:root {
    --bg-color: #121212;
    --panel-bg: #1e1e1e;
    --text-primary: #e0e0e0;
    --accent: #bb86fc;
    --accent-hover: #9c27b0;
    --border: #333;
}

body {
    background-color: var(--bg-color);
    color: var(--text-primary);
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    margin: 0;
    padding: 2rem;
    display: flex;
    justify-content: center;
}

.container {
    width: 100%;
    max-width: 800px;
    background-color: var(--panel-bg);
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.3);
    position: relative;
    z-index: 9999;
}

header {
    text-align: center;
    margin-bottom: 2rem;
}

h1 {
    color: var(--accent);
    margin: 0 0 0.5rem 0;
}

.bridge-controls {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    margin-bottom: 2rem;
}

textarea {
    width: 100%;
    background-color: #2c2c2c;
    color: #fff;
    border: 1px solid var(--border);
    border-radius: 4px;
    padding: 1rem;
    font-family: monospace;
    font-size: 1rem;
    resize: vertical;
    position: relative;
    z-index: 100;
    user-select: auto;
}

textarea:focus {
    outline: none;
    border-color: var(--accent);
}

.btn {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 4px;
    font-weight: bold;
    cursor: pointer;
    transition: background-color 0.2s;
    align-self: flex-start;
}

.btn.primary {
    background-color: var(--accent);
    color: #000;
}

.btn.primary:hover {
    background-color: var(--accent-hover);
    color: #fff;
}

.iframe-container {
    border: 1px solid var(--border);
    border-radius: 4px;
    overflow: hidden;
    background-color: #fff;
    /* Strudel REPL has its own background, usually light or dynamic */
}

.iframe-container h2 {
    background-color: var(--border);
    margin: 0;
    padding: 0.5rem 1rem;
    font-size: 1rem;
    color: #fff;
}

iframe {
    display: block;
}