/* ========================================
   飞训航中官网 - 全局样式
   GEO优化：语义清晰结构，无冗余嵌套
======================================== */

:root {
  --primary: #0052CC;
  --primary-dark: #003A99;
  --accent: #0073E6;
  --text: #1A1A2E;
  --text-light: #555;
  --bg-light: #F5F8FF;
  --border: #E0E8F5;
  --white: #ffffff;
  --section-gap: 80px;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  color: var(--text);
  line-height: 1.7;
  font-size: 16px;
}

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

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

/* ---- 按钮 ---- */
.btn {
  display: inline-block;
  padding: 13px 32px;
  border-radius: 6px;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.25s;
  border: 2px solid transparent;
}
.btn-primary {
  background: var(--primary);
  color: #fff;
}
.btn-primary:hover { background: var(--primary-dark); }
.btn-accent {
  background: var(--accent);
  color: #fff;
}
.btn-accent:hover { opacity: 0.9; }
.btn-outline {
  border-color: var(--primary);
  color: var(--primary);
  background: transparent;
}
.btn-outline:hover { background: var(--primary); color: #fff; }

/* ---- 导航 ---- */
.navbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 999;
  background: rgba(255,255,255,0.97);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
  height: 68px;
}
.navbar .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}
.logo {
  font-size: 13px;
  font-weight: 700;
  color: var(--primary);
  letter-spacing: 0;
  white-space: nowrap;
}
.logo span { color: var(--primary); }

.nav-links {
  display: flex;
  list-style: none;
  gap: 36px;
  align-items: center;
}
.nav-links a {
  font-size: 15px;
  color: var(--text);
  position: relative;
  transition: color 0.2s;
}
.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -4px; left: 0;
  width: 0; height: 2px;
  background: var(--primary);
  transition: width 0.25s;
}
.nav-links a:hover,
.nav-links a.active { color: var(--primary); }
.nav-links a:hover::after,
.nav-links a.active::after { width: 100%; }
.nav-links .nav-cta .btn { padding: 9px 22px; font-size: 14px; }
.btn-primary { color: #fff !important; }
.btn-accent { color: #fff !important; }

/* 移动端汉堡 */
.hamburger { display: none; flex-direction: column; gap: 5px; cursor: pointer; }
.hamburger span { display: block; width: 24px; height: 2px; background: var(--text); border-radius: 2px; transition: all 0.3s; }

/* ---- Section 通用 ---- */
.section { padding: var(--section-gap) 0; }
.section-alt { background: var(--bg-light); }
.section-dark { background: var(--primary); color: #fff; }

.section-header { text-align: center; margin-bottom: 52px; }
.section-header h2 {
  font-size: 32px;
  font-weight: 700;
  margin-bottom: 14px;
  line-height: 1.3;
}
.section-header p {
  font-size: 17px;
  color: var(--text-light);
  max-width: 560px;
  margin: 0 auto;
}
.section-dark .section-header p { color: rgba(255,255,255,0.8); }

.tag-line {
  display: inline-block;
  background: rgba(0,82,204,0.08);
  color: var(--primary);
  font-size: 13px;
  font-weight: 600;
  padding: 4px 14px;
  border-radius: 20px;
  margin-bottom: 12px;
  letter-spacing: 0.05em;
}

/* ---- Hero ---- */
.hero {
  min-height: 100vh;
  background: linear-gradient(135deg, #001A4D 0%, #003A99 50%, #0052CC 100%);
  display: flex;
  align-items: center;
  position: relative;
  overflow: hidden;
  padding-top: 68px;
}
.hero::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0; bottom: 0;
  background: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.03'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
}
.hero-content { position: relative; z-index: 1; max-width: 700px; }
.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: rgba(255,255,255,0.12);
  border: 1px solid rgba(255,255,255,0.2);
  color: #fff;
  font-size: 13px;
  padding: 6px 16px;
  border-radius: 24px;
  margin-bottom: 28px;
}
.hero h1 {
  font-size: clamp(32px, 5vw, 54px);
  font-weight: 800;
  color: #fff;
  line-height: 1.2;
  margin-bottom: 20px;
}
.hero h1 em {
  font-style: normal;
  color: #FFB347;
}
.hero p {
  font-size: 18px;
  color: rgba(255,255,255,0.85);
  margin-bottom: 40px;
  max-width: 560px;
}
.hero-actions { display: flex; gap: 16px; flex-wrap: wrap; }
.hero-stats {
  display: flex;
  gap: 40px;
  margin-top: 56px;
  padding-top: 40px;
  border-top: 1px solid rgba(255,255,255,0.15);
}
.hero-stat strong {
  display: block;
  font-size: 36px;
  font-weight: 800;
  color: #fff;
}
.hero-stat span {
  font-size: 14px;
  color: rgba(255,255,255,0.7);
}

