:root {
      /* Brand - Deep Trustworthy Blue */
      --brand-600: #0284c7;
      /* Sky-600 */
      --brand-700: #0369a1;
      /* Sky-700 */
      --accent-500: #38bdf8;
      /* Sky-400 */
      --accent-600: #0284c7;

      /* Light Surface */
      --bg-950: #f8fafc;
      /* Page BG (Slate-50) */
      --bg-900: #ffffff;
      /* Section BG */
      --bg-850: #f1f5f9;
      /* Panels blend */
      --panel: #ffffff;
      /* Cards (White) */
      --panel-2: #f8fafc;
      /* Subtle gradient stop */

      /* Text */
      --ink: #0f172a;
      /* Slate-900 */
      --muted: #475569;
      /* Slate-600 */
      --hint: #94a3b8;
      /* Slate-400 */

      /* Lines & Effects */
      --line: #e2e8f0;
      /* Slate-200 */
      --chip: #e0e7ff;
      /* Light Indigo tint */
      --radius: 12px;
      /* Standardized Radius */
      --radius-sm: 8px;
      --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.1);
      --shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
      --container: 1600px;
    }

    /* Base typography */
    body {
      font-size: 16px;
      /* Slightly reduced base size for denser info density */
    }

    @media (min-width:1024px) {
      body {
        font-size: 16px;
      }
    }

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


    html {
      scroll-behavior: smooth
    }

    body {
      font-family: "Inter", sans-serif;
      background: var(--bg-950);
      color: var(--ink);
      line-height: 1.7;
      -webkit-font-smoothing: antialiased;
      text-rendering: optimizeLegibility;
    }

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

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

    :focus-visible {
      outline: 3px solid var(--accent-600);
      outline-offset: 2px;
      border-radius: 8px
    }

    .container {
      max-width: 1180px;
      margin: 0 auto;
      padding: 0 1rem
    }

    .section {
      padding: 4.8rem 0
    }

    .section-title {
      font-size: clamp(1.9rem, 3.5vw, 2.3rem);
      text-align: center;
      margin-bottom: 2rem;
      color: var(--ink);
    }

    /* BUTTONS (global, large by default) */
    /* BUTTONS (global, large by default) */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: .7rem;
      padding: 1rem 1.8rem;
      border-radius: var(--radius-sm);
      font-weight: 700;
      font-size: 1.05rem;
      letter-spacing: .2px;
      line-height: 1.2;
      min-height: 52px;
      transition: all .2s ease;
      will-change: transform;
      border: 1px solid transparent;
      cursor: pointer;
    }

    .btn-primary {
      background: var(--brand-600);
      color: #ffffff;
      border: 1px solid var(--brand-700);
      box-shadow: 0 4px 6px -1px rgba(2, 132, 199, 0.3);
    }

    .btn-primary:hover {
      background: var(--brand-700);
      transform: translateY(-1px);
    }

    .btn-secondary {
      background: #ffffff;
      color: var(--ink);
      border: 1px solid var(--line);
      box-shadow: var(--shadow-sm);
    }

    .btn-secondary:hover {
      border-color: var(--brand-600);
      color: var(--brand-600);
    }

    .btn-info {
      background: var(--accent-500);
      color: #ffffff;
      border: 1px solid var(--accent-600);
    }

    .btn-ghost {
      background: transparent;
      color: var(--muted);
      border: 2px solid transparent;
    }

    .btn:hover {
      transform: translateY(-1px);
      box-shadow: var(--shadow)
    }

    .btn-ghost:hover {
      background: var(--bg-850);
      color: var(--brand-600)
    }

    /* XL action utility for critical CTAs */
    .btn-action {
      font-size: 1.22rem;
      padding: 1.2rem 2rem;
      min-height: 58px;
      letter-spacing: .28px;
    }

    @media (max-width:640px) {
      .btn {
        font-size: 1.08rem;
        padding: 1rem 1.3rem;
        min-height: 50px;
      }

      .btn-action {
        font-size: 1.14rem;
        padding: 1.05rem 1.5rem;
        min-height: 52px;
      }
    }

    /* HEADER */
    /* HEADER */
    header {
      position: sticky;
      top: 0;
      z-index: 40;
      background: rgba(255, 255, 255, 0.9);
      border-bottom: 1px solid var(--line);
      backdrop-filter: saturate(180%) blur(12px);
    }

    nav {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 1rem;
      padding: .9rem 0
    }

