:root {
  /* 主题：藏青金 —— 藏青深色区 + 品牌金点缀 */
  --ink: #1f2a3d;          /* 标题色 */
  --accent: #b18a4e;       /* 品牌金 */
  --accent-deep: #93713c;
  --bg: #f5f6f8;           /* 清透浅灰底 */
  --card: #ffffff;
  --text: #3c4352;
  --muted: #8a90a0;
  --line: #e3e6ec;
  --dark-1: #1f2940;       /* 深色区块（导航/Hero/页脚）藏青 */
  --dark-2: #2c3854;
  --radius: 14px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  font-family: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", "Helvetica Neue", Arial, sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.75;
  font-size: 16px;
}

img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
ul { list-style: none; }

.container { max-width: 1180px; margin: 0 auto; padding: 0 24px; }

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: color-mix(in srgb, var(--dark-1) 97%, transparent);
  backdrop-filter: blur(8px);
  box-shadow: 0 1px 0 rgba(255,255,255,0.06), 0 2px 16px rgba(0,0,0,0.18);
}
.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
}
.brand { display: flex; align-items: center; gap: 10px; color: #fff; }
.logo-img { height: 44px; width: auto; display: block; }
.brand .logo {
  font-size: 26px;
  font-weight: 800;
  letter-spacing: 2px;
  color: #fff;
}
.brand .logo em { color: var(--accent); font-style: normal; }
.brand .slogan { font-size: 12px; color: rgba(255,255,255,0.55); letter-spacing: 1px; }
.main-nav ul { display: flex; gap: 6px; }
.main-nav a {
  color: rgba(255,255,255,0.78);
  font-size: 15px;
  padding: 8px 14px;
  border-radius: 8px;
  transition: all .2s;
}
.main-nav a:hover, .main-nav a.active { color: #fff; background: rgba(255,255,255,0.1); }
.main-nav a.nav-cta {
  background: var(--accent);
  color: #fff;
  font-weight: 600;
}
.main-nav a.nav-cta:hover { background: var(--accent-deep); }

/* ---------- Hero ---------- */
.hero {
  background: linear-gradient(150deg, var(--dark-1) 0%, var(--dark-2) 100%);
  color: #fff;
  padding: 96px 0 110px;
  position: relative;
  overflow: hidden;
}
.hero::after {
  content: "";
  position: absolute;
  right: -140px; top: -140px;
  width: 480px; height: 480px;
  border-radius: 50%;
  background: radial-gradient(circle, color-mix(in srgb, var(--accent) 30%, transparent), transparent 70%);
}
.hero .kicker {
  display: inline-block;
  border: 1px solid rgba(160,131,85,0.55);
  color: var(--accent);
  font-size: 14px;
  padding: 6px 16px;
  border-radius: 999px;
  letter-spacing: 2px;
  margin-bottom: 22px;
}
.hero h1 {
  font-size: 46px;
  line-height: 1.3;
  font-weight: 800;
  max-width: 820px;
  margin-bottom: 18px;
}
.hero h1 .hl { color: var(--accent); }
.hero .sub {
  font-size: 18px;
  color: rgba(255,255,255,0.72);
  max-width: 720px;
  margin-bottom: 38px;
}
.hero-actions { display: flex; gap: 16px; flex-wrap: wrap; }
.btn {
  display: inline-block;
  padding: 14px 34px;
  border-radius: 10px;
  font-size: 16px;
  font-weight: 600;
  transition: all .2s;
}
.btn-primary { background: var(--accent); color: #fff; }
.btn-primary:hover { background: var(--accent-deep); transform: translateY(-2px); }
.btn-ghost { border: 1px solid rgba(255,255,255,0.35); color: #fff; }
.btn-ghost:hover { background: rgba(255,255,255,0.08); }

/* ---------- Stats ---------- */
.stats {
  background: #fff;
  border: 1px solid var(--line);
  box-shadow: 0 12px 40px rgba(27,26,23,0.06);
  margin-top: -56px;
  position: relative;
  z-index: 5;
  border-radius: var(--radius);
}
.stats .grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  padding: 34px 0;
}
.stat { text-align: center; border-right: 1px solid var(--line); }
.stat:last-child { border-right: none; }
.stat .num { font-size: 34px; font-weight: 800; color: var(--ink); }
.stat .num span { font-size: 18px; }
.stat .label { font-size: 14px; color: var(--muted); margin-top: 4px; }

