/* ============================================================
   Pascal 官网 · 设计系统
   基础框架:Claude Design System v1.1(暖米白 · 杂志排版)
   品牌适配:强调色使用 Pascal 附魔书品牌紫 #7C3AED
   ============================================================ */

:root,
:root[data-theme="light"] {
  /* 基础色板 */
  --color-bg: #faf9f5;
  --color-text: #1a1918;
  --color-body: #55524d;
  --color-muted: #8e8b82;
  --color-accent: #7C3AED;
  --color-border: #e8e4dc;

  /* 语义色板 */
  --accent-light: rgba(124, 58, 237, 0.08);
  --accent-hover: #5B21B6;
  --accent-soft: rgba(124, 58, 237, 0.14);
  --bg-subtle: #f3f0ea;
  --bg-overlay: rgba(250, 249, 245, 0.85);

  /* 字体 */
  --font-serif: "Lora", "Georgia", "Noto Serif SC", "Songti SC", serif;
  --font-sans: "Inter", -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-mono: "JetBrains Mono", "Menlo", monospace;

  /* 间距(8px base) */
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;
  --space-2xl: 48px;
  --space-3xl: 80px;

  --ease: cubic-bezier(0.4, 0, 0.2, 1);
  --content: 680px;
  --wide: 960px;
}

/* ---------- 深色主题（手动切换或跟随系统） ---------- */
:root[data-theme="dark"] {
  --color-bg: #1c1c1a;
  --color-text: #faf9f5;
  --color-body: #b5b2ab;
  --color-muted: #6e6b63;
  --color-border: #2e2c28;
  --bg-subtle: #252522;
  --bg-overlay: rgba(28, 28, 26, 0.85);
  --accent-light: rgba(124, 58, 237, 0.16);
  --accent-soft: rgba(124, 58, 237, 0.22);
  --accent-hover: #A78BFA;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme]) {
    --color-bg: #1c1c1a;
    --color-text: #faf9f5;
    --color-body: #b5b2ab;
    --color-muted: #6e6b63;
    --color-border: #2e2c28;
    --bg-subtle: #252522;
    --bg-overlay: rgba(28, 28, 26, 0.85);
    --accent-light: rgba(124, 58, 237, 0.16);
    --accent-soft: rgba(124, 58, 237, 0.22);
    --accent-hover: #A78BFA;
  }
}

/* ---------- 基础 ---------- */
*, *::before, *::after { box-sizing: border-box; }

html { scroll-behavior: smooth; overflow-x: clip; }
@supports not (overflow-x: clip) {
  html { overflow-x: hidden; }
}

body {
  margin: 0;
  background: var(--color-bg);
  color: var(--color-body);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  transition: background-color 0.3s var(--ease), color 0.3s var(--ease);
}

h1, h2, h3, h4 {
  font-family: var(--font-serif);
  color: var(--color-text);
  font-weight: 500;
  line-height: 1.3;
  margin: 0;
}

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

p { margin: 0; }

img, svg { display: block; max-width: 100%; }

::selection {
  background: var(--accent-soft);
  color: var(--color-text);
}

/* 可访问性:focus 可见 */
a:focus-visible,
button:focus-visible,
summary:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 3px;
  border-radius: 4px;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  padding: 10px 20px;
  background: var(--color-accent);
  color: #faf9f5;
  font-size: 14px;
  z-index: 100;
}
.skip-link:focus { left: 16px; top: 16px; }

/* ---------- 布局容器 ---------- */
.container {
  max-width: var(--content);
  margin: 0 auto;
  padding: 0 24px;
}
.container--wide {
  max-width: var(--wide);
}

/* ============================================================
   顶部导航
   ============================================================ */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: var(--bg-overlay);
  border-bottom: 1px solid var(--color-border);
}

.nav {
  max-width: var(--wide);
  margin: 0 auto;
  padding: 0 24px;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-serif);
  font-size: 19px;
  font-weight: 600;
  color: var(--color-text);
  letter-spacing: 0.01em;
}

.nav-brand .brand-mark {
  width: 22px;
  height: 22px;
  color: var(--color-accent);
  flex: none;
  background-color: var(--color-accent);
  -webkit-mask: url("../logo.svg") center / contain no-repeat;
  mask: url("../logo.svg") center / contain no-repeat;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 28px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-links a {
  font-size: 14px;
  font-weight: 500;
  color: var(--color-body);
  transition: color 0.2s var(--ease);
}

.nav-links a:hover { color: var(--color-accent); }

.nav-links a[aria-current="page"] {
  color: var(--color-accent);
}

.nav-cta {
  font-size: 14px;
  font-weight: 500;
  color: var(--color-accent);
  border: 1px solid var(--accent-soft);
  background: var(--accent-light);
  padding: 7px 18px;
  border-radius: 8px;
  transition: border-color 0.2s var(--ease), color 0.2s var(--ease);
}
.nav-cta:hover { border-color: var(--color-accent); color: var(--accent-hover); }

/* 导航面板：桌面端横向排列（EN 切换 + 链接），移动端 fixed 滑入面板 */
.nav-menu {
  display: flex;
  align-items: center;
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  padding: 8px;
  cursor: pointer;
  color: var(--color-text);
}

