/* ==========================================================================
   拙安官网 zhuoan.net
   视觉基准：文档/01-品牌定位/品牌资产/资产说明.md
   朱砂 #B64738 · 暖纸 #F5F1E8 · 墨色 #27312F
   ========================================================================== */

/* 衬线标题字体：自托管 Noto Serif SC 子集（SIL OFL 1.1，许可证与再生成
   脚本在 assets/fonts/ 下）。不加载时 Windows 会回落到 SimSun，大字号
   标题发虚；子集化后单字重约 1.6MB，swap 期间先显示系统宋体。 */
@font-face {
  font-family: 'Noto Serif SC';
  font-style: normal;
  font-weight: 400;
  font-display: swap;
  src: url("../assets/fonts/noto-serif-sc-400.woff2") format("woff2");
}

@font-face {
  font-family: 'Noto Serif SC';
  font-style: normal;
  font-weight: 600;
  font-display: swap;
  src: url("../assets/fonts/noto-serif-sc-600.woff2") format("woff2");
}

:root {
  --paper: #F7F4EC;
  --paper-deep: #F0EBE0;
  --surface: #FFFFFF;
  --surface-soft: #FBF9F4;

  --ink: #22261F;
  --ink-soft: #565C51;
  --ink-faint: #8B9086;

  --line: rgba(34, 38, 31, 0.11);
  --line-strong: rgba(34, 38, 31, 0.2);

  --cinnabar: #B64738;
  --cinnabar-ink: #A33F31;
  --cinnabar-wash: rgba(182, 71, 56, 0.07);
  --cinnabar-edge: rgba(182, 71, 56, 0.22);

  --shadow-soft: 0 1px 2px rgba(34, 38, 31, 0.04), 0 8px 24px rgba(34, 38, 31, 0.05);
  --shadow-lift: 0 2px 4px rgba(34, 38, 31, 0.05), 0 18px 44px rgba(34, 38, 31, 0.09);

  --serif: 'Noto Serif SC', 'Source Han Serif SC', 'Songti SC', 'SimSun', Georgia, serif;
  --sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'HarmonyOS Sans SC',
          'Microsoft YaHei', system-ui, sans-serif;
  --mono: 'SFMono-Regular', ui-monospace, Consolas, 'Liberation Mono', monospace;

  --nav-h: 64px;
  --radius: 14px;
  --radius-lg: 22px;
  --ease: cubic-bezier(0.2, 0.8, 0.3, 1);
  --shell: 1120px;

  /* 标识取色，依《品牌资产·使用规范》：浅色背景用朱砂，深色背景用暖纸反白。
     定义在共享样式里，十个页面走同一条规则。 */
  --h-seal: var(--cinnabar);
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --paper: #14170F;
    --paper-deep: #101309;
    --surface: #1B1F18;
    --surface-soft: #20241D;

    --ink: #EFECE2;
    --ink-soft: #A9AEA2;
    --ink-faint: #767B70;

    --line: rgba(239, 236, 226, 0.11);
    --line-strong: rgba(239, 236, 226, 0.22);

    --cinnabar-ink: #DC7A65;
    --cinnabar-wash: rgba(182, 71, 56, 0.14);
    --cinnabar-edge: rgba(182, 71, 56, 0.34);

    --h-seal: #F5F1E8;

    --shadow-soft: 0 1px 2px rgba(0, 0, 0, 0.3), 0 8px 24px rgba(0, 0, 0, 0.28);
    --shadow-lift: 0 2px 4px rgba(0, 0, 0, 0.3), 0 18px 44px rgba(0, 0, 0, 0.4);
  }
}

:root[data-theme="dark"] {
  --paper: #14170F;
  --paper-deep: #101309;
  --surface: #1B1F18;
  --surface-soft: #20241D;

  --ink: #EFECE2;
  --ink-soft: #A9AEA2;
  --ink-faint: #767B70;

  --line: rgba(239, 236, 226, 0.11);
  --line-strong: rgba(239, 236, 226, 0.22);