/* ---------- Sections ---------- */
.section { padding: 84px 0; }
.section.alt { background: #fff; }
.section-head { text-align: center; max-width: 760px; margin: 0 auto 54px; }
.section-head .tag {
  color: var(--accent-deep);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 3px;
}
.section-head h2 { font-size: 34px; color: var(--ink); margin: 10px 0 14px; }
.section-head p { color: var(--muted); font-size: 16px; }

/* Pain points */
.pain-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.pain-item {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px 24px;
  display: flex;
  gap: 14px;
  align-items: flex-start;
}
.pain-item .icon {
  flex: none;
  width: 38px; height: 38px;
  border-radius: 10px;
  background: color-mix(in srgb, var(--accent) 13%, transparent);
  color: var(--accent-deep);
  display: flex; align-items: center; justify-content: center;
  font-weight: 800;
  font-size: 18px;
}
.pain-item p { font-size: 15px; color: var(--text); }

/* Product cards */
.product-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 24px; }
.product-card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 34px;
  position: relative;
  transition: all .25s;
}
.product-card:hover { transform: translateY(-4px); box-shadow: 0 18px 44px rgba(27,26,23,0.08); }
.product-card.featured {
  grid-column: 1 / -1;
  background: linear-gradient(130deg, var(--dark-1), var(--dark-2));
  color: #fff;
  border: none;
}
.product-card.featured .p-desc { color: rgba(255,255,255,0.72); }
.product-card .p-badge {
  position: absolute;
  top: 26px; right: 28px;
  background: var(--accent);
  color: #fff;
  font-size: 12px;
  font-weight: 700;
  padding: 5px 12px;
  border-radius: 999px;
}
.product-card .p-index { font-size: 13px; color: var(--accent-deep); font-weight: 800; letter-spacing: 2px; }
.product-card.featured .p-index { color: var(--accent); }
.product-card h3 { font-size: 24px; color: var(--ink); margin: 8px 0 12px; }
.product-card.featured h3 { color: #fff; }
.product-card .p-desc { color: var(--muted); font-size: 15px; margin-bottom: 18px; }
.product-card .p-meta { display: flex; gap: 22px; flex-wrap: wrap; margin-bottom: 20px; }
.product-card .p-meta div { font-size: 14px; color: var(--muted); }
.product-card .p-meta strong { display: block; font-size: 17px; color: var(--ink); }
.product-card.featured .p-meta strong { color: var(--accent); }
.product-card .p-link {
  display: inline-block;
  color: var(--accent-deep);
  font-weight: 600;
  font-size: 15px;
}
.product-card.featured .p-link { color: var(--accent); }

/* Timeline */
.timeline { position: relative; margin-left: 12px; padding-left: 30px; border-left: 2px solid var(--line); }
.timeline-item { position: relative; padding-bottom: 30px; }
.timeline-item:last-child { padding-bottom: 0; }
.timeline-item::before {
  content: "";
  position: absolute;
  left: -39px; top: 6px;
  width: 14px; height: 14px;
  border-radius: 50%;
  background: var(--accent);
  border: 3px solid var(--bg);
  box-shadow: 0 0 0 2px var(--accent);
}
.timeline-item .year { font-size: 20px; font-weight: 800; color: var(--ink); }
.timeline-item p { color: var(--muted); font-size: 15px; }

/* Cases */
.case-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 24px; }
.case-card {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 30px;
}
.case-card .c-tag { font-size: 13px; color: var(--accent-deep); font-weight: 700; letter-spacing: 1px; }
.case-card h3 { font-size: 20px; color: var(--ink); margin: 8px 0 10px; }
.case-card p { font-size: 14.5px; color: var(--muted); margin-bottom: 16px; }
.case-nums { display: flex; gap: 28px; border-top: 1px dashed var(--line); padding-top: 16px; }
.case-nums strong { display: block; font-size: 20px; color: var(--ink); }
.case-nums span { font-size: 13px; color: var(--muted); }

