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

:root {
  --color-primary: #2563eb;
  --color-primary-dark: #1d4ed8;
  --color-primary-light: #dbeafe;
  --color-dark: #0f172a;
  --color-gray-900: #1e293b;
  --color-gray-700: #334155;
  --color-gray-500: #64748b;
  --color-gray-300: #cbd5e1;
  --color-gray-100: #f1f5f9;
  --color-gray-50: #f8fafc;
  --color-white: #ffffff;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1);
  --radius: 8px;
  --transition: 0.3s ease;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 80px;
}

body {
  font-family: var(--font-sans);
  color: var(--color-gray-900);
  background: var(--color-white);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

/* ===== Container ===== */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ===== Section ===== */
.section {
  padding: 100px 0;
}

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

.section-tag {
  display: inline-block;
  font-size: 13px;
  font-weight: 600;
  color: var(--color-primary);
  letter-spacing: 2px;
  text-transform: uppercase;
  margin-bottom: 12px;
}

.section-title {
  font-size: 36px;
  font-weight: 700;
  color: var(--color-dark);
  margin-bottom: 12px;
}

.section-desc {
  font-size: 18px;
  color: var(--color-gray-500);
  max-width: 560px;
  margin: 0 auto;
}

/* ===== Header ===== */
.header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid transparent;
  transition: all var(--transition);
}

.header.scrolled {
  border-bottom-color: var(--color-gray-300);
  box-shadow: var(--shadow-sm);
}

.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 88px;
}

.logo {
  display: inline-flex;
  align-items: center;
}

.logo-img {
  height: 56px;
  width: auto;
}

.logo-img-footer {
  height: 64px;
}

.nav-list {
  display: flex;
  gap: 32px;
}

.nav-link {
  font-size: 15px;
  font-weight: 500;
  color: var(--color-gray-700);
  position: relative;
  transition: color var(--transition);
  padding: 4px 0;
}

.nav-link::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--color-primary);
  transition: width var(--transition);
}

.nav-link:hover,
.nav-link.active {
  color: var(--color-primary);
}

.nav-link:hover::after,
.nav-link.active::after {
  width: 100%;
}

/* 汉堡菜单 */
.menu-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.menu-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-dark);
  border-radius: 2px;
  transition: all var(--transition);
}

.menu-toggle.active span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.menu-toggle.active span:nth-child(2) {
  opacity: 0;
}

.menu-toggle.active span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* ===== Hero ===== */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  overflow: hidden;
  background: linear-gradient(135deg, #f0f5ff 0%, #e8f0fe 50%, #f8fafc 100%);
}

.hero-bg {
  position: absolute;
  top: -50%;
  right: -20%;
  width: 800px;
  height: 800px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(37, 99, 235, 0.08) 0%, transparent 70%);
  pointer-events: none;
}

.hero-content {
  position: relative;
  z-index: 1;
  max-width: 700px;
}

.hero-title {
  font-size: 56px;
  font-weight: 800;
  line-height: 1.15;
  color: var(--color-dark);
  margin-bottom: 24px;
  letter-spacing: -1px;
}

.hero-title .highlight {
  color: var(--color-primary);
}

.hero-subtitle {
  font-size: 20px;
  color: var(--color-gray-500);
  line-height: 1.7;
  margin-bottom: 40px;
}

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

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 32px;
  font-size: 16px;
  font-weight: 600;
  border-radius: var(--radius);
  border: 2px solid transparent;
  cursor: pointer;
  transition: all var(--transition);
  white-space: nowrap;
}

.btn-primary {
  background: var(--color-primary);
  color: var(--color-white);
}

.btn-primary:hover {
  background: var(--color-primary-dark);
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.btn-outline {
  background: transparent;
  color: var(--color-primary);
  border-color: var(--color-primary);
}

.btn-outline:hover {
  background: var(--color-primary);
  color: var(--color-white);
}

/* ===== About ===== */
.about {
  background: var(--color-white);
}

.about-text {
  max-width: 720px;
  margin: 0 auto;
  text-align: center;
}

.about-text p {
  font-size: 16px;
  color: var(--color-gray-500);
  line-height: 1.8;
  margin-bottom: 12px;
}

/* ===== Services ===== */
.services {
  background: var(--color-gray-50);
}

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

.service-card {
  background: var(--color-white);
  padding: 40px 32px;
  border-radius: var(--radius);
  border: 1px solid var(--color-gray-100);
  transition: all var(--transition);
}

.service-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-xl);
  border-color: transparent;
}

