/* ==========================================================================
   退货核验系统官网
   配色：Apple 官网 —— 白底 / #f5f5f7 浅灰分区，深色只用于首屏(#000)与安装包(#1d1d1f)；
   唯一强调色 Apple 蓝（#06c / #0071e3 / #2997ff），无第二个彩色。
   零依赖：不含任何 CDN / 框架 / 外部字体 / 毛玻璃（backdrop-filter 在微信内置
   浏览器与老 Safari 上会糊，改用纯色底 + 发丝分隔线）。
   ========================================================================== */

:root {
  --ink: #1d1d1f;            /* 主文本 on #fff = 16.1:1 */
  --ink-2: #6e6e73;          /* 次级正文 = 5.0:1 */
  --ink-3: #86868b;          /* 辅助标注（≥4.5:1，仅用于 12px 以上） */
  --bg-0: #ffffff;
  --bg-1: #f5f5f7;
  --bg-2: #f5f5f7;
  --line: #d2d2d7;
  --line-2: #c2c2c7;
  --link: #06c;
  --btn: #0071e3;
  --btn-hover: #0077ed;
  --focus: #0071e3;
  --radius: 18px;
  --radius-lg: 28px;
  --max: 1400px;             /* 正文栅格 */
  --max-wide: 1560px;        /* FAQ / 下载 / 页脚栅格 */
  --max-hero: 1560px;
  --max-shots: 1448px;       /* 截图栅格：≈ 源图 1440 宽，1:1 不放大虚化 */
  --nav-h: 60px;
  --font: "PingFang SC", "HarmonyOS Sans SC", "Source Han Sans SC", "Noto Sans SC",
          -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", sans-serif;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "PingFang SC", monospace;
}

/* 深色区块（首屏 / 安装包 / 大图弹层）：只换 token，结构与交互完全不变 */
.hero, #download, .lb {
  --ink: #f5f5f7;
  --ink-2: #a1a1a6;
  --ink-3: #86868b;
  --bg-0: #000000;
  --bg-1: #161617;
  --bg-2: #1d1d1f;
  --line: rgba(255, 255, 255, .18);
  --line-2: rgba(255, 255, 255, .32);
  --link: #2997ff;
  --btn: #0071e3;
  --btn-hover: #2997ff;
  --focus: #2997ff;
  /* 必须显式给 color：h1/h2/h3 没有自己的 color 声明，
     只会继承 body 的计算值（浅色 #1d1d1f），在深底上会隐形。 */
  color: var(--ink);
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font-family: var(--font);
  color: var(--ink);
  background: var(--bg-0);
  -webkit-font-smoothing: antialiased;
}
h1, h2, h3, h4, p, dl, dd, figure, ol, ul { margin: 0; }
ol, ul { padding: 0; list-style: none; }
img { display: block; max-width: 100%; height: auto; }
a { color: var(--link); text-decoration: none; }
code { font-family: var(--mono); }
:focus-visible { outline: 2px solid var(--focus); outline-offset: 3px; border-radius: 6px; }

.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 {
  position: absolute; left: 16px; top: -60px; z-index: 200;
  padding: 10px 18px; border-radius: 0 0 10px 10px;
  background: var(--btn); color: #fff; font-size: 14px; font-weight: 600;
}
.skip:focus { top: 0; }

/* ----------------------------------------------------------------- 栅格 */
.wrap { width: min(var(--max), 92vw); margin: 0 auto; }
.wrap--wide { width: min(var(--max-wide), 94vw); margin: 0 auto; }
.wrap--shots { width: min(var(--max-shots), 94vw); margin: 0 auto; }
.wrap--hero { width: min(var(--max-hero), 94vw); margin: 0 auto; }
:target, .sec, #download { scroll-margin-top: calc(var(--nav-h) + 16px); }

