:root {
      --bg-card: #ffffff;

      --accent: #111827;
      --accent-soft: #e5e7eb;
      --accent-strong: #111827;

      --text-main: #111827;
      --text-muted: #6b7280;

      --radius-xl: 18px;
    }

    /* ✅ SOLO CAMBIO AQUÍ: exterior blanco, limpio, con toque sutil */

    .signup-shell {
      width: 100%;
      max-width: 500px;
      position: relative;
      margin-left: auto;
      margin-right: auto;
      margin-bottom: 16px;
    }

    .signup-shell::before{
      content:"";
      position:absolute;
      inset:-40px;
      pointer-events:none;
      background:
        radial-gradient(520px 340px at 24% 12%, rgba(255, 255, 255, 0.72), transparent 78%),
        radial-gradient(480px 320px at 78% 10%, rgba(248, 251, 255, 0.36), transparent 76%),
        radial-gradient(580px 360px at 52% 28%, rgba(241, 246, 254, 0.26), transparent 82%);
      filter: blur(26px);
      z-index: 0;
    }

    .signup-card {
      position: relative;
      z-index: 1;
      background: var(--bg-panel);
      border-radius: 24px;
      padding: 22px 20px 18px;
      box-shadow: var(--shadow-soft);
      border: 1px solid rgba(148, 163, 184, 0.18);
    }

    .signup-header {
      text-align: center;
      margin-bottom: 14px;
    }

    .brand-row {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 12px;
      flex-wrap: wrap;
    }

    /* Badge actualizado para Neurasoundlab.ai (mantiene el toque claro, con glow suave) */

    .brand-title {
      margin: 0;
      font-size: 1.18rem;
      font-weight: 600;
      letter-spacing: 0.2px;
      line-height: 1.15;
    }

    .brand-initial {
      font-size: 1.4em;
      font-weight: 800;
      letter-spacing: 0.4px;
      display: inline-block;
      line-height: 0.9;
      color: #7a5cff;
    }

    .brand-accent {
      background: linear-gradient(90deg, #6fa4ff, #8cb4ff);
      -webkit-background-clip: text;
      background-clip: text;
      color: transparent;
    }

    .signup-header small {
      display: block;
      margin-top: 6px;
      color: var(--text-muted);
      font-size: 0.82rem;
    }

    .signup-title {
      margin-top: 6px;
      font-size: 1.08rem;
      font-weight: 700;
      color: #0f1d57;
      letter-spacing: .15px;
      line-height: 1.15;
      text-wrap: balance;
    }

    .signup-header small{
      margin-top: 5px;
      color: #6f7890;
      font-size: .79rem;
      letter-spacing: .05px;
    }

    .signup-card .row {
      --bs-gutter-x: .65rem;
    }

    .signup-card .mb-3{
      margin-bottom: .65rem !important;
    }

    .signup-flash-stack{
      display: grid;
      gap: 8px;
      margin: 0 0 12px;
    }

    .signup-flash-item{
      display: flex;
      align-items: flex-start;
      gap: 8px;
      border-radius: 12px;
      padding: 9px 11px;
      font-size: 0.84rem;
      line-height: 1.35;
      border: 1px solid;
    }

    .signup-flash-item i{
      margin-top: 1px;
      flex: 0 0 auto;
    }

    .signup-flash-item span{
      overflow-wrap: anywhere;
      word-break: break-word;
    }

    .signup-flash-item-success{
      background: #edf9f2;
      border-color: #b8e7ca;
      color: #11643a;
    }

    .signup-flash-item-success i{
      color: #12824b;
    }

    .signup-flash-item-error{
      background: #fff1f3;
      border-color: #f4c8d0;
      color: #8f1f34;
    }

    .signup-flash-item-error i{
      color: #b4233a;
    }

    .form-control,
    .form-select {
      border-radius: 999px;
      border: 1px solid var(--border-soft);
      font-size: 0.9rem;
      padding: 8px 14px;
      background-color: #ffffff;
      transition: border-color 0.2s ease, box-shadow 0.2s ease;
    }

