body {
      font-family: 'Inter', sans-serif;
      background-color: #f9fafb;
    }
    /* Scroll Animation */
    .animate-on-scroll {
      opacity: 0;
      transform: translateY(30px);
      transition: opacity 0.6s ease-out, transform 0.6s ease-out;
      will-change: opacity, transform;
    }
    .animate-on-scroll.visible {
      opacity: 1;
      transform: translateY(0);
    }
    /* Header-specific styles to ensure no animations */
    #header {
      animation: none !important;
      transition: none !important;
      opacity: 1;
      transform: none;
    }
    /* Hamburger/Close Icon Styles */
    .hamburger, .close {
      transition: opacity 0.3s ease;
    }
    .hamburger {
      opacity: 1;
    }
    .hamburger.hidden {
      opacity: 0;
      display: none;
    }
    .close {
      opacity: 0;
      display: none;
    }
    .close.active {
      opacity: 1;
      display: block;
    }
    /* Mobile Menu Animations */
    #mobile-menu.hidden {
      opacity: 0;
      transform: translateY(-10px);
      pointer-events: none;
    }
    #mobile-menu:not(.hidden) {
      opacity: 1;
      transform: translateY(0);
      pointer-events: auto;
    }
    .menu-item {
      opacity: 0;
      transform: translateY(20px);
      transition: opacity 0.3s ease, transform 0.3s ease;
    }
    #mobile-menu:not(.hidden) .menu-item {
      opacity: 1;
      transform: translateY(0);
    }
    #mobile-menu:not(.hidden) .menu-item:nth-child(1) { transition-delay: 0.1s; }
    #mobile-menu:not(.hidden) .menu-item:nth-child(2) { transition-delay: 0.2s; }
    #mobile-menu:not(.hidden) .menu-item:nth-child(3) { transition-delay: 0.3s; }
    #mobile-menu:not(.hidden) .menu-item:nth-child(4) { transition-delay: 0.4s; }
    #mobile-menu:not(.hidden) .menu-item:nth-child(5) { transition-delay: 0.5s; }
    /* Back to Top Button Styles */
    #back-to-top {
      position: fixed;
      bottom: 20px;
      right: 20px;
      background-color: #1e3a8a;
      color: #ffffff;
      padding: 0.75rem;
      border-radius: 50%;
      box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
      opacity: 0;
      visibility: hidden;
      transition: opacity 0.3s ease, visibility 0.3s ease, transform 0.3s ease;
      z-index: 1000;
    }
    #back-to-top.visible {
      opacity: 1;
      visibility: visible;
    }
    #back-to-top:hover {
      background-color: #2563eb;
      transform: scale(1.1);
      animation: pulse 1.5s infinite;
    }
    #back-to-top svg {
      width: 24px;
      height: 24px;
    }
    @keyframes pulse {
      0% { transform: scale(1.1); }
      50% { transform: scale(1.15); }
      100% { transform: scale(1.1); }
    }
    @media (max-width: 768px) {
      #back-to-top {
        bottom: 15px;
        right: 15px;
        padding: 0.5rem;
      }
      #back-to-top svg {
        width: 20px;
        height: 20px;
      }
    }
    @media (max-width: 480px) {
      #back-to-top {
        bottom: 10px;
        right: 10px;
        padding: 0.5rem;
      }
      #back-to-top svg {
        width: 18px;
        height: 18px;
      }
    }
    /* Hero Section */
    .hero {
      background: linear-gradient(135deg, #3b82f6 0%, #1e3a8a 100%);
      color: #ffffff;
      position: relative;
      overflow: hidden;
      padding: 5rem 0;
    }
    .hero::before {
      content: '';
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background: radial-gradient(circle at center, rgba(255, 255, 255, 0.1) 0%, transparent 70%);
      z-index: 0;
    }
    .hero .container {
      position: relative;
      z-index: 1;
    }
    .hero h1 {
      font-size: clamp(2rem, 5vw, 3.5rem);
      font-weight: 800;
      line-height: 1.2;
      letter-spacing: -0.025em;
      margin-bottom: 1.5rem;
    }
    .hero p {
      font-size: clamp(1.125rem, 2.5vw, 1.5rem);
      font-weight: 400;
      line-height: 1.6;
      opacity: 0.9;
      margin-bottom: 2rem;
    }
    .hero .button-group a {
      padding: 0.875rem 2rem;
      font-size: clamp(0.875rem, 2vw, 1.125rem);
      font-weight: 600;
      border-radius: 0.75rem;
      transition: all 0.3s ease;
      display: inline-flex;
      align-items: center;
      gap: 0.5rem;
      animation: cta-pulse 2s infinite;
    }
    .hero .button-group a:first-child {
      background-color: #ffffff;
      color: #1e3a8a;
