/* =====================================================================
 * /help 路由 · 帮助与隐私中心
 *
 * 视觉系统沿用 /app 工作台的 --wb-* 令牌 + 深色玻璃拟态。
 * 类名保持与原 HTML 一致，只重写视觉，不改 DOM 结构。
 * ===================================================================== */

:root {
  /* — 沿用 workbench-prototype.css 的令牌 — */
  --wb-bg: #05080f;
  --wb-panel: rgba(13, 20, 34, 0.72);
  --wb-panel-solid: #0b1220;
  --wb-panel-soft: rgba(8, 14, 25, 0.58);
  --wb-line: rgba(56, 189, 248, 0.14);
  --wb-line-strong: rgba(56, 189, 248, 0.34);
  --wb-cyan: #22d3ee;
  --wb-sky: #38bdf8;
  --wb-indigo: #6366f1;
  --wb-success: #34d399;
  --wb-text: #e7eef8;
  --wb-muted: #8296b0;
  --wb-muted-2: #5b6b82;
  --wb-gradient: linear-gradient(135deg, #22d3ee 0%, #38bdf8 45%, #6366f1 100%);
  --wb-radius: 18px;

  /* — 旧版别名（避免破坏现有 i18n/JS 引用） — */
  --ink: var(--wb-text);
  --muted: var(--wb-muted);
  --paper: var(--wb-bg);
  --white: var(--wb-panel-solid);
  --green: var(--wb-cyan);
  --green-dark: var(--wb-sky);
  --acid: var(--wb-cyan);
  --line: var(--wb-line);

  /* — 动效 — */
  --motion-ease-out: cubic-bezier(0.23, 1, 0.32, 1);
  --motion-reveal-duration: 600ms;
  --motion-stagger: 60ms;

  /* — 内容容器上限(与首页 .container 宽度一致) — */
  --help-content-max: 1180px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 90px; }

body {
  margin: 0;
  color: var(--wb-text);
  background-color: var(--wb-bg);
  font-family: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", system-ui, sans-serif;
  position: relative;
}

body::before,
body::after {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
}

/* 蓝图网格背景 */
body::before {
  background-image:
    linear-gradient(rgba(56, 189, 248, 0.045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(56, 189, 248, 0.045) 1px, transparent 1px),
    linear-gradient(rgba(56, 189, 248, 0.075) 1px, transparent 1px),
    linear-gradient(90deg, rgba(56, 189, 248, 0.075) 1px, transparent 1px);
  background-size: 36px 36px, 36px 36px, 180px 180px, 180px 180px;
  -webkit-mask-image: radial-gradient(ellipse 94% 86% at 50% 0%, #000 42%, transparent 100%);
  mask-image: radial-gradient(ellipse 94% 86% at 50% 0%, #000 42%, transparent 100%);
}

/* 三个柔光晕染（与 workbench 一致） */
body::after {
  background:
    radial-gradient(circle at 4% -8%, rgba(34, 211, 238, 0.16), transparent 29%),
    radial-gradient(circle at 102% 92%, rgba(99, 102, 241, 0.14), transparent 31%),
    radial-gradient(circle at 56% 45%, rgba(56, 189, 248, 0.055), transparent 26%);
}

a { color: inherit; text-decoration: none; }
h1, h2, h3, p { margin-top: 0; }
main { overflow-x: hidden; position: relative; z-index: 1; }

::selection { background: rgba(34, 211, 238, 0.26); }

::-webkit-scrollbar { width: 10px; height: 10px; }
::-webkit-scrollbar-thumb {
  border: 2px solid var(--wb-bg);
  border-radius: 8px;
  background: rgba(56, 189, 248, 0.2);
}

/* 玻璃卡片基类（供多处复用） */
.glass-surface {
  border: 1px solid var(--wb-line);
  background: var(--wb-panel);
  -webkit-backdrop-filter: blur(14px);
  backdrop-filter: blur(14px);
  border-radius: var(--wb-radius);
}

/* =====================================================================
 * 顶栏
 * ===================================================================== */

/* 容器(与首页 .container 同款) */
.container {
  width: min(calc(100% - 48px), var(--help-content-max));
  margin: 0 auto;
}

.site-header {
  border-bottom: 1px solid var(--wb-line);
  background: rgba(6, 10, 18, 0.78);
  -webkit-backdrop-filter: blur(18px);
  backdrop-filter: blur(18px);
  position: sticky;
  top: 0;
  z-index: 20;
}
.nav {
  min-height: 76px;
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 28px;
}

.brand {
  width: max-content;
  display: inline-flex;
  align-items: center;
  gap: 11px;
  color: var(--wb-text);
  font-size: 15px;
  font-weight: 800;
  letter-spacing: 0.04em;
}
.brand-copy {
  display: flex;
  flex-direction: column;
  line-height: 1.2;
}
.brand-name { font-size: 15px; }
.brand-subtitle {
  margin-top: 3px;
  color: var(--wb-muted);
  font-size: 10px;
  font-weight: 600;
  letter-spacing: 0.08em;
}

.brand-mark {
  width: 54px;
  height: 54px;
  display: grid;
  place-items: center;
  flex: 0 0 auto;
  filter: drop-shadow(0 0 12px rgba(34, 211, 238, 0.24));
}
.brand-logo { grid-area: 1 / 1; width: 100%; height: 100%; display: block; object-fit: contain; }
.brand-logo-light { display: none; }

