/* Fantula 帮助中心 v3 — 深色，与主站融合
   依据：博客帮助中心改版设计需求.md
*/

:root {
  color-scheme: dark;
  /* Background — 与主站 slate-900 对齐 */
  --bg:           #0F172A;
  --bg-card:      #1a2540;
  --bg-elev:      #243050;
  --bg-soft:      rgba(255,255,255,0.05);

  /* Borders */
  --border:       rgba(255,255,255,0.08);
  --border-hover: rgba(23,143,198,0.4);
  --divider:      rgba(255,255,255,0.06);

  /* Text */
  --text:         #F1F5F9;
  --text-2:       #cbd5e1;
  --text-3:       #94a3b8;
  --text-4:       #64748b;

  /* Brand — 与主站 blue-500 对齐 */
  --brand:        #178fc6;
  --brand-hover:  #1279aa;
  --brand-soft:   rgba(23,143,198,0.12);

  /* 强调橙 — 与主站 orange-500 对齐，用于CTA按钮 */
  --accent:       #F97316;
  --accent-hover: #ea6c0a;
  --accent-soft:  rgba(249,115,22,0.12);

  /* Product tag colors */
  --c-yt-bg:      rgba(239,68,68,0.15);
  --c-yt-fg:      #f87171;
  --c-sp-bg:      rgba(34,197,94,0.15);
  --c-sp-fg:      #4ade80;
  --c-ch-bg:      rgba(168,85,247,0.15);
  --c-ch-fg:      #c084fc;

  /* Type */
  --sans:         "Inter", "PingFang SC", "Microsoft YaHei", -apple-system, "Helvetica Neue", Arial, sans-serif;
  --mono:         "JetBrains Mono", "SF Mono", Menlo, Consolas, monospace;

  --container: 1200px;
  --sidebar:   240px;
}

@media (prefers-color-scheme: light) {
  :root { color-scheme: dark; }
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; background: var(--bg); }
body {
  font-family: var(--sans);
  color: var(--text);
  font-size: 15px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  min-height: 100vh;
}

/* Subtle starfield glow */
body::before {
  content: ""; position: fixed; inset: 0; z-index: -1; pointer-events: none;
  background:
    radial-gradient(ellipse 70% 50% at 50% -10%, rgba(59,130,246,0.10) 0%, transparent 60%),
    radial-gradient(ellipse 60% 40% at 90% 100%, rgba(168,85,247,0.06) 0%, transparent 60%);
}

a { color: inherit; text-decoration: none; }
button { font: inherit; cursor: pointer; }
img { max-width: 100%; display: block; }

.container { max-width: var(--container); margin: 0 auto; padding: 0 24px; }

/* ============ TOP NAV (matches main site) ============ */
.topnav {
  position: sticky; top: 0; z-index: 50;
  background: rgba(2,6,23,0.85);
  backdrop-filter: saturate(160%) blur(14px);
  -webkit-backdrop-filter: saturate(160%) blur(14px);
  border-bottom: 1px solid var(--border);
}
.topnav__inner {
  display: flex; align-items: center; justify-content: space-between;
  height: 64px;
}
.logo {
  display: flex; align-items: center; gap: 10px;
  font-weight: 700; font-size: 18px; color: var(--text);
  letter-spacing: -0.01em;
}
.logo__mark {
  width: 30px; height: 30px; border-radius: 8px;
  background: linear-gradient(135deg, var(--brand) 0%, #1e3a8a 100%);
  position: relative; flex-shrink: 0;
  box-shadow: 0 2px 8px rgba(59,130,246,0.3);
}
.logo__mark::after {
  content: ""; position: absolute; inset: 8px;
  background: #fff; border-radius: 50%;
  clip-path: polygon(35% 25%, 35% 75%, 75% 50%);
}

.topnav__links { display: flex; gap: 4px; align-items: center; }
.topnav__links a {
  padding: 8px 14px; border-radius: 8px;
  color: var(--text-3); font-size: 14px; font-weight: 500;
  transition: all .15s;
}
.topnav__links a:hover { background: var(--bg-soft); color: var(--text); }
.topnav__links a.is-active { color: var(--brand); background: var(--brand-soft); }

.topnav__right { display: flex; align-items: center; gap: 10px; }

.lang-dropdown { position: relative; }
.lang-dropdown__trigger {
  display: flex; align-items: center; gap: 6px;
  padding: 7px 12px; border-radius: 8px;
  background: var(--bg-soft); border: 1px solid var(--border);
  color: var(--text-2); font-size: 13px; font-weight: 500;
  transition: all .15s;
}
.lang-dropdown__trigger:hover { background: var(--bg-elev); border-color: rgba(255,255,255,0.15); }
.lang-dropdown__menu {
  position: absolute; top: calc(100% + 6px); right: 0;
  min-width: 140px;
  background: var(--bg-elev); border: 1px solid rgba(255,255,255,0.10);
  border-radius: 10px; padding: 6px;
  box-shadow: 0 12px 40px rgba(0,0,0,0.4);
  z-index: 60;
}
.lang-dropdown__item {
  display: flex; align-items: center; justify-content: space-between;
  padding: 8px 12px; border-radius: 6px;
  font-size: 13px; color: var(--text-2);
  cursor: pointer; transition: background .12s;
}
.lang-dropdown__item:hover { background: rgba(255,255,255,0.06); color: var(--text); }
.lang-dropdown__item.is-active { color: var(--brand); }
.lang-dropdown__check { color: var(--brand); }

