:root {
  color-scheme: light;
  --brand: #1975da;
  --brand-strong: #0e61bd;
  --brand-soft: #ecf2fe;
  --fact: #f7f9fc;
  --page: #ffffff;
  --ink: #172128;
  --body: #46545d;
  --muted: #71808a;
  --line: #dce5ed;
  --success: #15803d;
  --content-width: 1200px;
  font-family: "Microsoft YaHei", "PingFang SC", "Noto Sans CJK SC", sans-serif;
  font-synthesis: none;
  text-rendering: optimizeLegibility;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; background: var(--page); color: var(--ink); }
a { color: inherit; text-decoration: none; }
button, a { -webkit-tap-highlight-color: transparent; }
a:focus-visible, button:focus-visible { outline: 3px solid rgba(25, 117, 218, .3); outline-offset: 4px; }
.skip-link { position: fixed; top: 12px; left: 12px; z-index: 20; padding: 10px 14px; background: var(--ink); color: white; transform: translateY(-150%); }
.skip-link:focus { transform: translateY(0); }

.site-header, .document-header { width: min(calc(100% - 48px), var(--content-width)); min-height: 76px; margin: 0 auto; display: flex; align-items: center; justify-content: space-between; border-bottom: 1px solid var(--line); }
.brand { display: inline-flex; align-items: center; gap: 11px; font-weight: 700; letter-spacing: .01em; }
.brand img { flex: none; }
.brand-divider { width: 1px; height: 22px; background: var(--line); }
.brand-product { color: var(--body); font-weight: 600; }
.site-nav { display: flex; align-items: center; gap: 30px; color: var(--body); font-size: 14px; }
.site-nav a:hover, .back-link:hover, .text-action:hover { color: var(--brand); }
.site-nav .nav-login { min-height: 42px; padding: 11px 18px; border: 1px solid var(--brand); border-radius: 12px; color: var(--brand); font-weight: 700; }

.hero { width: min(calc(100% - 48px), var(--content-width)); margin: 34px auto 0; display: grid; grid-template-columns: minmax(0, 1.35fr) minmax(340px, .65fr); min-height: 590px; border: 1px solid var(--line); border-radius: 28px; overflow: hidden; }
.hero-copy { padding: 72px 70px 58px; background: var(--brand-soft); }
.eyebrow { margin: 0 0 14px; color: var(--brand); font-size: 14px; font-weight: 800; letter-spacing: .12em; }
h1, h2, h3, p { overflow-wrap: anywhere; }
.hero h1 { max-width: 720px; margin: 0; font-size: clamp(40px, 3.6vw, 52px); line-height: 1.18; letter-spacing: -.045em; }
.hero-summary { max-width: 670px; margin: 26px 0 0; color: var(--body); font-size: 18px; line-height: 1.85; }
.release-status { max-width: 670px; margin: 22px 0 0; padding-left: 14px; display: flex; gap: 12px; border-left: 3px solid var(--brand); color: var(--body); font-size: 14px; line-height: 1.7; }
.release-status strong { flex: none; color: var(--ink); }
.hero-actions { display: flex; align-items: center; gap: 26px; margin-top: 34px; }
.primary-action { display: inline-flex; align-items: center; justify-content: center; min-height: 50px; padding: 0 24px; border-radius: 14px; background: var(--brand); color: white; font-weight: 800; }
.primary-action:hover { background: var(--brand-strong); }
.text-action { color: var(--brand); font-weight: 700; }
.home-connect-ai { margin: 24px 0 0; color: var(--brand); font-size: 14px; line-height: 1.7; }
.home-connect-ai a { display: inline-block; padding: 6px 0; }
.hero-facts { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 0; margin: 56px 0 0; padding-top: 28px; border-top: 1px solid rgba(25, 117, 218, .18); }
.hero-facts div { padding-right: 18px; }
.hero-facts div + div { padding-left: 24px; border-left: 1px solid rgba(25, 117, 218, .18); }
.hero-facts dt { font-size: 24px; font-weight: 800; }
.hero-facts dd { margin: 7px 0 0; color: var(--muted); font-size: 13px; line-height: 1.5; }

