*{
    margin: 0;
    padding: 0;
    /*标准盒子 */
    box-sizing: border-box;
}
body,html{
    font-family: Arial, Helvetica, sans-serif;
    background: #f8f8f8;
    /* 锁定背景： */
    background-attachment: fixed;
    /* 弹性布局 */
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    height: 100%;
    margin:  0 auto;
}
h1{
    margin: 0.2rem;
    font-size: 1.2rem;
}

p{
    font-size: 1rem;
    line-height: 1.5rem;
    /* 字体变淡 */
    font-weight: 100;
    margin: 1.2rem 0;
    /* 字间距 */
    letter-spacing: 0.1rem;
}
span{
    font-size: 0.8rem;
    margin: 1.2rem 0;
}
a{
    color: #333;
    font-size: 1rem;
    /* 下划线消失 */
    text-decoration: none;
}

.container{
    /* 相对定位 */
    position: relative;
    background: #fff;
    border-radius: 10px;
    box-shadow: 0 14px 28px rgba(0, 0, 0, 0.25),0 10px 10px rgba(0, 0, 0, 0.22);
    padding: 0.6rem;
    width: 50rem;
    height: 35rem;
    /* 溢出隐藏 */
    overflow: hidden;
    max-width: 100vw;
    min-height: 70vh;
}
.form-container form{
    background: #fff;
    /* 弹性布局 */
    display: flex;
    flex-direction: column;
    padding: 0 1.8rem;
    height: 100%;
    justify-content: center;
    align-items: center;
}

.social-container{
    margin: 0.6rem 0;
}

.social-container a{
    border: 1px solid #eee;
    border-radius: 50%;
    display: inline-flex;
    justify-content: center;
    align-items: center;
    margin: 0 5px; 
    height: 1.8rem;
    width: 1.8rem;
}

.social-container a:hover{
    opacity: 0.8;
}

.form-container input{
    width: 100%;
    height: 2.2rem;
    text-indent: 1rem;
    border: 1px solid #ccc;
    /* 把input上左右边框取消 */
    border-left: none;
    border-right: none;
    border-top: none;
    /* 点击input边框消失 */
    outline: none;
    margin: 0.6rem 0;
}

/* 被选中时候缩小 */
.form-container button:active{
    transform: scale(0.95,0.95);
}

.form-container button{
    padding: 0.4rem 1rem;
    background: #417dff;
    color: white;
    border: 1px solid #fff;
    outline: none;
    /* 鼠标放上变小手 */
    cursor: pointer;
    width: 5rem;
    border-radius: 8px;
    transition: all 100ms ease-in;
    margin: 0.6rem 0;
    font-size: 0.6rem;
    padding: 0.5rem 0;
}

button#send_code{
    width: 100%;
}

button.ghost{
    background: transparent;
    border-color: #fff;
    border: 1px solid #fff;
    outline: none;
    cursor: pointer;
    width: 5rem;
    border-radius: 8px;
    transition: all 800ms ease-in;
    margin: 0.6rem 0;
    padding: 0.5rem 0;
    color: white;
    font-size: 0.6rem;
}
button.ghost:active{
    transform: scale(0.95,0.95);
}

.form-container{
    /* 绝对定位 */
    position: absolute;
    top: 0;
    height: 100%;
    transition: all 0.5s ease-in;

}

.sing-in-container{
    left: 0;
    width: 50%;
    z-index: 2;
}
.sign-up-container{
    left: 0;
    width: 50%;
    opacity: 0;
    z-index: 1;
}

.overlay{
    background: #417dff;
    width: 200%;
    height: 100%;
    position: relative;
    left: -100%;
    transition: all 0.6s ease-in-out;
    color: white;
}

.overlay-container{
    position: absolute;
    top: 0;
    right: 0;
    width: 50%;
    height: 100%; 
    overflow: hidden;   
    transition: all 0.6s ease-in-out;
    z-index: 99;
}

.overlay-pannel{
    position: absolute;
    top: 0;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    width: 50%;
    height: 100%;
    padding: 0 2.2rem;
}

.overlay-right{
    right: 0;
}

.container.right-panel-active .overlay-container{
    transform: translateX(-100%);
}
.container.right-panel-active .sing-in-container{
    transform: translateX(100%);
}
.container.right-panel-active .sign-up-container{
    transform: translateX(100%);
    opacity: 1;
    z-index: 5;
    transition: all 0.6s ease-in-out;
}

.container.right-panel-active .overlay{
    transform: translateX(50%);
}
.container.right-panel-active .overlay-left{
    transform: translateX(0);
    transition: all 0.6s ease-in-out;
}
.container.right-panel-active .overlay-right{
    transform: translateX(20%);
    transition: all 0.6s ease-in-out;
}