:root {
  --color-primary: #1a56db;
  --color-primary-dark: #1e429f;
  --color-primary-light: #3b82f6;
  --color-secondary: #06b6d4;
  --color-accent: #f59e0b;
  --color-success: #10b981;
  --color-warning: #f59e0b;
  --color-danger: #ef4444;
  --color-text-primary: #1e293b;
  --color-text-secondary: #64748b;
  --color-text-muted: #94a3b8;
  --color-bg-primary: #ffffff;
  --color-bg-secondary: #f8fafc;
  --color-bg-tertiary: #f1f5f9;
  --color-border: #e2e8f0;
  --color-border-light: #f1f5f9;
  --font-sans: 'PingFang SC', 'Microsoft YaHei', 'Hiragino Sans GB', sans-serif;
  --font-mono: 'SF Mono', 'Fira Code', 'Consolas', monospace;
  --shadow-sm: 0 1px 2px 0 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-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-full: 9999px;
  --transition-fast: 150ms ease;
  --transition-normal: 300ms ease;
  --transition-slow: 500ms ease;
  --container-max: 1200px;
  --nav-height: 72px;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.6;
  color: var(--color-text-primary);
  background-color: var(--color-bg-primary);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a {
  color: inherit;
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--color-primary);
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  outline: none;
  background: none;
}

input, textarea, select {
  font-family: inherit;
  font-size: inherit;
  outline: none;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 12px 16px;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

input:focus, textarea:focus, select:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(26, 86, 219, 0.1);
}

.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 24px;
}

.section {
  padding: 80px 0;
}

.section-bg {
  background-color: var(--color-bg-secondary);
}

.section-title {
  font-size: 36px;
  font-weight: 700;
  text-align: center;
  margin-bottom: 16px;
  color: var(--color-text-primary);
}

.section-subtitle {
  font-size: 18px;
  text-align: center;
  color: var(--color-text-secondary);
  margin-bottom: 60px;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 32px;
  font-size: 16px;
  font-weight: 600;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-fast);
  text-decoration: none;
  white-space: nowrap;
}

.btn-primary {
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-light) 100%);
  color: #fff;
  box-shadow: 0 4px 14px 0 rgba(26, 86, 219, 0.39);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px 0 rgba(26, 86, 219, 0.5);
  color: #fff;
}

.btn-secondary {
  background: #fff;
  color: var(--color-primary);
  border: 2px solid var(--color-primary);
}

.btn-secondary:hover {
  background: var(--color-primary);
  color: #fff;
}

.btn-accent {
  background: linear-gradient(135deg, #f59e0b 0%, #f97316 100%);
  color: #fff;
  box-shadow: 0 4px 14px 0 rgba(245, 158, 11, 0.39);
}

.btn-accent:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px 0 rgba(245, 158, 11, 0.5);
  color: #fff;
}

.btn-lg {
  padding: 18px 40px;
  font-size: 18px;
}

.btn-sm {
  padding: 10px 20px;
  font-size: 14px;
}

.card {
  background: #fff;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-normal);
}

.card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-4px);
}

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

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

.grid {
  display: grid;
  gap: 24px;
}

.grid-2 {
  grid-template-columns: repeat(2, 1fr);
}

.grid-3 {
  grid-template-columns: repeat(3, 1fr);
}

.grid-4 {
  grid-template-columns: repeat(4, 1fr);
}

.grid-6 {
  grid-template-columns: repeat(6, 1fr);
}

.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.mt-1 { margin-top: 8px; }
.mt-2 { margin-top: 16px; }
.mt-3 { margin-top: 24px; }
.mt-4 { margin-top: 32px; }
.mt-5 { margin-top: 48px; }
.mt-6 { margin-top: 64px; }

.mb-1 { margin-bottom: 8px; }
.mb-2 { margin-bottom: 16px; }
.mb-3 { margin-bottom: 24px; }
.mb-4 { margin-bottom: 32px; }
.mb-5 { margin-bottom: 48px; }
.mb-6 { margin-bottom: 64px; }

@media (max-width: 1024px) {
  .grid-4 {
    grid-template-columns: repeat(2, 1fr);
  }
  .grid-6 {
    grid-template-columns: repeat(3, 1fr);
  }
  .section-title {
    font-size: 28px;
  }
  .section {
    padding: 60px 0;
  }
}

