:root {
  --site-primary: #667eea;
  --site-primary-dark: #5568d3;
  --site-secondary: #764ba2;
  --site-text: #1f2937;
  --site-muted: #6b7280;
  --site-border: #e5e7eb;
  --site-bg: #f8f7fc;
  --site-white: #ffffff;
  --site-focus: #4c1d95;
  --site-radius: 12px;
  --site-shadow: 0 8px 24px rgba(31, 41, 55, 0.08);
  --site-font: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans CJK SC", "Noto Sans CJK TC", "Microsoft YaHei", "PingFang SC", "PingFang TC", sans-serif;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

html,
body,
body.site-page {
  overflow: visible;
  height: auto;
}

.site-page {
  margin: 0;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background: var(--site-bg);
  color: var(--site-text);
  font-family: var(--site-font);
  line-height: 1.7;
}

.site-page a:focus-visible,
.site-page button:focus-visible,
.site-header select:focus-visible {
  outline: 3px solid var(--site-focus);
  outline-offset: 2px;
}

.app-header,
.site-header,
.site-banner,
.site-header-bar {
  position: static !important;
  top: auto !important;
}

.site-header {
  background: #fff;
}

.site-banner {
  display: block;
  background: #fff;
  line-height: 0;
  padding: 0.25rem 0 0;
}

.site-banner img {
  display: block;
  width: 100%;
  max-width: 932px;
  height: auto;
  max-height: 239px;
  aspect-ratio: 932 / 239;
  margin: 0 auto;
  object-fit: fill;
}

.site-header-bar {
  z-index: 20;
  background: #fff;
  border-top: 1px solid #f0d5d7;
  border-bottom: 1px solid var(--site-border);
}

.site-header-inner {
  max-width: 1180px;
  margin: 0 auto;
  padding: 0.35rem 1.25rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.site-nav {
  flex: 1;
}

.site-nav-list,
.site-nav-sub,
.site-breadcrumb-list,
.site-footer ul,
.site-related ul {
  list-style: none;
  margin: 0;
  padding: 0;
}

.site-nav-list {
  display: flex;
  align-items: center;
  gap: 0.15rem;
  flex-wrap: nowrap;
}

.site-nav-item {
  position: relative;
  flex-shrink: 0;
}

.site-nav-link,
.site-nav-toggle-sub {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  border: 0;
  background: transparent;
  color: var(--site-text);
  text-decoration: none;
  font: inherit;
  font-size: 0.9rem;
  font-weight: 600;
  padding: 0.4rem 0.55rem;
  border-radius: 8px;
  cursor: pointer;
  white-space: nowrap;
  word-break: keep-all;
  overflow-wrap: normal;
}

.site-header .site-nav-link,
.site-header .site-nav-toggle-sub {
  white-space: nowrap;
  word-break: keep-all;
  overflow-wrap: normal;
}

.site-nav-link:hover,
.site-nav-sublink:hover,
.site-nav-link.is-current,
.site-nav-sublink.is-current {
  color: var(--site-primary-dark);
  background: #eef1fd;
}

.site-nav-parent {
  display: flex;
  align-items: center;
}

.site-nav-caret {
  width: 0.45rem;
  height: 0.45rem;
  border-right: 2px solid currentColor;
  border-bottom: 2px solid currentColor;
  transform: rotate(45deg) translateY(-1px);
}

.site-nav-sub {
  position: absolute;
  top: 100%;
  left: 0;
  min-width: 17rem;
  background: var(--site-white);
  border: 1px solid var(--site-border);
  border-radius: 10px;
  box-shadow: var(--site-shadow);
  padding: 0.4rem;
  z-index: 5;
}

.site-nav-sublink {
  display: block;
  padding: 0.65rem 0.75rem;
  color: var(--site-text);
  text-decoration: none;
  border-radius: 8px;
  font-size: 0.92rem;
}

.site-header-tools {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-left: auto;
  flex-shrink: 0;
}

.site-header-cta,
.site-cta-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: #fff;
  text-decoration: none;
  font-weight: 600;
  border-radius: 999px;
  padding: 0.55rem 0.95rem;
  font-size: 0.9rem;
}

.site-header-cta:hover,
.site-cta-button:hover {
  filter: brightness(1.05);
}

.site-nav-hamburger {
  display: none;
  margin-right: auto;
  width: 36px;
  height: 36px;
  border: 1px solid var(--site-border);
  border-radius: 8px;
  background: #fff;
  padding: 10px 9px;
  flex-direction: column;
  justify-content: space-between;
  cursor: pointer;
}

.site-nav-hamburger-bar {
  display: block;
  height: 2px;
  background: var(--site-text);
  border-radius: 2px;
}

.site-header .language-selector-wrapper {
  position: static;
  transform: none;
}

.site-header .language-selector {
  max-width: 11rem;
}

.home-identity {
  text-align: center;
  padding: 1.25rem 1rem 0;
}

.home-identity .app-title {
  font-size: 1.75rem;
  font-weight: 700;
  margin: 0 0 0.25rem;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.home-identity .app-subtitle {
  margin: 0 auto;
  max-width: 40rem;
  color: #f8fafc;
  text-shadow: 0 1px 2px rgba(31, 41, 55, 0.25);
  line-height: 1.5;
}

