/* === 擎天 AI · 高级咨询公司视觉体系 === */

:root {
  --ink: #1a1d20;
  --paper: #f8f6f1;
  --white: #fff;
  --gold: #b8975a;
  --navy: #1e2d3d;
  --green: #2d5a4b;
  --muted: #7d7f82;
  --line: #e2ded7;
  --max: 1160px;
}

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

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  font-size: 16px;
  line-height: 1.75;
  letter-spacing: 0.01em;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; text-decoration: none; }
button, input, textarea { font: inherit; }

/* === Header === */
.site-header {
  height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 max(28px, calc((100vw - var(--max)) / 2));
  border-bottom: 1px solid var(--line);
  position: sticky; top: 0;
  background: rgba(248, 246, 241, 0.94);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  z-index: 20;
}

.brand {
  display: flex; align-items: center; gap: 10px;
  font-weight: 600; font-size: 18px; letter-spacing: 0.02em;
}

.brand-mark {
  width: 36px; height: 36px;
  display: grid; place-items: center;
  background: var(--navy); color: #fff;
  font-size: 17px; font-weight: 700;
  letter-spacing: 0;
}

.site-header nav { display: flex; gap: 32px; font-size: 14px; letter-spacing: 0.03em; }
.site-header nav a { position: relative; padding: 4px 0; }
.site-header nav a::after {
  content: ''; position: absolute; bottom: 0; left: 0;
  width: 0; height: 1px; background: var(--gold);
  transition: width 0.25s ease;
}
.site-header nav a:hover::after { width: 100%; }
.site-header nav a:hover, .text-link:hover, footer a:hover { color: var(--gold); }

/* === Buttons === */
.button {
  display: inline-flex; justify-content: center; align-items: center;
  min-height: 48px; padding: 0 28px;
  background: var(--navy); color: #fff;
  border: 0; cursor: pointer;
  font-weight: 600; font-size: 15px; letter-spacing: 0.03em;
  transition: background 0.2s, transform 0.15s;
}
.button:hover { background: #2a3f52; transform: translateY(-1px); }
.button-small { min-height: 38px; padding: 0 20px; font-size: 13px; }

/* === Hero === */
.hero {
  min-height: calc(100vh - 72px);
  display: grid; grid-template-rows: 1fr auto;
  max-width: var(--max); margin: auto;
  padding: 10vh 28px 0;
}
.hero-inner { max-width: 860px; align-self: center; }

.eyebrow {
  text-transform: uppercase;
  font-size: 12px; font-weight: 600; letter-spacing: 0.12em;
  color: var(--gold); margin: 0 0 28px;
}

.hero h1 {
  font-family: "Noto Serif SC", "Georgia", "Songti SC", serif;
  font-size: clamp(52px, 7.5vw, 100px);
  line-height: 1.06; margin: 0;
  max-width: 900px; font-weight: 700;
  color: var(--navy);
}

.hero-lead {
  font-size: clamp(17px, 1.8vw, 22px);
  line-height: 1.7; max-width: 640px;
  margin: 32px 0; color: var(--muted);
  font-weight: 400;
}

.hero-actions { display: flex; align-items: center; gap: 32px; }

.text-link {
  font-weight: 600; font-size: 15px;
  color: var(--muted);
  transition: color 0.2s;
}
.text-link span { color: var(--gold); }

.hero-signals {
  display: grid; grid-template-columns: repeat(3, 1fr);
  border-top: 1px solid var(--line);
}
.hero-signals div {
  padding: 28px 24px 28px 0;
  display: flex; gap: 18px; align-items: center;
}
.hero-signals div + div { border-left: 1px solid var(--line); padding-left: 24px; }
.hero-signals strong {
  font-family: "Noto Serif SC", Georgia, serif;
  color: var(--gold); font-size: 24px; font-weight: 600;
}
.hero-signals span { font-size: 13px; line-height: 1.55; color: var(--muted); }

/* === Sections === */
.section {
  max-width: var(--max); margin: auto;
  padding: 140px 28px;
}

.section-head { max-width: 740px; margin-bottom: 72px; }
.section-head h2 {
  font-family: "Noto Serif SC", "Georgia", "Songti SC", serif;
  font-size: clamp(38px, 4.8vw, 62px);
  line-height: 1.12; margin: 0 0 20px;
  font-weight: 700; color: var(--navy);
}
.section-head > p:last-child { color: var(--muted); font-size: 17px; }

