how to write css in different browser..Prevent Bootstrap Modal from disappearing when clicking outside or pressing escape?

1.Prevent Bootstrap Modal from disappearing when clicking outside or pressing escape?

If using javascript then:

$('#myModal').modal({
    backdrop: 'static',
    keyboard: false
})
and if HTML:
<a data-controls-modal="your_div_id" data-backdrop="static" data-keyboard="false" href="#">

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2.how to find ip address in php
<?php echo $_SERVER["REMOTE_ADDR"];     ?>
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3.how to get base url
<?php echo getcwd(); ?>
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4. how to write css in different browser..
.safari { /* Safari only */ }
.mac { /* Mac only */ }
.safari.mac { /* Safari Mac */ }
html:not(.safari) { /* All browsers except for Safari */ }
html:not(.safari.mac) { /* All browsers except for Safari Mac */ }
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