/* ag真人官网 — Human + AI Collaboration Studio 视觉系统 */

:root {
  --bg: #f4f5f7;
  --bg-alt: #ebedf1;
  --surface: #ffffff;
  --surface-soft: #f8f9fb;
  --border: #dde1e8;
  --border-soft: #e8eaf0;
  --text: #1e2126;
  --text-soft: #454b56;
  --text-mute: #6b7280;
  --blue-deep: #16305c;
  --blue-mid: #1f4e8c;
  --purple: #4d4fcf;
  --cyan: #1a8fa6;
  --identity: #9a3b6e;
  --live: #d97a1f;
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 22px;
  --shadow-sm: 0 1px 3px rgba(22, 30, 48, 0.06);
  --shadow-md: 0 8px 28px rgba(22, 30, 48, 0.08);
  --maxw: 1180px;
  --font: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }

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

img { max-width: 100%; display: block; }
a { color: var(--blue-mid); text-decoration: none; }
a:hover { text-decoration: underline; }
h1, h2, h3, h4 { font-weight: 700; line-height: 1.4; color: var(--blue-deep); margin: 0 0 .6em; }
p { margin: 0 0 1em; }
ul, ol { margin: 0 0 1em; padding-left: 1.4em; }

.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }

/* ---------- Skip link ---------- */
.skip-link {
  position: absolute; left: -999px; top: 0; background: var(--blue-deep); color: #fff;
  padding: 10px 16px; z-index: 999; border-radius: 0 0 8px 0;
}
.skip-link:focus { left: 0; }

/* ---------- Top notice bar ---------- */
.notice-bar {
  background: var(--blue-deep); color: #cfd9ec; font-size: 13px; text-align: center;
  padding: 7px 16px;
}
.notice-bar a { color: #fff; text-decoration: underline; }

/* ---------- Header / Nav ---------- */
header.site-header {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  position: sticky; top: 0; z-index: 100;
}
.nav-row {
  display: flex; align-items: center; justify-content: space-between;
  padding: 14px 24px; max-width: var(--maxw); margin: 0 auto;
}
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 18px; color: var(--blue-deep); }
.brand .brand-mark {
  width: 34px; height: 34px; border-radius: 9px;
  background: linear-gradient(135deg, var(--blue-mid), var(--purple));
  display: inline-flex; align-items: center; justify-content: center;
  color: #fff; font-size: 14px; font-weight: 700;
}
.brand small { display: block; font-weight: 400; font-size: 11px; color: var(--text-mute); }

nav.main-nav { display: flex; }
nav.main-nav ul { list-style: none; margin: 0; padding: 0; display: flex; gap: 4px; flex-wrap: wrap; }
nav.main-nav a {
  color: var(--text-soft); font-size: 14.5px; padding: 8px 12px; border-radius: 8px; display: inline-block;
}
nav.main-nav a:hover, nav.main-nav a[aria-current="page"] {
  background: var(--bg-alt); color: var(--blue-deep); text-decoration: none;
}

.nav-toggle {
  display: none; background: none; border: 1px solid var(--border); border-radius: 8px;
  padding: 8px 10px; font-size: 20px; color: var(--blue-deep); cursor: pointer;
}

/* ---------- Hero ---------- */
.hero { padding: 56px 0 40px; }
.hero-grid { display: grid; grid-template-columns: 1.15fr 0.85fr; gap: 44px; align-items: center; }
.hero h1 { font-size: 30px; letter-spacing: -0.01em; }
.hero .lede { font-size: 16px; color: var(--text-soft); }
.hero-tags { display: flex; flex-wrap: wrap; gap: 8px; margin: 18px 0; }
.tag {
  font-size: 12.5px; padding: 5px 11px; border-radius: 999px; background: var(--surface);
  border: 1px solid var(--border); color: var(--text-soft);
}
.tag.identity { color: var(--identity); border-color: #e4c3d5; }
.tag.live { color: var(--live); border-color: #f0d3ac; }
.tag.cyan { color: var(--cyan); border-color: #bfe3ea; }

.cta-row { display: flex; gap: 12px; flex-wrap: wrap; margin-top: 8px; }
.btn {
  display: inline-block; padding: 12px 22px; border-radius: 999px; font-size: 14.5px; font-weight: 600;
  border: 1px solid transparent; cursor: pointer;
}
.btn-primary { background: var(--blue-deep); color: #fff; }
.btn-primary:hover { background: #0f2445; text-decoration: none; }
.btn-ghost { background: var(--surface); color: var(--blue-deep); border-color: var(--border); }
.btn-ghost:hover { border-color: var(--blue-mid); text-decoration: none; }