.nav-menu-close {
  display: none;
  background: none;
  border: none;
  padding: 8px;
  cursor: pointer;
  color: var(--color-muted);
  position: absolute;
  top: 18px;
  right: 18px;
  border-radius: 8px;
  transition: color 0.2s var(--ease);
}
.nav-menu-close:hover { color: var(--color-accent); }

/* ============================================================
   通用组件
   ============================================================ */

/* 小标签 Label / Tag */
.label {
  display: inline-block;
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--color-muted);
}

.tag {
  display: inline-block;
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-accent);
  background: var(--accent-light);
  padding: 3px 10px;
  border-radius: 6px;
}

/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 14px;
  font-weight: 500;
  color: var(--color-accent);
  background: none;
  border: 1px solid var(--color-border);
  padding: 12px 26px;
  border-radius: 8px;
  cursor: pointer;
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease), background-color 0.2s var(--ease);
  white-space: nowrap;
}
.btn:hover {
  color: var(--accent-hover);
  border-color: var(--color-accent);
}

.btn--primary {
  background: var(--accent-light);
  border-color: var(--accent-soft);
}
.btn--primary:hover {
  background: var(--accent-soft);
  border-color: var(--color-accent);
}

.btn--ghost {
  border-color: transparent;
  padding-left: 0;
  padding-right: 0;
  color: var(--color-body);
  text-decoration: underline;
  text-decoration-color: var(--color-border);
  text-underline-offset: 5px;
}
.btn--ghost:hover {
  color: var(--color-accent);
  text-decoration-color: var(--color-accent);
  border-color: transparent;
}

/* 卡片(妙用圆角 ≤12px,Hover 仅边框颜色变化) */
.card {
  background: var(--bg-subtle);
  border-radius: 12px;
  padding: 32px;
  border: 1px solid transparent;
  transition: border-color 0.25s var(--ease);
}
.card:hover { border-color: var(--color-border); }

/* 列表项(border-top 分割,收尾无下边框) */
.list-item {
  display: block;
  padding: 26px 0;
  border-top: 1px solid var(--color-border);
  position: relative;
}
.list-item:last-child { border-bottom: none; }

.divider {
  border: none;
  border-top: 1px solid var(--color-border);
  margin: 0;
}

/* 区块标题节奏 */
.section-head { margin-bottom: var(--space-2xl); }
.section-head .label { margin-bottom: 12px; }
.section-head h2 {
  font-size: 32px;
  letter-spacing: -0.015em;
  line-height: 1.25;
}
.section-head .lead {
  margin-top: 14px;
  font-size: 17px;
  color: var(--color-body);
  max-width: 560px;
}

section { padding: 96px 0; }

/* ============================================================
   Hero
   ============================================================ */
.hero {
  position: relative;
  padding: 112px 0 96px;
  overflow: hidden;
}

.hero-inner { position: relative; }

.hero .hero-tag {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: var(--space-lg);
}

.hero h1 {
  font-size: 58px;
  font-weight: 500;
  letter-spacing: -0.03em;
  line-height: 1.08;
}

.hero .tagline {
  margin-top: 18px;
  font-size: 22px;
  font-weight: 400;
  color: var(--color-text);
  font-family: var(--font-serif);
  letter-spacing: -0.01em;
}

.hero .tagline-en {
  margin-top: 6px;
  font-size: 15px;
  color: var(--color-muted);
  font-style: italic;
}

.hero .lead {
  margin-top: var(--space-lg);
  font-size: 17px;
  max-width: 560px;
}

.hero .versions {
  margin-top: var(--space-md);
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--color-muted);
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}
.hero .versions .dot {
  width: 3px;
  height: 3px;
  border-radius: 50%;
  background: var(--color-muted);
}

.hero .hero-actions {
  margin-top: var(--space-xl);
  display: flex;
  align-items: center;
  gap: var(--space-lg);
  flex-wrap: wrap;
}

/* ============================================================
   特性卡片区
   ============================================================ */
.features-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-md);
}

@media (min-width: 768px) {
  .features-grid { grid-template-columns: repeat(3, 1fr); }
}

.feature-card {
  padding: 28px;
}
.feature-card .icon {
  width: 20px;
  height: 20px;
  color: var(--color-accent);
  margin-bottom: 18px;
}
.feature-card h3 {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 8px;
  letter-spacing: -0.01em;
}
.feature-card p {
  font-size: 14.5px;
  line-height: 1.65;
  color: var(--color-body);
}

/* ============================================================
   版本对比
   ============================================================ */
.compare-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-md);
}
@media (min-width: 640px) {
  .compare-grid { grid-template-columns: 1fr 1fr; }
}

.compare-card {
  position: relative;
  padding: 36px 32px;
  overflow: hidden;
}
.compare-card .version {
  font-family: var(--font-mono);
  font-size: 34px;
  font-weight: 500;
  color: var(--color-accent);
  letter-spacing: 0.02em;
  line-height: 1.1;
}
.compare-card h3 {
  margin-top: 10px;
  font-size: 22px;
  font-weight: 600;
}
.compare-card p {
  margin-top: 10px;
  font-size: 15px;
  color: var(--color-body);
}

