:root {
  --bg: #f4f6fb;
  --bg-alt: #eef2ff;
  --surface: #ffffff;
  --text: #0f172a;
  --muted: #64748b;
  --primary: #1a56db;
  --primary-dark: #1347b8;
  --border: #e2e8f0;
  --shadow: 0 18px 50px rgba(15, 23, 42, 0.08);
  --radius: 16px;
  --max: 1120px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
}

a {
  color: inherit;
  text-decoration: none;
}

.container {
  width: min(100% - 32px, var(--max));
  margin: 0 auto;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: #121212;
  border-bottom: 1px solid #2a2a2a;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 56px;
  gap: 24px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 600;
  font-size: 17px;
  color: #f5f5f5;
  letter-spacing: 0.02em;
  flex-shrink: 0;
}

.brand:hover {
  color: #fff;
}

.brand-mark {
  display: block;
  width: 28px;
  height: 28px;
  border-radius: 4px;
  object-fit: contain;
  flex-shrink: 0;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 36px;
  height: 36px;
  padding: 0;
  border: 1px solid #3a3a3a;
  border-radius: 4px;
  background: transparent;
  cursor: pointer;
}

.nav-toggle span {
  display: block;
  width: 18px;
  height: 2px;
  margin: 0 auto;
  background: #d4d4d4;
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex: 1;
  gap: 32px;
  min-width: 0;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 28px;
}

.nav-links a {
  color: #a8a8a8;
  font-size: 14px;
  white-space: nowrap;
  padding: 4px 0;
  border-bottom: 2px solid transparent;
  transition: color 0.15s, border-color 0.15s;
}

.nav-links a:hover {
  color: #fff;
}

.nav-links a.is-active {
  color: #fff;
  border-bottom-color: #fff;
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-left: auto;
  flex-shrink: 0;
}

.nav-download {
  display: inline-block;
  padding: 7px 14px;
  border-radius: 4px;
  background: #5cb85c;
  color: #111 !important;
  font-size: 13px;
  font-weight: 600;
  white-space: nowrap;
}

.nav-download:hover {
  background: #6ec96e;
  color: #000 !important;
}

.nav-login {
  display: inline-block;
  padding: 6px 14px;
  border-radius: 4px;
  border: 1px solid #5a5a5a;
  background: transparent;
  color: #e8e8e8 !important;
  font-size: 13px;
  font-weight: 500;
  white-space: nowrap;
  transition: border-color 0.15s, color 0.15s, background 0.15s;
}

.nav-login:hover {
  border-color: #999;
  color: #fff !important;
  background: rgba(255, 255, 255, 0.06);
}

.site-header .lang-dropdown-trigger {
  border-color: #3a3a3a;
  background: #1a1a1a;
  color: #d4d4d4;
}

.site-header .lang-dropdown-trigger:hover {
  border-color: #555;
  color: #fff;
}

.site-header .lang-dropdown-chevron {
  color: #888;
}

.site-header .lang-dropdown-menu {
  border-color: #333;
  background: #1a1a1a;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.45);
}

.site-header .lang-dropdown-item {
  color: #ccc;
}

.site-header .lang-dropdown-item:hover {
  background: #252525;
}

.site-header .lang-dropdown-item.active {
  background: #2a2a2a;
  color: #fff;
}

.site-header .lang-dropdown-item.active .lang-dropdown-check {
  color: #5cb85c;
}

.page-anchor {
  height: 0;
}

.page-anchor,
#features,
#scenarios,
#process,
#why,
#download,
#faq {
  scroll-margin-top: 56px;
}

.lang-dropdown {
  position: relative;
  display: inline-block;
}

.lang-dropdown-trigger {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 6px 10px;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: #fff;
  color: var(--text);
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  line-height: 1.2;
}

.lang-dropdown-trigger:hover {
  border-color: #c7d2fe;
  color: var(--primary);
}

.lang-dropdown-chevron {
  font-size: 11px;
  color: var(--muted);
  line-height: 1;
}

