dangnhap.css

            .div1 {
                margin: 0px;
                width: 85%;
                height: 98%;
                background-image: url(bia1.png);
                background-repeat: no-repeat;
                opacity: 0.8;
                position: absolute;
                right: 0px;
                left: 0px;
                margin-left: 8%;
                background-size: cover;
                background-position: center;
            }
            
            body {
                font-family: Arial, Helvetica, sans-serif;
                background: url(ocean-3605547__340.jpg);
                background-repeat: no-repeat;
                background-size: cover;
                min-height: 100vh;
                /*chiều cao tối thiểu bằng toàn màn hình*/
            }
            
            center {
                top: 10%
            }
            
            form {
                width: 26%;
                height: 73%;
                background-color: rgb(136, 33, 33);
                text-align: center;
                background-color: rgba(255, 255, 255, 0.1);
                position: relative;
                /*cho cai the me chua no va duoc can chinh*/
                top: 5%;
                left: 15%;
                border-radius: 50px;
            }
            
            .input1 {
                width: 80%;
                margin-top: 8%;
                height: 10%;
                border-radius: 10px;
                border: 1px;
                font-size: 18px;
            }
            
            .choose {
                display: flex;
                justify-content: space-between;
                margin: 20px 8% 0px 8%;
                text-decoration: none;
            }
            
            .btndangnhap {
                width: 80%;
                margin-top: 10%;
                height: 7%;
                border-radius: 10px;
                border: 1px;
                background-color: chocolate;
                font-size: 145%;
            }
            
            .btndangnhap:hover {
                border: 3px solid red;
            }
            
            .radiobtn {
                width: 5%;
                height: 5%;
                /*căn vị trí cho cái radionay bằng positon vơi vị trí tương đối*/
            }
            
            #bntswithApp {
                width: 100%;
                height: 60px;
                margin-top: 8%;
                display: flex;
                justify-content: space-around;
                align-items: center;
            }
            
            .btnIcon {
                height: 50%;
                width: 40%;
                border-radius: 50px;
                color: aliceblue;
                text-decoration: none;
                /* cách bỏ gạch chân cuar chữ cái hoặc thẻ a*/
                padding-top: 2.2%;
            }
            
            .facebook {
                background-color: rgb(10, 51, 165);
            }
            
            .google {
                background-color: indianred;
            }
            
            #sourc {
                /* cawn 1 chuaw be duowi nhng laij chung tam*/
                display: flex;
                justify-content: center;
                margin-bottom: 0px;
            }
            
            @media only screen and (max-width: 700px) {
                .div1 {
                    margin-left: 0;
                    width: 100%;
                    height: 100%;
                }
                form {
                    width: 70%;
                    height: auto;
                    margin-bottom: 0px;
                }
                h1 {
                    color: aqua;
                    font-size: 30px;
                }
                #sourc {
                    text-align: center;
                    margin-bottom: 0px;
                }
                .btnIcon {
                    width: 35%;
                    height: 45%;
                }
                .btndangnhap {
                    width: 70%;
                    margin-top: 10%;
                    height: 6%;
                }
                .input1 {
                    width: 80%;
                    margin-top: 8%;
                    height: 7%;
                    font-size: 15px;
                }
            }