/* ============================================================
   帧速大师 · SEO 文章页共享样式
   风格与原站 index.html 保持一致：深色科技感 + 青紫渐变
   ============================================================ */
:root {
    --primary-cyan: #00f5ff;
    --primary-purple: #b400ff;
    --primary-blue: #0066ff;
    --bg-dark: #0a0a1a;
    --bg-darker: #050510;
    --text-light: #ffffff;
    --text-gray: #b8b8d0;
    --text-body: #cdd2e8;
    --card-bg: rgba(12, 14, 36, 0.72);
    --border-cyan: rgba(0, 245, 255, 0.18);
    --radius: 18px;
    --gradient: linear-gradient(90deg, var(--primary-cyan), var(--primary-purple));
}

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

html { scroll-behavior: smooth; }

body {
    font-family: 'Microsoft YaHei', 'PingFang SC', -apple-system, BlinkMacSystemFont, 'Noto Sans SC', sans-serif;
    background: var(--bg-dark);
    color: var(--text-light);
    overflow-x: hidden;
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
}

/* ============ 背景网格动效 ============ */
.bg-animation {
    position: fixed;
    inset: 0;
    background:
        linear-gradient(135deg, rgba(180, 0, 255, 0.07) 0%, rgba(0, 245, 255, 0.07) 100%),
        var(--bg-dark);
    z-index: -1;
    overflow: hidden;
}
.bg-animation::before {
    content: '';
    position: absolute;
    top: -50%; left: -50%;
    width: 200%; height: 200%;
    background: radial-gradient(circle, rgba(0, 245, 255, 0.09) 1px, transparent 1px);
    background-size: 46px 46px;
    animation: gridMove 22s linear infinite;
}
.bg-animation::after {
    content: '';
    position: absolute;
    inset: 0;
    background: radial-gradient(ellipse 60% 45% at 50% 0%, rgba(180, 0, 255, 0.14), transparent 70%);
}
@keyframes gridMove {
    0% { transform: translate(0, 0); }
    100% { transform: translate(46px, 46px); }
}

/* ============ 顶部导航 ============ */
.navbar {
    position: fixed;
    top: 0; left: 0;
    width: 100%;
    background: rgba(8, 8, 22, 0.92);
    backdrop-filter: blur(18px);
    -webkit-backdrop-filter: blur(18px);
    border-bottom: 1px solid var(--border-cyan);
    z-index: 1000;
    padding: 14px 0;
}
.nav-container {
    max-width: 1320px;
    margin: 0 auto;
    padding: 0 22px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.logo {
    font-size: 26px;
    font-weight: 900;
    letter-spacing: 2px;
    background: var(--gradient);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    text-decoration: none;
    white-space: nowrap;
}
.nav-menu {
    display: flex;
    list-style: none;
    gap: 30px;
    align-items: center;
}
.nav-menu a {
    color: var(--text-gray);
    text-decoration: none;
    font-size: 15px;
    transition: color .3s;
    position: relative;
}
.nav-menu a::after {
    content: '';
    position: absolute;
    bottom: -6px; left: 0;
    width: 0; height: 2px;
    background: var(--primary-cyan);
    transition: width .3s;
}
.nav-menu a:hover { color: var(--primary-cyan); }
.nav-menu a:hover::after { width: 100%; }
.nav-menu a.active { color: var(--primary-cyan); }
.nav-cta {
    padding: 8px 20px !important;
    border: 1px solid var(--primary-cyan);
    border-radius: 40px;
    color: var(--primary-cyan) !important;
}
.nav-cta:hover {
    background: rgba(0, 245, 255, 0.12);
    box-shadow: 0 0 18px rgba(0, 245, 255, 0.35);
}
.mobile-menu-btn {
    display: none;
    background: none;
    border: 1.5px solid var(--primary-cyan);
    color: var(--primary-cyan);
    font-size: 22px;
    padding: 6px 11px;
    cursor: pointer;
    border-radius: 8px;
    line-height: 1;
}

