/* ========================================
   极简黑白专业软件下载门户 - style.css
   Template 008
======================================== */

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --black: #0a0a0a;
    --dark: #1a1a1a;
    --gray-900: #262626;
    --gray-800: #404040;
    --gray-600: #737373;
    --gray-400: #a3a3a3;
    --gray-200: #e5e5e5;
    --gray-100: #f5f5f5;
    --gray-50: #fafafa;
    --white: #ffffff;
    --accent: #0a0a0a;
    --radius: 2px;
    --radius-lg: 4px;
    --transition: all 0.2s ease;
    --container: 1280px;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Noto Sans SC', 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    font-size: 15px;
    line-height: 1.7;
    color: var(--dark);
    background: var(--white);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

.container {
    max-width: var(--container);
    margin: 0 auto;
    padding: 0 24px;
}

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

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

ul {
    list-style: none;
}

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

/* ========================================
   顶部导航
======================================== */
.site-header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(255,255,255,0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--gray-200);
}

.header-container {
    max-width: var(--container);
    margin: 0 auto;
    padding: 0 24px;
    height: 72px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.brand {
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 700;
    font-size: 20px;
    color: var(--black);
}

.brand-mark {
    font-size: 22px;
}

.main-nav ul {
    display: flex;
    gap: 32px;
}

.main-nav a {
    font-size: 14px;
    font-weight: 500;
    color: var(--gray-600);
    position: relative;
    padding: 4px 0;
}

.main-nav a:hover {
    color: var(--black);
}

.main-nav a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 1px;
    background: var(--black);
    transition: var(--transition);
}

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

.header-actions {
    display: flex;
    align-items: center;
    gap: 16px;
}

.header-phone {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 10px 20px;
    background: var(--black);
    color: var(--white);
    font-size: 14px;
    font-weight: 500;
    border-radius: var(--radius);
}

.header-phone:hover {
    background: var(--gray-900);
}

.mobile-toggle {
    display: none;
    flex-direction: column;
    gap: 4px;
    padding: 8px;
}

.mobile-toggle span {
    width: 22px;
    height: 2px;
    background: var(--black);
    transition: var(--transition);
}

/* ========================================
   按钮样式
======================================== */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 14px 28px;
    font-size: 15px;
    font-weight: 500;
    border-radius: var(--radius);
    transition: var(--transition);
    cursor: pointer;
    border: 1px solid transparent;
}

.btn-primary {
    background: var(--black);
    color: var(--white);
}

.btn-primary:hover {
    background: var(--gray-900);
    transform: translateY(-1px);
}

.btn-outline {
    background: transparent;
    color: var(--black);
    border-color: var(--black);
}

.btn-outline:hover {
    background: var(--black);
    color: var(--white);
}

.btn.full-width {
    width: 100%;
    justify-content: center;
}

/* ========================================
   Hero 主视觉
======================================== */
.hero {
    padding: 80px 0 100px;
    border-bottom: 1px solid var(--gray-200);
}

.hero-container {
    max-width: var(--container);
    margin: 0 auto;
    padding: 0 24px;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.hero-badge {
    display: inline-block;
    padding: 6px 14px;
    background: var(--gray-100);
    font-size: 13px;
    font-weight: 500;
    letter-spacing: 1px;
    margin-bottom: 24px;
    border-radius: var(--radius);
}

.hero-title {
    font-size: 48px;
    font-weight: 700;
    line-height: 1.2;
    letter-spacing: -0.5px;
    margin-bottom: 24px;
}

.hero-subtitle {
    font-size: 17px;
    color: var(--gray-600);
    line-height: 1.8;
    margin-bottom: 40px;
    max-width: 540px;
}

.hero-actions {
    display: flex;
    gap: 16px;
    margin-bottom: 40px;
}

.hero-contact {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 14px;
    color: var(--gray-600);
}

.hero-contact a {
    font-size: 20px;
    font-weight: 700;
    color: var(--black);
}

.hero-image img {
    width: 100%;
    border-radius: var(--radius-lg);
    box-shadow: 0 20px 60px rgba(0,0,0,0.1);
}