.btn-login {
  padding: 8px 18px; border-radius: 8px;
  background: var(--brand); color: #fff;
  font-size: 13px; font-weight: 600; border: 0;
  transition: all .15s;
}
.btn-login:hover { background: var(--brand-hover); transform: translateY(-1px); box-shadow: 0 4px 14px rgba(59,130,246,0.3); }
.btn-login--ghost {
  background: transparent; color: var(--text-2);
  border: 1px solid var(--border);
}
.btn-login--ghost:hover { background: var(--bg-soft); color: var(--text); border-color: rgba(255,255,255,0.16); }

/* ============ BREADCRUMB ============ */
.breadcrumb {
  display: flex; gap: 8px; align-items: center;
  font-size: 13px; color: var(--text-4);
  padding: 20px 0;
}
.breadcrumb a:hover { color: var(--brand); }
.breadcrumb .sep { color: rgba(255,255,255,0.15); }
.breadcrumb .current { color: var(--text-2); }

/* ============ HELP HEADER ============ */
.help-header { padding: 24px 0 40px; }
.help-header h1 {
  font-size: 32px; font-weight: 700; letter-spacing: -0.02em;
  margin: 0 0 8px; color: var(--text);
}
.help-header__sub {
  font-size: 16px; color: var(--text-3); margin: 0 0 24px;
}
.search-box {
  position: relative; max-width: 560px;
}
.search-box input {
  width: 100%;
  padding: 14px 16px 14px 44px;
  background: var(--bg-soft); border: 1px solid var(--border);
  border-radius: 10px; color: var(--text); font-size: 14px;
  font-family: inherit; outline: none;
  transition: all .15s;
}
.search-box input::placeholder { color: var(--text-4); }
.search-box input:focus { border-color: var(--brand); background: rgba(59,130,246,0.06); box-shadow: 0 0 0 3px rgba(59,130,246,0.15); }
.search-box__icon {
  position: absolute; left: 14px; top: 50%; transform: translateY(-50%);
  width: 18px; height: 18px; color: var(--text-4); pointer-events: none;
}

/* ============ LAYOUT: sidebar + main ============ */
.layout {
  display: grid; grid-template-columns: var(--sidebar) 1fr;
  gap: 40px; padding-bottom: 80px;
}
.layout--article { grid-template-columns: 1fr 300px; gap: 48px; }

/* Sidebar */
.sidebar { font-size: 14px; }
.sidebar__section { margin-bottom: 32px; }
.sidebar__title {
  font-size: 12px; font-weight: 600; color: var(--text-4);
  letter-spacing: 0.08em; text-transform: uppercase;
  display: flex; align-items: center; gap: 8px;
  margin-bottom: 14px;
}
.sidebar__title .icon { width: 14px; height: 14px; }
.sidebar__list { display: flex; flex-direction: column; gap: 2px; }
.sidebar__item {
  display: flex; justify-content: space-between; align-items: center;
  padding: 8px 12px; border-radius: 7px;
  color: var(--text-3); font-size: 14px;
  cursor: pointer; transition: all .12s;
  border: 0; background: transparent; text-align: left;
}
.sidebar__item:hover { background: var(--bg-soft); color: var(--text); }
.sidebar__item.is-active { background: var(--brand-soft); color: var(--brand); font-weight: 500; }
.sidebar__item-count { font-size: 12px; color: var(--text-4); }
.sidebar__item.is-active .sidebar__item-count { color: var(--brand); opacity: 0.8; }

.sidebar__hot li {
  padding: 8px 12px; border-radius: 7px;
  font-size: 13px; color: var(--text-3); line-height: 1.5;
  cursor: pointer; transition: all .12s;
  display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden;
  list-style: none;
}
.sidebar__hot { padding: 0; margin: 0; }
.sidebar__hot li:hover { background: var(--bg-soft); color: var(--text); }