/* ============ 文章页 Hero ============ */
.article-hero {
    padding: 148px 20px 46px;
    text-align: center;
    position: relative;
}
.breadcrumb {
    display: inline-flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 6px;
    align-items: center;
    font-size: 13px;
    color: var(--text-gray);
    background: rgba(10, 10, 26, 0.7);
    border: 1px solid var(--border-cyan);
    padding: 8px 20px;
    border-radius: 40px;
    margin-bottom: 26px;
}
.breadcrumb a {
    color: var(--primary-cyan);
    text-decoration: none;
}
.breadcrumb a:hover { text-decoration: underline; }
.article-hero .hero-badge {
    display: inline-block;
    background: rgba(180, 0, 255, 0.16);
    border: 1px solid rgba(180, 0, 255, 0.55);
    color: #d88bff;
    padding: 7px 22px;
    border-radius: 40px;
    font-size: 14px;
    font-weight: 700;
    letter-spacing: 1px;
    margin-bottom: 22px;
}
.article-hero h1 {
    font-size: 42px;
    font-weight: 900;
    line-height: 1.35;
    max-width: 980px;
    margin: 0 auto 18px;
    background: var(--gradient);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    text-shadow: 0 0 42px rgba(0, 245, 255, 0.25);
}
.hero-sub {
    font-size: 17px;
    color: var(--text-gray);
    max-width: 820px;
    margin: 0 auto 26px;
    line-height: 1.9;
}
.hero-meta {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 10px 14px;
    font-size: 13px;
    color: var(--text-gray);
}
.hero-meta span {
    display: inline-flex;
    align-items: center;
    gap: 5px;
    background: rgba(10, 10, 26, 0.75);
    border: 1px solid rgba(255, 255, 255, 0.1);
    padding: 5px 14px;
    border-radius: 30px;
}
.hero-meta b { color: var(--primary-cyan); font-weight: 600; }

/* ============ 快速要点条 ============ */
.key-strip {
    max-width: 1000px;
    margin: 10px auto 0;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 14px;
    padding: 0 20px;
}
.key-strip .chip {
    background: var(--card-bg);
    border: 1px solid var(--border-cyan);
    border-radius: 14px;
    padding: 14px 18px;
    text-align: center;
    font-size: 14px;
    color: var(--text-gray);
    backdrop-filter: blur(6px);
}
.key-strip .chip b {
    display: block;
    font-size: 22px;
    color: var(--primary-cyan);
    font-weight: 900;
    margin-bottom: 3px;
    letter-spacing: 1px;
}

/* ============ 文章正文 ============ */
.article-wrap {
    max-width: 900px;
    margin: 0 auto;
    padding: 40px 20px 20px;
}
.article-body {
    background: var(--card-bg);
    border: 1px solid var(--border-cyan);
    border-radius: 22px;
    padding: 52px 58px;
    backdrop-filter: blur(8px);
    box-shadow: 0 30px 80px rgba(0, 0, 0, 0.45);
}
.article-body p {
    color: var(--text-body);
    font-size: 16.5px;
    line-height: 2.05;
    margin-bottom: 20px;
    text-align: justify;
}
.article-body p:last-child { margin-bottom: 0; }
.article-body strong {
    color: var(--primary-cyan);
    font-weight: 700;
}
.article-body .hot {
    color: #ff9de2;
}
.article-body h2 {
    font-size: 26px;
    font-weight: 800;
    color: var(--text-light);
    margin: 42px 0 20px;
    padding-left: 16px;
    border-left: 4px solid var(--primary-purple);
    background: linear-gradient(90deg, rgba(180, 0, 255, 0.12), transparent 70%);
    border-radius: 0 10px 10px 0;
    line-height: 1.5;
}
.article-body h3 {
    font-size: 20px;
    font-weight: 700;
    color: var(--primary-cyan);
    margin: 30px 0 14px;
}
.article-body code {
    background: rgba(0, 245, 255, 0.1);
    border: 1px solid rgba(0, 245, 255, 0.25);
    color: #8ff8ff;
    padding: 1px 7px;
    border-radius: 6px;
    font-size: 0.88em;
    font-family: Consolas, 'Courier New', monospace;
    white-space: nowrap;
}
.article-body ul {
    list-style: none;
    margin: 0 0 20px;
}
.article-body ul li {
    position: relative;
    color: var(--text-body);
    font-size: 16px;
    line-height: 1.9;
    padding: 6px 0 6px 28px;
}
.article-body ul li::before {
    content: '✦';
    position: absolute;
    left: 4px;
    top: 8px;
    color: var(--primary-purple);
}
.key-box {
    background: linear-gradient(135deg, rgba(0, 245, 255, 0.1), rgba(180, 0, 255, 0.1));
    border: 1px solid rgba(0, 245, 255, 0.35);
    border-left: 5px solid var(--primary-cyan);
    border-radius: 14px;
    padding: 22px 26px;
    margin: 26px 0;
    color: var(--text-light);
    font-size: 16px;
    line-height: 1.95;
}
.key-box strong { color: var(--primary-cyan); }
.note-box {
    background: rgba(180, 0, 255, 0.08);
    border: 1px solid rgba(180, 0, 255, 0.35);
    border-radius: 14px;
    padding: 18px 24px;
    margin: 24px 0;
    color: var(--text-gray);
    font-size: 14.5px;
    line-height: 1.9;
}
.note-box b { color: #d88bff; }