.login-panel { display: flex; flex-direction: column; justify-content: center; padding: 44px 20px 32px; min-width: 0; background: white; }
.login-heading { display: flex; align-items: center; gap: 14px; }
.login-icon { width: 46px; height: 46px; display: grid; place-items: center; border-radius: 14px; background: var(--brand-soft); color: var(--brand); }
.login-icon svg { width: 28px; height: 28px; }
.panel-kicker { margin: 0 0 5px; color: var(--muted); font-size: 12px; }
.login-panel h2 { margin: 0; font-size: 24px; }
.login-qr { min-height: 240px; margin: 28px 0 0; display: grid; place-items: center; }
.login-qr iframe { display: block; width: 300px; max-width: 100%; height: 240px; border: 0; }
.login-status { margin: 16px 0; color: var(--body); font-size: 14px; line-height: 1.6; text-align: center; }
.login-retry { align-self: center; border: 0; padding: 10px; background: transparent; color: var(--brand); font: inherit; cursor: pointer; }
.login-panel [hidden] { display: none; }
.login-button { display: flex; align-items: center; justify-content: center; width: 100%; min-height: 50px; border: 0; border-radius: 8px; background: var(--brand); color: #fff; font: inherit; font-weight: 700; text-decoration: none; }
.login-note { margin: 16px 0 0; color: var(--muted); font-size: 12px; line-height: 1.65; }

.capability-section, .workflow-section, .trust-section { width: min(calc(100% - 48px), var(--content-width)); margin: 100px auto 0; }
.capability-section { display: grid; grid-template-columns: .72fr 1.28fr; gap: 78px; }
.section-intro { align-self: start; position: sticky; top: 28px; }
.section-intro h2, .section-heading-row h2, .trust-lead h2 { margin: 0; font-size: clamp(30px, 3vw, 42px); line-height: 1.25; letter-spacing: -.03em; }
.section-intro > p:last-child { margin: 22px 0 0; color: var(--body); font-size: 16px; line-height: 1.85; }
.capability-list { border-top: 1px solid var(--line); }
.capability-list article { display: grid; grid-template-columns: 52px 1fr; gap: 22px; padding: 30px 4px; border-bottom: 1px solid var(--line); }
.capability-number { color: var(--brand); font-size: 13px; font-weight: 800; letter-spacing: .08em; }
.capability-list h3 { margin: 0; font-size: 21px; }
.capability-list p { margin: 9px 0 0; color: var(--body); line-height: 1.8; }

.workflow-section { padding: 48px; border-radius: 28px; background: var(--fact); }
.section-heading-row { display: grid; grid-template-columns: 1.1fr .9fr; gap: 56px; align-items: end; }
.section-heading-row > p { margin: 0; color: var(--body); line-height: 1.8; }
.workflow-list { display: grid; grid-template-columns: repeat(4, 1fr); gap: 0; margin: 42px 0 0; padding: 0; list-style: none; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.workflow-list li { min-height: 158px; padding: 25px 22px; display: flex; gap: 16px; }
.workflow-list li + li { border-left: 1px solid var(--line); }
.workflow-list li > span { width: 28px; height: 28px; display: grid; place-items: center; flex: none; border-radius: 50%; background: white; border: 1px solid #b8cae2; color: var(--brand); font-size: 12px; font-weight: 800; }
.workflow-list strong { font-size: 18px; }
.workflow-list p { margin: 10px 0 0; color: var(--body); font-size: 14px; line-height: 1.7; }