/* CTA cards in sidebar */
.cta-card {
  display: block;
  padding: 16px;
  background: linear-gradient(135deg, rgba(59,130,246,0.08) 0%, rgba(168,85,247,0.05) 100%);
  border: 1px solid var(--border);
  border-radius: 10px;
  margin-bottom: 10px;
  transition: all .2s;
  cursor: pointer;
}
.cta-card:hover { border-color: rgba(59,130,246,0.4); transform: translateY(-2px); box-shadow: 0 8px 20px rgba(0,0,0,0.2); }
.cta-card__tag {
  font-size: 11px; font-weight: 600;
  padding: 2px 8px; border-radius: 100px;
  display: inline-block; margin-bottom: 0;
}
.cta-card__head {
  display: flex; align-items: center; justify-content: space-between; margin-bottom: 8px;
}
.cta-card__badge {
  font-size: 10px; font-weight: 700; padding: 2px 6px; border-radius: 4px;
  background: rgba(251,191,36,0.15); color: #fbbf24; border: 1px solid rgba(251,191,36,0.3);
}
.cta-card__name {
  font-size: 14px; font-weight: 600; color: var(--text);
  margin: 0 0 4px;
}
.cta-card__stats {
  display: flex; align-items: center; gap: 8px;
  font-size: 11px; color: var(--text-3); margin: 4px 0 8px;
}
.cta-card__rating { color: #fbbf24; }
.cta-card__sales { color: var(--text-3); }
.cta-card__price {
  font-size: 12px; color: var(--text-3); margin: 0 0 10px;
}
.cta-card__price strong { color: var(--brand); font-size: 14px; }
.cta-card__btn {
  display: flex; align-items: center; justify-content: space-between;
  font-size: 12px; font-weight: 600; color: var(--brand);
}

/* ============ MAIN: article list ============ */
.article-list { display: flex; flex-direction: column; gap: 16px; }
.article-card {
  display: block;
  padding: 20px 24px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 8px;
  transition: all .2s ease;
  cursor: pointer;
}
.article-card:hover {
  border-color: var(--border-hover);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px -8px rgba(0,0,0,0.4);
}
.article-card__tag {
  display: inline-flex; align-items: center; gap: 5px;
  padding: 3px 10px; border-radius: 100px;
  font-size: 11px; font-weight: 600;
  margin-bottom: 12px;
}
.article-card__tag--yt { background: var(--c-yt-bg); color: var(--c-yt-fg); }
.article-card__tag--sp { background: var(--c-sp-bg); color: var(--c-sp-fg); }
.article-card__tag--ch { background: var(--c-ch-bg); color: var(--c-ch-fg); }
.article-card__title {
  font-size: 18px; font-weight: 600; line-height: 1.4;
  margin: 0 0 8px; color: var(--text);
  text-wrap: pretty;
  transition: color .15s;
}
.article-card:hover .article-card__title { color: var(--brand); }
.article-card__excerpt {
  font-size: 14px; color: var(--text-3); line-height: 1.6;
  margin: 0 0 12px;
  display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical;
  overflow: hidden;
}
.article-card__meta {
  font-size: 12px; color: var(--text-4);
  display: flex; gap: 8px; align-items: center;
}
.article-card__meta .dot { width: 3px; height: 3px; border-radius: 50%; background: currentColor; }

/* ============ ARTICLE PAGE ============ */
.article-page {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 40px 48px;
}
.article-page__tag {
  display: inline-flex; align-items: center; gap: 5px;
  padding: 4px 12px; border-radius: 100px;
  font-size: 12px; font-weight: 600;
  margin-bottom: 18px;
}
.article-page__title {
  font-size: 32px; font-weight: 700;
  letter-spacing: -0.02em; line-height: 1.25;
  margin: 0 0 16px; color: var(--text);
  text-wrap: balance;
}
.article-page__meta {
  font-size: 13px; color: var(--text-4);
  padding-bottom: 24px; border-bottom: 1px solid var(--divider);
  margin-bottom: 28px;
  display: flex; gap: 12px; align-items: center;
}

.article-body { font-size: 16px; line-height: 1.85; color: var(--text-2); }
.article-body p { margin: 0 0 22px; }
.article-body h2 {
  font-size: 22px; font-weight: 600;
  color: var(--text); margin: 40px 0 14px;
  line-height: 1.4; scroll-margin-top: 80px;
}
.article-body h3 {
  font-size: 18px; font-weight: 600;
  color: var(--text); margin: 28px 0 10px;
}
.article-body strong { color: var(--text); font-weight: 600; }
.article-body a { color: var(--brand); text-decoration: underline; text-decoration-thickness: 1px; text-underline-offset: 3px; }
.article-body a:hover { color: var(--brand-hover); }
.article-body code {
  font-family: var(--mono); font-size: 0.88em;
  background: var(--bg-soft); padding: 2px 7px; border-radius: 4px;
  border: 1px solid var(--border); color: #93c5fd;
}
.article-body ul, .article-body ol { padding-left: 24px; margin: 0 0 22px; }
.article-body li { margin-bottom: 8px; }
.article-body table {
  width: 100%; border-collapse: collapse;
  font-size: 14px; margin: 24px 0;
  border-radius: 8px; overflow: hidden;
  border: 1px solid var(--border);
}
.article-body th {
  text-align: left; padding: 12px 16px;
  background: var(--bg-soft); font-size: 12px;
  font-weight: 600; color: var(--text-3); letter-spacing: 0.04em;
}
.article-body td { padding: 12px 16px; border-top: 1px solid var(--divider); color: var(--text-2); }

