:root {
    --primary-color: #03d6ddc6;      /* Main blue color */
    --secondary-color: #2ecc71;    /* Green accent */
    --dark-color: #1c2b3a;         /* Dark blue-gray */
    --light-color: #ecf0f1;        /* Light gray */
    --text-color: #333333;         /* Main text color */
    --text-light: #7f8c8d;         /* Lighter text for subtitles */
    --white: #ffffff;
    --error-color: #e74c3c;        /* Red for errors */
    --success-color: #27ae60;      /* Green for success */
    
    /* Spacing system - consistent margins and padding */
    --spacing-xs: 0.5rem;   /* 8px */
    --spacing-sm: 1rem;     /* 16px */
    --spacing-md: 2rem;     /* 32px */
    --spacing-lg: 3rem;     /* 48px */
    --spacing-xl: 4rem;     /* 64px */
    
    /* Typography */
    --font-main: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    --font-heading: 'Georgia', serif;
    
    /* Layout */
    --max-width: 1200px;    /* Maximum content width */
    --border-radius: 8px;   /* Rounded corners */
    
    /* Transitions */
    --transition-speed: 0.3s;
}

* {
    margin: 0;              /* Remove default margins */
    padding: 0;             /* Remove default padding */
    box-sizing: border-box; /* Include padding/border in dimensions */
}

html {
    scroll-behavior: smooth;
}

/* Body styles apply to the entire page */
body {
    font-family: var(--font-main);  
    line-height: 1.6;              
    color: var(--text-color);
    background-color: var(--white);
    overflow-x: hidden;              /* Prevent horizontal scrolling */
}

.container {
    max-width: var(--max-width);
    margin: 0 auto;                  /* Center horizontally */
    padding: 0 var(--spacing-md);
}

.section {
    padding: var(--spacing-xl) 0;
}

.section-alt {
    background-color: var(--light-color);
}

/* Section titles - consistent heading styles */
.section-title {
    font-family: var(--font-heading);
    font-size: 2.5rem;
    text-align: center;
    margin-bottom: var(--spacing-sm);
    color: var(--dark-color);
}

.section-description {
    text-align: center;
    color: var(--text-light);
    margin-bottom: var(--spacing-lg);
    font-size: 1.1rem;
}


/* ============================================
   NAVIGATION BAR
   ============================================ */
#navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background-color: var(--dark-color);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    z-index: 1000;      /* High z-index keeps it above other content */
    transition: all var(--transition-speed) ease;
}
.nav-container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 var(--spacing-md);
    display: flex;              /* Enable flexbox */
    justify-content: space-between;  /* Space between items */
    align-items: center;        /* Vertical centering */
    height: 70px;
}

.nav-brand a {
    color: var(--white);
    text-decoration: none;      /* Remove underline */
    font-size: 1.5rem;
    font-weight: bold;
}

.nav-menu {
    display: flex;
    list-style: none;           /* Remove bullet points */
    gap: var(--spacing-md);     /* Space between menu items */
}

.nav-link {
    color: var(--white);
    text-decoration: none;
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--border-radius);
    transition: background-color var(--transition-speed) ease;
}

.nav-link:hover {
    background-color: var(--primary-color);
}

/* Mobile menu toggle - hidden on desktop */
.nav-toggle {
    display: none;              /* Hidden by default */
    flex-direction: column;
    cursor: pointer;            /* Show pointer cursor on hover */
}

/* Hamburger menu bars */
.nav-toggle .bar {
    width: 25px;
    height: 3px;
    background-color: var(--white);
    margin: 3px 0;
    transition: 0.3s;
}


/* ============================================
   HERO SECTION (Home)
   ============================================ */

.hero {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--dark-color) 100%);
    color: var(--white);
    min-height: 70vh;          /* Reduced from 100vh to 70vh */
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    padding: var(--spacing-md);
    position: relative;
    margin-top: 70px;           /* Account for fixed navbar */
}

