/* === Reset & Base === */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
    color: #333; background: #fff; line-height: 1.6; overflow-x: hidden;
}
a { text-decoration: none; color: inherit; transition: color .3s; }
img { max-width: 100%; height: auto; display: block; }
ul { list-style: none; }
.container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }

/* === Header === */
.header {
    position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
    background: rgba(15, 23, 42, 0.95); backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(255,255,255,0.08);
    height: 70px; display: flex; align-items: center;
}
.header .container { display: flex; align-items: center; justify-content: space-between; width: 100%; }
.logo { display: flex; align-items: center; gap: 10px; }
.logo-icon {
    width: 40px; height: 40px; background: linear-gradient(135deg, #3b82f6, #06b6d4);
    border-radius: 10px; display: flex; align-items: center; justify-content: center;
    color: #fff; font-weight: 700; font-size: 18px;
}
.logo-text { color: #fff; font-size: 22px; font-weight: 700; letter-spacing: 1px; }
.nav { display: flex; align-items: center; gap: 32px; }
.nav a { color: rgba(255,255,255,0.75); font-size: 15px; font-weight: 500; transition: color .3s; padding: 6px 0; }
.nav a:hover, .nav a.active { color: #fff; }
.nav a.active { border-bottom: 2px solid #3b82f6; }
.header-cta {
    display: inline-block; padding: 10px 24px; background: linear-gradient(135deg, #3b82f6, #2563eb);
    color: #fff; border-radius: 8px; font-size: 14px; font-weight: 600;
    transition: transform .3s, box-shadow .3s;
}
.header-cta:hover { transform: translateY(-2px); box-shadow: 0 8px 25px rgba(59,130,246,0.4); color: #fff; }
.menu-toggle { display: none; flex-direction: column; gap: 5px; cursor: pointer; padding: 5px; }
.menu-toggle span { width: 24px; height: 2px; background: #fff; border-radius: 2px; transition: .3s; }

/* === Hero === */
.hero {
    padding: 140px 0 100px; background: linear-gradient(135deg, #0f172a 0%, #1e293b 50%, #0f172a 100%);
    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 30% 50%, rgba(59,130,246,0.12) 0%, transparent 50%),
                radial-gradient(circle at 70% 50%, rgba(6,182,212,0.08) 0%, transparent 50%);
}
.hero-content { position: relative; z-index: 1; }
.hero h1 { color: #fff; font-size: 48px; font-weight: 800; margin-bottom: 20px; line-height: 1.2; }
.hero h1 span { background: linear-gradient(135deg, #3b82f6, #06b6d4); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }
.hero-sub { color: rgba(255,255,255,0.7); font-size: 20px; margin-bottom: 16px; }
.hero-tags { display: flex; justify-content: center; gap: 20px; margin-bottom: 40px; flex-wrap: wrap; }
.hero-tags span { color: rgba(255,255,255,0.6); font-size: 15px; display: flex; align-items: center; gap: 6px; }
.hero-tags span::before { content: '✓'; color: #3b82f6; font-weight: 700; }
.hero-cta {
    display: inline-block; padding: 16px 48px; background: linear-gradient(135deg, #3b82f6, #2563eb);
    color: #fff; border-radius: 12px; font-size: 18px; font-weight: 700;
    transition: transform .3s, box-shadow .3s; margin-bottom: 30px;
}
.hero-cta:hover { transform: translateY(-3px); box-shadow: 0 12px 35px rgba(59,130,246,0.5); color: #fff; }
.hero-stats { display: flex; justify-content: center; gap: 50px; margin-top: 20px; flex-wrap: wrap; }
.hero-stat { text-align: center; }
.hero-stat .num { color: #fff; font-size: 36px; font-weight: 800; }
.hero-stat .num span { background: linear-gradient(135deg, #3b82f6, #06b6d4); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }
.hero-stat .label { color: rgba(255,255,255,0.5); font-size: 14px; margin-top: 4px; }

/* === Section Common === */
.section { padding: 80px 0; }
.section-dark { background: #f8fafc; }
.section-title { text-align: center; margin-bottom: 60px; }
.section-title h2 { font-size: 36px; font-weight: 700; color: #0f172a; margin-bottom: 12px; }
.section-title p { font-size: 18px; color: #64748b; max-width: 600px; margin: 0 auto; }

