/* ============================================================================ */
/* PORTFOLIO WEBSITE STYLESHEET */
/* ============================================================================ */
/* This stylesheet contains all styling for Surya Prakash's professional portfolio */
/* website. It includes responsive design, animations, and modern UI components. */
/*  */
/* File Structure: */
/* 1. CSS Custom Properties (Variables) */
/* 2. Global Styles & Reset */
/* 3. Typography */
/* 4. Layout & Container Styles */
/* 5. Navigation Header Styles */
/* 6. Hero Section Styles */
/* 7. About Section Styles */
/* 8. Skills Section Styles */
/* 9. Projects Section Styles */
/* 10. Education Section Styles */
/* 11. Contact Section Styles */
/* 12. Footer Styles */
/* 13. Animations & Keyframes */
/* 14. Media Queries (Responsive Design) */
/* 15. Utility Classes */
/* ============================================================================ */

/* ============================================================================ */
/* 1. CSS CUSTOM PROPERTIES (VARIABLES) */
/* ============================================================================ */
/* These are the design tokens used throughout the website. */
/* Modify these variables to quickly change the color scheme and spacing system. */

:root {
    /* Primary Colors */
    --color-primary: #4A90E2;
    --color-primary-dark: #2563EB;
    --color-primary-light: #60A5FA;

    /* Secondary Colors */
    --color-secondary: #1E293B;
    --color-secondary-light: #334155;

    /* Accent Colors */
    --color-accent: #F97316;
    --color-accent-light: #FB923C;

    /* Neutral Colors */
    --color-white: #FFFFFF;
    --color-light: #F8FAFC;
    --color-gray-100: #F1F5F9;
    --color-gray-200: #E2E8F0;
    --color-gray-300: #CBD5E1;
    --color-gray-600: #475569;
    --color-dark: #0F172A;

    /* Semantic Colors */
    --color-success: #10B981;
    --color-error: #EF4444;
    --color-warning: #F59E0B;

    /* Background Gradients */
    --gradient-primary: linear-gradient(135deg, #4A90E2, #2563EB);
    --gradient-accent: linear-gradient(135deg, #F97316, #FB923C);

    /* Spacing System (8px base) */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;
    --spacing-2xl: 48px;
    --spacing-3xl: 64px;

    /* Border Radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
    --radius-full: 9999px;

    /* Typography */
    --font-primary: 'Poppins', sans-serif;
    --font-secondary: 'Inter', sans-serif;

    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 2rem;
    --font-size-4xl: 2.5rem;

    --font-weight-light: 300;
    --font-weight-normal: 400;
    --font-weight-medium: 500;
    --font-weight-semibold: 600;
    --font-weight-bold: 700;

    --line-height-tight: 1.2;
    --line-height-normal: 1.5;
    --line-height-relaxed: 1.75;

    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    --shadow-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);

    /* Transitions */
    --transition-fast: 150ms ease-in-out;
    --transition-base: 250ms ease-in-out;
    --transition-slow: 350ms ease-in-out;

    /* Z-index Scale */
    --z-dropdown: 1000;
    --z-sticky: 1020;
    --z-fixed: 1030;
    --z-modal-backdrop: 1040;
    --z-modal: 1050;
}

/* ============================================================================ */
/* 2. GLOBAL STYLES & RESET */
/* ============================================================================ */
/* Browser reset and base styles for all elements */

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

html {
    scroll-behavior: smooth;
    scrollbar-width: thin;
    scrollbar-color: var(--color-gray-300) transparent;
}

/* WebKit browsers scrollbar styling */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: transparent;
}

::-webkit-scrollbar-thumb {
    background: var(--color-gray-300);
    border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb:hover {
    background: var(--color-gray-600);
}

body {
    font-family: var(--font-secondary);
    font-size: var(--font-size-base);
    line-height: var(--line-height-normal);
    color: var(--color-secondary);
    background-color: var(--color-white);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    text-rendering: optimizeLegibility;
}

/* ============================================================================ */
/* 3. TYPOGRAPHY */
/* ============================================================================ */
/* Heading and text styling */

