/* ============================================================
   ag真人 - 全站样式表
   Human + AI Marketing Advisor Design System
   深石墨 / 商务深蓝 / 数据青 / 冷白 / 暖橙 / 紫色
   ============================================================ */

:root {
  --c-graphite: #22262d;
  --c-navy: #16305c;
  --c-navy-deep: #0d1f3d;
  --c-cyan: #0d7d8c;
  --c-cyan-light: #e4f4f4;
  --c-white: #f6f7f9;
  --c-paper: #ffffff;
  --c-orange: #d9772f;
  --c-purple: #6c4a95;
  --c-border: #dfe3e8;
  --c-text: #2a2f37;
  --c-text-soft: #5a6270;
  --c-text-faint: #838b98;
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --shadow-card: 0 2px 10px rgba(22, 48, 92, 0.08);
  --shadow-card-hover: 0 8px 24px rgba(22, 48, 92, 0.14);
  --max-width: 1180px;
  --font-base: "Microsoft YaHei", "PingFang SC", "Hiragino Sans GB", "Segoe UI", Arial, sans-serif;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--font-base);
  color: var(--c-text);
  background: var(--c-white);
  line-height: 1.75;
  font-size: 16px;
  overflow-x: hidden;
}

img { max-width: 100%; height: auto; display: block; }

a { color: var(--c-navy); text-decoration: none; }
a:hover { color: var(--c-cyan); }

h1, h2, h3, h4 { color: var(--c-navy-deep); line-height: 1.4; margin: 0 0 .6em; }
p { margin: 0 0 1em; }

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 20px;
}

.visually-hidden {
  position: absolute;
  width: 1px; height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
}

/* ---------------- Header / Nav ---------------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--c-navy-deep);
  border-bottom: 1px solid rgba(255,255,255,.08);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 12px 20px;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: #fff;
  font-size: 18px;
  font-weight: 700;
  letter-spacing: .5px;
}

.nav-brand img { width: 34px; height: 34px; }

.nav-toggle {
  display: none;
  background: none;
  border: 1px solid rgba(255,255,255,.35);
  border-radius: var(--radius-sm);
  color: #fff;
  font-size: 20px;
  padding: 4px 10px;
  cursor: pointer;
}

.nav-list {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-list a {
  display: block;
  color: rgba(255,255,255,.82);
  font-size: 14.5px;
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  white-space: nowrap;
}

.nav-list a:hover,
.nav-list a[aria-current="page"] {
  background: rgba(255,255,255,.12);
  color: #fff;
}

/* ---------------- Breadcrumb ---------------- */
.breadcrumb {
  font-size: 13px;
  color: var(--c-text-faint);
  padding: 14px 0;
}
.breadcrumb a { color: var(--c-text-soft); }
.breadcrumb .sep { margin: 0 6px; }

/* ---------------- Hero ---------------- */
.hero {
  background: linear-gradient(135deg, var(--c-navy-deep) 0%, var(--c-navy) 55%, var(--c-cyan) 130%);
  color: #fff;
  padding: 52px 0 64px;
}

.hero-inner {
  display: flex;
  align-items: center;
  gap: 40px;
  flex-wrap: wrap;
}

.hero-text { flex: 1 1 420px; }
.hero-visual { flex: 1 1 380px; min-width: 280px; }

.hero h1 {
  color: #fff;
  font-size: 30px;
  margin-bottom: .5em;
}

.hero .lead {
  color: rgba(255,255,255,.88);
  font-size: 17px;
  max-width: 640px;
}

.hero-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 18px;
}

.hero-tags span {
  background: rgba(255,255,255,.14);
  border: 1px solid rgba(255,255,255,.22);
  color: #fff;
  font-size: 12.5px;
  padding: 5px 12px;
  border-radius: 999px;
}

/* ---------------- Section generic ---------------- */
.section {
  padding: 48px 0;
  border-bottom: 1px solid var(--c-border);
}

.section-alt { background: var(--c-paper); }

.section-head { max-width: 780px; margin: 0 auto 32px; text-align: left; }
.section-head.center { text-align: center; margin-left: auto; margin-right: auto; }