/* ========================================
   通用区块头部
======================================== */
.section-header {
    margin-bottom: 48px;
    display: flex;
    flex-direction: column;
    align-items: flex-start;
}

.section-index {
    font-family: 'Inter', monospace;
    font-size: 14px;
    font-weight: 600;
    color: var(--gray-400);
    letter-spacing: 2px;
    margin-bottom: 12px;
}

.section-header h2 {
    font-size: 36px;
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 16px;
}

.section-desc {
    font-size: 16px;
    color: var(--gray-600);
    max-width: 600px;
}

/* ========================================
   平台分类
======================================== */
.platforms-section {
    padding: 100px 0;
}

.platforms-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.platform-card {
    padding: 32px;
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-lg);
    transition: var(--transition);
    display: flex;
    flex-direction: column;
}

.platform-card:hover {
    border-color: var(--black);
    box-shadow: 0 8px 30px rgba(0,0,0,0.08);
    transform: translateY(-2px);
}

.platform-header {
    display: flex;
    align-items: center;
    gap: 16px;
    margin-bottom: 20px;
}

.platform-logo {
    width: 48px;
    height: 48px;
    border-radius: var(--radius);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 18px;
    color: var(--white);
    background: var(--black);
}

.platform-logo.more {
    background: var(--gray-100);
    color: var(--gray-600);
    font-size: 24px;
}

.platform-header h3 {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 2px;
}

.platform-header p {
    font-size: 13px;
    color: var(--gray-600);
}

.platform-devices {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 16px;
}

.device-tag {
    padding: 4px 10px;
    background: var(--gray-100);
    font-size: 12px;
    font-weight: 500;
    color: var(--gray-800);
    border-radius: var(--radius);
}

.platform-desc {
    font-size: 14px;
    color: var(--gray-600);
    line-height: 1.7;
    margin-bottom: 24px;
    flex-grow: 1;
}

.platform-actions {
    display: flex;
    gap: 10px;
    margin-bottom: 20px;
}

.platform-btn {
    flex: 1;
    text-align: center;
    padding: 10px 16px;
    font-size: 13px;
    font-weight: 500;
    background: var(--black);
    color: var(--white);
    border-radius: var(--radius);
    transition: var(--transition);
}

.platform-btn:hover {
    background: var(--gray-900);
}

.platform-btn.secondary {
    background: transparent;
    color: var(--black);
    border: 1px solid var(--gray-200);
}

.platform-btn.secondary:hover {
    border-color: var(--black);
    background: var(--gray-50);
}

.security-note {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 10px 12px;
    background: var(--gray-50);
    font-size: 12px;
    color: var(--gray-600);
    border-radius: var(--radius);
}

/* ========================================
   下载中心
======================================== */
.downloads-section {
    padding: 100px 0;
    background: var(--gray-50);
}

.device-tabs {
    display: flex;
    gap: 4px;
    margin-bottom: 32px;
    border-bottom: 1px solid var(--gray-200);
    overflow-x: auto;
    padding-bottom: 0;
}

.device-tab {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 16px 24px;
    font-size: 14px;
    font-weight: 500;
    color: var(--gray-600);
    border-bottom: 2px solid transparent;
    margin-bottom: -1px;
    white-space: nowrap;
    transition: var(--transition);
}

.device-tab:hover {
    color: var(--black);
}

.device-tab.active {
    color: var(--black);
    border-bottom-color: var(--black);
}

.download-content {
    display: none;
}

.download-content.active {
    display: block;
}

.device-intro {
    margin-bottom: 28px;
    padding-bottom: 28px;
    border-bottom: 1px solid var(--gray-200);
}

.device-intro h3 {
    font-size: 22px;
    font-weight: 600;
    margin-bottom: 8px;
}

.device-intro p {
    font-size: 15px;
    color: var(--gray-600);
}

.download-list {
    display: flex;
    flex-direction: column;
    gap: 1px;
    background: var(--gray-200);
    border-radius: var(--radius-lg);
    overflow: hidden;
    margin-bottom: 24px;
}

.download-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 20px 24px;
    background: var(--white);
    gap: 20px;
}

