/* ===== Reset & Base ===== */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }

:root {
  --primary: #0a1f3d;
  --primary-light: #132d50;
  --accent: #00bcd4;
  --accent-hover: #00a0b3;
  --gold: #f0c040;
  --text: #e0e8f0;
  --text-dark: #1a1a2e;
  --bg: #f5f7fa;
  --white: #ffffff;
  --gray: #6b7a8a;
  --light-gray: #eef1f5;
  --shadow: 0 4px 20px rgba(0,0,0,0.08);
  --radius: 12px;
  --transition: all 0.3s ease;
}

html { scroll-behavior: smooth; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  color: var(--text-dark);
  background: var(--bg);
  line-height: 1.7;
}

/* ===== Header / Nav ===== */
header {
  position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
  background: rgba(10, 31, 61, 0.95);
  backdrop-filter: blur(10px);
  box-shadow: 0 2px 20px rgba(0,0,0,0.2);
}
nav {
  max-width: 1200px; margin: 0 auto; padding: 0 24px;
  display: flex; align-items: center; justify-content: space-between;
  height: 72px;
}
.logo {
  font-size: 1.6rem; font-weight: 700; color: var(--white);
  text-decoration: none; letter-spacing: 2px;
}
.logo span { color: var(--accent); }
.logo small { font-size: 0.55rem; font-weight: 400; color: var(--gray); margin-left: 8px; }

.nav-links { display: flex; gap: 32px; list-style: none; }
.nav-links a {
  color: var(--text); text-decoration: none; font-size: 0.95rem;
  font-weight: 500; transition: var(--transition); position: relative;
}
.nav-links a::after {
  content: ''; position: absolute; left: 0; bottom: -4px;
  width: 0; height: 2px; background: var(--accent); transition: var(--transition);
}
.nav-links a:hover, .nav-links a.active { color: var(--accent); }
.nav-links a:hover::after, .nav-links a.active::after { width: 100%; }

.hamburger { display: none; flex-direction: column; gap: 5px; cursor: pointer; background: none; border: none; }
.hamburger span { width: 28px; height: 2px; background: var(--white); border-radius: 2px; transition: var(--transition); }

/* ===== Hero ===== */
.hero {
  min-height: 100vh;
  background: linear-gradient(135deg, var(--primary) 0%, #0d2b55 40%, #0f3a6e 70%, var(--primary) 100%);
  display: flex; align-items: center; justify-content: center;
  text-align: center; padding: 120px 24px 80px;
  position: relative; overflow: hidden;
}
.hero::before {
  content: ''; position: absolute;
  width: 600px; height: 600px; border-radius: 50%;
  background: radial-gradient(circle, rgba(0,188,212,0.08) 0%, transparent 70%);
  top: -200px; right: -200px;
}
.hero::after {
  content: ''; position: absolute;
  width: 400px; height: 400px; border-radius: 50%;
  background: radial-gradient(circle, rgba(240,192,64,0.06) 0%, transparent 70%);
  bottom: -100px; left: -100px;
}
.hero-content { max-width: 800px; position: relative; z-index: 1; }
.hero h1 {
  font-size: 3.2rem; font-weight: 800; color: var(--white); margin-bottom: 20px;
  letter-spacing: 1px;
}
.hero h1 span { color: var(--accent); }
.hero p {
  font-size: 1.15rem; color: var(--text); margin-bottom: 40px;
  max-width: 600px; margin-left: auto; margin-right: auto;
}
.btn-group { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }
.btn {
  padding: 14px 36px; border-radius: 50px; font-size: 1rem; font-weight: 600;
  text-decoration: none; transition: var(--transition); display: inline-block;
  border: none; cursor: pointer;
}
.btn-primary { background: var(--accent); color: var(--white); }
.btn-primary:hover { background: var(--accent-hover); transform: translateY(-2px); box-shadow: 0 8px 25px rgba(0,188,212,0.3); }
.btn-outline { background: transparent; color: var(--white); border: 2px solid rgba(255,255,255,0.3); }
.btn-outline:hover { border-color: var(--accent); color: var(--accent); transform: translateY(-2px); }

