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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', Arial, sans-serif;
  color: #1a2332;
  background: #fff;
  line-height: 1.7;
  overflow-x: hidden;
}

a {
  text-decoration: none;
  color: inherit;
}

img { max-width: 100%; }

.container {
  max-width: 1160px;
  margin: 0 auto;
  padding: 0 24px;
}

.section {
  padding: 88px 0;
}

/* ========== Header / Nav ========== */
.header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  background: rgba(255,255,255,0.96);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(0,0,0,0.07);
  transition: box-shadow 0.3s;
}

.header.scrolled {
  box-shadow: 0 4px 24px rgba(0,60,160,0.08);
}

.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 70px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
}

.logo-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  filter: drop-shadow(0 2px 8px rgba(29,78,216,0.25));
  transition: filter 0.3s;
}

.logo:hover .logo-icon {
  filter: drop-shadow(0 4px 14px rgba(29,78,216,0.45));
}

.logo-text {
  display: flex;
  flex-direction: column;
  line-height: 1.2;
}

.logo-name {
  font-size: 17px;
  font-weight: 700;
  color: #1d4ed8;
  letter-spacing: 1px;
}

.logo-sub {
  font-size: 11px;
  color: #64748b;
  letter-spacing: 0.5px;
}

.nav {
  display: flex;
  gap: 36px;
}

.nav a {
  font-size: 15px;
  font-weight: 500;
  color: #334155;
  position: relative;
  transition: color 0.2s;
}

.nav a::after {
  content: '';
  position: absolute;
  bottom: -4px; left: 0;
  width: 0; height: 2px;
  background: linear-gradient(90deg, #1d4ed8, #0ea5e9);
  border-radius: 2px;
  transition: width 0.3s;
}

.nav a:hover { color: #1d4ed8; }
.nav a:hover::after { width: 100%; }

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.nav-toggle span {
  display: block;
  width: 24px; height: 2px;
  background: #334155;
  border-radius: 2px;
  transition: all 0.3s;
}

.mobile-menu {
  display: none;
  flex-direction: column;
  background: #fff;
  border-top: 1px solid #e2e8f0;
  padding: 8px 0;
}

.mobile-menu a {
  padding: 12px 24px;
  font-size: 15px;
  color: #334155;
  font-weight: 500;
  border-bottom: 1px solid #f1f5f9;
  transition: background 0.2s, color 0.2s;
}

.mobile-menu a:hover {
  background: #f0f4ff;
  color: #1d4ed8;
}

.mobile-menu.open { display: flex; }

/* ========== Buttons ========== */
.btn {
  display: inline-block;
  padding: 13px 32px;
  border-radius: 8px;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.25s;
  border: 2px solid transparent;
}

.btn-primary {
  background: linear-gradient(135deg, #1d4ed8, #0ea5e9);
  color: #fff;
  border-color: transparent;
  box-shadow: 0 4px 18px rgba(29,78,216,0.3);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 28px rgba(29,78,216,0.4);
}

.btn-outline {
  background: transparent;
  color: #fff;
  border-color: rgba(255,255,255,0.7);
}

.btn-outline:hover {
  background: rgba(255,255,255,0.15);
  border-color: #fff;
}

.btn-full { width: 100%; text-align: center; }

/* ========== Hero ========== */
.hero {
  position: relative;
  min-height: 100vh;
  background: linear-gradient(135deg, #0f172a 0%, #1e3a8a 45%, #0369a1 100%);
  display: flex;
  align-items: center;
  overflow: hidden;
  padding-top: 70px;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 60% 60% at 70% 40%, rgba(14,165,233,0.18) 0%, transparent 70%),
    radial-gradient(ellipse 40% 40% at 20% 70%, rgba(99,102,241,0.15) 0%, transparent 60%);
  pointer-events: none;
}

/* Animated dots/grid */
.hero-bg::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image: radial-gradient(rgba(255,255,255,0.07) 1px, transparent 1px);
  background-size: 40px 40px;
}

.hero-content {
  position: relative;
  z-index: 2;
  padding: 80px 24px 120px;
  max-width: 720px;
}

.hero-badge {
  display: inline-block;
  background: rgba(255,255,255,0.12);
  border: 1px solid rgba(255,255,255,0.25);
  color: #bfdbfe;
  font-size: 13px;
  letter-spacing: 3px;
  padding: 6px 18px;
  border-radius: 20px;
  margin-bottom: 28px;
  backdrop-filter: blur(8px);
}

.hero-title {
  font-size: clamp(32px, 5vw, 58px);
  font-weight: 800;
  color: #fff;
  line-height: 1.25;
  margin-bottom: 20px;
  letter-spacing: 2px;
}