  --cinnabar-ink: #DC7A65;
  --cinnabar-wash: rgba(182, 71, 56, 0.14);
  --cinnabar-edge: rgba(182, 71, 56, 0.34);

  --h-seal: #F5F1E8;

  --shadow-soft: 0 1px 2px rgba(0, 0, 0, 0.3), 0 8px 24px rgba(0, 0, 0, 0.28);
  --shadow-lift: 0 2px 4px rgba(0, 0, 0, 0.3), 0 18px 44px rgba(0, 0, 0, 0.4);
}

/* --------------------------------------------------------------- 基础 */

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

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

/* 标题用 600 而不是 700：中文宋体没有 700 真字重时浏览器合成伪粗体，
   笔画发糊；已加载的 Noto Serif SC 提供 400/600 两个真字重。 */
h1, h2, h3, h4 {
  font-family: var(--serif);
  font-weight: 600;
  line-height: 1.35;
  margin: 0;
  letter-spacing: 0.01em;
  text-wrap: balance;
}

p { margin: 0; }
ul, ol { margin: 0; padding: 0; }
img, svg { max-width: 100%; }

/* 中文排版细节：行首「悬挂、行尾标点齐边；避免末行孤字。
   浏览器不支持时静默忽略，属渐进增强。 */
p, li, figcaption, summary {
  hanging-punctuation: first allow-end;
  text-wrap: pretty;
}

a { color: inherit; }

/* 选中色跟随朱砂；浏览器默认蓝在暖纸底上很跳 */
::selection {
  background: rgba(182, 71, 56, 0.2);
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) ::selection {
    background: rgba(220, 122, 101, 0.32);
  }
}
:root[data-theme="dark"] ::selection {
  background: rgba(220, 122, 101, 0.32);
}

:where(a, button, summary, input):focus-visible {
  outline: 2px solid var(--cinnabar-ink);
  outline-offset: 3px;
  border-radius: 4px;
}

.shell {
  width: 100%;
  max-width: var(--shell);
  margin: 0 auto;
  padding-inline: clamp(20px, 5vw, 40px);
}

/* 收窄是为了限制行长（单栏长文本铺满 1120px 一行会到七十多个字），
   但不该把左边缘一起挪走。容器仍与其他区块同宽以保住左边缘，
   只对内容限行长，页面从上到下的左对齐线因此不再中断。 */
.shell-narrow > * { max-width: 760px; }

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

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  z-index: 300;
  background: var(--cinnabar);
  color: #fff;
  padding: 12px 20px;
  font-size: 14px;
  border-radius: 0 0 var(--radius) 0;
  text-decoration: none;
}
.skip-link:focus { left: 0; }

/* --------------------------------------------------------------- 导航 */

.nav {
  position: sticky;
  top: 0;
  z-index: 200;
  background: color-mix(in srgb, var(--paper) 86%, transparent);
  backdrop-filter: saturate(1.4) blur(14px);
  -webkit-backdrop-filter: saturate(1.4) blur(14px);
  border-bottom: 1px solid transparent;
  transition: border-color 0.3s var(--ease);
}

.nav.is-stuck { border-bottom-color: var(--line); }

.nav-inner {
  height: var(--nav-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.logo {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  flex-shrink: 0;
}

.logo svg { width: 27px; height: 27px; display: block; color: var(--h-seal); }

.logo-name {
  font-family: var(--serif);
  font-size: 20px;
  font-weight: 600;
  letter-spacing: 0.06em;
  color: var(--ink);
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: clamp(18px, 2.6vw, 34px);
  list-style: none;
}

.nav-menu a {
  text-decoration: none;
  font-size: 14.5px;
  color: var(--ink-soft);
  padding: 6px 0;
  position: relative;
  white-space: nowrap;
  transition: color 0.2s var(--ease);
}

.nav-menu a::after {
  content: "";
  position: absolute;
  left: 0; right: 0; bottom: 0;
  height: 1.5px;
  background: var(--cinnabar);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.25s var(--ease);
}