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-primary);
    font-weight: var(--font-weight-semibold);
    line-height: var(--line-height-tight);
    color: var(--color-secondary);
}

h1 {
    font-size: var(--font-size-4xl);
    font-weight: var(--font-weight-bold);
    margin-bottom: var(--spacing-md);
}

h2 {
    font-size: var(--font-size-3xl);
    font-weight: var(--font-weight-bold);
    margin-bottom: var(--spacing-lg);
}

h3 {
    font-size: var(--font-size-2xl);
    margin-bottom: var(--spacing-md);
}

h4 {
    font-size: var(--font-size-xl);
    margin-bottom: var(--spacing-sm);
}

h5 {
    font-size: var(--font-size-lg);
}

h6 {
    font-size: var(--font-size-base);
}

p {
    margin-bottom: var(--spacing-md);
    line-height: var(--line-height-relaxed);
}

p:last-child {
    margin-bottom: 0;
}

a {
    color: var(--color-primary);
    text-decoration: none;
    transition: color var(--transition-fast);
}

a:hover {
    color: var(--color-primary-dark);
}

/* ============================================================================ */
/* 4. LAYOUT & CONTAINER STYLES */
/* ============================================================================ */
/* Main container and layout utilities */

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

section {
    padding: var(--spacing-3xl) var(--spacing-md);
}

/* Section title styling */
.section-title {
    text-align: center;
    font-size: var(--font-size-3xl);
    margin-bottom: var(--spacing-lg);
    color: var(--color-secondary);
}

/* Divider line under section titles */
.section-divider {
    width: 60px;
    height: 4px;
    background: var(--gradient-primary);
    margin: 0 auto var(--spacing-2xl);
    border-radius: var(--radius-full);
}

/* Skip to content link (accessibility) */
.skip-to-content {
    position: absolute;
    top: -40px;
    left: 0;
    background: var(--color-primary);
    color: var(--color-white);
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-md);
    z-index: var(--z-fixed);
}

.skip-to-content:focus {
    top: 0;
}

/* ============================================================================ */
/* 5. NAVIGATION HEADER STYLES */
/* ============================================================================ */
/* Fixed sticky navigation bar with responsive menu */

.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow-md);
    z-index: var(--z-sticky);
    transition: background-color var(--transition-base);
}

.navbar.scrolled {
    background: rgba(255, 255, 255, 0.98);
    box-shadow: var(--shadow-lg);
}

.navbar-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

/* Logo styling */
.navbar-logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: var(--font-size-2xl);
    font-weight: var(--font-weight-bold);
    color: var(--color-secondary);
    cursor: pointer;
}

.logo-icon {
    width: 40px;
    height: 40px;
    background: var(--gradient-primary);
    color: white;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: var(--font-weight-bold);
}

.logo-text {
    display: none;
}

/* Navigation menu styling */
.nav-menu {
    display: flex;
    gap: var(--spacing-xl);
    list-style: none;
}

.nav-link {
    position: relative;
    font-size: var(--font-size-base);
    font-weight: var(--font-weight-medium);
    color: var(--color-secondary);
    transition: color var(--transition-fast);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--gradient-primary);
    transition: width var(--transition-base);
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}

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

/* Hamburger menu (hidden by default, shown on mobile) */
.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
    gap: 5px;
    z-index: var(--z-modal);
}

.hamburger span {
    width: 25px;
    height: 3px;
    background: var(--color-secondary);
    border-radius: var(--radius-full);
    transition: all var(--transition-base);
}

/* Hamburger animation when active */
.hamburger.active span:nth-child(1) {
    transform: rotate(45deg) translate(8px, 8px);
}

.hamburger.active span:nth-child(2) {
    opacity: 0;
}

.hamburger.active span:nth-child(3) {
    transform: rotate(-45deg) translate(7px, -7px);
}

/* Mobile nav menu positioning */
.nav-menu.mobile-active {
    position: absolute;
    top: 70px;
    left: 0;
    right: 0;
    flex-direction: column;
    background: var(--color-white);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-lg);
    gap: var(--spacing-md);
}

/* ============================================================================ */
/* 6. HERO SECTION STYLES */
/* ============================================================================ */
/* Large hero section with headline, CTA buttons, and profile image */

.hero {
    padding-top: 100px;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    background: linear-gradient(135deg, #ffffff 0%, #f8fafc 100%);
    overflow: hidden;
    position: relative;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    right: 0;
    width: 400px;
    height: 400px;
    background: radial-gradient(circle, rgba(74, 144, 226, 0.1) 0%, transparent 70%);
    border-radius: 50%;
    z-index: 0;
}

.hero-container {
    position: relative;
    z-index: 1;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-3xl);
    align-items: center;
}

/* Hero content (text) section */
.hero-content {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
    animation: fadeInUp 0.8s ease-out;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: var(--font-weight-bold);
    line-height: var(--line-height-tight);
    color: var(--color-secondary);
}

