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

:root {
  --primary: #1a3a5c;
  --accent:  #e8a020;
  --text:    #2c2c2c;
  --light:   #f5f7fa;
  --white:   #ffffff;
  --border:  #dde3ec;
  --shadow:  0 4px 20px rgba(0,0,0,0.08);
  --radius:  8px;
  --transition: 0.3s ease;
}

html { scroll-behavior: smooth; }

body {
  font-family: 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  color: var(--text);
  line-height: 1.7;
  background: var(--white);
}

.container { max-width: 1100px; margin: 0 auto; padding: 0 24px; }

/* ===== Header / Nav ===== */
#header {
  position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
  background: var(--white);
  box-shadow: 0 2px 12px rgba(0,0,0,0.07);
  transition: var(--transition);
}

.navbar {
  display: flex; align-items: center; justify-content: space-between;
  max-width: 1100px; margin: 0 auto; padding: 0 24px; height: 68px;
}

.logo a { text-decoration: none; }
.logo-text { font-size: 1.3rem; font-weight: 700; color: var(--primary); letter-spacing: 0.5px; }

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

.nav-actions { display: flex; align-items: center; gap: 12px; }

.lang-btn {
  background: var(--primary); color: var(--white);
  border: none; border-radius: 4px; padding: 6px 14px;
  font-size: 0.85rem; font-weight: 600; cursor: pointer;
  transition: background var(--transition);
}
.lang-btn:hover { background: var(--accent); }

.hamburger {
  display: none; background: none; border: none;
  font-size: 1.4rem; cursor: pointer; color: var(--primary);
}

/* ===== Hero ===== */
.hero {
  min-height: 100vh;
  background: linear-gradient(135deg, var(--primary) 0%, #2a5a8c 60%, #1a3a5c 100%);
  display: flex; align-items: center; justify-content: center;
  text-align: center; padding: 100px 24px 60px;
}

.hero-content { max-width: 700px; }
.hero-content h1 {
  font-size: clamp(2rem, 5vw, 3.2rem);
  color: var(--white); font-weight: 700; margin-bottom: 20px;
  line-height: 1.3;
}
.hero-content p {
  font-size: 1.1rem; color: rgba(255,255,255,0.85);
  margin-bottom: 36px; max-width: 560px; margin-left: auto; margin-right: auto;
}

.btn-primary {
  display: inline-block;
  background: var(--accent); color: var(--white);
  padding: 14px 36px; border-radius: var(--radius);
  text-decoration: none; font-weight: 600; font-size: 1rem;
  border: none; cursor: pointer;
  transition: transform var(--transition), box-shadow var(--transition), background var(--transition);
  box-shadow: 0 4px 16px rgba(232,160,32,0.4);
}
.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(232,160,32,0.5);
  background: #d4911a;
}

/* ===== Sections ===== */
.section { padding: 90px 0; }
.section:nth-child(even) { background: var(--light); }

.section-title {
  text-align: center; font-size: 2rem; font-weight: 700;
  color: var(--primary); margin-bottom: 56px; position: relative;
}
.section-title::after {
  content: ''; display: block; width: 56px; height: 3px;
  background: var(--accent); margin: 14px auto 0;
}

/* ===== About ===== */
.about-grid {
  display: grid; grid-template-columns: 1fr 1fr; gap: 60px; align-items: center;
}
.about-text p { font-size: 1.05rem; color: #444; margin-bottom: 32px; }

.stats { display: flex; gap: 32px; }
.stat { text-align: center; }
.stat-num { display: block; font-size: 2rem; font-weight: 700; color: var(--primary); }
.stat-label { font-size: 0.85rem; color: #666; }

.image-placeholder {
  background: var(--border); border-radius: var(--radius);
  height: 300px; display: flex; align-items: center; justify-content: center;
  color: #999; font-size: 0.9rem;
}

/* ===== Services ===== */
.services-grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 28px;
}

.service-card {
  background: var(--white); border-radius: var(--radius);
  padding: 36px 28px; box-shadow: var(--shadow);
  transition: transform var(--transition), box-shadow var(--transition);
  border-top: 3px solid transparent;
}
.service-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 12px 32px rgba(0,0,0,0.12);
  border-top-color: var(--accent);
}
.service-icon { font-size: 2rem; color: var(--accent); margin-bottom: 16px; }
.service-card h3 { font-size: 1.15rem; color: var(--primary); margin-bottom: 12px; }
.service-card p { font-size: 0.95rem; color: #555; }

/* ===== Contact ===== */
.contact-grid {
  display: grid; grid-template-columns: 1fr 1.4fr; gap: 60px; align-items: start;
}

.contact-info { display: flex; flex-direction: column; gap: 28px; }
.info-item { display: flex; gap: 16px; align-items: flex-start; }
.info-icon { font-size: 1.4rem; margin-top: 2px; }
.info-item strong { display: block; color: var(--primary); font-size: 0.95rem; margin-bottom: 4px; }
.info-item p { color: #555; font-size: 0.95rem; }

/* Form */
.contact-form { display: flex; flex-direction: column; gap: 20px; }

.form-group { position: relative; }
.form-group input,
.form-group textarea {
  width: 100%; padding: 16px 14px 8px;
  border: 1.5px solid var(--border); border-radius: var(--radius);
  font-size: 0.95rem; font-family: inherit; background: var(--white);
  transition: border-color var(--transition);
  outline: none; resize: vertical;
}
.form-group input:focus,
.form-group textarea:focus { border-color: var(--primary); }

.form-group label {
  position: absolute; left: 14px; top: 14px;
  font-size: 0.9rem; color: #888;
  transition: all var(--transition); pointer-events: none;
}
.form-group input:focus ~ label,
.form-group input:not(:placeholder-shown) ~ label,
.form-group textarea:focus ~ label,
.form-group textarea:not(:placeholder-shown) ~ label {
  top: 4px; font-size: 0.75rem; color: var(--primary);
}

.form-success {
  color: #2e7d32; font-size: 0.9rem; display: none;
  background: #e8f5e9; padding: 10px 14px; border-radius: var(--radius);
}
.form-success.show { display: block; }

/* ===== Footer ===== */
.footer {
  background: var(--primary); color: rgba(255,255,255,0.7);
  text-align: center; padding: 28px 24px; font-size: 0.9rem;
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
  .nav-links { display: none; flex-direction: column; gap: 0; }
  .nav-links.open {
    display: flex; position: absolute; top: 68px; left: 0; right: 0;
    background: var(--white); box-shadow: var(--shadow); padding: 12px 0;
  }
  .nav-links.open li a { display: block; padding: 12px 24px; }
  .hamburger { display: block; }

  .about-grid,
  .contact-grid { grid-template-columns: 1fr; gap: 36px; }
  .stats { justify-content: space-around; }
}