.nav-menu a:hover { color: var(--ink); }
.nav-menu a:hover::after { transform: scaleX(1); }
.nav-menu a[aria-current="page"] { color: var(--ink); }
.nav-menu a[aria-current="page"]::after { transform: scaleX(1); }

.nav-tools { display: flex; align-items: center; gap: 8px; flex-shrink: 0; }

.icon-btn {
  width: 38px; height: 38px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--line);
  border-radius: 50%;
  background: transparent;
  color: var(--ink-soft);
  cursor: pointer;
  padding: 0;
  transition: border-color 0.2s var(--ease), color 0.2s var(--ease);
}

.icon-btn:hover { border-color: var(--line-strong); color: var(--ink); }
.icon-btn svg { width: 17px; height: 17px; }

.nav-burger { display: none; }

/* 主题按钮：亮色时显示月亮（可切到暗色），暗色时显示太阳 */
.icon-sun { display: none; }
.icon-moon { display: block; }

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .icon-sun { display: block; }
  :root:not([data-theme="light"]) .icon-moon { display: none; }
}

:root[data-theme="dark"] .icon-sun { display: block; }
:root[data-theme="dark"] .icon-moon { display: none; }
:root[data-theme="light"] .icon-sun { display: none; }
:root[data-theme="light"] .icon-moon { display: block; }

@media (max-width: 860px) {
  .nav-burger { display: inline-flex; }

  .nav-menu {
    position: fixed;
    inset: var(--nav-h) 0 auto 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    background: var(--surface);
    border-bottom: 1px solid var(--line);
    box-shadow: var(--shadow-lift);
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.35s var(--ease);
  }

  .nav-menu.open { max-height: 60vh; }

  .nav-menu a {
    display: block;
    padding: 17px clamp(20px, 5vw, 40px);
    font-size: 16px;
    border-bottom: 1px solid var(--line);
  }

  .nav-menu a::after { display: none; }
  .nav-menu a[aria-current="page"] { color: var(--cinnabar-ink); }
}

/* --------------------------------------------------------------- 通用块 */

.section { padding: clamp(64px, 9vw, 108px) 0; }
.section-sm { padding: clamp(48px, 7vw, 80px) 0; }
.section-line { border-top: 1px solid var(--line); }

.eyebrow {
  display: block;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--cinnabar-ink);
  margin-bottom: 14px;
}

.h-xl { font-size: clamp(38px, 7vw, 66px); letter-spacing: 0.06em; }
.h-lg { font-size: clamp(27px, 3.6vw, 38px); }
.h-md { font-size: clamp(21px, 2.4vw, 26px); }

.lede {
  font-size: clamp(16px, 1.5vw, 18px);
  line-height: 1.9;
  color: var(--ink-soft);
  max-width: 62ch;
}

.body-text {
  font-size: 15.5px;
  line-height: 1.95;
  color: var(--ink-soft);
  max-width: 68ch;
}

.body-text + .body-text { margin-top: 18px; }
.body-text strong { color: var(--ink); font-weight: 600; }

.block-head { margin-bottom: clamp(32px, 4vw, 48px); }
.block-head .lede { margin-top: 16px; }

.mono { font-family: var(--mono); font-size: 0.9em; }

.link {
  color: var(--cinnabar-ink);
  text-decoration: none;
  border-bottom: 1px solid var(--cinnabar-edge);
  transition: border-color 0.2s var(--ease);
}
.link:hover { border-bottom-color: var(--cinnabar-ink); }

.arrow-link {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  color: var(--cinnabar-ink);
  text-decoration: none;
  font-size: 15px;
  font-weight: 500;
}

.arrow-link::after {
  content: "→";
  transition: transform 0.25s var(--ease);
}

.arrow-link:hover::after { transform: translateX(4px); }

/* --------------------------------------------------------------- 按钮 */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 13px 26px;
  border-radius: 999px;
  font-family: var(--sans);
  font-size: 15px;
  font-weight: 500;
  text-decoration: none;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform 0.2s var(--ease), background 0.2s var(--ease), border-color 0.2s var(--ease);
}