.section-title {
  font-size: 24px;
  position: relative;
  padding-left: 14px;
  border-left: 5px solid var(--c-cyan);
}

.section-kicker {
  color: var(--c-cyan);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 1px;
  text-transform: uppercase;
  margin-bottom: 6px;
  display: block;
}

.section-lead { color: var(--c-text-soft); font-size: 15.5px; }

/* ---------------- Architecture / structure blocks ---------------- */
.arch-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}

.arch-card {
  background: var(--c-paper);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-lg);
  padding: 24px;
  box-shadow: var(--shadow-card);
}

.arch-card.human { border-top: 4px solid var(--c-orange); }
.arch-card.ai { border-top: 4px solid var(--c-cyan); }

.arch-card h3 { font-size: 18px; display: flex; align-items: center; gap: 8px; }
.arch-card ul { margin: 0; padding-left: 20px; color: var(--c-text-soft); font-size: 14.5px; }
.arch-card li { margin-bottom: 6px; }

/* ---------------- Cards / grid ---------------- */
.card-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
}

.card {
  background: var(--c-paper);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-lg);
  padding: 22px;
  box-shadow: var(--shadow-card);
  transition: box-shadow .2s ease, transform .2s ease;
  display: flex;
  flex-direction: column;
}

.card:hover { box-shadow: var(--shadow-card-hover); transform: translateY(-2px); }

.card .card-tag {
  color: var(--c-cyan);
  font-size: 12.5px;
  font-weight: 700;
  margin-bottom: 8px;
}

.card h3 { font-size: 16.5px; margin-bottom: 10px; }
.card p { color: var(--c-text-soft); font-size: 14px; flex: 1; }
.card .card-link { font-size: 13.5px; font-weight: 700; margin-top: 10px; }

/* ---------------- Long-form article ---------------- */
.article {
  background: var(--c-paper);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-lg);
  padding: 30px clamp(18px, 4vw, 40px);
  margin-bottom: 30px;
  box-shadow: var(--shadow-card);
}

.article-eyebrow {
  color: var(--c-orange);
  font-size: 12.5px;
  font-weight: 700;
  letter-spacing: 1px;
  text-transform: uppercase;
  margin-bottom: 8px;
  display: block;
}

.article h2, .article h3.article-title {
  font-size: 22px;
  margin-bottom: .5em;
}

.article-meta {
  color: var(--c-text-faint);
  font-size: 13px;
  margin-bottom: 18px;
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
}

.article-body p { color: var(--c-text); font-size: 15.5px; }
.article-body strong { color: var(--c-navy-deep); }

.pull-quote {
  border-left: 4px solid var(--c-orange);
  background: var(--c-cyan-light);
  padding: 14px 18px;
  margin: 20px 0;
  font-size: 15px;
  color: var(--c-navy-deep);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}

/* ---------------- Observation cards (官网观察) ---------------- */
.observation-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.observation {
  background: var(--c-navy-deep);
  color: rgba(255,255,255,.92);
  border-radius: var(--radius-lg);
  padding: 24px;
}

.observation .card-tag { color: var(--c-cyan-light); }
.observation h3 { color: #fff; font-size: 16.5px; }
.observation p { color: rgba(255,255,255,.78); font-size: 14px; }

/* ---------------- Summary grid (二级页面摘要回流) ---------------- */
.summary-list { display: flex; flex-direction: column; gap: 14px; }

.summary-item {
  display: flex;
  gap: 16px;
  background: var(--c-paper);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-md);
  padding: 16px 18px;
}

.summary-item .num {
  flex: 0 0 auto;
  width: 34px; height: 34px;
  border-radius: 50%;
  background: var(--c-cyan-light);
  color: var(--c-cyan);
  font-weight: 700;
  display: flex; align-items: center; justify-content: center;
  font-size: 14px;
}

.summary-item h4 { font-size: 15.5px; margin-bottom: 4px; }
.summary-item p { font-size: 13.8px; color: var(--c-text-soft); margin-bottom: 0; }