      box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    }
    .hero .button-group a:first-child:hover {
      background-color: #f3f4f6;
      transform: translateY(-3px);
      box-shadow: 0 6px 12px rgba(0, 0, 0, 0.15);
    }
    .hero .button-group a:last-child {
      background-color: transparent;
      border: 2px solid #ffffff;
      color: #ffffff;
    }
    .hero .button-group a:last-child:hover {
      background-color: rgba(255, 255, 255, 0.1);
      transform: translateY(-3px);
      box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    }
    .hero .button-group i {
      font-size: 1.75rem;
    }
    .hero-image-container img {
      width: 100%;
      max-width: clamp(350px, 65vw, 550px);
      height: auto;
      object-fit: contain;
      border-radius: 1rem;
      transition: transform 0.4s ease;
    }
    .hero-image-container img:hover {
      transform: scale(1.05);
    }
    @keyframes cta-pulse {
      0% { transform: scale(1); }
      50% { transform: scale(1.03); }
      100% { transform: scale(1); }
    }
    /* How It Works Section */
    .how-it-works {
      background: linear-gradient(135deg, #f0f7ff 0%, #ffffff 100%);
      padding: 5rem 0;
      position: relative;
    }
    .how-it-works::before {
      content: '';
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background: radial-gradient(circle at 20% 30%, rgba(59, 130, 246, 0.1) 0%, transparent 70%);
      z-index: 0;
    }
    .how-it-works .container {
      position: relative;
      z-index: 1;
    }
    .how-it-works h2 {
      font-size: clamp(2rem, 4.5vw, 3rem);
      font-weight: 800;
      color: #1e3a8a;
      text-align: center;
      margin-bottom: 1.5rem;
      letter-spacing: -0.025em;
    }
    .how-it-works .subtitle {
      font-size: clamp(1rem, 2vw, 1.25rem);
      color: #4b5563;
      text-align: center;
      margin-bottom: 2.5rem;
    }
    .how-it-works .steps-container {
      display: flex;
      justify-content: center;
      gap: 2rem;
      flex-wrap: wrap;
      padding: 0 1rem;
    }
    .how-it-works .step-card {
      flex: 0 1 calc(25% - 2rem);
      background: rgba(255, 255, 255, 0.9);
      backdrop-filter: blur(10px);
      border-radius: 1rem;
      padding: 2rem;
      text-align: center;
      box-shadow: 0 8px 24px rgba(0, 0, 0, 0.1);
      transition: transform 0.4s ease, box-shadow 0.4s ease, background 0.4s ease;
      overflow: hidden;
      position: relative;
      border: 1px solid rgba(255, 255, 255, 0.2);
    }
    .how-it-works .step-card::before {
      content: '';
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background: linear-gradient(135deg, rgba(59, 130, 246, 0.05) 0%, rgba(255, 255, 255, 0.1) 100%);
      z-index: -1;
      transition: opacity 0.4s ease;
      opacity: 0;
    }
    .how-it-works .step-card:hover::before {
      opacity: 1;
    }
    .how-it-works .step-card:hover {
      transform: translateY(-8px) scale(1.02);
      box-shadow: 0 12px 32px rgba(0, 0, 0, 0.15);
      background: rgba(255, 255, 255, 0.95);
    }
    .how-it-works .step-card img {
      width: 100%;
      height: auto;
      max-width: 140px;
      margin-bottom: 1.5rem;
      object-fit: contain;
      transition: transform 0.3s ease;
    }
    .how-it-works .step-card:hover img {
      transform: scale(1.1);
    }
    .how-it-works .step-card h3 {
      font-size: clamp(1.125rem, 2vw, 1.5rem);
      font-weight: 700;
      color: #1e3a8a;
      margin-bottom: 0.75rem;
      letter-spacing: -0.02em;
    }
    .how-it-works .step-card p {
      font-size: clamp(0.875rem, 1.5vw, 1rem);
      color: #4b5563;
      line-height: 1.6;
      opacity: 0.9;
    }
    /* Security Features Section */
    .security-features {
      position: relative;
      overflow: hidden;
      background: linear-gradient(135deg, #ffffff 0%, #e6f0fa 100%);
      padding: 5rem 0;
    }
    .security-features::before {
      content: '';
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background: radial-gradient(circle at 80% 20%, rgba(59, 130, 246, 0.1) 0%, transparent 70%);
      z-index: 0;
    }
    .security-features .container {
      position: relative;
      z-index: 1;
    }
    .security-features h2 {
      font-size: clamp(2rem, 4.5vw, 3rem);
      font-weight: 800;
      color: #1e3a8a;
      text-align: center;
      margin-bottom: 1.5rem;
