/* ========================================
   汇付天下4G大机 - 深铁墨蓝灰批售风
   ======================================== */

/* CSS Variables */
:root {
  --hf-iron: #1A2228;
  --hf-iron-light: #2A3238;
  --approve-cyan: #06B6D4;
  --approve-cyan-dark: #0891B2;
  --service-green: #10B981;
  --service-green-dark: #059669;
  --bg-page: #E5E8EB;
  --bg-white: #FFFFFF;
  --text-dark: #080A0D;
  --text-body: #334155;
  --text-light: #64748B;
  --text-muted: #94A3B8;
  --border-light: #E2E8F0;
  
  /* Spacing */
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;
  --space-2xl: 48px;
  --space-3xl: 64px;
  --space-4xl: 96px;
  
  /* Border Radius */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  --radius-2xl: 24px;
  
  /* Shadows */
  --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 -1px rgba(0,0,0,0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.1), 0 4px 6px -2px rgba(0,0,0,0.05);
  --shadow-xl: 0 20px 25px -5px rgba(0,0,0,0.1), 0 10px 10px -5px rgba(0,0,0,0.04);
  --shadow-nav: 0 4px 20px rgba(26,34,40,0.15);
  
  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 200ms ease;
  --transition-slow: 300ms ease;
}

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

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

body {
  font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  background-color: var(--bg-page);
  color: var(--text-body);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

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

ul, ol {
  list-style: none;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.2;
  color: var(--text-dark);
}

.font-dm {
  font-family: 'DM Sans', 'Noto Sans SC', sans-serif;
}

.text-approve {
  color: var(--approve-cyan);
}

.text-service {
  color: var(--service-green);
}

/* Container */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--space-lg);
}

/* ========================================
   Navigation
   ======================================== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: var(--bg-white);
  transition: box-shadow var(--transition-base);
}

.navbar.scrolled {
  box-shadow: var(--shadow-nav);
}

.navbar-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--space-lg);
}

.navbar-logo {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-size: 20px;
  font-weight: 700;
  color: var(--hf-iron);
}

.navbar-logo .logo-icon {
  width: 36px;
  height: 36px;
  background: linear-gradient(135deg, var(--approve-cyan), var(--service-green));
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-weight: 700;
  font-size: 18px;
}

.navbar-nav {
  display: flex;
  align-items: center;
  gap: var(--space-xl);
}

.navbar-nav a {
  color: var(--text-body);
  font-weight: 500;
  transition: color var(--transition-fast);
  position: relative;
}

.navbar-nav a::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--approve-cyan);
  transition: width var(--transition-base);
}

.navbar-nav a:hover,
.navbar-nav a.active {
  color: var(--hf-iron);
}

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

.navbar-cta {
  background: linear-gradient(135deg, var(--approve-cyan), var(--approve-cyan-dark));
  color: white;
  padding: var(--space-sm) var(--space-lg);
  border-radius: var(--radius-md);
  font-weight: 600;
  transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.navbar-cta:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(6,182,212,0.3);
}

.navbar-cta::after {
  display: none;
}

/* Mobile Menu */
.navbar-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--space-sm);
}

.navbar-toggle span {
  width: 24px;
  height: 2px;
  background: var(--hf-iron);
  transition: var(--transition-base);
}

@media (max-width: 768px) {
  .navbar-toggle {
    display: flex;
  }
  
  .navbar-nav {
    position: fixed;
    top: 72px;
    left: 0;
    right: 0;
    background: var(--bg-white);
    flex-direction: column;
    padding: var(--space-lg);
    gap: var(--space-md);
    box-shadow: var(--shadow-lg);
    transform: translateY(-100%);
    opacity: 0;
    visibility: hidden;
    transition: var(--transition-base);
  }
  
  .navbar-nav.active {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }
  
  .navbar-cta {
    width: 100%;
    text-align: center;
  }
}

/* ========================================
   Hero Section
   ======================================== */
.hero {
  padding: 160px 0 100px;
  background: linear-gradient(135deg, var(--hf-iron) 0%, var(--hf-iron-light) 100%);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: radial-gradient(ellipse at 30% 50%, rgba(6,182,212,0.15) 0%, transparent 60%);
  pointer-events: none;
}