.hero-content {
    max-width: 800px;
    animation: fadeInUp 1s ease;  /* CSS animation */
}

.hero-title {
    font-size: 3.5rem;
    margin-bottom: var(--spacing-md);
    font-weight: 700;
}

.hero-subtitle {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-lg);
    opacity: 0.9;
}

.hero-buttons {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
    flex-wrap: wrap;            /* Wrap buttons on small screens */
}

/* Scroll indicator animation */
.scroll-indicator {
    position: absolute;
    bottom: 0px;
    animation: bounce 2s infinite;  /* Infinite bouncing animation */
}

.arrow-down {
    width: 0;
    height: 0;
    /* Create triangle using borders */
    border-left: 10px solid transparent;
    border-right: 10px solid transparent;
    border-top: 10px solid var(--white);
    margin: 10px auto;
}


/* ============================================
   BUTTONS
   ============================================ */

/* Base button styles */
.btn {
    display: inline-block;
    padding: var(--spacing-sm) var(--spacing-md);
    text-decoration: none;
    border-radius: var(--border-radius);
    transition: all var(--transition-speed) ease;
    cursor: pointer;
    border: 2px solid transparent;
    font-size: 1rem;
    font-weight: 600;
    text-align: center;
}

.btn-primary {
    background-color: var(--primary-color);
    color: var(--white);
    border-color: var(--primary-color);
}

.btn-primary:hover {
    background-color: var(--dark-color);  /* Darker shade on hover */
    transform: translateY(-2px); /* Lift effect */
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
}

/* Secondary button - alternative action */
.btn-secondary {
    background-color: transparent;
    color: var(--white);
    border-color: var(--white);
}

.btn-secondary:hover {
    background-color: var(--white);
    color: var(--primary-color);
}

/* Small button variant */
.btn-small {
    padding: var(--spacing-xs) var(--spacing-sm);
    font-size: 0.9rem;
}

/* Outline button style */
.btn-outline {
    background-color: transparent;
    color: var(--primary-color);
    border-color: var(--primary-color);
}

.btn-outline:hover {
    background-color: var(--primary-color);
    color: var(--white);
}


/* ============================================
   ABOUT SECTION
   ============================================ */

.about-content {
    display: flex;
    gap: var(--spacing-lg);
    align-items: center;
    flex-wrap: wrap;            /* Stack on small screens */
}

.about-text {
    flex: 1;                    /* Take up available space */
    min-width: 300px;
}

.about-text p {
    margin-bottom: var(--spacing-md);
    line-height: 1.8;
}

.about-image {
    flex: 0 0 300px;            /* Fixed width */
    position: relative;
}

.about-image img {
    width: 100%;
    border-radius: var(--border-radius);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
}

/* Placeholder for missing images */
.image-placeholder {
    display: none;              /* Hidden by default */
    width: 100%;
    height: 300px;
    background-color: var(--light-color);
    border-radius: var(--border-radius);
    justify-content: center;
    align-items: center;
    text-align: center;
    color: var(--text-light);
    border: 2px dashed var(--text-light);
}


/* ============================================
   SKILLS SECTION
   ============================================ */

.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-md);
}

.skill-card {
    background-color: var(--white);
    padding: var(--spacing-md);
    border-radius: var(--border-radius);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    transition: transform var(--transition-speed) ease;
}

/* Card lifts on hover */
.skill-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
}

.skill-icon {
    font-size: 3rem;
    margin-bottom: var(--spacing-sm);
}

.skill-icon img {
    width: 50px;       /* Set width */
    height: 50px;      /* Set height */
    object-fit: contain; /* Keeps proportions */
}

.skill-card h3 {
    color: var(--dark-color);
    margin-bottom: var(--spacing-sm);
}

.skill-card p {
    color: var(--text-light);
    margin-bottom: var(--spacing-md);
}

.skill-icons-row {
    display: flex;              /* Creates horizontal layout */
    justify-content: center;    /* Centers icons horizontally */
    align-items: center;        /* Centers icons vertically */
    gap: 1rem;                  /* Space between icons */
}