/* ============================================================
   展示区:纯抽象品牌视觉占位(无截图、无渐变、字标浮雕/几何线条)
   ============================================================ */
.showcase-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-md);
}
@media (min-width: 768px) {
  .showcase-grid { grid-template-columns: 1fr 1fr; }
  .showcase-panel--tall { grid-row: span 2; }
}

.showcase-panel {
  border: 1px solid var(--color-border);
  border-radius: 12px;
  background: var(--bg-subtle);
  min-height: 260px;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}
.showcase-panel--tall { min-height: 540px; }

/* 字标浮雕 */
.relief-mark {
  width: 148px;
  aspect-ratio: 1452 / 1728;
  background-color: var(--color-text);
  opacity: 0.14;
  -webkit-mask: url("../logo.svg") center / contain no-repeat;
  mask: url("../logo.svg") center / contain no-repeat;
}

/* 几何线条面板 */
.geo-panel svg { width: 82%; height: 82%; }

/* 像素附魔书放大(保留像素感) */
.pixel-book {
  width: 128px;
  height: 128px;
  image-rendering: pixelated;
}

.showcase-note {
  margin-top: var(--space-lg);
  text-align: center;
  font-size: 13px;
  color: var(--color-muted);
  letter-spacing: 0.04em;
}

/* ============================================================
   步骤(download 动线 / 编号列表)
   ============================================================ */
.steps { counter-reset: step; }

.step {
  display: flex;
  align-items: baseline;
  gap: var(--space-lg);
  padding: 28px 0;
  border-top: 1px solid var(--color-border);
  position: relative;
  transition: background-color 0.25s var(--ease);
}
.step:last-child { border-bottom: none; }
.step::before {
  content: "";
  position: absolute;
  left: -16px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: transparent;
  transition: background 0.25s var(--ease);
}
.step:hover::before { background: var(--color-accent); }

.step .num {
  counter-increment: step;
  font-family: var(--font-mono);
  font-weight: 500;
  font-size: 13px;
  color: var(--color-muted);
  flex: none;
  width: 32px;
  letter-spacing: 0.05em;
}
.step .num::after { content: counter(step, decimal-leading-zero); }

.step-body { flex: 1; min-width: 0; }
.step-body h3 {
  font-size: 19px;
  font-weight: 600;
  font-family: var(--font-sans);
  letter-spacing: -0.01em;
  color: var(--color-text);
  transition: color 0.2s var(--ease);
}
.step-body h3 .arrow {
  display: inline-block;
  margin-left: 6px;
  color: var(--color-muted);
  font-weight: 400;
  transition: color 0.2s var(--ease);
}
a.step:hover .step-body h3 { color: var(--color-accent); }
a.step:hover .step-body h3 .arrow { color: var(--color-accent); }
.step-body p {
  margin-top: 6px;
  font-size: 15px;
  color: var(--color-body);
}

/* ============================================================
   FAQ(details/summary,无 JS)
   ============================================================ */
.faq-item {
  border-top: 1px solid var(--color-border);
  position: relative;
  scroll-margin-top: 88px;
}
.faq-item:last-child { border-bottom: none; }

.faq-item summary {
  list-style: none;
  cursor: pointer;
  padding: 26px 0;
  display: flex;
  align-items: baseline;
  gap: var(--space-md);
  justify-content: space-between;
  transition: color 0.2s var(--ease);
}
.faq-item summary::-webkit-details-marker { display: none; }

.faq-item summary .q {
  font-family: var(--font-sans);
  font-size: 17px;
  font-weight: 600;
  color: var(--color-text);
  letter-spacing: -0.01em;
  flex: 1;
}
.faq-item summary:hover .q { color: var(--color-accent); }

.faq-item summary .indicator {
  flex: none;
  width: 16px;
  height: 16px;
  color: var(--color-muted);
  transition: color 0.2s var(--ease), transform 0.25s var(--ease);
}
.faq-item[open] summary .indicator {
  transform: rotate(90deg);
  color: var(--color-accent);
}

.faq-item .a {
  padding: 0 0 28px;
  max-width: 560px;
  font-size: 15.5px;
}
.faq-item .a p + p { margin-top: 10px; }
.faq-item .a a {
  color: var(--color-accent);
  text-decoration: underline;
  text-decoration-color: var(--accent-soft);
  text-underline-offset: 4px;
  transition: text-decoration-color 0.2s var(--ease);
}
.faq-item .a a:hover { text-decoration-color: var(--color-accent); }

/* ============================================================
   CTA 带状区
   ============================================================ */
.cta-band {
  text-align: center;
  padding-top: 24px;
}
.cta-band h2 {
  font-size: 34px;
  letter-spacing: -0.02em;
}
.cta-band p {
  margin: 14px auto 0;
  max-width: 480px;
  font-size: 16px;
}
.cta-band .hero-actions {
  margin-top: var(--space-xl);
  display: flex;
  gap: var(--space-lg);
  justify-content: center;
  flex-wrap: wrap;
}

/* ============================================================
   页脚
   ============================================================ */
.site-footer {
  border-top: 1px solid var(--color-border);
  padding: 56px 0 40px;
  margin-top: 48px;
}

.footer-grid {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2xl);
  justify-content: space-between;
}

