/* === 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; line-height: 1.6; background: #fff;
}
a { text-decoration: none; color: inherit; transition: color .3s; }
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(255,255,255,0.95); backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(0,0,0,0.06);
    transition: background .3s, box-shadow .3s;
}
.site-header.scrolled { background: #fff; box-shadow: 0 2px 20px rgba(0,0,0,0.08); }
.nav-inner {
    display: flex; align-items: center; justify-content: space-between;
    max-width: 1200px; margin: 0 auto; padding: 0 20px; height: 70px;
}
.logo { display: flex; align-items: center; gap: 10px; font-size: 1.4rem; font-weight: 700; color: #1a56db; }
.logo-icon {
    width: 36px; height: 36px; background: linear-gradient(135deg, #1a56db, #06b6d4);
    border-radius: 10px; display: flex; align-items: center; justify-content: center;
    color: #fff; font-weight: 900; font-size: 1.1rem;
}
.nav-menu { display: flex; gap: 32px; align-items: center; }
.nav-menu a { font-size: 0.95rem; color: #555; font-weight: 500; padding: 6px 0; position: relative; }
.nav-menu a:hover, .nav-menu a.active { color: #1a56db; }
.nav-menu a.active::after {
    content: ''; position: absolute; bottom: -2px; left: 0; right: 0;
    height: 2px; background: #1a56db; border-radius: 1px;
}
.nav-cta {
    display: inline-block; padding: 10px 24px; background: linear-gradient(135deg, #1a56db, #06b6d4);
    color: #fff !important; border-radius: 8px; font-weight: 600; font-size: 0.9rem;
    transition: transform .2s, box-shadow .2s;
}
.nav-cta:hover { transform: translateY(-1px); box-shadow: 0 4px 15px rgba(26,86,219,0.4); }

/* Mobile menu */
.menu-toggle { display: none; flex-direction: column; gap: 5px; cursor: pointer; padding: 5px; }
.menu-toggle span { width: 24px; height: 2px; background: #333; border-radius: 2px; transition: .3s; }

@media (max-width: 768px) {
    .menu-toggle { display: flex; }
    .nav-menu {
        position: fixed; top: 70px; left: 0; right: 0; background: #fff;
        flex-direction: column; gap: 0; padding: 20px;
        box-shadow: 0 10px 30px rgba(0,0,0,0.1);
        transform: translateY(-120%); transition: transform .3s;
    }
    .nav-menu.open { transform: translateY(0); }
    .nav-menu a { padding: 14px 0; border-bottom: 1px solid #f0f0f0; width: 100%; }
    .nav-cta { margin-top: 10px; text-align: center; }
}

/* === Hero === */
.hero {
    padding: 160px 20px 100px; text-align: center;
    background: linear-gradient(180deg, #f0f5ff 0%, #fff 100%);
    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(26,86,219,0.05) 0%, transparent 50%),
                radial-gradient(circle at 70% 50%, rgba(6,182,212,0.05) 0%, transparent 50%);
}
.hero-content { position: relative; z-index: 1; max-width: 800px; margin: 0 auto; }
.hero h1 { font-size: 3rem; font-weight: 800; color: #111; margin-bottom: 20px; line-height: 1.2; }
.hero h1 span { color: #1a56db; }
.hero .subtitle { font-size: 1.2rem; color: #666; margin-bottom: 40px; line-height: 1.8; }
.hero-cta {
    display: inline-block; padding: 16px 48px;
    background: linear-gradient(135deg, #1a56db, #06b6d4);
    color: #fff; font-size: 1.15rem; font-weight: 700; border-radius: 12px;
    transition: transform .2s, box-shadow .2s;
    box-shadow: 0 4px 20px rgba(26,86,219,0.3);
}
.hero-cta:hover { transform: translateY(-2px); box-shadow: 0 8px 30px rgba(26,86,219,0.4); }
.trust-badges { display: flex; gap: 24px; justify-content: center; margin-top: 30px; flex-wrap: wrap; }
.trust-badge {
    display: flex; align-items: center; gap: 6px;
    font-size: 0.85rem; color: #888; background: rgba(255,255,255,0.8);
    padding: 6px 14px; border-radius: 20px; border: 1px solid #e8e8e8;
}
.trust-badge .badge-icon { color: #1a56db; font-weight: 700; }