.nav-links {
  display: flex;
  align-items: center;
  gap: 28px;
  color: var(--wb-muted);
  font-size: 13px;
  font-weight: 650;
}
.nav-links a {
  transition: color 180ms ease;
}
.nav-links a:hover {
  color: var(--wb-cyan);
}
.footer-links a {
  color: var(--wb-muted);
  transition: color 0.2s;
}
.footer-links a:hover {
  color: var(--wb-cyan);
}

.header-actions {
  justify-self: end;
  display: flex;
  align-items: center;
  gap: 8px;
}

/* 工具按钮（语言 / 主题） */
.utility-toggle {
  width: 38px;
  height: 38px;
  display: inline-grid;
  place-items: center;
  border: 1px solid var(--wb-line);
  border-radius: 10px;
  color: var(--wb-muted);
  background: rgba(255, 255, 255, 0.03);
  cursor: pointer;
  font: 600 13px/1 system-ui, sans-serif;
  transition: border-color 0.2s, color 0.2s, background 0.2s, transform 0.18s;
}
.utility-toggle.language {
  width: 52px;
  grid-template-columns: 15px auto;
  gap: 3px;
}
.utility-toggle b { font-size: 10px; }
.utility-toggle:hover {
  border-color: var(--wb-line-strong);
  color: var(--wb-cyan);
  box-shadow: 0 0 16px rgba(34, 211, 238, 0.1);
  transform: translateY(-1px);
}
.theme-icon {
  width: 18px;
  height: 18px;
  display: none;
}

body.theme-light .theme-icon-moon { display: block; }
body.theme-dark .theme-icon-sun { display: block; }

/* 登录按钮 */
.help-user-button {
  min-height: 38px;
  padding: 0 14px;
  border: 1px solid var(--wb-line);
  border-radius: 10px;
  color: var(--wb-muted);
  background: rgba(255, 255, 255, 0.03);
  font-size: 12px;
  white-space: nowrap;
  cursor: pointer;
  transition: border-color 0.2s, color 0.2s, transform 0.18s;
}
.help-user-button:hover {
  border-color: var(--wb-line-strong);
  color: var(--wb-cyan);
  transform: translateY(-1px);
}
.help-user-menu { position: relative; }
.help-user-button { display: inline-flex; align-items: center; gap: 7px; max-width: 150px; }
.help-user-avatar {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 24px;
  height: 24px;
  flex-shrink: 0;
  overflow: hidden;
  border-radius: 50%;
  background: var(--wb-gradient);
  color: #04121c;
  font-size: 11px;
  font-weight: 700;
}
.help-user-avatar img { display: block; width: 100%; height: 100%; object-fit: cover; }
.help-user-avatar img[hidden] { display: none; }
.help-user-name { overflow: hidden; text-overflow: ellipsis; }
.help-user-dropdown {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  z-index: 30;
  min-width: 120px;
  padding: 5px;
  border: 1px solid var(--wb-line);
  border-radius: 10px;
  background: var(--wb-panel-solid);
  -webkit-backdrop-filter: blur(14px);
  backdrop-filter: blur(14px);
  box-shadow: 0 14px 30px rgba(0, 0, 0, 0.4);
}
.help-user-dropdown button {
  width: 100%;
  padding: 9px 10px;
  border: 0;
  border-radius: 5px;
  color: #f87171;
  background: transparent;
  text-align: left;
  cursor: pointer;
}
.help-user-dropdown button:hover { background: rgba(248, 113, 113, 0.10); }

/* 返回工作台 CTA */
.app-link {
  border: 1px solid var(--wb-line);
  border-radius: 10px;
  padding: 10px 16px;
  color: var(--wb-cyan);
  background: rgba(34, 211, 238, 0.06);
  font-size: 12px;
  font-weight: 700;
  white-space: nowrap;
  transition: border-color 0.2s, background 0.2s, color 0.2s, transform 0.2s;
  display: inline-flex;
  align-items: center;
  gap: 6px;
}
.app-link:hover {
  border-color: var(--wb-cyan);
  background: rgba(34, 211, 238, 0.14);
  color: var(--wb-cyan);
  box-shadow: 0 0 16px rgba(34, 211, 238, 0.16);
  transform: translateY(-1px);
}

/* =====================================================================
 * Hero 区
 * ===================================================================== */

.hero {
  min-height: 680px;
  padding: clamp(70px, 10vw, 140px) 0 90px;
  position: relative;
  overflow: hidden;
}
.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.45fr) minmax(300px, 0.55fr);
  gap: clamp(32px, 5vw, 80px);
  align-items: center;
}

/* 右上角柔光圈（替代原蓝色环） */
.hero::after {
  content: "";
  position: absolute;
  width: 480px;
  height: 480px;
  border: 1px solid var(--wb-line);
  border-radius: 50%;
  right: -240px;
  top: 60px;
  box-shadow:
    0 0 0 70px rgba(34, 211, 238, 0.045),
    0 0 0 140px rgba(34, 211, 238, 0.025);
  pointer-events: none;
}

.eyebrow {
  margin: 0 0 24px;
  color: var(--wb-cyan);
  font: 750 11px/1.2 ui-monospace, SFMono-Regular, Menlo, monospace;
  letter-spacing: 0.13em;
}
.eyebrow.light { color: var(--wb-cyan); }