.lang-dropdown-menu {
  position: absolute;
  top: calc(100% + 6px);
  right: 0;
  z-index: 50;
  min-width: 168px;
  padding: 6px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: #fff;
  box-shadow: 0 10px 30px rgba(15, 23, 42, 0.12);
}

.lang-dropdown-item {
  display: flex;
  align-items: center;
  gap: 8px;
  width: 100%;
  padding: 8px 10px;
  border: none;
  border-radius: 8px;
  background: transparent;
  color: var(--text);
  font-size: 13px;
  text-align: left;
  cursor: pointer;
}

.lang-dropdown-item:hover {
  background: #f8fafc;
}

.lang-dropdown-item.active {
  background: #eef2ff;
  color: #4f46e5;
}

.lang-dropdown-check {
  width: 14px;
  flex-shrink: 0;
  font-size: 12px;
  font-weight: 700;
  color: transparent;
}

.lang-dropdown-item.active .lang-dropdown-check {
  color: #4f46e5;
}

.hero {
  padding: 56px 0 48px;
  background: #141414;
  color: #f0f0f0;
  border-bottom: 1px solid #2a2a2a;
}

.hero-inner {
  max-width: 880px;
  margin: 0 auto;
  text-align: center;
}

.hero-badge {
  display: inline-block;
  margin: 0 0 24px;
  padding: 6px 14px;
  border: 1px solid #444;
  border-radius: 4px;
  background: #1a1a1a;
  color: #c8c8c8;
  font-size: 13px;
  line-height: 1.4;
}

.hero h1 {
  margin: 0 0 20px;
  font-size: clamp(30px, 5vw, 44px);
  line-height: 1.3;
  font-weight: 600;
  color: #fff;
  letter-spacing: 0.02em;
}

.hero-accent {
  color: #5cb85c;
}

.hero-subline {
  margin: 0 0 10px;
  color: #d6d6d6;
  font-size: 15px;
  line-height: 1.6;
}

.hero-tagline {
  margin: 0 0 28px;
  color: #b3b3b3;
  font-size: 14px;
  line-height: 1.5;
}

.hero-cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 42px;
  padding: 0 28px;
  margin-bottom: 36px;
  border: 1px solid #666;
  border-radius: 4px;
  color: #eee;
  font-size: 14px;
  font-weight: 500;
  background: transparent;
  transition: border-color 0.15s, color 0.15s, background 0.15s;
}

.hero-cta:hover {
  border-color: #999;
  color: #fff;
  background: rgba(255, 255, 255, 0.05);
}

.hero-pills {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
  margin: 0 0 28px;
  padding: 0;
  list-style: none;
}

.hero-pills li {
  padding: 8px 16px;
  border: 1px solid #333;
  border-radius: 4px;
  background: #1a1a1a;
  color: #ccc;
  font-size: 13px;
  line-height: 1.4;
  white-space: nowrap;
}

.hero-meta {
  margin: 0;
  color: #a8a8a8;
  font-size: 13px;
}

.hero-meta strong {
  color: #d8d8d8;
  font-weight: 600;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 40px;
  align-items: center;
}

.eyebrow {
  display: inline-block;
  margin: 0 0 12px;
  padding: 6px 12px;
  border-radius: 999px;
  background: var(--bg-alt);
  color: var(--primary);
  font-size: 13px;
  font-weight: 600;
}

.lead {
  margin: 0 0 28px;
  color: var(--muted);
  font-size: 17px;
  max-width: 560px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 20px;
  border-radius: 12px;
  font-weight: 600;
  transition: transform 0.15s ease, background 0.15s ease;
}

.btn:hover {
  transform: translateY(-1px);
}

.btn-primary {
  background: var(--primary);
  color: #fff;
  box-shadow: 0 10px 24px rgba(26, 86, 219, 0.25);
}

.btn-primary:hover {
  background: var(--primary-dark);
}

.btn-ghost {
  border: 1px solid var(--border);
  background: #fff;
}

.btn-block {
  width: 100%;
}

.hero-panel {
  display: grid;
  gap: 16px;
}

.panel-card {
  padding: 22px;
  border-radius: var(--radius);
  background: var(--surface);
  box-shadow: var(--shadow);
  border: 1px solid rgba(255, 255, 255, 0.7);
}

