/* ========================================
   www.w3seotools.com - Main Stylesheet
   Deep Blue / Teal Theme
   ======================================== */

/* ---------- 1. Reset & Base ---------- */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

/* ---------- 2. CSS Variables ---------- */
:root {
  --primary: #1a56db;
  --primary-dark: #1243af;
  --accent: #0ea5e9;
  --accent-light: #38bdf8;
  --bg: #ffffff;
  --bg-dark: #0f172a;
  --bg-section: #f8fafc;
  --text: #1e293b;
  --text-light: #475569;
  --text-muted: #4a5568;
  --border: #e2e8f0;
  --shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 10px 40px rgba(0, 0, 0, 0.12);
  --radius: 12px;
  --radius-sm: 8px;
  --transition: 0.3s ease;
}

/* ---------- 3. HTML / Body ---------- */
html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', 'Helvetica Neue', Roboto, Arial, sans-serif;
  background-color: var(--bg);
  color: var(--text);
  line-height: 1.6;
  overflow-x: hidden;
}

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

ul {
  list-style: none;
}

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

/* ---------- 4. Container ---------- */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ---------- 5. Main Header ---------- */
#main-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  padding: 16px 0;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: all var(--transition);
}

#main-header.scrolled {
  background: rgba(255, 255, 255, 0.95);
  border-bottom: 1px solid var(--border);
  box-shadow: 0 2px 20px rgba(0, 0, 0, 0.06);
}

#main-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

/* ---------- 6. Logo ---------- */
.logo {
  font-size: 1.6rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.logo span {
  -webkit-text-fill-color: var(--text);
  color: var(--text);
}

/* ---------- 7. Desktop Navigation ---------- */
.desktop-nav {
  display: flex;
  align-items: center;
}

.desktop-nav ul {
  display: flex;
  align-items: center;
  gap: 32px;
}

.nav-link {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-light);
  position: relative;
  padding: 4px 0;
  transition: color var(--transition);
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--primary), var(--accent));
  transition: width var(--transition);
  border-radius: 2px;
}

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

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

/* ---------- 8. Mobile Menu Button ---------- */
.mobile-menu-btn {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  width: 36px;
  height: 36px;
  font-size: 1.5rem;
  color: var(--text);
  z-index: 1100;
  transition: transform 0.3s ease;
}

.mobile-menu-btn.open {
  transform: rotate(90deg);
}



/* ---------- 9. Mobile Menu Container ---------- */
.mobile-menu-container {
  display: none;
  position: fixed;
  inset: 0;
  z-index: 1050;
}

.mobile-menu-container.open {
  display: block;
}

/* ---------- 10. Mobile Menu Overlay ---------- */
.mobile-menu-overlay {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
}

/* ---------- 11. Mobile Menu Content ---------- */
.mobile-menu-content {
  position: relative;
  top: 0;
  right: 0;
  width: 300px;
  max-width: 85vw;
  height: 100%;
  background: var(--bg);
  display: flex;
  flex-direction: column;
  padding: 60px 24px 24px;
  box-shadow: -4px 0 30px rgba(0, 0, 0, 0.1);
  animation: slideInRight 0.3s ease;
}

@keyframes slideInRight {
  from {
    transform: translateX(100%);
  }
  to {
    transform: translateX(0);
  }
}

/* ---------- 12. Mobile Menu Inner ---------- */
.mobile-menu-header {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 4px;
  margin-bottom: 32px;
}

.mobile-menu-logo {
  font-size: 1.3rem;
  font-weight: 800;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.mobile-menu-logo span {
  -webkit-text-fill-color: var(--text);
  color: var(--text);
}

.mobile-menu-tagline {
  font-size: 0.85rem;
  color: var(--text-muted);
}

.mobile-menu-close {
  position: absolute;
  top: 16px;
  right: 16px;
  background: none;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
  color: var(--text);
  padding: 8px;
  border-radius: 50%;
  transition: all var(--transition);
  z-index: 1060;
}

.mobile-menu-close:hover {
  background: rgba(0,0,0,0.05);
}

.mobile-menu-nav {
  display: flex;
  flex-direction: column;
  gap: 4px;
  flex: 1;
}

.mobile-nav-link {
  font-size: 1.1rem;
  font-weight: 500;
  color: var(--text-light);
  padding: 14px 16px;
  border-radius: var(--radius-sm);
  transition: all var(--transition);
}

.mobile-nav-link:hover,
.mobile-nav-link.active {
  background: linear-gradient(135deg, rgba(26, 86, 219, 0.08), rgba(14, 165, 233, 0.08));
  color: var(--primary);
}

.mobile-menu-footer {
  padding-top: 24px;
  border-top: 1px solid var(--border);
  text-align: center;
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* ---------- 13. Hero Section ---------- */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  background: linear-gradient(135deg, #eff6ff 0%, #e0f2fe 30%, #f0f9ff 60%, #ffffff 100%);
  padding: 120px 0 80px;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 600px;
  height: 600px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(14, 165, 233, 0.08), transparent 70%);
  pointer-events: none;
}

