/* ============================================================
   DARTA 官网 · 共享样式（base + 组件 + 区块）
   依赖 tokens.css。三页共用，勿在页面内复制样式。
   目录：1 base ｜ 2 布局 ｜ 3 导航 ｜ 4 按钮 ｜ 5 通用区块
        6 Hero ｜ 7 流程图 ｜ 8 卡片/产品 ｜ 9 数据/客户
        10 关于页 ｜ 11 页脚 ｜ 12 弹层 ｜ 13 动效与响应式
   ============================================================ */

/* ---------- 1 base ---------- */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  background: var(--color-page);
  color: var(--color-ink);
  font-family: var(--font-sans);
  font-size: var(--text-body);
  line-height: var(--leading-body);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
img, svg { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
ul { list-style: none; }
h1, h2, h3, h4 { line-height: var(--leading-tight); font-weight: 700; letter-spacing: -.01em; }
strong { font-weight: 700; color: var(--color-ink); }

:focus-visible {
  outline: 2px solid var(--color-deep-navy);
  outline-offset: 3px;
  border-radius: 4px;
}
.skip-link {
  position: absolute; left: -9999px; top: 8px; z-index: 200;
  background: var(--color-deep-navy); color: #fff;
  padding: 10px 18px; border-radius: var(--radius-sm);
}
.skip-link:focus { left: 16px; }

/* ---------- 2 布局 ---------- */
.wrap { max-width: var(--container); margin: 0 auto; padding: 0 var(--pad-x); }
.section { padding: var(--section-y) 0; }
.section--tight { padding: clamp(56px, 6vw, 88px) 0; }
.section--surface { background: var(--color-surface); border-top: 1px solid var(--color-line-soft); border-bottom: 1px solid var(--color-line-soft); }
.section--dark { background: var(--color-deep-navy); color: rgba(255,255,255,.92); }
.section--dark h2, .section--dark h3 { color: #fff; }

.eyebrow {
  font-size: var(--text-micro);
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--color-label);
  font-weight: 600;
  margin-bottom: 14px;
}
.section--dark .eyebrow { color: rgba(255,255,255,.68); }
.section-head { max-width: 760px; margin-bottom: clamp(40px, 5vw, 64px); }
.section-head h2 { font-size: var(--text-h2); }
.section-head p { margin-top: 16px; color: var(--color-muted); max-width: var(--measure); }
.section--dark .section-head p { color: rgba(255,255,255,.82); }

/* ---------- 3 导航 ---------- */
.site-nav {
  position: sticky; top: 0; z-index: 60;
  background: rgba(248,250,251,.88);
  backdrop-filter: saturate(180%) blur(12px);
  -webkit-backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--color-line-soft);
}
.site-nav__in { height: var(--nav-h); display: flex; align-items: center; justify-content: space-between; gap: 24px; }
.site-nav__logo img { height: 34px; width: auto; }
.site-nav__links { display: flex; align-items: center; gap: 32px; }
.site-nav__links a { font-size: 15px; color: var(--color-graphite); transition: color .18s; }
.site-nav__links a:hover { color: var(--color-ink); }
.site-nav__links a[aria-current="page"] { color: var(--color-ink); font-weight: 600; }

/* ---------- 4 按钮 ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  font-size: 15px; font-weight: 600; line-height: 1;
  padding: 14px 26px; border-radius: var(--radius-sm);
  border: 1px solid transparent; cursor: pointer;
  font-family: inherit;
  transition: background .18s, border-color .18s, color .18s, transform .18s;
}
.btn--primary { background: var(--color-deep-navy); color: #fff; }
.btn--primary:hover { background: #1b242c; transform: translateY(-1px); }
.btn--ghost { background: transparent; color: var(--color-graphite); border-color: var(--color-line); }
.btn--ghost:hover { border-color: var(--color-graphite); color: var(--color-ink); }
.btn--onDark { background: #fff; color: var(--color-deep-navy); }
.btn--onDark:hover { background: rgba(255,255,255,.9); transform: translateY(-1px); }
.btn--ghostDark { background: transparent; color: #fff; border-color: rgba(255,255,255,.32); }
.btn--ghostDark:hover { border-color: #fff; }
.btn--sm { padding: 10px 18px; font-size: 14px; }
.btn-row { display: flex; flex-wrap: wrap; gap: 12px; }