    .form-control:focus,
    .form-select:focus {
      border-color: var(--blue);
      box-shadow: 0 0 0 2px rgba(90, 124, 255, 0.16);
    }

    /* Estilos para campos inválidos */
    .form-control.is-invalid,
    .form-select.is-invalid {
      border-color: #dc3545;
      background-color: #fff5f5;
    }

    .form-control.is-invalid:focus,
    .form-select.is-invalid:focus {
      border-color: #dc3545;
      box-shadow: 0 0 0 2px rgba(220, 53, 69, 0.15);
    }

    .form-check-input.is-invalid {
      border-color: #dc3545;
    }

    .invalid-feedback {
      display: none;
      font-size: 0.75rem;
      color: #dc3545;
      margin-top: 3px;
      margin-left: 14px;
    }

    .is-invalid ~ .invalid-feedback,
    .form-check-input.is-invalid ~ .invalid-feedback {
      display: block;
    }

    /* Icono de error/éxito en inputs */
    .form-control.is-invalid {
      background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 12 12' width='12' height='12' fill='none' stroke='%23dc3545'%3e%3ccircle cx='6' cy='6' r='4.5'/%3e%3cpath stroke-linejoin='round' d='M5.8 3.6h.4L6 6.5z'/%3e%3ccircle cx='6' cy='8.2' r='.6' fill='%23dc3545' stroke='none'/%3e%3c/svg%3e");
      background-repeat: no-repeat;
      background-position: right 14px center;
      background-size: 14px 14px;
      padding-right: 36px;
    }

    .form-control.is-valid {
      border-color: #28a745;
      background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 8 8'%3e%3cpath fill='%2328a745' d='M2.3 6.73L.6 4.53c-.4-1.04.46-1.4 1.1-.8l1.1 1.4 3.4-3.8c.6-.63 1.6-.27 1.2.7l-4 4.6c-.43.5-.8.4-1.1.1z'/%3e%3c/svg%3e");
      background-repeat: no-repeat;
      background-position: right 14px center;
      background-size: 14px 14px;
      padding-right: 36px;
    }

    /* Requisitos de contraseña */
    .password-requirements {
      font-size: 0.75rem;
      margin-top: 4px;
      margin-left: 14px;
      min-height: 0;
    }

    .password-requirements div {
      color: #6b7280;
      margin: 2px 0;
      display: flex;
      align-items: center;
      gap: 6px;
    }

    .password-requirements div.valid {
      color: #28a745;
    }

    .password-requirements div.invalid {
      color: #dc3545;
    }

    .password-requirements i {
      font-size: 0.7rem;
    }

    /* Botón principal con toque Neurasoundlab.ai */

    .btn-ghost {
      border-radius: 999px;
      border: 1px solid var(--border-soft);
      background: #ffffff;
      font-size: 0.82rem;
      padding: 7px 14px;
      width: 100%;
      color: var(--text-muted);
      display: inline-flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
    }

    .btn-ghost:hover {
      border-color: #111827;
      color: #111827;
    }

    .signup-actions {
      display: block;
      width: 100%;
      margin-bottom: 2px;
    }

    .signup-actions .btn-primary-main,
    .signup-actions .btn-ghost {
      width: 100%;
      margin-bottom: 0 !important;
      padding: 8px 10px;
      font-size: 0.8rem;
      gap: 6px;
      white-space: nowrap;
    }

    .divider {
      display: flex;
      align-items: center;
      text-align: center;
      margin: 10px 0 12px;
    }

    .divider::before,
    .divider::after {
      content: "";
      flex: 1;
      border-bottom: 1px solid var(--border-soft);
    }

    .divider span {
      font-size: 0.78rem;
      color: var(--text-muted);
      margin: 0 10px;
    }

    .gender-group-label {
      font-size: 0.8rem;
      font-weight: 500;
      color: var(--text-main);
      margin-bottom: 4px;
    }

    .signup-demographics-row .gender-field-col {
      display: flex;
      flex-direction: column;
      justify-content: flex-end;
    }

    .signup-demographics-row .gender-group-label {
      margin-bottom: 6px;
      min-height: 19px;
    }