.summary-more { text-align: right; margin-top: 14px; }

/* ---------------- Funnel diagrams ---------------- */
.funnel {
  display: flex;
  align-items: stretch;
  gap: 10px;
  flex-wrap: wrap;
}

.funnel-step {
  flex: 1 1 110px;
  background: var(--c-paper);
  border: 1px solid var(--c-border);
  border-top: 4px solid var(--c-cyan);
  border-radius: var(--radius-md);
  padding: 14px 10px;
  text-align: center;
  font-size: 13.5px;
  color: var(--c-navy-deep);
  font-weight: 700;
}

.funnel-step small {
  display: block;
  font-weight: 400;
  color: var(--c-text-soft);
  margin-top: 4px;
  font-size: 12px;
}

.funnel-arrow {
  display: flex;
  align-items: center;
  color: var(--c-text-faint);
  font-size: 18px;
}

.funnel-tabs {
  display: flex;
  gap: 8px;
  margin-bottom: 18px;
  flex-wrap: wrap;
}

.funnel-tab {
  background: var(--c-paper);
  border: 1px solid var(--c-border);
  border-radius: 999px;
  padding: 7px 16px;
  font-size: 13.5px;
  cursor: pointer;
  color: var(--c-text-soft);
}

.funnel-tab[aria-selected="true"] {
  background: var(--c-navy);
  border-color: var(--c-navy);
  color: #fff;
}

.funnel-panel { display: none; }
.funnel-panel.is-active { display: block; }

/* ---------------- FAQ ---------------- */
.faq-list { display: flex; flex-direction: column; gap: 10px; }

.faq-item {
  background: var(--c-paper);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.faq-question {
  width: 100%;
  text-align: left;
  background: none;
  border: none;
  padding: 15px 18px;
  font-size: 15px;
  font-weight: 700;
  color: var(--c-navy-deep);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  cursor: pointer;
  font-family: inherit;
}

.faq-question .icon {
  flex: 0 0 auto;
  color: var(--c-cyan);
  font-size: 18px;
  transition: transform .2s ease;
}

.faq-item[data-open="true"] .icon { transform: rotate(45deg); }

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height .25s ease;
  padding: 0 18px;
  color: var(--c-text-soft);
  font-size: 14.5px;
}

.faq-item[data-open="true"] .faq-answer {
  padding: 0 18px 16px;
}

/* ---------------- Company intro ---------------- */
.company-intro {
  background: var(--c-paper);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-lg);
  padding: 30px clamp(18px, 4vw, 40px);
}

/* ---------------- Disclaimer ---------------- */
.disclaimer {
  font-size: 13px;
  color: var(--c-text-faint);
  background: #eef1f5;
  border-radius: var(--radius-md);
  padding: 16px 20px;
}

/* ---------------- App feature list ---------------- */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}

.feature-item {
  background: var(--c-paper);
  border: 1px solid var(--c-border);
  border-radius: var(--radius-md);
  padding: 18px 14px;
  text-align: center;
}

.feature-item .idx {
  color: var(--c-cyan);
  font-weight: 700;
  font-size: 13px;
  margin-bottom: 6px;
  display: block;
}

.feature-item h4 { font-size: 14.5px; margin-bottom: 4px; }
.feature-item p { font-size: 12.8px; color: var(--c-text-soft); margin: 0; }

.install-note {
  background: var(--c-cyan-light);
  border: 1px dashed var(--c-cyan);
  border-radius: var(--radius-md);
  padding: 16px 20px;
  font-size: 14px;
  color: var(--c-navy-deep);
}

/* ---------------- Compare table -> card fallback on mobile ---------------- */
.table-wrap { overflow-x: auto; }
table.compare {
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
  min-width: 560px;
}
table.compare th, table.compare td {
  border: 1px solid var(--c-border);
  padding: 10px 12px;
  text-align: left;
}
table.compare th { background: var(--c-navy-deep); color: #fff; }
table.compare tr:nth-child(even) td { background: #fbfcfd; }