/* ---- 优势卡片 ---- */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
}
.feature-card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 32px 28px;
  transition: box-shadow 0.25s, transform 0.25s;
}
.feature-card:hover {
  box-shadow: 0 8px 32px rgba(0,82,204,0.12);
  transform: translateY(-4px);
}
.feature-icon {
  width: 52px; height: 52px;
  background: var(--bg-light);
  border-radius: 12px;
  display: flex; align-items: center; justify-content: center;
  font-size: 26px;
  margin-bottom: 20px;
}
.feature-card h3 { font-size: 18px; margin-bottom: 10px; }
.feature-card p { font-size: 14px; color: var(--text-light); }

/* ---- 业务双栏 ---- */
.biz-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}
.biz-card {
  border-radius: 16px;
  overflow: hidden;
  position: relative;
  min-height: 280px;
  display: flex;
  align-items: flex-end;
  cursor: pointer;
}
.biz-card-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
}
.biz-card-bg.training {
  background: linear-gradient(135deg, #003A99, #0052CC);
}
.biz-card-bg.service {
  background: linear-gradient(135deg, #1A1A2E, #2D3561);
}
.biz-card-pattern {
  position: absolute;
  inset: 0;
  opacity: 0.07;
  font-size: 120px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
}
.biz-card-body {
  position: relative;
  z-index: 1;
  padding: 32px;
  color: #fff;
  width: 100%;
  background: linear-gradient(to top, rgba(0,0,0,0.5) 0%, transparent 100%);
}
.biz-card-body h3 { font-size: 24px; font-weight: 700; margin-bottom: 10px; }
.biz-card-body p { font-size: 14px; opacity: 0.85; margin-bottom: 20px; }

/* ---- 应用场景 ---- */
.scenes-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}
.scene-card {
  border-radius: 12px;
  overflow: hidden;
  background: #fff;
  border: 1px solid var(--border);
  transition: box-shadow 0.25s;
}
.scene-card:hover { box-shadow: 0 6px 24px rgba(0,82,204,0.1); }
.scene-icon-box {
  height: 120px;
  display: flex; align-items: center; justify-content: center;
  font-size: 52px;
  background: var(--bg-light);
}
.scene-card-body { padding: 20px; }
.scene-card-body h3 { font-size: 16px; font-weight: 600; margin-bottom: 6px; }
.scene-card-body p { font-size: 13px; color: var(--text-light); }

/* ---- CTA 条 ---- */
.cta-bar {
  background: linear-gradient(90deg, var(--primary) 0%, var(--primary-dark) 100%);
  color: #fff;
  padding: 60px 0;
  text-align: center;
}
.cta-bar h2 { font-size: 28px; margin-bottom: 12px; }
.cta-bar p { font-size: 16px; opacity: 0.85; margin-bottom: 32px; }
.cta-contacts {
  display: flex;
  justify-content: center;
  gap: 40px;
  flex-wrap: wrap;
  margin-top: 32px;
  font-size: 15px;
}
.cta-contacts a { color: #fff; opacity: 0.9; }
.cta-contacts a:hover { opacity: 1; }

