/* Universal Box-Sizing for easier layout */
*, *::before, *::after {
    box-sizing: border-box;
}

/* General Styles */
:root {
    /* Light Theme Colors */
    --background-color-light: #f4f7f6;
    --text-color-light: #333;
    --heading-color-light: #2c3e50;
    --header-bg-light: #2c3e50;
    --header-text-light: white;
    --nav-link-hover-light: #3498db;
    --button-bg-light: #3498db;
    --button-text-light: white;
    --project-item-bg-light: white;
    --project-text-light: #555;
    --contact-form-bg-light: white;
    --input-border-light: #ddd;
    --input-focus-border-light: #3498db;
    --footer-bg-light: #2c3e50;
    --footer-text-light: white;
    --profile-border-light: white;
    --profile-shadow-light: rgba(0,0,0,0.3);
    --home-gradient-start-light: rgba(0,0,0,0.6);
    --home-gradient-end-light: rgba(0,0,0,0.6);
    --skill-item-bg-light: white;
    --skill-shadow-light: rgba(0,0,0,0.1);
}

body[data-theme="light"] {
    background-color: var(--background-color-light);
    color: var(--text-color-light);
}

body[data-theme="dark"] {
    /* Dark Theme Colors */
    --background-color-dark: #1a1a2e; /* Dark background */
    --text-color-dark: #e0e0e0; /* Light text */
    --heading-color-dark: #e0e0e0; /* Light headings */
    --header-bg-dark: #0f0f1a; /* Even darker header */
    --header-text-dark: #e0e0e0;
    --nav-link-hover-dark: #8c7ae6; /* Purple-ish hover */
    --button-bg-dark: #8c7ae6; /* Purple-ish button */
    --button-text-dark: white;
    --project-item-bg-dark: #2a2a4a; /* Darker project card */
    --project-text-dark: #c0c0c0;
    --contact-form-bg-dark: #2a2a4a; /* Darker form background */
    --input-border-dark: #444;
    --input-focus-border-dark: #8c7ae6;
    --footer-bg-dark: #0f0f1a;
    --footer-text-dark: #e0e0e0;
    --profile-border-dark: #8c7ae6; /* Border matches button */
    --profile-shadow-dark: rgba(0,0,0,0.5);
    --home-gradient-start-dark: rgba(0,0,0,0.7);
    --home-gradient-end-dark: rgba(0,0,0,0.7);
    --skill-item-bg-dark: #2a2a4a; /* Darker skill card */
    --skill-shadow-dark: rgba(0,0,0,0.3);
    
    background-color: var(--background-color-dark);
    color: var(--text-color-dark);
}


body {
    font-family: 'Roboto', sans-serif;
    margin: 0;
    padding: 0;
    transition: background-color 0.3s ease, color 0.3s ease; /* Smooth transition */
    font-size: 100%; /* Ensures rem units scale consistently */
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

section {
    padding: 60px 0; /* Increased padding for better spacing */
    scroll-margin-top: 70px; 
    min-height: calc(100vh - 70px);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}

h1, h2, h3 {
    color: var(--heading-color-light); /* Use variable */
    text-align: center;
    margin-bottom: 40px;
    transition: color 0.3s ease; /* Smooth transition */
}

body[data-theme="dark"] h1,
body[data-theme="dark"] h2,
body[data-theme="dark"] h3 {
    color: var(--heading-color-dark); /* Dark theme heading color */
}

a {
    text-decoration: none;
    color: var(--button-bg-light); /* Use button color for links */
}

a:hover {
    color: var(--nav-link-hover-light);
}

body[data-theme="dark"] a {
    color: var(--nav-link-hover-dark);
}

body[data-theme="dark"] a:hover {
    color: var(--nav-link-hover-dark);
}


.button {
    display: inline-block;
    background-color: var(--button-bg-light); /* Use variable */
    color: var(--button-text-light); /* Use variable */
    padding: 12px 25px;
    border-radius: 5px;
    transition: background-color 0.3s ease, transform 0.2s ease, color 0.3s ease; /* Smooth transition */
    text-align: center;
}