.link-arrow { font-size: 15px; font-weight: 600; color: var(--color-graphite); display: inline-flex; gap: 6px; align-items: center; }
.link-arrow::after { content: "→"; transition: transform .18s; }
.link-arrow:hover { color: var(--color-ink); }
.link-arrow:hover::after { transform: translateX(3px); }

/* ---------- 5 通用卡片 ---------- */
.card {
  background: var(--color-surface);
  border: 1px solid var(--color-line-soft);
  border-radius: var(--radius-md);
  padding: 30px 28px;
  box-shadow: var(--shadow-card);
}
.grid { display: grid; gap: 20px; }
.grid--3 { grid-template-columns: repeat(3, 1fr); }
.grid--2 { grid-template-columns: repeat(2, 1fr); }

/* ---------- 6 Hero ---------- */
.hero { position: relative; overflow: hidden; padding: clamp(56px, 6vw, 88px) 0 clamp(64px, 7vw, 104px); }
.hero__grid { display: grid; grid-template-columns: minmax(0, 1.12fr) minmax(0, .88fr); gap: clamp(32px, 4vw, 60px); align-items: center; }
.hero__company { font-size: var(--text-small); color: var(--color-label); letter-spacing: .04em; margin-bottom: 18px; }
/* 中文标语较长，用 h1 档而非 display 档，避免尾字孤行 */
.hero h1 { font-size: clamp(31px, 3.5vw, 52px); letter-spacing: -.015em; }
/* 主张句：位于标语 H1 之下、正文之上，不与 H1 抢层级 */
.hero__claim { margin-top: 20px; font-size: 19px; font-weight: 600; color: var(--color-deep-navy); letter-spacing: .01em; }
.hero__lead { margin-top: 14px; font-size: 17px; color: var(--color-graphite); max-width: var(--measure); }
.hero .btn-row { margin-top: 34px; }
.hero__contact { margin-top: 18px; font-size: var(--text-small); color: var(--color-muted); }
.hero__contact a { border-bottom: 1px solid var(--color-line); }
.hero__contact a:hover { border-color: var(--color-graphite); color: var(--color-ink); }
.hero__trust {
  margin-top: 32px; padding-top: 22px; border-top: 1px solid var(--color-line-soft);
  font-size: var(--text-small); color: var(--color-graphite); letter-spacing: .01em;
}
.hero__trust b { font-weight: 700; color: var(--color-ink); font-variant-numeric: tabular-nums; }
.hero__mark {
  position: absolute; right: -10%; top: -12%; width: 34%; max-width: 440px;
  opacity: .016; pointer-events: none; user-select: none;
}

/* ---------- 7 流程图（数据源 → 探针 → 结构化 → 经营） ---------- */
.flow {
  background: var(--color-surface);
  border: 1px solid var(--color-line-soft);
  border-radius: var(--radius-lg);
  padding: 28px 26px;
  box-shadow: var(--shadow-soft);
}
.flow__title { font-size: var(--text-micro); letter-spacing: .14em; text-transform: uppercase; color: var(--color-label); font-weight: 600; margin-bottom: 20px; }
.flow__stage + .flow__stage { margin-top: 10px; }
.flow__label { font-size: var(--text-micro); color: var(--color-label); letter-spacing: .08em; margin-bottom: 8px; }
.flow__chips { display: flex; flex-wrap: wrap; gap: 8px; }
.chip {
  font-size: 13px; line-height: 1.4;
  padding: 8px 12px; border-radius: 8px;
  border: 1px solid var(--color-line); color: var(--color-graphite);
  background: var(--color-page);
}
.chip--solid { background: var(--color-deep-navy); border-color: var(--color-deep-navy); color: #fff; font-weight: 600; }
.chip--out { border-style: dashed; }
.flow__arrow { display: flex; align-items: center; gap: 10px; color: var(--color-line); margin: 12px 0 12px 2px; }
.flow__arrow::before { content: ""; width: 1px; height: 22px; background: var(--color-line); display: block; margin-left: 9px; }
.flow__arrow span { font-size: var(--text-micro); color: var(--color-label); }
.flow__note { margin-top: 20px; padding-top: 16px; border-top: 1px dashed var(--color-line); font-size: 13px; color: var(--color-muted); }

