Step 2: Update Your CSS File for Responsive Design

Now, let's update our CSS to make it responsive:

Responsive Foundation

/* Responsive Foundation */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

/* Use relative units for better scaling */
html {
    font-size: 16px; /* Base font size */
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f5f5f5;
    padding: 1rem; /* Padding using rem for scaling */
}

/* Fluid container for page content */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

/* Responsive Typography */
h1 {
    font-size: 2rem; /* Scales with root font size */
    margin-bottom: 1rem;
}

h2 {
    font-size: 1.75rem;
    margin-bottom: 0.875rem;
}

h3 {
    font-size: 1.5rem;
    margin-bottom: 0.75rem;
}

p, li, figcaption {
    font-size: 1rem;
    margin-bottom: 1rem;
}

/* Make text size slightly larger on large screens */
@media (min-width: 1200px) {
    html {
        font-size: 18px;
    }
}

/* Make text size slightly smaller on very small screens */
@media (max-width: 320px) {
    html {
        font-size: 14px;
    }
}

Responsive Images

/* Responsive Images */
img {
    max-width: 100%; /* Images never exceed their container width */
    height: auto; /* Maintain aspect ratio */
    display: block; /* Remove inline spacing */
}

.profile-image {
    margin: 0 auto 1.5rem;
    text-align: center;
}

.profile-image img {
    width: 200px; /* Default size */
    height: 200px;
    border-radius: 50%;
    object-fit: cover; /* Ensures image fills area without distortion */
    box-shadow: 0 3px 10px rgba(0, 0, 0, 0.2);
}

/* Adjust profile image size on different screens */
@media (max-width: 768px) {
    .profile-image img {
        width: 150px;
        height: 150px;
    }
}

@media (max-width: 480px) {
    .profile-image img {
        width: 120px;
        height: 120px;
    }
}

Responsive Layout with Flexbox and Grid

/* Responsive Header */
header {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    padding: 2rem 1rem;
    margin-bottom: 2rem;
    background-color: #fff;
    border-radius: 10px;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
}

/* On larger screens, header can be more horizontal */
@media (min-width: 768px) {
    header {
        flex-direction: row;
        text-align: left;
        padding: 2rem;
    }
    
    .profile-image {
        margin: 0 2rem 0 0;
    }
    
    .header-text {
        flex: 1;
    }
}

/* Main Content Layout */
main {
    display: grid;
    grid-template-columns: 1fr; /* Single column on mobile */
    gap: 1.5rem;
}

/* Two-column layout on tablets */
@media (min-width: 768px) {
    main {
        grid-template-columns: 1fr 1fr;
        gap: 2rem;
    }
    
    /* Full-width sections */
    #about,
    #contact {
        grid-column: 1 / -1;
    }
}

/* Three-column layout on desktops */
@media (min-width: 1024px) {
    main {
        grid-template-columns: 2fr 1fr 1fr;
    }
    
    #about {
        grid-column: 1 / -1;
    }
    
    #skills {
        grid-column: 1 / 2;
    }
    
    #education,
    #projects {
        grid-column: 2 / 4;
    }
    
    #contact {
        grid-column: 1 / -1;
    }
}

Responsive Navigation

/* Responsive Navigation */
nav ul {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    list-style-type: none;
    padding: 0;
}

nav li {
    margin: 0.5rem;
}

nav a {
    display: block;
    padding: 0.5rem 1rem;
    background-color: #0066cc;
    color: white;
    text-decoration: none;
    border-radius: 5px;
    text-align: center;
    transition: background-color 0.3s;
}

nav a:hover {
    background-color: #004c99;
}

/* Mobile navigation (hamburger menu) */
.mobile-nav-toggle {
    display: none; /* Hidden by default */
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    padding: 0.5rem;
}

/* Show hamburger on small screens */
@media (max-width: 640px) {
    .mobile-nav-toggle {
        display: block;
        position: absolute;
        top: 1rem;
        right: 1rem;
    }
    
    nav ul {
        display: none; /* Hide by default */
        flex-direction: column;
        width: 100%;
    }
    
    nav li {
        margin: 0;
        width: 100%;
    }
    
    nav a {
        border-radius: 0;
        padding: 1rem;
    }
    
    /* When nav is toggled open */
    nav.open ul {
        display: flex;
    }
}

Note: The mobile navigation toggle requires JavaScript to toggle the "open" class. Here's a simple script to add:

