Add _device_serial() to read disk serials from /sys/class/block/{name}/device/serial and /sys/block/{name}/device/serial when lsblk cannot expose them in Docker containers. Update raid_status() to use sysfs fallback before defaulting to "—" for missing serials. Add .raid-disks 2-column grid with 6px gap, .raid-disk 7px/9px padding, .raid-disk small 1px top margin, and .raid-smart 85% opacity. Add mobile