      letter-spacing: -0.025em;
    }
    .security-features .subtitle {
      font-size: clamp(1rem, 2vw, 1.25rem);
      color: #4b5563;
      text-align: center;
      margin-bottom: 2.5rem;
    }
    .security-features .security-content {
      background: rgba(255, 255, 255, 0.9);
      backdrop-filter: blur(10px);
      border-radius: 1rem;
      padding: 2rem;
      box-shadow: 0 8px 24px rgba(0, 0, 0, 0.1);
      transition: transform 0.3s ease, box-shadow 0.3s ease;
    }
    .security-features .security-content:hover {
      transform: translateY(-5px);
      box-shadow: 0 12px 32px rgba(0, 0, 0, 0.15);
    }
    .security-features .security-content p {
      font-size: clamp(0.875rem, 1.5vw, 1.125rem);
      color: #4b5563;
      line-height: 1.7;
      text-align: left;
    }
    .security-features .security-image-container img {
      width: 100%;
      max-width: clamp(350px, 65vw, 550px);
      height: auto;
      object-fit: contain;
      border-radius: 1rem;
      transition: transform 0.4s ease;
    }
    .security-features .security-image-container img:hover {
      transform: scale(1.05);
    }
    /* Why Choose BillVers Section */
    .why-choose-billvers {
      background: linear-gradient(135deg, #ffffff 0%, #e6f0fa 100%);
      padding: 5rem 0;
      position: relative;
    }
    .why-choose-billvers::before {
      content: '';
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      background: radial-gradient(circle at 20% 30%, rgba(59, 130, 246, 0.05) 0%, transparent 70%);
      z-index: 0;
    }
    .why-choose-billvers .container {
      position: relative;
      z-index: 1;
    }
    .why-choose-billvers h2 {
      font-size: clamp(2.25rem, 4.5vw, 3.25rem);
      font-weight: 800;
      color: #1e3a8a;
      text-align: center;
      margin-bottom: 2.5rem;
      letter-spacing: -0.025em;
    }
    .why-choose-billvers .features-container {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
      gap: 2rem;
      margin-bottom: 3rem;
    }
    .why-choose-billvers .feature-card {
      background: rgba(255, 255, 255, 0.9);
      backdrop-filter: blur(10px);
      border-radius: 1rem;
      padding: 2rem;
      box-shadow: 0 8px 24px rgba(0, 0, 0, 0.1);
      transition: transform 0.3s ease, box-shadow 0.3s ease;
      text-align: left;
      border: 1px solid rgba(255, 255, 255, 0.2);
    }
    .why-choose-billvers .feature-card:hover {
      transform: translateY(-5px);
      box-shadow: 0 12px 32px rgba(0, 0, 0, 0.15);
    }
    .why-choose-billvers .feature-card i {
      font-size: 3rem;
      color: #1e3a8a;
      margin-bottom: 1.25rem;
      transition: transform 0.3s ease;
    }
    .why-choose-billvers .feature-card:hover i {
      transform: scale(1.1);
    }
    .why-choose-billvers .feature-card h3 {
      font-size: clamp(1.25rem, 2.5vw, 1.75rem);
      font-weight: 700;
      color: #1e3a8a;
      margin-bottom: 0.75rem;
    }
    .why-choose-billvers .feature-card p {
      font-size: clamp(0.875rem, 1.5vw, 1.125rem);
      color: #4b5563;
      line-height: 1.6;
    }
    .why-choose-billvers .download-section {
      text-align: center;
      margin-top: 3rem;
      background: linear-gradient(135deg, #3b82f6 0%, #1e3a8a 100%);
      color: #ffffff;
      padding: 2.5rem;
      border-radius: 1rem;
      box-shadow: 0 8px 24px rgba(0, 0, 0, 0.2);
    }
    .why-choose-billvers .download-section h3 {
      font-size: clamp(1.5rem, 2.5vw, 2rem);
      font-weight: 700;
      color: #ffffff;
      margin-bottom: 1.25rem;
    }
    .why-choose-billvers .download-section p {
      font-size: clamp(1rem, 1.5vw, 1.25rem);
      color: #ffffff;
      margin-bottom: 2rem;
    }
    .why-choose-billvers .download-section img {
      width: 100%;
      max-width: clamp(350px, 65vw, 650px);
      height: auto;
      object-fit: contain;
      border-radius: 1rem;
      margin-bottom: 2rem;
      transition: transform 0.4s ease;
    }
    .why-choose-billvers .download-section img:hover {
      transform: scale(1.05);
    }
    .why-choose-billvers .button-group {
      display: flex;
      gap: 1.5rem;
      justify-content: center;
      flex-wrap: wrap;
    }
    .why-choose-billvers .button-group a {
      padding: 0.875rem 2rem;
      font-size: clamp(0.875rem, 2vw, 1.125rem);
      font-weight: 600;
      border-radius: 0.75rem;