.callout {
  background: var(--brand-soft);
  border-left: 3px solid var(--brand);
  padding: 16px 20px;
  border-radius: 8px;
  margin: 24px 0;
  font-size: 14px;
}
.callout strong { display: block; margin-bottom: 4px; color: var(--text); }
.callout p { margin: 0; color: var(--text-2); }

.article-nav {
  display: flex; justify-content: space-between; gap: 16px;
  margin-top: 48px; padding-top: 24px;
  border-top: 1px solid var(--divider);
}
.article-nav a {
  flex: 1; padding: 16px 20px;
  background: var(--bg-soft); border: 1px solid var(--border);
  border-radius: 8px; transition: all .15s;
}
.article-nav a:hover { border-color: var(--border-hover); background: var(--brand-soft); }
.article-nav__dir { font-size: 12px; color: var(--text-4); margin-bottom: 4px; }
.article-nav__t { font-size: 14px; color: var(--text); font-weight: 500; }
.article-nav a.next { text-align: right; }

/* ============ MOBILE ============ */
.cat-tabs { display: none; }
.mobile-cta-bar { display: none; }

@media (max-width: 900px) {
  .layout, .layout--article { grid-template-columns: 1fr; gap: 0; }
  .sidebar { display: none; }
  .article-page { padding: 28px 20px; border-radius: 8px; }
  .article-page__title { font-size: 24px; }
  .topnav__links { display: none; }
  .help-header h1 { font-size: 26px; }

  /* Mobile category tabs */
  .cat-tabs {
    display: flex; gap: 6px;
    overflow-x: auto; padding: 0 24px 16px;
    margin: 0 -24px 16px;
    -ms-overflow-style: none; scrollbar-width: none;
  }
  .cat-tabs::-webkit-scrollbar { display: none; }
  .cat-tabs button {
    flex-shrink: 0; padding: 8px 14px;
    background: var(--bg-soft); border: 1px solid var(--border);
    border-radius: 100px; color: var(--text-3);
    font-size: 13px; font-weight: 500; white-space: nowrap;
  }
  .cat-tabs button.is-active { background: var(--brand-soft); color: var(--brand); border-color: var(--brand); }

  /* Mobile fixed CTA bar on article page */
  .mobile-cta-bar {
    display: flex; align-items: center; justify-content: space-between;
    position: fixed; bottom: 0; left: 0; right: 0; z-index: 40;
    padding: 12px 20px;
    background: rgba(2,6,23,0.95);
    backdrop-filter: blur(14px);
    border-top: 1px solid var(--border);
    font-size: 13px;
  }
  .mobile-cta-bar__text { color: var(--text-2); }
  .mobile-cta-bar__text strong { color: var(--text); display: block; font-size: 14px; margin-bottom: 2px; }
  .mobile-cta-bar__text em { color: var(--brand); font-style: normal; font-weight: 700; }
  .mobile-cta-bar a {
    background: var(--brand); color: #fff;
    padding: 9px 18px; border-radius: 100px;
    font-size: 13px; font-weight: 600;
  }

  .article-page { margin-bottom: 80px; }

  /* Mobile menu toggle */
  .menu-toggle { display: flex !important; }
}

.menu-toggle {
  display: none;
  border: 1px solid var(--border); background: var(--bg-soft);
  width: 36px; height: 36px; border-radius: 8px;
  align-items: center; justify-content: center;
  color: var(--text);
}

/* Mobile drawer */
.mobile-drawer {
  position: fixed; inset: 0; z-index: 100;
  background: rgba(2,6,23,0.92);
  backdrop-filter: blur(8px);
  display: flex; flex-direction: column;
  padding: 64px 24px 24px;
}
.mobile-drawer__close {
  position: absolute; top: 16px; right: 16px;
  width: 36px; height: 36px; border-radius: 8px;
  background: var(--bg-soft); border: 1px solid var(--border);
  color: var(--text); font-size: 18px;
}
.mobile-drawer a, .mobile-drawer button {
  display: block; padding: 14px 16px;
  font-size: 16px; color: var(--text-2);
  border-radius: 8px; margin-bottom: 4px;
  background: transparent; border: 0; text-align: left;
  width: 100%;
}
.mobile-drawer a:hover, .mobile-drawer button:hover { background: var(--bg-soft); color: var(--text); }

/* ============ FOOTER (matches main site) ============ */
.footer {
  border-top: 1px solid var(--border);
  background: rgba(0,0,0,0.2);
  padding: 56px 0 32px;
  margin-top: 40px;
}
.footer__grid {
  display: grid; grid-template-columns: 1.4fr 1fr 1fr 1fr;
  gap: 40px;
}
.footer__brand { color: var(--text-3); font-size: 13px; line-height: 1.7; max-width: 320px; }
.footer__col h4 {
  font-size: 12px; font-weight: 600; color: var(--text);
  letter-spacing: 0.08em; text-transform: uppercase;
  margin: 0 0 14px;
}
.footer__col ul { list-style: none; padding: 0; margin: 0; }
.footer__col li { font-size: 13px; margin-bottom: 10px; }
.footer__col a { color: var(--text-3); }
.footer__col a:hover { color: var(--text); }
.footer__bottom {
  display: flex; justify-content: space-between;
  margin-top: 40px; padding-top: 24px;
  border-top: 1px solid var(--divider);
  font-size: 12px; color: var(--text-4);
}