.hero-label {
  display: inline-block;
  background: rgba(6,182,212,0.15);
  color: var(--approve-cyan);
  padding: var(--space-xs) var(--space-md);
  border-radius: 20px;
  font-size: 14px;
  font-weight: 500;
  margin-bottom: var(--space-lg);
}

.hero h1 {
  font-size: clamp(32px, 5vw, 56px);
  color: white;
  margin-bottom: var(--space-md);
  letter-spacing: -0.02em;
}

.hero-subtitle {
  font-size: clamp(18px, 2.5vw, 24px);
  color: rgba(255,255,255,0.7);
  margin-bottom: var(--space-xl);
  max-width: 600px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: var(--space-md) var(--space-xl);
  border-radius: var(--radius-md);
  font-weight: 600;
  font-size: 16px;
  cursor: pointer;
  transition: var(--transition-base);
  border: none;
}

.btn-primary {
  background: linear-gradient(135deg, var(--approve-cyan), var(--approve-cyan-dark));
  color: white;
  box-shadow: 0 4px 14px rgba(6,182,212,0.3);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(6,182,212,0.4);
}

.btn-outline {
  background: transparent;
  color: white;
  border: 2px solid rgba(255,255,255,0.5);
}

.btn-outline:hover {
  border-color: white;
  background: rgba(255,255,255,0.1);
}

.btn-service {
  background: linear-gradient(135deg, var(--service-green), var(--service-green-dark));
  color: white;
  box-shadow: 0 4px 14px rgba(16,185,129,0.3);
}

.btn-service:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(16,185,129,0.4);
}

/* Hero Animation */
.hero {
  animation: heroFadeIn 0.8s ease-out;
}

@keyframes heroFadeIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ========================================
   Sections
   ======================================== */
.section {
  padding: var(--space-4xl) 0;
}

.section-title {
  font-size: clamp(28px, 4vw, 40px);
  text-align: center;
  margin-bottom: var(--space-xl);
}

.section-subtitle {
  font-size: 18px;
  color: var(--text-light);
  text-align: center;
  max-width: 600px;
  margin: 0 auto var(--space-2xl);
}

/* ========================================
   Feature Cards
   ======================================== */
.feature-cards {
  display: grid;
  gap: var(--space-lg);
}

.feature-card {
  background: var(--bg-white);
  border-radius: var(--radius-xl);
  padding: var(--space-xl);
  box-shadow: var(--shadow-md);
  transition: var(--transition-base);
}

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

.feature-card-icon {
  width: 56px;
  height: 56px;
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
  margin-bottom: var(--space-md);
}

.feature-card-icon.cyan {
  background: rgba(6,182,212,0.1);
  color: var(--approve-cyan);
}

.feature-card-icon.green {
  background: rgba(16,185,129,0.1);
  color: var(--service-green);
}

.feature-card h3 {
  font-size: 20px;
  margin-bottom: var(--space-sm);
}

.feature-card p {
  color: var(--text-light);
  font-size: 15px;
}

.feature-number {
  font-family: 'DM Sans', sans-serif;
  font-size: 48px;
  font-weight: 700;
  line-height: 1;
  margin-bottom: var(--space-sm);
}

.feature-number.cyan {
  color: var(--approve-cyan);
}

.feature-number.green {
  color: var(--service-green);
}

/* Asymmetric Cards */
.cards-asymmetric {
  display: grid;
  grid-template-columns: 1.28fr 1fr;
  gap: var(--space-lg);
}

@media (max-width: 768px) {
  .cards-asymmetric {
    grid-template-columns: 1fr;
  }
}

/* ========================================
   Product Section
   ======================================== */
.product-section {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-2xl);
  align-items: center;
}

@media (max-width: 768px) {
  .product-section {
    grid-template-columns: 1fr;
  }
}

.product-image {
  background: linear-gradient(135deg, var(--hf-iron) 0%, var(--hf-iron-light) 100%);
  border-radius: var(--radius-xl);
  height: 400px;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
}

.product-image::before {
  content: '';
  position: absolute;
  width: 200px;
  height: 200px;
  background: linear-gradient(135deg, var(--approve-cyan), var(--service-green));
  border-radius: 50%;
  opacity: 0.2;
  filter: blur(60px);
}