/* ---------- 8 问题 / 方法 / 产品 ---------- */
.problem { display: grid; grid-template-columns: repeat(3, 1fr); gap: clamp(24px, 3vw, 40px); }
.problem__item { padding-top: 22px; border-top: 2px solid var(--color-graphite); }
.problem__item h3 { font-size: var(--text-h3); margin-bottom: 12px; }
.problem__item p { color: var(--color-muted); font-size: 15.5px; }

.way { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.way__item h3 { font-size: 17px; margin-bottom: 8px; color: #fff; }
.way__item p { font-size: 15px; color: rgba(255,255,255,.82); }
.way__num { font-size: var(--text-micro); letter-spacing: .16em; color: rgba(255,255,255,.6); margin-bottom: 14px; font-weight: 600; }
.way__result { margin-top: clamp(36px, 4vw, 56px); padding-top: 28px; border-top: 1px solid rgba(255,255,255,.14); font-size: 18px; color: #fff; max-width: var(--measure); }

.product { display: flex; flex-direction: column; }
.product__code { font-size: 13px; font-weight: 700; letter-spacing: .16em; color: var(--color-label); }
.product h3 { font-size: 22px; margin: 8px 0 12px; }
.product p { color: var(--color-muted); font-size: 15.5px; flex: 1; }
.product .link-arrow { margin-top: 20px; align-self: flex-start; }
.status {
  display: inline-block; font-size: var(--text-micro); font-weight: 600;
  padding: 5px 10px; border-radius: 999px; letter-spacing: .02em;
}
.status--live { background: var(--color-deep-navy); color: #fff; }
.status--soon { background: transparent; color: var(--color-label); border: 1px solid var(--color-line); }
.product__head { display: flex; align-items: center; justify-content: space-between; gap: 12px; }

/* ---------- 8a 产品证据位（真实脱敏截图槽位） ----------
   未提供真实截图前，槽位内为结构化能力示意，并强制带「能力示意」角标。
   替换方式：把 .shot__body 内容整体换成 <img src="..." alt="...">，并删除角标。 */
.shot {
  position: relative; margin: 0;
  border: 1px solid var(--color-line); border-radius: var(--radius-md);
  background: var(--color-surface); overflow: hidden;
}
.shot__bar {
  display: flex; align-items: center; justify-content: space-between; gap: 12px;
  padding: 10px 14px; border-bottom: 1px solid var(--color-line-soft);
  background: var(--color-page);
}
.shot__name { font-size: var(--text-micro); letter-spacing: .1em; color: var(--color-label); font-weight: 600; }
.shot__badge {
  font-size: 11px; font-weight: 600; letter-spacing: .06em;
  padding: 3px 9px; border-radius: 999px;
  background: rgba(38,49,58,.08); color: var(--color-graphite);
}
.shot__body { padding: 18px 16px; }
.shot__cap { padding: 0 14px 12px; font-size: 12px; color: var(--color-muted); }
/* 示意用的抽象作业行 */
.shotrow { display: grid; grid-template-columns: 22px minmax(0,1fr) auto; gap: 10px; align-items: center;
  padding: 9px 10px; border: 1px solid var(--color-line-soft); border-radius: 8px; background: var(--color-page); }
.shotrow + .shotrow { margin-top: 8px; }
.shotrow__i { width: 22px; height: 22px; border-radius: 6px; background: var(--color-deep-navy); color: #fff;
  font-size: 11px; font-weight: 700; display: flex; align-items: center; justify-content: center; }
.shotrow__t { font-size: 13.5px; color: var(--color-graphite); }
.shotrow__s { font-size: 11.5px; font-weight: 600; padding: 3px 8px; border-radius: 999px;
  background: rgba(38,49,58,.06); color: var(--color-label); white-space: nowrap; }
.shotrow__s--ok { background: rgba(38,49,58,.9); color: #fff; }