.button:hover {
    background-color: var(--nav-link-hover-light); /* Use nav link hover for consistency */
    transform: translateY(-2px);
}

body[data-theme="dark"] .button {
    background-color: var(--button-bg-dark); /* Dark theme button color */
    color: var(--button-text-dark);
}

body[data-theme="dark"] .button:hover {
    background-color: var(--nav-link-hover-dark);
}

/* Header & Navigation */
header {
    background-color: var(--header-bg-light); /* Use variable */
    color: var(--header-text-light); /* Use variable */
    padding: 15px 0;
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
    transition: background-color 0.3s ease, color 0.3s ease; /* Smooth transition */
}

body[data-theme="dark"] header {
    background-color: var(--header-bg-dark); /* Dark theme header */
    color: var(--header-text-dark);
}

header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap; /* Allow wrapping on very small screens */
}

.logo {
    font-size: 1.8em;
    font-weight: 700;
    color: var(--header-text-light);
    flex-shrink: 0;
    transition: color 0.3s ease;
}

body[data-theme="dark"] .logo {
    color: var(--header-text-dark);
}

nav ul {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
    transition: max-height 0.3s ease-out, opacity 0.3s ease-out;
}

nav ul li {
    margin-left: 30px;
}

nav ul li a {
    color: var(--header-text-light);
    font-weight: 400;
    transition: color 0.3s ease;
    padding: 5px 0;
    display: block;
}

nav ul li a:hover,
nav ul li a.active {
    color: var(--nav-link-hover-light);
}

body[data-theme="dark"] nav ul li a {
    color: var(--header-text-dark);
}

body[data-theme="dark"] nav ul li a:hover,
body[data-theme="dark"] nav ul li a.active {
    color: var(--nav-link-hover-dark);
}

.menu-toggle {
    display: none; /* Hidden by default for desktop */
    background: none;
    border: none;
    color: var(--header-text-light);
    font-size: 1.8em;
    cursor: pointer;
    transition: color 0.3s ease;
}

body[data-theme="dark"] .menu-toggle {
    color: var(--header-text-dark);
}

.theme-toggle-button {
    background: none;
    border: none;
    color: var(--header-text-light); /* Icon color */
    font-size: 1.5em;
    cursor: pointer;
    transition: color 0.3s ease, transform 0.2s ease;
}

.theme-toggle-button:hover {
    transform: scale(1.1);
}

body[data-theme="dark"] .theme-toggle-button {
    color: var(--header-text-dark);
}

/* Hero Section (HomePage) */
#home {
    background: linear-gradient(to bottom, var(--home-gradient-start-light), var(--home-gradient-end-light)), url('https://images.unsplash.com/photo-1517694712202-14dd9538aa97?q=80&w=2070&auto=format&fit=crop&ixlib=rb-4.0.3&ixid=M3wxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8fA%3D%3D') no-repeat center center/cover;
    color: var(--header-text-light);
    text-align: center;
    transition: background 0.3s ease, color 0.3s ease;
}

body[data-theme="dark"] #home {
    background: linear-gradient(to bottom, var(--home-gradient-start-dark), var(--home-gradient-end-dark)), url('https://images.unsplash.com/photo-1517694712202-14dd9538aa97?q=80&w=2070&auto=format&fit=crop&ixlib=rb-4.0.3&ixid=M3wxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8fA%3D%3D') no-repeat center center/cover;
    color: var(--text-color-dark);
}

#home .home-layout-container {
    display: flex;
    flex-direction: row;
    flex-wrap: wrap;
    justify-content: center;
    align-items: center;
    width: 100%;
    max-width: 1000px;
    gap: 40px;
    padding: 20px;
}

#home .home-text-content {
    flex: 1;
    min-width: 300px;
    text-align: left;
}

#home .home-image-content {
    flex: 1;
    min-width: 250px;
    display: flex;
    justify-content: center;
    align-items: center;
}

#home h1 {
    font-size: 3.5em;
    margin-bottom: 15px;
    color: var(--header-text-light);
    text-align: left;
}

body[data-theme="dark"] #home h1 {
    color: var(--text-color-dark);
}

#home p {
    font-size: 1.3em;
    max-width: 700px;
    margin-bottom: 30px;
    padding: 0;
    text-align: left;
}