.btn-primary { background: var(--cinnabar); color: #FFF6F2; }
.btn-primary:hover { background: #A33F31; transform: translateY(-1px); }

.btn-quiet {
  background: transparent;
  color: var(--ink);
  border-color: var(--line-strong);
}
.btn-quiet:hover { border-color: var(--ink-faint); transform: translateY(-1px); }

.btn-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 34px;
}

/* --------------------------------------------------------------- 产品页头 */

.phead {
  padding: clamp(48px, 7vw, 88px) 0 clamp(36px, 5vw, 56px);
  position: relative;
}

.phead-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
  gap: clamp(32px, 5vw, 64px);
  align-items: center;
}

@media (max-width: 880px) {
  .phead-grid { grid-template-columns: 1fr; gap: 34px; }
}

.crumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  color: var(--ink-faint);
  margin-bottom: 22px;
  list-style: none;
  flex-wrap: wrap;
}

.crumb a { text-decoration: none; color: var(--ink-soft); }
.crumb a:hover { color: var(--cinnabar-ink); }
.crumb li::after { content: "/"; margin-left: 8px; opacity: 0.5; }
.crumb li:last-child::after { display: none; }

.phead-name {
  display: flex;
  align-items: baseline;
  gap: 14px;
  flex-wrap: wrap;
  margin-bottom: 18px;
}

.phead-en {
  font-family: var(--mono);
  font-size: 14px;
  color: var(--ink-faint);
  letter-spacing: 0.04em;
}

.plat-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 26px;
  list-style: none;
}

.plat {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 6px 14px;
  border: 1px solid var(--line);
  border-radius: 999px;
  font-size: 13px;
  color: var(--ink-soft);
  background: var(--surface);
}

.plat svg { width: 14px; height: 14px; color: var(--ink-faint); }

.phead-art {
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: var(--surface);
  padding: clamp(22px, 3vw, 34px);
  box-shadow: var(--shadow-soft);
}

.phead-art svg { width: 100%; height: auto; display: block; }

/* --------------------------------------------------------------- 能力网格 */

.feat-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(270px, 100%), 1fr));
  gap: clamp(20px, 2.6vw, 34px);
}

.feat {
  padding-top: 22px;
  border-top: 2px solid var(--cinnabar);
}

.feat-num {
  font-family: var(--mono);
  font-size: 12px;
  color: var(--cinnabar-ink);
  letter-spacing: 0.1em;
  display: block;
  margin-bottom: 10px;
}

.feat h3 { font-size: 18px; margin-bottom: 10px; }

.feat p {
  font-size: 14.5px;
  line-height: 1.85;
  color: var(--ink-soft);
}

/* 简明清单 */

.tick {
  list-style: none;
  display: grid;
  gap: 13px;
}

.tick li {
  position: relative;
  padding-left: 26px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-soft);
}

.tick li::before {
  content: "";
  position: absolute;
  left: 2px;
  top: 0.6em;
  width: 9px;
  height: 5px;
  border-left: 1.8px solid var(--cinnabar);
  border-bottom: 1.8px solid var(--cinnabar);
  transform: rotate(-45deg);
}

.tick li strong { color: var(--ink); font-weight: 600; }

.tick-two { grid-template-columns: repeat(auto-fit, minmax(min(300px, 100%), 1fr)); gap: 13px clamp(24px, 4vw, 48px); }

.dash {
  list-style: none;
  display: grid;
  gap: 12px;
}

.dash li {
  position: relative;
  padding-left: 22px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-soft);
}

.dash li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.86em;
  width: 11px;
  height: 1.5px;
  background: var(--ink-faint);
}

.dash li strong { color: var(--ink); font-weight: 600; }

/* --------------------------------------------------------------- 步骤 */

.steps {
  list-style: none;
  counter-reset: s;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(240px, 100%), 1fr));
  gap: clamp(20px, 3vw, 36px);
}