.download-info h4 {
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 4px;
}

.download-info p {
    font-size: 13px;
    color: var(--gray-600);
}

.download-actions {
    display: flex;
    align-items: center;
    gap: 16px;
    flex-shrink: 0;
}

.source-badge {
    padding: 4px 10px;
    background: var(--black);
    color: var(--white);
    font-size: 12px;
    font-weight: 500;
    border-radius: var(--radius);
}

.download-btn {
    padding: 10px 20px;
    background: var(--black);
    color: var(--white);
    font-size: 13px;
    font-weight: 500;
    border-radius: var(--radius);
}

.download-btn:hover {
    background: var(--gray-900);
}

.download-notice {
    padding: 20px 24px;
    background: var(--white);
    border-left: 3px solid var(--black);
    font-size: 14px;
    color: var(--gray-800);
    border-radius: var(--radius);
}

.download-notice strong {
    color: var(--black);
}

/* ========================================
   平台功能
======================================== */
.features-section {
    padding: 100px 0;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
    margin-bottom: 32px;
}

.feature-card {
    padding: 32px;
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-lg);
    transition: var(--transition);
}

.feature-card:hover {
    border-color: var(--black);
}

.feature-icon {
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--gray-100);
    border-radius: var(--radius);
    margin-bottom: 20px;
    color: var(--black);
}

.feature-card h3 {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 12px;
}

.feature-card p {
    font-size: 14px;
    color: var(--gray-600);
    line-height: 1.7;
}

.risk-warning {
    padding: 24px;
    background: var(--gray-100);
    border-radius: var(--radius-lg);
    font-size: 14px;
    color: var(--gray-800);
    line-height: 1.8;
}

.risk-warning strong {
    color: var(--black);
}

/* ========================================
   使用流程
======================================== */
.guide-section {
    padding: 100px 0;
    background: var(--gray-50);
}

.guide-steps {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 0;
    position: relative;
}

.step-item {
    padding: 32px;
    background: var(--white);
    border: 1px solid var(--gray-200);
    position: relative;
}

.step-number {
    font-family: 'Inter', monospace;
    font-size: 48px;
    font-weight: 700;
    color: var(--gray-200);
    line-height: 1;
    margin-bottom: 20px;
}

.step-content h3 {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 12px;
}

.step-content p {
    font-size: 14px;
    color: var(--gray-600);
    line-height: 1.7;
    margin-bottom: 16px;
}

.step-content ul {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.step-content li {
    font-size: 13px;
    color: var(--gray-600);
    padding-left: 18px;
    position: relative;
}

.step-content li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 9px;
    width: 6px;
    height: 6px;
    background: var(--black);
    border-radius: 50%;
}

/* ========================================
   安全说明
======================================== */
.security-section {
    padding: 100px 0;
}

.security-card {
    padding: 48px;
    background: var(--black);
    color: var(--white);
    border-radius: var(--radius-lg);
}

.security-header {
    display: flex;
    align-items: center;
    gap: 16px;
    margin-bottom: 40px;
    padding-bottom: 32px;
    border-bottom: 1px solid var(--gray-800);
}

.security-header h2 {
    font-size: 28px;
    font-weight: 700;
}

.security-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 28px;
}

.security-item {
    display: flex;
    gap: 16px;
}

.security-icon {
    flex-shrink: 0;
    width: 28px;
    height: 28px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(255,255,255,0.1);
    border-radius: 50%;
    margin-top: 2px;
}

.security-item h4 {
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 6px;
}

.security-item p {
    font-size: 14px;
    color: var(--gray-400);
    line-height: 1.7;
}

/* ========================================
   资讯列表 - 硬性规范
======================================== */
.news-section {
    padding: 100px 0;
    background: var(--gray-50);
}

ul.article-cards {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
    gap: 24px;
    list-style: none;
    margin: 0;
    padding: 0;
    width: 100%;
    box-sizing: border-box;
}

ul.article-cards > li.article-card {
    min-width: 0;
    width: auto;
    max-width: none;
    margin: 0;
    float: none;
    box-sizing: border-box;
    background: var(--white);
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-lg);
    overflow: hidden;
    transition: var(--transition);
}

ul.article-cards > li.article-card:hover {
    border-color: var(--black);
    box-shadow: 0 8px 24px rgba(0,0,0,0.08);
    transform: translateY(-2px);
}

