Padding changes width inside table

问题

I have a table that has fixed width, and inside the table I need to have some inputs(text) that has the same width of the table, but I don't want the text of the inputs to be at left:0, I want them to have some padding from the left. But when I put the padding to those inputs the width changes to more than 100%.

Here the HTML:

<table cellspacing="25">
    <tr>
        <td><input type="text" placeholder="lalala"></td>
    </tr>
</table>

And this is the CSS.

table {
    background-color: red;
    width: 300px;
}
table input {
    width: 100%;
    padding-left: 10px;
}

How can I ensure that the width of the input element is 100% the width of the table cell?

Check the fiddle

回答1:

add this css rule to your input:

box-sizing: border-box;

The box-sizing property is used to tell the browser what the sizing properties (width and height) should include.

Should they include the border-box? Or just the content-box.

Here is a snippet:

table {
    background-color: red;
    width: 300px;
}
table input {
    width: 100%;
    padding-left: 10px;
    box-sizing: border-box;
}

<table cellspacing="25">
    <tr>
        <td><input type="text" placeholder="lalala"></td>
    </tr>
</table>

回答2:

You can use box-sizing: border-box; (support) in which "The width and height properties include the padding and border, but not the margin." in your CSS for the specified elements as @1l13v has done in his answer:

table input {
   box-sizing: border-box;
}

Or you can use the calc function (support):

table input {
    width: calc( 100% - 10px );
}

回答3:

Another option would be to calculate the width and padding of the input with percentages. If the sum of the content, border, margin, and padding of the element is 100% then it should fit how you would like. See the box-model concept in css: http://www.w3schools.com/css/css_boxmodel.asp

All HTML elements can be considered as boxes. In CSS, the term "box model" is used when talking about design and layout.

The CSS box model is essentially a box that wraps around HTML elements, and it consists of: margins, borders, padding, and the actual content.

The box model allows us to add a border around elements, and to define space between elements.

For example, if you want 10% padding on the left then the width should be 90%.

See this fiddle: http://jsfiddle.net/3nk07y1x/1/

CSS:

table {
    background-color: red;
    width: 300px;
}
table input { 
    width: 90%;
    padding-left: 10%;
}

回答4:

The width of the table will be the width plus the padding. Try subtracting some percentage points from the width like this:

table input {
  width: 90%;
  padding-left: 1em;
}

I would also change pixels to ems, because these are a little bit more stable on different screen resolutions.

来源：https://stackoverflow.com/questions/32854597/padding-changes-width-inside-table

标签

html

css

html-table

padding