.footer-brand { max-width: 320px; }
.footer-brand .nav-brand { margin-bottom: 14px; }
.footer-brand p { font-size: 14px; color: var(--color-muted); }

.footer-col h4 {
  font-family: var(--font-sans);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-muted);
  margin-bottom: 14px;
}
.footer-col ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 10px;
}
.footer-col a {
  font-size: 14px;
  color: var(--color-body);
  transition: color 0.2s var(--ease);
}
.footer-col a:hover { color: var(--color-accent); }

.footer-legal {
  margin-top: var(--space-2xl);
  padding-top: var(--space-xl);
  border-top: 1px solid var(--color-border);
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md);
  justify-content: space-between;
  font-size: 13px;
  color: var(--color-muted);
}

/* ============================================================
   页面内首屏(子页面 H1)
   ============================================================ */
.page-hero {
  padding: 88px 0 56px;
}
.page-hero .tag-row {
  margin-bottom: var(--space-md);
}
.page-hero h1 {
  font-size: 44px;
  letter-spacing: -0.025em;
  line-height: 1.15;
}
.page-hero .subtitle {
  margin-top: 8px;
  font-size: 15px;
  font-style: italic;
  color: var(--color-muted);
}
.page-hero .lead {
  margin-top: var(--space-lg);
  font-size: 17px;
  max-width: 560px;
}

/* ============================================================
   响应式
   ============================================================ */
@media (max-width: 640px) {
  body { font-size: 15.5px; }
  .container { padding: 0 24px; }
  section { padding: 72px 0; }

  .hero { padding: 72px 0 64px; }
  .hero h1 { font-size: 42px; }
  .hero .tagline { font-size: 19px; }

  .page-hero { padding: 64px 0 40px; }
  .page-hero h1 { font-size: 34px; }

  .section-head h2 { font-size: 27px; }
  .cta-band h2 { font-size: 28px; }

  .card, .compare-card { padding: 26px; }
  .feature-card { padding: 24px; }

  .showcase-panel--tall { min-height: 320px; }

  /* 移动导航：Polar 式右侧滑入面板（出场动效 0.5s） */
  .nav-toggle { display: inline-flex; }
  .nav-menu {
    position: fixed;
    top: 0;
    right: 0;
    height: 100vh;
    width: 300px;
    max-width: 85vw;
    background: var(--color-bg);
    border-left: 1px solid var(--color-border);
    box-shadow: -12px 0 32px rgba(0, 0, 0, .08);
    padding: 88px 28px 32px;
    display: flex;
    flex-direction: column;
    align-items: stretch;
    transform: translateX(105%);
    visibility: hidden;
    transition: transform 0.5s var(--ease), visibility 0.5s;
    z-index: 70;
  }
  .nav-menu[data-open="true"] {
    transform: translateX(0);
    visibility: visible;
  }
  .nav-menu-close { display: inline-flex; }
  body.no-scroll { overflow: hidden; }
  .nav-links {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    margin: 0;
  }
  .nav-links a {
    font-size: 16px;
    padding: 14px 0;
    display: block;
    border-bottom: 1px solid var(--color-border);
  }
  .nav-cta { display: block; margin-top: 18px; text-align: center; }