.product-image-inner {
  width: 160px;
  height: 220px;
  background: var(--hf-iron-light);
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 14px;
  position: relative;
  z-index: 1;
  border: 1px solid rgba(255,255,255,0.1);
}

.product-content h2 {
  font-size: 32px;
  margin-bottom: var(--space-md);
}

.product-content p {
  font-size: 18px;
  color: var(--text-light);
  margin-bottom: var(--space-lg);
}

/* ========================================
   Service Section
   ======================================== */
.service-section {
  text-align: left;
  padding-left: 10%;
}

.service-section h2 {
  font-size: 36px;
  margin-bottom: var(--space-md);
}

.service-section p {
  font-size: 18px;
  color: var(--text-light);
  margin-bottom: var(--space-lg);
  max-width: 500px;
}

.service-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
  margin-bottom: var(--space-xl);
}

.service-item {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-size: 16px;
  color: var(--text-body);
}

.service-item::before {
  content: '✓';
  color: var(--service-green);
  font-weight: 700;
}

/* ========================================
   Comparison Table
   ======================================== */
.comparison-table {
  width: 100%;
  background: var(--bg-white);
  border-radius: var(--radius-xl);
  overflow: hidden;
  box-shadow: var(--shadow-md);
}

.comparison-table table {
  width: 100%;
  border-collapse: collapse;
}

.comparison-table th,
.comparison-table td {
  padding: var(--space-md) var(--space-lg);
  text-align: left;
  border-bottom: 1px solid var(--border-light);
}

.comparison-table th {
  background: var(--hf-iron);
  color: white;
  font-weight: 600;
  font-size: 16px;
}

.comparison-table th:first-child {
  font-size: 14px;
  color: rgba(255,255,255,0.7);
}

.comparison-table td {
  font-size: 15px;
  color: var(--text-body);
}

.comparison-table tr:last-child td {
  border-bottom: none;
}

.comparison-table tr:hover td {
  background: rgba(229,232,235,0.5);
}

.comparison-table .highlight {
  color: var(--approve-cyan);
  font-weight: 600;
}

.comparison-table .highlight-green {
  color: var(--service-green);
  font-weight: 600;
}

.check-icon {
  color: var(--service-green);
  font-weight: 700;
}

.x-icon {
  color: var(--text-muted);
}

/* ========================================
   CTA Section
   ======================================== */
.cta-section {
  background: linear-gradient(135deg, var(--hf-iron) 0%, var(--hf-iron-light) 100%);
  padding: var(--space-3xl) 0;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.cta-section::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: radial-gradient(ellipse at 50% 50%, rgba(6,182,212,0.1) 0%, transparent 60%);
  pointer-events: none;
}

.cta-section h2 {
  color: white;
  font-size: 32px;
  margin-bottom: var(--space-md);
}

.cta-section p {
  color: rgba(255,255,255,0.7);
  font-size: 18px;
  margin-bottom: var(--space-xl);
}

/* ========================================
   FAQ
   ======================================== */
.faq-list {
  max-width: 800px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.faq-item {
  background: var(--bg-white);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}

.faq-question {
  width: 100%;
  padding: var(--space-lg);
  background: none;
  border: none;
  text-align: left;
  font-size: 16px;
  font-weight: 600;
  color: var(--text-dark);
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--space-md);
  transition: var(--transition-fast);
}

.faq-question:hover {
  color: var(--approve-cyan);
}

.faq-icon {
  font-size: 20px;
  transition: transform var(--transition-base);
}

.faq-item.active .faq-icon {
  transform: rotate(180deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height var(--transition-base);
}

.faq-item.active .faq-answer {
  max-height: 200px;
}

.faq-answer-inner {
  padding: 0 var(--space-lg) var(--space-lg);
  color: var(--text-light);
  line-height: 1.7;
}

/* ========================================
   Footer
   ======================================== */
.footer {
  background: linear-gradient(135deg, var(--hf-iron) 0%, var(--hf-iron-light) 100%);
  padding: var(--space-2xl) 0 var(--space-xl);
  color: white;
}

.footer-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-2xl);
  margin-bottom: var(--space-xl);
}

@media (max-width: 768px) {
  .footer-content {
    grid-template-columns: 1fr;
    gap: var(--space-xl);
  }
}