/* --------------------------------------------------------------- 导航 */
.nav {
  position: sticky; top: 0; z-index: 100;
  background: #fff;                        /* 纯色，不用 backdrop-filter */
  border-bottom: 1px solid var(--line);
}
.nav__in { display: flex; align-items: center; gap: 28px; height: var(--nav-h); }
.nav__brand {
  display: flex; align-items: center; gap: 9px;
  color: var(--ink); font-size: 15px; font-weight: 600; letter-spacing: .01em;
}
.nav__mark {
  width: 10px; height: 18px; border-radius: 2px;
  background: linear-gradient(180deg, #0071e3, rgba(0, 113, 227, .22));
  box-shadow: 0 0 12px rgba(0, 113, 227, .28);
}
.nav__links { display: flex; gap: 26px; }
.nav__links a { color: var(--ink); font-size: 13px; opacity: .88; }
.nav__links a:hover { color: var(--link); opacity: 1; text-decoration: none; }
.nav__cta { margin-left: auto; }
.nav__toggle {
  display: none; margin-left: 8px; padding: 10px; cursor: pointer;
  background: none; border: 1px solid var(--line-2); border-radius: 10px; color: var(--ink);
}
.nav__bars { display: grid; gap: 4px; }
.nav__bars i { display: block; width: 18px; height: 1.5px; background: currentColor; }
.nav__panel { display: none; }

/* --------------------------------------------------------------- 按钮 */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  padding: 12px 24px; border-radius: 980px; border: 1px solid transparent;
  font-size: 16px; font-weight: 400; line-height: 1.2; cursor: pointer;
}
.btn--sm { padding: 7px 15px; font-size: 13px; }
.btn--solid { background: var(--btn); color: #fff; }
.btn--solid:hover { background: var(--btn-hover); text-decoration: none; }
.btn--line { background: transparent; color: var(--link); border-color: currentColor; }
.btn--line:hover { text-decoration: none; }
.btn--off {
  justify-self: start; background: transparent; color: var(--ink-3);
  border: 1px solid var(--line); border-radius: 8px; cursor: not-allowed;
  padding: 8px 14px; font-size: 13px; font-family: var(--mono);
}
.lias { display: inline-flex; align-items: baseline; gap: 5px; font-size: 17px; }
.lias::after { content: "›"; font-size: 19px; }

/* --------------------------------------------------- 标签 / 区块标题 */
.tag {
  font-family: var(--mono); font-size: 12px; letter-spacing: .16em;
  color: var(--link); margin-bottom: 14px;
}
.tag::before { content: "// "; color: var(--ink-3); }
.sec { padding: clamp(56px, 7vw, 108px) 0; }
.sec h2 {
  font-size: clamp(26px, 2.8vw, 44px); line-height: 1.14;
  letter-spacing: -.02em; font-weight: 600; max-width: 22em;
}
.sec__note { margin-top: 14px; font-size: 15px; color: var(--ink-2); max-width: 62ch; }
.sec--alt { background: var(--bg-1); border-block: 1px solid var(--line); }

/* --------------------------------------------------------------- 首屏（深色 #000） */
.hero { position: relative; padding: clamp(40px, 5vw, 76px) 0 0; overflow: hidden; background: #000; }
.hero__grid {
  position: absolute; inset: 0; pointer-events: none; opacity: .55;
  background-image: linear-gradient(rgba(255, 255, 255, .07) 1px, transparent 1px),
                    linear-gradient(90deg, rgba(255, 255, 255, .07) 1px, transparent 1px);
  background-size: 72px 72px;
  -webkit-mask-image: radial-gradient(120% 72% at 50% 0%, #000 8%, transparent 72%);
          mask-image: radial-gradient(120% 72% at 50% 0%, #000 8%, transparent 72%);
}
.hero__glow {
  position: absolute; left: 50%; top: -340px; width: 1100px; height: 620px;
  transform: translateX(-50%); pointer-events: none;
  background: radial-gradient(closest-side, rgba(0, 113, 227, .3), transparent 72%);
}
.hero__top {
  position: relative; display: grid; gap: clamp(28px, 3.4vw, 56px);
  grid-template-columns: minmax(0, 1.05fr) minmax(0, .95fr);
  align-items: center; padding-bottom: clamp(32px, 4vw, 60px);
}
.hero__copy h1 {
  font-size: clamp(36px, 5.4vw, 72px); line-height: 1.04;
  letter-spacing: -.03em; font-weight: 600;
}
.lede { margin-top: 20px; font-size: clamp(16px, 1.25vw, 19px); line-height: 1.62; color: var(--ink-2); max-width: 40ch; }
.hero__cta { display: flex; flex-wrap: wrap; gap: 14px; margin-top: 28px; }

