/* 用途：中文站五页共用的阅读、品牌与交互契约；最后加载，页面样式只保留专属版式。 */
:root {
  --bg: #f5f7f1;
  --surface: #ffffff;
  --surface-soft: #eaf0e6;
  --lime: #d8ef73;
  --fg: #156b57;
  --fg-2: #2f5d4e;
  --muted: #2f5d4e;
  --border: #c6d9ce;
  --accent: #c95b32;
  --font-display: "PingFang SC", "Microsoft YaHei", -apple-system, system-ui, sans-serif;
  --font-body: "PingFang SC", "Microsoft YaHei", -apple-system, system-ui, sans-serif;
  --font-latin: "Helvetica Neue", Helvetica, Arial, sans-serif;
  --font-name: var(--font-latin);
  --container-max: 1180px;
  --motion-fast: 160ms;
  --ui-section-space: 72px;
}

/* 基础阅读：正文、标题字重和辅助字号由同一处定义，保留各页标题尺寸。 */
* { box-sizing: border-box; }
html { color-scheme: light; scroll-behavior: smooth; scroll-padding-top: 24px; }
body.readable-page { margin: 0; background: var(--bg); color: var(--fg); font: 400 24px/1.9 var(--font-body); -webkit-font-smoothing: antialiased; }
:where(body.readable-page) :where(h1, h2, h3, p, figure) { margin: 0; }
body.readable-page :is(h1, h2, h3) { font-family: var(--font-display); font-weight: 700; text-wrap: balance; }
body.readable-page p { font-size: 24px; line-height: 1.9; text-wrap: pretty; }
body.readable-page strong { font-weight: 700; }
body.readable-page :is(.eyebrow, .small-label) { color: var(--fg-2); font-size: 20px; font-weight: 600; line-height: 1.9; letter-spacing: 0; }
body.readable-page :is(.detail-note, .signature-note, .contact-hint, .copy-status, figcaption, .hero-experience) { font-size: 20px; line-height: 1.9; }
body.readable-page .ai-identity > span:last-child { font-size: 20px; font-weight: 600; line-height: 1.9; }
body.readable-page :is(.questions dt, .questions dd) { font-size: 24px; line-height: 1.9; }
body.readable-page img { display: block; max-width: 100%; height: auto; }
body.readable-page :is(.wrap, .container) { width: min(calc(100% - 96px), var(--container-max)); margin-inline: auto; }
body.readable-page :is(.section-space, .section-pad, .fde-section) { padding-block: var(--ui-section-space); }
body.readable-page .section-white { background: var(--surface); }
body.readable-page :is(.hero, .section-grid, .detail-grid, .contact-layout, .ai-hero-layout, .case-row) > * { min-width: 0; }
body.readable-page :is(section[id], figure[id]) { scroll-margin-top: 28px; }

/* 五页共用页眉，原生链接允许自然换行，品牌点延续详情页的橙色。 */
body.readable-page .site-header { min-height: 88px; display: flex; justify-content: space-between; align-items: center; gap: 12px 24px; border-bottom: 1px solid var(--border); }
body.readable-page .wordmark { display: inline-flex; align-items: center; min-height: 52px; font: 800 36px/1 var(--font-latin); letter-spacing: -.05em; }
body.readable-page .wordmark span { color: var(--accent); }
body.readable-page .site-nav { display: flex; flex-wrap: wrap; align-items: center; gap: 4px 30px; min-width: 0; }
body.readable-page .site-nav a { display: inline-flex; align-items: center; gap: 6px; min-height: 52px; max-width: 100%; font-size: 20px; font-weight: 600; line-height: 1.8; }
body.readable-page .international-link { margin-left: 0; }

