.adapt_screen{width: 100%; max-width: 1920px; position: relative; margin: 0 auto;}
.adapt_screen img{width: 100%;}

.f-header .fheader{position: absolute; left: 53%; top: 40.2%; color: #fff;}
.f-header .fheader h2{font-size: 40px; line-height: 50px; margin-bottom: 30px;}
.f-header .fheader p{font-size: 22px;}

.across-des{position: absolute; width: 800px; text-align: center; left: 50%; margin-left: -400px; color: #595757; top: 6%;}
.across-des h2{line-height: 60px; font-size: 26px;}
.across-des p{font-size: 16px; line-height: 30px;}

.silica-des{position: absolute; left: 20.4%; top: 36.6%; color: #595757; width: 460px;}
.silica-des h2{line-height: 60px; font-size: 26px;}
.silica-des p{font-size: 16px;line-height: 30px;}

.convenient-des{color: #595757; position: absolute; left:66%; top: 30.9%;}
.convenient-des h2{line-height: 60px; font-size: 26px;}
.convenient-des p{font-size: 16px; line-height: 30px;}