/* === Features Grid === */
.features-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 30px; }
.feature-card {
    background: #fff; border: 1px solid #e2e8f0; border-radius: 16px; padding: 36px 28px;
    transition: transform .3s, box-shadow .3s; text-align: center;
}
.feature-card:hover { transform: translateY(-6px); box-shadow: 0 20px 40px rgba(0,0,0,0.08); }
.feature-icon {
    width: 64px; height: 64px; margin: 0 auto 20px; border-radius: 16px;
    display: flex; align-items: center; justify-content: center; font-size: 28px;
    background: linear-gradient(135deg, rgba(59,130,246,0.1), rgba(6,182,212,0.1));
}
.feature-card h3 { font-size: 20px; font-weight: 600; color: #0f172a; margin-bottom: 10px; }
.feature-card p { font-size: 15px; color: #64748b; line-height: 1.7; }

/* === Scenarios === */
.scenarios-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.scenario-card {
    background: #fff; border: 1px solid #e2e8f0; border-radius: 16px; overflow: hidden;
    transition: transform .3s, box-shadow .3s;
}
.scenario-card:hover { transform: translateY(-6px); box-shadow: 0 20px 40px rgba(0,0,0,0.08); }
.scenario-img {
    height: 180px; display: flex; align-items: center; justify-content: center;
    font-size: 56px; background: linear-gradient(135deg, #1e293b, #334155);
}
.scenario-body { padding: 24px; }
.scenario-body h3 { font-size: 18px; font-weight: 600; color: #0f172a; margin-bottom: 8px; }
.scenario-body p { font-size: 14px; color: #64748b; line-height: 1.6; }

/* === Data/Trust === */
.data-section { background: linear-gradient(135deg, #0f172a, #1e293b); padding: 80px 0; }
.data-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 30px; }
.data-card { text-align: center; padding: 30px 20px; }
.data-card .num { font-size: 48px; font-weight: 800; background: linear-gradient(135deg, #3b82f6, #06b6d4); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }
.data-card .unit { font-size: 18px; color: rgba(255,255,255,0.6); margin-top: 4px; }
.data-card .desc { color: rgba(255,255,255,0.5); font-size: 14px; margin-top: 8px; }

/* === Reviews === */
.reviews-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 30px; }
.review-card {
    background: #fff; border: 1px solid #e2e8f0; border-radius: 16px; padding: 32px;
    transition: transform .3s, box-shadow .3s;
}
.review-card:hover { transform: translateY(-4px); box-shadow: 0 15px 35px rgba(0,0,0,0.06); }
.review-stars { color: #f59e0b; font-size: 18px; margin-bottom: 16px; letter-spacing: 2px; }
.review-text { font-size: 15px; color: #475569; line-height: 1.7; margin-bottom: 20px; font-style: italic; }
.review-user { display: flex; align-items: center; gap: 12px; }
.review-avatar {
    width: 44px; height: 44px; border-radius: 50%;
    background: linear-gradient(135deg, #3b82f6, #06b6d4);
    display: flex; align-items: center; justify-content: center;
    color: #fff; font-weight: 700; font-size: 16px;
}
.review-name { font-size: 15px; font-weight: 600; color: #0f172a; }
.review-source { font-size: 13px; color: #94a3b8; }

/* === Download CTA === */
.download-section {
    background: linear-gradient(135deg, #1e40af, #3b82f6);
    padding: 80px 0; text-align: center;
}
.download-section h2 { color: #fff; font-size: 36px; font-weight: 700; margin-bottom: 12px; }
.download-section p { color: rgba(255,255,255,0.8); font-size: 18px; margin-bottom: 40px; }
.download-buttons { display: flex; justify-content: center; gap: 20px; flex-wrap: wrap; margin-bottom: 30px; }
.dl-btn {
    display: inline-flex; align-items: center; gap: 12px;
    padding: 16px 32px; background: rgba(255,255,255,0.15); border: 1px solid rgba(255,255,255,0.3);
    border-radius: 12px; color: #fff; font-size: 16px; font-weight: 600;
    transition: background .3s, transform .3s;
}
.dl-btn:hover { background: rgba(255,255,255,0.25); transform: translateY(-3px); color: #fff; }
.dl-btn .dl-icon { font-size: 28px; }
.dl-btn .dl-label { text-align: left; }
.dl-btn .dl-label small { display: block; font-size: 12px; font-weight: 400; opacity: 0.8; }
.dl-qr { color: rgba(255,255,255,0.7); font-size: 14px; margin-top: 10px; }