.steps li { counter-increment: s; }

.steps li::before {
  content: counter(s, decimal-leading-zero);
  display: block;
  font-family: var(--serif);
  font-size: 30px;
  color: var(--cinnabar);
  opacity: 0.45;
  line-height: 1;
  margin-bottom: 14px;
}

.steps h3 { font-size: 17px; margin-bottom: 9px; }

.steps p { font-size: 14.5px; line-height: 1.85; color: var(--ink-soft); }

/* --------------------------------------------------------------- 价格 */

.price-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(280px, 100%), 1fr));
  gap: clamp(16px, 2vw, 22px);
}

.price {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  padding: clamp(26px, 3vw, 34px);
  display: flex;
  flex-direction: column;
}

.price-featured { border-color: var(--cinnabar-edge); }

.price-name { font-size: 18px; margin-bottom: 10px; }

.price-tag {
  font-family: var(--serif);
  font-size: 34px;
  font-weight: 600;
  font-variant-numeric: tabular-nums;
  color: var(--cinnabar-ink);
  line-height: 1.2;
  margin-bottom: 6px;
}

.price-tag small {
  font-family: var(--sans);
  font-size: 14px;
  font-weight: 400;
  color: var(--ink-faint);
  margin-left: 4px;
}

.price-sub {
  font-size: 13.5px;
  color: var(--ink-faint);
  margin-bottom: 24px;
  line-height: 1.7;
}

.price .tick { margin-bottom: 20px; }

.price-note {
  margin-top: auto;
  padding-top: 18px;
  border-top: 1px solid var(--line);
  font-size: 13px;
  line-height: 1.75;
  color: var(--ink-faint);
}

/* --------------------------------------------------------------- 引言 / 提示 */

.pull {
  font-family: var(--serif);
  font-size: clamp(20px, 2.6vw, 27px);
  line-height: 1.75;
  color: var(--ink);
  border-left: 2px solid var(--cinnabar);
  padding-left: clamp(20px, 3vw, 32px);
  max-width: 24ch;
  text-wrap: balance;
}

/* 附注框此前没有行长上限，正文一行可跑到近 900px，
   而同页 .body-text 上限约 530px。统一到站上的 760px 阅读版心。 */
.note {
  max-width: 760px;
  border: 1px solid var(--line);
  border-left: 2px solid var(--cinnabar);
  border-radius: 0 var(--radius) var(--radius) 0;
  background: var(--surface);
  padding: 22px 26px;
  font-size: 14.5px;
  line-height: 1.85;
  color: var(--ink-soft);
}

.note strong { color: var(--ink); }
.note + .note { margin-top: 14px; }

/* --------------------------------------------------------------- 两栏 */

.duo {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr);
  gap: clamp(30px, 5vw, 72px);
  align-items: start;
}

/* 引文 + 正文的一对：引文只有两三行，正文有七八行，顶对齐会让引文
   孤零零吊在左上角。以引文为直接子元素时改为垂直居中。
   （about.html 里引文嵌在标题块内的那一处不受影响，仍是顶对齐。）*/
.duo:has(> .pull) { align-items: center; }

@media (max-width: 880px) { .duo { grid-template-columns: 1fr; gap: 28px; }
}

/* --------------------------------------------------------------- 下载 */

.dl-list { display: grid; gap: 16px; }

.dl {
  display: grid;
  grid-template-columns: 46px minmax(0, 1fr) auto;
  align-items: center;
  gap: clamp(14px, 2vw, 24px);
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  padding: clamp(20px, 2.4vw, 26px) clamp(20px, 2.6vw, 30px);
}

.dl-icon { color: var(--cinnabar); width: 46px; height: 46px; }
.dl-icon svg { width: 100%; height: 100%; }

.dl-title {
  font-family: var(--serif);
  font-size: 17px;
  font-weight: 600;
  margin-bottom: 5px;
}