  .footer-grid { gap: var(--space-xl); }
}

/* 动效偏好:减少动画 */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}

/* ============================================================
   Polar Hero（首屏保留 Polar 设计 · 已移除全部光效）
   深色首屏带 + 启动器 + 标题 + 按钮；以下内容为 Fixed 暖米白风格
   ============================================================ */
.polar-hero {
  background: linear-gradient(180deg, rgba(18, 18, 24, .72), rgba(18, 18, 24, .85));
  background-attachment: fixed;
  color: #fff;
  padding: 88px 0 160px;
  position: relative;
  overflow: hidden;
  /* 填满用户屏幕（检测视口高度，非全屏） */
  min-height: 100vh;
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
  justify-content: center;
}
/* 壁纸背景版隐藏左右波纹 */
.polar-hero::before,
.polar-hero::after { display: none; }
.hero-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}
.hero-wrapper {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 40px;
  position: relative;
  z-index: 1;
}
.hero-wrapper__offer {
  flex: 0 1 540px;
  min-width: 0;
  max-width: 540px;
}
.hero-wrapper__img {
  flex: 0 0 560px;
  position: relative;
}
.hero-title {
  font-family: 'Montserrat', sans-serif;
  font-weight: 800;
  font-size: clamp(32px, 3.8vw, 44px);
  line-height: 1.35;
  letter-spacing: .01em;
  color: #fff;
  max-width: 560px;
  margin-bottom: 20px;
}
.hero-title > .hero-title__blue {
  color: #A78BFA;
  background-image: url("data:image/svg+xml,%3Csvg%20xmlns='http://www.w3.org/2000/svg'%20viewBox='0%200%2060%2010'%20preserveAspectRatio='none'%3E%0A%3Cpath%20d='M0%206%20C%2012%203.5,%2024%208,%2036%206%20C%2046%204.5,%2054%207,%2060%205.8'%20fill='none'%20stroke='%23A78BFA'%20stroke-width='2'%20stroke-linecap='round'%20stroke-linejoin='round'/%3E%0A%3C/svg%3E");
  background-repeat: repeat-x;
  background-position: 0 calc(100% - 1px);
  background-size: 60px 10px;
  padding-bottom: 8px;
}
.hero-description {
  font-size: 16px;
  line-height: 1.8;
  color: rgba(255, 255, 255, .68);
  max-width: 540px;
  margin-bottom: 22px;
}
.hero-description a {
  color: #A78BFA;
  text-decoration: underline;
  text-underline-offset: 3px;
}
.hero-btns {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
}
.hero-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  font-weight: 500;
  color: #A78BFA;
  background: rgba(167, 139, 250, 0.1);
  border: 1px solid rgba(167, 139, 250, 0.4);
  border-radius: 8px;
  padding: 13px 28px;
  white-space: nowrap;
  transition: border-color .2s var(--ease), color .2s var(--ease), background-color .2s var(--ease);
}
.hero-btn:hover {
  color: #fff;
  border-color: #A78BFA;
  background: rgba(167, 139, 250, 0.18);
}
.hero-btn--dark {
  color: rgba(255, 255, 255, .75);
  background: transparent;
  border-color: rgba(255, 255, 255, .28);
}
.hero-btn--dark:hover {
  color: #fff;
  border-color: rgba(255, 255, 255, .6);
  background: rgba(255, 255, 255, .06);
}
.hero-launcher {
  width: 560px;
  height: 400px;
  border: 1px solid rgba(167, 139, 250, .45);
  border-radius: 14px;
  background:
    linear-gradient(160deg, rgba(124, 58, 237, .22), rgba(46, 16, 101, .16)),
    repeating-linear-gradient(45deg, rgba(255, 255, 255, .03) 0 2px, transparent 2px 6px);
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
  transform: perspective(1100px) rotateY(-18deg) rotateX(4deg);
  -webkit-transform: perspective(1100px) rotateY(-18deg) rotateX(4deg);
  transform-origin: 50% 50%;
  box-shadow: 0 24px 48px rgba(0, 0, 0, .35);
}
.hero-launcher img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  display: block;
}
/* 左右不对称波纹装饰（保留 Polar 设计组件，无光效） */
.polar-hero::before {
  content: "";
  width: 565px;
  height: 557px;
  background: url("../img/elements/header_left.svg") no-repeat center center/contain;
  position: absolute;
  left: -393px;
  top: 50%;
  transform: translateY(-50%);
  -webkit-transform: translateY(-50%);
  z-index: 0;
  pointer-events: none;
}
.polar-hero::after {
  content: "";
  width: 480px;
  height: 550px;
  background: url("../img/elements/header_right.svg") no-repeat center center/contain;
  position: absolute;
  right: -200px;
  top: 50%;
  transform: translateY(-50%);
  -webkit-transform: translateY(-50%);
  z-index: 0;
  pointer-events: none;
}

/* 响应式 */
@media (max-width: 1024px) {
  .hero-wrapper {
    flex-direction: column;
    align-items: center;
    text-align: center;
  }
  .hero-wrapper__img { display: block; }
  .hero-wrapper__offer { flex: 1 1 auto; max-width: 100%; }
  .hero-launcher {
    width: 100%;
    max-width: 420px;
    height: auto;
    aspect-ratio: 728 / 528;
    margin: 28px auto 0;
  }
  .hero-btns { justify-content: center; }
}
@media (max-width: 640px) {
  .polar-hero { padding: 64px 0 96px; }
  .hero-title { font-size: 32px; }
  .hero-btns { flex-direction: column; }
  .hero-btn { width: 100%; }
}
@media (max-width: 575px) {
  .polar-hero::before { width: 160px; height: 160px; left: -110px; }
  .polar-hero::after { width: 100px; height: 100px; right: -70px; }
}

/* ============================================================
   子页首屏（独立布局 · 不照搬首页 Hero）
   左文案 + 右入口卡的分栏式 intro
   ============================================================ */
.page-intro {
  padding: 88px 0 72px;
  border-bottom: 1px solid var(--color-border);
  background: linear-gradient(180deg, var(--bg-subtle), var(--color-bg));
}
.page-intro__grid {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
  gap: 56px;
  align-items: center;
}
.page-intro__main .tag { margin-bottom: 18px; }
.page-intro__main h1 {
  font-size: clamp(40px, 4.6vw, 56px);
  letter-spacing: -0.03em;
  line-height: 1.08;
  margin-bottom: 20px;
}
.page-intro__main .lead {
  font-size: 17px;
  line-height: 1.75;
  color: var(--color-body);
  max-width: 480px;
  margin-bottom: 30px;
}
.page-intro__main .lead a {
  color: var(--color-accent);
  text-decoration: underline;
  text-underline-offset: 4px;
}
.intro-actions {
  display: flex;
  align-items: center;
  gap: 14px;
  flex-wrap: wrap;
}
.intro-cards {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}
.intro-card {
  display: block;
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: 12px;
  padding: 20px;
  transition: border-color .25s var(--ease), transform .25s var(--ease);
}
.intro-card:hover {
  border-color: var(--color-accent);
  transform: translateY(-2px);
}
.intro-card .num {
  font-family: var(--font-mono);
  font-weight: 500;
  font-size: 13px;
  letter-spacing: .05em;
  color: var(--color-accent);
}
.intro-card .arrow {
  font-size: 14px;
  color: var(--color-muted);
  transition: color .2s var(--ease), transform .2s var(--ease);
  display: inline-block;
}
.intro-card:hover .arrow { color: var(--color-accent); transform: translateX(3px); }
.intro-card h3 {
  font-family: var(--font-sans);
  font-size: 16px;
  font-weight: 600;
  color: var(--color-text);
  letter-spacing: -0.01em;
  margin: 10px 0 6px;
}
.intro-card p {
  font-size: 13.5px;
  line-height: 1.6;
  color: var(--color-body);
  margin: 0;
}