/* Individual skill icon sizing */
.skill-logo {
    width: 50px;               /* Adjust size as needed */
    height: 50px;
    object-fit: contain;       /* Maintains aspect ratio */
}

/* Progress bar for skill levels */
.progress-bar {
    width: 100%;
    height: 8px;
    background-color: var(--light-color);
    border-radius: 10px;
    overflow: hidden;           /* Clip the progress fill */
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    border-radius: 10px;
    width: 0;                   /* Start at 0, will be animated by JavaScript */
    transition: width 1s ease;
}


/* ============================================
   PROJECTS SECTION
   ============================================ */

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
}

.project-card {
    background-color: var(--white);
    border-radius: var(--border-radius);
    overflow: hidden;           /* Clip content to rounded corners */
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    transition: transform var(--transition-speed) ease;
    margin-bottom: var(--spacing-lg);
}

.project-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
}

.project-image {
    height: 300px;
    overflow: hidden;
    position: relative;
}

.project-image img {
    width: 100%;
    height: 100%;
    object-fit: contain;          /* Scale image to cover container */
    transition: transform var(--transition-speed) ease;
}

.project-card:hover .project-image img {
    transform: scale(1.00);     /* Subtle zoom effect */
}

.project-content {
    padding: var(--spacing-md);
}

.project-content h3 {
    color: var(--dark-color);
    margin-bottom: var(--spacing-sm);
}

.project-content p {
    color: var(--text-light);
    margin-bottom: var(--spacing-md);
}

/* Project sections for Hardware/Software */
.project-section {
    margin-top: 1rem;
}

.project-section-title {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--text-color);
    margin-bottom: 0.5rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

/* Software grid layout similar to skills */
.project-software-grid {
    display: flex;
    flex-wrap: wrap;
    gap: 0.2rem;
    margin-bottom: 0.5rem;
}

.software-item {
    display: flex;
    align-items: center;
    gap: 0.2rem;
    background: var(--bg-color);
    padding: 0.5rem 1rem;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.software-item:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.software-logo {
    width: 24px;
    height: 24px;
    object-fit: contain;
}

/* Ensure hardware tags stay the same */
.project-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 1rem;
}

/* Project media grid - video + 3 images in one card */
.project-media-grid {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    border-radius: 10px 10px 0 0;
    overflow: hidden;
    padding: 0.5rem;
}

.project-video-main {
    width: 100%;
    height: 300px;
    background: var(--bg-color);
}

.project-video-player {
    width: 100%;
    height: 100%;
    object-fit: contain;
    display: block;
    background: #000;
}

/* Three images in a row below video */
.project-images-row {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 0.5rem;
}

.project-thumbnail {
    position: relative;
    height: 120px;
    border-radius: 8px;
    overflow: hidden;
    background: var(--bg-color);
    cursor: pointer;
    transition: transform 0.2s ease;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.project-thumbnail:hover {
    transform: scale(1.05);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.project-thumbnail img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.image-placeholder-small {
    width: 100%;
    height: 100%;
    display: none;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    font-size: 0.7rem;
}

@media (min-width: 768px) {
    .project-media-grid {
        gap: 1.5rem;
        padding: 1.5rem;
    }
    
    .project-video-main {
        height: 400px;
    }
    
    .project-images-row {
        gap: 1.5rem;
    }
    
    .project-thumbnail {
        height: 150px;
    }
}

@media (min-width: 1200px) {
    .project-media-grid {
        gap: 2rem;
        padding: 2rem;
    }
    
    .project-video-main {
        height: 500px;
    }
    
    .project-images-row {
        gap: 2rem;
    }
    
    .project-thumbnail {
        height: 180px;
    }
}

@media (max-width: 480px) {
    .project-media-grid {
        gap: 0.5rem;
        padding: 0.5rem;
    }
    
    .project-video-main {
        height: 200px;
    }
    
    .project-images-row {
        grid-template-columns: 1fr;
        gap: 0.5rem;
    }
    
