/* ===== Reset & Base ===== */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
    font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "SF Pro", Arial, sans-serif;
    color: #333; background: #fff; line-height: 1.6;
}
a { text-decoration: none; color: inherit; transition: color .2s; }
ul { list-style: none; }
img { max-width: 100%; display: block; }

/* ===== Utility ===== */
.container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }
.section { padding: 80px 0; }
.section-title { text-align: center; font-size: 36px; font-weight: 700; margin-bottom: 16px; color: #1a1a2e; }
.section-subtitle { text-align: center; font-size: 18px; color: #666; margin-bottom: 50px; max-width: 700px; margin-left: auto; margin-right: auto; }
.btn {
    display: inline-block; padding: 14px 36px; border-radius: 8px; font-size: 16px; font-weight: 600;
    transition: all .3s; cursor: pointer; text-align: center;
}
.btn-primary { background: #2563eb; color: #fff; }
.btn-primary:hover { background: #1d4ed8; transform: translateY(-2px); box-shadow: 0 8px 25px rgba(37,99,235,.3); }
.btn-secondary { background: #fff; color: #2563eb; border: 2px solid #2563eb; }
.btn-secondary:hover { background: #eff6ff; transform: translateY(-2px); }
.btn-white { background: #fff; color: #2563eb; }
.btn-white:hover { background: #f0f4ff; transform: translateY(-2px); box-shadow: 0 8px 25px rgba(0,0,0,.15); }

/* ===== Header ===== */
.header {
    position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
    background: rgba(255,255,255,.95); backdrop-filter: blur(10px);
    border-bottom: 1px solid #e5e7eb; height: 70px;
}
.header .container { display: flex; align-items: center; justify-content: space-between; height: 100%; }
.logo { display: flex; align-items: center; gap: 10px; font-size: 24px; font-weight: 700; color: #2563eb; }
.logo-icon { width: 36px; height: 36px; background: #2563eb; border-radius: 8px; display: flex; align-items: center; justify-content: center; color: #fff; font-weight: 700; font-size: 18px; }
.nav { display: flex; align-items: center; gap: 32px; }
.nav a { font-size: 15px; color: #555; font-weight: 500; transition: color .2s; }
.nav a:hover { color: #2563eb; }
.header-actions { display: flex; align-items: center; gap: 12px; }
.header-actions .btn { padding: 8px 20px; font-size: 14px; }
.mobile-toggle { display: none; flex-direction: column; gap: 5px; cursor: pointer; padding: 5px; }
.mobile-toggle span { width: 24px; height: 2px; background: #333; border-radius: 2px; }

/* ===== Hero ===== */
.hero {
    padding: 160px 0 100px; background: linear-gradient(135deg, #0f172a 0%, #1e3a5f 50%, #1a365d 100%);
    color: #fff; 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(37,99,235,.15) 0%, transparent 50%),
                radial-gradient(circle at 70% 50%, rgba(59,130,246,.1) 0%, transparent 50%);
}
.hero .container { position: relative; z-index: 1; }
.hero h1 { font-size: 48px; font-weight: 800; margin-bottom: 20px; line-height: 1.2; }
.hero h1 span { color: #60a5fa; }
.hero .subtitle { font-size: 20px; color: #94a3b8; margin-bottom: 30px; max-width: 600px; margin-left: auto; margin-right: auto; }
.hero-tags { display: flex; justify-content: center; gap: 16px; margin-bottom: 40px; flex-wrap: wrap; }
.hero-tags .tag {
    background: rgba(255,255,255,.1); border: 1px solid rgba(255,255,255,.2);
    padding: 8px 20px; border-radius: 50px; font-size: 14px; color: #cbd5e1;
}
.hero-buttons { display: flex; justify-content: center; gap: 16px; flex-wrap: wrap; }

/* ===== Features ===== */
.features-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.feature-card {
    background: #fff; border: 1px solid #e5e7eb; border-radius: 16px; padding: 36px 24px;
    text-align: center; transition: all .3s;
}
.feature-card:hover { transform: translateY(-8px); box-shadow: 0 20px 40px rgba(0,0,0,.08); border-color: #2563eb; }
.feature-icon {
    width: 64px; height: 64px; border-radius: 16px; margin: 0 auto 20px;
    display: flex; align-items: center; justify-content: center; font-size: 28px;
    background: #eff6ff; color: #2563eb;
}
.feature-card h3 { font-size: 20px; margin-bottom: 12px; color: #1a1a2e; }
.feature-card p { font-size: 15px; color: #666; line-height: 1.7; }