@media (max-width: 860px) {
  .page-intro { padding: 64px 0 56px; }
  .page-intro__grid { grid-template-columns: 1fr; gap: 36px; }
  .page-intro__main h1 { font-size: 40px; }
}
@media (max-width: 480px) {
  .intro-cards { grid-template-columns: 1fr; }
  .intro-actions { flex-direction: column; align-items: stretch; }
  .intro-actions .btn { justify-content: center; }
}

/* ============================================================
   语言切换 · download 翻转 · docs 居中
   ============================================================ */
.lang-toggle {
  background: none;
  border: 1px solid var(--color-border);
  border-radius: 6px;
  font-family: var(--font-sans);
  font-size: 12px;
  font-weight: 500;
  color: var(--color-body);
  padding: 5px 10px;
  cursor: pointer;
  line-height: 1.4;
  transition: border-color .2s var(--ease), color .2s var(--ease);
}
.lang-toggle:hover { border-color: var(--color-accent); color: var(--color-accent); }
.nav-menu .lang-toggle { margin-right: 24px; }
@media (max-width: 640px) {
  .nav-menu .lang-toggle {
    align-self: stretch;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    margin: 0 0 26px;
    border-radius: 8px;
    padding: 14px;
    font-size: 15px;
    text-align: center;
    border-color: var(--color-border);
    color: var(--color-body);
  }
}

/* download：左图右文翻转（Hero 同款图片展示 · 3D 倾斜镜像） */
.page-intro__grid--flip .page-intro__side { order: -1; }
.page-intro__grid--flip .page-intro__side .hero-launcher {
  margin: 0;
  width: 100%;
  max-width: 560px;
  transform: perspective(1100px) rotateY(18deg) rotateX(4deg);
  -webkit-transform: perspective(1100px) rotateY(18deg) rotateX(4deg);
}
@media (max-width: 860px) {
  .page-intro__grid--flip .page-intro__side .hero-launcher {
    max-width: 420px;
  }
}
@media (max-width: 480px) {
  .page-intro__grid--flip .page-intro__side .hero-launcher {
    width: 100%;
    height: auto;
    aspect-ratio: 7 / 5;
    max-width: none;
  }
}

/* docs：居中布局 */
.page-intro--center { text-align: center; }
.page-intro--center .page-intro__grid { grid-template-columns: 1fr; gap: 44px; }
.page-intro--center .page-intro__main { max-width: 680px; margin: 0 auto; }
.page-intro--center .page-intro__main .lead { margin-left: auto; margin-right: auto; }
.page-intro--center .intro-actions { justify-content: center; }
.page-intro--center .intro-cards { max-width: 680px; margin: 0 auto; }

/* ============================================================
   子页首屏壁纸背景（download / docs）
   ============================================================ */
.page-intro--wallpaper {
  background: linear-gradient(180deg, rgba(18, 18, 24, .76), rgba(18, 18, 24, .88));
  background-attachment: fixed;
  border-bottom: none;
  color: #fff;
  /* 填满用户屏幕（同首页 hero） */
  min-height: 100vh;
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.page-intro--wallpaper h1 { color: #fff; }
.page-intro--wallpaper .lead { color: rgba(255, 255, 255, .8); }
.page-intro--wallpaper .tag {
  color: #A78BFA;
  background: rgba(167, 139, 250, .16);
}
.page-intro--wallpaper .btn {
  color: #fff;
  border-color: rgba(255, 255, 255, .42);
}
.page-intro--wallpaper .btn:hover {
  color: #A78BFA;
  border-color: #A78BFA;
}
.page-intro--wallpaper .btn--primary {
  background: rgba(167, 139, 250, .16);
  border-color: rgba(167, 139, 250, .45);
}
.page-intro--wallpaper .btn--primary:hover {
  color: #fff;
  border-color: #A78BFA;
  background: rgba(167, 139, 250, .24);
}

/* ============================================================
   仍需帮助？（docs 底部 CTA · 壁纸固定背景）
   ============================================================ */
.help-cta {
  text-align: center;
  padding: 130px 0;
  /* 覆盖 page-intro--wallpaper 的填满视口规则（本区块只作底部 CTA 带） */
  min-height: auto;
  display: block;
}
.help-cta .tag { margin-bottom: 22px; }
.help-cta h2 {
  font-family: var(--font-serif);
  font-weight: 500;
  font-size: clamp(30px, 3.4vw, 42px);
  letter-spacing: -0.02em;
  line-height: 1.2;
  color: #fff;
  margin: 0 0 16px;
}
.help-cta p {
  font-size: 16px;
  line-height: 1.8;
  color: rgba(255, 255, 255, .8);
  max-width: 480px;
  margin: 0 auto 34px;
}
.help-cta .intro-actions { justify-content: center; }
.help-cta .btn {
  padding: 13px 34px;
  font-size: 15px;
}
@media (max-width: 640px) {
  .help-cta { padding: 88px 0; }
}

