:root {
  --bg: #ffffff;
  --bg-alt: #f6f7f9;
  --bg-dark: #0f1729;
  --text: #0f172a;
  --muted: #5b6474;
  --border: #e6e8ec;
  --accent: #1f6feb;
  --accent-dark: #1858c4;
  --accent-soft: #eaf1fe;
  --radius: 14px;
  --shadow: 0 1px 2px rgba(15, 23, 42, .04), 0 8px 24px rgba(15, 23, 42, .06);
  --font: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Segoe UI", Roboto, sans-serif;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; scroll-padding-top: 80px; }
body { font-family: var(--font); color: var(--text); background: var(--bg); line-height: 1.7; -webkit-font-smoothing: antialiased; }
a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; }
img { max-width: 100%; display: block; }

.container { width: 100%; max-width: 1160px; margin: 0 auto; padding: 0 24px; }
.container.narrow { max-width: 820px; }

/* buttons */
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 8px; font-weight: 600; border-radius: 10px; border: 1px solid transparent; cursor: pointer; transition: background .15s, border-color .15s, color .15s, transform .15s; font-size: 15px; padding: 10px 18px; font-family: inherit; white-space: nowrap; }
.btn:active { transform: translateY(1px); }
.btn-sm { font-size: 14px; padding: 8px 14px; }
.btn-lg { font-size: 16px; padding: 14px 24px; }
.btn-block { width: 100%; }
.btn-primary { background: var(--accent); color: #fff; }
.btn-primary:hover { background: var(--accent-dark); }
.btn-ghost { background: #fff; color: var(--text); border-color: var(--border); }
.btn-ghost:hover { border-color: #c9ced6; background: var(--bg-alt); }
.btn-light { background: #fff; color: var(--accent); }
.btn-light:hover { background: #f0f5ff; }
.btn.is-disabled { opacity: .75; cursor: default; pointer-events: none; }

/* header */
.site-header { position: sticky; top: 0; z-index: 50; background: rgba(255, 255, 255, .9); backdrop-filter: saturate(180%) blur(12px); border-bottom: 1px solid transparent; transition: border-color .2s; }
.site-header.scrolled { border-bottom-color: var(--border); }
.header-inner { display: flex; align-items: center; height: 68px; gap: 32px; }
.logo { display: inline-flex; align-items: center; gap: 10px; font-weight: 700; font-size: 18px; }
.logo-mark { width: 32px; height: 32px; border-radius: 9px; background: var(--accent); color: #fff; display: grid; place-items: center; font-size: 16px; }
.nav { display: flex; gap: 28px; margin-left: auto; }
.nav a { color: var(--muted); font-size: 15px; transition: color .15s; }
.nav a:hover { color: var(--text); }
.nav-toggle { display: none; background: none; border: 0; width: 40px; height: 40px; cursor: pointer; flex-direction: column; justify-content: center; gap: 6px; padding: 0 9px; }
.nav-toggle span { display: block; height: 2px; background: var(--text); border-radius: 2px; transition: transform .2s; }
.nav-open .nav-toggle span:first-child { transform: translateY(4px) rotate(45deg); }
.nav-open .nav-toggle span:last-child { transform: translateY(-4px) rotate(-45deg); }

/* hero */
.hero { padding: 72px 0 64px; background: radial-gradient(900px 420px at 85% 0%, #eef4ff 0%, rgba(255, 255, 255, 0) 70%); }
.hero-inner { display: grid; grid-template-columns: 1.15fr .85fr; gap: 56px; align-items: center; }
.eyebrow { color: var(--accent); font-weight: 600; font-size: 14px; letter-spacing: .02em; margin-bottom: 14px; }
.hero h1 { font-size: 48px; line-height: 1.22; letter-spacing: -.01em; font-weight: 800; margin-bottom: 20px; }
.accent { color: var(--accent); }
.lead { font-size: 18px; color: var(--muted); max-width: 600px; margin-bottom: 32px; }
.hero-actions { display: flex; gap: 12px; flex-wrap: wrap; margin-bottom: 24px; }
.hero-points { display: flex; flex-wrap: wrap; gap: 8px 22px; color: var(--muted); font-size: 14px; }
.hero-points li::before { content: ""; display: inline-block; width: 6px; height: 6px; border-radius: 50%; background: #22a06b; margin-right: 8px; vertical-align: middle; }