@media (max-width: 768px) {
    .hero { padding: 120px 20px 60px; }
    .hero h1 { font-size: 2rem; }
    .hero .subtitle { font-size: 1rem; }
}

/* === Section Common === */
.section { padding: 80px 20px; }
.section-alt { background: #f8fafc; }
.section-title { text-align: center; margin-bottom: 60px; }
.section-title h2 { font-size: 2rem; font-weight: 700; color: #111; margin-bottom: 12px; }
.section-title p { font-size: 1.05rem; color: #888; }

/* === Features Grid === */
.features-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 30px; max-width: 1200px; margin: 0 auto; }
.feature-card {
    text-align: center; padding: 40px 24px; background: #fff; border-radius: 16px;
    border: 1px solid #eef2f7; transition: transform .3s, box-shadow .3s;
}
.feature-card:hover { transform: translateY(-4px); box-shadow: 0 12px 40px rgba(0,0,0,0.08); }
.feature-icon {
    width: 64px; height: 64px; margin: 0 auto 20px;
    background: linear-gradient(135deg, #eef2ff, #e0f2fe);
    border-radius: 16px; display: flex; align-items: center; justify-content: center;
    font-size: 1.8rem;
}
.feature-card h3 { font-size: 1.15rem; font-weight: 700; color: #111; margin-bottom: 10px; }
.feature-card p { font-size: 0.9rem; color: #888; line-height: 1.6; }

@media (max-width: 768px) {
    .features-grid { grid-template-columns: repeat(2, 1fr); gap: 16px; }
    .feature-card { padding: 24px 16px; }
}

/* === Scenes === */
.scenes-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; max-width: 1200px; margin: 0 auto; }
.scene-card {
    background: #fff; border-radius: 16px; overflow: hidden;
    border: 1px solid #eef2f7; transition: transform .3s, box-shadow .3s;
}
.scene-card:hover { transform: translateY(-4px); box-shadow: 0 12px 40px rgba(0,0,0,0.08); }
.scene-img {
    height: 160px; display: flex; align-items: center; justify-content: center;
    font-size: 3rem; background: linear-gradient(135deg, #eef2ff, #e0f2fe);
}
.scene-card:nth-child(2) .scene-img { background: linear-gradient(135deg, #fef3c7, #fde68a); }
.scene-card:nth-child(3) .scene-img { background: linear-gradient(135deg, #d1fae5, #a7f3d0); }
.scene-card:nth-child(4) .scene-img { background: linear-gradient(135deg, #fce7f3, #fbcfe8); }
.scene-body { padding: 24px; }
.scene-body h3 { font-size: 1.1rem; font-weight: 700; margin-bottom: 8px; color: #111; }
.scene-body p { font-size: 0.9rem; color: #888; }

@media (max-width: 768px) {
    .scenes-grid { grid-template-columns: repeat(2, 1fr); gap: 16px; }
}

/* === Guide Steps === */
.steps { display: flex; gap: 40px; justify-content: center; max-width: 900px; margin: 0 auto; flex-wrap: wrap; }
.step {
    flex: 1; min-width: 200px; text-align: center; position: relative;
}
.step-num {
    width: 56px; height: 56px; margin: 0 auto 16px;
    background: linear-gradient(135deg, #1a56db, #06b6d4);
    border-radius: 50%; display: flex; align-items: center; justify-content: center;
    color: #fff; font-size: 1.4rem; font-weight: 800;
}
.step h3 { font-size: 1.05rem; font-weight: 700; margin-bottom: 8px; color: #111; }
.step p { font-size: 0.9rem; color: #888; }
.step-arrow {
    position: absolute; right: -30px; top: 28px; font-size: 1.5rem; color: #ccc;
}
@media (max-width: 768px) {
    .step-arrow { display: none; }
    .steps { flex-direction: column; gap: 24px; }
}