/* ---- 页脚 ---- */
footer {
  background: #0D1120;
  color: rgba(255,255,255,0.7);
  padding: 56px 0 28px;
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 48px;
}
.footer-brand .logo { color: #fff; margin-bottom: 14px; }
.footer-brand p { font-size: 14px; line-height: 1.7; }
.footer-col h4 {
  color: #fff;
  font-size: 14px;
  font-weight: 600;
  margin-bottom: 16px;
  letter-spacing: 0.05em;
}
.footer-col ul { list-style: none; }
.footer-col li { margin-bottom: 10px; }
.footer-col a { font-size: 14px; color: rgba(255,255,255,0.6); transition: color 0.2s; }
.footer-col a:hover { color: #fff; }
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.08);
  padding-top: 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 13px;
  flex-wrap: wrap;
  gap: 10px;
}

/* ---- 页面内页头 ---- */
.page-hero {
  background: linear-gradient(135deg, #001A4D, #0052CC);
  padding: 120px 0 70px;
  color: #fff;
  text-align: center;
}
.page-hero h1 { font-size: 40px; font-weight: 800; margin-bottom: 14px; }
.page-hero p { font-size: 18px; opacity: 0.85; }

/* ---- 课程卡片 ---- */
.courses-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.course-card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 14px;
  overflow: hidden;
  transition: box-shadow 0.25s, transform 0.25s;
}
.course-card:hover { box-shadow: 0 8px 32px rgba(0,82,204,0.13); transform: translateY(-5px); }
.course-card-head {
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  padding: 28px;
  color: #fff;
  text-align: center;
}
.course-card-head .icon { font-size: 44px; margin-bottom: 14px; }
.course-card-head h3 { font-size: 18px; font-weight: 700; }
.course-card-body { padding: 24px; }
.course-card-body p { font-size: 14px; color: var(--text-light); margin-bottom: 16px; }
.course-tags { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 18px; }
.tag {
  background: var(--bg-light);
  color: var(--primary);
  font-size: 12px;
  padding: 4px 12px;
  border-radius: 20px;
  font-weight: 500;
}
.course-meta { border-top: 1px solid var(--border); padding-top: 16px; }
.course-meta li { font-size: 13px; color: var(--text-light); margin-bottom: 6px; padding-left: 16px; position: relative; }
.course-meta li::before { content: '✓'; position: absolute; left: 0; color: var(--primary); }

/* ---- 流程步骤 ---- */
.steps { display: flex; gap: 0; position: relative; }
.steps::before {
  content: '';
  position: absolute;
  top: 32px; left: 32px; right: 32px;
  height: 2px;
  background: var(--border);
}
.step {
  flex: 1;
  text-align: center;
  position: relative;
}
.step-num {
  width: 64px; height: 64px;
  border-radius: 50%;
  background: var(--primary);
  color: #fff;
  font-size: 20px;
  font-weight: 700;
  display: flex; align-items: center; justify-content: center;
  margin: 0 auto 16px;
  position: relative; z-index: 1;
}
.step h4 { font-size: 15px; font-weight: 600; margin-bottom: 6px; }
.step p { font-size: 13px; color: var(--text-light); }

/* ---- FAQ ---- */
.faq-list { max-width: 800px; margin: 0 auto; }
.faq-item {
  border: 1px solid var(--border);
  border-radius: 10px;
  margin-bottom: 12px;
  overflow: hidden;
}
.faq-q {
  padding: 20px 24px;
  font-weight: 600;
  font-size: 15px;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: #fff;
  transition: background 0.2s;
}
.faq-q:hover { background: var(--bg-light); }
.faq-q .icon { transition: transform 0.3s; flex-shrink: 0; }
.faq-item.open .faq-q .icon { transform: rotate(180deg); }
.faq-a {
  padding: 0 24px;
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s ease, padding 0.3s;
  font-size: 14px;
  color: var(--text-light);
  line-height: 1.8;
  background: #fff;
}
.faq-item.open .faq-a {
  max-height: 300px;
  padding: 0 24px 20px;
}

