/* ===== GLOBAL LAYOUT ===== */
    .app-wrapper {
      max-width: 1400px;
      margin: 0 auto;
      padding: 2rem 0;
      text-align: left;
    }

    /* header style */
    .page-header {
      margin-bottom: 2rem;
      text-align: center;
    }
    .page-header h1 {
      font-size: 2rem;
      font-weight: 700;
      background: linear-gradient(135deg, #1e3c72, #2b4e8c);
      background-clip: text;
      -webkit-background-clip: text;
      color: transparent;
      letter-spacing: -0.3px;
    }
    .page-header p {
      color: #2c3e66;
      margin-top: 0.5rem;
      font-weight: 450;
    }

    /* ===== DESKTOP: Sticky Sidebar Menu (hidden on mobile) ===== */
    .desktop-nav {
      position: sticky;
      top: 1.5rem;
      align-self: start;
      background: rgba(255, 255, 255, 0.92);
      backdrop-filter: blur(14px);
      border-radius: 2rem;
      box-shadow: 0 12px 28px rgba(0, 0, 0, 0.05), 0 1px 2px rgba(0, 0, 0, 0.02);
      padding: 0.8rem;
      border: 1px solid rgba(148, 163, 184, 0.25);
      width: 260px;
      transition: all 0.2s;
    }
    .desktop-nav h3 {
      font-size: 1rem;
      font-weight: 600;
      padding: 0 1rem 0.8rem 1rem;
      margin-bottom: 0.5rem;
      border-bottom: 1.5px solid #e2edf2;
      color: #1e2f47;
      display: flex;
      align-items: center;
      gap: 6px;
    }
    .desktop-nav h3::before {
      content: "📍";
      font-size: 1.1rem;
    }
    .nav-list {
      list-style: none;
      display: flex;
      flex-direction: column;
      gap: 0.2rem;
      padding-left: 0;
    }
    .nav-list li a {
      display: block;
      padding: 0.7rem 1rem;
      font-size: 0.92rem;
      font-weight: 500;
      text-decoration: none;
      color: #2c3e50;
      border-radius: 1.2rem;
      transition: all 0.2s ease;
      background: transparent;
    }
    .nav-list li a:hover {
      background: #BBBDBF;
      color: #fff;
      transform: translateX(5px);
    }
    /* active scrollspy style (desktop) */
    .nav-list li a.active {
      background: #4694E0;
      color: white;
      box-shadow: 0 6px 12px -6px rgba(44, 110, 158, 0.4);
      font-weight: 600;
    }

    /* ===== MOBILE SELECT MENU (hidden on desktop) ===== */
    .mobile-select-container {
      display: none;
      margin-bottom: 1.8rem;
      background: white;
      border-radius: 1.75rem;
      padding: 0.25rem;
      box-shadow: 0 4px 12px rgba(0, 0, 0, 0.03), 0 1px 2px rgba(0, 0, 0, 0.05);
      border: 1px solid #dce5ef;
    }
    .mobile-select {
      width: 100%;
      padding: 0.9rem 1.2rem;
      font-size: 1rem;
      font-weight: 500;
      font-family: inherit;
      background: #ffffff;
      border: none;
      border-radius: 1.5rem;
      color: #0f2b3d;
      cursor: pointer;
      outline: none;
      appearance: none;
      background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='20' height='20' viewBox='0 0 24 24' fill='none' stroke='%233b6e9e' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'><polyline points='6 9 12 15 18 9'></polyline></svg>");
      background-repeat: no-repeat;
      background-position: right 1rem center;
      background-size: 1.2rem;
    }
    .mobile-select:focus {
      border: 1px solid #3b82f6;
      box-shadow: 0 0 0 3px rgba(59,130,246,0.2);
    }

    /* ===== MAIN CONTENT STYLES ===== */

    .accordion-button::after {
      font-family: FontAwesome;
      content: "\f078";
      background-image: none;
    }

    .accordion-button:not(.collapsed)::after {
      background-image: none;
    }

    .accordion-button:not(.collapsed) {
      background-color: #007976;
      color: #fff;
    }

    h2.accordion-header  {margin-bottom: 0 !important;border: 0px !important;}

    .accordion-button  {
      background: #00A89C;
      color: #fff;
      font-size: 1.2rem;
    }

    .accordion  {
      margin-top: 15px;
    }
    .accordion-item h2  {
      background: #ddd !important;
      padding: 0 !important;
    }

    .box-t3  {
      border-radius: 2rem;
      box-shadow: 0 12px 28px rgba(0, 0, 0, 0.05), 0 1px 2px rgba(0, 0, 0, 0.02);
      padding: 1.5rem 1.2rem;
      border: 1px solid rgba(148, 163, 184, 0.25);
      background: linear-gradient(225deg, #ffffff 0.000%, #ffffff 25.000%, #ffffff 50.000%, #f3f3ee 75.000%, #d5dadc 100.000%);
    }

