
Full HTML and CSS Code:
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Responsive Web Layout</title>
    <style>
        /* Base Styles */
        body {
            color: #6c757d;
            background-color: #f5f6f8;
            margin-top: 20px;
        }
        .card-box {
            background-color: #fff;
            background-clip: border-box;
            border: 1px solid #e7eaed;
            padding: 1.5rem;
            margin-bottom: 24px;
            border-radius: 0.25rem;
        }
        .avatar-xl {
            height: 6rem;
            width: 6rem;
        }
        .rounded-circle {
            border-radius: 50% !important;
        }
        .nav-pills .nav-link.active,
        .nav-pills .show > .nav-link {
            color: #fff;
            background-color: #1abc9c;
        }
        .nav-pills .nav-link {
            border-radius: 0.25rem;
        }
        .navtab-bg li > a {
            background-color: #f7f7f7;
            margin: 0 5px;
        }
        .nav-pills > li > a,
        .nav-tabs > li > a {
            color: #6c757d;
            font-weight: 600;
        }
        .mb-4,
        .my-4 {
            margin-bottom: 2.25rem !important;
        }
        .tab-content {
            padding: 20px 0 0 0;
        }
        .progress-sm {
            height: 5px;
        }
        .m-0 {
            margin: 0 !important;
        }
        .table .thead-light th {
            color: #6c757d;
            background-color: #f1f5f7;
            border-color: #dee2e6;
        }
        .social-list-item {
            height: 2rem;
            width: 2rem;
            line-height: calc(2rem - 4px);
            display: block;
            border: 2px solid #adb5bd;
            border-radius: 50%;
            color: #adb5bd;
        }
        .text-purple {
            color: #6559cc !important;
        }
        .border-purple {
            border-color: #6559cc !important;
        }
        .timeline {
            margin-bottom: 50px;
            position: relative;
        }
        .timeline:before {
            background-color: #dee2e6;
            bottom: 0;
            content: "";
            left: 50%;
            position: absolute;
            top: 30px;
            width: 2px;
            z-index: 0;
        }
        .timeline .time-show {
            margin-bottom: 30px;
            margin-top: 30px;
            position: relative;
        }
        .timeline .timeline-box {
            background: #fff;
            display: block;
            margin: 15px 0;
            position: relative;
            padding: 20px;
        }
        .timeline .timeline-album {
            margin-top: 12px;
        }
        .timeline .timeline-album a {
            display: inline-block;
            margin-right: 5px;
        }
        .timeline .timeline-album img {
            height: 36px;
            width: auto;
            border-radius: 3px;
        }
        @media (min-width: 768px) {
            .timeline .time-show {
                margin-right: -69px;
                text-align: right;
            }
            .timeline .timeline-box {
                margin-left: 45px;
            }
            .timeline .timeline-icon {
                background: #dee2e6;
                border-radius: 50%;
                display: block;
                height: 20px;
                left: -54px;
                margin-top: -10px;
                position: absolute;
                text-align: center;
                top: 50%;
                width: 20px;
            }
            .timeline .timeline-icon i {
                color: #98a6ad;
                font-size: 13px;
                position: absolute;
                left: 4px;
            }
            .timeline .timeline-desk {
                display: table-cell;
                vertical-align: top;
                width: 50%;
            }
            .timeline-item {
                display: table-row;
            }
            .timeline-item:before {
                content: "";
                display: block;
                width: 50%;
            }
            .timeline-item .timeline-desk .arrow {
                border-bottom: 12px solid transparent;
                border-right: 12px solid #fff !important;
                border-top: 12px solid transparent;
                display: block;
                height: 0;
                left: -12px;
                margin-top: -12px;
                position: absolute;
                top: 50%;
                width: 0;
            }
            .timeline-item.timeline-item-left:after {
                content: "";
                display: block;
                width: 50%;
            }
            .timeline-item.timeline-item-left .timeline-desk .arrow-alt {
                border-bottom: 12px solid transparent;
                border-left: 12px solid #fff !important;
                border-top: 12px solid transparent;
                display: block;
                height: 0;
                left: auto;
                margin-top: -12px;
