纯Css实现三角形、气泡框的三角形

上下左右箭头

效果图片

HTML

  	
    <div class="triangle_border_up">div>
    
    <div class="triangle_border_down">div>
    
    <div class="triangle_border_left">div>
    
    <div class="triangle_border_right">div>

Css

        /*向上*/
        .triangle_border_up {
            width: 0;
            height: 0;
            border-width: 0 30px 30px;
            border-style: solid;
            border-color: transparent transparent #FFCCCC;
            				/*透明         透明       黄*/
            margin: 40px auto;
            position: relative;
        }

        /*向下*/
        .triangle_border_down {
            width: 0;
            height: 0;
            border-width: 30px 30px 0;
            border-style: solid;
            border-color: #FFCCCC transparent transparent;
            				/*黄 	透明         透明 */
            margin: 40px auto;
            position: relative;
        }

        /*向左*/
        .triangle_border_left {
            width: 0;
            height: 0;
            border-width: 30px 30px 30px 0;
            border-style: solid;
            border-color: transparent #FFCCCC transparent transparent;
            				/*透明       黄   透明        透明 */
            margin: 40px auto;
            position: relative;
        }

        /*向右*/
        .triangle_border_right {
            width: 0;
            height: 0;
            border-width: 30px 0 30px 30px;
            border-style: solid;
            border-color: transparent transparent transparent #FFCCCC;
            				/*透明       透明        透明         黄*/
            margin: 40px auto;
            position: relative;
        }

左上、左下、右上、右下箭头

效果图片

HTML

 	
    <div class="triangle_border_nw">div>
    
    <div class="triangle_border_sw">div>
    
    <div class="triangle_border_ne">div>
    
    <div class="triangle_border_se">div>

Css

        /* 左上 */
        .triangle_border_nw {
            width: 0;
            height: 0;
            border-width: 30px 30px 0 0;
            border-style: solid;
            border-color: #CCCCFF transparent transparent transparent;
            margin: 40px auto;
            position: relative;
        }

        /* 左下 */
        .triangle_border_sw {
            width: 0;
            height: 0;
            border-width: 30px 0 0 30px;
            border-style: solid;
            border-color: transparent transparent transparent #CCCCFF;
            margin: 40px auto;
            position: relative;
        }

        /* 右上  */
        .triangle_border_ne {
            width: 0;
            height: 0;
            border-width: 30px 0 0 30px;
            border-style: solid;
            border-color: #CCCCFF transparent transparent transparent;
            margin: 40px auto;
            position: relative;
        }

        /* 右下 */
        .triangle_border_se {
            width: 0;
            height: 0;
            border-width: 30px 30px 0 0;
            border-style: solid;
            border-color: transparent #CCCCFF transparent transparent;
            margin: 40px auto;
            position: relative;
        }

气泡框的三角形

效果图片

HTML

 	<div class="test_triangle_border">
        <div class="popup">
            纯CSS写带边框的三角形
        div>
    div>

Css

		.test_triangle_border {
            width: 200px;
            margin: 0 auto 20px;
            position: relative;
        }

        .test_triangle_border .popup {
            width: 100px;
            background: #99FF99;
            padding: 10px 20px;
            color: #333;
            border-radius: 4px;
            position: absolute;
            top: 30px;
            left: 30px;
            border: 1px solid #333;
        }

        .test_triangle_border .popup::before {
            content: '';
            width: 0px;
            height: 0px;
            border-width: 0 10px 10px;
            border-style: solid;
            border-color: transparent transparent #333;
            left: 50%;
            top: -10px;
            position: absolute;
            margin-left: -10px;
        }

        .test_triangle_border .popup::after {
            content: '';
            width: 0px;
            height: 0px;
            border-width: 0 10px 10px;
            border-style: solid;
            border-color: transparent transparent #99FF99;
            left: 50%;
            top: -9px;
            position: absolute;
            margin-left: -10px;
        }