:root {
        --primary-color: #003366;
        --primary-strong: #022247;
        --accent-color: #f7f9fc;
        --ink-color: #1b2d43;
      }

      * {
        box-sizing: border-box;
      }

      body {
        min-height: 100vh;
        margin: 0;
        font-family: 'Manrope', 'Segoe UI', Roboto, sans-serif;
        background:
          radial-gradient(circle at 12% 8%, rgba(5, 82, 150, 0.25) 0%, rgba(5, 82, 150, 0) 36%),
          radial-gradient(circle at 94% 92%, rgba(200, 150, 36, 0.2) 0%, rgba(200, 150, 36, 0) 36%),
          linear-gradient(145deg, #e9f1fb 0%, #eef4fb 44%, #f8fafc 100%);
      }

      .auth-shell {
        min-height: 100vh;
        display: flex;
        align-items: center;
        justify-content: center;
        padding: 1.5rem;
        position: relative;
      }

      .auth-backdrop {
        position: absolute;
        inset: 0;
        pointer-events: none;
        background-image: linear-gradient(to right, rgba(0, 51, 102, 0.05) 1px, transparent 1px),
          linear-gradient(to bottom, rgba(0, 51, 102, 0.05) 1px, transparent 1px);
        background-size: 26px 26px;
        opacity: 0.35;
      }

      .login-card {
        width: 100%;
        max-width: 520px;
        border: 1px solid rgba(0, 51, 102, 0.12);
        border-radius: 1rem;
        box-shadow: 0 30px 70px rgba(19, 45, 76, 0.18);
        overflow: hidden;
        position: relative;
        z-index: 1;
        backdrop-filter: blur(6px);
      }

      .card-header {
        background: linear-gradient(120deg, var(--primary-color) 0%, var(--primary-strong) 100%);
        border-bottom: none;
        padding: 1.1rem 1.25rem;
      }

      .brand-logo {
        max-height: 64px;
        filter: drop-shadow(0 8px 20px rgba(0, 0, 0, 0.3));
      }

      .card-body {
        background: rgba(255, 255, 255, 0.94);
      }

      .form-label {
        color: var(--ink-color);
        letter-spacing: 0.01em;
      }

      .input-group-text {
        border-radius: 0.65rem 0 0 0.65rem;
      }

      .form-control {
        border-radius: 0 0.65rem 0.65rem 0;
        padding: 0.78rem 1rem;
        border: 1px solid #ced9e6;
      }

      .form-control:focus {
        border-color: var(--primary-color);
        box-shadow: 0 0 0 0.22rem rgba(0, 51, 102, 0.18);
      }

      .btn-ameripol {
        background: linear-gradient(135deg, var(--primary-color) 0%, #0b4d95 100%);
        color: white;
        padding: 0.86rem;
        font-weight: 700;
        border-radius: 0.7rem;
        border: 0;
        transition: transform 0.2s ease, box-shadow 0.2s ease;
      }

      .btn-ameripol:hover {
        color: white;
        transform: translateY(-1px);
        box-shadow: 0 12px 24px rgba(4, 52, 103, 0.3);
      }

      .card-footer {
        background-color: var(--accent-color);
        border-top: 1px solid #e4ebf3;
        padding: 1rem;
        text-align: center;
        font-size: 0.85rem;
      }

      @media (max-width: 575.98px) {
        .auth-shell {
          padding: 0;
          align-items: stretch;
        }

        .login-card {
          max-width: 100%;
          min-height: 100vh;
          border-radius: 0;
          box-shadow: none;
          border: 0;
        }

        .card-header {
          border-radius: 0;
          padding: 1rem;
        }

        .brand-logo {
          max-height: 56px;
        }
      }