discourse/app/assets/stylesheets/common/components/bookmark-modal.scss

.bookmark-with-reminder.modal {
  .modal-body {
    max-width: 410px;
    min-width: 380px;

    .control-label {
      font-weight: 700;
    }

    .ember-text-field.bookmark-name {
      width: 100%;
    }
  }
}