/* phone chat mock */
.phone { max-width: 360px; margin-left: auto; background: #fff; border: 1px solid var(--border); border-radius: 28px; box-shadow: 0 30px 60px -20px rgba(15, 23, 42, .25); overflow: hidden; }
.phone-head { display: flex; align-items: center; gap: 12px; padding: 16px 18px; border-bottom: 1px solid var(--border); }
.avatar { width: 38px; height: 38px; border-radius: 50%; background: var(--accent); color: #fff; display: grid; place-items: center; font-weight: 700; }
.chat-name { font-weight: 600; font-size: 15px; line-height: 1.2; }
.chat-sub { color: var(--muted); font-size: 12px; }
.chat { padding: 18px; display: flex; flex-direction: column; gap: 8px; background: #eef2f6; min-height: 420px; }
.msg { max-width: 82%; padding: 9px 13px; border-radius: 14px; font-size: 14px; line-height: 1.55; }
.msg.bot { background: #fff; align-self: flex-start; border-bottom-left-radius: 4px; }
.msg.user { background: #d8ebff; align-self: flex-end; border-bottom-right-radius: 4px; }
.kb { display: flex; flex-wrap: wrap; gap: 6px; max-width: 90%; }
.kb span { background: rgba(255, 255, 255, .75); border: 1px solid #d7dde5; color: var(--accent); font-size: 13px; padding: 5px 11px; border-radius: 8px; }

/* trust */
.trust { border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }
.trust-grid { display: grid; grid-template-columns: repeat(5, 1fr); }
.trust-grid > div { padding: 26px 12px; text-align: center; border-right: 1px solid var(--border); }
.trust-grid > div:last-child { border-right: 0; }
.trust strong { display: block; font-size: 28px; font-weight: 800; color: var(--accent); line-height: 1.2; }
.trust span { color: var(--muted); font-size: 14px; }

/* sections */
.section { padding: 96px 0; }
.section-alt { background: var(--bg-alt); }
.section-head { max-width: 720px; margin-bottom: 48px; }
.section-head h2 { font-size: 34px; line-height: 1.3; font-weight: 800; margin-bottom: 14px; }
.section-head p:not(.eyebrow) { color: var(--muted); font-size: 17px; }

.cards-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.card { background: #fff; border: 1px solid var(--border); border-radius: var(--radius); padding: 28px; }
.card h3 { font-size: 19px; margin-bottom: 8px; line-height: 1.4; }
.card > p { color: var(--muted); font-size: 15px; }

.service { display: flex; flex-direction: column; }
.service.featured { border-color: var(--accent); box-shadow: var(--shadow); }
.service-icon { width: 44px; height: 44px; border-radius: 12px; background: var(--accent-soft); color: var(--accent); display: grid; place-items: center; font-weight: 800; margin-bottom: 18px; }
.checks { margin: 18px 0; display: grid; gap: 8px; }
.checks li { position: relative; padding-left: 24px; font-size: 15px; }
.checks li::before { content: ""; position: absolute; left: 2px; top: 8px; width: 11px; height: 6px; border-left: 2px solid var(--accent); border-bottom: 2px solid var(--accent); transform: rotate(-45deg); }
.card > .meta { margin-top: auto; padding-top: 16px; border-top: 1px solid var(--border); font-weight: 600; color: var(--text); display: flex; justify-content: space-between; gap: 12px; }
.meta a { color: var(--accent); font-weight: 500; }
.meta a:hover { text-decoration: underline; }

.problems .card h3 { font-size: 18px; }

/* steps */
.steps { display: grid; grid-template-columns: repeat(5, 1fr); gap: 16px; counter-reset: step; }
.steps li { position: relative; padding: 24px 20px; border: 1px solid var(--border); border-radius: var(--radius); background: #fff; display: flex; flex-direction: column; }
.step-no { font-size: 13px; font-weight: 700; color: var(--accent); margin-bottom: 10px; }
.steps h3 { font-size: 17px; margin-bottom: 8px; }
.steps p { color: var(--muted); font-size: 14px; margin-bottom: 16px; }
.step-time { margin-top: auto; font-size: 13px; color: var(--muted); background: var(--bg-alt); padding: 3px 10px; border-radius: 999px; align-self: flex-start; }

