,20,0.3) 0%, rgba(13,11,20,0.85) 80%, rgba(13,11,20,1) 100%);
}

.hero-content {
    position: relative;
    z-index: 2;
    max-width: 750px;
    padding: 40px 0;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: rgba(255,107,53,0.12);
    border: 1px solid rgba(255,107,53,0.3);
    padding: 6px 16px;
    border-radius: var(--radius-xl);
    font-size: 0.85rem;
    color: var(--secondary);
    margin-bottom: 20px;
}

.hero h1 {
    font-size: 3.2rem;
    font-weight: 900;
    margin-bottom: 20px;
    line-height: 1.2;
}

.hero h1 .highlight {
    background: var(--gradient-main);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero p {
    font-size: 1.15rem;
    color: var(--text-muted);
    margin-bottom: 30px;
    max-width: 600px;
}

.hero-stats {
    display: flex;
    gap: 40px;
    margin-top: 40px;
}

.hero-stat {
    text-align: center;
}

.hero-stat .num {
    font-size: 2rem;
    font-weight: 800;
    background: var(--gradient-main);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-stat .label {
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-top: 4px;
}

.hero-btns {
    display: flex;
    gap: 15px;
    flex-wrap: wrap;
}

/* === Video Cards Grid === */
.video-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.video-card {
    background: var(--gradient-card);
    border-radius: var(--radius-md);
    overflow: hidden;
    border: 1px solid rgba(255,255,255,0.06);
    transition: var(--transition);
    cursor: pointer;
}

.video-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-lg);
    border-color: rgba(255,107,53,0.2);
}

.video-thumb {
    position: relative;
    aspect-ratio: 16/9;
    overflow: hidden;
}

.video-thumb img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s ease;
}

.video-card:hover .video-thumb img {
    transform: scale(1.08);
}

.video-play-btn {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%) scale(0.8);
    width: 56px;
    height: 56px;
    background: rgba(255,107,53,0.9);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: var(--transition);
    box-shadow: 0 0 30px rgba(255,107,53,0.4);
}

.video-card:hover .video-play-btn {
    opacity: 1;
    transform: translate(-50%, -50%) scale(1);
}

.video-play-btn svg {
    width: 22px;
    height: 22px;
    fill: white;
    margin-left: 3px;
}

.video-duration {
    position: absolute;
    bottom: 8px;
    right: 8px;
    background: rgba(0,0,0,0.75);
    color: white;
    padding: 2px 8px;
    border-radius: 4px;
    font-size: 0.8rem;
    font-weight: 600;
}

.video-info {
    padding: 16px;
}

.video-info h4 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 8px;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
    line-height: 1.4;
}

.video-meta {
    display: flex;
    align-items: center;
    gap: 15px;
    color: var(--text-muted);
    font-size: 0.82rem;
}

.video-meta span {
    display: flex;
    align-items: center;
    gap: 4px;
}

.video-tags {
    display: flex;
    gap: 6px;
    margin-top: 10px;
    flex-wrap: wrap;
}

.video-tag {
    background: rgba(255,107,53,0.1);
    color: var(--secondary);
    padding: 3px 10px;
    border-radius: var(--radius-xl);
    font-size: 0.75rem;
    border: 1px solid rgba(255,107,53,0.15);
}

/* === Service Cards === */
.service-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 28px;
}

.service-card {
    background: var(--gradient-card);
    border-radius: var(--radius-md);
    padding: 35px 28px;
    border: 1px solid rgba(255,255,255,0.06);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.service-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: var(--gradient-main);
    transform: scaleX(0);
    transition: transform 0.4s ease;
}

.service-card:hover::before {
    transform: scaleX(1);
}

.service-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-md);
    border-color: rgba(255,107,53,0.15);
}

.service-icon {
    width: 60px;
    height: 60px;
    background: rgba(255,107,53,0.1);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 20px;
    font-size: 1.8rem;
}

