CSS- can't resize text input

Question

It was probably asked before / someone had a similar problem, but I have been searching for a long time and couldn't find any solution to my problem.

I have a div called loginBox that is centred, and has a form in it. I want the text boxes in the form to take almost the entire width of the form (It should look like google's new sign in form).

I am setting the input's margin to auto and the width to 90% using css, but for some reason it has no effect. Even when I set the width to a number (i.e 200px), the width remains unchanged.

The only way I could make it work is increase the padding of the input to 100px, but this is both not responsive, and not a good practice.

This is the code I am using:

body {
  margin: 0;
  background-color: #EEEEEE
}

.menu {
  overflow: hidden;
  background-color: #333;
  position: fixed;
  top: 0;
  width: 100%;
  z-index: 1000;
}

.menu a {
  float: left;
  display: block;
  color: #f2f2f2;
  text-align: center;
  padding: 14px 16px;
  text-decoration: none;
  font-size: 17px;
}

.active {
  background-color: #4CAF50;
}

.pageMain {
  width: 100%;
  padding: 16px;
  margin-top: 70px;
  height=1500px;
}

.loginBox {
  display: table;
  margin: auto;
  width: 50%;
  background-color: white;
  box-shadow: 2px 2px lightgrey;
  padding: 25px;
}

input {
  margin: auto;
  width=90%;
  padding: 12px 20px;
  border: 1px solid #ccc;
  border-radius: 4px;
  box-sizing: border-box;
}

<div class="menu">
  <a class="active" href="index.html">Home</a>
  <a href="about.html">Grades</a>
  <a href="games.html">Behavior</a>
  <a href="utilities.html">Homework</a>
  <a href="tutorials.html">Learning Enviroments</a>
  <a href="tutorials.html">Time Table</a>
  <a href="tutorials.html">People</a>
  <a style="float: right" href="contact.html">Contact</a>
  <a style="float:right" href="contact.html">Login</a>

</div>

<div class="pageMain">

  <div class="loginBox">

    <h3>Sign in</h3>
    <h4>With your RSIS account</h4>

    <form>

      <input type="text" size="300" name="username" value="Email, RSIS username or id">

    </form>

  </div>

</div>

Screenshot of what I get right now

Answer 1

change:

width=90%;
height=1500px;

to:

width:90%;
height:1500px;

also use * { box-sizing: border-box;} for remove scrollbars.

Answer 2

Fix your width. Instead of = it should be :. Your code seems fine otherwise. And width: 100% works just the way you intended.

Also, as mentioned in the comments, It should be height: 1500px; in .pageMain

body {
  margin: 0;
  background-color: #EEEEEE
}

.menu {
  overflow: hidden;
  background-color: #333;
  position: fixed;
  top: 0;
  width: 100%;
  z-index: 1000;
}

.menu a {
  float: left;
  display: block;
  color: #f2f2f2;
  text-align: center;
  padding: 14px 16px;
  text-decoration: none;
  font-size: 17px;
}

.active {
  background-color: #4CAF50;
}

.pageMain {
  width: 100%;
  padding: 16px;
  margin-top: 70px;
  height: 1500px;
}

.loginBox {
  display: table;
  margin: auto;
  width: 50%;
  background-color: white;
  box-shadow: 2px 2px lightgrey;
  padding: 25px;
}

input {
  margin: auto;
  width:100%;
  padding: 12px 20px;
  border: 1px solid #ccc;
  border-radius: 4px;
  box-sizing: border-box;
}

<div class="menu">
  <a class="active" href="index.html">Home</a>
  <a href="about.html">Grades</a>
  <a href="games.html">Behavior</a>
  <a href="utilities.html">Homework</a>
  <a href="tutorials.html">Learning Enviroments</a>
  <a href="tutorials.html">Time Table</a>
  <a href="tutorials.html">People</a>
  <a style="float: right" href="contact.html">Contact</a>
  <a style="float:right" href="contact.html">Login</a>
</div>

<div class="pageMain">
  <div class="loginBox">
    <h3>Sign in</h3>
    <h4>With your RSIS account</h4>

    <form>
      <input type="text" size="300" name="username" value="Email, RSIS username or id">
    </form>
  </div>
</div>

Answer 3

the first look into your css file

height=1500px; // Why =, not :? <----- PageMain class

width=90%; // <---- same here in input class