* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: Cambria, Cochin, Georgia, Times, Times New Roman, serif;
}

.wrapper {
    margin: 5px auto;
    padding: 0;
}

.tabledangnhap {
    margin: auto;
    padding: 10px;
    width: 350px;
    box-shadow: 5px 10px 18px grey;
}

    .tabledangnhap tr td {
        padding: 5px;
    }

caption {
    margin: auto;
    text-align: center;
    font-size: 20px;
    color: forestgreen;
    font-weight: bold;
    background-color: azure;
    padding: 10px;
    margin-bottom: 10px;
}

.tabledangnhap img {
    width: 30px;
    vertical-align: middle;
    margin-right: 5px;
}

.tabledangnhap span {
    color: green;
    font-weight: bold;
}

.tabledangnhap input[type=text], input[type=password] {
    width: 100%;
    padding: 5px;
    outline: none;
    border: none;
    border-bottom: 1px dotted green;
}

.tabledangnhap input[type=submit] {
    padding: 10px;
    font-weight: bold;
    background-color: green;
    color: white;
    border-radius: 7px;
    margin-right: 30px;
    margin-top: 10px;
}

    .tabledangnhap input[type=submit]:hover {
        background-color: aliceblue;
        color: green;
        cursor: pointer;
    }

.trolaitrangchu {
    text-decoration: underline;
    color: blue;
    font-size: 13px;
}

    .trolaitrangchu:hover {
        color: #ff6a00;
    }

.tabledangnhap .back-arrow {
    width: 20px;
    vertical-align: middle;
}

.tabledangnhap #reviewanhdaidien {
    text-align: center;
    width: 100px;
    margin-bottom: 10px;
}

.tabledangnhap .imguser {
    display: block;
    width: 100px;
    margin-left: auto;
    margin-right: auto;
    box-shadow: 2px 2px 2px gray;
}

.gradient-background {
    background: linear-gradient(251deg,#c32ceb,#155be1,#689781,#a6a21b,#72d869);
    background-size: 300% 300%;
    animation: gradient-animation 25s ease infinite;
}

@keyframes gradient-animation {
    0% {
        background-position: 0% 50%;
    }

    50% {
        background-position: 100% 50%;
    }

    100% {
        background-position: 0% 50%;
    }
}