.service-card h4 {
    margin-bottom: 12px;
}

.service-card p {
    color: var(--text-muted);
    font-size: 0.95rem;
    line-height: 1.7;
}

/* === Gallery Section === */
.gallery-grid {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 16px;
}

.gallery-item {
    position: relative;
    border-radius: var(--radius-md);
    overflow: hidden;
    aspect-ratio: 3/4;
    cursor: pointer;
}

.gallery-item img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s ease;
}

.gallery-item:hover img {
    transform: scale(1.1);
}

.gallery-overlay {
    position: absolute;
    inset: 0;
    background: linear-gradient(180deg, transparent 40%, rgba(13,11,20,0.85) 100%);
    display: flex;
    flex-direction: column;
    justify-content: flex-end;
    padding: 16px;
    opacity: 0;
    transition: var(--transition);
}

.gallery-item:hover .gallery-overlay {
    opacity: 1;
}

.gallery-overlay h5 {
    font-size: 0.95rem;
    margin-bottom: 4px;
}

.gallery-overlay span {
    font-size: 0.8rem;
    color: var(--text-muted);
}

/* === Expert Section === */
.expert-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 28px;
}

.expert-card {
    background: var(--gradient-card);
    border-radius: var(--radius-md);
    padding: 30px 20px;
    text-align: center;
    border: 1px solid rgba(255,255,255,0.06);
    transition: var(--transition);
}

.expert-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-md);
    border-color: rgba(0,212,170,0.2);
}

.expert-avatar {
    width: 100px;
    height: 100px;
    border-radius: 50%;
    overflow: hidden;
    margin: 0 auto 18px;
    border: 3px solid rgba(255,107,53,0.3);
    transition: var(--transition);
}

.expert-card:hover .expert-avatar {
    border-color: var(--secondary);
}

.expert-avatar img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.expert-card h4 {
    font-size: 1.1rem;
    margin-bottom: 6px;
}

.expert-role {
    color: var(--secondary);
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 10px;
}

.expert-desc {
    color: var(--text-muted);
    font-size: 0.88rem;
    margin-bottom: 16px;
    line-height: 1.6;
}

.expert-btns {
    display: flex;
    gap: 8px;
    justify-content: center;
}

.expert-btns .btn {
    padding: 8px 16px;
    font-size: 0.82rem;
}

/* === Brand Wall === */
.brand-wall {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 30px;
    align-items: center;
}

.brand-logo {
    background: var(--bg-card);
    padding: 20px 35px;
    border-radius: var(--radius-sm);
    border: 1px solid rgba(255,255,255,0.06);
    color: var(--text-muted);
    font-size: 1.1rem;
    font-weight: 700;
    transition: var(--transition);
    letter-spacing: 1px;
}

.brand-logo:hover {
    border-color: rgba(255,107,53,0.2);
    color: var(--text-light);
    transform: translateY(-3px);
}

/* === Reviews Section === */
.review-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
}

.review-card {
    background: var(--gradient-card);
    border-radius: var(--radius-md);
    padding: 28px;
    border: 1px solid rgba(255,255,255,0.06);
    transition: var(--transition);
}

.review-card:hover {
    border-color: rgba(0,212,170,0.15);
}

.review-stars {
    color: #FFB800;
    font-size: 1rem;
    margin-bottom: 12px;
    letter-spacing: 2px;
}

.review-text {
    color: var(--text-light);
    font-size: 0.95rem;
    line-height: 1.7;
    margin-bottom: 16px;
    font-style: italic;
}

.review-author {
    display: flex;
    align-items: center;
    gap: 12px;
}

.review-author-avatar {
    width: 42px;
    height: 42px;
    border-radius: 50%;
    background: var(--gradient-main);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-weight: 700;
    font-size: 1rem;
}

.review-author-info .name {
    font-weight: 600;
    font-size: 0.92rem;
    color: var(--text-white);
}

.review-author-info .date {
    font-size: 0.8rem;
    color: var(--text-muted);
}