.dl-meta { font-size: 13.5px; color: var(--ink-faint); line-height: 1.7; }

.dl-state {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 8px 16px;
  border-radius: 999px;
  border: 1px dashed var(--line-strong);
  font-size: 13px;
  color: var(--ink-faint);
  white-space: nowrap;
}

.dl-state::before {
  content: "";
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--ink-faint);
}

@media (max-width: 640px) {
  .dl { grid-template-columns: 40px minmax(0, 1fr); }
  .dl-icon { width: 40px; height: 40px; }
  .dl-state { grid-column: 1 / -1; justify-self: start; }
}

/* --------------------------------------------------------------- 常见问题 */

/* 两列：问句短、右侧空档大，单列时箭头会被甩到三百像素之外。
   align-items:start 保证展开一条时同行另一条不被拉高。 */
.faq {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  column-gap: clamp(28px, 4vw, 56px);
  align-items: start;
  border-top: 1px solid var(--line);
}

@media (max-width: 760px) { .faq { grid-template-columns: 1fr; }
}

.faq details { border-bottom: 1px solid var(--line); }

.faq summary {
  list-style: none;
  cursor: pointer;
  padding: 22px 44px 22px 0;
  position: relative;
  font-size: 16.5px;
  font-weight: 600;
  color: var(--ink);
}

.faq summary::-webkit-details-marker { display: none; }

.faq summary::after {
  content: "";
  position: absolute;
  right: 8px;
  top: 50%;
  width: 11px;
  height: 11px;
  border-right: 1.6px solid var(--cinnabar);
  border-bottom: 1.6px solid var(--cinnabar);
  /* 收起朝右（可以打开），展开朝下（内容在下方） */
  transform: translateY(-50%) rotate(-45deg);
  transition: transform 0.25s var(--ease);
}

.faq details[open] summary::after { transform: translateY(-70%) rotate(45deg); }

.faq p {
  padding: 0 0 24px;
  font-size: 15px;
  line-height: 1.95;
  color: var(--ink-soft);
  max-width: 72ch;
}

.faq p + p { padding-top: 0; margin-top: -10px; }

/* --------------------------------------------------------------- 收尾行动 */

/* 收尾是一整节，不是内容单元——卡片外衣会让它成为全页唯一被框起来的
   区块。与其他各节一样靠细线和间距分隔，左边缘也因此回到同一条线上。 */
.closer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: clamp(22px, 3vw, 40px);
  flex-wrap: wrap;
}

.closer p {
  font-size: 15px;
  line-height: 1.85;
  color: var(--ink-soft);
  margin-top: 10px;
  max-width: 52ch;
}

.closer .btn-row { margin-top: 0; }

/* 收尾卡带扫码入口：二维码本身就是主要动作，按钮降为次要，
   按钮改放在文字下方，右侧留给二维码。 */
.closer-qr .btn-row { margin-top: 24px; }
.closer-fig {
  margin: 0;
  display: grid;
  justify-items: center;
  gap: 10px;
  flex-shrink: 0;
}
.closer-fig .qr { justify-self: center; }
.closer-fig figcaption {
  font-size: 13px;
  color: var(--ink-faint);
  white-space: nowrap;
}

/* --------------------------------------------------------------- 页脚 */

.foot {
  border-top: 1px solid var(--line);
  padding: clamp(48px, 6vw, 72px) 0 32px;
  background: var(--paper-deep);
}

.foot-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.6fr) repeat(3, minmax(0, 1fr));
  gap: clamp(28px, 4vw, 48px);
  margin-bottom: clamp(36px, 5vw, 56px);
}

@media (max-width: 860px) { .foot-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 460px) { .foot-grid { grid-template-columns: 1fr; }
}