.hero::after {
  content: '';
  position: absolute;
  bottom: -30%;
  left: -10%;
  width: 400px;
  height: 400px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(26, 86, 219, 0.06), transparent 70%);
  pointer-events: none;
}

/* ---------- 14. Hero Container ---------- */
.hero-container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
  position: relative;
  z-index: 1;
}

/* ---------- 15. Hero Content ---------- */
.hero-content h1 {
  font-size: 3rem;
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -0.02em;
  margin-bottom: 20px;
  color: var(--text);
}

.hero-content h1 .highlight {
  background: linear-gradient(135deg, var(--primary), var(--accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-content p {
  font-size: 1.15rem;
  color: var(--text-light);
  line-height: 1.7;
  margin-bottom: 32px;
  max-width: 520px;
}

/* ---------- 16. Hero Image ---------- */
.hero-image {
  display: flex;
  justify-content: center;
  align-items: center;
}

.hero-image img {
  width: 100%;
  max-width: 540px;
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
  transition: transform var(--transition);
}

.hero-image img:hover {
  transform: translateY(-4px);
}

/* ---------- 17. Hero Buttons ---------- */
.hero-buttons {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 32px;
  font-size: 1rem;
  font-weight: 600;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition);
  border: 2px solid transparent;
  font-family: inherit;
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: #ffffff;
  border-color: transparent;
  box-shadow: 0 4px 14px rgba(26, 86, 219, 0.25);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(26, 86, 219, 0.35);
}

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

.btn-secondary:hover {
  border-color: var(--primary);
  background: rgba(26, 86, 219, 0.04);
  transform: translateY(-2px);
}

/* ---------- 18. Section ---------- */
.section {
  padding: 100px 0;
  overflow: hidden;
}

.section:nth-child(even) {
  background: var(--bg-section);
}

/* section:last-of-type removed — caused FAQ text/background color conflict */

/* ---------- 19. Section Title ---------- */
.section-title {
  text-align: center;
  margin-bottom: 60px;
}

.section-title h2 {
  font-size: 2.2rem;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 12px;
  letter-spacing: -0.01em;
}

.section-title p {
  font-size: 1.05rem;
  color: var(--text);
  max-width: 600px;
  margin: 0 auto;
  opacity: 0.65;
}

.section-dark .section-title h2 {
  color: #ffffff;
}

.section-dark .section-title p {
  color: var(--text-muted);
}

/* ---------- 20. Services Grid ---------- */
.services-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 24px;
}

/* ---------- 21. Service Item ---------- */
.service-item {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px 24px;
  transition: all var(--transition);
  cursor: default;
}

.service-item:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: transparent;
}

/* ---------- 22. Service Icon ---------- */
.service-icon {
  width: 56px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  background: linear-gradient(135deg, rgba(26, 86, 219, 0.1), rgba(14, 165, 233, 0.1));
  color: var(--primary);
  font-size: 1.5rem;
  margin-bottom: 20px;
  transition: all var(--transition);
}

.service-item:hover .service-icon {
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: #ffffff;
}

/* ---------- 23. Service Content ---------- */
.service-content h3 {
  font-size: 1.2rem;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--text);
}

.service-content p {
  font-size: 0.95rem;
  color: var(--text-light);
  line-height: 1.6;
}

/* ---------- 24. Content Grid ---------- */
.content-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

/* ---------- 25. Content Card ---------- */
.content-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 24px;
  transition: all var(--transition);
}

.content-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow);
  border-color: transparent;
}

.content-card .service-icon {
  width: 48px;
  height: 48px;
  font-size: 1.25rem;
  margin-bottom: 16px;
}

.content-card h3 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 8px;
}

.content-card p {
  font-size: 0.9rem;
  color: var(--text-light);
  line-height: 1.6;
}

/* ---------- 26. App Guide Section ---------- */
.app-guide {
  background: var(--bg-dark);
  color: #ffffff;
}

.app-guide .section-title h2 {
  color: #ffffff;
}

.app-guide .section-title p {
  color: rgba(255, 255, 255, 0.55);
}

/* ---------- 27. App Container ---------- */
.app-container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}

/* ---------- 28. App Image ---------- */
.app-image {
  display: flex;
  justify-content: center;
}

.app-image img {
  max-width: 400px;
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
}

/* ---------- 29. App Steps ---------- */
.app-steps {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.app-step {
  display: flex;
  gap: 16px;
  align-items: flex-start;
}

.step-number {
  flex-shrink: 0;
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: #ffffff;
  font-weight: 700;
  font-size: 1rem;
}

.app-step-content h4 {
  font-size: 1.05rem;
  font-weight: 600;
  margin-bottom: 4px;
  color: #ffffff;
}

.app-step-content p {
  font-size: 0.92rem;
  color: rgba(255, 255, 255, 0.6);
  line-height: 1.6;
}

/* ---------- 30. FAQ Container ---------- */
.faq-container {
  max-width: 720px;
  margin: 0 auto;
}

/* ---------- 31. FAQ Item ---------- */
.faq-item {
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  margin-bottom: 12px;
  overflow: hidden;
  transition: box-shadow var(--transition);
}