/* === FAQ Section === */
.faq-list {
    max-width: 850px;
    margin: 0 auto;
}

.faq-item {
    background: var(--gradient-card);
    border-radius: var(--radius-md);
    margin-bottom: 14px;
    border: 1px solid rgba(255,255,255,0.06);
    overflow: hidden;
    transition: var(--transition);
}

.faq-item:hover {
    border-color: rgba(255,107,53,0.15);
}

.faq-question {
    padding: 20px 24px;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-weight: 600;
    color: var(--text-white);
    font-size: 1.02rem;
    transition: var(--transition);
}

.faq-question:hover {
    color: var(--secondary);
}

.faq-toggle {
    width: 28px;
    height: 28px;
    background: rgba(255,107,53,0.1);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
    flex-shrink: 0;
    margin-left: 15px;
}

.faq-item.active .faq-toggle {
    background: var(--secondary);
    transform: rotate(180deg);
}

.faq-toggle svg {
    width: 14px;
    height: 14px;
    fill: var(--secondary);
}

.faq-item.active .faq-toggle svg {
    fill: white;
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease;
}

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

.faq-answer-inner {
    padding: 0 24px 20px;
    color: var(--text-muted);
    font-size: 0.95rem;
    line-height: 1.8;
}

/* === Contact Section === */
.contact-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 28px;
}

.contact-card {
    background: var(--gradient-card);
    border-radius: var(--radius-md);
    padding: 30px;
    text-align: center;
    border: 1px solid rgba(255,255,255,0.06);
    transition: var(--transition);
}

.contact-card:hover {
    border-color: rgba(255,107,53,0.15);
    transform: translateY(-3px);
}

.contact-icon {
    width: 55px;
    height: 55px;
    background: rgba(255,107,53,0.1);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 16px;
    font-size: 1.5rem;
}

.contact-card h5 {
    margin-bottom: 8px;
}

.contact-card p {
    color: var(--text-muted);
    font-size: 0.9rem;
}

/* === Footer === */
.site-footer {
    background: linear-gradient(180deg, var(--bg-dark) 0%, #080612 100%);
    border-top: 1px solid rgba(255,255,255,0.06);
    padding: 60px 0 30px;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1.5fr;
    gap: 40px;
    margin-bottom: 40px;
}

.footer-brand .logo {
    margin-bottom: 16px;
}

.footer-brand p {
    color: var(--text-muted);
    font-size: 0.9rem;
    line-height: 1.7;
    margin-bottom: 16px;
}

.footer-title {
    font-size: 1.05rem;
    font-weight: 700;
    margin-bottom: 20px;
    color: var(--text-white);
}

.footer-links a {
    display: block;
    color: var(--text-muted);
    padding: 5px 0;
    font-size: 0.9rem;
    transition: var(--transition);
}

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

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

.footer-qr-item {
    text-align: center;
}

.footer-qr-item img {
    width: 110px;
    height: 110px;
    border-radius: var(--radius-sm);
    margin-bottom: 8px;
    border: 1px solid rgba(255,255,255,0.1);
}

.footer-qr-item span {
    font-size: 0.8rem;
    color: var(--text-muted);
}

.footer-bottom {
    border-top: 1px solid rgba(255,255,255,0.06);
    padding-top: 25px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 15px;
}

.footer-bottom p {
    color: var(--text-muted);
    font-size: 0.85rem;
}

.social-links {
    display: flex;
    gap: 12px;
}

.social-link {
    width: 38px;
    height: 38px;
    background: var(--bg-card);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-muted);
    font-size: 0.9rem;
    transition: var(--transition);
    border: 1px solid rgba(255,255,255,0.06);
}

.social-link:hover {
    background: var(--secondary);
    color: white;
    border-color: var(--secondary);
    transform: translateY(-3px);
}