/* ===== Stats ===== */
.stats { background: linear-gradient(135deg, #1e3a5f, #0f172a); color: #fff; }
.stats-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; text-align: center; }
.stat-item h3 { font-size: 48px; font-weight: 800; color: #60a5fa; margin-bottom: 8px; }
.stat-item p { font-size: 16px; color: #94a3b8; }
.trust-badges { display: flex; justify-content: center; gap: 40px; margin-top: 50px; flex-wrap: wrap; }
.trust-badge {
    display: flex; align-items: center; gap: 10px; background: rgba(255,255,255,.08);
    padding: 12px 24px; border-radius: 10px; border: 1px solid rgba(255,255,255,.1);
}
.trust-badge .badge-icon { font-size: 24px; }
.trust-badge span { font-size: 14px; color: #cbd5e1; }

/* ===== Pricing ===== */
.pricing-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.pricing-card {
    background: #fff; border: 2px solid #e5e7eb; border-radius: 16px; padding: 36px;
    text-align: center; transition: all .3s; position: relative;
}
.pricing-card:hover { transform: translateY(-5px); box-shadow: 0 20px 40px rgba(0,0,0,.08); }
.pricing-card.popular { border-color: #2563eb; transform: scale(1.05); }
.pricing-card.popular:hover { transform: scale(1.05) translateY(-5px); }
.popular-badge {
    position: absolute; top: -14px; left: 50%; transform: translateX(-50%);
    background: #2563eb; color: #fff; padding: 4px 20px; border-radius: 50px; font-size: 13px; font-weight: 600;
}
.pricing-card h3 { font-size: 22px; margin-bottom: 8px; color: #1a1a2e; }
.pricing-card .price { font-size: 42px; font-weight: 800; color: #2563eb; margin: 16px 0; }
.pricing-card .price small { font-size: 16px; color: #999; font-weight: 400; }
.pricing-card .period { font-size: 14px; color: #999; margin-bottom: 20px; }
.pricing-features { text-align: left; margin-bottom: 28px; }
.pricing-features li { padding: 8px 0; font-size: 14px; color: #555; display: flex; align-items: center; gap: 8px; }
.pricing-features li::before { content: '\2713'; color: #2563eb; font-weight: 700; }

/* ===== Reviews ===== */
.reviews { background: #f8fafc; }
.reviews-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.review-card {
    background: #fff; border-radius: 16px; padding: 32px; border: 1px solid #e5e7eb;
    transition: all .3s;
}
.review-card:hover { box-shadow: 0 10px 30px rgba(0,0,0,.06); }
.review-stars { color: #f59e0b; font-size: 18px; margin-bottom: 16px; }
.review-text { font-size: 15px; color: #555; line-height: 1.7; margin-bottom: 20px; }
.review-author { display: flex; align-items: center; gap: 12px; }
.review-avatar {
    width: 44px; height: 44px; border-radius: 50%; background: #eff6ff;
    display: flex; align-items: center; justify-content: center; color: #2563eb; font-weight: 700; font-size: 18px;
}
.review-name { font-weight: 600; font-size: 15px; }
.review-source { font-size: 13px; color: #999; }

/* ===== FAQ ===== */
.faq-list { max-width: 800px; margin: 0 auto; }
.faq-item { border: 1px solid #e5e7eb; border-radius: 12px; margin-bottom: 12px; overflow: hidden; }
.faq-question {
    display: block; padding: 20px 24px; font-size: 16px; font-weight: 600;
    color: #1a1a2e; background: #fff; transition: background .2s;
    cursor: pointer; position: relative;
}
.faq-question:hover { background: #f8fafc; }
.faq-question::after { content: '+'; position: absolute; right: 24px; top: 50%; transform: translateY(-50%); font-size: 22px; color: #2563eb; font-weight: 300; }
.faq-answer { padding: 0 24px 20px; font-size: 15px; color: #555; line-height: 1.8; background: #fff; }
.faq-answer ol { padding-left: 20px; list-style: decimal; }
.faq-answer ol li { padding: 4px 0; }
.faq-item details summary { list-style: none; }
.faq-item details summary::-webkit-details-marker { display: none; }
.faq-item details[open] .faq-question::after { content: '\2212'; }

/* ===== Footer ===== */
.footer { background: #0f172a; color: #94a3b8; padding: 60px 0 30px; }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 40px; margin-bottom: 40px; }
.footer-brand .logo { color: #fff; margin-bottom: 16px; }
.footer-brand p { font-size: 14px; line-height: 1.7; color: #64748b; }
.footer-col h4 { color: #fff; font-size: 16px; margin-bottom: 16px; }
.footer-col a { display: block; font-size: 14px; color: #64748b; padding: 4px 0; transition: color .2s; }
.footer-col a:hover { color: #60a5fa; }
.footer-bottom { border-top: 1px solid #1e293b; padding-top: 24px; text-align: center; font-size: 13px; color: #475569; }