.spec { border-top: 1px solid var(--line); }
.spec__row {
  display: grid; grid-template-columns: 88px 1fr; gap: 18px;
  padding: 14px 0; border-bottom: 1px solid var(--line); align-items: baseline;
}
.spec dt { font-size: 13px; color: var(--ink-3); }
.spec dd { font-family: var(--mono); font-size: 19px; color: var(--ink); letter-spacing: .01em; }
.spec dd span {
  display: block; margin-top: 5px; font-family: var(--font);
  font-size: 13.5px; line-height: 1.55; color: var(--ink-2); letter-spacing: 0;
}

/* 首屏大图：页面上唯一「发光的窗口」 */
.stage {
  position: relative; border: 1px solid var(--line); border-bottom: 0;
  border-radius: var(--radius-lg) var(--radius-lg) 0 0; overflow: hidden;
  background: var(--bg-2);
  box-shadow: 0 30px 70px rgba(0, 0, 0, .6);
}
.stage::after {
  content: ""; position: absolute; left: 0; right: 0; top: 0; height: 2px;
  background: linear-gradient(90deg, transparent, rgba(41, 151, 255, .85), transparent);
}
.stage__bar {
  display: flex; align-items: center; gap: 12px; padding: 10px 16px;
  background: var(--bg-2); border-bottom: 1px solid var(--line);
}
.stage__dots { display: flex; gap: 6px; }
.stage__dots i { width: 9px; height: 9px; border-radius: 50%; background: var(--line-2); }
.stage__dots i:first-child { background: #2997ff; }
.stage__name { font-family: var(--mono); font-size: 12px; color: var(--ink-3); letter-spacing: .04em; }
.stage img { width: 100%; }

/* ------------------------------------------------------------- 工作流 */
.flow {
  margin-top: clamp(32px, 3.6vw, 52px);
  display: grid; gap: 1px; grid-template-columns: repeat(4, 1fr);
  background: var(--line); border: 1px solid var(--line); border-radius: var(--radius);
  overflow: hidden;
}
.flow__step { padding: 26px 22px 28px; background: #fff; }
.flow__no {
  display: block; font-family: var(--mono); font-size: 12px;
  letter-spacing: .14em; color: var(--link); margin-bottom: 16px;
}
.flow__step h3 { font-size: 19px; font-weight: 600; letter-spacing: -.01em; }
.flow__step p { margin-top: 8px; font-size: 14.5px; line-height: 1.6; color: var(--ink-2); }

/* ------------------------------------------------------------- 功能 */
.feats {
  margin-top: clamp(32px, 3.6vw, 52px);
  display: grid; gap: 14px; grid-template-columns: repeat(3, 1fr);
}
.feat {
  display: flex; gap: 16px; padding: 24px 22px;
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
}
.feat__ico { flex: none; width: 26px; height: 26px; color: var(--link); margin-top: 2px; }
.feat h3 { font-size: 16.5px; font-weight: 600; letter-spacing: -.01em; }
.feat p { margin-top: 6px; font-size: 14px; line-height: 1.6; color: var(--ink-2); }

