CSS: Positioning child table using width percentage?

Question

Page content , CSS Stylesheet

When you visit the page content link, take the sample code below and submit it. You will notice that the child table source_code does not stretch all the way to the right. If I add width: 100% to the syntax_table class, it fixes the problem but the source_code table aligns right and I can't make it move to the left.

I've spent about 2 hours trying to fix it, I need some help now.

Here is some C# sample code:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;
using Microsoft.Phone.Controls;

namespace Test1
{
    public partial class MainPage : PhoneApplicationPage
    {
        // Constructor
        public MainPage()
        {
            InitializeComponent();
        }

        /// <summary>
        /// Calculate method.
        /// </summary>
        /// <param name="sender">Sender</param>
        /// <param name="e">Event Arguments</param>
        private void btnCalculate_Click(object sender, RoutedEventArgs e)
        {
            double weight;
            int heightf, heighti;

            Double.TryParse(this.txtWeight.Text, out weight);
            Int32.TryParse(this.txtHeightF.Text, out heightf);
            Int32.TryParse(this.txtHeightI.Text, out heighti);

            if (!(heightf >= 1))
                MessageBox.Show("A person is at least 1 foot tall.");
            else if (!(weight >= 1.0))
                MessageBox.Show("A person cannot weigh nothing.");
            else if (heightf >= 12)
                MessageBox.Show("A person is not taller than 12 feet.");
            else
            {
                double kg = weight * 0.45359237;
                int height = heighti + (heightf * 12);
                double bmi = weight / (height * height) * 703;
                double gbmi = Math.Round(bmi, 1);
                this.txtBMI.Text = bmi.ToString("n1");
            }
        }
    }
}

Answer 1

That's because the 2 table cells on .syntax_table are sizing themselves, which your browser is going to guess on. You need to at least set a width of the table cell containing line_numbers

<table class="syntax_table">
     <tr>
           <td class="lines"><table class="line_numbers">...</table></td>
           <td><table class="source_code">...</table></td>
     </tr>
</table>

Styles

.source_code { width: 100%; } // add this to give source_code full width of it's cell
.lines { width: 50px } // or set to a percentage, then .code should take up the rest