.article-card .card-thumb {
    width: 100%;
    overflow: hidden;
    aspect-ratio: 16/10;
}

.article-card .card-thumb img {
    display: block;
    width: 100%;
    max-width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.3s ease;
}

.article-card:hover .card-thumb img {
    transform: scale(1.03);
}

.article-card .card-body {
    padding: 20px;
}

.article-card .card-title {
    overflow-wrap: anywhere;
    font-size: 16px;
    font-weight: 600;
    line-height: 1.5;
    margin-bottom: 12px;
    color: var(--black);
}

.article-card .card-title a:hover {
    color: var(--gray-800);
}

.article-card .card-date {
    display: block;
    font-size: 13px;
    color: var(--gray-400);
    margin-bottom: 10px;
}

.article-card .card-summary {
    overflow-wrap: anywhere;
    font-size: 14px;
    color: var(--gray-600);
    line-height: 1.6;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

/* ========================================
   FAQ
======================================== */
.faq-section {
    padding: 100px 0;
}

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

.faq-item {
    border-bottom: 1px solid var(--gray-200);
}

.faq-question {
    width: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 24px 0;
    font-size: 16px;
    font-weight: 500;
    text-align: left;
    color: var(--black);
    transition: var(--transition);
}

.faq-question:hover {
    color: var(--gray-800);
}

.faq-question svg {
    flex-shrink: 0;
    transition: transform 0.2s ease;
    color: var(--gray-400);
}

.faq-item.active .faq-question svg {
    transform: rotate(180deg);
    color: var(--black);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease;
}

.faq-item.active .faq-answer {
    max-height: 500px;
    padding-bottom: 24px;
}

.faq-answer p {
    font-size: 15px;
    color: var(--gray-600);
    line-height: 1.8;
}

/* ========================================
   关于我们
======================================== */
.about-section {
    padding: 100px 0;
    background: var(--gray-50);
}

.about-content {
    max-width: 900px;
}

.about-intro {
    font-size: 17px;
    color: var(--gray-600);
    line-height: 1.8;
    margin-bottom: 40px;
}

.about-services {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 28px;
    margin-bottom: 40px;
}

.about-service h4 {
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 8px;
}

.about-service p {
    font-size: 14px;
    color: var(--gray-600);
    line-height: 1.7;
}

.about-disclaimer {
    padding: 24px;
    background: var(--white);
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-lg);
    font-size: 13px;
    color: var(--gray-600);
    line-height: 1.8;
}

.about-disclaimer strong {
    color: var(--black);
}

/* ========================================
   联系方式
======================================== */
.contact-section {
    padding: 100px 0;
}

.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: start;
}

.contact-info > p {
    font-size: 16px;
    color: var(--gray-600);
    line-height: 1.8;
    margin-bottom: 32px;
}

.contact-methods {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.contact-method {
    display: flex;
    gap: 16px;
}

.contact-icon {
    flex-shrink: 0;
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--gray-100);
    border-radius: var(--radius);
}

.contact-method h4 {
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 4px;
}

.contact-phone {
    font-size: 20px;
    font-weight: 700;
    color: var(--black);
    display: inline-block;
    margin-bottom: 4px;
}

.contact-method p {
    font-size: 13px;
    color: var(--gray-600);
}

.contact-form-card {
    padding: 40px;
    background: var(--white);
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-lg);
}

.contact-form-card h3 {
    font-size: 22px;
    font-weight: 600;
    margin-bottom: 8px;
}

.contact-form-card > p {
    font-size: 14px;
    color: var(--gray-600);
    margin-bottom: 28px;
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    font-size: 14px;
    font-weight: 500;
    margin-bottom: 8px;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 12px 16px;
    border: 1px solid var(--gray-200);
    border-radius: var(--radius);
    font-family: inherit;
    font-size: 14px;
    color: var(--black);
    background: var(--white);
    transition: var(--transition);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--black);
}