.trust-section { display: grid; grid-template-columns: .85fr 1.15fr; gap: 70px; padding-bottom: 100px; }
.trust-points { border-top: 1px solid var(--line); }
.trust-points div { display: grid; grid-template-columns: 130px 1fr; gap: 28px; padding: 24px 0; border-bottom: 1px solid var(--line); }
.trust-points strong { color: var(--success); }
.trust-points span { color: var(--body); line-height: 1.7; }

.site-footer { padding: 34px max(24px, calc((100vw - var(--content-width)) / 2)); display: grid; grid-template-columns: 1fr auto; gap: 16px 28px; align-items: center; border-top: 1px solid var(--line); background: var(--fact); color: var(--body); }
.site-footer > div { display: flex; gap: 14px; align-items: baseline; }
.site-footer > div span { color: var(--muted); font-size: 13px; }
.site-footer nav { display: flex; gap: 24px; font-size: 14px; }
.site-footer nav a:hover { color: var(--brand); }
.legal-pending { grid-column: 1 / -1; margin: 0; color: var(--muted); font-size: 12px; }

.document-page { background: var(--fact); }
.document-header { background: white; }
.back-link { color: var(--brand); font-size: 14px; font-weight: 700; }
.document-shell { width: min(calc(100% - 48px), 850px); margin: 54px auto 90px; padding: 54px 62px; border: 1px solid var(--line); border-radius: 28px; background: white; }
.document-shell h1 { margin: 0; font-size: 42px; }
.document-lead { margin: 20px 0 36px; color: var(--body); font-size: 16px; line-height: 1.85; }
.document-shell section { padding: 24px 0; border-top: 1px solid var(--line); }
.document-shell h2 { margin: 0; font-size: 20px; }
.document-shell section p { margin: 12px 0 0; color: var(--body); line-height: 1.9; }

.connect-shell { width: min(calc(100% - 48px), 880px); margin: 58px auto 88px; }
.connect-intro h1 { margin: 0; font-size: clamp(30px, 4vw, 44px); line-height: 1.3; letter-spacing: -.03em; }
.connect-lead { margin: 20px 0 0; color: var(--body); font-size: 18px; line-height: 1.85; }
.connect-support { margin: 0 0 28px; color: var(--body); font-size: 14px; line-height: 1.85; }
.connect-entry h2 { margin: 0; font-size: 22px; line-height: 1.5; }
.connect-ai-page [hidden] { display: none; }
.connect-entry { margin: 32px 0 30px; padding: 28px; background: var(--brand-soft); border-radius: 6px; }
.connect-entry label { display: block; margin-bottom: 12px; color: var(--body); font-size: 14px; }
.connect-entry textarea { display: block; width: 100%; min-height: 112px; resize: vertical; padding: 14px 16px; border: 1px solid #b9c9d7; border-radius: 4px; background: white; color: var(--ink); font: inherit; font-size: 16px; line-height: 1.7; overflow-wrap: anywhere; }
.connect-entry .primary-action { min-height: 48px; margin-top: 20px; border: 1px solid var(--brand); font: inherit; font-weight: 600; cursor: pointer; }
.connect-entry .primary-action:disabled { background: #e0e7ed; border-color: #e0e7ed; color: var(--body); cursor: default; }
.connect-entry [role=status] { margin: 14px 0 0; color: var(--body); font-size: 14px; line-height: 1.8; }
.connect-retry { min-height: 44px; padding: 8px 0; border: 0; background: transparent; font: inherit; color: var(--brand-strong); cursor: pointer; }
.connect-ai-page textarea:focus-visible, .connect-ai-page button:focus-visible, .connect-ai-page summary:focus-visible, .connect-resources a:focus-visible { outline: 3px solid rgba(25,117,218,.35); outline-offset: 4px; }
.connect-developer { border-top: 1px solid var(--line); }
.connect-developer>summary { min-height: 48px; padding: 16px 0; color: var(--brand-strong); cursor: pointer; font-size: 14px; line-height: 1.7; }
.connect-developer-content { padding: 0 0 20px; font-size: 14px; line-height: 1.85; color: var(--body); }
.connect-developer-content p { margin: 0 0 14px; }
.connect-resources { display: flex; flex-wrap: wrap; gap: 4px 24px; }
.connect-resources a { display: inline-flex; min-height: 44px; align-items: center; color: var(--brand-strong); }
.connect-release { margin: 14px 0 0; font-size: 13px; line-height: 1.8; }
.connect-release>div { display: grid; grid-template-columns: 78px minmax(0,1fr); gap: 12px; margin-top: 8px; }
.connect-release dt { color: var(--body); }.connect-release dd { margin: 0; overflow-wrap: anywhere; }
@media (max-width: 620px) {
  .connect-shell { width: calc(100% - 32px); margin: 32px auto 48px; }
  .connect-lead { font-size: 16px; }
  .connect-entry { margin: 24px 0; padding: 20px 18px; }
  .connect-entry textarea { min-height: 164px; padding: 12px; }
  .connect-entry .primary-action { width: 100%; padding: 12px 14px; text-align: center; }
  .connect-ai-page .site-footer nav { flex-wrap: wrap; gap: 14px 20px; }
}