.highlight {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* Typing effect styles */
.hero-subtitle {
    font-size: var(--font-size-2xl);
    color: var(--color-gray-600);
    min-height: 60px;
    font-weight: var(--font-weight-medium);
}

.typing-text {
    color: var(--color-primary);
}

.typing-cursor {
    animation: blink 0.7s infinite;
    color: var(--color-primary);
}

.hero-description {
    font-size: var(--font-size-lg);
    color: var(--color-gray-600);
    line-height: var(--line-height-relaxed);
    max-width: 500px;
}

/* CTA Buttons styling */
.hero-buttons {
    display: flex;
    gap: var(--spacing-md);
    margin-top: var(--spacing-md);
}

.btn {
    padding: var(--spacing-md) var(--spacing-xl);
    border: none;
    border-radius: var(--radius-lg);
    font-size: var(--font-size-base);
    font-weight: var(--font-weight-semibold);
    cursor: pointer;
    transition: all var(--transition-base);
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-family: var(--font-secondary);
}

.btn-primary {
    background: var(--gradient-primary);
    color: var(--color-white);
    box-shadow: var(--shadow-md);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-xl);
}

.btn-secondary {
    background: transparent;
    color: var(--color-primary);
    border: 2px solid var(--color-primary);
}

.btn-secondary:hover {
    background: rgba(74, 144, 226, 0.1);
    transform: translateY(-2px);
}

.btn-large {
    padding: var(--spacing-lg) var(--spacing-2xl);
    font-size: var(--font-size-lg);
}

/* Social links in hero */
.hero-social {
    margin-top: var(--spacing-lg);
}

.social-label {
    font-size: var(--font-size-sm);
    color: var(--color-gray-600);
    font-weight: var(--font-weight-medium);
    margin-bottom: var(--spacing-sm);
}

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

.social-icon {
    width: 45px;
    height: 45px;
    border-radius: var(--radius-full);
    background: rgba(74, 144, 226, 0.1);
    color: var(--color-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-base);
}

.social-icon:hover {
    background: var(--color-primary);
    color: var(--color-white);
    transform: translateY(-3px);
}

/* Profile image section */
.hero-image {
    display: flex;
    justify-content: center;
    align-items: center;
    animation: fadeInRight 0.8s ease-out;
}

.image-placeholder {
    position: relative;
    width: 100%;
    max-width: 400px;
    aspect-ratio: 1;
    background: var(--gradient-primary);
    border-radius: var(--radius-xl);
    padding: 4px;
    box-shadow: var(--shadow-2xl);
}

.profile-img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: var(--radius-lg);
    animation: float 3s ease-in-out infinite;
}

/* Scroll indicator */
.scroll-indicator {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    text-align: center;
    color: var(--color-gray-600);
    font-size: var(--font-size-sm);
    animation: bounce 2s infinite;
}

/* ============================================================================ */
/* 7. ABOUT SECTION STYLES */
/* ============================================================================ */
/* About Me section with text content and highlight boxes */

.about {
    background: var(--color-white);
}

.about-content {
    display: grid;
    gap: var(--spacing-2xl);
}

.about-text {
    font-size: var(--font-size-lg);
    line-height: var(--line-height-relaxed);
    color: var(--color-gray-600);
}

/* Highlight boxes */
.about-highlights {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-lg);
    margin-top: var(--spacing-2xl);
}

.highlight-box {
    background: linear-gradient(135deg, #f8fafc 0%, #f1f5f9 100%);
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    border-left: 4px solid var(--color-primary);
    transition: all var(--transition-base);
}

.highlight-box:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.highlight-box h3 {
    font-size: var(--font-size-lg);
    margin-bottom: var(--spacing-sm);
    color: var(--color-primary);
}

.highlight-box p {
    margin-bottom: var(--spacing-sm);
}

.highlight-detail {
    display: block;
    font-size: var(--font-size-sm);
    color: var(--color-gray-600);
    font-weight: var(--font-weight-medium);
}

/* ============================================================================ */
/* 8. SKILLS SECTION STYLES */
/* ============================================================================ */
/* Skills with category grouping and animated progress bars */

.skills {
    background: linear-gradient(135deg, #f8fafc 0%, #f1f5f9 100%);
}

.skills-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-2xl);
}

.skill-category {
    background: var(--color-white);
    padding: var(--spacing-xl);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
}

.category-title {
    font-size: var(--font-size-lg);
    margin-bottom: var(--spacing-lg);
    color: var(--color-primary);
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.skill-item {
    margin-bottom: var(--spacing-lg);
}