.site-main {
  flex: 1;
  width: min(860px, calc(100% - 2rem));
  margin: 0 auto;
  padding: 2rem 0 4rem;
}

.site-article {
  background: var(--site-white);
  border: 1px solid var(--site-border);
  border-radius: 20px;
  box-shadow: var(--site-shadow);
  padding: 2rem 2.1rem 2.4rem;
}

.site-breadcrumbs {
  margin-bottom: 1rem;
  font-size: 0.9rem;
}

.site-breadcrumb-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem 0.5rem;
  color: var(--site-muted);
}

.site-breadcrumb-item:not(:last-child)::after {
  content: ">";
  margin-left: 0.5rem;
  color: #9ca3af;
}

.site-breadcrumb-item a {
  color: var(--site-primary-dark);
}

.site-kicker {
  text-transform: uppercase;
  letter-spacing: 0.06em;
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--site-secondary);
  margin: 0 0 0.35rem;
}

.site-article h1 {
  margin: 0 0 0.4rem;
  line-height: 1.25;
  font-size: clamp(1.7rem, 3vw, 2.2rem);
}

.site-byline {
  color: var(--site-muted);
  margin: 0 0 1.4rem;
  font-size: 0.95rem;
}

.site-article-body h2 {
  margin: 2rem 0 0.7rem;
  font-size: 1.35rem;
}

.site-article-body h3 {
  margin: 1.4rem 0 0.55rem;
  font-size: 1.12rem;
}

.site-article-body p,
.site-article-body li {
  color: #374151;
}

.site-article-body ul,
.site-article-body ol {
  padding-left: 1.2rem;
}

.site-article-body a {
  color: var(--site-primary-dark);
}

.example-chars,
.site-article-body td:nth-child(n+2) {
  font-size: 1.15rem;
}

.table-wrap {
  overflow-x: auto;
  margin: 1.2rem 0;
}

.site-article-body table {
  width: 100%;
  border-collapse: collapse;
}

.site-article-body th,
.site-article-body td {
  border: 1px solid var(--site-border);
  padding: 0.65rem 0.75rem;
  text-align: left;
}

.site-article-body th {
  background: #f3f4f6;
}

.site-cta {
  margin: 1.8rem 0;
  padding: 1.1rem 1.2rem;
  border: 1px solid #ddd6fe;
  background: #f5f3ff;
  border-radius: var(--site-radius);
}

.site-cta p {
  margin: 0 0 0.7rem;
  font-weight: 600;
}

.site-card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1rem;
  margin-top: 1.75rem;
}

.site-card {
  display: block;
  text-decoration: none;
  color: inherit;
  background: #fafafe;
  border: 1px solid var(--site-border);
  border-radius: 14px;
  padding: 1rem 1.05rem;
}

.site-card h2 {
  margin: 0 0 0.4rem;
  font-size: 1.05rem;
  color: var(--site-primary-dark);
}

.site-card p {
  margin: 0;
  color: var(--site-muted);
  font-size: 0.92rem;
}

.site-related {
  margin-top: 2.2rem;
  padding-top: 1.2rem;
  border-top: 1px solid var(--site-border);
}

.site-related a {
  color: var(--site-primary-dark);
}

.ad-slot[hidden],
.ad-slot[data-ad-enabled="false"] {
  display: none !important;
}

.site-footer {
  background: #111827;
  color: #e5e7eb;
  padding: 2.4rem 1.25rem 1.4rem;
}

.site-footer a {
  color: #ddd6fe;
  text-decoration: none;
}

.site-footer a:hover {
  text-decoration: underline;
}

.site-footer-inner {
  max-width: 1180px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1fr;
  gap: 1.5rem;
}

.site-footer-brand {
  font-weight: 700;
  margin: 0 0 0.4rem;
}

.site-footer-copy,
.site-footer-legal {
  color: #9ca3af;
}

.site-footer h2 {
  font-size: 0.95rem;
  margin: 0 0 0.6rem;
}

.site-footer li + li {
  margin-top: 0.35rem;
}

.site-footer-legal {
  max-width: 1180px;
  margin: 1.6rem auto 0;
  text-align: center;
  font-size: 0.88rem;
}

@media (max-width: 960px) {
  .site-nav-hamburger {
    display: flex;
  }

  .site-header-inner {
    flex-wrap: wrap;
  }

  .site-nav {
    display: none;
    flex-basis: 100%;
    order: 5;
  }

  .site-header.is-nav-open .site-nav {
    display: block;
  }

  .site-nav-list,
  .site-nav-parent {
    flex-direction: column;
    align-items: stretch;
  }

  .site-nav-item,
  .site-nav-link,
  .site-nav-toggle-sub {
    width: 100%;
    justify-content: space-between;
  }

  .site-nav-sub {
    position: static;
    box-shadow: none;
    border: 0;
    padding: 0 0 0.4rem 0.8rem;
    min-width: 0;
  }

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

@media (max-width: 640px) {
  .site-article {
    padding: 1.3rem 1.1rem 1.8rem;
  }

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

  .site-header-cta {
    display: none;
  }
}