/* ============================================================
   展览区胜利截图 · download 宽幅展示图
   ============================================================ */
.showcase-grid--shot {
  grid-template-columns: 1fr;
  max-width: 1100px;
  margin: 0 auto;
}
.showcase-panel--shot {
  min-height: 0;
  display: block;
  background: var(--color-bg);
  padding: 12px;
  border-radius: 14px;
}
.showcase-panel--shot img {
  width: 100%;
  height: auto;
  display: block;
  border-radius: 10px;
}
.showcase-panel[hidden] { display: none; }

/* download 首屏：宽幅展示图（16:7） */
.page-intro__grid--flip .page-intro__side .hero-launcher {
  height: auto;
  aspect-ratio: 1920 / 1018;
}

/* ============================================================
   首页 CTA 壁纸带（同 download/docs Hero 设计）
   ============================================================ */
.cta-band--wallpaper {
  background: linear-gradient(180deg, rgba(18, 18, 24, .78), rgba(18, 18, 24, .9));
  background-attachment: fixed;
  padding: 130px 0;
  border-top: 1px solid rgba(255, 255, 255, .08);
  border-bottom: 1px solid rgba(255, 255, 255, .08);
}

.cta-band--wallpaper .label {
  display: inline-block;
  color: #A78BFA;
  margin-bottom: 16px;
}
.cta-band--wallpaper h2 {
  font-family: var(--font-serif);
  font-weight: 500;
  font-size: clamp(30px, 3.4vw, 42px);
  letter-spacing: -0.02em;
  line-height: 1.2;
  color: #fff;
  margin: 0 0 14px;
}
.cta-band--wallpaper p {
  font-size: 16px;
  line-height: 1.8;
  color: rgba(255, 255, 255, .8);
  max-width: 480px;
  margin: 0 auto 32px;
}
.cta-band--wallpaper .hero-actions { justify-content: center; }
.cta-band--wallpaper .btn {
  padding: 13px 34px;
  font-size: 15px;
  color: #fff;
  border-color: rgba(255, 255, 255, .42);
}
.cta-band--wallpaper .btn:hover {
  color: #A78BFA;
  border-color: #A78BFA;
}
.cta-band--wallpaper .btn--primary {
  background: rgba(167, 139, 250, .16);
  border-color: rgba(167, 139, 250, .45);
}
.cta-band--wallpaper .btn--primary:hover {
  color: #fff;
  border-color: #A78BFA;
  background: rgba(167, 139, 250, .24);
}
@media (max-width: 640px) {
  .cta-band--wallpaper { padding: 88px 0; }
}

/* ============================================================
   版本切换器（switcher）
   ============================================================ */
.version-switcher {
  max-width: 680px;
  margin: 0 auto;
}
.version-switcher__tabs {
  display: flex;
  gap: 4px;
  width: fit-content;
  margin: 0 auto 28px;
  background: var(--bg-subtle);
  border: 1px solid var(--color-border);
  border-radius: 12px;
  padding: 4px;
  position: relative;
}
.version-switcher__thumb {
  position: absolute;
  top: 4px;
  left: 4px;
  height: calc(100% - 8px);
  background: var(--color-accent);
  border-radius: 9px;
  z-index: 0;
  transition: transform .45s cubic-bezier(.16, 1, .3, 1), width .45s cubic-bezier(.16, 1, .3, 1);
}
.version-switcher__tab {
  flex: 1;
  min-width: 108px;
  border: none;
  background: none;
  font-family: var(--font-mono);
  font-weight: 500;
  font-size: 15px;
  color: var(--color-muted);
  padding: 10px 24px;
  border-radius: 9px;
  cursor: pointer;
  position: relative;
  z-index: 1;
  transition: color .25s var(--ease);
}
.version-switcher__tab:hover { color: var(--color-text); }
.version-switcher__tab.is-active {
  color: #fff;
}
.version-switcher__stack {
  display: grid;
  perspective: 1400px;
}
.version-switcher__panel {
  grid-area: 1 / 1;
  background: var(--bg-subtle);
  border: 1px solid var(--color-border);
  border-radius: 14px;
  padding: 44px 36px;
  text-align: center;
  backface-visibility: hidden;
  transform-origin: 50% 50% -90px;
  transform: rotateY(58deg) translateY(28px) scale(.9);
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transition:
    transform .65s cubic-bezier(.16, 1, .3, 1),
    opacity .45s ease,
    visibility 0s linear .65s;
}
.version-switcher__panel.is-active {
  transform: rotateY(0deg) translateY(0) scale(1);
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
  transition:
    transform .65s cubic-bezier(.16, 1, .3, 1),
    opacity .45s ease,
    visibility 0s;
}
.version-switcher__panel .version {
  font-family: var(--font-mono);
  font-weight: 500;
  font-size: 42px;
  letter-spacing: .02em;
  line-height: 1.1;
  color: var(--color-accent);
}
.version-switcher__panel h3 {
  font-family: var(--font-sans);
  font-size: 20px;
  font-weight: 600;
  letter-spacing: -0.01em;
  color: var(--color-text);
  margin: 14px 0 8px;
}
.version-switcher__panel p {
  font-size: 15px;
  line-height: 1.7;
  color: var(--color-body);
  max-width: 420px;
  margin: 0 auto;
}
@media (max-width: 480px) {
  .version-switcher__tab { min-width: 0; flex: 1; padding: 10px 16px; }
  .version-switcher__panel { padding: 32px 22px; }
  .version-switcher__panel .version { font-size: 34px; }
}

