Как сформировать набор div в форме пирамиды, как дерево?

Если у меня есть следующая структура HTML:

 <div class = "slots-container">
            <div class = "slot"></div>
            <div class = "slot"></div>
            <div class = "slot"></div>
            <div class = "slot"></div>
            <div class = "slot"></div>
            <div class = "slot"></div>
</div>

Следующий CSS:

  <style>
  .slots-container {
        display: grid;
        grid-template-columns: repeat(3, 1fr);
        grid-gap: 5px;
    }


        .slot {
            border: 2px dashed #ccc;
            padding: 5px;
            min-height: 300px;
            position: relative;
            cursor: pointer;
            transition: background-color 0.3s ease;
            display: flex;
            align-items: center;
            justify-content: center;
        }

            .slot:nth-child(3) {
                background: linear-gradient(to bottom right, #e66465, #9198e5);
            }

            .slot:nth-child(2),
            .slot:nth-child(1) {
                background: linear-gradient(to top left, #EAEAEA, #C4C4C4);
            }

            .slot:nth-child(4),
            .slot:nth-child(5),
            .slot:nth-child(6) {
                background: linear-gradient(to top left, #D9D9D9, #ADADAD);
            }


            .slot:hover {
                background-color: #f0f0f0;
            }

            .slot::before {
                content: "Drop Expert Card Here";
                position: absolute;
                top: 1px;
                left: 1px;
                width: 100%;
                height: 40px;
                background-color: #ffd700;
                color: #fff;
                font-size: 14px;
                font-weight: bold;
                display: flex;
                align-items: center;
                justify-content: center;
                font-family: inherit;
                color: black;
                border-bottom: 1px;
                border-color: dimgrey;
                margin-bottom: 5px;
            }

            .slot:nth-child(3)::before {
                content: "خبير صناعة فئة-أ";
                background-color: #ffd700;
                text-align: center;
            }

            .slot:nth-child(2)::before,
            .slot:nth-child(1)::before {
                content: "خبير صناعة فئة-ب";
                background-color: #c0c0c0;
                text-align: center;
            }

            .slot:nth-child(4)::before,
            .slot:nth-child(5)::before,
            .slot:nth-child(6)::before {
                content: "خبير صناعة فئة-ج";
                background-color: #cd7f32;
                text-align: center;
            }


        #temp_emp {
            display: flex;
            align-items: center;
            justify-content: center;
            min-height: 280px;
            background-color: #f9f9f9;
            border: 2px dashed #ccc;
        }

        .placeholder1 {
            position: relative;
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            padding: 5px;
            text-align: center;
            border: 2px dashed #999;
            background-color: #f9f9f9;
        }

        .placeholder-text {
            color: #999;
            font-weight: bold;
            font-size: 14px;
            margin-bottom: 10px;
        }

        .arrow-icon {
            width: 20px;
            height: 20px;
            background-color: #999;
            border-radius: 50%;
            margin-bottom: 10px;
        }

        .placeholder1:hover {
            background-color: #f0f0f0;
        }

        .placeholder1:before {
            font-size: 1.2rem;
            color: #888;
            opacity: 0.6;
        }


        .temp-emp-card {
            width: 250px;
            height: 250px;
            border: 2px solid #999;
            margin: 5px;
            background-color: #fff;
        }

        .card {
            background-color: #f8f8f8;
            border-radius: 8px;
            box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
            padding: 1px;
            text-align: center;
            transition: background-color 0.3s ease;
        }

            .card:hover {
                background-color: #f0f0f0;
            }

        .emp-photo {
            margin-bottom: 15px;
        }

            .emp-photo img {
                width: 130px;
                height: 130px;
                border-radius: 50%;
                object-fit: cover;
                border: 4px solid #fff;
                box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
            }

        .card-title {
            font-size: 15px;
            font-weight: bold;
            margin-bottom: 5px;
            margin-top: 5px;
            padding: 8px 16px;
            background-color: #e2e2e2;
            color: #333;
            border-radius: 20px;
            display: inline-block;
        }

        .card-text {
            font-size: 14px;
            color: #888;
        }

        .delete-button {
            position: absolute;
            top: 5px;
            right: 5px;
            font-size: 1.5rem;
            color: #dc3545;
            cursor: pointer;
        }

        .details-button {
            position: absolute;
            top: 5px;
            left: 5px;
            font-size: 1.5rem;
            color: #dc3545;
            cursor: pointer;
        }

        .card-body {
            padding: 1px;
        }
    </style>

Я хочу, чтобы слоты в форме пирамиды выглядели так. Как это сделать, сохраняя тот же HTML:

                                slot:nth-child(3)
                       slot:nth-child(1)   slot:nth-child(2)
              slot:nth-child(4)   slot:nth-child(5) slot:nth-child(6)