.profile-picture {
    max-width: 270px;
    height: auto;
    width: 100%;
    border-radius: 50%;
    object-fit: cover;
    margin-bottom: 0;
    border: 5px solid var(--profile-border-light);
    box-shadow: 0 0 15px var(--profile-shadow-light);
    transition: border-color 0.3s ease, box-shadow 0.3s ease;
    aspect-ratio: 1 / 1;
}

body[data-theme="dark"] .profile-picture {
    border: 5px solid var(--profile-border-dark);
    box-shadow: 0 0 15px var(--profile-shadow-dark);
}

/* About Page */
#about .content {
    display: flex;
    flex-wrap: wrap;
    gap: 40px;
    align-items: flex-start;
    justify-content: center;
    width: 100%;
}

#about .text-content {
    flex: 2;
    min-width: 300px;
    max-width: 700px;
    text-align: justify;
}

#about .info-list {
    flex: 1;
    min-width: 250px;
}

#about .info-list ul {
    list-style: none;
    padding: 0;
}

#about .info-list ul li {
    margin-bottom: 10px;
}

#about .info-list ul li strong {
    color: var(--button-bg-light);
}

body[data-theme="dark"] #about .info-list ul li strong {
    color: var(--button-bg-dark);
}

/* Skills Section */
#skills .skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 25px;
    width: 100%;
    max-width: 900px;
    justify-content: center;
    margin-top: 20px;
}

.skill-item {
    background-color: var(--skill-item-bg-light);
    padding: 20px 15px;
    border-radius: 8px;
    box-shadow: 0 4px 8px var(--skill-shadow-light);
    text-align: center;
    transition: transform 0.3s ease, box-shadow 0.3s ease, background-color 0.3s ease;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: 80px;
}

.skill-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 6px 12px rgba(0,0,0,0.15);
}

body[data-theme="dark"] .skill-item {
    background-color: var(--skill-item-bg-dark);
    box-shadow: 0 4px 8px var(--skill-shadow-dark);
}

body[data-theme="dark"] .skill-item:hover {
    box-shadow: 0 6px 12px rgba(0,0,0,0.4);
}

.skill-item h3 {
    margin: 0;
    font-size: 1.2em;
    color: var(--heading-color-light);
}

body[data-theme="dark"] .skill-item h3 {
    color: var(--heading-color-dark);
}


/* Projects Page */
#projects .project-gallery {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
    justify-content: center;
    width: 100%;
}

.project-item {
    background-color: var(--project-item-bg-light);
    border-radius: 8px;
    box-shadow: 0 4px 10px rgba(0,0,0,0.1);
    overflow: hidden;
    transition: transform 0.3s ease, box-shadow 0.3s ease, background-color 0.3s ease;
    display: flex;
    flex-direction: column;
}

.project-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 6px 15px rgba(0,0,0,0.15);
}

body[data-theme="dark"] .project-item {
    background-color: var(--project-item-bg-dark);
    box-shadow: 0 4px 10px rgba(0,0,0,0.3);
}

body[data-theme="dark"] .project-item:hover {
    box-shadow: 0 6px 15px rgba(0,0,0,0.4);
}

.project-item img {
    width: 100%;
    aspect-ratio: 16 / 9;
    object-fit: cover;
    display: block;
}

.project-info {
    padding: 20px;
    flex-grow: 1;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
}

.project-info h3 {
    margin-top: 0;
    color: var(--heading-color-light);
    text-align: left;
    margin-bottom: 10px;
}

body[data-theme="dark"] .project-info h3 {
    color: var(--heading-color-dark);
}

.project-info p {
    font-size: 0.95em;
    color: var(--project-text-light);
    margin-bottom: 15px;
}

body[data-theme="dark"] .project-info p {
    color: var(--project-text-dark);
}

.project-info .button {
    align-self: flex-start;
}

/* Contact Page */
#contact .contact-content {
    display: flex;
    justify-content: center;
    gap: 50px;
    flex-wrap: wrap;
    width: 100%;
}