    .logo {
      color: var(--brand-700);
      font-size: 1.3rem;
      font-weight: 800;
      letter-spacing: -0.5px
    }

    .nav-links {
      display: flex;
      align-items: center;
      flex-wrap: wrap;
      gap: 1.5rem
    }

    .nav-links .btn-outline {
      margin-right: 0;
      color: var(--muted);
      font-weight: 600;
      padding: 0.5rem 0.8rem;
    }

    .nav-links .btn-outline:hover {
      color: var(--brand-600);
      background: transparent;
    }

    .login {
      background: var(--bg-850);
      border: 1px solid var(--line);
      color: var(--ink);
      padding: .55rem 1.25rem;
      font-weight: 700;
      border-radius: var(--radius-sm)
    }

    .login:hover {
      background: var(--white);
      border-color: var(--brand-600);
      color: var(--brand-600)
    }

    /* HERO */
    /* HERO */
    .hero {
      background: radial-gradient(circle at 50% 10%, #f0f9ff, #f8fafc);
      color: var(--ink);
      text-align: center;
      position: relative;
      overflow: hidden;
      border-bottom: 1px solid var(--line);
    }

    .hero-inner {
      padding: 6rem 1rem 6.2rem
    }

    .hero h1 {
      font-size: clamp(2.6rem, 5.2vw, 3.6rem);
      font-weight: 800;
      line-height: 1.12;
      margin-bottom: 1.05rem;
      color: var(--ink)
    }

    .hero p {
      font-size: 1.15rem;
      max-width: 800px;
      margin: 0 auto 2rem;
      color: var(--muted);
      font-weight: 400;
    }

    .hero-ctas {
      display: flex;
      align-items: center;
      justify-content: center;
      flex-wrap: wrap;
      gap: 1rem 1.4rem
    }

    .hero-ctas .btn {
      margin: 0
    }

    .hero-sub {
      margin-top: 1.5rem;
      font-size: .9rem;
      color: var(--hint);
      font-weight: 500;
    }

    /* AUDIENCE */
    .audience {
      background: var(--bg-900)
    }

    .audience p {
      color: var(--muted);
      max-width: 820px;
      margin: 0 auto 1.3rem;
      text-align: center
    }

    .checklist {
      display: grid;
      gap: 1.5rem;
      grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
      list-style: none;
      max-width: 980px;
      margin: 2rem auto 0;
      align-items: stretch;
    }

    .checklist li {
      background: var(--panel);
      border: 1px solid var(--line);
      padding: 1.5rem;
      border-radius: var(--radius);
      display: flex;
      align-items: center;
      gap: .75rem;
      color: var(--ink);
      box-shadow: var(--shadow-sm);
      height: 100%;
    }

    /* GRID + CARDS */
    /* GRID + CARDS */
    .grid {
      display: grid;
      gap: 1.5rem;
      grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
      align-items: stretch;
    }

    .card {
      position: relative;
      background: var(--panel);
      border: 1px solid var(--line);
      border-radius: var(--radius);
      box-shadow: var(--shadow-sm);
      padding: 2rem 1.5rem;
      text-align: left;
      display: flex;
      flex-direction: column;
      gap: 1rem;
      transition: transform .25s ease, box-shadow .25s ease;
      height: 100%;
      /* Force equal height */
    }

    .app-card {
      overflow: hidden
    }

    .app-card:before {
      content: "";
      position: absolute;
      inset: 0 0 auto 0;
      height: 4px;
      background: var(--brand-600);
    }

    .card h3 {
      color: var(--ink);
      font-size: 1.2rem;
      font-weight: 700;
    }

    .card p {
      color: var(--muted);
      font-size: 1rem;
      flex: 1;
      line-height: 1.6;
    }

    .card .note {
      font-size: 0.9rem
    }

    /* PRICING */
    .pricing {
      background: var(--bg-850)
    }

    .price-card {
      background: var(--panel);
      border: 1px solid var(--line);
      border-radius: var(--radius);
      box-shadow: var(--shadow-sm);
      padding: 2.5rem 2rem;
      text-align: center;
      display: flex;
      flex-direction: column;
      gap: 1rem;
      transition: .25s;
      height: 100%;
    }

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

    .price-card.featured {
      border: 2px solid var(--brand-600);
      transform: scale(1.02);
    }

    .price-card h3 {
      font-size: 1.25rem;
      color: var(--ink);
      font-weight: 700
    }