/* === Problem Band === */
.problem-band {
  background: var(--navy); color: #fff;
  padding: 130px max(28px, calc((100vw - var(--max)) / 2));
}
.section-head.light > p:last-child { color: #a8b4c2; }
.problem-grid {
  display: grid; grid-template-columns: repeat(3, 1fr);
  border-top: 1px solid rgba(255,255,255,0.12);
}
.problem-grid article {
  padding: 40px 36px 28px 0;
  min-height: 340px; display: flex; flex-direction: column;
}
.problem-grid article + article {
  border-left: 1px solid rgba(255,255,255,0.12);
  padding-left: 36px;
}
.problem-grid span {
  color: var(--gold); font-size: 12px; letter-spacing: 0.08em; font-weight: 600;
}
.problem-grid h3 {
  font-family: "Noto Serif SC", Georgia, serif;
  font-size: 48px; margin: 28px 0 14px; font-weight: 600;
}
.problem-grid p { color: #bcc5d0; line-height: 1.7; }
.problem-grid strong { margin-top: auto; color: var(--gold); font-weight: 600; font-size: 14px; }

/* === Q6 Methodology === */
.method-list {
  list-style: none; margin: 0; padding: 0;
  border-top: 1px solid var(--line);
}
.method-list li {
  display: grid; grid-template-columns: 90px 1fr;
  padding: 32px 0; border-bottom: 1px solid var(--line);
  align-items: center;
}
.method-list > li > span {
  font-family: "Noto Serif SC", Georgia, serif;
  font-size: 28px; color: var(--gold); font-weight: 600;
}
.method-list h3 { margin: 0; font-size: 24px; font-weight: 600; color: var(--navy); }
.method-list p { margin: 4px 0 0; color: var(--muted); font-size: 15px; }

/* === Split Head === */
.split-head {
  max-width: none;
  display: grid; grid-template-columns: 1.2fr 0.8fr;
  gap: 80px; align-items: end;
}
.split-head > p { padding-bottom: 8px; }

/* === Services === */
.service-rows { border-top: 1px solid var(--line); }
.service-rows article {
  display: grid; grid-template-columns: 70px 260px 1fr;
  padding: 34px 0; border-bottom: 1px solid var(--line);
  align-items: center;
}
.service-rows span, .training-list span {
  font-family: "Noto Serif SC", Georgia, serif;
  font-size: 20px; color: var(--gold); font-weight: 600;
}
.service-rows h3 { margin: 0; font-size: 22px; font-weight: 600; color: var(--navy); }
.service-rows p { margin: 0; color: var(--muted); font-size: 15px; }

/* === Deployment === */
.deployment {
  background: #eff0ec;
  max-width: none;
  padding-left: max(28px, calc((100vw - var(--max)) / 2));
  padding-right: max(28px, calc((100vw - var(--max)) / 2));
}
.deployment-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.deployment-grid article {
  background: var(--white); padding: 38px;
  min-height: 340px; display: flex; flex-direction: column;
  border: 1px solid var(--line);
}
.deployment-grid .featured {
  background: var(--navy); color: #fff; border-color: var(--navy);
}
.tag { font-size: 11px; color: var(--gold); font-weight: 600; letter-spacing: 0.08em; text-transform: uppercase; }
.featured .tag { color: var(--gold); }
.deployment-grid h3 {
  font-family: "Noto Serif SC", Georgia, serif;
  font-size: 28px; margin: 22px 0; font-weight: 600;
}
.deployment-grid p { color: var(--muted); line-height: 1.7; }
.deployment-grid .featured p { color: #bcc5d0; }
.deployment-grid b { margin-top: auto; font-size: 14px; }

/* === Products (精简，更像案例展示) === */
.product-showcase { display: grid; gap: 16px; }
.product {
  background: var(--white);
  display: grid; grid-template-columns: 0.7fr 1.3fr;
  min-height: 380px; overflow: hidden;
  border: 1px solid var(--line);
  transition: border-color 0.25s;
}
.product:hover { border-color: var(--gold); }
.product-copy {
  padding: 48px; display: flex; flex-direction: column;
  justify-content: center;
}
.product-copy > span { color: var(--gold); font-size: 11px; font-weight: 600; letter-spacing: 0.08em; text-transform: uppercase; }
.product-copy h3 {
  font-family: "Noto Serif SC", Georgia, serif;
  font-size: 42px; margin: 14px 0; font-weight: 600; color: var(--navy);
}
.product-copy p { color: var(--muted); line-height: 1.7; }
.product-copy b { margin-top: 24px; font-size: 14px; color: var(--gold); }
.product img { width: 100%; height: 100%; object-fit: cover; object-position: left top; }