/* ------------------------------------------------------- 界面预览 */
/* 截图区：宽屏 3 列 × 2 排（客户 2026-10-10 定），窄屏 2 列 / 1 列。
   卡内只求「一眼看清页面长什么样」，细节靠点开原生 dialog 看 1440 原图。 */
.shots {
  margin-top: clamp(30px, 3.4vw, 48px);
  display: grid; gap: clamp(18px, 1.8vw, 24px);
  grid-template-columns: repeat(3, minmax(0, 1fr));
}
.shot { margin: 0; }
.shot__btn {
  display: block; width: 100%; padding: 0; cursor: zoom-in; position: relative;
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  overflow: hidden; box-shadow: 0 10px 30px rgba(0, 0, 0, .06);
}
.shot__btn img { width: 100%; }
.shot__zoom {
  position: absolute; right: 14px; bottom: 14px; padding: 7px 14px; border-radius: 980px;
  background: rgba(255, 255, 255, .92); color: var(--ink); font-size: 12.5px;
  border: 1px solid var(--line); opacity: 0;
}
.shot figcaption {
  display: flex; align-items: baseline; gap: 12px; flex-wrap: wrap;
  margin-top: 14px; padding-top: 13px; border-top: 1px solid var(--line);
}
.shot figcaption b { font-size: 16.5px; font-weight: 600; letter-spacing: -.01em; }
.shot figcaption span { font-size: 14px; color: var(--ink-2); }

/* --------------------------------------------- 获取安装包（深色 #1d1d1f） */
#download { background: #1d1d1f; }
.dl {
  display: grid; gap: clamp(24px, 2.6vw, 40px);
  grid-template-columns: minmax(0, .95fr) minmax(0, 1fr) minmax(0, 1fr);
  align-items: stretch;
}
.dl__lead p:not(.tag) { margin-top: 18px; font-size: 15.5px; line-height: 1.7; color: var(--ink-2); }
.dl__sys { font-size: 13.5px !important; color: var(--ink-3) !important; }
.dl__lead .lias { margin-top: 22px; }
.dl__cards { display: contents; }   /* 两张卡直接参与 .dl 的三栏栅格 */
.card {
  display: grid; gap: 10px; padding: 26px 26px 28px;
  background: #000; border: 1px solid var(--line); border-radius: var(--radius);
}
.card h3 { font-size: 21px; font-weight: 600; letter-spacing: -.015em; }
.card p { font-size: 14.5px; line-height: 1.68; color: var(--ink-2); }
.card code { font-size: 13px; padding: 1px 6px; border: 1px solid var(--line); border-radius: 5px; }
/* 状态 chip：选择器需比 `.card p`（0,1,1）更具体，否则会被正文样式盖掉 */
.card .card__state {
  justify-self: start; padding: 4px 10px; border-radius: 980px;
  font-family: var(--mono); font-size: 11.5px; line-height: 1.6; letter-spacing: .1em;
}
.card .card__state--ok { color: #30d158; border: 1px solid rgba(48, 209, 88, .45); background: rgba(48, 209, 88, .12); }
.card .card__state--wait { color: #ffd60a; border: 1px solid rgba(255, 214, 10, .4); background: rgba(255, 214, 10, .1); }

/* ------------------------------------------------------------- FAQ */
.faq {
  margin-top: clamp(30px, 3.4vw, 48px);
  display: grid; gap: 0 clamp(40px, 4vw, 72px); grid-template-columns: repeat(2, minmax(0, 1fr));
}
.faq details { border-bottom: 1px solid var(--line); }
.faq summary {
  list-style: none; cursor: pointer; position: relative;
  padding: 20px 40px 20px 0; font-size: 17px; font-weight: 600; letter-spacing: -.01em;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after {
  content: "+"; position: absolute; right: 8px; top: 50%; transform: translateY(-50%);
  font-size: 22px; font-weight: 400; color: var(--ink-3); font-family: var(--mono);
}
.faq details[open] summary::after { content: "−"; }
.faq details p { padding: 0 36px 20px 0; font-size: 15px; line-height: 1.68; color: var(--ink-2); }

/* ------------------------------------------------------------- 页脚 */
.foot { border-top: 1px solid var(--line); background: var(--bg-1); padding: 34px 0 40px; }
.foot__brand { font-size: 14px; font-weight: 600; }
.foot__links { display: flex; flex-wrap: wrap; gap: 8px 22px; margin-top: 14px; }
.foot__links a { font-size: 13px; color: var(--ink-2); }
.foot__note { margin-top: 18px; font-size: 12px; color: var(--ink-3); }
/* 手册页脚沿用旧结构（.foot__in > span） */
.foot__in > span { display: inline-block; margin-right: 16px; font-size: 13px; color: var(--ink-2); }
.foot__in > span a { color: var(--ink-2); text-decoration: underline; }