/* ===== Sections ===== */
.section {
  padding: 100px 24px;
  max-width: 1200px; margin: 0 auto;
}
.section-header { text-align: center; margin-bottom: 60px; }
.section-header h2 {
  font-size: 2.2rem; font-weight: 700; color: var(--primary);
  margin-bottom: 12px;
}
.section-header p { color: var(--gray); font-size: 1.05rem; max-width: 600px; margin: 0 auto; }
.section-header .divider {
  width: 60px; height: 3px; background: var(--accent);
  margin: 16px auto; border-radius: 3px;
}

/* ===== Features / Cards ===== */
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 30px; }
.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 30px; }

.card {
  background: var(--white); border-radius: var(--radius); padding: 40px 30px;
  box-shadow: var(--shadow); transition: var(--transition);
  text-align: center;
}
.card:hover { transform: translateY(-5px); box-shadow: 0 12px 40px rgba(0,0,0,0.12); }
.card .icon {
  width: 64px; height: 64px; border-radius: 16px;
  background: linear-gradient(135deg, var(--accent), var(--primary-light));
  display: flex; align-items: center; justify-content: center;
  margin: 0 auto 20px; font-size: 1.8rem;
}
.card h3 { font-size: 1.2rem; color: var(--primary); margin-bottom: 12px; }
.card p { color: var(--gray); font-size: 0.95rem; line-height: 1.6; }

/* ===== Stats ===== */
.stats-bar {
  background: var(--primary);
  padding: 60px 24px;
}
.stats-grid {
  max-width: 1200px; margin: 0 auto;
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 30px; text-align: center;
}
.stat-item h3 { font-size: 2.5rem; color: var(--gold); font-weight: 700; }
.stat-item p { color: var(--text); font-size: 0.95rem; margin-top: 4px; }

/* ===== About ===== */
.about-content { display: grid; grid-template-columns: 1fr 1fr; gap: 60px; align-items: center; }
.about-text h2 { font-size: 2rem; color: var(--primary); margin-bottom: 20px; }
.about-text h2 span { color: var(--accent); }
.about-text p { color: var(--gray); margin-bottom: 16px; font-size: 1rem; }
.about-text ul { list-style: none; margin-top: 20px; }
.about-text ul li {
  padding: 8px 0; color: var(--text-dark);
  display: flex; align-items: center; gap: 10px;
}
.about-text ul li::before { content: '✓'; color: var(--accent); font-weight: 700; }
.about-image {
  background: linear-gradient(135deg, var(--primary), var(--primary-light));
  border-radius: var(--radius); padding: 60px 40px; text-align: center;
  color: var(--white); min-height: 300px;
  display: flex; align-items: center; justify-content: center;
  font-size: 3rem;
}

/* ===== Services ===== */
.bg-alt { background: var(--light-gray); }
.bg-alt .section { padding: 100px 24px; margin: 0 auto; }

.service-card {
  background: var(--white); border-radius: var(--radius);
  overflow: hidden; box-shadow: var(--shadow); transition: var(--transition);
}
.service-card:hover { transform: translateY(-5px); box-shadow: 0 12px 40px rgba(0,0,0,0.12); }
.service-card-body { padding: 30px; }
.service-card-body h3 { font-size: 1.15rem; color: var(--primary); margin-bottom: 10px; }
.service-card-body p { color: var(--gray); font-size: 0.92rem; }
.service-card-tag {
  display: inline-block; padding: 4px 12px; border-radius: 20px;
  background: rgba(0,188,212,0.1); color: var(--accent); font-size: 0.8rem;
  font-weight: 600; margin-bottom: 12px;
}

