/* ===== Reset & Base ===== */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
    font-family: "Source Han Sans SC", "PingFang SC", "Inter", "SF Pro", -apple-system, BlinkMacSystemFont, sans-serif;
    color: #1a1a2e; background: #fff; line-height: 1.6; overflow-x: hidden;
}
a { text-decoration: none; color: inherit; transition: color .3s; }
ul { list-style: none; }
img { max-width: 100%; display: block; }

/* ===== Utility ===== */
.container { max-width: 1200px; margin: 0 auto; padding: 0 24px; }
.section-title { text-align: center; font-size: 2rem; font-weight: 700; margin-bottom: 12px; color: #0f172a; }
.section-subtitle { text-align: center; font-size: 1.05rem; color: #64748b; margin-bottom: 48px; max-width: 640px; margin-left: auto; margin-right: auto; }
.btn-primary {
    display: inline-block; padding: 14px 36px; background: linear-gradient(135deg, #2563eb, #0ea5e9);
    color: #fff; border-radius: 10px; font-size: 1.05rem; font-weight: 600;
    transition: transform .25s, box-shadow .25s; box-shadow: 0 4px 14px rgba(37,99,235,.35);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 6px 20px rgba(37,99,235,.45); color: #fff; }
.btn-outline {
    display: inline-block; padding: 12px 28px; border: 2px solid #2563eb; color: #2563eb;
    border-radius: 10px; font-size: 1rem; font-weight: 600; transition: all .25s;
}
.btn-outline:hover { background: #2563eb; color: #fff; }

/* ===== Header / Nav ===== */
.site-header {
    position: fixed; top: 0; left: 0; width: 100%; z-index: 1000;
    background: rgba(255,255,255,.92); backdrop-filter: blur(12px);
    border-bottom: 1px solid rgba(0,0,0,.06); transition: background .3s;
}
.nav-inner { display: flex; align-items: center; justify-content: space-between; height: 68px; }
.nav-logo { display: flex; align-items: center; gap: 10px; font-size: 1.35rem; font-weight: 700; color: #0f172a; }
.nav-logo img { width: 36px; height: 36px; }
.nav-links { display: flex; align-items: center; gap: 32px; }
.nav-links a { font-size: .95rem; font-weight: 500; color: #475569; transition: color .25s; }
.nav-links a:hover, .nav-links a.active { color: #2563eb; }
.nav-cta { margin-left: 8px; }
.nav-cta .btn-primary { padding: 10px 24px; font-size: .9rem; }
.hamburger { display: none; flex-direction: column; gap: 5px; cursor: pointer; padding: 8px; }
.hamburger span { display: block; width: 24px; height: 2px; background: #0f172a; border-radius: 2px; transition: .3s; }

/* ===== Hero ===== */
.hero {
    position: relative; min-height: 100vh; display: flex; align-items: center; justify-content: center;
    text-align: center; padding: 120px 24px 80px;
    background: linear-gradient(160deg, #0f172a 0%, #1e3a5f 40%, #0c4a6e 70%, #0f172a 100%);
    overflow: hidden;
}
.hero::before {
    content: ""; position: absolute; inset: 0;
    background:
        radial-gradient(circle at 20% 50%, rgba(37,99,235,.15) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(14,165,233,.12) 0%, transparent 50%),
        radial-gradient(circle at 60% 80%, rgba(99,102,241,.1) 0%, transparent 50%);
}
.hero-content { position: relative; z-index: 2; max-width: 800px; }
.hero h1 { font-size: 3.2rem; font-weight: 800; color: #fff; line-height: 1.2; margin-bottom: 20px; }
.hero h1 span { background: linear-gradient(90deg, #38bdf8, #818cf8); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }
.hero p { font-size: 1.2rem; color: rgba(255,255,255,.75); margin-bottom: 36px; max-width: 600px; margin-left: auto; margin-right: auto; }
.hero-badges { display: flex; justify-content: center; gap: 24px; margin-top: 32px; flex-wrap: wrap; }
.hero-badge { display: flex; align-items: center; gap: 8px; color: rgba(255,255,255,.7); font-size: .9rem; }
.hero-badge svg { width: 18px; height: 18px; fill: #38bdf8; }
.hero-cta-group { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }
.hero-cta-group .btn-primary { padding: 16px 44px; font-size: 1.15rem; }
.hero-cta-group .btn-outline { border-color: rgba(255,255,255,.4); color: #fff; }
.hero-cta-group .btn-outline:hover { background: rgba(255,255,255,.1); border-color: #fff; }