/* ------------------------------------------------- 大图弹层（常深色） */
.lb {
  width: min(1440px, 94vw); max-width: none; max-height: 92vh;
  padding: 0; border: 1px solid var(--line); border-radius: var(--radius);
  background: var(--bg-1); color: var(--ink); overflow: auto;
}
.lb::backdrop { background: rgba(0, 0, 0, .55); }
.lb__bar {
  position: sticky; top: 0; display: flex; align-items: center; justify-content: space-between;
  gap: 16px; padding: 12px 14px 12px 18px; background: var(--bg-2); border-bottom: 1px solid var(--line);
}
.lb__cap { font-family: var(--mono); font-size: 13px; color: var(--ink-2); }
.lb__x {
  display: grid; place-items: center; width: 36px; height: 36px; cursor: pointer;
  background: none; border: 1px solid var(--line-2); border-radius: 50%; color: var(--ink);
}
.lb__x svg { width: 16px; height: 16px; }
.lb__img { width: 100%; }

/* ============================================================== 使用手册 */
.doc { display: grid; grid-template-columns: 210px 1fr; gap: 44px; align-items: start; padding-top: 48px; }
.doc__nav { position: sticky; top: calc(var(--nav-h) + 20px); }
.doc__nav h4 { font-size: 12px; color: var(--ink-3); font-weight: 600; letter-spacing: .1em; }
.doc__nav a { display: block; padding: 7px 0; font-size: 14px; color: var(--ink-2); }
.doc__nav a:hover { color: var(--link); text-decoration: none; }
.doc__body > h2 {
  font-size: 30px; letter-spacing: -.02em; font-weight: 600; margin: 54px 0 4px;
  scroll-margin-top: calc(var(--nav-h) + 24px);
}
.doc__body > h2:first-child { margin-top: 0; }
.doc__body h3 { font-size: 20px; letter-spacing: -.015em; font-weight: 600; margin: 30px 0 10px; }
.doc__body p, .doc__body li { font-size: 16.5px; line-height: 1.72; color: var(--ink-2); }
.doc__body p + p { margin-top: 10px; }
.doc__body ul, .doc__body ol { margin: 12px 0 16px; padding-left: 22px; list-style: disc; }
.doc__body ol { list-style: decimal; }
.doc__body li { margin-bottom: 7px; }
.doc__body li b, .doc__body p b { color: var(--ink); }
.doc__body code {
  font-size: 14px; background: var(--bg-1);
  border: 1px solid var(--line); border-radius: 6px; padding: 1px 6px;
}
.doc__body figure { margin: 22px 0 30px; }
.doc__body figure img { width: 100%; border: 1px solid var(--line); border-radius: 12px; }
.doc__body figcaption { margin-top: 10px; font-size: 13px; color: var(--ink-3); }
.callout {
  margin: 22px 0; padding: 18px 20px; border-radius: 12px;
  background: var(--bg-1); border-left: 3px solid var(--link);
  font-size: 15.5px; line-height: 1.7; color: var(--ink-2);
}
.callout b { color: var(--ink); }
.callout--warn { border-left-color: #e5484d; background: #fdf1f1; }
.doc-table { width: 100%; border-collapse: collapse; margin: 16px 0 24px; font-size: 16px; }
.doc-table th, .doc-table td {
  border-bottom: 1px solid var(--line); padding: 12px 14px; text-align: left; vertical-align: top;
}
.doc-table th { font-weight: 600; color: var(--ink); width: 38%; }
.doc-table td { color: var(--ink-2); }

/* 三步上手 */
.quick {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px;
  margin: 40px 0 8px;
}
.quick > div { background: var(--bg-1); border: 1px solid var(--line); border-radius: var(--radius); padding: 22px; }
.quick b { display: block; font-size: 18px; font-weight: 600; margin-bottom: 6px; }
.quick span { font-size: 14.5px; line-height: 1.6; color: var(--ink-2); }