.skill-item:last-child {
    margin-bottom: 0;
}

.skill-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-sm);
}

.skill-name {
    font-weight: var(--font-weight-semibold);
    color: var(--color-secondary);
}

.skill-percentage {
    font-size: var(--font-size-sm);
    color: var(--color-primary);
    font-weight: var(--font-weight-bold);
}

.skill-bar {
    width: 100%;
    height: 8px;
    background: var(--color-gray-200);
    border-radius: var(--radius-full);
    overflow: hidden;
}

.skill-progress {
    height: 100%;
    background: var(--gradient-primary);
    border-radius: var(--radius-full);
    transition: width 1s ease-out;
    position: relative;
}

.skill-progress::after {
    content: '';
    position: absolute;
    right: 0;
    top: 0;
    width: 20%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.3));
}

/* ============================================================================ */
/* 9. PROJECTS SECTION STYLES */
/* ============================================================================ */
/* Projects portfolio with cards, filtering, and hover effects */

.projects {
    background: var(--color-white);
}

/* Filter buttons */
.filter-buttons {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
    margin-bottom: var(--spacing-2xl);
    flex-wrap: wrap;
}

.filter-btn {
    padding: var(--spacing-sm) var(--spacing-lg);
    border: 2px solid var(--color-gray-200);
    background: transparent;
    color: var(--color-secondary);
    border-radius: var(--radius-full);
    font-weight: var(--font-weight-semibold);
    cursor: pointer;
    transition: all var(--transition-base);
    font-size: var(--font-size-sm);
}

.filter-btn:hover,
.filter-btn.active {
    background: var(--gradient-primary);
    color: var(--color-white);
    border-color: var(--color-primary);
}

/* Projects grid */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-xl);
}

.project-card {
    background: var(--color-white);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-md);
    transition: all var(--transition-base);
    cursor: pointer;
}

.project-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
}

.project-card.hidden {
    display: none;
}

.project-image {
    position: relative;
    overflow: hidden;
    height: 250px;
    background: var(--color-gray-200);
}

.project-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform var(--transition-base);
}

.project-card:hover .project-image img {
    transform: scale(1.1);
}

/* Project overlay on hover */
.project-overlay {
    position: absolute;
    inset: 0;
    background: rgba(0, 0, 0, 0.7);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: opacity var(--transition-base);
}

.project-card:hover .project-overlay {
    opacity: 1;
}

.project-overlay-content {
    color: var(--color-white);
    text-align: center;
}

.project-overlay-content h3 {
    font-size: var(--font-size-xl);
    margin-bottom: var(--spacing-sm);
}

.project-overlay-content p {
    font-size: var(--font-size-sm);
    margin: 0;
}

/* Project content */
.project-content {
    padding: var(--spacing-lg);
}

.project-title {
    font-size: var(--font-size-lg);
    margin-bottom: var(--spacing-md);
    color: var(--color-secondary);
}

.project-description {
    font-size: var(--font-size-sm);
    color: var(--color-gray-600);
    line-height: var(--line-height-relaxed);
    margin-bottom: var(--spacing-md);
}

/* Technology tags */
.project-tech {
    display: flex;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
    margin-bottom: var(--spacing-md);
}

.tech-tag {
    display: inline-block;
    background: rgba(74, 144, 226, 0.1);
    color: var(--color-primary);
    padding: 4px 12px;
    border-radius: var(--radius-full);
    font-size: var(--font-size-xs);
    font-weight: var(--font-weight-semibold);
}

/* Project links */
.project-links {
    display: flex;
    gap: var(--spacing-md);
}

.project-link {
    font-size: var(--font-size-sm);
    color: var(--color-primary);
    font-weight: var(--font-weight-semibold);
    padding-bottom: 2px;
    border-bottom: 2px solid transparent;
    transition: border-color var(--transition-fast);
}

.project-link:hover {
    border-bottom-color: var(--color-primary);
}

/* ============================================================================ */
/* 10. EDUCATION SECTION STYLES */
/* ============================================================================ */
/* Education timeline and certifications */

.education {
    background: linear-gradient(135deg, #f8fafc 0%, #f1f5f9 100%);
}

.education-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-3xl);
}

.education-column {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xl);
}

.education-subtitle {
    font-size: var(--font-size-xl);
    color: var(--color-primary);
    margin-bottom: var(--spacing-lg);
}