@media (max-width: 900px) {
  .footer__grid { grid-template-columns: 1fr 1fr; gap: 32px; }
  .footer__bottom { flex-direction: column; gap: 8px; }
}

/* fade-in */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}
.help-header, .layout, .article-page { animation: fadeUp .5s cubic-bezier(.2,.7,.3,1) both; }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation: none !important; transition: none !important; }
}

/* ===== SITE HEADER（主站融合导航）===== */
.site-header {
  position: sticky; top: 0; z-index: 100;
  background: rgba(2,6,23,0.92);
  backdrop-filter: saturate(180%) blur(16px);
  -webkit-backdrop-filter: saturate(180%) blur(16px);
  border-bottom: 1px solid var(--border);
}
.site-header__inner {
  display: flex; align-items: center; gap: 32px;
  height: 64px;
}
.site-logo {
  display: flex; align-items: center; gap: 10px;
  font-size: 18px; font-weight: 700; color: var(--text);
  letter-spacing: -0.01em; flex-shrink: 0;
  text-decoration: none;
}
.site-logo__mark {
  width: 32px; height: 32px; border-radius: 8px;
  background: linear-gradient(135deg, #3b82f6 0%, #1e3a8a 100%);
  position: relative; flex-shrink: 0;
  box-shadow: 0 2px 8px rgba(59,130,246,0.35);
}
.site-logo__mark::after {
  content: ""; position: absolute; inset: 9px;
  background: #fff; border-radius: 50%;
  clip-path: polygon(35% 25%, 35% 75%, 75% 50%);
}
.site-nav { display: flex; gap: 2px; flex: 1; }
.site-nav__link {
  padding: 8px 14px; border-radius: 8px;
  font-size: 14px; font-weight: 500; color: var(--text-3);
  transition: all .15s; text-decoration: none;
}
.site-nav__link:hover { background: var(--bg-soft); color: var(--text); }
.site-nav__link.is-active { color: var(--brand); background: var(--brand-soft); }
.site-header__right { display: flex; align-items: center; gap: 8px; margin-left: auto; }
.lang-switch { display: flex; background: var(--bg-soft); border-radius: 8px; padding: 3px; }
.lang-switch__btn {
  padding: 4px 10px; border-radius: 6px; border: none;
  font-size: 12px; font-weight: 500; color: var(--text-3);
  background: transparent; cursor: pointer; transition: all .12s;
}
.lang-switch__btn.is-active { background: var(--brand); color: #fff; }
.btn-primary {
  padding: 8px 16px; border-radius: 8px; font-size: 13px; font-weight: 600;
  color: var(--text-2); border: 1px solid var(--border);
  background: transparent; text-decoration: none; transition: all .15s;
  display: inline-block;
}
.btn-primary:hover { color: var(--text); border-color: rgba(255,255,255,.2); }
.btn-primary--filled { background: var(--brand); color: #fff; border-color: var(--brand); }
.btn-primary--filled:hover { background: var(--brand-hover); }

/* ===== HELP CENTER HERO ===== */
.help-center-hero {
  padding: 48px 0 40px;
  border-bottom: 1px solid var(--border);
  margin-bottom: 40px;
}
.help-center-hero h1 {
  font-size: 36px; font-weight: 700; letter-spacing: -0.02em;
  margin: 0 0 12px; color: var(--text);
}
.help-center-hero p { font-size: 16px; color: var(--text-3); margin: 0; max-width: 600px; }

/* ===== HELP LAYOUT ===== */
.help-layout {
  display: grid;
  grid-template-columns: 240px 1fr;
  gap: 48px;
  padding-bottom: 80px;
  align-items: start;
}

/* ===== LEFT SIDEBAR ===== */
.left-sidebar { position: sticky; top: 80px; }
.sidebar-search {
  position: relative; margin-bottom: 28px;
}
.sidebar-search__icon {
  position: absolute; left: 12px; top: 50%; transform: translateY(-50%);
  width: 16px; height: 16px; color: var(--text-4); pointer-events: none;
}
.sidebar-search__input {
  width: 100%; padding: 10px 12px 10px 36px;
  background: var(--bg-soft); border: 1px solid var(--border);
  border-radius: 8px; color: var(--text); font-size: 13px;
  font-family: inherit; outline: none; transition: all .15s;
  box-sizing: border-box;
}
.sidebar-search__input:focus { border-color: var(--brand); background: var(--brand-soft); }
.sidebar-search__input::placeholder { color: var(--text-4); }

.sidebar-section { margin-bottom: 28px; }
.sidebar-section__title {
  font-size: 11px; font-weight: 600; color: var(--text-4);
  letter-spacing: 0.08em; text-transform: uppercase;
  margin-bottom: 10px;
}