    .price {
      font-size: 2.5rem;
      font-weight: 800;
      color: var(--brand-600)
    }

    .cases-tag {
      font-size: .9rem;
      color: var(--muted)
    }

    /* FAQ */
    .faq-item+.faq-item {
      margin-top: 1.4rem
    }

    .faq-item h4 {
      font-size: 1.05rem;
      color: var(--ink);
      margin-bottom: .35rem;
      font-weight: 700
    }

    .faq-item p {
      font-size: 1.02rem;
      color: var(--muted);
      line-height: 1.6;
    }

    /* FOOTER */
    footer {
      background: var(--bg-950);
      color: var(--muted);
      border-top: 1px solid var(--line);
    }

    .footer-flex {
      display: grid;
      grid-template-columns: 1fr;
      gap: 2.2rem;
      padding: 3rem 0
    }

    .footer-links h4 {
      color: var(--ink);
      margin-bottom: .6rem;
      font-weight: 700;
    }

    .footer-links a {
      color: var(--muted);
      font-size: .92rem;
      display: block;
      margin-top: .45rem
    }

    .footer-links a:hover {
      color: var(--brand-600)
    }

    .copy {
      text-align: center;
      font-size: .85rem;
      color: var(--hint);
      padding-bottom: 1.6rem
    }

    @media(min-width:768px) {
      .footer-flex {
        grid-template-columns: 1.2fr .8fr .8fr;
        align-items: start
      }
    }

    /* MOBILE TWEAKS */
    @media (max-width:520px) {
      .nav-links {
        gap: .6rem
      }
    }

    /* Specific App Styles */
    .navbar {
      position: sticky;
      top: 0;
      z-index: 50;
      background: #ffffff;
      border-bottom: 1px solid var(--line);
      box-shadow: var(--shadow-sm);
      backdrop-filter: saturate(180%) blur(12px);
    }

    .navbar-inner {
      max-width: var(--container);
      margin: 0 auto;
      padding: .9rem 1rem;
      display: flex;
      justify-content: space-between;
      align-items: center;
      gap: 1rem;
    }

    .navbar-brand {
      font-size: 1.3rem;
      font-weight: 800;
      color: var(--brand-700);
      letter-spacing: -0.5px;
      margin-right: 1.5rem;
    }

    .navbar-right {
      display: flex;
      align-items: center;
      gap: 1rem;
    }

    /* User info text in navbar */
    .user-info-group {
      display: flex;
      flex-direction: column;
      align-items: flex-end;
      line-height: 1.2;
      margin-right: 0.5rem;
      text-align: right;
    }

    .user-email {
      font-size: 0.85rem;
      font-weight: 600;
      color: var(--ink);
    }

    .user-credits {
      font-size: 0.8rem;
      color: var(--muted);
    }

    .user-credits strong {
      color: var(--brand-700);
    }

    .instructions-box {
      font-size: 1rem;
      font-weight: 700;
      color: var(--muted);
      border: none;
      background: transparent;
      padding: .25rem;
      text-decoration: none;
      border-bottom: 2px solid transparent;
    }

    .instructions-box:hover {
      color: var(--ink);
      border-bottom-color: var(--brand-600);
    }

    /* Buttons (ensure they match global) */
    /* .btn { inherited from global } */

    .navbar-text {
      font-size: 1rem;
      color: var(--muted);
    }

    /* Page Container */
    .wrap {
      max-width: var(--container);
      width: 96%;
      margin: 1rem auto 2rem;
      padding: 0 0.5rem;
      flex: 1;
    }

    /* Card */
    .card {
      position: relative;
      background: linear-gradient(180deg, var(--panel), var(--panel-2));
      border: 1.5px solid rgba(148, 163, 184, .35);
      border-radius: var(--radius);
      box-shadow: 0 20px 60px rgba(0, 0, 0, .45);
    }

    .card-header {
      padding: 1.5rem 1.6rem;
      border-bottom: 1px solid var(--line);
      display: flex;
      justify-content: space-between;
      align-items: center;
      gap: 1rem;
    }

    .card-title {
      font-size: 1.6rem;
      font-weight: 800;
      color: var(--ink);
      letter-spacing: -0.5px;
    }

    .card-subtitle {
      font-size: 1.05rem;
      color: var(--muted);
      margin-top: 4px;
      max-width: 980px;
    }

    .card-body {
      padding: 1.85rem;
    }

    /* Forms */
    .form-group label {
      color: var(--ink);
      font-weight: 700;
      font-size: 1rem;
      margin-bottom: .45rem;
      display: inline-block;
    }

