:root {
    --bg-color: #f5f5f5;
    --text-color: #333;
    --card-bg: white;
    --input-bg: white;
    --input-border: #ddd;
    --button-bg: #0066cc;
    --button-text: white;
    --button-hover: #0052a3;
    --label-color: #333;
    --radio-color: #0066cc;
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg-color: #1a1a1a;
        --text-color: #e0e0e0;
        --card-bg: #2d2d2d;
        --input-bg: #333;
        --input-border: #444;
        --button-bg: #4da6ff;
        --button-text: #1a1a1a;
        --button-hover: #6db3ff;
        --label-color: #e0e0e0;
        --radio-color: #4da6ff;
    }
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
    min-height: 100vh;
    padding: 20px;
}

.centered {
    display: flex;
    justify-content: center;
    align-items: center;
}

.vstack {
    display: flex;
    flex-direction: column;
}

.hstack {
    display: flex;
    flex-direction: row;
}

input[type="url"]:focus {
    outline: none;
    border-color: var(--radio-color);
    box-shadow: 0 0 0 2px var(--radio-color);
}

input[type="submit"]:hover {
    background: var(--button-hover);
}

.radio-group {
    display: flex;
    gap: 1.5rem;
    flex-wrap: wrap;
    justify-content: center;
}

.radio-group label {
    color: var(--label-color);
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.radio-group input[type="radio"] {
    appearance: none;
    width: 1rem;
    height: 1rem;
    border: 2px solid var(--input-border);
    border-radius: 50%;
    background: var(--input-bg);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: border-color 0.2s, background 0.2s;
    flex-shrink: 0;
}

.radio-group input[type="radio"]:checked {
    border-color: var(--radio-color);
}

.radio-group input[type="radio"]:checked::before {
    content: '';
    width: 0.5rem;
    height: 0.5rem;
    border-radius: 50%;
    background: var(--radio-color);
}

.radio-group input[type="radio"]:focus {
    outline: none;
    box-shadow: 0 0 0 2px var(--radio-color);
}

.radio-group input[type="radio"]:hover {
    border-color: var(--radio-color);
}

#advanced-options summary::-webkit-details-marker {
    display: none;
}

#advanced-options summary::before {
    content: '▶';
    font-size: 1rem;
    line-height: 1;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 1rem;
    height: 1rem;
    color: var(--label-color);
    transform: rotate(0deg);
    transform-origin: center;
    transition: transform 0.2s;
    flex-shrink: 0;
}

#advanced-options[open] summary::before {
    transform: rotate(90deg);
}

#options-grid .option-group.full-width {
    grid-column: 1 / -1;
}

#options-grid .option-group label {
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--label-color);
}

#options-grid .option-group input[type="number"],
#options-grid .option-group textarea {
    padding: 0.5rem;
    border: 1px solid var(--input-border);
    border-radius: 0.25rem;
    background: var(--input-bg);
    color: var(--text-color);
    font-size: 0.875rem;
    font-family: inherit;
    width: 100%;
    box-sizing: border-box;
}

#options-grid .option-group textarea {
    resize: vertical;
    min-height: 60px;
    font-family: monospace;
}

#options-grid .option-group input[type="number"]:focus,
#options-grid .option-group textarea:focus {
    outline: none;
    border-color: var(--radio-color);
    box-shadow: 0 0 0 2px var(--radio-color);
}

.checkbox-group {
    display: flex;
    align-items: flex-start;
}

.checkbox-label {
    display: flex;
    align-items: flex-start;
    gap: 0.5rem;
    cursor: pointer;
    font-size: 0.875rem;
    color: var(--label-color);
    font-weight: normal;
}

.checkbox-label input[type="checkbox"] {
    width: 1rem;
    height: 1rem;
    margin-top: 0.125rem;
    accent-color: var(--radio-color);
    flex-shrink: 0;
}

.tab-selector {
    display: flex;
    gap: 0;
    margin-bottom: 0.5rem;
    border-radius: 0.25rem;
    overflow: hidden;
    background: var(--input-border);
    width: fit-content;
}

.tab-btn {
    padding: 0.375rem 1rem;
    border: none;
    background: transparent;
    color: var(--label-color);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: background 0.2s, color 0.2s;
}

.tab-btn.active {
    background: var(--radio-color);
    color: var(--button-text);
}

.btn,
input[type="submit"] {
    background: var(--button-bg);
}

.btn:hover {
    background: var(--button-hover);
}

#advanced-options li {
    margin-top: 0.5rem;
}

#event-options summary::-webkit-details-marker {
    display: none;
}

#event-options summary::before {
    content: '\25B6\FE0E';
    font-size: 1rem;
    line-height: 1;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 1rem;
    height: 1rem;
    color: var(--label-color);
    transform: rotate(0deg);
    transition: transform 0.2s;
    flex-shrink: 0;
}

#event-options[open] summary::before {
    transform: rotate(90deg);
}