.hero h1 {
  margin-bottom: 28px;
  max-width: 800px;
  font-size: clamp(46px, 5.6vw, 78px);
  line-height: 1.08;
  letter-spacing: -0.055em;
  font-weight: 790;
  color: var(--wb-text);
  text-wrap: balance;
}
.hero h1 em {
  background: var(--wb-gradient);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  font-style: normal;
}

.system-line {
  display: flex;
  align-items: center;
  gap: 9px;
  margin: -6px 0 24px;
  color: var(--wb-muted-2);
  font: 650 10px/1.2 ui-monospace, SFMono-Regular, Menlo, monospace;
  letter-spacing: 0.1em;
}
.system-line span {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--wb-cyan);
  box-shadow: 0 0 12px rgba(34, 211, 238, 0.85);
  animation: hp-blink 1.6s ease-in-out infinite;
}
@keyframes hp-blink {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.35; }
}

.lead {
  max-width: 650px;
  color: var(--wb-muted);
  font-size: clamp(17px, 1.5vw, 21px);
  line-height: 1.85;
}

.hero-actions {
  display: flex;
  align-items: center;
  gap: 30px;
  margin-top: 40px;
}

/* 主按钮：使用 --wb-gradient + sheen 高光动画 */
.primary-button {
  position: relative;
  overflow: hidden;
  padding: 14px 24px;
  color: #04121c;
  background: var(--wb-gradient);
  border: 0;
  border-radius: 10px;
  box-shadow: 0 4px 20px rgba(34, 211, 238, 0.28);
  font-size: 14px;
  font-weight: 750;
  cursor: pointer;
  transition: transform 0.2s, box-shadow 0.2s;
  display: inline-flex;
  align-items: center;
  gap: 7px;
  text-decoration: none;
}
.primary-button:hover {
  background: var(--wb-gradient);
  transform: translateY(-2px);
  box-shadow: 0 6px 26px rgba(34, 211, 238, 0.42);
  color: #04121c;
}
.primary-button::after {
  content: "";
  position: absolute;
  top: 0;
  left: -85%;
  width: 48%;
  height: 100%;
  background: linear-gradient(100deg, transparent, rgba(255, 255, 255, 0.42), transparent);
  transform: skewX(-20deg);
  animation: hp-sheen 3.6s ease-in-out infinite;
  pointer-events: none;
}
@keyframes hp-sheen {
  0%, 60% { left: -85%; }
  100% { left: 165%; }
}

.text-link {
  font-size: 14px;
  font-weight: 700;
  border-bottom: 1px solid var(--wb-text);
  padding-bottom: 4px;
  color: var(--wb-text);
  transition: color 0.2s, border-color 0.2s;
}
.text-link:hover {
  color: var(--wb-cyan);
  border-bottom-color: var(--wb-cyan);
}

/* Hero 侧卡（玻璃面板） */
.hero-card {
  position: relative;
  z-index: 1;
  padding: 30px;
  color: var(--wb-text);
  background: var(--wb-panel);
  -webkit-backdrop-filter: blur(14px);
  backdrop-filter: blur(14px);
  border: 1px solid var(--wb-line);
  border-radius: var(--wb-radius);
  box-shadow:
    0 16px 60px rgba(0, 0, 0, 0.4),
    0 0 24px rgba(34, 211, 238, 0.06);
}
.hero-card::before {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  background: linear-gradient(135deg, rgba(34, 211, 238, 0.08), transparent 42%);
  pointer-events: none;
}

.card-index {
  display: inline-block;
  margin-bottom: 30px;
  padding: 5px 11px;
  color: #04121c;
  background: var(--wb-gradient);
  border-radius: 999px;
  font-size: 11px;
  font-weight: 800;
  letter-spacing: 0.3px;
  box-shadow: 0 0 12px rgba(34, 211, 238, 0.32);
}
.hero-card h2 {
  font-size: clamp(20px, 2vw, 24px);
  line-height: 1.35;
  color: var(--wb-text);
}
.hero-card h2:lang(zh) {
  white-space: nowrap;
}
.hero-card > p {
  color: var(--wb-muted);
  font-size: 14px;
  line-height: 1.8;
  margin-bottom: 30px;
}
.format-row {
  display: grid;
  grid-template-columns: 90px 1fr;
  gap: 15px;
  padding: 16px 0;
  border-top: 1px solid var(--wb-line);
  font-size: 12px;
}
.format-row span { color: var(--wb-muted-2); }
.format-row strong {
  line-height: 1.6;
  color: var(--wb-text);
  font-family: "Rajdhani", "PingFang SC", "Microsoft YaHei", sans-serif;
  letter-spacing: 0.4px;
}

/* =====================================================================
 * 工程视觉（机械图纸）
 * ===================================================================== */