/* ---------- 8c 产品层级：UP 主推位 + 次级两卡 ---------- */
.product-layout { display: grid; grid-template-columns: minmax(0, 1.62fr) minmax(0, 1fr); gap: 20px; align-items: start; }
.product--featured { grid-row: 1 / span 2; padding: 34px 34px 30px; border-color: var(--color-line); }
.product--featured h3 { font-size: 28px; margin: 10px 0 12px; }
.product--featured > p { font-size: 16.5px; color: var(--color-graphite); }
.product--featured .shot { margin: 22px 0 20px; }
.product--minor { padding: 24px 26px; }
.product--minor h3 { font-size: 19px; margin: 6px 0 10px; }
.product--minor p { font-size: 14.5px; }
.feature-list { margin: 16px 0 4px; display: grid; gap: 8px; }
.feature-list li { position: relative; padding-left: 18px; font-size: 15px; color: var(--color-graphite); }
.feature-list li::before { content: ""; position: absolute; left: 0; top: 11px; width: 6px; height: 6px; border-radius: 50%; background: var(--color-deep-navy); }

/* ---------- 8b 产品页专用（产品层配色，仅限产品内容语境） ---------- */
.section--paper { background: var(--color-paper); border-top: 1px solid #EFE9DF; border-bottom: 1px solid #EFE9DF; }
.section--paper .eyebrow { color: #A08A5F; }

/* 三步 */
.steps { display: grid; gap: 18px; }
.step {
  display: grid; grid-template-columns: 116px minmax(0, 1fr) minmax(0, 1fr);
  gap: clamp(20px, 3vw, 44px); align-items: start;
  background: var(--color-surface); border: 1px solid var(--color-line-soft);
  border-radius: var(--radius-md); padding: 30px 32px;
}
.step__code { font-size: 13px; font-weight: 700; letter-spacing: .14em; color: var(--color-product-gold); }
.step__no { font-size: var(--text-micro); color: var(--color-muted); margin-top: 6px; letter-spacing: .06em; }
.step h3 { font-size: var(--text-h3); margin-bottom: 8px; }
.step__slogan { font-size: 16px; font-weight: 600; color: var(--color-product-navy); margin-bottom: 10px; }
.step p { color: var(--color-muted); font-size: 15.5px; }
.step__list { margin-top: 14px; }
.step__list li { position: relative; padding: 7px 0 7px 18px; font-size: 15px; color: var(--color-graphite); border-top: 1px dashed var(--color-line); }
.step__list li::before { content: ""; position: absolute; left: 0; top: 16px; width: 6px; height: 6px; border-radius: 50%; background: var(--color-product-gold); }
.step__hook { margin-top: 16px; font-size: 14px; color: var(--color-product-navy); border-left: 3px solid var(--color-product-gold); padding-left: 12px; font-weight: 600; }

/* 路线图 */
.roadmap { display: grid; grid-template-columns: repeat(2, 1fr); gap: 20px; }
.roadmap__item { background: var(--color-surface); border: 1px solid var(--color-line-soft); border-radius: var(--radius-md); padding: 30px 28px; }
.roadmap__item h3 { font-size: 22px; margin: 10px 0 12px; }
.roadmap__item p { color: var(--color-muted); font-size: 15.5px; }
.roadmap__status { margin-top: 18px; padding-top: 16px; border-top: 1px solid var(--color-line-soft); font-size: 14px; color: var(--color-graphite); }