/* 交互角色：主按钮与普通链接共享字号、字重、点按尺寸和焦点样式。 */
body.readable-page a { color: inherit; font-size: 22px; text-decoration: none; text-underline-offset: 5px; }
body.readable-page button { font: inherit; cursor: pointer; }
body.readable-page :is(a, button) { -webkit-tap-highlight-color: transparent; transition: color var(--motion-fast), background-color var(--motion-fast), transform var(--motion-fast); }
body.readable-page :is(a, button):focus-visible { outline: 3px solid var(--accent); outline-offset: 5px; }
body.readable-page :is(.button, .btn) { display: inline-flex; align-items: center; justify-content: center; gap: 22px; min-height: 60px; max-width: 100%; padding: 14px 24px; border: 1px solid var(--fg); border-radius: 8px; background: var(--fg); color: var(--surface); font-size: 22px; font-weight: 600; line-height: 1.6; letter-spacing: .02em; }
body.readable-page :is(.button, .btn):hover { background: var(--fg-2); }
body.readable-page :is(.button, .btn, .copy-button):disabled { opacity: .65; cursor: default; transform: none; }
body.readable-page :is(.text-link, .back-link, .fde-link, .detail-related a) { align-items: center; flex-wrap: wrap; gap: 8px 14px; min-height: 52px; max-width: 100%; font-size: 22px; font-weight: 600; line-height: 1.8; text-decoration: underline; text-decoration-color: var(--border); }
:where(body.readable-page) :is(.text-link, .back-link, .fde-link) { display: inline-flex; }
body.readable-page :is(.text-link, .back-link, .fde-link, .detail-related a):hover { text-decoration-color: var(--fg); }
body.readable-page :is(.text-link, .back-link, .fde-link) span { flex: 0 0 auto; }
body.readable-page :is(.site-nav a, .site-footer a):hover { text-decoration: underline; }
body.readable-page .skip-link { position: absolute; top: -100px; left: 20px; z-index: 10; min-height: 52px; padding: 12px 18px; background: var(--lime); border: 1px solid var(--fg); font-size: 20px; }
body.readable-page .skip-link:focus { top: 12px; }
body.readable-page ::selection { color: var(--fg); background: var(--lime); }

/* 联系区复用原始二维码和邮箱回退，五页只维护一套尺寸及操作样式。 */
body.readable-page .contact { background: var(--lime); }
/* 联系文案使用余下宽度，二维码列与原始面板同宽，左右外缘与整页容器对齐。 */
body.readable-page .contact-layout { display: grid; grid-template-columns: minmax(0, 1fr) 280px; gap: 48px; align-items: start; }
body.readable-page .email-alternative { display: flex; flex-wrap: wrap; align-items: center; gap: 6px 16px; margin-top: 28px; padding-top: 20px; border-top: 1px solid var(--fg); }
body.readable-page .email-alternative > :is(.contact-hint, .small-label) { flex-basis: 100%; }
body.readable-page .email-link { display: inline-flex; align-items: center; flex-wrap: wrap; gap: 10px; max-width: 100%; min-height: 52px; font-size: 24px; font-weight: 400; line-height: 1.8; }
body.readable-page .email-link:hover { text-decoration: underline; }
body.readable-page :is(.contact-value, .email-link [data-contact-value]) { min-width: 0; overflow-wrap: anywhere; user-select: all; -webkit-user-select: all; }
body.readable-page .copy-button { display: inline-flex; align-items: center; min-height: 52px; padding: 8px 12px; border: 0; background: transparent; color: var(--fg); font-size: 20px; font-weight: 600; line-height: 1.8; text-decoration: underline; text-underline-offset: 5px; }
body.readable-page .copy-button:hover { text-decoration-thickness: 2px; }
body.readable-page .copy-status { flex-basis: 100%; min-height: 38px; max-width: 36em; color: var(--fg-2); }
body.readable-page .wechat-qr { width: 280px; max-width: 100%; margin: 0 0 19px; }
body.readable-page .wechat-qr > a { display: block; padding: 8px; background: #fff; border: 1px solid var(--border); border-radius: 8px; }
body.readable-page .wechat-qr img { width: 100%; aspect-ratio: 1; object-fit: contain; }
body.readable-page .wechat-qr figcaption { margin-top: 8px; color: var(--fg-2); }
body.readable-page .site-footer { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 12px 24px; min-height: 88px; font-size: 20px; color: var(--fg-2); }
body.readable-page .site-footer :is(a, p) { display: inline-flex; align-items: center; gap: 6px; min-height: 52px; font-size: 20px; line-height: 1.9; }
body.readable-page .clipboard-helper { position: fixed; top: 0; left: -9999px; width: 1px; height: 1px; padding: 0; border: 0; opacity: 0; font-size: 20px; }

