body {
    font-family: Arial, sans-serif;
    background-color: #1e1e1e;
    color: #d4d4d4;
    line-height: 1.6;
    padding: 20px;
}

input[type="text"] {
    background-color: #3c3c3c;
    color: #d4d4d4;
    border: 1px solid #555;
    padding: 8px;
    border-radius: 4px;
    width: 300px;
}

button {
    background-color: #0e639c;
    color: white;
    padding: 10px 15px;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 16px;
    margin-top: 20px;
}

button:hover {
    background-color: #1177bb;
}

#examenForm {
    max-width: 900px;
    margin: 0 auto;
}

fieldset {
    border: 1px solid #555;
    border-radius: 8px;
    margin-bottom: 25px;
    padding: 20px;
}

legend {
    color: #4ec9b0;
    font-size: 1.2em;
    font-weight: bold;
    padding: 0 10px;
}

fieldset:first-of-type div {
    display: flex;
    justify-content: space-between;
    gap: 20px;
}

fieldset:first-of-type div > div {
    flex: 1;
}

fieldset:first-of-type label,
fieldset:first-of-type input {
    display: block;
    width: 95%;
}

.contenedor-respuestas {
    display: grid;
    grid-template-columns: 100px 1fr;
    gap: 15px;
    align-items: center;
    margin-top: 20px;
}

.contenedor-respuestas label {
    font-weight: bold;
    text-align: right;
}

.contenedor-respuestas input {
    width: 90%;
}

.arbol-visual {
    background-color: #252526;
    border: 1px solid #444;
    border-radius: 5px;
    padding: 20px;
    margin-bottom: 20px;
    overflow-x: auto;
}

.arbol-visual ul {
    position: relative;
    padding: 1em 0;
    white-space: nowrap;
    margin: 0 auto;
    text-align: center;
}
.arbol-visual ul::after {
    content: '';
    display: table;
    clear: both;
}

.arbol-visual li {
    display: inline-block;
    vertical-align: top;
    text-align: center;
    list-style-type: none;
    position: relative;
    padding: 1em 0.5em 0 0.5em;
}

.arbol-visual li::before,
.arbol-visual li::after {
    content: '';
    position: absolute;
    top: 0;
    right: 50%;
    border-top: 2px solid #666;
    width: 50%;
    height: 1em;
}
.arbol-visual li::after {
    right: auto;
    left: 50%;
    border-left: 2px solid #666;
}
.arbol-visual li:only-child::after,
.arbol-visual li:only-child::before {
    display: none;
}
.arbol-visual li:only-child {
    padding-top: 0;
}
.arbol-visual li:first-child::before,
.arbol-visual li:last-child::after {
    border: 0 none;
}
.arbol-visual li:last-child::before {
    border-right: 2px solid #666;
    border-radius: 0 5px 0 0;
}
.arbol-visual li:first-child::after {
    border-radius: 5px 0 0 0;
}
.arbol-visual ul ul::before {
    content: '';
    position: absolute;
    top: 0;
    left: 50%;
    border-left: 2px solid #666;
    width: 0;
    height: 1em;
}
.arbol-visual li span {
    border: 2px solid #666;
    padding: 0.5em;
    font-family: monospace;
    font-size: 1.1em;
    display: inline-block;
    border-radius: 5px;
    background-color: #333;
    color: #d4d4d4;
    min-width: 30px;
    text-align: center;
}