/* ============================================================
   download 分发说明（壁纸背景 · 同 Hero 效果）
   ============================================================ */
.notice-wallpaper {
  background: linear-gradient(180deg, rgba(18, 18, 24, .8), rgba(18, 18, 24, .92));
  background-attachment: fixed;
  padding: 96px 0;
  border-top: 1px solid rgba(255, 255, 255, .08);
  border-bottom: 1px solid rgba(255, 255, 255, .08);
  text-align: center;
}
.notice-wallpaper h3 {
  font-family: var(--font-serif);
  font-weight: 500;
  font-size: clamp(24px, 2.6vw, 32px);
  letter-spacing: -0.02em;
  color: #fff;
  margin: 0 0 14px;
}
.notice-wallpaper p {
  font-size: 15px;
  line-height: 1.9;
  color: rgba(255, 255, 255, .8);
  max-width: 560px;
  margin: 0 auto;
}
@media (max-width: 640px) {
  .notice-wallpaper { padding: 72px 0; }
}

/* ============================================================
   主题切换按钮
   ============================================================ */
.theme-toggle {
  background: none;
  border: 1px solid var(--color-border);
  border-radius: 6px;
  width: 32px;
  height: 32px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: var(--color-body);
  cursor: pointer;
  flex: none;
  transition: border-color .2s var(--ease), color .2s var(--ease);
}
.theme-toggle:hover { border-color: var(--color-accent); color: var(--color-accent); }
.nav-menu .theme-toggle { margin-right: 10px; }
@media (max-width: 640px) {
  .nav-menu .theme-toggle { margin: 0 0 26px; align-self: stretch; width: auto; }
}

/* ============================================================
   导航控制组（主题 + 语言）
   ============================================================ */
.nav-controls {
  display: flex;
  align-items: center;
}
.nav-menu .nav-controls .theme-toggle { margin-right: 10px; }
.nav-menu .lang-toggle { margin-right: 0; }
@media (max-width: 640px) {
  .nav-controls {
    width: 100%;
    gap: 10px;
    margin: 0 0 26px;
  }
  .nav-controls .theme-toggle,
  .nav-controls .lang-toggle {
    flex: 1;
    margin: 0;
    width: auto;
    align-self: stretch;
  }
  .nav-controls .lang-toggle {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    text-align: center;
  }
  .nav-menu .lang-toggle { margin-right: 0; }
}

/* ============================================================
   锁滚动（移动端菜单打开）：body 固定 + header 钉视口顶
   ============================================================ */
html.no-scroll { overflow: hidden; }

/* ============================================================
   桌面端：主题/语言恢复独立排布（不打包并排组）
   ============================================================ */
@media (min-width: 641px) {
  .nav-controls { display: contents; }
  .nav-menu .nav-controls .theme-toggle { margin-right: 10px; }
  .nav-menu .lang-toggle { margin-right: 24px; }
}

/* 移动端：主题/语言按钮统一高度 */
@media (max-width: 640px) {
  .nav-controls .theme-toggle,
  .nav-controls .lang-toggle {
    height: 46px;
    box-sizing: border-box;
  }
  .nav-controls .lang-toggle { padding: 0 14px; }
}

/* ============================================================
   首页 header 深色融入 hero（顶部无白条）
   ============================================================ */
.home-page .site-header {
  background: rgba(20, 20, 26, .45);
  border-bottom-color: rgba(255, 255, 255, .08);
}
/* 移动端：header 可见元素（brand/汉堡）白字；面板内链接保持原色（浅底深字） */
.home-page .site-header .nav-brand { color: #fff; }
.home-page .site-header .nav-toggle { color: #fff; }
/* 桌面：深色 header 上全部白字 */
@media (min-width: 641px) {
  .home-page .site-header .nav-links a { color: rgba(255, 255, 255, .78); }
  .home-page .site-header .nav-links a:hover { color: #fff; }
  .home-page .site-header .nav-links a[aria-current="page"] { color: #A78BFA; }
  .home-page .site-header .nav-cta {
    color: #fff;
    border-color: rgba(255, 255, 255, .35);
    background: rgba(255, 255, 255, .08);
  }
  .home-page .site-header .nav-cta:hover { border-color: #fff; color: #fff; }
  .home-page .site-header .lang-toggle,
  .home-page .site-header .theme-toggle {
    color: rgba(255, 255, 255, .78);
    border-color: rgba(255, 255, 255, .3);
  }
  .home-page .site-header .lang-toggle:hover,
  .home-page .site-header .theme-toggle:hover { color: #fff; border-color: #fff; }
}