/* ===== 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, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", 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; }

/* ===== Container ===== */
.container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }

/* ===== Header / Nav ===== */
.site-header {
    position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
    background: rgba(255,255,255,.97); border-bottom: 1px solid #e8ecf1;
    backdrop-filter: blur(8px);
}
.nav-inner {
    max-width: 1200px; margin: 0 auto; padding: 0 20px;
    display: flex; align-items: center; justify-content: space-between; height: 68px;
}
.logo { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 1.4rem; color: #1a56db; }
.logo-icon {
    width: 36px; height: 36px; background: linear-gradient(135deg, #1a56db, #3b82f6);
    border-radius: 10px; display: flex; align-items: center; justify-content: center;
    color: #fff; font-weight: 900; font-size: 1.1rem;
}
.nav-links { display: flex; align-items: center; gap: 32px; }
.nav-links a { font-size: .95rem; color: #4b5563; font-weight: 500; position: relative; padding: 4px 0; }
.nav-links a:hover { color: #1a56db; }
.nav-links a::after {
    content: ''; position: absolute; bottom: -2px; left: 0; width: 0; height: 2px;
    background: #1a56db; transition: width .25s;
}
.nav-links a:hover::after { width: 100%; }
.nav-cta {
    display: inline-block; padding: 10px 24px; background: linear-gradient(135deg, #1a56db, #3b82f6);
    color: #fff !important; border-radius: 8px; font-weight: 600; font-size: .9rem;
    transition: transform .2s, box-shadow .2s;
}
.nav-cta:hover { transform: translateY(-1px); box-shadow: 0 4px 14px rgba(26,86,219,.35); }
.nav-cta::after { display: none !important; }

/* Mobile menu */
.menu-toggle { display: none; background: none; border: none; cursor: pointer; padding: 8px; }
.menu-toggle span { display: block; width: 24px; height: 2px; background: #333; margin: 5px 0; transition: .3s; }

/* ===== Hero ===== */
.hero {
    padding: 160px 0 100px; text-align: center;
    background: linear-gradient(170deg, #eef4ff 0%, #f8faff 40%, #fff 100%);
    position: relative; overflow: hidden;
}
.hero::before {
    content: ''; position: absolute; top: -50%; right: -20%; width: 600px; height: 600px;
    background: radial-gradient(circle, rgba(59,130,246,.08) 0%, transparent 70%);
    border-radius: 50%;
}
.hero::after {
    content: ''; position: absolute; bottom: -30%; left: -10%; width: 500px; height: 500px;
    background: radial-gradient(circle, rgba(26,86,219,.06) 0%, transparent 70%);
    border-radius: 50%;
}
.hero-content { position: relative; z-index: 1; }
.hero h1 { font-size: 3rem; font-weight: 800; color: #111827; margin-bottom: 16px; letter-spacing: -0.02em; }
.hero h1 span { color: #1a56db; }
.hero .subtitle { font-size: 1.25rem; color: #6b7280; margin-bottom: 12px; }
.hero .badges { display: flex; justify-content: center; gap: 24px; margin-bottom: 40px; flex-wrap: wrap; }
.hero .badge {
    display: inline-flex; align-items: center; gap: 6px;
    padding: 6px 16px; background: #fff; border: 1px solid #e5e7eb;
    border-radius: 20px; font-size: .85rem; color: #4b5563;
}
.hero-btns { display: flex; justify-content: center; gap: 16px; flex-wrap: wrap; }
.btn-primary {
    display: inline-block; padding: 14px 36px;
    background: linear-gradient(135deg, #1a56db, #3b82f6);
    color: #fff; border-radius: 10px; font-weight: 700; font-size: 1.05rem;
    transition: transform .2s, box-shadow .2s;
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 6px 20px rgba(26,86,219,.35); }
.btn-secondary {
    display: inline-block; padding: 14px 36px;
    background: #fff; color: #1a56db; border: 2px solid #1a56db;
    border-radius: 10px; font-weight: 700; font-size: 1.05rem;
    transition: background .2s, color .2s;
}
.btn-secondary:hover { background: #1a56db; color: #fff; }