@media (max-width: 920px) {
  .site-header { min-height: auto; padding: 18px 0; align-items: flex-start; }
  .brand-product, .brand-divider { display: none; }
  .site-nav { gap: 14px; flex-wrap: wrap; justify-content: flex-end; }
  .site-nav a:not(.nav-login) { display: none; }
  .hero { grid-template-columns: 1fr; }
  .hero-copy { padding: 54px 42px; }
  .login-panel { padding: 42px; }
  .capability-section, .trust-section { grid-template-columns: 1fr; gap: 38px; }
  .section-intro { position: static; }
  .section-heading-row { grid-template-columns: 1fr; gap: 24px; }
  .workflow-list { grid-template-columns: repeat(2, 1fr); }
  .workflow-list li:nth-child(3) { border-left: 0; border-top: 1px solid var(--line); }
  .workflow-list li:nth-child(4) { border-top: 1px solid var(--line); }
}

@media (max-width: 620px) {
  .site-header, .document-header, .hero, .capability-section, .workflow-section, .trust-section { width: min(calc(100% - 28px), var(--content-width)); }
  .site-header { min-height: 68px; align-items: center; }
  .site-nav { gap: 0; }
  .site-nav .nav-login { min-height: 40px; padding: 10px 13px; }
  .hero { margin-top: 18px; border-radius: 22px; }
  .hero-copy { padding: 42px 24px 34px; }
  .hero h1 { font-size: 36px; }
  .hero-summary { font-size: 16px; }
  .release-status { display: block; }
  .release-status strong { display: block; margin-bottom: 3px; }
  .hero-actions { align-items: flex-start; flex-direction: column; gap: 18px; }
  .hero-facts { margin-top: 38px; }
  .hero-facts div { padding-right: 8px; }
  .hero-facts div + div { padding-left: 12px; }
  .hero-facts dt { font-size: 19px; }
  .login-panel { padding: 32px 24px; }
  .capability-section, .workflow-section, .trust-section { margin-top: 72px; }
  .capability-list article { grid-template-columns: 38px 1fr; gap: 12px; }
  .workflow-section { padding: 34px 20px; border-radius: 22px; }
  .workflow-list { grid-template-columns: 1fr; }
  .workflow-list li + li { border-left: 0; border-top: 1px solid var(--line); }
  .workflow-list li { min-height: auto; padding: 22px 4px; }
  .trust-section { padding-bottom: 72px; }
  .trust-points div { grid-template-columns: 1fr; gap: 7px; }
  .site-footer { grid-template-columns: 1fr; }
  .site-footer nav { grid-row: 2; }
  .legal-pending { grid-column: auto; }
  .document-shell { width: min(calc(100% - 28px), 850px); margin: 24px auto 64px; padding: 34px 24px; border-radius: 22px; }
  .document-shell h1 { font-size: 34px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}