/* 分类列表 */
.sidebar-catlist { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 2px; }
.sidebar-catlist__item {
  display: flex; align-items: center; gap: 8px;
  width: 100%; padding: 8px 10px; border-radius: 7px;
  font-size: 13px; color: var(--text-3);
  background: transparent; border: none; cursor: pointer;
  transition: all .12s; text-align: left;
}
.sidebar-catlist__item:hover { background: var(--bg-soft); color: var(--text); }
.sidebar-catlist__item.is-active { background: var(--brand-soft); color: var(--brand); font-weight: 500; }
.sidebar-catlist__count {
  margin-left: auto; font-size: 11px;
  background: var(--bg-elev); color: var(--text-4);
  padding: 1px 7px; border-radius: 10px;
}
.sidebar-catlist__dot {
  width: 8px; height: 8px; border-radius: 50%; flex-shrink: 0;
}
.dot--yt { background: #f87171; }
.dot--sp { background: #4ade80; }
.dot--ch { background: #c084fc; }

/* 热门文章 */
.sidebar-hotlist { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 4px; }
.sidebar-hotlist__item {
  display: flex; align-items: flex-start; gap: 10px;
  width: 100%; padding: 8px 10px; border-radius: 7px;
  background: transparent; border: none; cursor: pointer;
  transition: background .12s; text-align: left;
}
.sidebar-hotlist__item:hover { background: var(--bg-soft); }
.sidebar-hotlist__num {
  font-size: 11px; font-weight: 700; color: var(--text-4);
  font-family: var(--mono); flex-shrink: 0; line-height: 1.6;
}
.sidebar-hotlist__title { font-size: 12px; color: var(--text-3); line-height: 1.5; }

/* CTA 卡片（侧边栏） */
.sidebar-cta-card {
  display: block; padding: 14px;
  background: linear-gradient(135deg, rgba(59,130,246,0.08) 0%, rgba(168,85,247,0.05) 100%);
  border: 1px solid var(--border); border-radius: 10px;
  margin-bottom: 8px; transition: all .2s; text-decoration: none;
}
.sidebar-cta-card:hover { border-color: rgba(59,130,246,.4); transform: translateY(-2px); box-shadow: 0 6px 20px rgba(0,0,0,.2); }
.sidebar-cta-card__head { display: flex; align-items: center; justify-content: space-between; margin-bottom: 6px; }
.sidebar-cta-card__tag {
  font-size: 10px; font-weight: 600; padding: 2px 8px; border-radius: 100px;
}
.tag--yt { background: rgba(239,68,68,.15); color: #f87171; }
.tag--sp { background: rgba(34,197,94,.15); color: #4ade80; }
.tag--ch { background: rgba(168,85,247,.15); color: #c084fc; }
.sidebar-cta-card__badge {
  font-size: 10px; font-weight: 700; padding: 2px 6px; border-radius: 4px;
  background: rgba(251,191,36,.15); color: #fbbf24; border: 1px solid rgba(251,191,36,.3);
}
.sidebar-cta-card__tagline { font-size: 12px; color: var(--text-3); margin-bottom: 6px; }
.sidebar-cta-card__price { font-size: 12px; color: var(--text-4); }
.sidebar-cta-card__price strong { color: var(--brand); font-size: 14px; font-weight: 700; }

/* ===== MAIN CONTENT ===== */
.help-main { min-width: 0; }

/* 文章卡片（新样式） */
.article-grid { display: flex; flex-direction: column; gap: 16px; }
.article-item {
  display: block; padding: 24px;
  background: var(--bg-card); border: 1px solid var(--border);
  border-radius: 12px; text-decoration: none;
  transition: all .2s; cursor: pointer;
}
.article-item:hover { border-color: rgba(59,130,246,.3); transform: translateY(-2px); box-shadow: 0 8px 24px rgba(0,0,0,.2); }
.article-item__top { display: flex; align-items: center; gap: 10px; margin-bottom: 12px; }
.article-item__cat {
  font-size: 11px; font-weight: 600; padding: 3px 10px; border-radius: 100px;
}
.article-item__cat--yt { background: rgba(239,68,68,.15); color: #f87171; }
.article-item__cat--sp { background: rgba(34,197,94,.15); color: #4ade80; }
.article-item__cat--ch { background: rgba(168,85,247,.15); color: #c084fc; }
.article-item__kind {
  font-size: 11px; color: var(--text-4); border: 1px solid var(--border);
  padding: 2px 8px; border-radius: 100px;
}
.article-item__title {
  font-size: 18px; font-weight: 600; color: var(--text);
  margin: 0 0 8px; letter-spacing: -0.01em; line-height: 1.4;
  transition: color .15s;
}
.article-item:hover .article-item__title { color: var(--brand); }
.article-item__excerpt { font-size: 14px; color: var(--text-3); line-height: 1.6; margin: 0 0 16px;
  display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
.article-item__meta { display: flex; align-items: center; gap: 16px; font-size: 12px; color: var(--text-4); }
.article-item__meta span { display: flex; align-items: center; gap: 4px; }