.form-group textarea {
    resize: vertical;
    min-height: 100px;
}

.form-notice {
    margin-top: 12px;
    font-size: 12px;
    color: var(--gray-600);
    line-height: 1.6;
    text-align: center;
}

/* ========================================
   页脚
======================================== */
.site-footer {
    background: var(--black);
    color: var(--white);
    padding: 64px 0 32px;
}

.footer-container {
    max-width: var(--container);
    margin: 0 auto;
    padding: 0 24px;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 48px;
    padding-bottom: 48px;
    border-bottom: 1px solid var(--gray-800);
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 20px;
    font-weight: 700;
    margin-bottom: 20px;
}

.footer-desc {
    font-size: 14px;
    color: var(--gray-400);
    line-height: 1.8;
    margin-bottom: 24px;
}

.footer-phone {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    font-size: 18px;
    font-weight: 600;
    color: var(--white);
}

.footer-phone:hover {
    color: var(--gray-200);
}

.footer-col h4 {
    font-size: 14px;
    font-weight: 600;
    margin-bottom: 20px;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.footer-col ul {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.footer-col a {
    font-size: 14px;
    color: var(--gray-400);
}

.footer-col a:hover {
    color: var(--white);
}

.footer-bottom {
    padding-top: 32px;
}

.footer-links {
    display: flex;
    flex-wrap: wrap;
    gap: 16px;
    margin-bottom: 20px;
}

.footer-links a {
    font-size: 13px;
    color: var(--gray-400);
}

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

.footer-copyright p {
    font-size: 12px;
    color: var(--gray-600);
    line-height: 1.8;
}

/* ========================================
   文章详情页
======================================== */
.article-page {
    padding: 60px 0;
}

.article-breadcrumb {
    margin-bottom: 32px;
    font-size: 14px;
    color: var(--gray-600);
}

.article-breadcrumb a {
    color: var(--gray-600);
}

.article-breadcrumb a:hover {
    color: var(--black);
}

.article-content {
    max-width: 800px;
    margin: 0 auto;
}

.article-header {
    margin-bottom: 32px;
}

.article-title {
    font-size: 36px;
    font-weight: 700;
    line-height: 1.3;
    margin-bottom: 20px;
}

.article-meta {
    display: flex;
    align-items: center;
    gap: 20px;
    margin-bottom: 20px;
    color: var(--gray-400);
    font-size: 14px;
}

.article-date {
    display: flex;
    align-items: center;
    gap: 6px;
}

.article-summary {
    padding: 20px 24px;
    background: var(--gray-100);
    border-left: 3px solid var(--black);
    font-size: 16px;
    color: var(--gray-800);
    line-height: 1.8;
    border-radius: var(--radius);
}

.article-cover {
    margin-bottom: 40px;
    border-radius: var(--radius-lg);
    overflow: hidden;
}

.article-cover img {
    width: 100%;
}

.article-body {
    font-size: 16px;
    line-height: 1.9;
    color: var(--dark);
}

.article-body h2,
.article-body h3,
.article-body h4 {
    margin-top: 40px;
    margin-bottom: 16px;
    font-weight: 600;
}

.article-body h2 { font-size: 26px; }
.article-body h3 { font-size: 22px; }
.article-body h4 { font-size: 18px; }

.article-body p {
    margin-bottom: 20px;
}

.article-body ul,
.article-body ol {
    margin-bottom: 20px;
    padding-left: 24px;
}

.article-body li {
    margin-bottom: 8px;
}

.article-body img {
    max-width: 100%;
    border-radius: var(--radius-lg);
    margin: 24px 0;
}

.article-body blockquote {
    padding: 20px 24px;
    background: var(--gray-100);
    border-left: 3px solid var(--black);
    margin: 24px 0;
    border-radius: var(--radius);
}

.article-related {
    max-width: 800px;
    margin: 60px auto 0;
    padding-top: 40px;
    border-top: 1px solid var(--gray-200);
}

.article-related h3 {
    font-size: 22px;
    font-weight: 600;
    margin-bottom: 24px;
}

.related-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
}

.related-card {
    display: flex;
    gap: 16px;
    padding: 20px;
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-lg);
    transition: var(--transition);
}

.related-card:hover {
    border-color: var(--black);
    background: var(--gray-50);
}