/* ============ FAQ ============ */
.faq-section {
    max-width: 900px;
    margin: 0 auto;
    padding: 70px 20px 20px;
}
.faq-section .section-title {
    text-align: center;
    font-size: 34px;
    margin-bottom: 12px;
    background: var(--gradient);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}
.faq-section .section-sub {
    text-align: center;
    color: var(--text-gray);
    margin-bottom: 40px;
    font-size: 15px;
}
.faq-item {
    background: var(--card-bg);
    border: 1px solid var(--border-cyan);
    border-radius: 14px;
    margin-bottom: 16px;
    overflow: hidden;
    transition: border-color .3s;
}
.faq-item.active { border-color: var(--primary-cyan); }
.faq-question {
    width: 100%;
    padding: 22px 26px;
    background: transparent;
    border: none;
    color: var(--text-light);
    font-size: 17px;
    font-weight: 700;
    text-align: left;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 16px;
    font-family: inherit;
}
.faq-question:hover { color: var(--primary-cyan); }
.faq-icon {
    flex-shrink: 0;
    display: inline-block;
    width: 28px;
    height: 28px;
    line-height: 24px;
    text-align: center;
    border: 1.5px solid var(--primary-cyan);
    border-radius: 50%;
    color: var(--primary-cyan);
    font-size: 18px;
    transition: transform .35s, background .35s;
}
.faq-item.active .faq-icon {
    transform: rotate(45deg);
    background: var(--primary-cyan);
    color: #06202a;
}
.faq-answer {
    padding: 0 26px 24px;
    color: var(--text-body);
    line-height: 1.95;
    font-size: 15.5px;
    display: none;
}
.faq-item.active .faq-answer { display: block; }

/* ============ CTA 授权咨询 ============ */
.contact-section {
    margin: 70px auto 0;
    max-width: 1200px;
    padding: 70px 20px;
    text-align: center;
    background: linear-gradient(135deg, rgba(0, 245, 255, 0.14), rgba(180, 0, 255, 0.14));
    border-top: 1px solid var(--border-cyan);
    border-bottom: 1px solid var(--border-cyan);
}
.contact-title {
    font-size: 40px;
    margin-bottom: 16px;
    background: var(--gradient);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}
.contact-sub {
    color: var(--text-gray);
    font-size: 17px;
    line-height: 1.9;
    margin-bottom: 36px;
}
.contact-buttons {
    display: flex;
    justify-content: center;
    gap: 20px;
    flex-wrap: wrap;
}
.btn-primary, .btn-secondary {
    display: inline-block;
    padding: 16px 44px;
    font-size: 17px;
    font-weight: 700;
    border-radius: 50px;
    cursor: pointer;
    transition: all .3s;
    text-decoration: none;
    border: none;
    font-family: inherit;
}
.btn-primary {
    background: var(--gradient);
    color: #fff;
    box-shadow: 0 8px 26px rgba(0, 245, 255, 0.28);
}
.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 12px 34px rgba(180, 0, 255, 0.4);
}
.btn-secondary {
    background: transparent;
    color: var(--primary-cyan);
    border: 2px solid var(--primary-cyan);
}
.btn-secondary:hover {
    background: rgba(0, 245, 255, 0.1);
    transform: translateY(-3px);
}
.contact-channels {
    margin-top: 34px;
    display: flex;
    justify-content: center;
    gap: 20px;
    flex-wrap: wrap;
}
.channel-card {
    background: var(--card-bg);
    border: 1px solid var(--border-cyan);
    border-radius: 16px;
    padding: 18px 34px;
    min-width: 220px;
    transition: all .3s;
}
.channel-card:hover {
    border-color: var(--primary-purple);
    box-shadow: 0 10px 26px rgba(180, 0, 255, 0.2);
    transform: translateY(-3px);
}
.channel-card h4 {
    color: var(--primary-cyan);
    font-size: 16px;
    margin-bottom: 8px;
}
.channel-card p {
    color: var(--text-light);
    font-size: 22px;
    font-weight: 800;
    letter-spacing: 1px;
    cursor: pointer;
    user-select: all;
}