.hero-art { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-lg); padding: 18px; box-shadow: var(--shadow-md); }
.hero-art figcaption { font-size: 12.5px; color: var(--text-mute); text-align: center; margin-top: 8px; }

/* ---------- Section shell ---------- */
section.block { padding: 46px 0; }
section.block.alt { background: var(--surface); border-top: 1px solid var(--border-soft); border-bottom: 1px solid var(--border-soft); }
.block-head { max-width: 760px; margin: 0 0 30px; }
.eyebrow { text-transform: uppercase; letter-spacing: .08em; font-size: 12px; color: var(--purple); font-weight: 700; margin-bottom: 8px; }
.block-head h2 { font-size: 24px; }
.block-head .desc { color: var(--text-soft); font-size: 15px; }

/* ---------- Pillars (3 lines) ---------- */
.pillars { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.pillar-card {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-md);
  padding: 22px; box-shadow: var(--shadow-sm);
}
.pillar-card .icon-chip {
  width: 40px; height: 40px; border-radius: 10px; display: flex; align-items: center; justify-content: center;
  font-size: 18px; margin-bottom: 12px; color: #fff;
}
.pillar-card.p1 .icon-chip { background: var(--identity); }
.pillar-card.p2 .icon-chip { background: var(--purple); }
.pillar-card.p3 .icon-chip { background: var(--live); }
.pillar-card h3 { font-size: 17px; }
.pillar-card p { color: var(--text-soft); font-size: 14.5px; }
.pillar-card a.more { font-size: 13.5px; font-weight: 600; }

/* ---------- Flow diagram card ---------- */
.flow-card { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-lg); padding: 20px; box-shadow: var(--shadow-sm); }
.flow-card figcaption { font-size: 13px; color: var(--text-mute); margin-top: 10px; }

/* ---------- Callout / disclaimer ---------- */
.callout {
  background: #fbf3f7; border: 1px solid #ecc9de; border-radius: var(--radius-md);
  padding: 18px 20px; font-size: 14.5px; color: #5f2a48;
}
.callout.blue { background: #eef3fb; border-color: #c7d8f0; color: var(--blue-deep); }
.callout.live { background: #fdf3e8; border-color: #f0d3ac; color: #7a4c14; }
.callout strong { color: inherit; }

/* ---------- Article cards & full articles ---------- */
.article-list { display: grid; gap: 22px; }
.article-card {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-md);
  padding: 24px 26px; box-shadow: var(--shadow-sm);
}
.article-card .meta { font-size: 12.5px; color: var(--text-mute); margin-bottom: 8px; display: flex; gap: 10px; flex-wrap: wrap; }
.article-card .meta .cat { color: var(--purple); font-weight: 600; }
.article-card h3 { font-size: 19px; margin-bottom: 10px; }
.article-card .excerpt { color: var(--text-soft); font-size: 14.5px; }

article.full-article {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-lg);
  padding: 30px 32px; box-shadow: var(--shadow-sm); margin-bottom: 26px; scroll-margin-top: 90px;
}
article.full-article h3.art-title { font-size: 21px; }
article.full-article .meta { font-size: 12.5px; color: var(--text-mute); margin-bottom: 14px; display:flex; gap:10px; flex-wrap: wrap; }
article.full-article .meta .cat { color: var(--purple); font-weight: 600; }
article.full-article .struct-tag {
  display: inline-block; font-size: 12px; color: var(--cyan); border: 1px solid #bfe3ea; background: #f1fafb;
  padding: 3px 10px; border-radius: 999px; margin: 4px 0 16px;
}
article.full-article p { color: var(--text-soft); font-size: 15px; }
article.full-article .further-reading {
  margin-top: 18px; padding-top: 16px; border-top: 1px dashed var(--border);
  font-size: 14px;
}
article.full-article .further-reading h4 { font-size: 13.5px; color: var(--text-mute); text-transform: uppercase; letter-spacing: .04em; margin-bottom: 8px;}
article.full-article .further-reading ul { padding-left: 1.1em; }

/* ---------- Secondary flowback cards (compact) ---------- */
.flow-back-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 18px; }
.fb-card { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-md); padding: 18px 20px; }
.fb-card .fb-head { display: flex; justify-content: space-between; align-items: baseline; margin-bottom: 6px; }
.fb-card .fb-head a.hub { font-size: 12.5px; font-weight: 600; }
.fb-card h4 { font-size: 15.5px; margin: 0 0 8px; color: var(--blue-deep); }
.fb-card p { font-size: 13.8px; color: var(--text-soft); margin: 0; }

