/* ============ 基础 ============ */
:root {
  --navy: #0e2a47;
  --navy-deep: #081c33;
  --blue: #1d5fa8;
  --blue-soft: #eaf2fb;
  --gold: #c9a24b;
  --gold-deep: #a8843a;
  --ink: #1f2937;
  --gray: #64748b;
  --line: #e2e8f0;
  --bg: #ffffff;
  --bg-alt: #f6f8fb;
  --radius: 14px;
  --shadow: 0 10px 30px rgba(14, 42, 71, 0.08);
  --shadow-lg: 0 20px 50px rgba(14, 42, 71, 0.14);
  --font-serif: "Noto Serif SC", "Songti SC", serif;
  --font-sans: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 84px; }
body {
  font-family: var(--font-sans);
  color: var(--ink);
  background: var(--bg);
  line-height: 1.75;
  font-weight: 400;
}
img { max-width: 100%; display: block; }
a { text-decoration: none; color: inherit; }
ul { list-style: none; }
.container { width: min(1160px, 92%); margin: 0 auto; }

/* ============ 导航 ============ */
.navbar {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: box-shadow 0.3s, border-color 0.3s;
}
.navbar.scrolled { border-bottom-color: var(--line); box-shadow: 0 4px 20px rgba(14,42,71,.06); }
.nav-inner { display: flex; align-items: center; gap: 28px; height: 76px; }

.logo { display: flex; align-items: center; gap: 10px; }
.logo-mark {
  width: 42px; height: 42px; border-radius: 10px;
  background: linear-gradient(135deg, var(--navy), var(--blue));
  color: var(--gold); font-family: var(--font-serif); font-weight: 900;
  font-size: 22px; display: flex; align-items: center; justify-content: center;
}
.logo-text { font-family: var(--font-serif); font-weight: 700; font-size: 19px; color: var(--navy); line-height: 1.15; }
.logo-text small { display: block; font-family: var(--font-sans); font-size: 10px; letter-spacing: 2.5px; color: var(--gray); font-weight: 400; }

.nav-links { display: flex; gap: 4px; margin-left: auto; }
.nav-links a {
  padding: 8px 13px; font-size: 15px; color: #374151; border-radius: 8px;
  transition: color .2s, background .2s;
}
.nav-links a:hover { color: var(--blue); background: var(--blue-soft); }
.nav-links a.active { color: var(--navy); font-weight: 500; }

.nav-cta { white-space: nowrap; }
.nav-toggle { display: none; flex-direction: column; gap: 5px; background: none; border: 0; cursor: pointer; padding: 6px; }
.nav-toggle span { width: 24px; height: 2px; background: var(--navy); transition: .3s; }

/* ============ 按钮 ============ */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 10px 22px; border-radius: 999px; font-size: 15px; font-weight: 500;
  border: 1.5px solid transparent; cursor: pointer; transition: all .25s;
}
.btn-primary { background: linear-gradient(135deg, var(--navy), var(--blue)); color: #fff; }
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 8px 24px rgba(29,95,168,.35); }
.btn-ghost { border-color: rgba(255,255,255,.6); color: #fff; }
.btn-ghost:hover { background: rgba(255,255,255,.12); }
.btn-lg { padding: 14px 32px; font-size: 16px; }
.btn-block { width: 100%; }

/* ============ Hero ============ */
.hero {
  position: relative; padding: 170px 0 90px; color: #fff; overflow: hidden;
  background: linear-gradient(140deg, var(--navy-deep) 0%, var(--navy) 55%, #16406d 100%);
}
.hero-bg {
  position: absolute; inset: 0; opacity: .5;
  background:
    radial-gradient(ellipse 60% 50% at 80% 20%, rgba(29,95,168,.55), transparent 60%),
    radial-gradient(ellipse 50% 60% at 10% 90%, rgba(201,162,75,.18), transparent 60%);
}
.hero-bg::after {
  content: ""; position: absolute; inset: 0;
  background-image: linear-gradient(rgba(255,255,255,.045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,.045) 1px, transparent 1px);
  background-size: 56px 56px;
  mask-image: radial-gradient(ellipse 80% 70% at 60% 40%, #000, transparent 75%);
}
.hero-content { position: relative; z-index: 1; text-align: center; }
.hero-kicker {
  display: inline-block; font-size: 14px; letter-spacing: 3px; color: var(--gold);
  border: 1px solid rgba(201,162,75,.45); padding: 6px 18px; border-radius: 999px; margin-bottom: 26px;
}
.hero-title {
  font-family: var(--font-serif); font-weight: 900; font-size: clamp(38px, 6vw, 64px);
  line-height: 1.25; letter-spacing: 1px;
}
.hero-title .accent { color: var(--gold); }
.hero-sub { margin: 24px auto 36px; max-width: 640px; color: rgba(255,255,255,.82); font-size: 17px; font-weight: 300; }
.hero-actions { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }

.hero-stats {
  margin-top: 72px; display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px;
  border-top: 1px solid rgba(255,255,255,.15); padding-top: 36px; max-width: 860px; margin-left: auto; margin-right: auto;
}
.stat strong { display: block; font-family: var(--font-serif); font-size: 40px; color: #fff; }
.stat strong::after { content: "+"; color: var(--gold); font-size: 24px; vertical-align: super; margin-left: 2px; }
.stat span { font-size: 14px; color: rgba(255,255,255,.65); }

/* ============ 信任条 ============ */
.trustbar { padding: 30px 0; border-bottom: 1px solid var(--line); background: var(--bg); }
.trust-label { text-align: center; font-size: 12px; letter-spacing: 2px; color: var(--gray); margin-bottom: 14px; }
.trust-logos { display: flex; flex-wrap: wrap; justify-content: center; gap: 14px 48px; }
.trust-logos span {
  font-family: var(--font-serif); font-size: 18px; font-weight: 700; color: #94a3b8;
  transition: color .3s; cursor: default;
}
.trust-logos span:hover { color: var(--navy); }

/* ============ 区块通用 ============ */
.section { padding: 96px 0; }
.section-alt { background: var(--bg-alt); }
.section-head { text-align: center; max-width: 640px; margin: 0 auto 56px; }
.section-kicker { font-size: 13px; letter-spacing: 4px; color: var(--gold-deep); font-weight: 500; margin-bottom: 10px; }
.section-title { font-family: var(--font-serif); font-size: clamp(28px, 4vw, 40px); color: var(--navy); font-weight: 900; }
.section-desc { color: var(--gray); margin-top: 12px; }
.grid { display: grid; gap: 24px; }

.card {
  background: #fff; border-radius: var(--radius); border: 1px solid var(--line);
  box-shadow: var(--shadow); transition: transform .3s, box-shadow .3s;
}
.card:hover { transform: translateY(-6px); box-shadow: var(--shadow-lg); }

/* ============ 服务 ============ */
.services-grid { grid-template-columns: repeat(4, 1fr); }
.service-card { padding: 34px 28px; border-top: 3px solid transparent; }
.service-card:hover { border-top-color: var(--gold); }
.service-icon {
  width: 56px; height: 56px; border-radius: 12px; font-size: 26px;
  background: var(--blue-soft); color: var(--blue);
  display: flex; align-items: center; justify-content: center; margin-bottom: 20px;
}
.service-card h3 { font-family: var(--font-serif); color: var(--navy); font-size: 21px; margin-bottom: 12px; }
.service-card > p { font-size: 14.5px; color: var(--gray); margin-bottom: 16px; }
.service-card ul { border-top: 1px dashed var(--line); padding-top: 14px; }
.service-card li { font-size: 14px; color: #374151; padding: 5px 0 5px 20px; position: relative; }
.service-card li::before { content: "▸"; position: absolute; left: 2px; color: var(--gold-deep); }

/* ============ 方法论 ============ */
.method-flow { display: grid; grid-template-columns: repeat(5, 1fr); gap: 18px; }
.method-step {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius);
  padding: 28px 22px; position: relative; transition: transform .3s, border-color .3s;
}
.method-step:hover { transform: translateY(-6px); border-color: var(--gold); }
.method-step:not(:last-child)::after {
  content: "→"; position: absolute; right: -17px; top: 50%; transform: translateY(-50%);
  color: var(--gold-deep); font-weight: 700; z-index: 2; background: var(--bg-alt); padding: 2px;
}
.step-num { font-family: var(--font-serif); font-size: 34px; font-weight: 900; color: rgba(29,95,168,.15); }
.method-step h4 { color: var(--navy); margin: 6px 0 8px; font-size: 17px; }
.method-step p { font-size: 13.5px; color: var(--gray); }