/* 文章详情页包装器 */
.article-page-wrapper { padding-bottom: 80px; }

/* ===== MOBILE ===== */
@media (max-width: 768px) {
  .help-layout { grid-template-columns: 1fr; }
  .left-sidebar { position: static; display: none; }
  .help-center-hero h1 { font-size: 24px; }
  .site-nav { display: none; }
  .lang-switch { display: none; }
}

/* ===== 文章卡片封面渐变（无图时自动生成） ===== */
.article-item__cover {
  height: 140px; border-radius: 8px; margin-bottom: 16px;
  background: linear-gradient(135deg, #1a2540 0%, #243050 100%);
  position: relative; overflow: hidden;
}
.article-item__cover--yt {
  background: linear-gradient(135deg, rgba(239,68,68,0.3) 0%, rgba(23,143,198,0.2) 100%);
}
.article-item__cover--sp {
  background: linear-gradient(135deg, rgba(34,197,94,0.3) 0%, rgba(23,143,198,0.2) 100%);
}
.article-item__cover--ch {
  background: linear-gradient(135deg, rgba(168,85,247,0.3) 0%, rgba(23,143,198,0.2) 100%);
}
.article-item__cover-label {
  position: absolute; bottom: 12px; left: 16px;
  font-size: 28px; font-weight: 800; color: rgba(255,255,255,0.12);
  letter-spacing: -0.03em; font-family: var(--sans);
}

/* ===== 橙色 CTA 按钮（对齐主站注册按钮） ===== */
.btn-primary--filled {
  background: linear-gradient(90deg, var(--accent) 0%, #FB923C 100%) !important;
  border-color: var(--accent) !important;
  color: #fff !important;
  box-shadow: 0 4px 14px rgba(249,115,22,0.35);
}
.btn-primary--filled:hover {
  background: linear-gradient(90deg, var(--accent-hover) 0%, var(--accent) 100%) !important;
  transform: translateY(-1px);
  box-shadow: 0 6px 20px rgba(249,115,22,0.45);
}

/* ===== 侧边栏 CTA 卡片——"立即购买"橙色按钮 ===== */
.sidebar-cta-card__btn {
  display: flex; align-items: center; justify-content: space-between;
  margin-top: 10px; padding: 8px 12px; border-radius: 6px;
  background: var(--accent); color: #fff;
  font-size: 12px; font-weight: 600;
  transition: all .15s;
}
.sidebar-cta-card:hover .sidebar-cta-card__btn {
  background: var(--accent-hover);
}

/* ===== Hero 区域加光晕 ===== */
.help-center-hero {
  background: radial-gradient(ellipse 80% 100% at 50% -20%, rgba(23,143,198,0.15) 0%, transparent 70%);
}
.help-center-hero h1 {
  background: linear-gradient(135deg, #F1F5F9 0%, #178fc6 100%);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* ===== 导航 logo 图标颜色对齐主站 ===== */
.site-logo__mark {
  background: linear-gradient(135deg, #178fc6 0%, #0F172A 100%) !important;
  box-shadow: 0 2px 8px rgba(23,143,198,0.4) !important;
}

/* ===== LOGO 重设计 ===== */
.site-logo { display: flex; align-items: center; gap: 10px; text-decoration: none; }
.site-logo__icon { width: 36px; height: 36px; flex-shrink: 0; }
.site-logo__text { display: flex; flex-direction: column; line-height: 1; }
.site-logo__name { font-size: 16px; font-weight: 700; color: var(--text); letter-spacing: -0.01em; }
.site-logo__sub { font-size: 10px; font-weight: 500; color: var(--brand); letter-spacing: 0.04em; margin-top: 2px; }

/* ===== NAV 按钮改为 button ===== */
.site-nav { display: flex; gap: 2px; flex: 1; justify-content: center; }
.site-nav__link {
  padding: 8px 14px; border-radius: 8px; border: none;
  font-size: 14px; font-weight: 500; color: var(--text-3);
  background: transparent; cursor: pointer; transition: all .15s;
}
.site-nav__link:hover { background: var(--bg-soft); color: var(--text); }
.site-nav__link.is-active { color: var(--brand); background: var(--brand-soft); }

/* ===== 购买按钮 ===== */
.btn-buy {
  padding: 9px 18px; border-radius: 8px;
  background: linear-gradient(90deg, var(--accent) 0%, #FB923C 100%);
  color: #fff; font-size: 13px; font-weight: 700;
  text-decoration: none; white-space: nowrap;
  box-shadow: 0 4px 14px rgba(249,115,22,0.35);
  transition: all .15s;
}
.btn-buy:hover { transform: translateY(-1px); box-shadow: 0 6px 20px rgba(249,115,22,0.45); }

