body {
    max-width: 800px;
    margin: auto;
    background-color: #DDDDDD;
}
div.form {
    border: 1px solid darkblue;
    padding: 5px;
    margin-right: 20px;
}
div.all {
    background-color: white;
    border-radius: 10px;
    padding: 10px;
}
li {
    padding-top: 10px;
}
h1 {
    text-align: center;
}
label {
    margin-right: 10px;
}
table, tr, td {
    border: 1px solid black;
    border-collapse: collapse;
    padding: 5px;
}
thead td, thead th {
    background-color: darkslategray;
    color: white;
    font-weight: bold;
    text-align: center;
}
p {
    line-height: normal;
    margin-bottom: 0;
}
table {
    margin: auto;
}
table.noborder, table.noborder tr, table.noborder td {
    margin: initial;
    border: none;
}
h2, h3, h4 {
    margin-top: 1em;
}
.attempts {
    color: gray;
    font-size: 60%;
}

.tool {
    position: relative;
}

.tip {
    position: absolute;
    visibility: hidden;
    z-index: 10;
    background-color: white;
    width: 230px;
    height: 60px;
    border: 1px solid black;
    border-radius: 5px;
}

.tool .tip {
    font-size: 70%;
}

.tool:hover .tip, .attempts:hover .tip{
    visibility: visible;
}

.reg a {
    color: darkgreen;
}

.unreg a {
    color: red;
}

details {
    display: block;
}

.warning {
    color: red;
    font-weight: bolder;
    background-color: #FFDDDD;
}

iframe {
    width: 100%;
    height: 440px;
}