      transition: all 0.3s ease;
      display: inline-flex;
      align-items: center;
      gap: 0.5rem;
      animation: cta-pulse 2s infinite;
    }
    .why-choose-billvers .button-group a:first-child {
      background-color: #ffffff;
      color: #1e3a8a;
      box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    }
    .why-choose-billvers .button-group a:first-child:hover {
      background-color: #f3f4f6;
      transform: translateY(-3px);
      box-shadow: 0 6px 12px rgba(0, 0, 0, 0.15);
    }
    .why-choose-billvers .button-group a:last-child {
      background-color: transparent;
      border: 2px solid #ffffff;
      color: #ffffff;
    }
    .why-choose-billvers .button-group a:last-child:hover {
      background-color: rgba(255, 255, 255, 0.1);
      transform: translateY(-3px);
      box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    }
    .why-choose-billvers .button-group i {
      font-size: 1.75rem;
    }
    @media (max-width: 1024px) {
      .why-choose-billvers .features-container {
        grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
      }
    }
    @media (max-width: 768px) {
      .hero {
        padding: 3rem 0;
        text-align: center;
      }
      .hero .button-group {
        flex-direction: row;
        flex-wrap: wrap;
        gap: 1rem;
        justify-content: center;
      }
      .hero-image-container img {
        max-width: clamp(300px, 80vw, 450px);
      }
      .how-it-works {
        padding: 3rem 0;
      }
      .how-it-works .step-card {
        flex: 0 1 calc(50% - 1rem);
        margin-bottom: 1.5rem;
      }
      .how-it-works .steps-container {
        flex-direction: column;
        align-items: center;
      }
      .how-it-works .step-card img {
        max-width: 120px;
      }
      .security-features {
        padding: 3rem 0;
        text-align: center;
      }
      .security-features .security-content {
        text-align: center;
      }
      .security-features .security-image-container img {
        max-width: clamp(300px, 80vw, 450px);
      }
      .why-choose-billvers {
        padding: 3rem 0;
        text-align: center;
      }
      .why-choose-billvers .feature-card {
        text-align: center;
      }
      .why-choose-billvers .download-section img {
        max-width: clamp(300px, 80vw, 450px);
      }
    }
    @media (max-width: 480px) {
      .container {
        padding-left: 0.75rem;
        padding-right: 0.75rem;
      }
      .hero {
        padding: 2rem 0;
      }
      .hero h1 {
        font-size: clamp(1.75rem, 4vw, 2.5rem);
      }
      .hero p {
        font-size: clamp(0.875rem, 2vw, 1.125rem);
      }
      .hero .button-group a {
        padding: 0.75rem 1.5rem;
        font-size: clamp(0.75rem, 2vw, 0.875rem);
      }
      .hero .button-group i {
        font-size: 1.5rem;
      }
      .hero-image-container img {
        max-width: clamp(250px, 80vw, 400px);
      }
      .how-it-works h2 {
        font-size: clamp(1.75rem, 3.5vw, 2.25rem);
      }
      .how-it-works .subtitle {
        font-size: clamp(0.875rem, 2vw, 1rem);
      }
      .how-it-works .step-card {
        flex: 0 1 100%;
      }
      .how-it-works .step-card img {
        max-width: 100px;
      }
      .how-it-works .step-card h3 {
        font-size: clamp(1rem, 2vw, 1.25rem);
      }
      .security-features h2 {
        font-size: clamp(1.75rem, 3.5vw, 2.25rem);
      }
      .security-features .subtitle {
        font-size: clamp(0.875rem, 2vw, 1rem);
      }
      .security-features .security-content p {
        font-size: clamp(0.75rem, 1.5vw, 0.875rem);
      }
      .security-features .security-image-container img {
        max-width: clamp(250px, 80vw, 400px);
      }
      .why-choose-billvers h2 {
        font-size: clamp(1.75rem, 3.5vw, 2.5rem);
      }
      .why-choose-billvers .feature-card i {
        font-size: 2.5rem;
      }
      .why-choose-billvers .feature-card h3 {
        font-size: clamp(1rem, 2vw, 1.25rem);
      }
      .why-choose-billvers .download-section img {
        max-width: clamp(250px, 80vw, 400px);
      }
      .why-choose-billvers .button-group a {
        padding: 0.75rem 1.5rem;
        font-size: clamp(0.75rem, 2vw, 0.875rem);
      }
      .why-choose-billvers .button-group i {
        font-size: 1.5rem;
      }
    }