/* ===== Floating ===== */
.floating-btns { position: fixed; right: 20px; bottom: 20px; z-index: 999; display: flex; flex-direction: column; gap: 10px; }
.floating-btn {
    width: 48px; height: 48px; border-radius: 50%; background: #2563eb; color: #fff;
    display: flex; align-items: center; justify-content: center; font-size: 20px;
    box-shadow: 0 4px 15px rgba(37,99,235,.3); transition: all .3s;
}
.floating-btn:hover { transform: translateY(-3px); box-shadow: 0 8px 25px rgba(37,99,235,.4); }

/* ===== Sub Pages ===== */
.page-hero {
    padding: 140px 0 60px; background: linear-gradient(135deg, #0f172a, #1e3a5f);
    color: #fff; text-align: center;
}
.page-hero h1 { font-size: 40px; font-weight: 800; margin-bottom: 12px; }
.page-hero p { font-size: 18px; color: #94a3b8; }

/* Download Page */
.download-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.download-card {
    background: #fff; border: 1px solid #e5e7eb; border-radius: 16px; padding: 40px 24px;
    text-align: center; transition: all .3s;
}
.download-card:hover { transform: translateY(-5px); box-shadow: 0 15px 35px rgba(0,0,0,.08); border-color: #2563eb; }
.download-icon { font-size: 48px; margin-bottom: 16px; }
.download-card h3 { font-size: 20px; margin-bottom: 8px; }
.download-card p { font-size: 14px; color: #666; margin-bottom: 20px; }

/* About Page */
.about-content { max-width: 800px; margin: 0 auto; }
.about-content p { font-size: 16px; color: #555; line-height: 1.8; margin-bottom: 20px; }
.timeline { max-width: 700px; margin: 40px auto 0; }
.timeline-item { display: flex; gap: 24px; margin-bottom: 32px; }
.timeline-dot { width: 16px; height: 16px; border-radius: 50%; background: #2563eb; margin-top: 4px; flex-shrink: 0; }
.timeline-content h4 { font-size: 18px; color: #1a1a2e; margin-bottom: 4px; }
.timeline-content p { font-size: 14px; color: #666; }

/* Help Page */
.help-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 24px; max-width: 900px; margin: 0 auto; }
.help-card {
    background: #fff; border: 1px solid #e5e7eb; border-radius: 12px; padding: 28px;
    transition: all .3s;
}
.help-card:hover { box-shadow: 0 10px 25px rgba(0,0,0,.06); border-color: #2563eb; }
.help-card h3 { font-size: 18px; margin-bottom: 12px; color: #1a1a2e; }
.help-card p { font-size: 14px; color: #666; line-height: 1.7; }
.help-card ol { padding-left: 20px; margin-top: 10px; }
.help-card ol li { font-size: 14px; color: #555; padding: 3px 0; }

/* Privacy / Terms */
.legal-content { max-width: 800px; margin: 0 auto; }
.legal-content h2 { font-size: 24px; color: #1a1a2e; margin: 32px 0 12px; }
.legal-content p { font-size: 15px; color: #555; line-height: 1.8; margin-bottom: 16px; }
.legal-content ul { padding-left: 20px; margin-bottom: 16px; }
.legal-content ul li { font-size: 15px; color: #555; padding: 4px 0; list-style: disc; }

/* ===== Responsive ===== */
@media (max-width: 1024px) {
    .features-grid { grid-template-columns: repeat(2, 1fr); }
    .stats-grid { grid-template-columns: repeat(2, 1fr); gap: 32px; }
    .pricing-grid { grid-template-columns: 1fr; max-width: 420px; margin-left: auto; margin-right: auto; }
    .pricing-card.popular { transform: none; }
    .pricing-card.popular:hover { transform: translateY(-5px); }
    .reviews-grid { grid-template-columns: 1fr; max-width: 500px; margin-left: auto; margin-right: auto; }
    .footer-grid { grid-template-columns: repeat(2, 1fr); }
    .download-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 768px) {
    .nav { display: none; }
    .mobile-toggle { display: flex; }
    .header-actions .btn-secondary { display: none; }
    .hero h1 { font-size: 32px; }
    .hero .subtitle { font-size: 16px; }
    .section-title { font-size: 28px; }
    .features-grid { grid-template-columns: 1fr; }
    .stats-grid { grid-template-columns: repeat(2, 1fr); }
    .stat-item h3 { font-size: 36px; }
    .footer-grid { grid-template-columns: 1fr; }
    .download-grid { grid-template-columns: 1fr; }
    .help-grid { grid-template-columns: 1fr; }
    .hero-buttons { flex-direction: column; align-items: center; }
    .hero-tags { gap: 8px; }
    .hero-tags .tag { font-size: 12px; padding: 6px 14px; }
    .page-hero h1 { font-size: 28px; }
}