/* ===== Highlights ===== */
.highlights { padding: 100px 0; background: #f8fafc; }
.highlights-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 28px; }
.highlight-card {
    background: #fff; border-radius: 16px; padding: 36px 28px; text-align: center;
    box-shadow: 0 1px 3px rgba(0,0,0,.06); transition: transform .3s, box-shadow .3s;
    border: 1px solid #e2e8f0;
}
.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; border-radius: 16px;
    display: flex; align-items: center; justify-content: center;
    background: linear-gradient(135deg, #eff6ff, #e0f2fe);
}
.highlight-icon svg { width: 32px; height: 32px; fill: #2563eb; }
.highlight-card h3 { font-size: 1.15rem; font-weight: 700; margin-bottom: 8px; color: #0f172a; }
.highlight-card p { font-size: .92rem; color: #64748b; line-height: 1.5; }

/* ===== Scenarios ===== */
.scenarios { padding: 100px 0; }
.scenarios-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.scenario-card {
    border-radius: 16px; overflow: hidden; background: #fff;
    box-shadow: 0 2px 8px rgba(0,0,0,.06); transition: transform .3s, box-shadow .3s;
    border: 1px solid #e2e8f0;
}
.scenario-card:hover { transform: translateY(-4px); box-shadow: 0 8px 24px rgba(0,0,0,.1); }
.scenario-img {
    height: 180px; display: flex; align-items: center; justify-content: center;
    font-size: 3.5rem;
}
.scenario-img.office { background: linear-gradient(135deg, #dbeafe, #bfdbfe); }
.scenario-img.study { background: linear-gradient(135deg, #d1fae5, #a7f3d0); }
.scenario-img.game { background: linear-gradient(135deg, #fce7f3, #fbcfe8); }
.scenario-img.mobile { background: linear-gradient(135deg, #fef3c7, #fde68a); }
.scenario-body { padding: 24px; }
.scenario-body h3 { font-size: 1.1rem; font-weight: 700; margin-bottom: 8px; color: #0f172a; }
.scenario-body p { font-size: .9rem; color: #64748b; line-height: 1.5; }

/* ===== Guide ===== */
.guide { padding: 100px 0; background: #f8fafc; }
.guide-steps { display: flex; justify-content: center; gap: 48px; flex-wrap: wrap; }
.guide-step { text-align: center; max-width: 240px; }
.guide-step-num {
    width: 56px; height: 56px; border-radius: 50%; margin: 0 auto 16px;
    display: flex; align-items: center; justify-content: center;
    background: linear-gradient(135deg, #2563eb, #0ea5e9); color: #fff;
    font-size: 1.4rem; font-weight: 800;
}
.guide-step h3 { font-size: 1.05rem; font-weight: 700; margin-bottom: 8px; color: #0f172a; }
.guide-step p { font-size: .9rem; color: #64748b; }
.guide-link { text-align: center; margin-top: 40px; }

/* ===== Download ===== */
.download { padding: 100px 0; }
.download-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.download-card {
    background: #fff; border: 2px solid #e2e8f0; border-radius: 16px; padding: 36px 24px;
    text-align: center; transition: border-color .3s, box-shadow .3s;
}
.download-card:hover { border-color: #2563eb; box-shadow: 0 8px 24px rgba(37,99,235,.1); }
.download-card-icon { font-size: 3rem; margin-bottom: 16px; }
.download-card h3 { font-size: 1.1rem; font-weight: 700; margin-bottom: 6px; color: #0f172a; }
.download-card .version { font-size: .82rem; color: #94a3b8; margin-bottom: 20px; }
.download-card .btn-primary { width: 100%; padding: 12px 0; font-size: .95rem; }
.download-note { text-align: center; margin-top: 32px; font-size: .88rem; color: #94a3b8; }

/* ===== Trust ===== */
.trust { padding: 100px 0; background: linear-gradient(160deg, #0f172a, #1e3a5f); color: #fff; }
.trust .section-title { color: #fff; }
.trust .section-subtitle { color: rgba(255,255,255,.6); }
.trust-stats { display: flex; justify-content: center; gap: 64px; flex-wrap: wrap; margin-bottom: 48px; }
.trust-stat { text-align: center; }
.trust-stat .num { font-size: 2.8rem; font-weight: 800; background: linear-gradient(90deg, #38bdf8, #818cf8); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }
.trust-stat .label { font-size: .95rem; color: rgba(255,255,255,.6); margin-top: 4px; }
.trust-badges { display: flex; justify-content: center; gap: 32px; flex-wrap: wrap; }
.trust-badge {
    display: flex; align-items: center; gap: 10px; padding: 12px 24px;
    background: rgba(255,255,255,.08); border-radius: 10px; border: 1px solid rgba(255,255,255,.1);
    color: rgba(255,255,255,.8); font-size: .9rem;
}
.trust-badge svg { width: 22px; height: 22px; fill: #38bdf8; }