/* ---------- 8d 首个产品引导块（仅介绍身份 + 导流，不展开模块） ---------- */
.first-product {
  background: var(--color-surface); border: 1px solid var(--color-line-soft);
  border-radius: var(--radius-lg); padding: clamp(36px, 5vw, 64px);
  max-width: 860px; box-shadow: var(--shadow-card);
}
.first-product h2 { font-size: clamp(30px, 3.2vw, 42px); letter-spacing: .02em; }
.first-product__sub { margin-top: 6px; font-size: 17px; font-weight: 600; color: var(--color-product-gold); letter-spacing: .04em; }
.first-product__body { margin: 20px 0 30px; font-size: 16.5px; color: var(--color-graphite); max-width: 40em; }

/* ---------- 9 数据与客户 ---------- */
.stats--4 { grid-template-columns: repeat(4, 1fr); }
.section--dark .stat__num { color: #fff; }
.section--dark .stat__label { color: rgba(255,255,255,.66); }
.source-note { margin-top: 28px; font-size: 13px; color: rgba(255,255,255,.66); }
.stats { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.stat__num { font-size: clamp(34px, 3.6vw, 48px); font-weight: 700; letter-spacing: -.02em; font-variant-numeric: tabular-nums; }
.stat__label { margin-top: 6px; color: var(--color-muted); font-size: 15px; }
.clients { margin-top: clamp(32px, 4vw, 48px); padding-top: 26px; border-top: 1px solid var(--color-line-soft); }
.clients__label { font-size: var(--text-small); color: var(--color-muted); margin-bottom: 10px; }
.clients__list { font-size: 17px; font-weight: 600; color: var(--color-graphite); line-height: 2; }

/* ---------- 10 关于页 ---------- */
.about-grid { display: grid; grid-template-columns: minmax(0, 1.5fr) minmax(0, 1fr); gap: clamp(32px, 5vw, 72px); align-items: start; }
.prose p { margin-bottom: 26px; color: var(--color-graphite); max-width: 33em; }
/* 关键句：靠字色与左侧细线强调，不用大面积加粗 */
.prose .prose-key {
  color: var(--color-ink); font-size: 17.5px; font-weight: 600;
  border-left: 3px solid var(--color-deep-navy); padding-left: 16px;
  margin: 30px 0; max-width: 32em;
}
.prose .prose-key--end { border-left-color: var(--color-product-gold); }
.prose p:last-child { margin-bottom: 0; }
.prose .lead { font-size: 19px; color: var(--color-ink); }
/* 叙事内的小标题：语义用 h2（保持层级连续），视觉按 h3 尺寸 */
.prose h2, .prose h3 { font-size: var(--text-h3); margin: 34px 0 12px; color: var(--color-ink); }
.factcard { position: sticky; top: calc(var(--nav-h) + 24px); background: var(--color-surface); border: 1px solid var(--color-line-soft); border-radius: var(--radius-md); overflow: hidden; }
.factcard__row { display: grid; grid-template-columns: 92px 1fr; gap: 14px; padding: 16px 22px; border-bottom: 1px solid var(--color-line-soft); }
.factcard__row:last-child { border-bottom: 0; }
.factcard__k { font-size: 13px; color: var(--color-muted); }
.factcard__v { font-size: 15px; font-weight: 600; }
.zhiyu-quote { margin-top: 28px; text-align: center; letter-spacing: .5em; font-weight: 600; color: var(--color-product-navy); text-indent: .5em; }

/* 联系区 */
.contact-grid { display: grid; grid-template-columns: 240px 1fr 1fr; gap: 20px; align-items: start; }
.qr { text-align: center; }
.qr img { width: 168px; height: 168px; margin: 12px auto 0; background: #fff; }
.qr__fallback { display: none; font-size: 13px; color: var(--color-muted); padding: 24px 12px; border: 1px dashed var(--color-line); border-radius: var(--radius-sm); margin-top: 12px; }