/* ============ 案例 ============ */
.cases-grid { grid-template-columns: repeat(3, 1fr); }
.case-card { padding: 32px 28px; display: flex; flex-direction: column; }
.case-tag {
  align-self: flex-start; font-size: 12.5px; color: var(--blue); background: var(--blue-soft);
  padding: 4px 12px; border-radius: 999px; margin-bottom: 16px; font-weight: 500;
}
.case-card h3 { font-family: var(--font-serif); font-size: 19px; color: var(--navy); margin-bottom: 12px; line-height: 1.5; }
.case-card p { font-size: 14.5px; color: var(--gray); flex: 1; }
.case-metrics { display: flex; gap: 26px; border-top: 1px solid var(--line); margin-top: 20px; padding-top: 18px; }
.case-metrics strong { display: block; font-family: var(--font-serif); font-size: 24px; color: var(--gold-deep); }
.case-metrics span { font-size: 12.5px; color: var(--gray); }

/* ============ 团队 ============ */
.team-grid { grid-template-columns: repeat(4, 1fr); }
.team-card { padding: 34px 26px; text-align: center; }
.avatar {
  width: 88px; height: 88px; margin: 0 auto 18px; border-radius: 50%;
  background: linear-gradient(135deg, var(--navy), var(--blue));
  color: #fff; font-family: var(--font-serif); font-size: 36px; font-weight: 700;
  display: flex; align-items: center; justify-content: center;
  border: 3px solid var(--gold);
}
.team-card h3 { font-family: var(--font-serif); font-size: 19px; color: var(--navy); }
.team-card h3 span { display: block; font-family: var(--font-sans); font-size: 13px; color: var(--gold-deep); font-weight: 400; margin-top: 4px; }
.team-card p { font-size: 13.5px; color: var(--gray); margin-top: 12px; }

/* ============ 痛点诊断 ============ */
.pain-grid { grid-template-columns: repeat(3, 1fr); }
.pain-card { padding: 30px 26px; border-left: 3px solid transparent; }
.pain-card:hover { border-left-color: var(--gold); }
.pain-icon {
  width: 48px; height: 48px; border-radius: 10px; font-size: 22px;
  background: #fdf3e3; color: var(--gold-deep);
  display: flex; align-items: center; justify-content: center; margin-bottom: 16px;
}
.pain-card h3 { font-family: var(--font-serif); color: var(--navy); font-size: 19px; margin-bottom: 10px; }
.pain-card p { font-size: 14px; color: var(--gray); }
.pain-tail {
  text-align: center; margin-top: 44px; font-size: 16.5px; color: var(--ink);
}
.pain-tail a { color: var(--blue); font-weight: 500; }
.pain-tail a:hover { text-decoration: underline; }

/* ============ 服务（五列变体） ============ */
.services-five { grid-template-columns: repeat(5, 1fr); }
.services-five .service-card { padding: 30px 22px; }
.services-five .service-card h3 { font-size: 19px; }

/* ============ 方法（四步变体）与承诺卡 ============ */
.method-four { grid-template-columns: repeat(4, 1fr); }
.method-note { margin-top: 40px; padding: 28px 34px; background: #fff; }
.method-note strong { font-family: var(--font-serif); color: var(--navy); font-size: 17px; display: block; margin-bottom: 8px; }
.method-note p { font-size: 14.5px; color: var(--gray); }

/* ============ 洞察 ============ */
.insights-grid { grid-template-columns: repeat(3, 1fr); }
.article-card { padding: 30px 28px; display: flex; flex-direction: column; }
.article-cat { align-self: flex-start; font-size: 12.5px; color: var(--gold-deep); letter-spacing: 1px; margin-bottom: 12px; }
.article-card h3 { font-family: var(--font-serif); font-size: 19px; color: var(--navy); line-height: 1.55; margin-bottom: 10px; }
.article-card p { font-size: 14px; color: var(--gray); flex: 1; }
.article-meta { margin-top: 16px; font-size: 14px; color: var(--blue); font-weight: 500; }