/* ===== FAQ ===== */
.faq { padding: 100px 0; background: #f8fafc; }
.faq-list { max-width: 800px; margin: 0 auto; }
.faq-item { background: #fff; border-radius: 12px; margin-bottom: 16px; border: 1px solid #e2e8f0; overflow: hidden; }
.faq-question {
    display: block; padding: 20px 28px; font-size: 1.05rem; font-weight: 600;
    color: #0f172a; cursor: pointer; transition: background .2s;
}
.faq-question:hover { background: #f1f5f9; }
.faq-answer { padding: 0 28px 24px; }
.faq-answer p { font-size: .95rem; color: #475569; margin-bottom: 12px; line-height: 1.7; }
.faq-answer ol { padding-left: 20px; }
.faq-answer ol li { font-size: .93rem; color: #475569; margin-bottom: 8px; line-height: 1.6; list-style: decimal; }
.faq-category { font-size: .82rem; color: #2563eb; font-weight: 600; text-transform: uppercase; margin-bottom: 6px; display: block; padding: 20px 28px 0; }

/* ===== Footer ===== */
.site-footer { background: #0f172a; color: rgba(255,255,255,.7); padding: 64px 0 32px; }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 48px; margin-bottom: 48px; }
.footer-brand p { font-size: .9rem; line-height: 1.6; margin-top: 12px; color: rgba(255,255,255,.5); }
.footer-col h4 { font-size: .95rem; font-weight: 700; color: #fff; margin-bottom: 16px; }
.footer-col a { display: block; font-size: .88rem; color: rgba(255,255,255,.5); margin-bottom: 10px; transition: color .2s; }
.footer-col a:hover { color: #38bdf8; }
.footer-bottom { border-top: 1px solid rgba(255,255,255,.08); padding-top: 24px; display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 12px; }
.footer-bottom p { font-size: .82rem; color: rgba(255,255,255,.4); }

/* ===== Inner Page Hero ===== */
.page-hero {
    padding: 140px 24px 60px; text-align: center;
    background: linear-gradient(160deg, #0f172a, #1e3a5f);
    color: #fff;
}
.page-hero h1 { font-size: 2.4rem; font-weight: 800; margin-bottom: 12px; }
.page-hero p { font-size: 1.05rem; color: rgba(255,255,255,.65); max-width: 560px; margin: 0 auto; }

/* ===== Content Page ===== */
.content-page { padding: 80px 0; }
.content-block { max-width: 800px; margin: 0 auto; }
.content-block h2 { font-size: 1.5rem; font-weight: 700; color: #0f172a; margin: 40px 0 16px; }
.content-block h2:first-child { margin-top: 0; }
.content-block p { font-size: .98rem; color: #475569; line-height: 1.8; margin-bottom: 16px; }
.content-block ul { padding-left: 20px; margin-bottom: 16px; }
.content-block ul li { font-size: .95rem; color: #475569; margin-bottom: 8px; line-height: 1.6; list-style: disc; }

/* ===== Features Detail ===== */
.feature-detail { padding: 80px 0; }
.feature-row { display: flex; align-items: center; gap: 64px; margin-bottom: 80px; }
.feature-row:nth-child(even) { flex-direction: row-reverse; }
.feature-text { flex: 1; }
.feature-text h2 { font-size: 1.8rem; font-weight: 700; color: #0f172a; margin-bottom: 16px; }
.feature-text p { font-size: 1rem; color: #64748b; line-height: 1.7; margin-bottom: 12px; }
.feature-visual {
    flex: 1; border-radius: 20px; padding: 48px; display: flex; align-items: center; justify-content: center;
    font-size: 5rem; min-height: 280px;
}
.feature-visual.v1 { background: linear-gradient(135deg, #eff6ff, #dbeafe); }
.feature-visual.v2 { background: linear-gradient(135deg, #f0fdf4, #dcfce7); }
.feature-visual.v3 { background: linear-gradient(135deg, #fef3c7, #fde68a); }
.feature-visual.v4 { background: linear-gradient(135deg, #fce7f3, #fbcfe8); }

/* ===== Responsive ===== */
@media (max-width: 1024px) {
    .highlights-grid, .scenarios-grid, .download-grid { grid-template-columns: repeat(2, 1fr); }
    .footer-grid { grid-template-columns: 1fr 1fr; }
    .feature-row, .feature-row:nth-child(even) { flex-direction: column; }
}
@media (max-width: 768px) {
    .nav-links { display: none; }
    .hamburger { display: flex; }
    .nav-links.open {
        display: flex; flex-direction: column; position: absolute; top: 68px; left: 0; width: 100%;
        background: #fff; padding: 24px; gap: 16px; border-bottom: 1px solid #e2e8f0;
        box-shadow: 0 8px 24px rgba(0,0,0,.08);
    }
    .hero h1 { font-size: 2.2rem; }
    .hero p { font-size: 1rem; }
    .highlights-grid, .scenarios-grid, .download-grid { grid-template-columns: 1fr; }
    .trust-stats { gap: 32px; }
    .footer-grid { grid-template-columns: 1fr; gap: 32px; }
    .guide-steps { flex-direction: column; align-items: center; }
    .section-title { font-size: 1.6rem; }
    .page-hero h1 { font-size: 1.8rem; }
}