.hero-sub {
  font-size: clamp(15px, 2vw, 18px);
  color: #93c5fd;
  margin-bottom: 40px;
  max-width: 520px;
}

.hero-btns {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.hero-wave {
  position: absolute;
  bottom: 0; left: 0; right: 0;
  line-height: 0;
  z-index: 2;
}

.hero-wave svg {
  width: 100%;
  height: 80px;
  display: block;
}

/* ========== Stats ========== */
.stats {
  background: #f4f7fb;
  padding: 48px 0;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.stat-card {
  background: #fff;
  border-radius: 16px;
  padding: 32px 20px;
  text-align: center;
  box-shadow: 0 2px 16px rgba(0,40,120,0.06);
  transition: transform 0.3s, box-shadow 0.3s;
}

.stat-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 32px rgba(29,78,216,0.12);
}

.stat-num {
  font-size: 38px;
  font-weight: 800;
  background: linear-gradient(135deg, #1d4ed8, #0ea5e9);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1.1;
  margin-bottom: 8px;
}

.stat-label {
  font-size: 14px;
  color: #64748b;
  font-weight: 500;
  letter-spacing: 1px;
}

/* ========== About ========== */
.about { background: #fff; }

.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 72px;
  align-items: center;
}

.section-tag {
  display: inline-block;
  background: #eff6ff;
  color: #1d4ed8;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 3px;
  padding: 5px 14px;
  border-radius: 20px;
  margin-bottom: 16px;
  text-transform: uppercase;
}

.section-title {
  font-size: clamp(24px, 3vw, 36px);
  font-weight: 800;
  color: #0f172a;
  line-height: 1.3;
  margin-bottom: 20px;
}

.about-text p {
  color: #475569;
  font-size: 15px;
  margin-bottom: 14px;
}

.about-list {
  list-style: none;
  margin-top: 24px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.about-list li {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  font-size: 14px;
  color: #334155;
}

.check {
  color: #1d4ed8;
  font-weight: 800;
  flex-shrink: 0;
  margin-top: 2px;
}

.about-visual {
  display: flex;
  align-items: center;
  justify-content: center;
}

.about-card-wrap {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  width: 100%;
  max-width: 360px;
}

.about-card {
  background: #fff;
  border-radius: 16px;
  padding: 28px 20px;
  text-align: center;
  font-size: 14px;
  font-weight: 600;
  color: #1e3a8a;
  box-shadow: 0 4px 20px rgba(0,40,120,0.08);
  transition: transform 0.3s, box-shadow 0.3s;
  border: 1.5px solid #e0e7ff;
}

.about-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 10px 30px rgba(29,78,216,0.14);
  border-color: #bfdbfe;
}

.ac-icon {
  font-size: 36px;
  margin-bottom: 10px;
  display: block;
}

.ac1 { background: linear-gradient(135deg, #eff6ff, #dbeafe); }
.ac2 { background: linear-gradient(135deg, #f0fdf4, #dcfce7); }
.ac3 { background: linear-gradient(135deg, #fff7ed, #fed7aa); }
.ac4 { background: linear-gradient(135deg, #fdf4ff, #f3e8ff); }

/* ========== Services ========== */
.services {
  background: #f4f7fb;
}

.section-header {
  text-align: center;
  margin-bottom: 60px;
}

.section-desc {
  color: #64748b;
  font-size: 15px;
  margin-top: 10px;
  max-width: 480px;
  margin-left: auto;
  margin-right: auto;
}

.services-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
  margin-bottom: 52px;
}

.service-card {
  background: #fff;
  border-radius: 18px;
  padding: 36px 28px;
  box-shadow: 0 2px 16px rgba(0,40,120,0.06);
  border: 1.5px solid #e2e8f0;
  transition: transform 0.3s, box-shadow 0.3s, border-color 0.3s;
  position: relative;
  overflow: hidden;
}

.service-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  background: linear-gradient(90deg, #1d4ed8, #0ea5e9);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.3s;
}

.service-card:hover::before { transform: scaleX(1); }

.service-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 12px 36px rgba(29,78,216,0.13);
  border-color: #bfdbfe;
}

.service-icon {
  font-size: 40px;
  margin-bottom: 18px;
  display: block;
}

.service-card h3 {
  font-size: 17px;
  font-weight: 700;
  color: #0f172a;
  margin-bottom: 10px;
}

.service-card p {
  font-size: 14px;
  color: #64748b;
  line-height: 1.75;
}

/* Scope box */
.scope-box {
  background: linear-gradient(135deg, #eff6ff, #e0f2fe);
  border: 1.5px solid #bfdbfe;
  border-radius: 16px;
  padding: 32px 36px;
}

.scope-title {
  font-size: 15px;
  font-weight: 700;
  color: #1d4ed8;
  margin-bottom: 12px;
  letter-spacing: 0.5px;
}