/* === Download === */
.download-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; max-width: 1000px; margin: 0 auto; }
.download-card {
    text-align: center; padding: 36px 20px; background: #fff; border-radius: 16px;
    border: 1px solid #eef2f7; transition: transform .3s, box-shadow .3s;
}
.download-card:hover { transform: translateY(-4px); box-shadow: 0 12px 40px rgba(0,0,0,0.08); }
.download-icon { font-size: 2.5rem; margin-bottom: 16px; }
.download-card h3 { font-size: 1.05rem; font-weight: 700; margin-bottom: 6px; color: #111; }
.download-card .version { font-size: 0.8rem; color: #aaa; margin-bottom: 16px; }
.download-btn {
    display: inline-block; padding: 10px 28px;
    background: linear-gradient(135deg, #1a56db, #06b6d4);
    color: #fff; border-radius: 8px; font-weight: 600; font-size: 0.9rem;
    transition: transform .2s, box-shadow .2s;
}
.download-btn:hover { transform: translateY(-1px); box-shadow: 0 4px 15px rgba(26,86,219,0.3); }
.download-notice { text-align: center; margin-top: 30px; font-size: 0.85rem; color: #f59e0b; }

@media (max-width: 768px) {
    .download-grid { grid-template-columns: repeat(2, 1fr); gap: 16px; }
}

/* === Trust === */
.trust-section { background: linear-gradient(135deg, #1a56db, #06b6d4); color: #fff; }
.trust-section .section-title h2 { color: #fff; }
.trust-section .section-title p { color: rgba(255,255,255,0.7); }
.trust-stats { display: flex; gap: 60px; justify-content: center; flex-wrap: wrap; margin-bottom: 50px; }
.trust-stat { text-align: center; }
.trust-stat .num { font-size: 2.5rem; font-weight: 800; }
.trust-stat .label { font-size: 0.9rem; opacity: 0.8; margin-top: 4px; }
.trust-badges-row { display: flex; gap: 30px; justify-content: center; flex-wrap: wrap; }
.trust-badge-item {
    display: flex; align-items: center; gap: 8px;
    background: rgba(255,255,255,0.15); padding: 10px 20px; border-radius: 10px;
    font-size: 0.9rem;
}

/* === FAQ === */
.faq-list { max-width: 800px; margin: 0 auto; }
.faq-item {
    background: #fff; border-radius: 12px; margin-bottom: 16px;
    border: 1px solid #eef2f7; overflow: hidden;
}
.faq-question {
    padding: 20px 24px; font-weight: 700; font-size: 1rem; color: #111;
    border-bottom: 1px solid #f0f0f0; display: flex; align-items: center; gap: 10px;
}
.faq-question .q-icon {
    width: 28px; height: 28px; background: linear-gradient(135deg, #1a56db, #06b6d4);
    border-radius: 50%; display: flex; align-items: center; justify-content: center;
    color: #fff; font-size: 0.8rem; font-weight: 800; flex-shrink: 0;
}
.faq-answer { padding: 20px 24px; }
.faq-answer p { font-size: 0.92rem; color: #555; line-height: 1.8; margin-bottom: 8px; }
.faq-answer ol { padding-left: 20px; }
.faq-answer ol li { font-size: 0.92rem; color: #555; line-height: 1.8; margin-bottom: 4px; list-style: decimal; }

/* === Footer === */
.site-footer { background: #111827; color: #9ca3af; padding: 60px 20px 30px; }
.footer-inner { max-width: 1200px; margin: 0 auto; }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 40px; margin-bottom: 40px; }
.footer-brand .logo { color: #fff; margin-bottom: 12px; }
.footer-brand p { font-size: 0.85rem; line-height: 1.7; }
.footer-col h4 { color: #fff; font-size: 0.95rem; margin-bottom: 16px; }
.footer-col a { display: block; font-size: 0.85rem; color: #9ca3af; padding: 4px 0; transition: color .2s; }
.footer-col a:hover { color: #fff; }
.footer-bottom {
    border-top: 1px solid #1f2937; padding-top: 20px;
    display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 10px;
    font-size: 0.8rem;
}

@media (max-width: 768px) {
    .footer-grid { grid-template-columns: 1fr 1fr; gap: 24px; }
    .footer-bottom { flex-direction: column; text-align: center; }
}

