Unable to remove white space from right in responsive design HTML/CSS

Issue

I am unable to remove the white space from right side when implementing responsive design. I have used flex box to implement most of the layout. The window responds accurately and content adjusts accordingly but when scrolled, there is space on the right always!

Hierarchy of classes:

----> container

--------> sidebar

----------------> name-profession

----------------> details

------------------------> contact-item

--------> content

HTML:

* {
  margin: 0;
  padding: 0;
  font-family: Roboto;
  box-sizing: border-box;
}

html,
body {
  height: 100%;
  background-color: #E5E6EA;
}

.container {
  display: flex;
  height: 100%;
}

@media screen and (max-width: 480px) {
  .container {
    flex-direction: column;
  }
}


/* Sidebar */

.sidebar {
  background-color: #FFF;
  flex: 1;
  margin-right: 20px;
  width: 400px;
  flex: initial;
}

@media screen and (max-width: 480px) {
  .sidebar {
    width: 100%;
    margin-bottom: 40px;
    margin-right: 0;
  }
}

.name-profession {
  background-color: #56b293;
  padding: 20px;
  display: flex;
  align-items: center;
  flex-direction: column;
  color: #fff;
}

.name {
  font-size: 40px;
  font-weight: bold;
}

.profession {
  font-size: 20px;
}

.details {
  padding: 40px;
}

@media screen and (max-width: 480px) {
  .details {
    width: 300px;
    margin: 0 auto;
    position: relative;
  }
  .contact-item {}
}

.contact {
  margin-bottom: 20px;
}

.contact-item {
  display: flex;
  width: 400px;
  margin-bottom: 20px;
}

.contact-text {
  margin-left: 10px;
  font-size: 15px;
}


/* End Sidebar */


/* Content */

.content {
  background-color: #fff;
  flex: 2;
}

@media screen and (max-width: 480px) {
  .content {
    width: 100%;
    margin-bottom: 40px;
  }
}


/* End Content */


/* Common */

.large-heading {
  font-size: 25px;
  text-transform: uppercase;
  font-weight: bold;
}

.heading {
  font-size: 20px;
  text-transform: uppercase;
  font-weight: bold;
}

.content-text {
  color: grey;
}

.circle-avatar {
  width: 40px;
  height: 40px;
  background-color: #56b293;
  border-radius: 50%;
  display: flex;
  justify-content: center;
  align-items: center;
}

.circle-avatar img {
  width: 30px;
  height: 30px;
  padding: 5px;
}

.dotted-separator {
  border-top: 3px dashed #E5E6EA;
  width: 100%;
}

.content-padding {
  padding: 40px;
}

<link href="https://fonts.googleapis.com/css?family=Roboto" rel="stylesheet">
<div class="container">
  <!--Sidebar-->
  <div class="sidebar">
    <div class="name-profession">
      <p class="name">Gurleen Sethi</p>
      <p class="profession">Software Developer</p>
    </div>

    <div class="details">
      <p class="contact large-heading">Contact</p>
      <div class="contact-item">
        <div class="circle-avatar">
          <img src="images/home.png">
        </div>
        <div class="contact-text">
          <p class="heading">Address</p>
          <p class="content-text">948 New Geeta Colony</p>
        </div>
      </div>

      <div class="contact-item">
        <div class="circle-avatar">
          <img src="images/calendar.png">
        </div>
        <div class="contact-text">
          <p class="heading">DATE OF BIRTH</p>
          <p class="content-text">18 August 1996</p>
        </div>
      </div>

      <div class="contact-item">
        <div class="circle-avatar">
          <img src="images/phone.png">
        </div>
        <div class="contact-text">
          <p class="heading">Phone</p>
          <p class="content-text">+91 72908 32506</p>
        </div>
      </div>

      <div class="contact-item">
        <div class="circle-avatar">
          <img src="images/mail.png">
        </div>
        <div class="contact-text">
          <p class="heading">Email</p>
          <p class="content-text">contactgurleensethi@gmail.com</p>
        </div>
      </div>

      <div class="contact-item">
        <div class="circle-avatar">
          <img src="images/world.png">
        </div>
        <div class="contact-text">
          <p class="heading">Website</p>
          <p class="content-text">www.thetechnocafe.com</p>
        </div>
      </div>
    </div>
  </div>

  <!--Content-->
  <div class="content">
    <div class="about content-padding">
      <p class="heading" style="margin-bottom: 20px;">About</p>
      <p class="content-text">Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book.
        It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged.</p>
    </div>

    <div class="dotted-separator"></div>
  </div>
</div>

Solution

Your .contact-item has width of 400px which on mobile creates the horizontal space. Change it to width: 100% and it should be okay.

Answered By - Kushtrim