/* === Community Features === */
.community-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.community-card {
    background: var(--gradient-card);
    border-radius: var(--radius-md);
    padding: 28px;
    border: 1px solid rgba(255,255,255,0.06);
    transition: var(--transition);
    text-align: center;
}

.community-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-md);
    border-color: rgba(0,212,170,0.2);
}

.community-icon {
    width: 70px;
    height: 70px;
    background: rgba(0,212,170,0.1);
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 18px;
    font-size: 2rem;
}

.community-card h4 {
    margin-bottom: 10px;
}

.community-card p {
    color: var(--text-muted);
    font-size: 0.92rem;
}

/* === AI Section === */
.ai-features {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 30px;
    align-items: center;
}

.ai-feature-list {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.ai-feature-item {
    display: flex;
    gap: 16px;
    align-items: flex-start;
    padding: 20px;
    background: var(--gradient-card);
    border-radius: var(--radius-md);
    border: 1px solid rgba(255,255,255,0.06);
    transition: var(--transition);
}

.ai-feature-item:hover {
    border-color: rgba(0,212,170,0.2);
    transform: translateX(5px);
}

.ai-feature-icon {
    width: 48px;
    height: 48px;
    background: rgba(0,212,170,0.1);
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.4rem;
    flex-shrink: 0;
}

.ai-feature-text h5 {
    margin-bottom: 6px;
}

.ai-feature-text p {
    color: var(--text-muted);
    font-size: 0.9rem;
}

.ai-visual {
    position: relative;
    border-radius: var(--radius-lg);
    overflow: hidden;
}

.ai-visual img {
    width: 100%;
    border-radius: var(--radius-lg);
}

/* === How-To Section === */
.howto-steps {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
    margin-top: 40px;
}

.howto-step {
    text-align: center;
    position: relative;
}

.howto-num {
    width: 50px;
    height: 50px;
    background: var(--gradient-main);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.3rem;
    font-weight: 800;
    color: white;
    margin: 0 auto 16px;
}

.howto-step h5 {
    margin-bottom: 8px;
}

.howto-step p {
    color: var(--text-muted);
    font-size: 0.88rem;
}

/* === Breadcrumb === */
.breadcrumb {
    padding: 15px 0;
    margin-top: 70px;
}

.breadcrumb-list {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.88rem;
}

.breadcrumb-list a {
    color: var(--text-muted);
}

.breadcrumb-list a:hover {
    color: var(--secondary);
}

.breadcrumb-list .separator {
    color: var(--text-muted);
}

.breadcrumb-list .current {
    color: var(--secondary);
}

/* === Inner Page Styles === */
.page-hero {
    padding: 50px 0 40px;
    text-align: center;
    background: var(--gradient-dark);
}

.page-hero h1 {
    font-size: 2.4rem;
    margin-bottom: 15px;
}

.page-hero p {
    color: var(--text-muted);
    font-size: 1.05rem;
    max-width: 650px;
    margin: 0 auto;
}

.content-section {
    padding: 50px 0;
}

.content-text {
    max-width: 900px;
    margin: 0 auto;
    line-height: 1.9;
    color: var(--text-light);
    font-size: 1rem;
}

.content-text p {
    margin-bottom: 20px;
}

.content-text h2, .content-text h3 {
    margin: 35px 0 15px;
}

/* === Lazy Load === */
.lazy-img {
    opacity: 0;
    transition: opacity 0.5s ease;
}

.lazy-img.loaded {
    opacity: 1;
}

/* === Animations === */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.animate-in {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.animate-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* === Responsive === */
@media (max-width: 1024px) {
    .video-grid {
        grid-template-columns: repeat(3, 1fr);
    }
    .expert-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .footer-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .ai-features {
        grid-template-columns: 1fr;
    }
    .howto-steps {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    html { font-size: 15px; }
    