/* ---- 服务页 ---- */
.services-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 24px; }
.service-card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 32px;
  display: flex;
  gap: 20px;
  transition: box-shadow 0.25s;
}
.service-card:hover { box-shadow: 0 6px 24px rgba(0,82,204,0.1); }
.service-icon { font-size: 44px; flex-shrink: 0; }
.service-card h3 { font-size: 18px; font-weight: 700; margin-bottom: 10px; }
.service-card p { font-size: 14px; color: var(--text-light); line-height: 1.7; }
.service-card ul { margin-top: 12px; list-style: none; }
.service-card ul li { font-size: 13px; color: var(--text-light); padding-left: 16px; position: relative; margin-bottom: 4px; }
.service-card ul li::before { content: '·'; position: absolute; left: 4px; color: var(--primary); font-weight: bold; }

/* ---- 关于页 ---- */
.about-intro { display: grid; grid-template-columns: 1fr 1fr; gap: 60px; align-items: center; }
.about-intro-text h2 { font-size: 32px; font-weight: 700; margin-bottom: 20px; }
.about-intro-text p { font-size: 15px; color: var(--text-light); margin-bottom: 16px; line-height: 1.8; }
.cert-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.cert-card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 28px 20px;
  text-align: center;
}
.cert-card .icon { font-size: 40px; margin-bottom: 14px; }
.cert-card h4 { font-size: 15px; font-weight: 600; }
.cert-card p { font-size: 13px; color: var(--text-light); margin-top: 6px; }

/* ---- 联系页 ---- */
.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; }
.contact-info h2 { font-size: 28px; font-weight: 700; margin-bottom: 24px; }
.contact-item {
  display: flex; gap: 14px;
  margin-bottom: 24px;
  align-items: flex-start;
}
.contact-item-icon {
  width: 44px; height: 44px;
  background: var(--bg-light);
  border-radius: 10px;
  display: flex; align-items: center; justify-content: center;
  font-size: 20px;
  flex-shrink: 0;
}
.contact-item h4 { font-size: 14px; color: var(--text-light); margin-bottom: 4px; }
.contact-item p { font-size: 15px; font-weight: 500; }
.contact-form { background: #fff; border: 1px solid var(--border); border-radius: 14px; padding: 36px; }
.contact-form h3 { font-size: 20px; font-weight: 700; margin-bottom: 24px; }
.form-group { margin-bottom: 18px; }
.form-group label { display: block; font-size: 14px; font-weight: 500; margin-bottom: 6px; }
.form-group input,
.form-group select,
.form-group textarea {
  width: 100%;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 12px 16px;
  font-size: 14px;
  font-family: inherit;
  transition: border-color 0.2s;
  outline: none;
  background: var(--bg-light);
  color: var(--text);
}
.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus { border-color: var(--primary); background: #fff; }
.form-group textarea { height: 110px; resize: vertical; }
.form-success {
  display: none;
  text-align: center;
  padding: 32px;
  color: #00A550;
  font-size: 15px;
}

/* ---- 响应式 ---- */
@media (max-width: 900px) {
  .features-grid { grid-template-columns: 1fr 1fr; }
  .biz-grid { grid-template-columns: 1fr; }
  .scenes-grid { grid-template-columns: 1fr 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .courses-grid { grid-template-columns: 1fr 1fr; }
  .services-grid { grid-template-columns: 1fr; }
  .about-intro { grid-template-columns: 1fr; gap: 36px; }
  .contact-grid { grid-template-columns: 1fr; }
  .steps { flex-direction: column; }
  .steps::before { display: none; }
}

@media (max-width: 640px) {
  :root { --section-gap: 56px; }
  .nav-links { display: none; }
  .hamburger { display: flex; }
  .nav-links.open {
    display: flex;
    flex-direction: column;
    position: fixed;
    top: 68px; left: 0; right: 0;
    background: #fff;
    padding: 20px 24px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
    gap: 20px;
    border-bottom: 1px solid var(--border);
  }
  .features-grid { grid-template-columns: 1fr; }
  .scenes-grid { grid-template-columns: 1fr; }
  .courses-grid { grid-template-columns: 1fr; }
  .cert-grid { grid-template-columns: 1fr 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .hero-stats { flex-wrap: wrap; gap: 24px; }
  .section-header h2 { font-size: 26px; }
  .page-hero h1 { font-size: 28px; }
}