.product-fde {
  grid-template-columns: 1fr 1fr;
  background: var(--navy); color: #fff; border-color: var(--navy);
}
.fde-visual {
  display: flex; flex-direction: column; justify-content: center;
  padding: 55px; background: #25374a; color: #fff;
}
.fde-visual span { font-size: 11px; letter-spacing: 0.08em; color: var(--gold); }
.fde-visual strong {
  max-width: 500px; margin: 22px 0;
  font-family: "Noto Serif SC", Georgia, serif;
  font-size: 44px; line-height: 1.12; font-weight: 600;
}
.fde-visual i { font-style: normal; color: #a8b4c2; font-size: 14px; }
.product-fde .product-copy p { color: #bcc5d0; }

.product-solo {
  grid-template-columns: 1.3fr 0.7fr;
  background: var(--navy); color: #fff; border-color: var(--navy);
}
.solo-visual {
  display: flex; flex-direction: column; justify-content: center;
  padding: 55px; background: #eef1f4; color: var(--navy);
}
.solo-visual span { font-size: 11px; letter-spacing: 0.08em; color: var(--gold); }
.solo-visual strong {
  font-family: "Noto Serif SC", Georgia, serif;
  font-size: 60px; line-height: 1.05; margin: 22px 0; font-weight: 600;
}
.solo-visual i { font-style: normal; color: var(--muted); font-size: 14px; }
.product-solo .product-copy p { color: #bcc5d0; }

/* === Training === */
.training-list {
  display: grid; grid-template-columns: repeat(2, 1fr);
  border-top: 1px solid var(--line);
}
.training-list article {
  padding: 34px 40px 44px 0; border-bottom: 1px solid var(--line);
}
.training-list article:nth-child(even) {
  border-left: 1px solid var(--line); padding-left: 40px;
}
.training-list h3 { font-size: 24px; margin: 18px 0 8px; font-weight: 600; color: var(--navy); }
.training-list p { color: var(--muted); margin: 0; font-size: 15px; }

/* === Pricing === */
.pricing {
  background: #f0ede6;
  max-width: none;
  padding-left: max(28px, calc((100vw - var(--max)) / 2));
  padding-right: max(28px, calc((100vw - var(--max)) / 2));
}
.price-category { margin-bottom: 48px; }
.price-category:last-child { margin-bottom: 0; }
.price-cat-title {
  font-family: "Noto Serif SC", Georgia, serif;
  font-size: 18px; font-weight: 600; color: var(--gold);
  margin: 0 0 12px; padding-bottom: 12px;
  border-bottom: 1px solid #d5cfc5;
}
.price-table { border-top: 1px solid #d5cfc5; }
.price-table div {
  display: grid; grid-template-columns: 200px 1fr auto;
  gap: 24px; align-items: center;
  padding: 24px 0; border-bottom: 1px solid #d5cfc5;
}
.price-table div > span {
  font-weight: 600; font-size: 16px; color: var(--navy);
}
.price-table div > p {
  margin: 0; color: var(--muted); font-size: 14px; line-height: 1.6;
}
.price-table strong {
  font-size: 18px; font-weight: 600; color: var(--navy); white-space: nowrap;
}
.price-note { max-width: 860px; color: #6b6560; margin-top: 36px; font-size: 14px; line-height: 1.7; }

/* === Founder === */
.founder {
  display: grid; grid-template-columns: 0.6fr 1.4fr; gap: 100px;
}
.founder-title h2 {
  font-family: "Noto Serif SC", Georgia, serif;
  font-size: 56px; margin: 0; font-weight: 600; color: var(--navy);
}
.founder-copy { font-size: 17px; }
.founder-lead {
  font-family: "Noto Serif SC", Georgia, serif;
  font-size: 26px; line-height: 1.5; margin-top: 0; color: var(--navy);
}
.founder blockquote {
  font-family: "Noto Serif SC", Georgia, serif;
  font-size: 21px; line-height: 1.6;
  border-left: 3px solid var(--gold);
  margin: 38px 0 0; padding-left: 24px;
  color: var(--muted);
}