.engineering-visual {
  margin: 0;
  padding: 0 clamp(22px, 8vw, 128px) clamp(80px, 9vw, 130px);
}
.engineering-visual-frame {
  position: relative;
  overflow: hidden;
  border: 1px solid var(--wb-line);
  border-radius: var(--wb-radius);
  background: var(--wb-panel-solid);
  box-shadow: 0 28px 80px rgba(0, 0, 0, 0.4);
}
.engineering-visual-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, transparent 62%, rgba(6, 11, 14, 0.28));
  pointer-events: none;
}
.engineering-visual img {
  width: 100%;
  height: auto;
  display: block;
  aspect-ratio: 16 / 8.8;
  object-fit: cover;
  object-position: center;
}
.visual-corner { display: none; }
.engineering-visual figcaption {
  display: grid;
  grid-template-columns: minmax(280px, 0.8fr) minmax(300px, 1.2fr);
  gap: 40px;
  padding: 22px 0;
  border-bottom: 1px solid var(--wb-line);
}
.engineering-visual figcaption span {
  display: flex;
  align-items: baseline;
  gap: 18px;
}
.engineering-visual figcaption b {
  color: var(--wb-cyan);
  font: 750 10px ui-monospace, SFMono-Regular, Menlo, monospace;
  letter-spacing: 0.1em;
  white-space: nowrap;
}
.engineering-visual figcaption strong {
  font-size: 15px;
  color: var(--wb-text);
}
.engineering-visual figcaption p {
  margin: 0;
  color: var(--wb-muted);
  font-size: 13px;
  line-height: 1.7;
}

/* =====================================================================
 * Section 通用
 * ===================================================================== */

.section {
  padding: clamp(80px, 10vw, 150px) 0;
  border-top: 1px solid var(--wb-line);
}
.section-heading { max-width: 650px; }
.section-heading h2,
.privacy-intro h2,
.cta-section h2 {
  margin-bottom: 22px;
  font-size: clamp(38px, 4.6vw, 64px);
  line-height: 1.12;
  letter-spacing: -0.045em;
  color: var(--wb-text);
}
.section-heading > p:last-child {
  color: var(--wb-muted);
  font-size: 16px;
  line-height: 1.8;
}

/* =====================================================================
 * 步骤卡片（四列网格）
 * ===================================================================== */

.steps-grid {
  margin-top: 62px;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  border: 1px solid var(--wb-line);
  border-radius: var(--wb-radius);
  background: var(--wb-panel);
  -webkit-backdrop-filter: blur(14px);
  backdrop-filter: blur(14px);
  box-shadow: 0 26px 70px rgba(0, 0, 0, 0.32), 0 0 30px rgba(34, 211, 238, 0.05);
  overflow: hidden;
  position: relative;
}
.step-card {
  min-height: 310px;
  padding: 28px 26px;
  border-right: 1px solid var(--wb-line);
  transition: background 0.25s, color 0.25s, transform 0.18s;
  position: relative;
}
.step-card:last-child { border-right: 0; }
.step-card::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(34, 211, 238, 0.10), transparent 60%);
  opacity: 0;
  transition: opacity 0.25s;
  pointer-events: none;
}
.step-card:hover {
  background: linear-gradient(150deg, rgba(34, 211, 238, 0.18), rgba(99, 102, 241, 0.10));
  color: var(--wb-text);
  transform: translateY(-2px);
}
.step-card:hover::before { opacity: 1; }
.step-card:hover p { color: var(--wb-text); }

.step-top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 90px;
  position: relative;
  z-index: 1;
}
.step-top > span:last-child {
  font: 700 11px ui-monospace, monospace;
  color: var(--wb-cyan);
}
.step-symbol {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 30px;
  height: 30px;
  color: var(--wb-cyan);
}
.step-symbol svg {
  width: 100%;
  height: 100%;
  display: block;
}
.step-card h3 {
  font-size: 20px;
  margin-bottom: 14px;
  color: var(--wb-text);
  position: relative;
  z-index: 1;
}
.step-card p {
  color: var(--wb-muted);
  font-size: 14px;
  line-height: 1.75;
  margin-bottom: 0;
  position: relative;
  z-index: 1;
  transition: color 0.25s;
}

/* =====================================================================
 * split-section（识别之后）
 * ===================================================================== */

.split-section {
  background: var(--wb-panel-soft);
  border-top: 1px solid var(--wb-line);
}
.split-grid {
  display: grid;
  grid-template-columns: 0.75fr 1.25fr;
  gap: clamp(70px, 12vw, 180px);
}
.sticky-copy {
  align-self: start;
  position: sticky;
  top: 130px;
}
.feature-list article {
  display: grid;
  grid-template-columns: 45px 1fr;
  gap: 24px;
  padding: 34px 0;
  border-top: 1px solid var(--wb-line);
}
.feature-list article:last-child { border-bottom: 1px solid var(--wb-line); }
.feature-list article > span {
  color: var(--wb-cyan);
  font: 750 11px ui-monospace, monospace;
}
.feature-list h3 {
  font-size: 22px;
  margin-bottom: 10px;
  color: var(--wb-text);
}
.feature-list p {
  color: var(--wb-muted);
  font-size: 15px;
  line-height: 1.8;
  margin-bottom: 0;
}

/* =====================================================================
 * 隐私说明 section（深底 + 蓝图网格）
 * ===================================================================== */

.privacy-section {
  padding: clamp(80px, 10vw, 150px) 0;
  color: var(--wb-text);
  background-color: var(--wb-bg);
  background-image:
    linear-gradient(rgba(56, 189, 248, 0.045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(56, 189, 238, 0.045) 1px, transparent 1px);
  background-size: 36px 36px, 36px 36px;
  border-top: 1px solid var(--wb-line);
  position: relative;
}
.privacy-grid {
  display: grid;
  grid-template-columns: minmax(280px, 0.6fr) minmax(0, 1.4fr);
  gap: clamp(60px, 10vw, 150px);
}
.privacy-intro {
  align-self: start;
  position: sticky;
  top: 130px;
}
.privacy-intro > p:last-child {
  color: var(--wb-muted);
  font-size: 13px;
}
.privacy-content { min-width: 0; }
.privacy-content > article {
  padding: 48px 0;
  border-top: 1px solid var(--wb-line);
}
.privacy-content > article:first-child {
  padding-top: 0;
  border-top: 0;
}
.privacy-content h3 {
  font-size: 23px;
  color: var(--wb-text);
}