/* ===== Section Common ===== */
.section { padding: 80px 0; }
.section-alt { background: #f8faff; }
.section-title { text-align: center; margin-bottom: 56px; }
.section-title h2 { font-size: 2rem; font-weight: 700; color: #111827; margin-bottom: 12px; }
.section-title p { font-size: 1.05rem; color: #6b7280; max-width: 600px; margin: 0 auto; }

/* ===== Highlights ===== */
.highlights-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.highlight-card {
    background: #fff; border: 1px solid #e5e7eb; border-radius: 16px;
    padding: 36px 28px; text-align: center;
    transition: transform .25s, box-shadow .25s;
}
.highlight-card:hover { transform: translateY(-6px); box-shadow: 0 12px 32px rgba(0,0,0,.08); }
.highlight-icon {
    width: 64px; height: 64px; margin: 0 auto 20px;
    background: linear-gradient(135deg, #eef4ff, #dbeafe);
    border-radius: 16px; display: flex; align-items: center; justify-content: center;
    font-size: 1.8rem;
}
.highlight-card h3 { font-size: 1.15rem; font-weight: 700; color: #111827; margin-bottom: 10px; }
.highlight-card p { font-size: .9rem; color: #6b7280; line-height: 1.6; }

/* ===== Downloads ===== */
.downloads-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.download-card {
    background: #fff; border: 1px solid #e5e7eb; border-radius: 16px;
    padding: 40px 24px; text-align: center;
    transition: transform .25s, box-shadow .25s;
}
.download-card:hover { transform: translateY(-4px); box-shadow: 0 8px 24px rgba(0,0,0,.08); }
.download-card .platform-icon { font-size: 2.8rem; margin-bottom: 16px; }
.download-card h3 { font-size: 1.1rem; font-weight: 700; color: #111827; margin-bottom: 8px; }
.download-card .version { font-size: .8rem; color: #9ca3af; margin-bottom: 20px; }
.download-btn {
    display: inline-block; padding: 12px 28px;
    background: linear-gradient(135deg, #1a56db, #3b82f6);
    color: #fff; border-radius: 8px; font-weight: 600; font-size: .9rem;
    transition: transform .2s, box-shadow .2s;
}
.download-btn:hover { transform: translateY(-1px); box-shadow: 0 4px 14px rgba(26,86,219,.3); }

/* ===== Advantages ===== */
.advantage-row {
    display: flex; align-items: center; gap: 60px; margin-bottom: 60px;
}
.advantage-row:nth-child(even) { flex-direction: row-reverse; }
.advantage-row:last-child { margin-bottom: 0; }
.advantage-text { flex: 1; }
.advantage-text h3 { font-size: 1.5rem; font-weight: 700; color: #111827; margin-bottom: 16px; }
.advantage-text p { font-size: 1rem; color: #6b7280; line-height: 1.8; margin-bottom: 12px; }
.advantage-text ul { padding-left: 0; }
.advantage-text li {
    position: relative; padding-left: 24px; margin-bottom: 8px;
    font-size: .95rem; color: #4b5563;
}
.advantage-text li::before {
    content: ''; position: absolute; left: 0; top: 8px;
    width: 8px; height: 8px; background: #3b82f6; border-radius: 50%;
}
.advantage-visual {
    flex: 1; display: flex; align-items: center; justify-content: center;
}
.advantage-img {
    width: 100%; max-width: 400px; height: 260px;
    background: linear-gradient(135deg, #eef4ff, #dbeafe);
    border-radius: 20px; display: flex; align-items: center; justify-content: center;
    font-size: 4rem;
}