#contact .contact-form {
    background-color: var(--contact-form-bg-light);
    padding: 40px;
    border-radius: 8px;
    box-shadow: 0 4px 10px rgba(0,0,0,0.1);
    transition: background-color 0.3s ease, box-shadow 0.3s ease;
}

body[data-theme="dark"] #contact .contact-form {
    background-color: var(--contact-form-bg-dark);
    box-shadow: 0 4px 10px rgba(0,0,0,0.3);
}

.contact-form label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: var(--text-color-light);
    transition: color 0.3s ease;
}

body[data-theme="dark"] .contact-form label {
    color: var(--text-color-dark);
}

.contact-form input[type="text"],
.contact-form input[type="email"],
.contact-form textarea {
    width: 100%;
    padding: 10px;
    margin-bottom: 20px;
    border: 1px solid var(--input-border-light);
    border-radius: 5px;
    font-size: 1em;
    transition: border-color 0.3s ease, background-color 0.3s ease, color 0.3s ease;
    background-color: white;
    color: #333;
}

body[data-theme="dark"] .contact-form input[type="text"],
body[data-theme="dark"] .contact-form input[type="email"],
body[data-theme="dark"] .contact-form textarea {
    border: 1px solid var(--input-border-dark);
    background-color: #3a3a5a;
    color: var(--text-color-dark);
}

.contact-form input[type="text"]:focus,
.contact-form input[type="email"]:focus,
.contact-form textarea:focus {
    border-color: var(--input-focus-border-light);
    outline: none;
}

body[data-theme="dark"] .contact-form input[type="text"]:focus,
body[data-theme="dark"] .contact-form input[type="email"]:focus,
body[data-theme="dark"] .contact-form textarea:focus {
    border-color: var(--input-focus-border-dark);
}

.contact-form textarea {
    resize: vertical;
    min-height: 120px;
}

.contact-form button {
    width: 100%;
    padding: 15px;
    background-color: #2ecc71;
    color: white;
    border: none;
    border-radius: 5px;
    font-size: 1.1em;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

.contact-form button:hover {
    background-color: #27ae60;
}

.form-message {
    margin-top: 15px;
    padding: 10px;
    border-radius: 5px;
    text-align: center;
    display: none;
    font-size: 0.9em;
}

.form-message.success {
    background-color: #d4edda;
    color: #155724;
    border: 1px solid #c3e6cb;
}

.form-message.error {
    background-color: #f8d7da;
    color: #721c24;
    border: 1px solid #f5c6cb;
}

/* Footer */
footer {
    background-color: var(--footer-bg-light);
    color: var(--footer-text-light);
    text-align: center;
    padding: 20px 0;
    margin-top: 50px;
    transition: background-color 0.3s ease, color 0.3s ease;
}

body[data-theme="dark"] footer {
    background-color: var(--footer-bg-dark);
    color: var(--footer-text-dark);
}

/* Responsive Design with Media Queries */

/* Small devices (phones, 600px and down) */
@media only screen and (max-width: 600px) {
    header .container {
        /* Keep existing flex properties */
        flex-direction: row;
        justify-content: space-between; /* This pushes elements to edges */
        align-items: center;
        padding: 15px 20px;
    }

    /* NEW: Set order for elements in the header */
    .menu-toggle {
        display: block; /* Ensure it's visible on mobile */
        order: 1; /* First item (left-most) */
    }

    .logo {
        order: 2; /* Second item (middle) */
        flex-grow: 1; /* Allows logo to take up available space */
        text-align: center; /* Centers the "VT" text within its expanded space */
        margin: 0; /* Remove any default margins that might interfere */
    }
    