/* ===== Team ===== */
.team-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.team-card { text-align: center; }
.team-avatar {
  width: 100px; height: 100px; border-radius: 50%;
  background: linear-gradient(135deg, var(--accent), var(--primary-light));
  margin: 0 auto 16px; display: flex; align-items: center; justify-content: center;
  font-size: 2.5rem; color: var(--white);
}
.team-card h4 { font-size: 1rem; color: var(--primary); }
.team-card p { color: var(--gray); font-size: 0.85rem; }

/* ===== Contact ===== */
.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 50px; }
.contact-info h3 { font-size: 1.4rem; color: var(--primary); margin-bottom: 20px; }
.contact-info p { color: var(--gray); margin-bottom: 12px; display: flex; align-items: center; gap: 10px; }
.contact-info .info-item { margin-bottom: 24px; }
.contact-info .info-item strong { display: block; color: var(--primary); margin-bottom: 4px; }

.contact-form { background: var(--white); padding: 40px; border-radius: var(--radius); box-shadow: var(--shadow); }
.form-group { margin-bottom: 20px; }
.form-group label { display: block; margin-bottom: 6px; font-weight: 500; color: var(--text-dark); font-size: 0.95rem; }
.form-group input, .form-group textarea, .form-group select {
  width: 100%; padding: 12px 16px; border: 2px solid var(--light-gray);
  border-radius: 8px; font-size: 0.95rem; font-family: inherit;
  transition: var(--transition); background: var(--bg);
}
.form-group input:focus, .form-group textarea:focus {
  outline: none; border-color: var(--accent); box-shadow: 0 0 0 3px rgba(0,188,212,0.1);
}
.form-group textarea { min-height: 120px; resize: vertical; }
.btn-submit {
  width: 100%; padding: 14px; background: var(--accent); color: var(--white);
  border: none; border-radius: 8px; font-size: 1rem; font-weight: 600;
  cursor: pointer; transition: var(--transition);
}
.btn-submit:hover { background: var(--accent-hover); }

/* ===== Footer ===== */
footer {
  background: var(--primary); color: var(--text); padding: 60px 24px 30px;
}
.footer-grid {
  max-width: 1200px; margin: 0 auto;
  display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 40px;
  margin-bottom: 40px;
}
.footer-col h4 { color: var(--white); font-size: 1.1rem; margin-bottom: 20px; }
.footer-col p { font-size: 0.9rem; line-height: 1.8; }
.footer-col ul { list-style: none; }
.footer-col ul li { margin-bottom: 10px; }
.footer-col ul a { color: var(--text); text-decoration: none; font-size: 0.9rem; transition: var(--transition); }
.footer-col ul a:hover { color: var(--accent); }
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.1); padding-top: 20px;
  text-align: center; font-size: 0.85rem; color: var(--gray);
}

/* ===== Responsive ===== */
@media (max-width: 992px) {
  .grid-3, .team-grid { grid-template-columns: repeat(2, 1fr); }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .about-content { grid-template-columns: 1fr; }
  .contact-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 768px) {
  .hamburger { display: flex; }
  .nav-links {
    display: none; position: absolute; top: 72px; left: 0; right: 0;
    background: var(--primary); flex-direction: column; padding: 20px 24px;
    gap: 16px; box-shadow: 0 10px 30px rgba(0,0,0,0.2);
  }
  .nav-links.open { display: flex; }
  .hero h1 { font-size: 2rem; }
  .hero p { font-size: 1rem; }
  .section-header h2 { font-size: 1.6rem; }
  .grid-3, .grid-2, .team-grid { grid-template-columns: 1fr; }
  .stats-grid { grid-template-columns: 1fr 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
}

@media (max-width: 480px) {
  .hero h1 { font-size: 1.6rem; }
  .stats-grid { grid-template-columns: 1fr; }
  .btn { padding: 12px 24px; font-size: 0.9rem; }
}