.data-table > div {
  display: grid;
  grid-template-columns: 160px 1fr;
  gap: 28px;
  padding: 22px 0;
  border-bottom: 1px solid var(--wb-line);
}
.data-table strong {
  color: var(--wb-cyan);
  font-size: 14px;
}
.data-table span,
.policy-note {
  color: var(--wb-muted);
  font-size: 14px;
  line-height: 1.75;
}

.retention-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
}
.retention-grid > div {
  min-height: 235px;
  padding: 25px;
  border: 1px solid var(--wb-line);
  border-radius: var(--wb-radius);
  background: var(--wb-panel);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  transition: transform 0.18s, border-color 0.18s;
}
.retention-grid > div:hover {
  border-color: var(--wb-line-strong);
  transform: translateY(-2px);
}
.retention-grid b {
  font-family: "Rajdhani", "DIN Alternate", sans-serif;
  font-size: 45px;
  letter-spacing: -0.05em;
  color: var(--wb-text);
  background: var(--wb-gradient);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.retention-grid span {
  margin-left: 7px;
  color: var(--wb-cyan);
  font-size: 12px;
}
.retention-grid p {
  margin-top: 35px;
  color: var(--wb-muted);
  font-size: 13px;
  line-height: 1.7;
}

.policy-note {
  margin: 18px 0 0;
  padding: 10px 14px;
  border-left: 2px solid var(--wb-cyan);
  background: rgba(34, 211, 238, 0.06);
  border-radius: 0 8px 8px 0;
}

.delete-block,
.security-note {
  display: grid;
  grid-template-columns: 54px 1fr;
  gap: 22px;
}
.round-icon {
  width: 44px;
  height: 44px;
  display: grid;
  place-items: center;
  color: #04121c;
  background: var(--wb-gradient);
  border-radius: 10px;
  box-shadow: 0 0 20px rgba(34, 211, 238, 0.32);
  font-size: 20px;
}
.delete-block ol {
  margin: 0;
  padding-left: 21px;
  color: var(--wb-muted);
  font-size: 14px;
  line-height: 1.85;
}
.delete-block li + li { margin-top: 14px; }
.delete-block strong { color: var(--wb-text); }

.third-party-grid { display: grid; gap: 10px; }
.third-party-grid > div {
  display: grid;
  grid-template-columns: 36px 1fr;
  gap: 16px;
  padding: 24px;
  border: 1px solid var(--wb-line);
  border-radius: var(--wb-radius);
  background: var(--wb-panel);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  transition: border-color 0.18s, transform 0.18s;
}
.third-party-grid > div:hover {
  border-color: var(--wb-line-strong);
  transform: translateY(-2px);
}
.party-icon {
  width: 30px;
  height: 30px;
  display: grid;
  place-items: center;
  border: 1px solid var(--wb-line);
  border-radius: 8px;
  color: var(--wb-cyan);
  background: rgba(34, 211, 238, 0.10);
  font-size: 12px;
}
.third-party-grid strong {
  display: block;
  margin-bottom: 7px;
  color: var(--wb-text);
}
.third-party-grid p {
  color: var(--wb-muted);
  font-size: 13px;
  line-height: 1.7;
  margin-bottom: 10px;
}
.third-party-grid a {
  color: var(--wb-cyan);
  font-size: 12px;
  font-weight: 700;
}
.third-party-grid a:hover { color: var(--wb-sky); }

.security-note { padding-bottom: 0 !important; }
.shield {
  color: var(--wb-cyan);
  font-size: 38px;
  text-shadow: 0 0 16px rgba(34, 211, 238, 0.5);
}
.security-note p {
  color: var(--wb-muted);
  line-height: 1.8;
  margin: 0;
}

/* =====================================================================
 * FAQ
 * ===================================================================== */

.faq-section {
  background: var(--wb-bg);
  border-top: 1px solid var(--wb-line);
}
.faq-grid {
  display: grid;
  grid-template-columns: 0.65fr 1.35fr;
  gap: clamp(60px, 10vw, 150px);
}
.faq-list {
  border: 1px solid var(--wb-line);
  border-radius: var(--wb-radius);
  background: var(--wb-panel);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  overflow: hidden;
}
.faq-list details { border-top: 1px solid var(--wb-line); }
.faq-list details:first-child { border-top: 0; }
.faq-list summary {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 20px;
  padding: 22px 24px;
  cursor: pointer;
  list-style: none;
  font-size: 17px;
  font-weight: 700;
  color: var(--wb-text);
  transition: background 0.18s;
}
.faq-list summary::-webkit-details-marker { display: none; }
.faq-list summary:hover { background: rgba(34, 211, 238, 0.05); }
.faq-list summary i {
  color: var(--wb-cyan);
  font-size: 22px;
  font-style: normal;
  font-weight: 400;
  transition: transform 0.2s;
  flex-shrink: 0;
}
.faq-list details[open] summary i { transform: rotate(45deg); }
.faq-list details p {
  max-width: 720px;
  padding: 0 24px 22px;
  color: var(--wb-muted);
  font-size: 14px;
  line-height: 1.8;
}

/* =====================================================================
 * CTA section（ready）
 * ===================================================================== */