.scope-text {
  font-size: 14px;
  color: #334155;
  line-height: 1.9;
}

.scope-note {
  font-size: 13px;
  color: #64748b;
  margin-top: 10px;
  font-style: italic;
}

/* ========== Contact ========== */
.contact { background: #fff; }

.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: flex-start;
}

.contact-info {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.contact-item {
  display: flex;
  align-items: flex-start;
  gap: 18px;
  background: #f8fafc;
  border-radius: 14px;
  padding: 20px 22px;
  border: 1.5px solid #e2e8f0;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.contact-item:hover {
  border-color: #bfdbfe;
  box-shadow: 0 4px 16px rgba(29,78,216,0.07);
}

.contact-icon {
  font-size: 26px;
  flex-shrink: 0;
  margin-top: 2px;
}

.ci-label {
  font-size: 12px;
  color: #94a3b8;
  font-weight: 600;
  letter-spacing: 1px;
  text-transform: uppercase;
  margin-bottom: 4px;
}

.ci-value {
  font-size: 15px;
  color: #1e293b;
  font-weight: 500;
}

/* Form */
.contact-form-wrap {
  background: #f8fafc;
  border-radius: 18px;
  padding: 36px 32px;
  border: 1.5px solid #e2e8f0;
}

.contact-form {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}

.contact-form input,
.contact-form textarea {
  width: 100%;
  padding: 13px 16px;
  border: 1.5px solid #e2e8f0;
  border-radius: 10px;
  font-size: 14px;
  color: #1e293b;
  background: #fff;
  font-family: inherit;
  transition: border-color 0.2s, box-shadow 0.2s;
  outline: none;
  resize: vertical;
}

.contact-form input:focus,
.contact-form textarea:focus {
  border-color: #1d4ed8;
  box-shadow: 0 0 0 3px rgba(29,78,216,0.1);
}

.contact-form input::placeholder,
.contact-form textarea::placeholder {
  color: #94a3b8;
}

/* ========== Footer ========== */
.footer {
  background: #0f172a;
  color: #94a3b8;
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 44px 24px 36px;
  flex-wrap: wrap;
  gap: 24px;
  border-bottom: 1px solid rgba(255,255,255,0.07);
}

.logo-name-f {
  font-size: 16px;
  font-weight: 700;
  color: #fff;
  display: block;
  margin-bottom: 6px;
}

.footer-logo p {
  font-size: 13px;
  color: #475569;
  letter-spacing: 2px;
}

.footer-links {
  display: flex;
  gap: 28px;
  flex-wrap: wrap;
}

.footer-links a {
  font-size: 14px;
  color: #64748b;
  transition: color 0.2s;
}

.footer-links a:hover { color: #93c5fd; }

.footer-bottom {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 24px;
  padding: 18px 24px;
  font-size: 13px;
  color: #475569;
  flex-wrap: wrap;
  text-align: center;
}

.footer-bottom a {
  color: #64748b;
  transition: color 0.2s;
}

.footer-bottom a:hover { color: #93c5fd; }

/* ========== Back to Top ========== */
.back-top {
  position: fixed;
  bottom: 32px;
  right: 32px;
  width: 46px; height: 46px;
  background: linear-gradient(135deg, #1d4ed8, #0ea5e9);
  color: #fff;
  border: none;
  border-radius: 50%;
  font-size: 20px;
  cursor: pointer;
  box-shadow: 0 4px 18px rgba(29,78,216,0.35);
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.3s, transform 0.3s;
  z-index: 999;
}

.back-top.visible {
  opacity: 1;
  transform: translateY(0);
}

.back-top:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 28px rgba(29,78,216,0.45);
}

/* ========== Animations ========== */
.fade-up {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-up.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ========== Responsive ========== */
@media (max-width: 992px) {
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .services-grid { grid-template-columns: repeat(2, 1fr); }
  .about-grid { grid-template-columns: 1fr; gap: 48px; }
  .contact-grid { grid-template-columns: 1fr; gap: 40px; }
}

@media (max-width: 640px) {
  .section { padding: 60px 0; }
  .nav { display: none; }
  .nav-toggle { display: flex; }
  .stats-grid { grid-template-columns: repeat(2, 1fr); gap: 16px; }
  .services-grid { grid-template-columns: 1fr; }
  .form-row { grid-template-columns: 1fr; }
  .hero-btns { flex-direction: column; }
  .footer-inner { flex-direction: column; align-items: flex-start; }
  .about-card-wrap { max-width: 100%; }
  .scope-box { padding: 22px 20px; }
  .contact-form-wrap { padding: 24px 20px; }
  .footer-bottom { flex-direction: column; gap: 8px; }
}