/* pricing */
.tabs { display: inline-flex; background: #fff; border: 1px solid var(--border); border-radius: 12px; padding: 4px; margin-bottom: 28px; }
.tab { border: 0; background: none; font: inherit; font-size: 15px; font-weight: 600; color: var(--muted); padding: 9px 20px; border-radius: 9px; cursor: pointer; transition: background .15s, color .15s; }
.tab.active { background: var(--accent); color: #fff; }
.tab-panel { display: none; }
.tab-panel.active { display: block; }
.price { position: relative; display: flex; flex-direction: column; }
.price.popular { border-color: var(--accent); box-shadow: var(--shadow); }
.badge { position: absolute; top: -12px; left: 28px; background: var(--accent); color: #fff; font-size: 12px; font-weight: 600; padding: 3px 10px; border-radius: 999px; }
.card > .plan-time { font-size: 28px; font-weight: 800; color: var(--text); line-height: 1.3; margin-top: 6px; }
.plan-time small { display: block; font-size: 13px; font-weight: 500; color: var(--muted); }
.card > .price-sub { font-size: 14px; }
.price .checks { flex: 1; }
.addons { margin-top: 24px; background: #fff; border: 1px solid var(--border); border-radius: var(--radius); padding: 24px 28px; }
.addons h4 { font-size: 16px; margin-bottom: 12px; }
.addons ul { display: grid; grid-template-columns: 1fr 1fr; gap: 0 40px; }
.addons li { display: flex; justify-content: space-between; gap: 16px; padding: 10px 0; border-bottom: 1px dashed var(--border); font-size: 15px; }
.addons li span { color: var(--text); }
.addons li b { color: var(--muted); font-weight: 500; }
.note { margin-top: 24px; color: var(--muted); font-size: 14px; }

/* demos */
.demo-chat, .demo-shop { background: #eef2f6; border-radius: 12px; padding: 16px; margin-bottom: 20px; display: flex; flex-direction: column; gap: 8px; min-height: 132px; justify-content: center; }
.demo-chat .msg { max-width: 100%; }
.shop-item { display: flex; align-items: center; gap: 10px; background: #fff; border-radius: 10px; padding: 9px 12px; font-size: 14px; }
.shop-item i { width: 28px; height: 28px; border-radius: 8px; background: var(--accent-soft); }
.shop-item b { margin-left: auto; }
.shop-btn { background: var(--accent); color: #fff; text-align: center; border-radius: 10px; padding: 8px; font-size: 14px; font-weight: 600; }
.tags { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 16px; }
.tags span { font-size: 12px; color: var(--accent); background: var(--accent-soft); padding: 3px 10px; border-radius: 999px; }

/* ownership */
.section-dark { background: var(--bg-dark); color: #e6e9f0; }
.section-head.light h2 { color: #fff; }
.section-head.light p:not(.eyebrow) { color: #a3acbd; }
.section-dark .eyebrow { color: #6ea8ff; }
.own-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
.own-item { border: 1px solid #253048; border-radius: var(--radius); padding: 26px; background: #141e33; }
.own-item h3 { color: #fff; font-size: 17px; margin-bottom: 10px; }
.own-item p { color: #a3acbd; font-size: 14px; }

/* faq */
.faq { display: grid; gap: 12px; }
.faq details { border: 1px solid var(--border); border-radius: 12px; padding: 0 22px; background: #fff; }
.faq summary { cursor: pointer; list-style: none; font-weight: 600; font-size: 16px; padding: 18px 28px 18px 0; position: relative; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; position: absolute; right: 0; top: 50%; transform: translateY(-50%); font-size: 22px; color: var(--muted); font-weight: 400; }
.faq details[open] summary::after { content: "−"; }
.faq details p { color: var(--muted); padding-bottom: 20px; font-size: 15px; }

/* notes */
.note-card { transition: border-color .15s, transform .15s; display: block; }
.note-card:hover { border-color: var(--accent); transform: translateY(-2px); }
.note-tag { display: inline-block; font-size: 12px; color: var(--accent); background: var(--accent-soft); padding: 2px 10px; border-radius: 999px; margin-bottom: 14px; }
.note-card h3 { font-size: 17px; }