    .mobile-toggle {
        display: flex;
    }
    
    .main-nav {
        position: fixed;
        top: 70px;
        left: 0;
        right: 0;
        background: rgba(13, 11, 20, 0.98);
        flex-direction: column;
        padding: 20px;
        gap: 5px;
        transform: translateY(-120%);
        transition: transform 0.3s ease;
        border-bottom: 1px solid rgba(255,255,255,0.06);
    }
    
    .main-nav.open {
        transform: translateY(0);
    }
    
    .main-nav a {
        padding: 12px 16px;
        width: 100%;
    }
    
    h1 { font-size: 2rem; }
    h2 { font-size: 1.7rem; }
    
    .hero { min-height: 60vh; }
    .hero h1 { font-size: 2.2rem; }
    .hero-stats { gap: 20px; }
    
    .video-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 16px;
    }
    
    .service-grid,
    .community-grid,
    .contact-grid {
        grid-template-columns: 1fr;
    }
    
    .gallery-grid {
        grid-template-columns: repeat(3, 1fr);
    }
    
    .expert-grid {
        grid-template-columns: 1fr;
    }
    
    .review-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-grid {
        grid-template-columns: 1fr;
        gap: 30px;
    }
    
    .footer-bottom {
        flex-direction: column;
        text-align: center;
    }
    
    .section-padding {
        padding: 50px 0;
    }
    
    .howto-steps {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .video-grid {
        grid-template-columns: 1fr;
    }
    
    .gallery-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .hero-stats {
        flex-direction: column;
        gap: 15px;
    }
    
    .hero-btns {
        flex-direction: column;
    }
    
    .hero-btns .btn {
        width: 100%;
    }
}

/* === Share Buttons === */
.share-bar {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 20px 0;
}

.share-bar span {
    color: var(--text-muted);
    font-size: 0.9rem;
}

.share-btn {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 0.85rem;
    transition: var(--transition);
    cursor: pointer;
}

.share-btn.wechat { background: #07C160; }
.share-btn.weibo { background: #E6162D; }
.share-btn.douyin { background: #161823; border: 1px solid #333; }
.share-btn.bilibili { background: #00A1D6; }

.share-btn:hover {
    transform: translateY(-3px) scale(1.1);
}

/* === Back to Top === */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 46px;
    height: 46px;
    background: var(--gradient-main);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
    z-index: 999;
    box-shadow: var(--shadow-glow);
    border: none;
}

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

.back-to-top:hover {
    transform: translateY(-3px);
}

.back-to-top svg {
    width: 20px;
    height: 20px;
    fill: white;
}

/* === MCP Frontend Placeholder === */
.mcp-widget {
    background: var(--bg-card);
    border-radius: var(--radius-md);
    padding: 20px;
    border: 1px solid rgba(255,255,255,0.06);
    text-align: center;
    margin-top: 20px;
}

.mcp-widget p {
    color: var(--text-muted);
    font-size: 0.85rem;
}

/* === EEAT Credentials Section === */
.credentials-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.credential-item {
    background: var(--gradient-card);
    border: 1px solid rgba(255,255,255,0.06);
    border-radius: var(--radius-md);
    padding: 30px 24px;
    text-align: center;
    transition: var(--transition);
}

.credential-item:hover {
    transform: translateY(-4px);
    border-color: rgba(255,107,53,0.3);
    box-shadow: var(--shadow-glow);
}

.credential-icon {
    font-size: 2.5rem;
    margin-bottom: 16px;
}

.credential-item h5 {
    color: var(--text-white);
    font-size: 1.05rem;
    margin-bottom: 10px;
    font-weight: 600;
}

.credential-item p {
    color: var(--text-muted);
    font-size: 0.9rem;
    line-height: 1.6;
}

@media (max-width: 768px) {
    .credentials-grid {
        grid-template-columns: 1fr;
        gap: 16px;
    }
    .credential-item {
        padding: 24px 20px;
    }
}

@media (min-width: 769px) and (max-width: 1024px) {
    .credentials-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

/* === Logo Image Styling === */
.site-logo-img {
    border-radius: 6px;
    object-fit: contain;
}