.panel-card.secondary {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

.panel-title {
  font-weight: 700;
  margin-bottom: 14px;
}

.panel-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.panel-list li {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 14px;
}

.dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
}

.dot.ok {
  background: #22c55e;
}

.dot.idle {
  background: #cbd5e1;
}

.panel-stat span {
  display: block;
  font-size: 12px;
  color: var(--muted);
}

.panel-stat em {
  font-style: normal;
  font-weight: 700;
}

.section {
  padding: 72px 0;
}

.section-alt {
  background: var(--bg-alt);
}

.section-title {
  margin: 0 0 8px;
  font-size: 30px;
}

.section-desc {
  margin: 0 0 32px;
  color: var(--muted);
}

.features-intro {
  text-align: center;
  margin-bottom: 32px;
}

.features-intro .section-desc {
  max-width: 560px;
  margin-left: auto;
  margin-right: auto;
  margin-bottom: 0;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(6, minmax(0, 1fr));
  gap: 18px;
}

.feature-card {
  grid-column: span 2;
  padding: 22px;
  border-radius: var(--radius);
  background: var(--surface);
  border: 1px solid var(--border);
}

.feature-card:nth-child(4) {
  grid-column: 2 / span 2;
}

.feature-card:nth-child(5) {
  grid-column: 4 / span 2;
}

.feature-card h3 {
  margin: 0 0 10px;
  font-size: 18px;
}

.feature-card p {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
}

.scenario-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.scenario-card {
  padding: 22px;
  border-radius: var(--radius);
  background: var(--surface);
  border: 1px solid var(--border);
}

.scenario-card h3 {
  margin: 0 0 10px;
  font-size: 18px;
}

.scenario-card p {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
}

.process-steps {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: 18px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.process-step {
  padding: 22px;
  border-radius: var(--radius);
  background: var(--surface);
  border: 1px solid var(--border);
}

.process-num {
  display: block;
  margin-bottom: 10px;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--primary);
}

.process-step h3 {
  margin: 0 0 8px;
  font-size: 17px;
}

.process-step p {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.6;
}

.download-platforms {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 20px;
  max-width: 1080px;
  margin: 0 auto;
}

.platform-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 32px 20px 28px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  text-align: center;
}

.platform-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 64px;
  height: 64px;
  margin-bottom: 16px;
}

.platform-icon svg {
  display: block;
  width: 48px;
  height: 48px;
  overflow: visible;
}

.platform-name {
  margin: 0 0 8px;
  font-size: 18px;
  font-weight: 700;
  color: var(--text);
}

.platform-note {
  margin: 0 0 24px;
  font-size: 13px;
  color: var(--muted);
  line-height: 1.5;
  min-height: 20px;
}

.platform-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  max-width: 180px;
  min-height: 44px;
  margin-top: auto;
  padding: 0 20px;
  border: none;
  border-radius: 12px;
  font-size: 14px;
  font-weight: 600;
  line-height: 1.2;
  text-decoration: none;
  cursor: pointer;
  transition: transform 0.15s ease, background 0.15s ease, box-shadow 0.15s ease;
}

.platform-btn-primary {
  color: #fff;
  background: var(--primary);
  box-shadow: 0 10px 24px rgba(26, 86, 219, 0.25);
}

.platform-btn-primary:hover {
  background: var(--primary-dark);
  transform: translateY(-1px);
}

.platform-btn-disabled {
  color: var(--muted);
  background: var(--bg-alt);
  border: 1px solid var(--border);
  cursor: default;
  user-select: none;
  box-shadow: none;
}

.faq-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.faq-item {
  padding: 20px 22px;
  border-radius: var(--radius);
  background: var(--surface);
  border: 1px solid var(--border);
}

.faq-item h3 {
  margin: 0 0 8px;
  font-size: 16px;
  line-height: 1.4;
}

.faq-item p {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.65;
}

.link-muted {
  font-size: 14px;
  color: var(--primary);
}

.narrow {
  max-width: 880px;
}

.site-footer {
  margin-top: 0;
  padding: 48px 0 0;
  background: #121212;
  color: rgba(255, 255, 255, 0.65);
  font-size: 14px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.35fr repeat(3, 1fr);
  gap: 32px 24px;
  padding-bottom: 36px;
}

