¿Cómo puedo apuntar a una columna o fila específica en un diseño de cuadrícula CSS?

body {
  display: grid;
  grid-template-rows: 1fr 1fr 1fr;
  grid-template-columns: 1fr 1fr;
  grid-gap: 10px;
}

.item {
  background: #999;
}

<div class="item">
  <p>Customer Name</p>
  <p>Element 1 | Element 2</p>
</div>

<div class="item">
  <p>Right Justify</p>
  <p>Element 1 | Element 2</p>
</div>

<div class="item">
  <p>Customer Name</p>
  <p>Element 1 | Element 2</p>
</div>

<div class="item">
  <p>Customer Name</p>
  <p>Element 1 | Element 2</p>
</div>
<div class="item">
  <p>Customer Name</p>
  <p>Element 1 | Element 2</p>
</div>
<div class="item">
  <p>Customer Name</p>
  <p>Element 1 | Element 2</p>
</div>
<div class="item">
  <p>Customer Name</p>
  <p>Element 1 | Element 2</p>
</div>

.grid-container {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  grid-gap: 2px;
}

.grid-item {
  border: 1px solid black;
  padding: 5px;
}

.grid-row-wrapper {
  display: contents;
}

.grid-row-wrapper > .grid-item {
  background: skyblue;
}

<div class="grid-container">
  <div class="grid-item">1</div>
  <div class="grid-item">2</div>
  <div class="grid-item">3</div>
  <div class="grid-item">4</div>
  <div class="grid-item">5</div>
  <div class="grid-row-wrapper">
    <div class="grid-item">6</div>
    <div class="grid-item">7</div>
    <div class="grid-item">8</div>
    <div class="grid-item">9</div>
    <div class="grid-item">10</div>
  </div>
  <div class="grid-item">11</div>
  <div class="grid-item">12</div>
  <div class="grid-item">13</div>
  <div class="grid-item">14</div>
  <div class="grid-item">15</div>
  <div class="grid-item">16</div>
  <div class="grid-item">17</div>
  <div class="grid-item">18</div>
  <div class="grid-item">19</div>
  <div class="grid-item">20</div>
</div>

grid-container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  grid-template-rows: 1fr 1fr 1fr;
  grid-gap: 10px;
  padding: 10px;
  height: 50vh;
  background-color: gray;
}

grid-item {
  background-color: lightgreen;
}

grid-item:nth-child(2n) {
  border: 2px dashed red;
}

<grid-container>
  <grid-item></grid-item>
  <grid-item></grid-item>
  <grid-item></grid-item>
  <grid-item></grid-item>
  <grid-item></grid-item>
  <grid-item></grid-item>
</grid-container>

grid-container {
  display: grid;
  grid-template-columns: 1fr 1fr;
  grid-template-rows: 1fr 1fr 1fr 1fr;
  grid-gap: 10px;
  padding: 10px;
  height: 50vh;
  background-color: gray;
}

grid-item {
  background-color: lightgreen;
}

grid-item:nth-child(4n+3),grid-item:nth-child(4n) {
  border: 2px dashed red;
}

<grid-container>
  <grid-item></grid-item>
  <grid-item></grid-item>
  <grid-item></grid-item>
  <grid-item></grid-item>
  <grid-item></grid-item>
  <grid-item></grid-item>
  <grid-item></grid-item>
  <grid-item></grid-item>
</grid-container>

const wp = document.querySelector('.wrapper')
const config = {
  data :[{"Name":"John","Age":25,"Gender":"Male"},{"Name":"Emily","Age":33,"Gender":"Female"},{"Name":"Michael","Age":42,"Gender":"Male"},{"Name":"Sarah","Age":29,"Gender":"Female"},{"Name":"William","Age":37,"Gender":"Male"},{"Name":"Samantha","Age":26,"Gender":"Female"},{"Name":"Benjamin","Age":48,"Gender":"Male"},{"Name":"Elizabeth","Age":31,"Gender":"Female"},{"Name":"David","Age":45,"Gender":"Male"},{"Name":"Olivia","Age":28,"Gender":"Female"}],
  colors : ['255,0,0', '0,255,0', '0,0,255'],
  cols : 3,
  rows : 3,
  lastSelectedColumn: null
}

function getSelectorTexts(column, columns, rows, color){
  const index = (column + 1) % columns 
  const i = index  ? `+ ${index}` : ''
  return [
    `.wrapper div:nth-child(${columns}n${i})`, 
    `.wrapper div:nth-child(${column + 1})`, 
    `.wrapper div:nth-child(${(rows-1) * columns  + column + 1})`
  ]
}

function selectColumn(column){
  const stylesheet = document
    .querySelector('style[title="grid-wrapper"]')
  if (!stylesheet || column === null) return
  const rules = getSelectorTexts(column, config.cols,
     wp.children.length / config.cols, config.colors[column])
  let i = 2  
  for (const rule of rules){
    stylesheet.sheet.rules[i++].selectorText = rule
  }
}

document.querySelector('button').onclick = function(){
  if (config.rows > config.data.length -1) return
  Object.values(config.data[config.rows++])
    .map(e => Object.assign(document.createElement('div'),{textContent: e}))
    .forEach(e => wp.appendChild(e)) 
  selectColumn(config.lastSelectedColumn)
}

wp.onclick = function({target}){
  if (target.className !== "") return
  const index = Array.from(wp.children).indexOf(target)
  selectColumn(config.lastSelectedColumn = index % config.cols)
}

<style title="grid-wrapper">
  .wrapper {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    width: fit-content;
    background: #e5e5e5;
    color: black;
    margin: 10px;
  }
  .wrapper div {
    padding: 5px;
    border-width: 3px;
    border-color: transparent; 
    box-shadow: 1px 1px 1px  black;
  }

  .rule1 {
    border-width: 0px 3px 0 3px; 
    border-color: rgb(0, 0, 255);
    border-style: solid;
    background: rgba(0, 0, 255, .1);
  }

  .rule2 {
    border-width: 3px 3px 0 3px;
    border-color: rgb(0, 0, 255);
  }

  .rule2 {
    border-width: 0 3px 3px 3px; 
    border-color: rgb(0, 0, 255);
  }
</style>   
<p>Please, select a column, and click on `Add`</p>
<div class="wrapper">
  <div>Name</div>
  <div>Age</div>
  <div>Gender</div>
  <div>John</div>
  <div>25</div>
  <div>Male</div>
  <div>Emily</div>
  <div>33</div>
  <div>Female</div>
  <div>Michael</div>
  <div>42</div>
  <div>Male</div>
</div>
<button>Add</button>