/* === FAQ === */
.faq-list { max-width: 800px; margin: 0 auto; }
.faq-item { border: 1px solid #e2e8f0; border-radius: 12px; margin-bottom: 16px; overflow: hidden; }
.faq-question {
    display: block; padding: 20px 24px; background: #f8fafc;
    font-size: 16px; font-weight: 600; color: #0f172a;
    border-bottom: 1px solid #e2e8f0; transition: background .3s;
}
.faq-question:hover { background: #f1f5f9; }
.faq-answer { padding: 24px; }
.faq-answer ol { padding-left: 20px; }
.faq-answer ol li { font-size: 15px; color: #475569; line-height: 1.8; margin-bottom: 8px; list-style: decimal; }
.faq-answer ol li::marker { color: #3b82f6; font-weight: 600; }

/* === Features Page === */
.feature-detail { display: grid; grid-template-columns: 1fr 1fr; gap: 60px; align-items: center; margin-bottom: 80px; }
.feature-detail:nth-child(even) { direction: rtl; }
.feature-detail:nth-child(even) > * { direction: ltr; }
.feature-detail-img {
    height: 320px; border-radius: 20px;
    background: linear-gradient(135deg, #1e293b, #334155);
    display: flex; align-items: center; justify-content: center; font-size: 80px;
}
.feature-detail-text h3 { font-size: 28px; font-weight: 700; color: #0f172a; margin-bottom: 16px; }
.feature-detail-text p { font-size: 16px; color: #64748b; line-height: 1.8; margin-bottom: 16px; }
.feature-detail-text ul li { font-size: 15px; color: #475569; padding: 6px 0; display: flex; align-items: center; gap: 8px; }
.feature-detail-text ul li::before { content: '✓'; color: #3b82f6; font-weight: 700; }

/* === Guide Page === */
.guide-steps { max-width: 800px; margin: 0 auto; }
.guide-step {
    display: flex; gap: 24px; margin-bottom: 40px; padding: 30px;
    background: #fff; border: 1px solid #e2e8f0; border-radius: 16px;
    transition: transform .3s, box-shadow .3s;
}
.guide-step:hover { transform: translateY(-4px); box-shadow: 0 15px 35px rgba(0,0,0,0.06); }
.guide-num {
    flex-shrink: 0; width: 56px; height: 56px; border-radius: 50%;
    background: linear-gradient(135deg, #3b82f6, #2563eb);
    display: flex; align-items: center; justify-content: center;
    color: #fff; font-size: 24px; font-weight: 800;
}
.guide-step-text h3 { font-size: 20px; font-weight: 600; color: #0f172a; margin-bottom: 8px; }
.guide-step-text p { font-size: 15px; color: #64748b; line-height: 1.7; }

/* === Download Page === */
.dl-platforms { display: grid; grid-template-columns: repeat(3, 1fr); gap: 30px; max-width: 900px; margin: 0 auto; }
.dl-platform-card {
    background: #fff; border: 1px solid #e2e8f0; border-radius: 16px; padding: 40px 28px;
    text-align: center; transition: transform .3s, box-shadow .3s;
}
.dl-platform-card:hover { transform: translateY(-6px); box-shadow: 0 20px 40px rgba(0,0,0,0.08); }
.dl-platform-icon { font-size: 56px; margin-bottom: 20px; }
.dl-platform-card h3 { font-size: 22px; font-weight: 600; color: #0f172a; margin-bottom: 8px; }
.dl-platform-card p { font-size: 14px; color: #64748b; margin-bottom: 20px; }
.dl-platform-btn {
    display: inline-block; padding: 12px 36px; background: linear-gradient(135deg, #3b82f6, #2563eb);
    color: #fff; border-radius: 10px; font-size: 15px; font-weight: 600;
    transition: transform .3s, box-shadow .3s;
}
.dl-platform-btn:hover { transform: translateY(-2px); box-shadow: 0 8px 25px rgba(59,130,246,0.4); color: #fff; }