    .project-thumbnail {
        height: 150px;
    }
}

.tag {
    background-color: var(--light-color);
    color: var(--primary-color);
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
}

.project-links {
    display: flex;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
}


/* ============================================
   MEDIA SECTION
   ============================================ */

.media-grid {
    display: grid;
    gap: var(--spacing-lg);
}

.media-item {
    background-color: var(--white);
    padding: var(--spacing-md);
    border-radius: var(--border-radius);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.media-item h3 {
    color: var(--dark-color);
    margin-bottom: var(--spacing-md);
}

/* Image gallery grid */
.image-gallery {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-sm);
}

.gallery-image {
    width: 100%;
    height: 200px;
    object-fit: cover;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: transform var(--transition-speed) ease;
}

.gallery-image:hover {
    transform: scale(1.05);
}

/* Video player styling */
.video-player {
    width: 100%;
    border-radius: var(--border-radius);
}

.video-container {
    position: relative;
    padding-bottom: 56.25%;     /* 16:9 aspect ratio */
    height: 0;
    overflow: hidden;
}

.video-container iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    border-radius: var(--border-radius);
}

.media-caption {
    margin-top: var(--spacing-sm);
    color: var(--text-light);
    font-size: 0.9rem;
    text-align: center;
}

/* ============================================
   CONTACT SECTION
   ============================================ */

.contact-content {
    display: flex;
    justify-content: center;
    justify-content: center; /* Centers horizontally */
    align-items: center;     /* Centers vertically */
    max-width: 600px;        /* Optional: constrains width */
    max-height: 400px;        /* Optional: constrains height */
    margin: 0 auto; 
}

/* Contact information cards */
.contact-info {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.contact-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-md);
    background-color: var(--white);
    border-radius: var(--border-radius);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.contact-icon {
    font-size: 1.5rem;
    color: var(--primary-color);
    width: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.mail-logo,
.linkedin-logo,
.github-logo {
    width: 32px;
    height: 32px;
    object-fit: contain;
}

.contact-item h4 {
    color: var(--dark-color);
    margin-bottom: 4px;
}

.contact-item a {
    color: var(--primary-color);
    text-decoration: none;
}

.contact-item a:hover {
    text-decoration: underline;
}

/* Contact form styling */
.contact-form-wrapper {
    background-color: var(--white);
    padding: var(--spacing-md);
    border-radius: var(--border-radius);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.form-group {
    margin-bottom: var(--spacing-md);
}

.form-group label {
    display: block;
    margin-bottom: var(--spacing-xs);
    color: var(--dark-color);
    font-weight: 600;
}

/* Input field styling */
.form-group input,
.form-group textarea {
    width: 100%;
    padding: var(--spacing-sm);
    border: 2px solid var(--light-color);
    border-radius: var(--border-radius);
    font-family: var(--font-main);
    font-size: 1rem;
    transition: border-color var(--transition-speed) ease;
}

/* Focus state - when user clicks in the input */
.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
}

/* Form message display */
.form-message {
    margin-top: var(--spacing-md);
    padding: var(--spacing-sm);
    border-radius: var(--border-radius);
    text-align: center;
    display: none;              /* Hidden by default */
}

.form-message.success {
    background-color: var(--success-color);
    color: var(--white);
    display: block;
}

.form-message.error {
    background-color: var(--error-color);
    color: var(--white);
    display: block;
}


/* ============================================
   FOOTER
   ============================================ */

.footer {
    background-color: var(--dark-color);
    color: var(--white);
    padding: var(--spacing-md) 0;
    text-align: center;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--spacing-md);
}

.social-links {
    display: flex;
    gap: var(--spacing-md);
}

.social-links a {
    color: var(--white);
    text-decoration: none;
    transition: color var(--transition-speed) ease;
}

.social-links a:hover {
    color: var(--primary-color);
}


/* ============================================
   SCROLL TO TOP BUTTON
   ============================================ */

