Usei <div> para definir o tamanho do <flux:input>

[Frank K Hosaka]

arquivo resources > views > livewire > ldiario-lcto.blade.php (parcial)
<flux:field>
        <div class="w-[130px]"">
            <flux:input.group>
                <flux:input.group.prefix>Dia</flux:input.group.prefix>
                <flux:input type="date" wire:model="dia" wire:change="data"
                    onclick=this.showPicker() />
            </flux:input.group>
        </div>
        <div class="w-[130px]">
            <flux:input.group>
                <flux:input.group.prefix>Lçto</flux:input.group.prefix>
                <flux:input wire:model="lcto" onclick=this.showPicker() />
            </flux:input.group>
        </div>
        <div class="flex items-center">
            <div class="w-[130px]">
                <flux:input.group>
                    <flux:input.group.prefix>ContaD</flux:input.group.prefix>
                    <flux:input wire:model="ctaD" wire:click="abrirModal('ctaD')" />
                </flux:input.group>
            </div>
            <div class='px-2'>{{$descD}}</div>
        </div>
        <div class="flex items-center">
            <div class="w-[130px]">
                <flux:input.group>
                    <flux:input.group.prefix>ContaC</flux:input.group.prefix>
                    <flux:input wire:model="ctaC" wire:click="abrirModal('ctaC')" />
                </flux:input.group>
            </div>
            <div class='px-2'>{{$descC}}</div>
        </div>
        <div class="w-[130px]">
            <flux:input.group>
                <flux:input.group.prefix>Valor</flux:input.group.prefix>
                <flux:input wire:model="valor" />
            </flux:input.group>
        </div>
        <div>
            <flux:input.group>
                <flux:input.group.prefix>Histórico</flux:input.group.prefix>
                <flux:input wire:model="hist" />
            </flux:input.group>
        </div>
        <div class="w-[130px]">
            <flux:button wire:click="salvar" variant="primary">
                Registrar
            </flux:button>
        </div>
    </flux:field>