    .signup-demographics-row .gender-options-row {
      min-height: 38px;
      align-items: flex-end !important;
      padding-bottom: 2px;
    }

    .signup-demographics-row .gender-options-row .form-check {
      margin-bottom: 0;
    }

    .form-check-inline {
      margin-right: 16px;
    }

    .form-check-label {
      font-size: 0.8rem;
      color: var(--text-muted);
    }

    .terms-text {
      font-size: 0.78rem;
      color: var(--text-muted);
    }

    .terms-text a {
      color: var(--accent);
      text-decoration: none;
      font-weight: 600;
    }

    .terms-text a:hover {
      text-decoration: underline;
    }

    @media (min-width: 992px){
      .signup-shell{
        max-width: 480px;
      }
    }

    .terms-modal .modal-content{
      border-radius: 18px;
      border: 1px solid rgba(148, 163, 184, 0.2);
      box-shadow: 0 20px 50px rgba(15, 23, 42, 0.18);
      background: #ffffff;
    }

    .terms-modal .modal-header{
      border-bottom: 1px solid rgba(148, 163, 184, 0.2);
    }

    .terms-modal .modal-title{
      font-weight: 700;
      color: var(--text-main);
    }

    .terms-modal .terms-scroll{
      max-height: 60vh;
      overflow: auto;
      padding-right: 6px;
      color: var(--text-main);
      font-size: 0.92rem;
    }

    .terms-modal .terms-scroll h6{
      font-weight: 700;
      margin-top: 14px;
    }

    .terms-modal .terms-scroll p{
      color: var(--text-muted);
      margin-bottom: 10px;
    }

    .terms-modal .modal-footer{
      border-top: 1px solid rgba(148, 163, 184, 0.2);
    }

    .signup-footer-text {
      font-size: .82rem;
      color: var(--text-muted);
      text-align: center;
      margin-top: 12px;
      font-family: "Inter", system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
    }

    .signup-footer-text a{
      color: #111827;
      text-decoration: none;
      font-weight: 600;
    }

    .signup-footer-text a:hover{
      text-decoration: underline;
    }

    @media (max-width: 576px) {
      .auth-page-content{
        align-items: flex-start;
      }

      .signup-shell {
        max-width: 430px;
        margin-top: 0;
        margin-bottom: 12px;
      }

      .signup-card {
        border-radius: 22px;
        padding: 20px 15px 16px;
        box-shadow: 0 12px 24px rgba(15, 23, 42, 0.10);
      }

      .signup-card .row {
        --bs-gutter-x: .52rem;
      }

      .signup-card .mb-3{
        margin-bottom: .58rem !important;
      }

      .signup-flash-stack{
        margin-bottom: 10px;
      }

      .signup-flash-item{
        font-size: 0.8rem;
        border-radius: 10px;
        padding: 8px 10px;
      }

      .signup-actions {
        grid-template-columns: 1fr;
        gap: 7px;
      }

      .signup-actions .btn-primary-main,
      .signup-actions .btn-ghost {
        min-height: 44px;
        font-size: 0.84rem;
        white-space: normal;
      }

      .invalid-feedback{
        margin-left: 10px;
      }

      .form-check-inline {
        margin-right: 8px;
        margin-bottom: 4px;
      }

      .form-check-label{
        font-size: 0.82rem;
      }

      .signup-demographics-row .gender-group-label{
        margin-bottom: 5px;
        min-height: 0;
      }

      .signup-demographics-row .gender-options-row{
        min-height: 0;
        padding-bottom: 0;
      }

      .brand-row {
        flex-direction: column;
        gap: 8px;
      }

      .brand-title {
        font-size: 1.05rem;
      }

      .signup-title {
        font-size: 0.98rem;
      }

      .terms-text{
        font-size: 0.76rem;
        line-height: 1.36;
      }

      .signup-footer-text{
        margin-top: 10px;
        font-size: 0.8rem;
      }
    }

    @media (max-width: 390px){
      .signup-card{
        padding: 18px 12px 14px;
      }
    }