+ ret += '.ann_box {'
+ ret += 'z-index: 5;'
+ ret += 'position: absolute;'
+ ret += 'border: 1px solid rgba(0,0,0,.1);'
+ ret += '}'
+ ret += '.ann_tag {'
+ ret += 'z-index: 10;'
+ ret += 'position: absolute;'
+ ret += 'font-size: 8px;'
+ ret += 'white-space: pre;'
+ ret += 'background: rgba(255,255,255,0.4);'
+ ret += '}'