/* final cta */
.cta-final { background: var(--accent); color: #fff; padding: 72px 0; }
.cta-inner { display: flex; align-items: center; justify-content: space-between; gap: 40px; }
.cta-final h2 { font-size: 30px; line-height: 1.35; margin-bottom: 10px; }
.cta-final p { color: #d6e4ff; margin-bottom: 20px; }
/* footer */
.site-footer { background: var(--bg-alt); border-top: 1px solid var(--border); padding: 56px 0 28px; }
.footer-inner { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 40px; }
.footer-inner p { color: var(--muted); font-size: 14px; margin-top: 14px; max-width: 360px; }
.footer-inner h4 { font-size: 14px; margin-bottom: 12px; }
.footer-inner > div > a:not(.logo) { display: block; color: var(--muted); font-size: 14px; margin-bottom: 8px; }
.footer-inner > div > a:not(.logo):hover { color: var(--text); }
.footer-bottom { margin-top: 40px; padding-top: 20px; border-top: 1px solid var(--border); color: var(--muted); font-size: 13px; }

.float-tg { display: none; }

.toast { position: fixed; left: 50%; bottom: 32px; transform: translate(-50%, 16px); background: #111827; color: #fff; font-size: 14px; padding: 12px 18px; border-radius: 10px; box-shadow: 0 8px 24px rgba(0, 0, 0, .18); opacity: 0; pointer-events: none; transition: opacity .2s, transform .2s; z-index: 1000; max-width: calc(100% - 32px); text-align: center; }
.toast.show { opacity: 1; transform: translate(-50%, 0); }

/* service pages */
.nav a.current { color: var(--text); font-weight: 600; }
.page-hero { padding: 72px 0 56px; background: radial-gradient(900px 380px at 80% 0%, #eef4ff 0%, rgba(255, 255, 255, 0) 70%); border-bottom: 1px solid var(--border); }
.page-hero h1 { font-size: 44px; line-height: 1.25; font-weight: 800; margin-bottom: 18px; }
.page-hero .lead { max-width: 720px; }

.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
.mini { display: flex; flex-direction: column; padding: 24px; }
.mini h3 { font-size: 17px; }
.card > .mini-meta, .mini-meta { margin-top: auto; padding-top: 16px; font-size: 14px; font-weight: 600; color: var(--accent); }

.compare { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.compare-col.featured { border-color: var(--accent); box-shadow: var(--shadow); }
.card > .compare-foot { font-weight: 600; color: var(--text); border-top: 1px solid var(--border); padding-top: 14px; }

.two-col { display: grid; grid-template-columns: 1fr 1fr; gap: 64px; align-items: start; }
.h2 { font-size: 28px; line-height: 1.35; font-weight: 800; margin-bottom: 20px; }
.muted { color: var(--muted); margin-bottom: 18px; }
.prep { display: grid; gap: 12px; counter-reset: prep; }
.prep li { counter-increment: prep; display: grid; grid-template-columns: 36px 1fr; column-gap: 12px; padding: 16px 18px; border: 1px solid var(--border); border-radius: 12px; }
.prep li::before { content: counter(prep); grid-row: span 2; width: 32px; height: 32px; border-radius: 50%; background: var(--accent-soft); color: var(--accent); display: grid; place-items: center; font-weight: 700; font-size: 14px; }
.prep b { font-size: 16px; }
.prep span { color: var(--muted); font-size: 14px; }
.chips { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 24px; }
.chips span { font-size: 13px; padding: 5px 12px; border-radius: 999px; background: var(--bg-alt); border: 1px solid var(--border); }
.host { display: grid; gap: 10px; }
.host li { display: flex; justify-content: space-between; gap: 16px; padding: 12px 0; border-bottom: 1px dashed var(--border); font-size: 15px; }
.host span { color: var(--muted); text-align: right; }
.accept { display: grid; gap: 12px; }
.accept li { position: relative; padding: 16px 18px 16px 48px; border: 1px solid #253048; border-radius: 12px; background: #141e33; color: #d5dbe6; font-size: 15px; }
.accept li::before { content: ""; position: absolute; left: 20px; top: 22px; width: 12px; height: 6px; border-left: 2px solid #6ea8ff; border-bottom: 2px solid #6ea8ff; transform: rotate(-45deg); }
.steps.steps-4 { grid-template-columns: repeat(4, 1fr); }