/* ============ 联系 ============ */
.contact { background: linear-gradient(160deg, var(--navy-deep), var(--navy)); color: #fff; }
.contact-wrap { display: grid; grid-template-columns: 1.05fr 1fr; gap: 64px; align-items: start; }
.contact .section-kicker { color: var(--gold); }
.contact .section-title { color: #fff; }
.contact-desc { color: rgba(255,255,255,.78); margin-top: 16px; font-weight: 300; }
.contact-details { margin-top: 34px; display: grid; gap: 14px; }
.contact-details li { display: flex; gap: 18px; align-items: baseline; color: rgba(255,255,255,.88); }
.ci-label {
  min-width: 52px; font-size: 12.5px; letter-spacing: 2px; color: var(--gold);
  border: 1px solid rgba(201,162,75,.4); border-radius: 999px; text-align: center; padding: 2px 10px;
}
.contact-form { padding: 36px 32px; color: var(--ink); }
.contact-form h3 { font-family: var(--font-serif); color: var(--navy); font-size: 21px; margin-bottom: 22px; }
.contact-form label { display: block; font-size: 13.5px; color: #374151; font-weight: 500; margin-bottom: 14px; }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
.contact-form input, .contact-form select, .contact-form textarea {
  width: 100%; margin-top: 6px; padding: 11px 14px; border: 1px solid var(--line);
  border-radius: 10px; font-size: 14.5px; font-family: inherit; background: #fbfcfe;
  transition: border-color .2s, box-shadow .2s; color: var(--ink);
}
.contact-form input:focus, .contact-form select:focus, .contact-form textarea:focus {
  outline: none; border-color: var(--blue); box-shadow: 0 0 0 3px rgba(29,95,168,.12); background: #fff;
}
.contact-form .btn { margin-top: 8px; }
.form-note { margin-top: 14px; text-align: center; color: #059669; font-size: 14px; font-weight: 500; }

/* ============ 页脚 ============ */
.footer { background: var(--navy-deep); color: rgba(255,255,255,.75); padding: 64px 0 0; }
.footer-inner { display: grid; grid-template-columns: 1.6fr 1fr 1fr 1.2fr; gap: 40px; padding-bottom: 48px; }
.footer .logo-text { color: #fff; }
.footer-brand p { margin-top: 18px; font-size: 14px; font-weight: 300; color: rgba(255,255,255,.6); }
.footer-col h4 { color: #fff; font-size: 15px; margin-bottom: 16px; font-weight: 500; }
.footer-col a { display: block; font-size: 14px; padding: 5px 0; color: rgba(255,255,255,.62); transition: color .2s; }
.footer-col a:hover { color: var(--gold); }
.footer-bottom { border-top: 1px solid rgba(255,255,255,.1); padding: 20px 0; }
.footer-bottom p { font-size: 12.5px; color: rgba(255,255,255,.42); text-align: center; }

/* ============ 回到顶部 ============ */
.back-top {
  position: fixed; right: 26px; bottom: 26px; width: 46px; height: 46px; border-radius: 50%;
  background: var(--navy); color: #fff; border: 0; font-size: 18px; cursor: pointer;
  box-shadow: var(--shadow-lg); opacity: 0; visibility: hidden; transform: translateY(10px);
  transition: all .3s; z-index: 90;
}
.back-top.show { opacity: 1; visibility: visible; transform: translateY(0); }
.back-top:hover { background: var(--blue); }

/* ============ 入场动画 ============ */
.reveal { opacity: 0; transform: translateY(26px); transition: opacity .7s ease, transform .7s ease; }
.reveal.visible { opacity: 1; transform: translateY(0); }

/* ============ 响应式 ============ */
@media (max-width: 1020px) {
  .services-grid, .services-five, .team-grid, .team-four { grid-template-columns: repeat(2, 1fr); }
  .cases-grid, .insights-grid { grid-template-columns: repeat(2, 1fr); }
  .pain-grid { grid-template-columns: repeat(2, 1fr); }
  .method-flow, .method-four { grid-template-columns: repeat(3, 1fr); }
  .method-step:nth-child(3n)::after { display: none; }
  .contact-wrap { grid-template-columns: 1fr; gap: 44px; }
  .footer-inner { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 720px) {
  .nav-links, .nav-cta {
    position: fixed; top: 76px; left: 0; right: 0; background: #fff;
    flex-direction: column; padding: 18px 6%;
    border-bottom: 1px solid var(--line); box-shadow: var(--shadow);
    transform: translateY(-130%); transition: transform .35s; z-index: 99;
  }
  .nav-links.open, .nav-cta.open { transform: translateY(0); }
  .nav-cta { top: 76px; }
  .nav-links { top: 150px; }
  .nav-toggle { display: flex; margin-left: auto; }
  .hero { padding: 130px 0 70px; }
  .hero-stats { grid-template-columns: repeat(2, 1fr); gap: 26px 14px; }
  .services-grid, .services-five, .cases-grid, .insights-grid, .team-grid, .team-four { grid-template-columns: 1fr; }
  .pain-grid { grid-template-columns: 1fr; }
  .method-flow, .method-four { grid-template-columns: 1fr; }
  .method-step::after { display: none !important; }
  .form-row { grid-template-columns: 1fr; }
  .footer-inner { grid-template-columns: 1fr; gap: 30px; }
  .section { padding: 70px 0; }
}