The actual look of CF7 forms on your website will depend largely on the current WordPress theme used and the CSS styling that theme applies to standard HTML form elements. To change the style of your CF7 forms you would need to edit the CSS style sheets used by your WordPress theme.
See Styling Contact Form 7 Forms for a general explanation of styling CF7 forms using CSS.
The problem is cause by the code below
#bbpress-forums .bbp-search-form #bbp_search, #comment-input input, #tribe-bar-form input[type="text"], .avada-select .select2-container .select2-choice, .avada-select-parent select, .avada-shipping-calculator-form .avada-select-parent select, .bbp-login-form input, .bbp-reply-form input#bbp_topic_tags, .bbp-topic-form input#bbp_topic_tags, .bbp-topic-form input#bbp_topic_title, .bbp-topic-form select#bbp_stick_topic_select, .bbp-topic-form select#bbp_topic_status_select, .cart-collaterals .avada-select-parent input, .cart-collaterals .form-row input, .cart-collaterals .shipping_calculator #calc_shipping_postcode, .checkout .input-text:not(textarea), .chzn-container .chzn-drop, .chzn-container-single .chzn-single, .coupon .input-text, .input-text:not(textarea), .main-nav-search-form input, .post-password-form .password, .search-page-search-form input, .searchform .search-table .search-field input, .shipping-calculator-form .avada-select-parent select, .woocommerce-checkout .select2-drop-active, .wpcf7-captchar, .wpcf7-form .wpcf7-date, .wpcf7-form .wpcf7-number, .wpcf7-form .wpcf7-quiz, .wpcf7-form .wpcf7-select, .wpcf7-form .wpcf7-text, input.s, input[type="text"], select {
height: 0px; /* this is the problem */
padding-top: 0px;
padding-bottom: 0px;
}