/* === Help Page === */
.help-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 30px; max-width: 900px; margin: 0 auto; }
.help-card {
    background: #fff; border: 1px solid #e2e8f0; border-radius: 16px; padding: 32px;
    transition: transform .3s, box-shadow .3s;
}
.help-card:hover { transform: translateY(-4px); box-shadow: 0 15px 35px rgba(0,0,0,0.06); }
.help-card-icon { font-size: 40px; margin-bottom: 16px; }
.help-card h3 { font-size: 20px; font-weight: 600; color: #0f172a; margin-bottom: 10px; }
.help-card p { font-size: 15px; color: #64748b; line-height: 1.7; margin-bottom: 16px; }
.help-card a.help-link { color: #3b82f6; font-weight: 600; font-size: 14px; }
.help-card a.help-link:hover { color: #2563eb; }

/* === About Page === */
.about-content { max-width: 800px; margin: 0 auto; }
.about-content p { font-size: 16px; color: #475569; line-height: 1.9; margin-bottom: 20px; }
.about-values { display: grid; grid-template-columns: repeat(3, 1fr); gap: 30px; margin-top: 40px; }
.about-value { text-align: center; padding: 30px 20px; background: #f8fafc; border-radius: 16px; }
.about-value-icon { font-size: 40px; margin-bottom: 16px; }
.about-value h3 { font-size: 18px; font-weight: 600; color: #0f172a; margin-bottom: 8px; }
.about-value p { font-size: 14px; color: #64748b; }

/* === Privacy Page === */
.privacy-content { max-width: 800px; margin: 0 auto; }
.privacy-content h2 { font-size: 24px; font-weight: 600; color: #0f172a; margin: 30px 0 12px; }
.privacy-content p { font-size: 15px; color: #475569; line-height: 1.8; margin-bottom: 16px; }
.privacy-content ul { padding-left: 20px; margin-bottom: 16px; }
.privacy-content ul li { font-size: 15px; color: #475569; line-height: 1.8; list-style: disc; margin-bottom: 6px; }

/* === Footer === */
.footer {
    background: #0f172a; padding: 60px 0 30px; border-top: 1px solid rgba(255,255,255,0.08);
}
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 40px; margin-bottom: 40px; }
.footer-brand .logo { margin-bottom: 16px; }
.footer-brand p { color: rgba(255,255,255,0.5); font-size: 14px; line-height: 1.7; }
.footer-col h4 { color: #fff; font-size: 16px; font-weight: 600; margin-bottom: 16px; }
.footer-col a { display: block; color: rgba(255,255,255,0.5); font-size: 14px; padding: 4px 0; transition: color .3s; }
.footer-col a:hover { color: #3b82f6; }
.footer-bottom {
    border-top: 1px solid rgba(255,255,255,0.08); padding-top: 24px;
    display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 12px;
}
.footer-bottom p { color: rgba(255,255,255,0.4); font-size: 13px; }
.footer-bottom a { color: rgba(255,255,255,0.4); font-size: 13px; }
.footer-bottom a:hover { color: #3b82f6; }

/* === Responsive === */
@media (max-width: 1024px) {
    .features-grid { grid-template-columns: repeat(2, 1fr); }
    .scenarios-grid { grid-template-columns: repeat(2, 1fr); }
    .data-grid { grid-template-columns: repeat(2, 1fr); }
    .reviews-grid { grid-template-columns: repeat(2, 1fr); }
    .footer-grid { grid-template-columns: repeat(2, 1fr); }
    .feature-detail { grid-template-columns: 1fr; gap: 30px; }
    .feature-detail:nth-child(even) { direction: ltr; }
    .dl-platforms { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 768px) {
    .nav { display: none; }
    .menu-toggle { display: flex; }
    .header-cta { display: none; }
    .hero h1 { font-size: 32px; }
    .hero-sub { font-size: 16px; }
    .hero-stats { gap: 30px; }
    .hero-stat .num { font-size: 28px; }
    .features-grid { grid-template-columns: 1fr; }
    .scenarios-grid { grid-template-columns: 1fr; }
    .data-grid { grid-template-columns: repeat(2, 1fr); }
    .reviews-grid { grid-template-columns: 1fr; }
    .section-title h2 { font-size: 28px; }
    .footer-grid { grid-template-columns: 1fr; }
    .dl-platforms { grid-template-columns: 1fr; }
    .download-buttons { flex-direction: column; align-items: center; }
    .help-grid { grid-template-columns: 1fr; }
    .about-values { grid-template-columns: 1fr; }
    .guide-step { flex-direction: column; align-items: center; text-align: center; }
}