/* === Page Header (for inner pages) === */
.page-header {
    padding: 140px 20px 60px; text-align: center;
    background: linear-gradient(180deg, #f0f5ff 0%, #fff 100%);
}
.page-header h1 { font-size: 2.2rem; font-weight: 800; color: #111; margin-bottom: 12px; }
.page-header p { font-size: 1.05rem; color: #888; }

/* === Content Block === */
.content-block { max-width: 800px; margin: 0 auto; }
.content-block h2 { font-size: 1.5rem; font-weight: 700; color: #111; margin: 40px 0 16px; }
.content-block h3 { font-size: 1.2rem; font-weight: 600; color: #333; margin: 30px 0 12px; }
.content-block p { font-size: 0.95rem; color: #555; line-height: 1.8; margin-bottom: 16px; }
.content-block ul { padding-left: 20px; margin-bottom: 16px; }
.content-block ul li { font-size: 0.95rem; color: #555; line-height: 1.8; margin-bottom: 6px; list-style: disc; }

/* === Guide Detail === */
.guide-detail { max-width: 800px; margin: 0 auto; }
.guide-step-detail {
    background: #fff; border-radius: 16px; padding: 36px;
    border: 1px solid #eef2f7; margin-bottom: 24px;
}
.guide-step-detail .step-header { display: flex; align-items: center; gap: 16px; margin-bottom: 16px; }
.guide-step-detail .step-header .step-num { margin: 0; }
.guide-step-detail .step-header h3 { font-size: 1.2rem; font-weight: 700; color: #111; }
.guide-step-detail p { font-size: 0.95rem; color: #555; line-height: 1.8; }
.guide-step-detail ul { padding-left: 20px; margin-top: 12px; }
.guide-step-detail ul li { font-size: 0.95rem; color: #555; line-height: 1.8; margin-bottom: 6px; list-style: disc; }

/* === Download Page Detail === */
.download-detail-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 30px; max-width: 900px; margin: 0 auto; }
.download-detail-card {
    background: #fff; border-radius: 16px; padding: 36px; text-align: center;
    border: 1px solid #eef2f7; transition: transform .3s, box-shadow .3s;
}
.download-detail-card:hover { transform: translateY(-4px); box-shadow: 0 12px 40px rgba(0,0,0,0.08); }
.download-detail-card .platform-icon { font-size: 3rem; margin-bottom: 16px; }
.download-detail-card h3 { font-size: 1.2rem; font-weight: 700; margin-bottom: 8px; }
.download-detail-card .platform-desc { font-size: 0.9rem; color: #888; margin-bottom: 16px; }
.download-detail-card .version-info { font-size: 0.8rem; color: #aaa; margin-bottom: 20px; }

@media (max-width: 768px) {
    .download-detail-grid { grid-template-columns: 1fr; }
}

/* === About Page === */
.about-content { max-width: 800px; margin: 0 auto; }
.about-values { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; margin: 40px 0; }
.about-value {
    text-align: center; padding: 30px 20px; background: #fff;
    border-radius: 16px; border: 1px solid #eef2f7;
}
.about-value .value-icon { font-size: 2rem; margin-bottom: 12px; }
.about-value h3 { font-size: 1.05rem; font-weight: 700; margin-bottom: 8px; color: #111; }
.about-value p { font-size: 0.85rem; color: #888; }

@media (max-width: 768px) {
    .about-values { grid-template-columns: 1fr; }
}

/* === Legal Pages === */
.legal-content { max-width: 800px; margin: 0 auto; }
.legal-content h2 { font-size: 1.3rem; font-weight: 700; color: #111; margin: 36px 0 12px; }
.legal-content h3 { font-size: 1.1rem; font-weight: 600; color: #333; margin: 24px 0 10px; }
.legal-content p { font-size: 0.95rem; color: #555; line-height: 1.8; margin-bottom: 14px; }
.legal-content ul { padding-left: 20px; margin-bottom: 14px; }
.legal-content ul li { font-size: 0.95rem; color: #555; line-height: 1.8; margin-bottom: 6px; list-style: disc; }
.legal-update { font-size: 0.85rem; color: #aaa; margin-bottom: 30px; }

/* === Scroll Animation === */
.fade-in { opacity: 0; transform: translateY(20px); transition: opacity .6s, transform .6s; }
.fade-in.visible { opacity: 1; transform: translateY(0); }