| <!DOCTYPE html> | 
 | <title>CSS Anchor Positioning: try-tactic under different writing modes</title> | 
 | <link rel="help" href="https://drafts.csswg.org/css-anchor-position-1/#typedef-position-try-fallbacks-try-tactic"> | 
 | <script src="/resources/testharness.js"></script> | 
 | <script src="/resources/testharnessreport.js"></script> | 
 | <style> | 
 |   @position-try --pf { | 
 |     left:10px; | 
 |     top:20px; | 
 |   } | 
 |   #cb { | 
 |     position: absolute; | 
 |     width: 400px; | 
 |     height: 400px; | 
 |     border: 1px solid black; | 
 |   } | 
 |   #target { | 
 |     position: absolute; | 
 |     left: 99999px; /* force fallback */ | 
 |     width: 30px; | 
 |     height: 40px; | 
 |     background-color: skyblue; | 
 |   } | 
 | </style> | 
 | <div id=cb> | 
 |   <div id=target></div> | 
 | </div> | 
 | <script> | 
 |  | 
 |   function test_try_tactic_wm(try_tactic, writing_mode, direction, expected_offsets) { | 
 |     target.style.positionTryFallbacks = `--pf ${try_tactic}`; | 
 |     target.style.writingMode = writing_mode; | 
 |     target.style.direction = direction; | 
 |     test(() => { | 
 |       assert_equals(target.offsetLeft, expected_offsets.left, 'offsetLeft'); | 
 |       assert_equals(target.offsetTop, expected_offsets.top, 'offsetTop'); | 
 |       assert_equals(target.offsetWidth, expected_offsets.width, 'offsetWidth'); | 
 |       assert_equals(target.offsetHeight, expected_offsets.height, 'offsetHeight'); | 
 |     }, `${try_tactic} ${writing_mode} ${direction}`); | 
 |   } | 
 |  | 
 |   test_try_tactic_wm('', 'horizontal-tb', 'ltr', {left:10, top:20, width:30, height:40}); | 
 |  | 
 |   // Effectively flips left:10px to right:10px: | 
 |   test_try_tactic_wm('flip-inline', 'horizontal-tb', 'ltr', {left:360, top:20, width:30, height:40}); | 
 |   test_try_tactic_wm('flip-x', 'horizontal-tb', 'ltr', {left:360, top:20, width:30, height:40}); | 
 |  | 
 |   // Effectively flips top:20px to bottom:20px: | 
 |   test_try_tactic_wm('flip-inline', 'vertical-lr', 'ltr', {left:10, top:340, width:30, height:40}); | 
 |   test_try_tactic_wm('flip-inline', 'sideways-lr', 'ltr', {left:10, top:340, width:30, height:40}); | 
 |   test_try_tactic_wm('flip-y', 'vertical-lr', 'ltr', {left:10, top:340, width:30, height:40}); | 
 |   test_try_tactic_wm('flip-y', 'sideways-lr', 'ltr', {left:10, top:340, width:30, height:40}); | 
 |  | 
 |   // Effectively flips left:10px to right:10px: | 
 |   test_try_tactic_wm('flip-block', 'sideways-rl', 'ltr', {left:360, top:20, width:30, height:40}); | 
 |   test_try_tactic_wm('flip-x', 'sideways-rl', 'ltr', {left:360, top:20, width:30, height:40}); | 
 |  | 
 |   // Mirror across the [left,top]=>[bottom,right] diagonal: | 
 |   test_try_tactic_wm('flip-start', 'horizontal-tb', 'ltr', {left:20, top:10, width:40, height:30}); | 
 |  | 
 |   // Mirror across the [right,top]=>[bottom,left] diagonal: | 
 |   test_try_tactic_wm('flip-start', 'horizontal-tb', 'rtl', {left:340, top:360, width:40, height:30}); | 
 |  | 
 | </script> |