/* 页脚服务号栏：栏头带具名内容，字距收窄；二维码与右侧三栏首行对齐 */
/* 栏头以全角「」收尾：字形右半为空，再加末字字距，共约 0.72em 虚位。
   扣掉它，下方二维码才是对着墨迹居中而不是对着字框居中。 */
.foot-head-inline { letter-spacing: 0.08em; margin-right: -0.72em; }
.foot .qr-inline { margin-top: 0; }
/* 整栏宽度收到栏头文字宽，二维码在栏头下方居中 */
.foot-brand { width: max-content; max-width: 100%; }
.foot-brand .qr { margin-left: auto; margin-right: auto; }

.foot h2 {
  font-family: var(--sans);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-faint);
  margin-bottom: 16px;
}

.foot ul { list-style: none; display: grid; gap: 11px; }

.foot a {
  text-decoration: none;
  font-size: 14.5px;
  color: var(--ink-soft);
  transition: color 0.2s var(--ease);
  word-break: break-word;
}

.foot a:hover { color: var(--cinnabar-ink); }

.foot-base {
  border-top: 1px solid var(--line);
  padding-top: 26px;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 8px 26px;
  font-size: 12.5px;
  color: var(--ink-faint);
}

/* 底栏是两端对齐；换行后各占一行，此时靠左排更自然 */
@media (max-width: 560px) { .foot-base { justify-content: flex-start; }
}

.foot-base a {
  font-size: inherit;
  color: inherit;
}

/* --------------------------------------------------------------- 错误页 */

.err { padding: clamp(80px, 14vw, 160px) 0 clamp(48px, 7vw, 80px); }
.err .h-xl { font-size: clamp(30px, 5vw, 46px); letter-spacing: 0.02em; }

.err-code {
  font-family: var(--mono);
  font-size: 13px;
  letter-spacing: 0.24em;
  color: var(--cinnabar-ink);
  margin-bottom: 18px;
  display: block;
}

/* --------------------------------------------------------------- 产品示意图 */

.art { display: block; width: 100%; height: auto; }

.art-cell {
  fill: none;
  stroke: currentColor;
  stroke-width: 1;
  opacity: 0.22;
}

.art-rule {
  stroke: currentColor;
  stroke-width: 1;
  opacity: 0.2;
}
.art-red { fill: var(--cinnabar); }
.art-red-s { fill: none; stroke: var(--cinnabar); stroke-width: 1.6; stroke-linecap: round; }

.art-stroke {
  fill: none;
  stroke: currentColor;
  stroke-width: 1.4;
  stroke-linecap: round;
  stroke-linejoin: round;
  opacity: 0.55;
}

.art-dash {
  stroke: var(--cinnabar);
  stroke-width: 1.4;
  stroke-dasharray: 3 5;
  stroke-linecap: round;
  opacity: 0.75;
}

.art text { font-family: var(--sans); }
.art-mid { text-anchor: middle; }

.art-label {
  fill: var(--ink-faint);
  font-size: 12px;
}

.art-key {
  fill: var(--ink);
  font-family: var(--serif);
  font-size: 14px;
  font-weight: 600;
}

/* --------------------------------------------------------------- 入场动效 */

/* 由 script.js 给目标元素加 .reveal，进入视口时再加 .in；--reveal-d 用于
   同屏多个元素的错峰。无脚本时不存在 .reveal，内容直接可见——动效只是
   增强，不是渲染前提。幅度刻意小（8px、0.55s），和全站克制的动效一致。 */
.reveal {
  opacity: 0;
  transform: translateY(8px);
  transition:
    opacity 0.55s var(--ease) var(--reveal-d, 0ms),
    transform 0.55s var(--ease) var(--reveal-d, 0ms);
}

.reveal.in {
  opacity: 1;
  transform: none;
}

@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
}

/* --------------------------------------------------------------- 二维码 */

.qr {
  width: 118px;
  height: 118px;
  border-radius: 10px;
  border: 1px solid var(--line);
  background: #FFFFFF;
  padding: 6px;
  display: block;
  justify-self: end;
}

.qr-inline {
  margin-top: 20px;
  justify-self: start;
}

@media (max-width: 640px) {
  .dl-qr .qr { grid-column: 1 / -1; justify-self: start; }
}