// Add this in a script tag at the end of your body or in a separate JS file
document.querySelector('.mobile-nav-toggle').addEventListener('click', function() {
    document.querySelector('nav').classList.toggle('open');
});

Responsive Form Elements

/* Responsive Forms */
form {
    display: grid;
    gap: 1.5rem;
}

/* Single column on mobile */
form div {
    width: 100%;
}

/* Two columns on larger screens */
@media (min-width: 768px) {
    form {
        grid-template-columns: 1fr 1fr;
    }
    
    /* Full-width items */
    .full-width {
        grid-column: 1 / -1;
    }
}

label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: bold;
}

input,
textarea,
select {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid #ddd;
    border-radius: 5px;
    font-family: inherit;
    font-size: 1rem;
}

/* Make form elements larger on touch screens for better usability */
@media (hover: none) {
    input,
    textarea,
    select,
    button {
        padding: 0.875rem;
        font-size: 1rem;
    }
}

button {
    background-color: #0066cc;
    color: white;
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: 5px;
    cursor: pointer;
    font-size: 1rem;
    font-weight: bold;
    transition: background-color 0.3s;
}

button:hover {
    background-color: #004c99;
}

Section Styling

/* Responsive Sections */
section {
    background-color: #fff;
    border-radius: 10px;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
    padding: 1.5rem;
    margin-bottom: 1.5rem;
}

/* More padding on larger screens */
@media (min-width: 768px) {
    section {
        padding: 2rem;
        margin-bottom: 2rem;
    }
}

/* Project cards responsive layout */
.projects-container {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.5rem;
}

@media (min-width: 640px) {
    .projects-container {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (min-width: 1024px) {
    .projects-container {
        grid-template-columns: repeat(3, 1fr);
    }
}

.project-card {
    border: 1px solid #eee;
    border-radius: 8px;
    overflow: hidden;
}

.project-card img {
    width: 100%;
    height: 200px;
    object-fit: cover;
}

.project-info {
    padding: 1rem;
}

/* Skills list with visual indicators */
.skills-list {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1rem;
}

@media (min-width: 480px) {
    .skills-list {
        grid-template-columns: repeat(2, 1fr);
    }
}

.skill-item {
    margin-bottom: 1rem;
}

.skill-name {
    margin-bottom: 0.5rem;
    font-weight: bold;
}

.skill-bar {
    height: 10px;
    background-color: #eee;
    border-radius: 5px;
    overflow: hidden;
}

.skill-level {
    height: 100%;
    background-color: #0066cc;
}

Touch-Friendly Adjustments

/* Touch-Friendly Adjustments */
/* Detect if device supports touch using a media query */
@media (hover: none) {
    /* Increase tap target sizes */
    nav a,
    .project-card a,
    button {
        padding: 0.75rem 1.5rem;
        min-height: 44px; /* Minimum recommended touch target size */
    }
    
    /* Add more space between links */
    nav li {
        margin: 0.75rem;
    }
    
    /* Ensure sufficient spacing in lists */
    li {
        margin-bottom: 0.75rem;
    }
}

Print Styles (Bonus)

/* Print Styles */
@media print {
    body {
        background-color: white;
        color: black;
        font-size: 12pt;
        line-height: 1.4;
    }
    
    .container {
        width: 100%;
        max-width: none;
    }
    
    header, section {
        box-shadow: none;
        border: 1px solid #ddd;
        margin-bottom: 1rem;
        padding: 1rem;
    }
    
    nav, 
    form, 
    .mobile-nav-toggle,
    .project-card a.btn {
        display: none;
    }
    
    a {
        color: black;
        text-decoration: none;
    }
    
    a::after {
        content: " (" attr(href) ")";
        font-size: 90%;
    }
    
    h1, h2, h3 {
        page-break-after: avoid;
    }
    
    img {
        max-width: 100% !important;
    }
    
    @page {
        margin: 1.5cm;
    }
}