/* ---------- 11 页脚 ---------- */
.site-foot { background: var(--color-deep-navy); color: rgba(255,255,255,.78); padding: clamp(48px, 5vw, 72px) 0 40px; font-size: var(--text-small); }
.site-foot__top { display: grid; grid-template-columns: minmax(0, 1.6fr) repeat(2, minmax(0, 1fr)); gap: 32px; padding-bottom: 32px; border-bottom: 1px solid rgba(255,255,255,.12); }
.site-foot__name { color: #fff; font-size: 16px; font-weight: 600; margin-bottom: 10px; }
.site-foot__desc { max-width: 30em; }
.site-foot h4 { font-size: 13px; color: rgba(255,255,255,.6); font-weight: 600; letter-spacing: .12em; text-transform: uppercase; margin-bottom: 14px; }
.site-foot li { margin-bottom: 9px; }
.site-foot a:hover { color: #fff; }
.site-foot__bottom { padding-top: 26px; display: flex; flex-wrap: wrap; gap: 8px 24px; justify-content: space-between; color: rgba(255,255,255,.66); font-size: 13px; }

/* ---------- 12 弹层 ---------- */
.modal[hidden] { display: none !important; }
.modal {
  position: fixed; inset: 0; z-index: 100;
  display: flex; align-items: center; justify-content: center; padding: 24px;
  background: rgba(23,33,43,.55);
}
.modal__panel {
  background: var(--color-surface); border-radius: var(--radius-md);
  padding: 32px 34px; text-align: center; max-width: 340px; width: 100%;
  box-shadow: var(--shadow-soft); position: relative;
}
.modal__panel h2 { font-size: 19px; margin-bottom: 6px; }
.modal__panel p { font-size: 14px; color: var(--color-muted); }
.modal__panel img { width: 208px; height: 208px; margin: 18px auto; background: #fff; }
.modal__close {
  position: absolute; top: 10px; right: 10px; width: 34px; height: 34px;
  border: 0; background: transparent; color: var(--color-muted);
  font-size: 22px; line-height: 1; cursor: pointer; border-radius: 8px;
}
.modal__close:hover { background: var(--color-page); color: var(--color-ink); }

/* ---------- 13 动效与响应式 ---------- */
.reveal { opacity: 0; transform: translateY(14px); transition: opacity .6s var(--ease), transform .6s var(--ease); }
.reveal.is-in { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: .001ms !important; transition-duration: .001ms !important; }
  .reveal { opacity: 1; transform: none; }
}

@media (max-width: 1024px) {
  .hero__grid { grid-template-columns: 1fr; }
  .hero__mark { display: none; }
  .contact-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 960px) {
  .step { grid-template-columns: 100px minmax(0, 1fr); }
  .step > div:last-child { grid-column: 1 / -1; }
  .stats--4 { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 960px) {
  .product-layout { grid-template-columns: 1fr; }
  .product--featured { grid-row: auto; padding: 28px 26px; }
}
@media (max-width: 860px) {
  .grid--3, .problem, .way, .stats { grid-template-columns: 1fr; }
  .about-grid { grid-template-columns: 1fr; }
  .factcard { position: static; order: -1; margin-bottom: 8px; }
  .site-foot__top { grid-template-columns: 1fr; gap: 26px; }
  .roadmap { grid-template-columns: 1fr; }
}
@media (max-width: 560px) {
  .step { grid-template-columns: 1fr; gap: 16px; padding: 26px 22px; }
  .step > div:last-child { grid-column: auto; }
  .stats--4 { grid-template-columns: 1fr; }
}
@media (max-width: 640px) {
  /* 「了解智隅 ↗」是全站唯一 CTA，移动端必须保留（不再隐藏） */
  .site-nav__in { gap: 10px; }
  .site-nav__links { gap: 14px; }
  .site-nav__links a { font-size: 13.5px; }
  .site-nav__links .btn { padding: 8px 12px; font-size: 13px; white-space: nowrap; }
  .site-nav__logo img { height: 26px; }
  .grid--2, .contact-grid { grid-template-columns: 1fr; }
  .btn-row .btn { flex: 1 1 100%; }
  .factcard__row { grid-template-columns: 80px 1fr; padding: 14px 18px; }
}