/* ===== Testimonials ===== */
.testimonials-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.testimonial-card {
    background: #fff; border: 1px solid #e5e7eb; border-radius: 16px;
    padding: 32px; transition: box-shadow .25s;
}
.testimonial-card:hover { box-shadow: 0 8px 24px rgba(0,0,0,.06); }
.testimonial-stars { color: #f59e0b; font-size: 1rem; margin-bottom: 16px; letter-spacing: 2px; }
.testimonial-text { font-size: .95rem; color: #4b5563; line-height: 1.7; margin-bottom: 20px; font-style: italic; }
.testimonial-author { display: flex; align-items: center; gap: 12px; }
.testimonial-avatar {
    width: 44px; height: 44px; border-radius: 50%;
    background: linear-gradient(135deg, #1a56db, #3b82f6);
    display: flex; align-items: center; justify-content: center;
    color: #fff; font-weight: 700; font-size: .9rem;
}
.testimonial-name { font-weight: 600; color: #111827; font-size: .9rem; }
.testimonial-role { font-size: .8rem; color: #9ca3af; }
.stats-bar {
    display: flex; justify-content: center; gap: 60px; margin-top: 48px;
    padding-top: 40px; border-top: 1px solid #e5e7eb;
}
.stat-item { text-align: center; }
.stat-number { font-size: 2.2rem; font-weight: 800; color: #1a56db; }
.stat-label { font-size: .85rem; color: #6b7280; margin-top: 4px; }

/* ===== FAQ ===== */
.faq-list { max-width: 800px; margin: 0 auto; }
.faq-item {
    border: 1px solid #e5e7eb; border-radius: 12px;
    margin-bottom: 16px; overflow: hidden; background: #fff;
}
.faq-question {
    padding: 20px 24px; font-weight: 700; font-size: 1.05rem; color: #111827;
    background: #f9fafb; border-bottom: 1px solid #e5e7eb;
    display: flex; align-items: center; gap: 12px;
}
.faq-question .q-icon {
    width: 28px; height: 28px; background: #1a56db; color: #fff;
    border-radius: 6px; display: flex; align-items: center; justify-content: center;
    font-size: .8rem; font-weight: 700; flex-shrink: 0;
}
.faq-answer { padding: 24px; }
.faq-answer p { font-size: .95rem; color: #4b5563; line-height: 1.8; margin-bottom: 12px; }
.faq-steps { padding-left: 0; counter-reset: step; }
.faq-steps li {
    counter-increment: step; position: relative;
    padding: 12px 16px 12px 52px; margin-bottom: 8px;
    background: #f8faff; border-radius: 8px;
    font-size: .9rem; color: #4b5563; line-height: 1.7;
}
.faq-steps li::before {
    content: counter(step);
    position: absolute; left: 16px; top: 12px;
    width: 24px; height: 24px; background: #1a56db; color: #fff;
    border-radius: 50%; display: flex; align-items: center; justify-content: center;
    font-size: .75rem; font-weight: 700;
}

/* ===== Guide Steps ===== */
.guide-steps { max-width: 800px; margin: 0 auto; }
.guide-step {
    display: flex; gap: 24px; margin-bottom: 40px; align-items: flex-start;
}
.guide-step-num {
    width: 48px; height: 48px; flex-shrink: 0;
    background: linear-gradient(135deg, #1a56db, #3b82f6);
    color: #fff; border-radius: 50%;
    display: flex; align-items: center; justify-content: center;
    font-size: 1.2rem; font-weight: 700;
}
.guide-step-content h3 { font-size: 1.15rem; font-weight: 700; color: #111827; margin-bottom: 8px; }
.guide-step-content p { font-size: .95rem; color: #6b7280; line-height: 1.7; }

/* ===== About ===== */
.about-intro { max-width: 800px; margin: 0 auto; text-align: center; margin-bottom: 60px; }
.about-intro p { font-size: 1.05rem; color: #4b5563; line-height: 1.8; margin-bottom: 16px; }
.about-values { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.about-value-card {
    background: #fff; border: 1px solid #e5e7eb; border-radius: 16px;
    padding: 36px 28px; text-align: center;
}
.about-value-card .value-icon { font-size: 2.4rem; margin-bottom: 16px; }
.about-value-card h3 { font-size: 1.1rem; font-weight: 700; color: #111827; margin-bottom: 10px; }
.about-value-card p { font-size: .9rem; color: #6b7280; line-height: 1.7; }