/* ===== 紧凑文章行 ===== */
.article-row {
  display: flex; align-items: center; gap: 16px;
  padding: 18px 20px; border-radius: 10px;
  background: var(--bg-card); border: 1px solid var(--border);
  cursor: pointer; transition: all .18s; margin-bottom: 8px;
}
.article-row:hover { border-color: var(--brand); background: var(--bg-elev); transform: translateX(4px); }
.article-row__stripe { width: 3px; height: 44px; border-radius: 2px; flex-shrink: 0; }
.stripe--yt { background: #f87171; }
.stripe--sp { background: #4ade80; }
.stripe--ch { background: #c084fc; }
.article-row__body { flex: 1; min-width: 0; }
.article-row__tags { display: flex; align-items: center; gap: 6px; margin-bottom: 6px; }
.article-row__cat {
  font-size: 11px; font-weight: 600; padding: 2px 8px; border-radius: 100px;
}
.cat--yt { background: rgba(239,68,68,.15); color: #f87171; }
.cat--sp { background: rgba(34,197,94,.15); color: #4ade80; }
.cat--ch { background: rgba(168,85,247,.15); color: #c084fc; }
.article-row__kind {
  font-size: 11px; color: var(--text-4); border: 1px solid var(--border);
  padding: 1px 7px; border-radius: 100px;
}
.article-row__featured {
  font-size: 11px; color: #fbbf24; border: 1px solid rgba(251,191,36,.3);
  background: rgba(251,191,36,.1); padding: 1px 7px; border-radius: 100px;
}
.article-row__title {
  font-size: 16px; font-weight: 600; color: var(--text);
  margin: 0 0 6px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
  letter-spacing: -0.01em;
}
.article-row:hover .article-row__title { color: var(--brand); }
.article-row__meta { font-size: 12px; color: var(--text-4); display: flex; gap: 6px; }
.article-row__arrow { color: var(--text-4); font-size: 16px; flex-shrink: 0; transition: all .18s; }
.article-row:hover .article-row__arrow { color: var(--brand); transform: translateX(4px); }

/* ===== 文章页 ===== */
.article-content { min-width: 0; }
.article-page__header { padding: 32px 0 24px; border-bottom: 1px solid var(--border); margin-bottom: 32px; }
.article-page__tags { margin-bottom: 12px; }
.article-page__title {
  font-size: 30px; font-weight: 700; letter-spacing: -0.02em;
  color: var(--text); margin: 0 0 12px; line-height: 1.3;
}
.article-page__meta { font-size: 13px; color: var(--text-4); display: flex; gap: 8px; }
.article-page__body { font-size: 15px; line-height: 1.8; color: var(--text-2); }
.article-page__body h2 { font-size: 20px; font-weight: 600; color: var(--text); margin: 32px 0 12px; }
.article-page__body p { margin: 0 0 16px; }
.article-callout {
  background: var(--brand-soft); border: 1px solid var(--brand);
  border-radius: 8px; padding: 16px 20px; margin: 24px 0;
}
.article-callout strong { color: var(--brand); display: block; margin-bottom: 4px; }

/* 文章底部 CTA */
.article-page__cta { margin-top: 48px; padding-top: 32px; border-top: 1px solid var(--border); display: flex; flex-direction: column; gap: 10px; }
.article-cta-card {
  display: flex; align-items: center; justify-content: space-between;
  padding: 16px 20px; border-radius: 10px;
  background: var(--bg-card); border: 1px solid var(--border);
  text-decoration: none; transition: all .18s;
}
.article-cta-card:hover { border-color: var(--accent); transform: translateY(-2px); box-shadow: 0 6px 20px rgba(249,115,22,.15); }
.article-cta-card__left { display: flex; align-items: center; gap: 12px; }
.article-cta-card__tagline { font-size: 14px; color: var(--text-2); }
.article-cta-card__right { display: flex; align-items: center; gap: 16px; }
.article-cta-card__price { font-size: 13px; color: var(--text-3); }
.article-cta-card__price strong { color: var(--accent); font-size: 16px; font-weight: 700; }
.article-cta-card__btn {
  padding: 8px 16px; border-radius: 7px;
  background: var(--accent); color: #fff;
  font-size: 13px; font-weight: 600;
  white-space: nowrap;
}

/* 相关文章 */
.article-page__related { margin-top: 40px; }
.article-page__related-title { font-size: 16px; font-weight: 600; color: var(--text); margin-bottom: 12px; }

/* 面包屑 */
.breadcrumb { display: flex; align-items: center; gap: 6px; padding: 16px 0; font-size: 13px; color: var(--text-4); }
.bc-link { background: none; border: none; color: var(--text-4); cursor: pointer; font-size: 13px; padding: 0; }
.bc-link:hover { color: var(--brand); }
.bc-sep { color: var(--border); }
.bc-current { color: var(--text-3); }

/* ===== 移动端 ===== */
@media (max-width: 900px) {
  .site-nav { display: none; }
  .help-layout { grid-template-columns: 1fr; }
  .left-sidebar { display: none; }
}