.cta-section {
  min-height: 480px;
  padding: clamp(80px, 9vw, 130px) 0;
  color: var(--wb-text);
  background:
    radial-gradient(circle at 50% 50%, rgba(34, 211, 238, 0.20), transparent 60%),
    var(--wb-bg);
  position: relative;
  overflow: hidden;
  border-top: 1px solid var(--wb-line);
}
.cta-section::after {
  content: "GO";
  position: absolute;
  right: -20px;
  bottom: -110px;
  background: var(--wb-gradient);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  font-size: 370px;
  font-weight: 900;
  line-height: 1;
  letter-spacing: -0.1em;
  opacity: 0.10;
  pointer-events: none;
}
.cta-section h2 {
  position: relative;
  z-index: 1;
  font-size: clamp(48px, 6vw, 84px);
  color: var(--wb-text);
}
.cta-section h2 em {
  background: var(--wb-gradient);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  font-style: normal;
}
.cta-section .cta-button {
  position: relative;
  z-index: 2;
  display: inline-flex;
  align-items: center;
  margin-top: 18px;
  padding: 18px 26px;
  color: #04121c;
  background: var(--wb-gradient);
  border: 0;
  border-radius: 10px;
  box-shadow: 0 10px 30px rgba(4, 24, 37, 0.25), 0 0 20px rgba(34, 211, 238, 0.32);
  font-size: 16px;
  font-weight: 800;
  transition: transform 0.2s, box-shadow 0.2s;
}
.cta-section .cta-button:hover {
  transform: translateY(-2px);
  box-shadow: 0 14px 38px rgba(4, 24, 37, 0.3), 0 0 28px rgba(34, 211, 238, 0.45);
  color: #04121c;
}

/* =====================================================================
 * 页脚
 * ===================================================================== */

footer {
  padding: 36px 0;
  background: #03050a;
  color: var(--wb-muted-2);
  font-size: 13px;
}
.footer-row {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 50px;
}
footer strong {
  font-size: 14px;
  color: var(--wb-text);
}
footer p {
  color: var(--wb-muted-2);
  font-size: 12px;
  margin: 8px 0 0;
}
.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 26px;
  font-size: 12px;
}
.copyright {
  grid-column: 1 / -1;
  padding-top: 28px;
  border-top: 1px solid var(--wb-line);
  color: var(--wb-muted-2);
  font-size: 12px;
}

/* =====================================================================
 * 滚动揭示动画（来自 help.js 触发）
 * ===================================================================== */

.motion-ready [data-motion="reveal"] {
  opacity: 0;
  transform: translateY(24px);
  transition:
    opacity var(--motion-reveal-duration) var(--motion-ease-out),
    transform var(--motion-reveal-duration) var(--motion-ease-out);
  transition-delay: var(--motion-delay, 0ms);
}
.motion-ready [data-motion="reveal"].is-visible {
  opacity: 1;
  transform: translateY(0);
}
.motion-ready [data-motion="visual"] {
  opacity: 0;
  transform: translateY(24px) scale(0.98);
  transition:
    opacity var(--motion-reveal-duration) var(--motion-ease-out),
    transform var(--motion-reveal-duration) var(--motion-ease-out);
}
.motion-ready [data-motion="visual"].is-visible {
  opacity: 1;
  transform: translateY(0) scale(1);
}

/* =====================================================================
 * 浅色主题 — 同 workbench 的 .theme-light 契约
 * ===================================================================== */

body.theme-light {
  --wb-bg: #f1f5fa;
  --wb-panel: rgba(255, 255, 255, 0.78);
  --wb-panel-solid: #ffffff;
  --wb-panel-soft: rgba(255, 255, 255, 0.62);
  --wb-line: rgba(18, 55, 110, 0.1);
  --wb-line-strong: rgba(8, 145, 178, 0.38);
  --wb-cyan: #0891b2;
  --wb-sky: #0284c7;
  --wb-indigo: #4f46e5;
  --wb-text: #0d1b2e;
  --wb-muted: #4c5f7a;
  --wb-muted-2: #8496ad;
  --wb-gradient: linear-gradient(135deg, #06b6d4 0%, #3b82f6 50%, #6366f1 100%);
}

body.theme-light::before {
  background-image:
    linear-gradient(rgba(37, 99, 235, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(37, 99, 235, 0.05) 1px, transparent 1px),
    linear-gradient(rgba(37, 99, 235, 0.085) 1px, transparent 1px),
    linear-gradient(90deg, rgba(37, 99, 235, 0.085) 1px, transparent 1px);
}
body.theme-light::after { opacity: 0.42; }