/* Industry tags */
.industry-tags { display: flex; flex-wrap: wrap; gap: 12px; justify-content: center; }
.industry-tags span {
  background: #fff;
  border: 1px solid var(--line);
  padding: 9px 20px;
  border-radius: 999px;
  font-size: 14.5px;
  color: var(--ink);
}

/* Gallery */
.gallery-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.gallery-grid figure { overflow: hidden; border-radius: var(--radius); border: 1px solid var(--line); }
.gallery-grid img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  transition: transform .4s ease;
}
.gallery-grid figure:hover img { transform: scale(1.04); }
.photo-row { display: grid; grid-template-columns: repeat(2, 1fr); gap: 18px; margin-top: 34px; }
.photo-row figure { overflow: hidden; border-radius: var(--radius); border: 1px solid var(--line); }
.photo-row img { width: 100%; aspect-ratio: 16 / 9; object-fit: cover; }

/* Teachers */
.teacher-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
.teacher-card {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 28px 22px;
  text-align: center;
}
.teacher-card .avatar {
  width: 84px; height: 84px;
  margin: 0 auto 14px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--dark-1), var(--dark-2));
  color: #fff;
  display: flex; align-items: center; justify-content: center;
  font-size: 26px;
  font-weight: 800;
  overflow: hidden;
}
.teacher-card .avatar img { width: 100%; height: 100%; object-fit: cover; object-position: top center; }
.teacher-card h3 { font-size: 18px; color: var(--ink); }
.teacher-card p { font-size: 13.5px; color: var(--muted); margin-top: 6px; }
.teacher-card.lead {
  grid-column: 1 / -1;
  display: flex;
  text-align: left;
  gap: 32px;
  align-items: center;
  background: linear-gradient(130deg, var(--dark-1), var(--dark-2));
  color: #fff;
  border: none;
}
.teacher-card.lead .avatar { margin: 0; width: 120px; height: 120px; font-size: 36px; flex: none; }
.teacher-card.lead h3 { color: #fff; font-size: 24px; }
.teacher-card.lead p { color: rgba(255,255,255,0.68); font-size: 15px; }
.teacher-card.lead .titles { display: flex; flex-direction: column; gap: 4px; }
.teacher-card.lead .titles em { color: var(--accent); font-style: normal; font-weight: 700; }

/* FAQ */
.faq-list { max-width: 860px; margin: 0 auto; }
.faq-item {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  margin-bottom: 14px;
  overflow: hidden;
}
.faq-item summary {
  cursor: pointer;
  padding: 20px 26px;
  font-weight: 600;
  color: var(--ink);
  font-size: 16.5px;
  list-style: none;
  position: relative;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after {
  content: "+";
  position: absolute;
  right: 24px; top: 50%;
  transform: translateY(-50%);
  font-size: 22px;
  color: var(--accent-deep);
}
.faq-item[open] summary::after { content: "−"; }
.faq-item .faq-a { padding: 0 26px 22px; color: var(--muted); font-size: 15px; }

/* CTA band */
.cta-band {
  background: var(--dark-1);
  color: #fff;
  text-align: center;
  padding: 70px 0;
  position: relative;
  overflow: hidden;
}
.cta-band::after {
  content: "";
  position: absolute;
  left: 50%; top: -160px;
  transform: translateX(-50%);
  width: 560px; height: 320px;
  background: radial-gradient(ellipse, color-mix(in srgb, var(--accent) 20%, transparent), transparent 70%);
}
.cta-band h2 { font-size: 30px; margin-bottom: 12px; position: relative; }
.cta-band p { color: rgba(255,255,255,0.7); margin-bottom: 28px; position: relative; }
.cta-band .btn { background: var(--accent); color: #fff; position: relative; }
.cta-band .btn:hover { background: var(--accent-deep); transform: translateY(-2px); }

/* Contact */
.contact-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.contact-card {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 30px;
  text-align: center;
}
.contact-card h3 { font-size: 17px; color: var(--ink); margin-bottom: 8px; }
.contact-card p { color: var(--muted); font-size: 15px; }
.contact-card strong { color: var(--accent-deep); font-size: 18px; }