/* ===== Footer ===== */
.site-footer { background: #111827; color: #d1d5db; padding: 60px 0 0; }
.footer-grid {
    display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 40px;
    padding-bottom: 40px; border-bottom: 1px solid #1f2937;
}
.footer-brand .logo { color: #fff; margin-bottom: 16px; }
.footer-brand p { font-size: .9rem; color: #9ca3af; line-height: 1.7; }
.footer-col h4 { font-size: .95rem; font-weight: 700; color: #fff; margin-bottom: 16px; }
.footer-col a { display: block; font-size: .9rem; color: #9ca3af; margin-bottom: 10px; transition: color .2s; }
.footer-col a:hover { color: #3b82f6; }
.footer-bottom {
    padding: 20px 0; text-align: center; font-size: .8rem; color: #6b7280;
}

/* ===== Page Header (for inner pages) ===== */
.page-header {
    padding: 140px 0 60px; text-align: center;
    background: linear-gradient(170deg, #eef4ff 0%, #f8faff 40%, #fff 100%);
}
.page-header h1 { font-size: 2.4rem; font-weight: 800; color: #111827; margin-bottom: 12px; }
.page-header p { font-size: 1.1rem; color: #6b7280; max-width: 600px; margin: 0 auto; }

/* ===== Breadcrumb ===== */
.breadcrumb { padding: 16px 0; font-size: .85rem; color: #9ca3af; }
.breadcrumb a { color: #6b7280; }
.breadcrumb a:hover { color: #1a56db; }
.breadcrumb span { margin: 0 8px; }

/* ===== Legal Pages ===== */
.legal-content { max-width: 800px; margin: 0 auto; }
.legal-content h2 { font-size: 1.3rem; font-weight: 700; color: #111827; margin: 32px 0 12px; }
.legal-content p { font-size: .95rem; color: #4b5563; line-height: 1.8; margin-bottom: 12px; }
.legal-content ul { padding-left: 20px; margin-bottom: 16px; }
.legal-content li { font-size: .95rem; color: #4b5563; line-height: 1.8; margin-bottom: 6px; list-style: disc; }

/* ===== Responsive ===== */
@media (max-width: 1024px) {
    .highlights-grid, .downloads-grid { grid-template-columns: repeat(2, 1fr); }
    .testimonials-grid { grid-template-columns: repeat(2, 1fr); }
    .footer-grid { grid-template-columns: repeat(2, 1fr); }
    .advantage-row { flex-direction: column !important; gap: 30px; }
    .about-values { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 768px) {
    .nav-links { display: none; }
    .menu-toggle { display: block; }
    .nav-links.active {
        display: flex; flex-direction: column; position: absolute;
        top: 68px; left: 0; right: 0; background: #fff;
        padding: 20px; gap: 16px; border-bottom: 1px solid #e5e7eb;
        box-shadow: 0 4px 12px rgba(0,0,0,.08);
    }
    .hero { padding: 120px 0 60px; }
    .hero h1 { font-size: 2rem; }
    .hero .subtitle { font-size: 1rem; }
    .hero .badges { gap: 12px; }
    .hero-btns { flex-direction: column; align-items: center; }
    .highlights-grid, .downloads-grid { grid-template-columns: 1fr; }
    .testimonials-grid { grid-template-columns: 1fr; }
    .stats-bar { flex-direction: column; gap: 24px; }
    .footer-grid { grid-template-columns: 1fr; }
    .section { padding: 50px 0; }
    .section-title h2 { font-size: 1.6rem; }
    .about-values { grid-template-columns: 1fr; }
    .guide-step { flex-direction: column; gap: 12px; }
}