/* ============================================================== 动效 */
/* 只在用户未要求减少动效时启用；全部动效为 transform / opacity，不触发重排。 */
@media (prefers-reduced-motion: no-preference) {
  html { scroll-behavior: smooth; }
  .stage::before {
    content: ""; position: absolute; left: 0; right: 0; height: 34%; top: -34%;
    background: linear-gradient(180deg, transparent, rgba(41, 151, 255, .2) 55%, transparent);
    animation: sweep 8s cubic-bezier(.6, 0, .4, 1) infinite;
  }
  @keyframes sweep { 0% { top: -34%; } 60%, 100% { top: 100%; } }
  .shot__btn { transition: border-color .25s ease, transform .25s ease, box-shadow .25s ease; }
  .shot__btn:hover {
    border-color: var(--link); transform: translateY(-3px);
    box-shadow: 0 18px 44px rgba(0, 0, 0, .12);
  }
  .shot__btn:hover .shot__zoom { opacity: 1; }
  .feat, .card { transition: border-color .25s ease, box-shadow .25s ease; }
  .feat:hover { border-color: var(--line-2); }
  .card:hover { box-shadow: 0 10px 30px rgba(0, 0, 0, .35); }
  .btn, .lias, a { transition: color .2s ease, background-color .2s ease, border-color .2s ease; }
  .hero__copy, .spec, .stage { animation: rise .7s cubic-bezier(.22, .68, .3, 1) both; }
  .spec { animation-delay: .08s; }
  .stage { animation-delay: .16s; }
  @keyframes rise { from { opacity: 0; transform: translateY(14px); } to { opacity: 1; transform: none; } }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .shot__zoom { opacity: 1; }
}

/* ============================================================== 响应式 */
@media (max-width: 1180px) {
  .hero__top { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); }
}
@media (max-width: 1040px) {
  .flow { grid-template-columns: repeat(2, 1fr); }
  .feats { grid-template-columns: repeat(2, 1fr); }
  .shots { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .faq { grid-template-columns: minmax(0, 1fr); }
  .dl { grid-template-columns: minmax(0, 1fr); }
  .dl__cards { display: grid; gap: 16px; }
  .quick { grid-template-columns: 1fr; }
}
@media (max-width: 880px) {
  :root { --nav-h: 54px; }
  .nav__links { display: none; }
  .nav__cta { margin-left: auto; }
  .nav__toggle { display: block; }
  .nav__panel {
    display: grid; gap: 2px; padding: 10px 0 18px;
    border-top: 1px solid var(--line);
  }
  .nav__panel[hidden] { display: none; }
  .nav__panel a { padding: 11px 2px; font-size: 15px; color: var(--ink); border-bottom: 1px solid var(--line); }
  .nav__panel a:last-child { color: var(--link); border-bottom: 0; }

  .hero { padding-top: 34px; }
  .hero__top { grid-template-columns: minmax(0, 1fr); gap: 28px; }
  .lede { max-width: none; }
  .stage__zoom, .shot__zoom { display: none; }

  .sec { padding: 52px 0; }
  .sec h2 { max-width: none; }
  .shot figcaption { gap: 4px; }

  .doc { grid-template-columns: minmax(0, 1fr); gap: 22px; padding-top: 28px; }
  .doc__nav {
    position: static; display: flex; gap: 8px; overflow-x: auto;
    padding-bottom: 10px; -webkit-overflow-scrolling: touch;
  }
  .doc__nav h4 { display: none; }
  .doc__nav a {
    flex: none; padding: 7px 13px; border: 1px solid var(--line);
    border-radius: 980px; font-size: 13px; white-space: nowrap;
  }
  .doc__body > h2 { font-size: 25px; margin-top: 40px; }
  .doc__body p, .doc__body li { font-size: 16px; }
}
@media (max-width: 620px) {
  .flow { grid-template-columns: minmax(0, 1fr); }
  .feats { grid-template-columns: minmax(0, 1fr); }
  .shots { grid-template-columns: minmax(0, 1fr); gap: 22px; }
  .hero__cta .btn { flex: 1 1 auto; }
  .spec__row { grid-template-columns: 76px 1fr; gap: 12px; }
  .lb { width: 96vw; }
}