body.theme-light .site-header {
  background: rgba(255, 255, 255, 0.82);
}
body.theme-light .brand-logo-dark { display: none; }
body.theme-light .brand-logo-light { display: block; }
body.theme-light .utility-toggle,
body.theme-light .help-user-button {
  border-color: rgba(18, 55, 110, 0.18);
  background: rgba(13, 30, 55, 0.04);
  color: var(--wb-muted);
}
body.theme-light .help-user-dropdown {
  background: var(--wb-panel-solid);
  border-color: rgba(18, 55, 110, 0.18);
  box-shadow: 0 14px 34px rgba(15, 40, 80, 0.14);
}
body.theme-light .app-link {
  color: var(--wb-cyan);
  background: rgba(8, 145, 178, 0.08);
}
body.theme-light .hero-card {
  background: rgba(255, 255, 255, 0.92);
  border-color: rgba(8, 145, 178, 0.28);
  box-shadow: 0 16px 60px rgba(15, 40, 80, 0.10);
  color: var(--wb-text);
}
body.theme-light .engineering-visual-frame {
  background: var(--wb-panel-solid);
  border-color: rgba(18, 55, 110, 0.18);
  box-shadow: 0 28px 70px rgba(15, 40, 80, 0.14);
}
body.theme-light .hero-card > p { color: var(--wb-muted); }
body.theme-light .format-row { border-color: rgba(18, 55, 110, 0.14); }
body.theme-light .format-row span { color: var(--wb-muted); }
body.theme-light .steps-grid {
  background: rgba(255, 255, 255, 0.92);
}
body.theme-light .step-card { color: var(--wb-text); }
body.theme-light .step-card:hover {
  color: var(--wb-text);
}
body.theme-light .step-card h3 { color: var(--wb-text); }
body.theme-light .step-card:hover h3 { color: var(--wb-text); }
body.theme-light .step-card p { color: var(--wb-muted); }
body.theme-light .step-card:hover p { color: var(--wb-text); }
body.theme-light .split-section,
body.theme-light .faq-section {
  background: rgba(244, 248, 253, 0.65);
}
body.theme-light .privacy-section {
  color: var(--wb-text);
  background-color: var(--wb-bg);
  background-image:
    linear-gradient(rgba(37, 99, 235, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(37, 99, 235, 0.05) 1px, transparent 1px);
}
body.theme-light footer {
  background: #e9f0f7;
}
body.theme-light .privacy-intro > p:last-child,
body.theme-light .data-table span,
body.theme-light .policy-note,
body.theme-light .delete-block ol,
body.theme-light .third-party-grid p,
body.theme-light .security-note p {
  color: var(--wb-muted);
}
body.theme-light .privacy-content > article,
body.theme-light .data-table > div {
  border-color: rgba(18, 55, 110, 0.14);
}
body.theme-light .retention-grid > div,
body.theme-light .third-party-grid > div {
  background: rgba(255, 255, 255, 0.72);
  border-color: rgba(18, 55, 110, 0.14);
}
body.theme-light .delete-block strong { color: var(--wb-text); }
body.theme-light .policy-note { background: rgba(8, 145, 178, 0.06); }

/* =====================================================================
 * 响应式断点
 * ===================================================================== */

@media (max-width: 900px) {
  .site-header {
    height: auto;
    min-height: 76px;
    grid-template-columns: minmax(0, 1fr) auto;
    grid-template-areas:
      "brand actions"
      "nav nav";
    column-gap: 18px;
    row-gap: 0;
    padding-top: 8px;
  }
  .site-header .brand { grid-area: brand; }
  .site-header .nav-links {
    grid-area: nav;
    width: 100%;
    min-width: 0;
    gap: 22px;
    overflow-x: auto;
    padding: 2px 0 9px;
    scrollbar-width: none;
    -webkit-overflow-scrolling: touch;
  }
  .site-header .nav-links::-webkit-scrollbar { display: none; }
  .site-header .nav-links a {
    flex: 0 0 auto;
    padding-block: 7px;
    white-space: nowrap;
  }
  .header-actions { grid-area: actions; }
  .app-link { display: none; }
  .hero { grid-template-columns: 1fr; }
  .hero-card {
    max-width: 520px;
    box-shadow: 0 12px 32px rgba(0, 0, 0, 0.32);
  }
  .steps-grid { grid-template-columns: repeat(2, 1fr); }
  .step-card:nth-child(2) { border-right: 0; }
  .step-card:nth-child(-n + 2) { border-bottom: 1px solid var(--wb-line); }
  .split-grid,
  .privacy-grid,
  .faq-grid {
    grid-template-columns: 1fr;
  }
  .sticky-copy,
  .privacy-intro {
    position: static;
  }
  .retention-grid {
    grid-template-columns: 1fr;
  }
  .retention-grid > div {
    min-height: auto;
  }
}

@media (max-width: 560px) {
  .nav {
    min-height: 66px;
    padding-top: 7px;
    column-gap: 10px;
    row-gap: 0;
  }
  .brand-subtitle { display: none; }
  .brand-name { font-size: 12px; }
  .brand-mark {
    width: 40px;
    height: 40px;
  }
  .header-actions { gap: 5px; }
  .site-header .nav-links { gap: 18px; padding-bottom: 7px; font-size: 12px; }
  .utility-toggle {
    width: 34px;
    height: 34px;
  }
  .utility-toggle.language { width: 46px; }
  .help-user-button {
    min-height: 34px;
    max-width: 88px;
    padding-inline: 9px;
  }
  .hero {
    min-height: 0;
    padding-top: 70px;
    gap: 55px;
  }
  .hero h1 {
    font-size: 39px;
    overflow-wrap: anywhere;
  }
  .system-line {
    max-width: 100%;
    font-size: 9px;
    letter-spacing: 0.06em;
  }
  .hero-actions {
    align-items: flex-start;
    flex-direction: column;
    gap: 22px;
  }
  .engineering-visual { padding-top: 10px; }
  .engineering-visual img {
    aspect-ratio: 4 / 3;
    object-position: 62% center;
  }
  .engineering-visual figcaption {
    grid-template-columns: 1fr;
    gap: 10px;
  }
  .engineering-visual figcaption span {
    align-items: flex-start;
    flex-direction: column;
    gap: 7px;
  }
  .steps-grid { grid-template-columns: 1fr; }
  .step-card {
    min-height: 240px;
    border-right: 0;
    border-bottom: 1px solid var(--wb-line);
  }
  .step-card:last-child { border-bottom: 0; }
  .step-top { margin-bottom: 55px; }
  .data-table > div { grid-template-columns: 1fr; gap: 8px; }
  .delete-block,
  .security-note { grid-template-columns: 1fr; }
  .third-party-grid > div { padding: 20px 17px; }
  footer { grid-template-columns: 1fr; }
  .footer-links { gap: 18px; }
}