.service-icon {
  margin-bottom: 20px;
}

.service-icon svg {
  width: 48px;
  height: 48px;
  display: block;
}

.service-card h3 {
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 12px;
  color: var(--color-dark);
}

.service-card p {
  font-size: 15px;
  color: var(--color-gray-500);
  line-height: 1.7;
}

/* ===== 公众号 / 视频号 ===== */
.social-item {
  margin-top: 8px;
}

.social-qr {
  display: flex;
  align-items: center;
  gap: 16px;
}

.qr-placeholder {
  width: 140px;
  height: 140px;
  border: 2px dashed var(--color-gray-300);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  font-size: 13px;
  color: var(--color-gray-500);
  background: var(--color-gray-50);
  flex-shrink: 0;
}

.qr-placeholder img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  border-radius: var(--radius);
}

.qr-placeholder.has-qr {
  border: 1px solid var(--color-gray-300);
  background: none;
}

.social-hint {
  font-size: 13px;
  color: var(--color-gray-500);
  line-height: 1.5;
}

/* ===== Contact ===== */
.contact {
  background: var(--color-gray-50);
}

.contact-grid {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 60px;
  align-items: start;
}

.contact-form {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}

.contact-form .full-width {
  grid-column: 1 / -1;
}

.form-group label {
  display: block;
  font-size: 14px;
  font-weight: 600;
  color: var(--color-gray-700);
  margin-bottom: 6px;
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 12px 16px;
  font-size: 15px;
  font-family: inherit;
  border: 1px solid var(--color-gray-300);
  border-radius: var(--radius);
  background: var(--color-white);
  color: var(--color-dark);
  transition: border-color var(--transition);
  outline: none;
}

.form-group input:focus,
.form-group textarea:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px var(--color-primary-light);
}

.form-group input::placeholder,
.form-group textarea::placeholder {
  color: var(--color-gray-300);
}

.contact-info {
  display: flex;
  flex-direction: column;
  gap: 28px;
}

.info-item h4 {
  font-size: 14px;
  font-weight: 600;
  color: var(--color-gray-500);
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: 4px;
}

.info-item p {
  font-size: 16px;
  color: var(--color-gray-900);
  font-weight: 500;
}

/* ===== Footer ===== */
.footer {
  background: var(--color-dark);
  color: var(--color-gray-300);
  padding: 60px 0 0;
}

.footer-container {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 48px;
  padding-bottom: 48px;
  border-bottom: 1px solid var(--color-gray-700);
}

.footer-brand .logo {
  display: inline-block;
  margin-bottom: 12px;
  color: var(--color-white);
}

.footer-brand p {
  font-size: 15px;
  color: var(--color-gray-500);
}

.footer-links h4 {
  font-size: 14px;
  font-weight: 600;
  color: var(--color-white);
  text-transform: uppercase;
  letter-spacing: 1px;
  margin-bottom: 16px;
}

.footer-links li {
  margin-bottom: 10px;
}

.footer-links a {
  font-size: 15px;
  color: var(--color-gray-500);
  transition: color var(--transition);
}

.footer-links a:hover {
  color: var(--color-white);
}

.footer-bottom {
  text-align: center;
  padding: 24px 0;
}

.footer-bottom p {
  font-size: 14px;
  color: var(--color-gray-500);
}

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

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

/* ===== Responsive ===== */
@media (max-width: 1024px) {
  .service-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
  .hero-title { font-size: 36px; }
  .hero-subtitle { font-size: 17px; }
  .section-title { font-size: 28px; }
  .section { padding: 64px 0; }

  .menu-toggle { display: flex; }

  .nav {
    position: fixed;
    top: 88px;
    left: 0;
    width: 100%;
    background: var(--color-white);
    padding: 24px;
    border-bottom: 1px solid var(--color-gray-100);
    transform: translateY(-100%);
    opacity: 0;
    pointer-events: none;
    transition: all var(--transition);
  }

  .nav.open {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
  }

  .nav-list {
    flex-direction: column;
    gap: 0;
  }

  .nav-link {
    display: block;
    padding: 12px 0;
    font-size: 17px;
    border-bottom: 1px solid var(--color-gray-100);
  }

  .service-grid { grid-template-columns: 1fr; }

  .contact-grid {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .contact-form { grid-template-columns: 1fr; }

  .footer-container {
    grid-template-columns: 1fr;
    gap: 32px;
  }
}

@media (max-width: 480px) {
  .hero-title { font-size: 30px; }
  .hero-actions { flex-direction: column; }
  .hero-actions .btn { width: 100%; }
}