.footer-brand-link {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: #fff;
  text-decoration: none;
  font-weight: 700;
  font-size: 18px;
}

.footer-brand-link img {
  border-radius: 6px;
}

.footer-tagline {
  margin: 14px 0 0;
  max-width: 280px;
  font-size: 14px;
  line-height: 1.65;
  color: rgba(255, 255, 255, 0.55);
}

.footer-col h4 {
  margin: 0 0 14px;
  font-size: 14px;
  font-weight: 600;
  color: #fff;
}

.footer-col ul {
  margin: 0;
  padding: 0;
  list-style: none;
}

.footer-col li + li {
  margin-top: 10px;
}

.footer-col a {
  color: rgba(255, 255, 255, 0.65);
  text-decoration: none;
  transition: color 0.15s ease;
}

.footer-col a:hover {
  color: #fff;
}

#footer-contact {
  scroll-margin-top: 72px;
}

.footer-contact {
  width: 100%;
  margin: 0 0 20px;
  padding-bottom: 4px;
  text-align: center;
  font-size: 0;
  line-height: 26px;
  font-family: "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  color: rgba(255, 255, 255, 0.88);
}

.footer-contact-label,
.footer-contact-link,
.footer-contact-sep {
  display: inline-block;
  vertical-align: middle;
  margin: 0;
  padding: 0;
  font-size: 16px;
  line-height: 26px;
  font-family: inherit;
}

.footer-contact-label:empty {
  display: none;
}

.footer-contact-label:not(:empty) {
  margin-right: 8px;
  font-weight: 500;
  color: rgba(255, 255, 255, 0.88);
}

.footer-contact-sep {
  color: rgba(255, 255, 255, 0.45);
  user-select: none;
  margin: 0 12px;
}

.footer-contact-link {
  color: #fff;
  font-weight: 600;
  letter-spacing: 0.02em;
  text-decoration: none;
}

.footer-contact-link:hover {
  color: #fff;
  text-decoration: underline;
  text-underline-offset: 3px;
}

.footer-bottom {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
  padding: 20px 0 28px;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-bottom-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px 24px;
  width: 100%;
}

.footer-copy,
.footer-note {
  margin: 0;
  font-size: 13px;
  line-height: 1.5;
  color: rgba(255, 255, 255, 0.45);
}

.footer-note {
  max-width: 520px;
  text-align: right;
}

@media (max-width: 960px) {
  .download-platforms {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .nav-toggle {
    display: flex;
    margin-left: auto;
  }

  .nav {
    display: none;
    position: absolute;
    top: 56px;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 12px 16px 16px;
    background: #121212;
    border-bottom: 1px solid #2a2a2a;
  }

  .nav.is-open {
    display: flex;
  }

  .nav-links {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
  }

  .nav-links a {
    padding: 12px 4px;
    border-bottom: 1px solid #222;
  }

  .nav-links a.is-active {
    border-bottom-color: #222;
    border-left: 2px solid #5cb85c;
    padding-left: 8px;
  }

  .nav-actions {
    flex-direction: column;
    align-items: stretch;
    margin-left: 0;
    margin-top: 12px;
    gap: 10px;
  }

  .nav-download {
    text-align: center;
  }

  .nav-login {
    text-align: center;
  }

  .header-inner {
    position: relative;
    flex-wrap: wrap;
  }
}

@media (max-width: 640px) {
  .footer-grid {
    grid-template-columns: 1fr;
  }

  .footer-bottom {
    align-items: center;
  }

  .footer-bottom-meta {
    flex-direction: column;
    align-items: center;
    text-align: center;
  }
}

@media (max-width: 900px) {
  .hero-pills li {
    white-space: normal;
  }

  .download-platforms,
  .feature-grid,
  .scenario-grid,
  .process-steps {
    grid-template-columns: 1fr;
  }