/* ---------------- CTA ---------------- */
.cta-box {
  background: linear-gradient(120deg, var(--c-navy) 0%, var(--c-purple) 100%);
  color: #fff;
  border-radius: var(--radius-lg);
  padding: 30px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 20px;
  flex-wrap: wrap;
}
.cta-box h3 { color: #fff; margin-bottom: 4px; }
.cta-box p { color: rgba(255,255,255,.82); margin: 0; }
.cta-btn {
  background: var(--c-orange);
  color: #fff;
  padding: 12px 26px;
  border-radius: 999px;
  font-weight: 700;
  font-size: 14.5px;
  white-space: nowrap;
}
.cta-btn:hover { background: #c2661f; color: #fff; }

/* ---------------- Footer ---------------- */
.site-footer {
  background: var(--c-navy-deep);
  color: rgba(255,255,255,.75);
  padding: 40px 0 20px;
  font-size: 13.5px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1.4fr;
  gap: 26px;
  margin-bottom: 24px;
}

.footer-grid h4 { color: #fff; font-size: 14.5px; margin-bottom: 12px; }
.footer-grid ul { list-style: none; margin: 0; padding: 0; }
.footer-grid li { margin-bottom: 8px; }
.footer-grid a { color: rgba(255,255,255,.72); }
.footer-grid a:hover { color: #fff; }

.footer-brand img { width: 30px; height: 30px; margin-bottom: 8px; }
.footer-disclaimer {
  border-top: 1px solid rgba(255,255,255,.12);
  padding-top: 16px;
  font-size: 12px;
  color: rgba(255,255,255,.55);
  line-height: 1.8;
}

.footer-bottom {
  border-top: 1px solid rgba(255,255,255,.12);
  padding-top: 16px;
  font-size: 12px;
  color: rgba(255,255,255,.5);
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 8px;
}

/* ---------------- Back to top ---------------- */
.back-to-top {
  position: fixed;
  right: 20px;
  bottom: 24px;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--c-navy);
  color: #fff;
  border: none;
  font-size: 18px;
  cursor: pointer;
  box-shadow: 0 6px 18px rgba(0,0,0,.25);
  display: none;
  align-items: center;
  justify-content: center;
  z-index: 90;
}
.back-to-top.is-visible { display: flex; }

/* ---------------- Utility ---------------- */
.mt-0 { margin-top: 0; }
.text-center { text-align: center; }

/* ============================================================
   Responsive
   ============================================================ */
@media (max-width: 1024px) {
  .nav-toggle { display: inline-block; }
  .nav-list {
    display: none;
    width: 100%;
    flex-direction: column;
    gap: 2px;
    order: 3;
    margin-top: 10px;
  }
  .nav-list.is-open { display: flex; }
  .nav { flex-wrap: wrap; }
  .card-grid { grid-template-columns: repeat(2, 1fr); }
  .observation-grid { grid-template-columns: repeat(2, 1fr); }
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1.4fr 1fr 1fr; }
  .footer-grid .footer-col-app { grid-column: span 3; }
}

@media (max-width: 768px) {
  .arch-grid { grid-template-columns: 1fr; }
  .hero h1 { font-size: 24px; }
  .card-grid { grid-template-columns: 1fr; }
  .observation-grid { grid-template-columns: 1fr; }
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .footer-grid .footer-col-brand { grid-column: span 2; }
  .footer-grid .footer-col-app { grid-column: span 2; }
  .funnel { flex-direction: column; }
  .funnel-arrow { transform: rotate(90deg); justify-content: center; padding: 2px 0; }
  .summary-item { flex-direction: column; }
}

@media (max-width: 480px) {
  .container { padding: 0 14px; }
  .hero { padding: 36px 0 44px; }
  .section { padding: 34px 0; }
  .section-title { font-size: 20px; }
  .article { padding: 22px 16px; }
  .feature-grid { grid-template-columns: 1fr 1fr; }
  .cta-box { flex-direction: column; align-items: flex-start; }
}