CSS3 对话气泡

.chat-bubble {
    background-color: #ededed;
    border: 2px solid #666;
    font-size: 35px;
    line-height: 1.3em;
    margin: 10px auto;
    padding: 10px;
    position: relative;
    text-align: center;
    width: 300px;
    -moz-border-radius: 20px;
    -webkit-border-radius: 20px;
    -moz-box-shadow: 0 0 5px #888;
    -webkit-box-shadow: 0 0 5px #888;
    font-family: 'Bangers', arial, serif; 
}
.chat-bubble-arrow-border {
    border-color: #666 transparent transparent transparent;
    border-style: solid;
    border-width: 20px;
    height: 0;
    width: 0;
    position: absolute;
    bottom: -42px;
    left: 30px;
}
.chat-bubble-arrow {
    border-color: #ededed transparent transparent transparent;
    border-style: solid;
    border-width: 20px;
    height: 0;
    width: 0;
    position: absolute;
    bottom: -39px;
    left: 30px;
}