/* === FAQ === */
.faq-list { border-top: 1px solid var(--line); }
.faq-list details { padding: 28px 0; border-bottom: 1px solid var(--line); }
.faq-list summary {
  cursor: pointer; font-size: 20px; font-weight: 600;
  list-style: none; outline: none;
}
.faq-list summary::-webkit-details-marker { display: none; }
.faq-list p { max-width: 760px; margin: 14px 0 0; color: var(--muted); font-size: 15px; line-height: 1.75; }

/* === Contact === */
.contact {
  background: var(--navy); color: #fff;
  max-width: none;
  padding-left: max(28px, calc((100vw - var(--max)) / 2));
  padding-right: max(28px, calc((100vw - var(--max)) / 2));
  display: grid; grid-template-columns: 1fr 1fr; gap: 90px;
}
.contact h2 {
  font-family: "Noto Serif SC", Georgia, serif;
  font-size: clamp(40px, 4.5vw, 58px);
  line-height: 1.1; margin: 0; font-weight: 600;
}
.contact > div > p:last-child { color: #a8b4c2; font-size: 17px; }
.contact form { display: grid; gap: 20px; }
.contact label { font-size: 12px; font-weight: 600; letter-spacing: 0.05em; }
.contact input, .contact textarea {
  display: block; width: 100%; border: 0;
  border-bottom: 1px solid #5a6d80; background: transparent;
  color: #fff; padding: 14px 0; outline: none; border-radius: 0;
  transition: border-color 0.2s;
}
.contact input:focus, .contact textarea:focus { border-color: var(--gold); }
.contact input::placeholder, .contact textarea::placeholder { color: #6b7d90; }
.contact .button { width: max-content; background: var(--gold); color: #fff; }
.contact .button:hover { background: #a88645; }
#form-status { margin: 0; color: #bcc5d0; }
.form-note { max-width: 500px; margin: 0; color: #8a9aad; font-size: 13px; }
.copy-wechat {
  padding: 0; border: 0; border-bottom: 1px solid currentColor;
  background: transparent; color: var(--gold); cursor: pointer;
  font-weight: 600;
}

/* === Footer === */
footer {
  max-width: var(--max); margin: auto;
  padding: 60px 28px;
  display: grid;
  grid-template-columns: 1fr 1.5fr 0.7fr;
  gap: 40px; align-items: start;
  border-bottom: 30px solid var(--navy);
}
footer p { margin: 0; color: var(--muted); font-size: 14px; }
footer div:nth-of-type(2) { display: flex; gap: 24px; }
footer small { grid-column: 1/-1; color: var(--muted); font-size: 13px; }

/* === Responsive === */
@media (max-width: 820px) {
  .site-header nav { display: none; }
  .hero { padding-top: 60px; min-height: auto; }
  .hero h1 { font-size: 46px; }
  .hero-signals, .problem-grid, .deployment-grid,
  .contact, .founder, .split-head, .product {
    grid-template-columns: 1fr;
  }
  .hero-signals { margin-top: 60px; }
  .hero-signals div + div { border-left: 0; border-top: 1px solid var(--line); padding-left: 0; }
  .problem-grid article + article { border-left: 0; border-top: 1px solid rgba(255,255,255,0.12); padding-left: 0; }
  .problem-grid article { min-height: 240px; }
  .section, .problem-band { padding-top: 80px; padding-bottom: 80px; }
  .split-head { gap: 16px; }
  .service-rows article { grid-template-columns: 45px 1fr; }
  .service-rows p { grid-column: 2; margin-top: 8px; }
  .product-solo .solo-visual { order: 2; }
  .fde-visual strong { font-size: 34px; }
  .solo-visual strong { font-size: 44px; }
  .training-list { grid-template-columns: 1fr; }
  .training-list article:nth-child(even) { border-left: 0; padding-left: 0; }
  .founder { gap: 35px; }
  .contact { gap: 50px; }
  .price-table div { display: block; }
  .price-table div > p { margin: 6px 0; }
  .price-table strong { display: block; margin-top: 8px; }
  .site-header { padding: 0 18px; }
  .section, .hero { padding-left: 18px; padding-right: 18px; }
  footer { grid-template-columns: 1fr; }
  footer small { grid-column: auto; }
}