@media (max-width: 380px) {
  .brand > span:last-child { display: none; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .system-line span,
  .primary-button::after,
  .retention-grid > div,
  .third-party-grid > div,
  .step-card,
  .step-card::before,
  .utility-toggle,
  .help-user-button {
    transition: none !important;
    animation: none !important;
  }
  .motion-ready [data-motion] {
    transform: none;
    transition: opacity 200ms ease;
    transition-delay: 0ms;
  }
}

/* === Mobile hamburger menu === */
.help-menu-toggle {
  display: none;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  padding: 0;
  border: 1px solid var(--wb-line);
  border-radius: 10px;
  background: rgba(255, 255, 255, 0.04);
  color: var(--wb-text);
  cursor: pointer;
  -webkit-tap-highlight-color: transparent;
  transition: background 0.18s ease, border-color 0.18s ease;
}

.help-menu-toggle:hover,
.help-menu-toggle:focus-visible {
  background: rgba(34, 211, 238, 0.08);
  border-color: var(--wb-line-strong);
  outline: none;
}

.help-menu-toggle-icon {
  position: relative;
  display: block;
  width: 18px;
  height: 14px;
}

.help-menu-toggle-icon span {
  position: absolute;
  left: 0;
  width: 100%;
  height: 2px;
  border-radius: 2px;
  background: currentColor;
  transition: transform 0.22s ease, opacity 0.18s ease, top 0.22s ease;
}

.help-menu-toggle-icon span:nth-child(1) { top: 0; }
.help-menu-toggle-icon span:nth-child(2) { top: 6px; }
.help-menu-toggle-icon span:nth-child(3) { top: 12px; }

.help-menu-open .help-menu-toggle-icon span:nth-child(1) {
  top: 6px;
  transform: rotate(45deg);
}

.help-menu-open .help-menu-toggle-icon span:nth-child(2) {
  opacity: 0;
}

.help-menu-open .help-menu-toggle-icon span:nth-child(3) {
  top: 6px;
  transform: rotate(-45deg);
}

@keyframes help-menu-in {
  from { opacity: 0; transform: translateY(-6px); }
  to   { opacity: 1; transform: translateY(0); }
}

@media (max-width: 900px) {
  .nav {
    grid-template-columns: minmax(0, 1fr) auto;
    grid-template-areas:
      "brand toggle"
      "nav nav"
      "actions actions";
    column-gap: 18px;
    row-gap: 0;
    padding-top: 8px;
  }
  .site-header .brand { grid-area: brand; }
  .help-menu-toggle { grid-area: toggle; display: inline-flex; }
  .site-header .nav-links {
    grid-area: nav;
    width: 100%;
    min-width: 0;
    gap: 6px;
    overflow: visible;
    padding: 0;
    display: none;
    flex-direction: column;
    align-items: stretch;
    margin-top: 8px;
    border: 1px solid var(--wb-line);
    border-radius: 14px;
    background: var(--wb-panel-solid, #0b1220);
    box-shadow: 0 18px 42px rgba(0, 0, 0, 0.55);
    animation: help-menu-in 0.18s ease-out;
  }
  body.theme-light .site-header .nav-links {
    background: #ffffff;
    box-shadow: 0 18px 42px rgba(15, 23, 42, 0.18);
  }
  .site-header.help-menu-open .nav-links { display: flex; }
  .site-header .nav-links::-webkit-scrollbar { display: none; }
  .site-header .nav-links a {
    flex: 0 0 auto;
    display: block;
    padding: 10px 14px;
    border-radius: 10px;
    color: var(--wb-text);
    background: rgba(255, 255, 255, 0.04);
    white-space: normal;
  }
  body.theme-light .site-header .nav-links a {
    background: rgba(15, 23, 42, 0.04);
  }
  .site-header .nav-links a:hover,
  .site-header .nav-links a:focus-visible {
    color: var(--wb-cyan);
    background: rgba(34, 211, 238, 0.1);
  }
  .site-header .nav-links a + a { margin-top: 4px; }

  .header-actions {
    grid-area: actions;
    width: 100%;
    justify-self: stretch;
    justify-content: space-between;
    flex-wrap: wrap;
    margin-top: 8px;
    padding: 10px;
    border: 1px solid var(--wb-line);
    border-radius: 14px;
    background: var(--wb-panel-solid, #0b1220);
    display: none;
    animation: help-menu-in 0.18s ease-out;
  }
  body.theme-light .header-actions {
    background: #ffffff;
  }
  .site-header.help-menu-open .header-actions { display: flex; }
  .site-header.help-menu-open .app-link { display: inline-flex; }
}

@media (min-width: 901px) {
  .site-header.help-menu-open nav,
  .site-header.help-menu-open .header-actions {
    display: flex;
  }
}