#qtapp {
    background: #121212;
    color: #eee;
    font-family: sans-serif;
    max-width: 640px;
    margin: 2em auto;
    padding: 1em;
    border-radius: 8px;
    box-shadow: 0 0 12px #000;
}
.tabs {
    display: flex;
    justify-content: space-around;
    margin-bottom: 1em;
}
.tabs button {
    background: #222;
    color: #fff;
    padding: 0.5em 1.2em;
    border: none;
    border-radius: 5px;
    cursor: pointer;
}
.tab {
    display: none;
}
.tab.active {
    display: block;
}
input[type="text"], select, textarea {
    width: 100%;
    margin: 0.5em 0;
    padding: 0.5em;
    background: #1c1c1c;
    color: #fff;
    border: 1px solid #333;
    border-radius: 5px;
}
textarea {
    height: 200px;
    resize: vertical;
}
button {
    background: #444;
    color: #fff;
    padding: 0.5em 1em;
    border: none;
    border-radius: 5px;
    margin-top: 0.5em;
    cursor: pointer;
}
img {
    margin-top: 1em;
    max-width: 100%;
    border-radius: 5px;
}