change style to header in html table - html

Question

I am learning css writing styles for an html table and I was wondering how I can remove the borders of the blank cell for the first row of my header, in addition to rounding the edges for the cells estimated amount and total.
I leave the html and css in addition to a thread of reproduction:
table {
border: 1px solid #ccc;
border-collapse: collapse;
margin: 0;
padding: 0;
width: 100%;
table-layout: fixed;
}
.blank {
background-color: #FFFFFF;
}
table tr {
background-color: #f8f8f8;
border: 2px solid #ddd;
padding: .35em;
}
table th,
table td {
padding: .625em;
text-align: center;
}
table th {
font-size: .85em;
letter-spacing: .1em;
text-transform: uppercase;
}
<table>
<thead>
<tr>
<th class="blank"></th>
<th colspan="2">estimated amount</th>
<th>total</th>
</tr>
<tr>
<th scope="col">Account</th>
<th scope="col">Expense</th>
<th scope="col">Income</th>
<th scope="col">Diff</th>
</tr>
</thead>
<tbody>
<tr>
<td data-label="Account">Visa - 3412</td>
<td data-label="Expense">$3,190</td>
<td data-label="Income">$1,000</td>
<td data-label="Diff">$2,190</td>
</tr>
<tr>
<td data-label="Account">Visa - 3412</td>
<td data-label="Expense">$5,000</td>
<td data-label="Income">$1,000</td>
<td data-label="Diff">$4,000</td>
</tr>
<tr>
<td data-label="Account">Visa - 3412</td>
<td data-label="Expense">$7,000</td>
<td data-label="Income">$4,000</td>
<td data-label="Diff">$3,000</td>
</tr>
</tbody>
</table>

Answer 1

this is a tricky one because applying border-radius while having the value of border-collapse set to collapse will not work the way you wanted it to.
My solution for you is to create your borders using CSS like this :
table {
border-collapse: separate;
border-spacing: 0;
margin: 0;
padding: 0;
width: 100%;
table-layout: fixed;
}
th ,td {
border-right:2px solid #ddd;
border-bottom: 2px solid #ddd;
background-color: #f8f8f8;
padding: .35em;
}
#tr1 th:last-child {
border-top: 2px solid #ddd;
}
#tr1 th:nth-child(2) {
border-left: 2px solid #ddd;
border-top: 2px solid #ddd;
}
#tr2 th:first-child{
border-top: 2px solid #ddd;
}
#tr2 th:first-child{
border-left: 2px solid #ddd;
}
tr td:first-child{
border-left: 2px solid #ddd;
}
.blank {
background-color: #FFFFFF;
border: none;
}
.estimatedAmountClass {
border-top-left-radius: 40px;
}
.totalClass {
border-top-right-radius: 40px;
}
table th,
table td {
padding: .625em;
text-align: center;
}
table th {
font-size: .85em;
letter-spacing: .1em;
text-transform: uppercase;
}
<table >
<thead>
<tr id="tr1">
<th class="blank"></th>
<th class="estimatedAmountClass" colspan="2">estimated amount</th>
<th class="totalClass">total</th>
</tr>
<tr id="tr2">
<th scope="col">Account</th>
<th scope="col">Expense</th>
<th scope="col">Income</th>
<th scope="col">Diff</th>
</tr>
</thead>
<tbody>
<tr>
<td data-label="Account">Visa - 3412</td>
<td data-label="Expense">$3,190</td>
<td data-label="Income">$1,000</td>
<td data-label="Diff">$2,190</td>
</tr>
<tr>
<td data-label="Account">Visa - 3412</td>
<td data-label="Expense">$5,000</td>
<td data-label="Income">$1,000</td>
<td data-label="Diff">$4,000</td>
</tr>
<tr>
<td data-label="Account">Visa - 3412</td>
<td data-label="Expense">$7,000</td>
<td data-label="Income">$4,000</td>
<td data-label="Diff">$3,000</td>
</tr>
</tbody>
</table>