.related-icon {
    flex-shrink: 0;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--gray-100);
    border-radius: var(--radius);
}

.related-card h4 {
    font-size: 15px;
    font-weight: 600;
    margin-bottom: 4px;
}

.related-card p {
    font-size: 13px;
    color: var(--gray-600);
    line-height: 1.5;
}

.article-cta {
    max-width: 800px;
    margin: 40px auto 0;
    padding: 32px;
    background: var(--black);
    color: var(--white);
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 24px;
}

.cta-content h3 {
    font-size: 20px;
    font-weight: 600;
    margin-bottom: 8px;
}

.cta-content p {
    font-size: 14px;
    color: var(--gray-400);
}

.cta-actions {
    display: flex;
    gap: 12px;
    flex-shrink: 0;
}

.cta-actions .btn-outline {
    border-color: var(--white);
    color: var(--white);
}

.cta-actions .btn-outline:hover {
    background: var(--white);
    color: var(--black);
}

.cta-actions .btn-primary {
    background: var(--white);
    color: var(--black);
}

.cta-actions .btn-primary:hover {
    background: var(--gray-200);
}

/* ========================================
   渐入动画
======================================== */
.fade-in {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

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

/* ========================================
   响应式
======================================== */
@media (max-width: 1024px) {
    .platforms-grid,
    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .guide-steps {
        grid-template-columns: repeat(2, 1fr);
        gap: 24px;
    }
    
    .footer-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 32px;
    }
    
    .contact-grid {
        grid-template-columns: 1fr;
        gap: 40px;
    }
}

@media (max-width: 768px) {
    .main-nav {
        display: none;
        position: fixed;
        top: 72px;
        left: 0;
        right: 0;
        background: var(--white);
        padding: 20px;
        border-bottom: 1px solid var(--gray-200);
        box-shadow: 0 10px 30px rgba(0,0,0,0.1);
    }
    
    .main-nav.active {
        display: block;
    }
    
    .main-nav ul {
        flex-direction: column;
        gap: 0;
    }
    
    .main-nav li {
        border-bottom: 1px solid var(--gray-100);
    }
    
    .main-nav a {
        display: block;
        padding: 14px 0;
    }
    
    .mobile-toggle {
        display: flex;
    }
    
    .header-phone span:not(svg) {
        display: none;
    }
    
    .header-phone {
        padding: 10px 12px;
    }
    
    .hero {
        padding: 40px 0 60px;
    }
    
    .hero-container {
        grid-template-columns: 1fr;
        gap: 40px;
    }
    
    .hero-title {
        font-size: 32px;
    }
    
    .hero-actions {
        flex-direction: column;
    }
    
    .btn {
        justify-content: center;
    }
    
    .section-header h2 {
        font-size: 28px;
    }
    
    .platforms-section,
    .downloads-section,
    .features-section,
    .guide-section,
    .security-section,
    .news-section,
    .faq-section,
    .about-section,
    .contact-section {
        padding: 60px 0;
    }
    
    .platforms-grid,
    .features-grid,
    .security-grid,
    .about-services,
    .related-grid {
        grid-template-columns: 1fr;
    }
    
    .download-item {
        flex-direction: column;
        align-items: flex-start;
    }
    
    .download-actions {
        width: 100%;
        justify-content: space-between;
    }
    
    .device-tabs {
        gap: 0;
    }
    
    .device-tab {
        padding: 12px 16px;
        font-size: 13px;
    }
    
    .security-card {
        padding: 28px 24px;
    }
    
    .security-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 12px;
    }
    
    .security-header h2 {
        font-size: 22px;
    }
    
    .contact-form-card {
        padding: 24px;
    }
    
    .footer-grid {
        grid-template-columns: 1fr;
        gap: 32px;
    }
    
    .article-title {
        font-size: 26px;
    }
    
    .article-cta {
        flex-direction: column;
        text-align: center;
    }
    
    .cta-actions {
        width: 100%;
        flex-direction: column;
    }
}

@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
    
    html {
        scroll-behavior: auto;
    }
    
    .fade-in {
        opacity: 1;
        transform: none;
    }
}