/* article page */
.article-hero { padding: 64px 0 32px; }
.article-hero h1 { font-size: 40px; line-height: 1.3; margin-bottom: 12px; }
.article-hero p { color: var(--muted); font-size: 17px; }
.toc { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 24px; }
.toc a { border: 1px solid var(--border); border-radius: 999px; padding: 6px 14px; font-size: 14px; color: var(--muted); }
.toc a:hover { border-color: var(--accent); color: var(--accent); }
.article { padding: 48px 0; border-top: 1px solid var(--border); }
.article h2 { font-size: 28px; line-height: 1.35; margin-bottom: 8px; }
.article .date { color: var(--muted); font-size: 14px; margin-bottom: 24px; }
.article h3 { font-size: 19px; margin: 28px 0 10px; }
.article p { margin-bottom: 14px; color: #273142; }
.article ul.dot { margin: 0 0 14px 0; display: grid; gap: 6px; }
.article ul.dot li { position: relative; padding-left: 18px; color: #273142; }
.article ul.dot li::before { content: ""; position: absolute; left: 2px; top: 11px; width: 6px; height: 6px; border-radius: 50%; background: var(--accent); }
.article table { width: 100%; border-collapse: collapse; margin: 8px 0 18px; font-size: 15px; }
.article th, .article td { border: 1px solid var(--border); padding: 10px 14px; text-align: left; vertical-align: top; }
.article th { background: var(--bg-alt); }
.article-cta { margin-top: 24px; padding: 20px 24px; border-radius: 12px; background: var(--accent-soft); display: flex; align-items: center; justify-content: space-between; gap: 16px; flex-wrap: wrap; }
.article-cta p { margin: 0; color: var(--text); font-weight: 600; }

/* responsive */
@media (max-width: 1024px) {
  .hero h1 { font-size: 40px; }
  .steps { grid-template-columns: repeat(3, 1fr); }
  .steps.steps-4 { grid-template-columns: repeat(2, 1fr); }
  .own-grid { grid-template-columns: repeat(2, 1fr); }
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .two-col { gap: 40px; }
}

@media (max-width: 860px) {
  .nav { position: fixed; inset: 68px 0 auto 0; background: #fff; flex-direction: column; gap: 0; padding: 8px 24px 20px; border-bottom: 1px solid var(--border); display: none; }
  .nav a { padding: 12px 0; border-bottom: 1px solid var(--border); font-size: 16px; color: var(--text); }
  .nav-open .nav { display: flex; }
  .nav-toggle { display: flex; margin-left: auto; }
  .header-cta { display: none; }
  .hero { padding: 48px 0; }
  .hero-inner { grid-template-columns: 1fr; gap: 40px; }
  .hero h1 { font-size: 32px; }
  .lead { font-size: 16px; }
  .phone { margin: 0 auto; }
  .chat { min-height: auto; }
  .trust-grid { grid-template-columns: repeat(3, 1fr); }
  .trust-grid > div { border-bottom: 1px solid var(--border); }
  .trust-grid > div:nth-child(3) { border-right: 0; }
  .trust-grid > div:nth-child(n+4) { border-bottom: 0; }
  .section { padding: 64px 0; }
  .section-head h2 { font-size: 26px; }
  .cards-3 { grid-template-columns: 1fr; }
  .steps, .steps.steps-4 { grid-template-columns: 1fr; }
  .addons ul { grid-template-columns: 1fr; }
  .page-hero { padding: 48px 0 40px; }
  .page-hero h1 { font-size: 32px; }
  .grid-4, .compare, .two-col { grid-template-columns: 1fr; }
  .h2 { font-size: 24px; }
  .tabs { display: flex; width: 100%; }
  .tab { flex: 1; padding: 9px 8px; }
  .cta-inner { flex-direction: column; align-items: flex-start; }
  .cta-final h2 { font-size: 24px; }
  .footer-inner { grid-template-columns: 1fr 1fr; }
  .footer-inner > div:first-child { grid-column: 1 / -1; }
  .float-tg { display: block; position: fixed; left: 16px; right: 16px; bottom: 16px; z-index: 40; background: var(--accent); color: #fff; text-align: center; font-weight: 600; padding: 14px; border-radius: 12px; box-shadow: 0 10px 30px rgba(31, 111, 235, .35); }
  .site-footer { padding-bottom: 96px; }
  .toast { bottom: 88px; }
  .article-hero h1 { font-size: 30px; }
  .article h2 { font-size: 23px; }
}

@media (max-width: 520px) {
  .own-grid { grid-template-columns: 1fr; }
  .trust-grid { grid-template-columns: repeat(2, 1fr); }
  .trust-grid > div { border-right: 1px solid var(--border) !important; border-bottom: 1px solid var(--border) !important; }
  .trust-grid > div:nth-child(2n) { border-right: 0 !important; }
  .trust-grid > div:last-child { grid-column: 1 / -1; border-bottom: 0 !important; border-right: 0 !important; }
  .hero-actions .btn { width: 100%; }
}