  .feature-card,
  .feature-card:nth-child(4),
  .feature-card:nth-child(5) {
    grid-column: auto;
  }

  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }

  .footer-brand {
    grid-column: 1 / -1;
  }

  .footer-tagline {
    max-width: none;
  }

  .footer-note {
    text-align: left;
  }
}

.help-page {
  padding: 48px 0 80px;
  background: #0f0f0f;
}

.help-header {
  margin-bottom: 32px;
}

.help-header h1 {
  margin: 0 0 12px;
  font-size: clamp(28px, 4vw, 36px);
  font-weight: 700;
  color: #f5f5f5;
  letter-spacing: 0.01em;
}

.help-desc {
  margin: 0;
  font-size: 16px;
  line-height: 1.7;
  color: #a8a8a8;
}

.help-layout {
  display: grid;
  grid-template-columns: minmax(260px, max-content) minmax(0, 1fr);
  gap: 28px;
  align-items: start;
}

.help-layout.is-empty {
  grid-template-columns: 1fr;
}

.help-layout.is-empty .help-sidebar {
  display: none;
}

.help-sidebar {
  position: sticky;
  top: 80px;
  width: max-content;
  min-width: 260px;
  padding: 20px 16px;
  border: 1px solid #2a2a2a;
  border-radius: 8px;
  background: #161616;
}

.help-sidebar-title {
  margin: 0 0 14px;
  padding: 0 8px 12px;
  border-bottom: 1px solid #2a2a2a;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: #888;
}

.help-nav {
  display: flex;
  flex-direction: column;
  gap: 4px;
  width: max-content;
  min-width: 100%;
}

.help-nav-item {
  display: block;
  width: 100%;
  padding: 10px 12px;
  border: none;
  border-radius: 6px;
  background: transparent;
  color: #b8b8b8;
  font-size: 14px;
  line-height: 1.5;
  text-align: left;
  white-space: nowrap;
  cursor: pointer;
  transition: background 0.15s, color 0.15s;
}

.help-nav-item:hover {
  background: rgba(255, 255, 255, 0.06);
  color: #f0f0f0;
}

.help-nav-item.is-active {
  background: rgba(26, 86, 219, 0.18);
  color: #fff;
  box-shadow: inset 3px 0 0 #1a56db;
}

.help-content {
  min-width: 0;
}

.help-article {
  padding: 32px 36px;
  border: 1px solid #2a2a2a;
  border-radius: 8px;
  background: #161616;
  min-height: 360px;
}

.help-content-title {
  margin: 0 0 20px;
  padding-bottom: 16px;
  border-bottom: 1px solid #2a2a2a;
  font-size: 24px;
  font-weight: 600;
  color: #f0f0f0;
}

.help-content-body,
.help-content-body p,
.help-content-body li {
  font-size: 15px;
  line-height: 1.75;
  color: #c8c8c8;
}

.help-content-body h2 {
  margin: 28px 0 12px;
  font-size: 20px;
  color: #f0f0f0;
}

.help-content-body h3 {
  margin: 22px 0 10px;
  font-size: 17px;
  color: #e8e8e8;
}

.help-content-body ul,
.help-content-body ol {
  margin: 0 0 16px;
  padding-left: 1.4em;
}

.help-content-body li + li {
  margin-top: 8px;
}

.help-content-body img,
.help-content-body video {
  display: block;
  max-width: 100%;
  height: auto;
  margin: 20px 0;
  border-radius: 6px;
}

.help-content-body a {
  color: #6ea8fe;
}

.help-content-body a:hover {
  color: #9ec5fe;
}

.help-placeholder {
  margin: 0;
  padding: 48px 16px;
  text-align: center;
  color: #888;
  font-size: 15px;
}

@media (max-width: 900px) {
  .help-layout {
    grid-template-columns: 1fr;
    gap: 20px;
  }

  .help-sidebar {
    position: static;
    width: 100%;
    max-width: none;
  }

  .help-nav {
    max-height: 220px;
    overflow-x: auto;
    overflow-y: auto;
  }

  .help-article {
    padding: 24px 20px;
  }
}