wea para cargar por include diferentes vistas de un archivo, para diseños con UI diferentes en movil-tablet-pc y no quieras complicarte la vida con poner todo en un solo html-css gigante

load.php

<?php

function load_view($movil, $tablet,$pc_master_race){
    $tablet_browser = 0; $mobile_browser = 0; $body_class = 'desktop';
 
    if (preg_match('/(tablet|ipad|playbook)|(android(?!.*(mobi|opera mini)))/i', strtolower($_SERVER['HTTP_USER_AGENT']))) { $tablet_browser++; }
 
    if (preg_match('/(up.browser|up.link|mmp|symbian|smartphone|midp|wap|phone|android|iemobile)/i', strtolower($_SERVER['HTTP_USER_AGENT']))) { $mobile_browser++; }
 
    if ((strpos(strtolower($_SERVER['HTTP_ACCEPT']),'application/vnd.wap.xhtml+xml') > 0) or ((isset($_SERVER['HTTP_X_WAP_PROFILE']) or isset($_SERVER['HTTP_PROFILE'])))) { $mobile_browser++; }
 
    $mobile_ua = strtolower(substr($_SERVER['HTTP_USER_AGENT'], 0, 4));
    $mobile_agents = array(
        'w3c ','acs-','alav','alca','amoi','audi','avan','benq','bird','blac',
        'blaz','brew','cell','cldc','cmd-','dang','doco','eric','hipt','inno',
        'ipaq','java','jigs','kddi','keji','leno','lg-c','lg-d','lg-g','lge-',
        'maui','maxo','midp','mits','mmef','mobi','mot-','moto','mwbp','nec-',
        'newt','noki','palm','pana','pant','phil','play','port','prox',
        'qwap','sage','sams','sany','sch-','sec-','send','seri','sgh-','shar',
        'sie-','siem','smal','smar','sony','sph-','symb','t-mo','teli','tim-',
        'tosh','tsm-','upg1','upsi','vk-v','voda','wap-','wapa','wapi','wapp',
        'wapr','webc','winw','winw','xda ','xda-');
 
    if (in_array($mobile_ua,$mobile_agents)) { $mobile_browser++; }
 
    if (strpos(strtolower($_SERVER['HTTP_USER_AGENT']),'opera mini') > 0) {
        $mobile_browser++;
        $stock_ua = strtolower(isset($_SERVER['HTTP_X_OPERAMINI_PHONE_UA'])?$_SERVER['HTTP_X_OPERAMINI_PHONE_UA']:(isset($_SERVER['HTTP_DEVICE_STOCK_UA'])?$_SERVER['HTTP_DEVICE_STOCK_UA']:''));
        if (preg_match('/(tablet|ipad|playbook)|(android(?!.*mobile))/i', $stock_ua)) { $tablet_browser++; }
    }
    if ($tablet_browser > 0) {  include_once($tablet); }
    else if ($mobile_browser > 0) { include_once($movil); }
    else { include($pc_master_race); } 
} 
?>