    .theme-toggle-button {
        order: 3; /* Third item (right-most) */
    }

    /* Nav positioning for mobile remains the same (absolute) */
    nav ul {
        flex-direction: column;
        width: 100%;
        max-height: 0;
        overflow: hidden;
        background-color: var(--header-bg-light);
        position: absolute; /* Takes nav out of flex flow */
        top: 60px;
        left: 0;
        box-shadow: 0 2px 5px rgba(0,0,0,0.1);
        padding-bottom: 10px;
        opacity: 0;
    }

    body[data-theme="dark"] nav ul {
        background-color: var(--header-bg-dark);
    }

    nav ul.active {
        max-height: 300px;
        opacity: 1;
    }

    nav ul li {
        margin: 10px 0;
        text-align: center;
    }

    nav ul li a {
        padding: 10px 0;
        font-size: 1.1em;
    }

    #home {
        height: auto;
        padding: 100px 20px 60px 20px;
    }

    #home .home-layout-container {
        flex-direction: column;
        gap: 20px;
    }

    #home .home-text-content {
        text-align: center;
    }

    #home h1 {
        font-size: 2.2em;
        text-align: center;
    }

    #home p {
        font-size: 0.95em;
        margin-bottom: 20px;
        text-align: center;
    }

    .profile-picture {
        max-width: 210px;
        height: auto;
    }

    section {
        padding: 30px 20px;
        scroll-margin-top: 60px; 
    }

    .container {
        padding: 15px;
    }

    h2 {
        font-size: 1.8em;
        margin-bottom: 30px;
    }

    #about .content {
        flex-direction: column;
        align-items: center;
    }

    #about .text-content,
    #about .info-list {
        width: 100%;
        text-align: center;
    }

    #about .info-list ul {
        text-align: left;
        margin-left: 0;
        padding-left: 20px;
    }

    #skills .skills-grid {
        grid-template-columns: repeat(auto-fit, minmax(100px, 1fr)); 
        gap: 15px;
    }

    .skill-item {
        padding: 15px 10px; 
        min-height: 70px;
    }
    
    .skill-item h3 {
        font-size: 1em; 
    }

    #projects .project-gallery {
        grid-template-columns: 1fr;
    }

    .contact-form {
        padding: 25px;
        width: 100%;
    }

    .contact-form input[type="text"],
    .contact-form input[type="email"],
    .contact-form textarea,
    .contact-form button {
        width: 100%;
    }
}

/* NEW MEDIA QUERY for very small phones (e.g., iPhone SE, older Androids) */
@media only screen and (max-width: 400px) {
    #skills .skills-grid {
        grid-template-columns: 1fr;
        gap: 20px;
    }
    .skill-item {
        max-width: 250px;
        margin-left: auto;
        margin-right: auto;
        padding: 12px 10px;
        min-height: 60px;
    }
    
    .skill-item h3 {
        font-size: 0.9em;
    }

    h1 {
        font-size: 2em;
    }
    #home p {
        font-size: 0.9em;
    }
}


/* Medium devices (tablets, 601px to 900px) */
@media only screen and (min-width: 601px) and (max-width: 900px) {
    header .container {
        padding: 15px 30px;
    }

    nav ul li {
        margin-left: 20px;
    }

    #home h1 {
        font-size: 3em;
    }

    #home p {
        font-size: 1.1em;
    }

    section {
        padding: 40px 30px;
    }

    #home .home-layout-container {
        flex-direction: column;
        gap: 30px;
    }

    #home .home-text-content {
        text-align: center;
    }

    #home h1 {
        text-align: center;
    }

    #home p {
        text-align: center;
    }

    #about .content {
        gap: 30px;
    }

    #projects .project-gallery {
        grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
        gap: 20px;
    }

    #skills .skills-grid {
        grid-template-columns: repeat(auto-fit, minmax(130px, 1fr));
        gap: 20px;
    }

    .contact-form {
        max-width: 80%;
    }
}

/* Large devices (desktops, 901px and up) - Base styles are mostly for this */
@media only screen and (min-width: 901px) {
    .container {
        padding: 20px;
    }

    header .container {
        padding: 15px 0;
    }
}

/* Accessibility: Focus styles for keyboard navigation */
a:focus, button:focus, input:focus, textarea:focus {
    outline: 2px solid var(--input-focus-border-light);
    outline-offset: 2px;
}

body[data-theme="dark"] a:focus,
body[data-theme="dark"] button:focus,
body[data-theme="dark"] input:focus,
body[data-theme="dark"] textarea:focus {
    outline: 2px solid var(--input-focus-border-dark);
    outline-offset: 2px;
}