.footer-section h3 {
  color: white;
  font-size: 18px;
  margin-bottom: var(--space-md);
}

.footer-section p,
.footer-section a {
  color: rgba(255,255,255,0.7);
  font-size: 15px;
  line-height: 1.8;
}

.footer-section a:hover {
  color: var(--approve-cyan);
}

.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.1);
  padding-top: var(--space-lg);
  text-align: center;
  font-size: 13px;
  color: rgba(255,255,255,0.5);
}

/* ========================================
   Hero Variants
   ======================================== */
.hero-cyan {
  background: linear-gradient(135deg, var(--approve-cyan) 0%, var(--approve-cyan-dark) 100%);
}

.hero-cyan::before {
  background: radial-gradient(ellipse at 30% 50%, rgba(255,255,255,0.2) 0%, transparent 60%);
}

.hero-green {
  background: linear-gradient(135deg, var(--service-green) 0%, var(--service-green-dark) 100%);
}

.hero-green::before {
  background: radial-gradient(ellipse at 30% 50%, rgba(255,255,255,0.2) 0%, transparent 60%);
}

.hero-sm {
  padding: 120px 0 60px;
}

/* ========================================
   Feature Grid
   ======================================== */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-lg);
}

@media (max-width: 768px) {
  .feature-grid {
    grid-template-columns: 1fr;
  }
}

.feature-item {
  background: var(--bg-white);
  border-radius: var(--radius-xl);
  padding: var(--space-xl);
  box-shadow: var(--shadow-md);
}

.feature-item-wide {
  grid-column: span 2;
}

@media (max-width: 768px) {
  .feature-item-wide {
    grid-column: span 1;
  }
}

.feature-item-bg {
  background: linear-gradient(135deg, var(--hf-iron) 0%, var(--hf-iron-light) 100%);
  color: white;
}

.feature-item-bg h3,
.feature-item-bg p {
  color: white;
}

.feature-item-bg .feature-number {
  color: var(--approve-cyan);
}

/* ========================================
   Service Promise
   ======================================== */
.service-promise {
  background: rgba(16,185,129,0.05);
  border: 2px solid var(--service-green);
  border-radius: var(--radius-xl);
  padding: var(--space-2xl);
  text-align: center;
  max-width: 800px;
  margin: 0 auto;
}

.service-promise h3 {
  font-size: 24px;
  color: var(--service-green);
  margin-bottom: var(--space-md);
}

.service-promise p {
  font-size: 18px;
  color: var(--text-body);
  margin-bottom: var(--space-lg);
}

.service-promise .answer {
  font-size: 20px;
  font-weight: 700;
  color: var(--service-green);
}

/* ========================================
   Page Header
   ======================================== */
.page-header {
  padding: 140px 0 60px;
  text-align: center;
}

.page-header.hero-cyan {
  padding: 140px 0 80px;
}

.page-header.hero-green {
  padding: 140px 0 80px;
}

.page-header h1 {
  font-size: clamp(32px, 5vw, 48px);
  margin-bottom: var(--space-md);
}

.page-header p {
  font-size: 18px;
  color: rgba(255,255,255,0.8);
  max-width: 600px;
  margin: 0 auto;
}

/* ========================================
   Utility Classes
   ======================================== */
.text-center {
  text-align: center;
}

.mb-lg {
  margin-bottom: var(--space-lg);
}

.mb-xl {
  margin-bottom: var(--space-xl);
}

.mb-2xl {
  margin-bottom: var(--space-2xl);
}

/* ========================================
   Animations
   ======================================== */
@media (prefers-reduced-motion: no-preference) {
  .fade-in {
    animation: fadeIn 0.6s ease-out;
  }
  
  @keyframes fadeIn {
    from {
      opacity: 0;
      transform: translateY(20px);
    }
    to {
      opacity: 1;
      transform: translateY(0);
    }
  }
}

/* ========================================
   Responsive
   ======================================== */
@media (max-width: 768px) {
  .section {
    padding: var(--space-3xl) 0;
  }
  
  .hero {
    padding: 120px 0 60px;
  }
  
  .hero-actions {
    flex-direction: column;
  }
  
  .hero-actions .btn {
    width: 100%;
  }
}