/* ============ 相关阅读 ============ */
.related-section {
    max-width: 1200px;
    margin: 0 auto;
    padding: 70px 20px 20px;
}
.related-section .section-title {
    text-align: center;
    font-size: 34px;
    margin-bottom: 12px;
    background: var(--gradient);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}
.related-section .section-sub {
    text-align: center;
    color: var(--text-gray);
    margin-bottom: 40px;
    font-size: 15px;
}
.related-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 18px;
}
.related-card {
    display: block;
    text-decoration: none;
    background: var(--card-bg);
    border: 1px solid var(--border-cyan);
    border-radius: 16px;
    padding: 24px 22px;
    transition: all .3s;
    position: relative;
    overflow: hidden;
}
.related-card::before {
    content: '';
    position: absolute;
    top: 0; left: 0;
    width: 100%; height: 3px;
    background: var(--gradient);
    opacity: 0;
    transition: opacity .3s;
}
.related-card:hover {
    transform: translateY(-6px);
    border-color: var(--primary-cyan);
    box-shadow: 0 16px 34px rgba(0, 245, 255, 0.16);
}
.related-card:hover::before { opacity: 1; }
.related-card .tag {
    font-size: 12px;
    color: var(--primary-purple);
    border: 1px solid rgba(180, 0, 255, 0.5);
    border-radius: 20px;
    padding: 2px 12px;
    display: inline-block;
    margin-bottom: 12px;
}
.related-card h4 {
    color: var(--text-light);
    font-size: 17px;
    line-height: 1.6;
    font-weight: 700;
}
.related-card:hover h4 { color: var(--primary-cyan); }

/* ============ 页脚 ============ */
footer {
    background: var(--bg-darker);
    margin-top: 70px;
    padding: 56px 20px 30px;
    border-top: 1px solid var(--border-cyan);
}
.footer-content {
    max-width: 1200px;
    margin: 0 auto 36px;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
    gap: 36px;
}
.footer-section h3 {
    color: var(--primary-cyan);
    font-size: 18px;
    margin-bottom: 16px;
}
.footer-section p, .footer-section a {
    color: var(--text-gray);
    line-height: 2.1;
    text-decoration: none;
    display: block;
    font-size: 14px;
}
.footer-section a:hover { color: var(--primary-cyan); }
.footer-bottom {
    max-width: 1200px;
    margin: 0 auto;
    text-align: center;
    padding-top: 26px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: var(--text-gray);
    font-size: 13px;
}

/* ============ 返回顶部 ============ */
.back-top {
    position: fixed;
    bottom: 28px; right: 28px;
    width: 46px; height: 46px;
    border-radius: 50%;
    background: rgba(10, 10, 26, 0.92);
    border: 1.5px solid var(--primary-cyan);
    color: var(--primary-cyan);
    font-size: 20px;
    cursor: pointer;
    z-index: 999;
    opacity: 0;
    visibility: hidden;
    transform: translateY(12px);
    transition: all .35s;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 0 18px rgba(0, 245, 255, 0.25);
}
.back-top.show {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}
.back-top:hover { background: rgba(0, 245, 255, 0.14); }

/* ============ 滚动进入动画 ============ */
.fade-in {
    opacity: 0;
    transform: translateY(26px);
    transition: opacity .6s ease-out, transform .6s ease-out;
}
.fade-in.visible { opacity: 1; transform: translateY(0); }

/* ============ 响应式 ============ */
@media (max-width: 1024px) {
    .nav-menu { display: none; }
    .mobile-menu-btn { display: block; }
    .navbar.mobile-open .nav-menu {
        display: flex;
        flex-direction: column;
        position: absolute;
        top: 100%; left: 0;
        width: 100%;
        background: rgba(8, 8, 22, 0.98);
        padding: 22px 26px;
        gap: 18px;
        align-items: flex-start;
        border-bottom: 1px solid var(--border-cyan);
    }
    .article-hero h1 { font-size: 34px; }
}
@media (max-width: 768px) {
    .article-hero { padding: 128px 16px 36px; }
    .article-hero h1 { font-size: 27px; }
    .hero-sub { font-size: 15px; }
    .article-body { padding: 30px 22px; }
    .article-body p { font-size: 15.5px; }
    .article-body h2 { font-size: 22px; }
    .contact-title { font-size: 30px; }
    .btn-primary, .btn-secondary { padding: 14px 32px; font-size: 15.5px; }
    .back-top { bottom: 18px; right: 18px; }
}
@media (max-width: 480px) {
    .article-body { padding: 24px 16px; border-radius: 16px; }
    .breadcrumb { font-size: 12px; padding: 6px 14px; }
    .contact-buttons { flex-direction: column; align-items: center; }
}