.background-theme-picker{display:flex;flex-wrap:wrap;gap:8px}
.background-theme-picker .button[aria-pressed="true"]{border-color:var(--action-text);background-color:var(--action-soft);color:var(--action-text)}
.background-picker-help{margin:12px 0 28px;color:var(--text-secondary);font-size:14px;line-height:20px}
.background-comparison{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px}
.background-comparison-card{min-width:0;border:1px solid var(--border-subtle);border-radius:var(--radius-lg);overflow:hidden;background:var(--surface-primary)}
.background-mode{display:flex;align-items:center;gap:8px;padding:12px 16px;border-bottom:1px solid var(--border-subtle);font-size:14px;line-height:20px}
.background-mode svg{width:20px;height:20px}
.background-theme-preview{min-height:280px;padding:24px;background-size:100% 100%}
.background-preview-header{display:flex;align-items:center;gap:10px;font-size:14px;font-weight:600}
.background-preview-mark{display:flex;align-items:center;justify-content:center;width:36px;height:36px;border:1px solid var(--border-subtle);border-radius:10px;background:var(--surface-primary);color:var(--action-text)}
.background-preview-mark svg{width:20px;height:20px}
.background-preview-title{margin-top:28px;font-size:24px;line-height:32px;font-weight:600}
.background-preview-copy{margin-top:4px;font-size:14px;line-height:20px;color:var(--text-secondary)}
.background-reading-cards{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px;margin-top:24px}
.background-reading-cards>div{padding:16px;border:1px solid var(--border-subtle);border-radius:10px;background-color:var(--surface-primary);background-image:var(--ambient-panel-image)}
.background-preview-line{display:block;height:6px;width:80%;border-radius:3px;background:var(--action-soft)}
.background-preview-line.short{width:55%;margin-top:8px;background:var(--border-subtle)}
.background-theme-note{margin-top:16px;font-size:14px;line-height:22px;color:var(--text-secondary)}
.background-theme-detail .codebox{margin-top:16px}
.background-copy-fallback{width:100%;height:320px;margin-top:16px}
@media(max-width:767px){.background-comparison{grid-template-columns:1fr}.background-theme-preview{min-height:260px;padding:20px}.background-theme-detail .section-heading{flex-wrap:wrap;gap:12px}}
@media(forced-colors:active),(prefers-contrast:more){.background-reading-cards>div{background-image:none}}