.faq-item:hover {
  box-shadow: var(--shadow);
}

/* ---------- 32. FAQ Question ---------- */
.faq-question {
  width: 100%;
  padding: 18px 24px;
  background: var(--bg);
  border: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
  font-size: 1rem;
  font-weight: 500;
  color: var(--text);
  text-align: left;
  font-family: inherit;
  transition: background var(--transition);
}

.faq-question::after {
  content: '+';
  font-size: 1.3rem;
  color: var(--primary);
  font-weight: 600;
  transition: transform var(--transition);
}

.faq-question.open::after {
  content: '−';
}

.faq-question:hover {
  background: #f1f5f9;
}

/* ---------- 33. FAQ Answer ---------- */
.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s ease, padding 0.35s ease;
}

.faq-answer.open {
  max-height: 300px;
}

.faq-answer p {
  padding: 0 24px 18px;
  color: var(--text);
  font-size: 0.95rem;
  line-height: 1.7;
  opacity: 0.75;
}

/* ---------- 34. Footer ---------- */
footer {
  background: var(--bg-dark);
  color: #ffffff;
  padding: 60px 0 0;
}

/* ---------- 35. Footer Container ---------- */
.footer-container {
  display: grid;
  grid-template-columns: 2fr 1fr;
  gap: 48px;
  padding-bottom: 40px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.footer-logo {
  font-size: 1.5rem;
  font-weight: 800;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 12px;
  display: inline-block;
}

.footer-description {
  font-size: 0.92rem;
  color: rgba(255, 255, 255, 0.6);
  line-height: 1.7;
  max-width: 400px;
}

.footer-links h4 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 16px;
  color: #ffffff;
}

.footer-links ul {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-links a {
  font-size: 0.9rem;
  color: rgba(255, 255, 255, 0.5);
  transition: color var(--transition);
}

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

.copyright {
  text-align: center;
  padding: 20px 0;
  font-size: 0.85rem;
  color: rgba(255, 255, 255, 0.4);
}

/* ---------- 36. Keywords & Highlights ---------- */
.keyword {
  display: inline-block;
  padding: 2px 10px;
  border-radius: 20px;
  background: rgba(26, 86, 219, 0.08);
  color: var(--primary);
  font-weight: 500;
  font-size: 0.9rem;
}

.app-guide .keyword,
footer .keyword {
  background: rgba(255, 255, 255, 0.12);
  color: var(--accent);
}


.highlight {
  background: linear-gradient(135deg, var(--primary), var(--accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  font-weight: 700;
}

.app-guide .highlight,
footer .highlight {
  background: linear-gradient(135deg, var(--accent), #fff);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* ---------- 37. Responsive Media Queries ---------- */

/* Tablet */
@media (max-width: 1024px) {
  .hero-container {
    gap: 40px;
  }

  .hero-content h1 {
    font-size: 2.5rem;
  }

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

  .app-container {
    gap: 40px;
  }
}

@media (max-width: 900px) {
  .hero-container {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .hero-content p {
    margin: 0 auto 32px;
  }

  .hero-buttons {
    justify-content: center;
  }

  .hero-image {
    order: -1;
  }

  .hero-image img {
    max-width: 400px;
  }

  .section {
    padding: 70px 0;
  }

  .section-title h2 {
    font-size: 1.8rem;
  }

  .app-container {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .app-step {
    flex-direction: column;
    align-items: center;
    text-align: center;
  }

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

  .footer-description {
    margin: 0 auto;
  }
}

/* Mobile */
@media (max-width: 768px) {
  .desktop-nav {
    display: none;
  }

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

  .hero {
    min-height: auto;
    padding: 100px 0 60px;
  }

  .hero-content h1 {
    font-size: 2rem;
  }

  .hero-content p {
    font-size: 1rem;
  }

  .hero-buttons {
    flex-direction: column;
    align-items: center;
  }

  .btn {
    width: 100%;
    max-width: 320px;
  }

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

  .services-grid {
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  }

  .faq-question {
    font-size: 0.95rem;
    padding: 16px 18px;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 16px;
  }

  .hero-content h1 {
    font-size: 1.7rem;
  }

  .section-title h2 {
    font-size: 1.5rem;
  }

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

  .hero-image img {
    max-width: 300px;
  }

  .app-image img {
    max-width: 280px;
  }

  .mobile-menu-content {
    width: 100%;
    max-width: 100vw;
  }
}

/* ---------- 38. Animations ---------- */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeIn {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

/* ---------- 39. Scroll Animation Class ---------- */
.animate {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.animate.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ---------- 40. Navbar Scrolled Shadow ---------- */
#main-header.scrolled {
  box-shadow: 0 2px 24px rgba(0, 0, 0, 0.08);
  border-bottom: 1px solid var(--border);
}

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

.mt-1 { margin-top: 8px; }
.mt-2 { margin-top: 16px; }
.mt-3 { margin-top: 24px; }
.mt-4 { margin-top: 32px; }
.mb-1 { margin-bottom: 8px; }
.mb-2 { margin-bottom: 16px; }
.mb-3 { margin-bottom: 24px; }
.mb-4 { margin-bottom: 32px; }