    .box-t3 h4  {
      color:#1a1a1a;
      font-size: 18px;
    }

    .box-t2  {
      border-radius: 2rem;
      box-shadow: 0 12px 28px rgba(0, 0, 0, 0.05), 0 1px 2px rgba(0, 0, 0, 0.02);
      padding: 1.5rem 1.2rem;
      border: 1px solid rgba(148, 163, 184, 0.25);
      text-align: center;
    }

    .box-t2 h4  {
      color:#4694E0;
    }

    .box-t1  {
      border-radius: 2rem;
      box-shadow: 0 12px 28px rgba(0, 0, 0, 0.05), 0 1px 2px rgba(0, 0, 0, 0.02);
      padding: 0.4rem 1.2rem;
      border: 1px solid rgba(148, 163, 184, 0.25);
    }

    .box-t1 h6  {
      text-align: center;
      font-weight: 600;
      margin-top: 8px;
      color: #007976;
      font-size: 1.1rem;
    }

    .box-t1 img  {
      display: flex;
      margin: 0 auto;
    }
    .main-content {
      flex: 1;
    }
    .two-column-layout {
      display: flex;
      gap: 2rem;
    }
    /* section cards */
    .section-card ul li  {
      list-style-type: disc;
      color: #1f2e45;
    }
    .section-card h5  {
      color: #1a1a1a;
      font-weight: 500;
      border-bottom: 1px solid #32D674;
      padding-bottom: 0.5rem;
      display: inline-block;
    }
    .section-card:first-child {
      padding-top:0;
    }
    .section-card {
      background: white;
      border-radius: 2rem;
      margin-bottom: 0;
      padding: 1.8rem 2rem;
      transition: all 0.2s;
      scroll-margin-top: 30px;
    }
    .section-card:last-child {
      margin-bottom: 0;
    }
    .section-card h2 {
      font-size: 1.3rem;
      font-weight: 700;
      letter-spacing: 0px;
      background: linear-gradient(white, white) padding-box,
                  linear-gradient(45deg, #68c18d, #4f7cbe) border-box;
      border: 3px solid transparent;
      color: #4f7cbe;
      margin-bottom: 1rem;
      padding: 1.5rem;
      border-radius: 1.2rem;
      position: relative;
    }
    .heading-icon  {position: absolute; right:0; top:-2px;height: 71px;}
    .section-card p {
      line-height: 1.6;
      margin-bottom: 1rem;
      color: #1f2e45;
    }
    .code-snip {
      background: #eef3fc;
      padding: 0.7rem 1rem;
      border-radius: 1rem;
      font-family: 'SF Mono', 'Fira Code', monospace;
      font-size: 0.85rem;
      color: #155799;
      margin: 1rem 0;
      border-left: 3px solid #2c6e9e;
    }
    .badge {
      display: inline-block;
      background: #e1efff;
      color: #1e5a9c;
      font-size: 0.7rem;
      font-weight: 600;
      padding: 0.2rem 0.8rem;
      border-radius: 30px;
      margin-bottom: 1rem;
    }
    .feature-grid {
      display: flex;
      flex-wrap: wrap;
      gap: 1rem;
      margin: 1.5rem 0 0.5rem;
    }
    .feature-item {
      background: #f8fafd;
      border-radius: 1.2rem;
      padding: 0.8rem 1.2rem;
      flex: 1 1 130px;
      border: 1px solid #dee9f2;
      font-weight: 500;
      font-size: 0.85rem;
    }
    hr {
      margin: 1rem 0;
      border: none;
      height: 1px;
      background: #888;
    }
    footer {
      margin-top: 3rem;
      text-align: center;
      font-size: 0.75rem;
      color: #5e7a9a;
      padding-top: 1rem;
      border-top: 1px solid #dce5ef;
    }

    /* ----- responsive breakpoints ----- */
    @media (max-width: 780px) {
      .app-wrapper {
        padding: 0;
      }
      .two-column-layout {
        flex-direction: column;
      }
      /* hide desktop sidebar, show mobile select */
      .desktop-nav {
        display: none;
      }
      .mobile-select-container {
        display: block;
      }
      .section-card {
        padding: 1.3rem 1.4rem;
      }
      .section-card h2 {
        font-size: 1.5rem;
      }
    }


    /* small additional touch */
    @media (max-width: 480px) {
      .section-card {
        scroll-margin-top: 70px;
      }
      .feature-item {
        flex: 1 1 100%;
      }
    }