/* ---------- Trend list ---------- */
.trend-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }
.trend-item { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-md); padding: 18px; }
.trend-item .num { font-size: 12px; color: var(--text-mute); font-weight: 700; }
.trend-item .arrow { font-size: 13.5px; color: var(--purple); font-weight: 700; margin: 4px 0 8px; }
.trend-item p { font-size: 13.8px; color: var(--text-soft); margin: 0; }

/* ---------- FAQ ---------- */
.faq-list { border-top: 1px solid var(--border); }
.faq-item { border-bottom: 1px solid var(--border); }
.faq-q {
  width: 100%; text-align: left; background: none; border: none; padding: 16px 4px; font-size: 15.5px;
  font-weight: 600; color: var(--text); cursor: pointer; display: flex; justify-content: space-between; gap: 12px;
  font-family: inherit;
}
.faq-q .plus { color: var(--purple); font-size: 18px; flex: none; }
.faq-a { display: none; padding: 0 4px 18px; color: var(--text-soft); font-size: 14.5px; }
.faq-item.open .faq-a { display: block; }
.faq-item.open .plus { transform: rotate(45deg); }

/* ---------- Feature grid (app) ---------- */
.feature-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }
.feature-card { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-md); padding: 18px; text-align: left; }
.feature-card .fnum { font-size: 12px; color: var(--purple); font-weight: 700; margin-bottom: 6px; }
.feature-card h4 { font-size: 15px; margin: 0 0 6px; }
.feature-card p { font-size: 13.3px; color: var(--text-soft); margin: 0; }

/* ---------- Table-ish key/value ---------- */
.kv-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 14px; }
.kv-item { background: var(--surface-soft); border: 1px solid var(--border-soft); border-radius: var(--radius-sm); padding: 14px 16px; font-size: 14px; }
.kv-item b { color: var(--blue-deep); }

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

/* ---------- Footer ---------- */
footer.site-footer { background: var(--blue-deep); color: #c8d3e8; padding: 40px 0 24px; margin-top: 20px; }
footer.site-footer .foot-grid { display: grid; grid-template-columns: 1.3fr 1fr 1fr 1fr; gap: 28px; }
footer.site-footer h5 { color: #fff; font-size: 14.5px; margin: 0 0 12px; }
footer.site-footer ul { list-style: none; padding: 0; margin: 0; }
footer.site-footer li { margin-bottom: 8px; font-size: 13.5px; }
footer.site-footer a { color: #c8d3e8; }
footer.site-footer a:hover { color: #fff; }
footer.site-footer .foot-brand { font-weight: 700; color: #fff; font-size: 16px; margin-bottom: 8px; }
footer.site-footer .foot-meta { font-size: 12.5px; color: #93a3c2; margin-top: 4px; }
.foot-bottom { border-top: 1px solid rgba(255,255,255,0.12); margin-top: 28px; padding-top: 18px; font-size: 12.5px; color: #93a3c2; }
.foot-disclaimer { font-size: 12px; color: #8494b6; line-height: 1.7; margin-top: 10px; }

/* ---------- Utility ---------- */
.mt-0 { margin-top: 0; }
.section-links { display:flex; flex-wrap:wrap; gap:10px; margin-top: 10px; }
.section-links a { font-size: 13.5px; background: var(--surface-soft); border:1px solid var(--border-soft); padding:6px 12px; border-radius:999px; }

/* ---------- Responsive ---------- */
@media (max-width: 1024px) {
  .hero-grid { grid-template-columns: 1fr; }
  .pillars { grid-template-columns: repeat(3, 1fr); gap: 14px; }
  .trend-grid { grid-template-columns: repeat(2, 1fr); }
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
  footer.site-footer .foot-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 768px) {
  nav.main-nav { display: none; }
  nav.main-nav.open { display: block; position: absolute; top: 100%; left: 0; right: 0; background: var(--surface); border-bottom: 1px solid var(--border); box-shadow: var(--shadow-md); }
  nav.main-nav.open ul { flex-direction: column; padding: 10px 20px 18px; gap: 2px; }
  .nav-toggle { display: inline-flex; }
  .pillars { grid-template-columns: 1fr; }
  .flow-back-grid { grid-template-columns: 1fr; }
  .kv-grid { grid-template-columns: 1fr; }
  .hero h1 { font-size: 24px; }
  article.full-article { padding: 22px 18px; }
}
@media (max-width: 430px) {
  .wrap { padding: 0 16px; }
  .trend-grid, .feature-grid { grid-template-columns: 1fr; }
  .hero { padding: 36px 0 28px; }
  .article-card { padding: 18px; }
}