                position: absolute;
                right: -12px;
                top: 50%;
                width: 0;
            }
            .timeline-item.timeline-item-left .timeline-desk .album {
                float: right;
                margin-top: 20px;
            }
            .timeline-item.timeline-item-left .timeline-desk .album a {
                float: right;
                margin-left: 5px;
            }
            .timeline-item.timeline-item-left .timeline-icon {
                left: auto;
                right: -56px;
            }
            .timeline-item.timeline-item-left:before {
                display: none;
            }
            .timeline-item.timeline-item-left .timeline-box {
                margin-right: 45px;
                margin-left: 0;
                text-align: right;
            }
        }
        @media (max-width: 767.98px) {
            .timeline .time-show {
                text-align: center;
                position: relative;
            }
            .timeline .timeline-icon {
                display: none;
            }
        }
        .timeline-sm {
            padding-left: 110px;
        }
        .timeline-sm .timeline-sm-item {
            position: relative;
            padding-bottom: 20px;
            padding-left: 40px;
            border-left: 2px solid #dee2e6;
        }
        .timeline-sm .timeline-sm-item:after {
            content: "";
            display: block;
            position: absolute;
            top: 3px;
            left: -7px;
            width: 12px;
            height: 12px;
            border-radius: 50%;
            background: #fff;
            border: 2px solid #1abc9c;
        }
        .timeline-sm .timeline-sm-item .timeline-sm-date {
            position: absolute;
            left: -104px;
        }
        @media (max-width: 420px) {
            .timeline-sm {
                padding-left: 0;
            }
            .timeline-sm .timeline-sm-date {
                position: relative !important;
                display: block;
                left: 0 !important;
                margin-bottom: 10px;
            }
        }
        /* Additional Styling */
        .container {
            width: 80%;
            margin: 0 auto;
        }
        .social-list-item {
            height: 2rem;
            width: 2rem;
            line-height: calc(2rem - 4px);
            display: block;
            border: 2px solid #adb5bd;
            border-radius: 50%;
            color: #adb5bd;
            margin-right: 10px;
        }
        .text-center {
            text-align: center;
        }
    </style>
</head>
<body>
    <div class="container">
        <!-- Card Section -->
        <div class="card-box">
            <h3 class="text-center">Card Box</h3>
            <p>This is a card box with padding and a border. You can add more content here, including images, text, or any other HTML elements.</p>
        </div>
        <!-- Avatar Section -->
        <div class="text-center">
            <img src="https://via.placeholder.com/150" class="avatar-xl rounded-circle" alt="Avatar">
            <p>Avatar Example</p>
        </div>
        <!-- Navigation Pills -->
        <ul class="nav nav-pills mb-4">
            <li class="nav-item">
                <a class="nav-link active" href="#">Home</a>
            </li>
            <li class="nav-item">
                <a class="nav-link" href="#">Profile</a>
            </li>
            <li class="nav-item">
                <a class="nav-link" href="#">Messages</a>
            </li>
        </ul>
        <!-- Timeline Section -->
        <div class="timeline">
            <div class="timeline-item">
                <div class="timeline-desk">
                    <div class="timeline-box">
                        <h4>Event 1</h4>
                        <p>This is an example of a timeline item. You can describe events, tasks, or activities here.</p>
                    </div>
                </div>
            </div>
            <div class="timeline-item timeline-item-left">
                <div class="timeline-desk">
                    <div class="timeline-box">
                        <h4>Event 2</h4>
                        <p>This is another event displayed on the left side of the timeline. You can customize the content here as well.</p>
                    </div>
                </div>
            </div>
        </div>
        <!-- Social Media Icons Section -->
        <div class="text-center">
            <h4>Follow Us</h4>
            <a href="#" class="social-list-item"><i class="fab fa-facebook-f"></i></a>
            <a href="#" class="social-list-item"><i class="fab fa-twitter"></i></a>
            <a href="#" class="social-list-item"><i class="fab fa-linkedin-in"></i></a>
        </div>
    </div>
    <!-- Footer Section -->
    <footer class="text-center">
        <p>© 2025 Your Website Name | All rights reserved.</p>
    </footer>
</body>
</html>
How to Use:
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