/* 精细指针只提供短促的反馈；触屏和减少动态效果偏好沿用静态原生链接。 */
@media (hover: hover) and (pointer: fine) and (prefers-reduced-motion: no-preference) {
  body.readable-page .site-nav a { position: relative; }
  body.readable-page .site-nav a::after { content: ""; position: absolute; inset-inline: 0; bottom: 5px; height: 2px; background: currentColor; transform: scaleX(0); transform-origin: left; transition: transform var(--motion-fast) ease-out; }
  body.readable-page .site-nav a:hover { text-decoration: none; }
  body.readable-page .site-nav a:is(:hover, :focus-visible)::after { transform: scaleX(1); }
  body.readable-page :is(.button, .btn):hover { transform: translateY(-2px); }
  body.readable-page :is(.button, .btn, .copy-button):active { transform: translateY(1px); }
  body.readable-page :is(.button, .btn, .copy-button):disabled { transform: none; }
  body.readable-page :is(.text-link, .back-link, .fde-link, .detail-related a, .button, .btn, .email-link, .site-nav a, .site-footer a) > span[aria-hidden="true"] { transition: transform var(--motion-fast) ease-out; }
  body.readable-page :is(.text-link, .back-link, .fde-link, .detail-related a, .button, .btn, .email-link, .site-nav a, .site-footer a):hover > span[aria-hidden="true"] { transform: translateX(3px); }
  /* 只缩放项目截图；二维码保持原图、原位和原有尺寸。 */
  body.readable-page :is(.project-image a, .screenshot-link) { overflow: hidden; }
  body.readable-page :is(.project-image a, .screenshot-link) img { transition: transform 240ms ease-out; }
  body.readable-page :is(.project-image a, .screenshot-link):hover img { transform: scale(1.015); }
}

@media (max-width: 1100px) {
  body.readable-page .contact-layout { grid-template-columns: 1fr; gap: 32px; }
}

@media (max-width: 900px) {
  body.readable-page :is(.wrap, .container) { width: calc(100% - 64px); }
}

/* 统一手机断点，320宽时页眉自然换行；不缩小正文或操作标签来挤入一行。 */
@media (max-width: 639px) {
  :root { --ui-section-space: 42px; }
  body.readable-page, body.readable-page p { font-size: 22px; line-height: 1.9; }
  body.readable-page :is(.questions dt, .questions dd) { font-size: 22px; }
  body.readable-page :is(.eyebrow, .small-label, .detail-note, .signature-note, .contact-hint, .copy-status, figcaption, .hero-experience) { font-size: 20px; }
  body.readable-page :is(.wrap, .container) { width: calc(100% - 40px); }
  body.readable-page .site-header { flex-direction: column; align-items: flex-start; gap: 8px; padding-block: 12px; }
  body.readable-page .wordmark { font-size: 32px; }
  body.readable-page .site-nav { width: 100%; justify-content: flex-start; gap: 4px 18px; }
  body.readable-page .site-nav a { font-size: 20px; }
  body.readable-page .email-link { font-size: 22px; }
  body.readable-page .site-footer { align-items: flex-start; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  /* 同等选择器权重关闭控件渐变，避免前面的a/button公共规则覆盖低权重通配规则。 */
  body.readable-page :is(a, button) { transition: none; }
  body.readable-page *, body.readable-page *::before, body.readable-page *::after { transition: none; }
  /* 减少动态效果时，按钮悬停及按下保持原位，同时覆盖公共交互状态的位移。 */
  body.readable-page :is(.button, .btn, .copy-button):is(:hover, :active) { transform: none; }
  body.readable-page :is(.text-link, .back-link, .fde-link, .detail-related a, .button, .btn, .email-link, .site-nav a, .site-footer a):is(:hover, :active) > span[aria-hidden="true"],
  body.readable-page :is(.project-image a, .screenshot-link):hover img { transform: none; }
}