/* Footer */
.site-footer {
  background: var(--dark-1);
  color: rgba(255,255,255,0.6);
  padding: 48px 0 30px;
  font-size: 14px;
}
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr; gap: 40px; margin-bottom: 34px; }
.site-footer h4 { color: #fff; font-size: 16px; margin-bottom: 14px; }
.footer-logo { height: 72px; width: auto; margin-bottom: 6px; }
.site-footer li { margin-bottom: 8px; }
.site-footer a:hover { color: var(--accent); }
.copyright { border-top: 1px solid rgba(255,255,255,0.1); padding-top: 22px; text-align: center; font-size: 13px; color: rgba(255,255,255,0.35); }

/* Course page specifics */
.day-card {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 34px;
  margin-bottom: 22px;
}
.day-card .day-label {
  display: inline-block;
  background: var(--ink);
  color: #fff;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 2px;
  padding: 5px 16px;
  border-radius: 999px;
  margin-bottom: 14px;
}
.day-card h3 { font-size: 22px; color: var(--ink); margin-bottom: 14px; }
.day-card ul li {
  position: relative;
  padding-left: 22px;
  color: var(--muted);
  font-size: 15px;
  margin-bottom: 8px;
}
.day-card ul li::before {
  content: "";
  position: absolute;
  left: 0; top: 11px;
  width: 8px; height: 8px;
  border-radius: 2px;
  background: var(--accent);
}
.gain-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.gain-card {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 32px 28px;
}
.gain-card .g-num {
  font-size: 40px;
  font-weight: 800;
  color: color-mix(in srgb, var(--accent) 24%, transparent);
  line-height: 1;
}
.gain-card h3 { font-size: 19px; color: var(--ink); margin: 10px 0 10px; }
.gain-card p { font-size: 14.5px; color: var(--muted); }

.price-box {
  max-width: 640px;
  margin: 0 auto;
  background: linear-gradient(130deg, var(--dark-1), var(--dark-2));
  color: #fff;
  border-radius: var(--radius);
  padding: 44px;
  text-align: center;
}
.price-box .price { font-size: 44px; font-weight: 800; color: var(--accent); }
.price-box .price small { font-size: 18px; font-weight: 500; }
.price-box .tip { color: rgba(255,255,255,0.65); margin-top: 8px; font-size: 15px; }

.check-list { display: grid; grid-template-columns: repeat(2, 1fr); gap: 14px; max-width: 860px; margin: 0 auto; }
.check-list li {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 14px 20px;
  font-size: 15px;
  color: var(--text);
  display: flex;
  gap: 10px;
}
.check-list li::before { content: "✓"; color: var(--accent-deep); font-weight: 800; }

/* Wide photo under hero */
.hero-photo { margin-top: -40px; position: relative; z-index: 6; }
.hero-photo img {
  width: 100%;
  aspect-ratio: 21 / 8;
  object-fit: cover;
  border-radius: var(--radius);
  border: 1px solid var(--line);
  box-shadow: 0 18px 50px rgba(27,26,23,0.14);
}

/* Responsive */
@media (max-width: 900px) {
  .hero h1 { font-size: 32px; }
  .stats .grid { grid-template-columns: repeat(2, 1fr); gap: 20px 0; }
  .stat:nth-child(2) { border-right: none; }
  .pain-grid, .gain-grid, .contact-grid { grid-template-columns: 1fr; }
  .product-grid, .case-grid, .check-list { grid-template-columns: 1fr; }
  .gallery-grid { grid-template-columns: 1fr; }
  .photo-row { grid-template-columns: 1fr; }
  .teacher-grid { grid-template-columns: repeat(2, 1fr); }
  .teacher-card.lead { flex-direction: column; text-align: center; }
  .footer-grid { grid-template-columns: 1fr; gap: 26px; }
  .main-nav ul { flex-wrap: wrap; gap: 2px; }
  .site-header .container { height: auto; padding: 10px 24px; flex-direction: column; gap: 8px; }
  .section { padding: 60px 0; }
}