    .form-control,
    .form-control-file {
      background: var(--bg-950);
      border: 1px solid var(--line);
      color: var(--ink);
      padding: 0.9rem 1rem;
      border-radius: var(--radius-sm);
      font-size: 1rem;
      line-height: 1.5;
      caret-color: var(--brand-600);
      transition: all 0.2s;
    }

    .form-control:focus,
    .form-control-file:focus {
      outline: none;
      border-color: var(--brand-600);
      box-shadow: 0 0 0 3px rgba(2, 132, 199, 0.15);
      background: #ffffff;
    }

    .form-control-file {
      border-style: dashed;
      border-width: 2px;
    }

    .form-control-file:hover {
      background: #ffffff;
      border-color: var(--brand-500);
    }

    .form-group+.form-group {
      margin-top: 1.5rem;
    }

    input::placeholder {
      color: var(--hint);
      opacity: 1
    }

    .section-h {
      font-size: 1.15rem;
      font-weight: 800;
      color: var(--ink);
      margin: 1.4rem 0 .6rem;
    }

    .step-list {
      counter-reset: step;
      list-style: none;
      margin: .2rem 0 1.2rem;
      padding: 0;
    }

    .step-list li {
      counter-increment: step;
      position: relative;
      padding-left: 2.2rem;
      margin: .55rem 0;
      color: var(--muted);
    }

    .step-list li::before {
      content: counter(step)".";
      position: absolute;
      left: 0;
      top: 0;
      width: 1.6rem;
      text-align: right;
      font-weight: 800;
      color: var(--brand-600);
    }

    /* Helper Blocks */
    .help-text {
      background: #f0f9ff;
      border-left: 4px solid var(--brand-600);
      padding: 1rem;
      font-size: 0.95rem;
      border-radius: var(--radius-sm);
      margin: .8rem 0;
      color: var(--ink);
      font-weight: 500;
    }

    /* Emphasis for Colonoscopy PDF help */
    label[for="pdfFiles"]+.help-text {
      font-size: 1rem;
      line-height: 1.6;
      color: var(--ink);
      background: #eff6ff;
      border-left-width: 4px;
      padding: 1rem;
    }

    .note {
      font-size: 0.9rem;
      color: var(--muted);
    }

    /* Alerts */
    .alert {
      max-width: 860px;
      margin: 1rem 0;
      padding: 1rem 1.25rem;
      border-radius: var(--radius);
      border: 1px solid transparent;
      font-weight: 600;
    }

    .alert-danger {
      background: #fef2f2;
      border-color: #fee2e2;
      color: #991b1b;
    }

    .alert-success {
      background: #f0fdf4;
      border-color: #dcfce7;
      color: #166534;
    }

    .alert-info {
      background: #eff6ff;
      border-color: #dbeafe;
      color: #1e40af;
    }

    /* Progress & Spinner */
    .progress-wrap {
      margin-top: 1.5rem;
      display: none;
    }

    .progress {
      width: 100%;
      height: 12px;
      background: var(--line);
      border-radius: 999px;
      overflow: hidden;
    }

    .progress-fill {
      height: 100%;
      width: 0%;
      background: var(--brand-600);
      color: #ffffff;
      font-weight: 700;
      text-align: center;
      font-size: .75rem;
      line-height: 12px;
    }

    .progress-status {
      margin-top: .6rem;
      font-size: .95rem;
      color: var(--muted);
      font-weight: 600;
    }

    .spinner {
      display: inline-block;
      width: 18px;
      height: 18px;
      border: 2px solid rgba(255, 255, 255, 0.3);
      border-radius: 50%;
      border-top-color: #fff;
      animation: spin 0.8s linear infinite;
      vertical-align: middle;
    }

    @keyframes spin {
      to {
        transform: rotate(360deg);
      }
    }

    /* Footer */
    .mini-footer {
      max-width: var(--container);
      margin: 0 auto 2rem;
      padding: 0 1rem;
      color: var(--muted);
      text-align: center;
      font-size: 1rem;
    }

    .mini-footer a {
      color: var(--brand-600);
      text-decoration: underline;
    }

    .mini-footer a:hover {
      color: var(--brand-700);
    }

    @media (max-width: 640px) {
      .navbar-inner {
        flex-direction: column;
        gap: .75rem;
      }

      .card-header {
        flex-direction: column;
        align-items: flex-start;
      }
    }