.scroll-top-btn {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background-color: var(--primary-color);
    color: var(--white);
    border: none;
    border-radius: 50%;         /* Make it circular */
    font-size: 1.5rem;
    cursor: pointer;
    display: none;              /* Hidden by default */
    justify-content: center;
    align-items: center;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.3);
    transition: all var(--transition-speed) ease;
    z-index: 999;
}

.scroll-top-btn:hover {
    background-color: var(--dark-color);
    transform: translateY(-3px);
}

.scroll-top-btn.visible {
    display: flex;
}


/* ============================================
   ANIMATIONS
   ============================================ */

/* 
  @keyframes defines animations
  Animation progresses from 0% to 100%
*/

/* Fade in and move up animation */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Bouncing animation for scroll indicator */
@keyframes bounce {
    0%, 20%, 50%, 80%, 100% {
        transform: translateY(0);
    }
    40% {
        transform: translateY(-10px);
    }
    60% {
        transform: translateY(-5px);
    }
}


/* ============================================
   RESPONSIVE DESIGN
   Media Queries for different screen sizes
   ============================================ */

/* 
  @media queries apply styles only at certain screen sizes
*/

/* Tablets and smaller (max-width: 992px) */
@media screen and (max-width: 992px) {
    .hero-title {
        font-size: 2.5rem;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .contact-content {
        grid-template-columns: 1fr;  /* Stack on smaller screens */

    }
}

/* Mobile devices (max-width: 768px) */
@media screen and (max-width: 768px) {
    /* Show mobile menu toggle */
    .nav-toggle {
        display: flex;
    }
    
    /* Hide navigation menu by default on mobile */
    .nav-menu {
        position: fixed;
        right: -100%;            /* Hide off-screen */
        top: 70px;
        flex-direction: column;
        background-color: var(--dark-color);
        width: 100%;
        text-align: center;
        transition: right 0.3s ease;
        box-shadow: 0 10px 27px rgba(0, 0, 0, 0.05);
        padding: var(--spacing-md) 0;
    }
    
    /* Show menu when active */
    .nav-menu.active {
        right: 0;
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-subtitle {
        font-size: 1.2rem;
    }
    
    .hero-buttons {
        flex-direction: column;
    }
    
    .about-content {
        flex-direction: column;
    }
    
    .footer-content {
        flex-direction: column;
        text-align: center;
    }
}

/* Small mobile devices (max-width: 480px) */
@media screen and (max-width: 480px) {
    :root {
        --spacing-md: 1rem;
        --spacing-lg: 2rem;
        --spacing-xl: 3rem;
    }
    
    .hero-title {
        font-size: 1.8rem;
    }
    
    .section-title {
        font-size: 1.8rem;
    }
    
    .skills-grid,
    .projects-grid,
    .tools-grid {
        grid-template-columns: 1fr;  /* Single column on very small screens */
    }
}

@media (max-width: 768px) {
    .skills-grid {
        grid-template-columns: 1fr; /* Single column on mobile */
        justify-items: center;       /* Centers grid items */
    }
    
    .skill-card {
        max-width: 400px;
        width: 100%;
    }
}


/* ============================================
   UTILITY CLASSES
   ============================================ */

/* Text alignment */
.text-center {
    text-align: center;
}

.text-left {
    text-align: left;
}

.text-right {
    text-align: right;
}

/* Margin utilities */
.mt-1 { margin-top: var(--spacing-sm); }
.mt-2 { margin-top: var(--spacing-md); }
.mt-3 { margin-top: var(--spacing-lg); }

.mb-1 { margin-bottom: var(--spacing-sm); }
.mb-2 { margin-bottom: var(--spacing-md); }
.mb-3 { margin-bottom: var(--spacing-lg); }

/* Padding utilities */
.p-1 { padding: var(--spacing-sm); }
.p-2 { padding: var(--spacing-md); }
.p-3 { padding: var(--spacing-lg); }

/* Display utilities */
.hidden {
    display: none;
}

.visible {
    display: block;
}