@media (max-width: 768px) {
  .grid-2,
  .grid-3,
  .grid-4,
  .grid-6 {
    grid-template-columns: 1fr;
  }
  .section-title {
    font-size: 24px;
  }
  .section-subtitle {
    font-size: 16px;
  }
  .section {
    padding: 48px 0;
  }
  .btn {
    padding: 12px 24px;
    font-size: 15px;
  }
  .btn-lg {
    padding: 14px 28px;
    font-size: 16px;
  }
}

/* ========== 导航栏 ========== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  z-index: 1000;
  transition: all var(--transition-normal);
  border-bottom: 1px solid transparent;
}

.navbar.scrolled {
  background: rgba(255, 255, 255, 0.98);
  box-shadow: var(--shadow-sm);
  border-bottom-color: var(--color-border-light);
}

.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 22px;
  font-weight: 700;
  color: var(--color-text-primary);
}

.nav-logo:hover {
  color: var(--color-primary);
}

.logo-icon {
  font-size: 28px;
}

.logo-text {
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-secondary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav-item {
  padding: 8px 16px;
  font-size: 15px;
  font-weight: 500;
  color: var(--color-text-secondary);
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
  position: relative;
}

.nav-item:hover {
  color: var(--color-primary);
  background: var(--color-bg-tertiary);
}

.nav-item.active {
  color: var(--color-primary);
}

.nav-item.active::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 50%;
  transform: translateX(-50%);
  width: 20px;
  height: 3px;
  background: var(--color-primary);
  border-radius: 2px;
}

.nav-cta {
  margin-left: 16px;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 8px;
  cursor: pointer;
}

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

.nav-toggle.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

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

.nav-toggle.active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* ========== 页脚 ========== */
.footer {
  background: #0f172a;
  color: #94a3b8;
  padding: 60px 0 30px;
  margin-top: 0;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 48px;
  margin-bottom: 40px;
}

.footer-brand {
  max-width: 320px;
}

.footer-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 22px;
  font-weight: 700;
  color: #fff;
  margin-bottom: 16px;
}

.footer-logo .logo-text {
  background: linear-gradient(135deg, var(--color-primary-light) 0%, var(--color-secondary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.footer-desc {
  font-size: 14px;
  line-height: 1.7;
  margin-bottom: 20px;
}

.footer-contact {
  font-size: 14px;
  line-height: 2;
}

.footer-contact a {
  color: #94a3b8;
  transition: color var(--transition-fast);
}

.footer-contact a:hover {
  color: var(--color-primary-light);
}

.footer-links h4 {
  color: #fff;
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 20px;
}

.footer-links ul {
  list-style: none;
}

.footer-links li {
  margin-bottom: 12px;
}

.footer-links a {
  color: #94a3b8;
  font-size: 14px;
  transition: color var(--transition-fast);
}

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

.footer-qrcode {
  margin-top: 8px;
}

.qrcode-placeholder {
  width: 120px;
  height: 120px;
  background: rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-md);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  font-size: 12px;
  text-align: center;
  gap: 8px;
}

.qrcode-placeholder span {
  font-size: 36px;
}

.footer-bottom {
  padding-top: 30px;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 13px;
}

.footer-bottom-links {
  display: flex;
  gap: 24px;
}

.footer-bottom-links a {
  color: #64748b;
  transition: color var(--transition-fast);
}

.footer-bottom-links a:hover {
  color: var(--color-primary-light);
}

.footer-beian {
  margin: 0;
}

.footer-beian a {
  color: #64748b;
  text-decoration: none;
  transition: color var(--transition-fast);
}

.footer-beian a:hover {
  color: var(--color-primary-light);
}

.page-content {
  padding-top: var(--nav-height);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.page-main {
  flex: 1;
}

@media (max-width: 1024px) {
  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: 32px;
  }
  .footer-brand {
    grid-column: 1 / -1;
    max-width: 100%;
  }
}

@media (max-width: 768px) {
  .nav-toggle {
    display: flex;
  }
  
  .nav-menu {
    position: fixed;
    top: var(--nav-height);
    left: 0;
    right: 0;
    background: #fff;
    flex-direction: column;
    padding: 20px;
    gap: 12px;
    box-shadow: var(--shadow-lg);
    transform: translateY(-100%);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-normal);
  }
  
  .nav-menu.open {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }
  
  .nav-item {
    width: 100%;
    text-align: center;
    padding: 12px 16px;
  }
  
  .nav-item.active::after {
    display: none;
  }
  
  .nav-cta {
    margin-left: 0;
    width: 100%;
    margin-top: 8px;
  }
  
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 24px;
  }
  
  .footer-bottom {
    flex-direction: column;
    gap: 16px;
    text-align: center;
  }
  
  .footer-bottom-links {
    gap: 16px;
  }
}