.code-runner {
    width: 100%;
    margin: 15px 0;
    background: #1e1e1e;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 0 15px rgba(0,0,0,0.5);
}
.toolbar {
    background: #111;
    padding: 10px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.toolbar select, .toolbar button {
    background: #333;
    color: #fff;
    border: none;
    padding: 6px 12px;
    border-radius: 5px;
    font-size: 14px;
    cursor: pointer;
}
.toolbar button:hover {
    background: #444;
}
#editor {
    height: 250px;
    width: 100%;
}
#code-output {
    width: 100%;
    height: 250px;
    border: none;
    background: #fff;
}