/* Timeline items */
.education-item {
    display: grid;
    grid-template-columns: auto 1fr;
    gap: var(--spacing-lg);
    position: relative;
    padding-left: var(--spacing-xl);
}

.education-marker {
    width: 16px;
    height: 16px;
    background: var(--color-primary);
    border-radius: 50%;
    position: absolute;
    left: 0;
    top: 8px;
    box-shadow: 0 0 0 8px rgba(74, 144, 226, 0.1);
}

.education-content {
    background: var(--color-white);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
}

.education-title {
    font-size: var(--font-size-lg);
    color: var(--color-secondary);
    margin-bottom: var(--spacing-sm);
}

.education-institution {
    color: var(--color-primary);
    font-weight: var(--font-weight-semibold);
    margin-bottom: 4px;
}

.education-period {
    color: var(--color-gray-600);
    font-size: var(--font-size-sm);
    margin-bottom: var(--spacing-md);
}

.education-details {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.cgpa-badge {
    display: inline-block;
    background: rgba(16, 185, 129, 0.1);
    color: var(--color-success);
    padding: 4px 12px;
    border-radius: var(--radius-full);
    font-weight: var(--font-weight-semibold);
    font-size: var(--font-size-xs);
    width: fit-content;
}

.education-description {
    color: var(--color-gray-600);
    font-size: var(--font-size-sm);
    margin: 0;
}

/* Certification items */
.certification-item {
    display: grid;
    grid-template-columns: auto 1fr;
    gap: var(--spacing-md);
    padding: var(--spacing-lg);
    background: var(--color-white);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    align-items: start;
}

.cert-icon {
    font-size: 2rem;
    min-width: 50px;
    text-align: center;
}

.cert-content h4 {
    margin-bottom: 4px;
    color: var(--color-secondary);
}

.cert-content p {
    margin: 0 0 4px 0;
    font-size: var(--font-size-sm);
    color: var(--color-gray-600);
}

.cert-date {
    display: block;
    font-size: var(--font-size-xs);
    color: var(--color-primary);
    font-weight: var(--font-weight-semibold);
}

/* ============================================================================ */
/* 11. CONTACT SECTION STYLES */
/* ============================================================================ */
/* Contact form and information */

.contact {
    background: var(--color-white);
}

.contact-subtitle {
    text-align: center;
    font-size: var(--font-size-lg);
    color: var(--color-gray-600);
    margin-bottom: var(--spacing-2xl);
    max-width: 500px;
    margin-left: auto;
    margin-right: auto;
}

.contact-wrapper {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-3xl);
    margin-bottom: var(--spacing-3xl);
}

/* Contact form styling */
.contact-form {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.form-label {
    font-weight: var(--font-weight-semibold);
    color: var(--color-secondary);
    font-size: var(--font-size-sm);
}

.form-input {
    padding: var(--spacing-md);
    border: 2px solid var(--color-gray-200);
    border-radius: var(--radius-md);
    font-family: var(--font-secondary);
    font-size: var(--font-size-base);
    transition: border-color var(--transition-base);
}

.form-input:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(74, 144, 226, 0.1);
}

.form-input.error {
    border-color: var(--color-error);
}

.form-textarea {
    resize: vertical;
    min-height: 150px;
    font-family: var(--font-secondary);
}

/* Error messages */
.error-message {
    display: none;
    font-size: var(--font-size-sm);
    color: var(--color-error);
    font-weight: var(--font-weight-medium);
}

.error-message.show {
    display: block;
}

/* Form status message */
.form-status {
    margin-top: var(--spacing-md);
    font-weight: var(--font-weight-medium);
    font-size: var(--font-size-sm);
    display: none;
}

.form-status.success {
    display: block;
    color: var(--color-success);
}

.form-status.error {
    display: block;
    color: var(--color-error);
}

/* Contact info cards */
.contact-info {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-lg);
}

.info-card {
    background: linear-gradient(135deg, #f8fafc 0%, #f1f5f9 100%);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    text-align: center;
    transition: all var(--transition-base);
}

.info-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.info-icon {
    font-size: 2rem;
    margin-bottom: var(--spacing-md);
}

.info-card h4 {
    color: var(--color-secondary);
    margin-bottom: var(--spacing-sm);
}

.info-card p,
.info-card a {
    font-size: var(--font-size-sm);
    color: var(--color-gray-600);
    margin: 0;
}

/* Social media buttons in contact section */
.contact-social {
    text-align: center;
    padding-top: var(--spacing-2xl);
    border-top: 1px solid var(--color-gray-200);
}

.contact-social p {
    margin-bottom: var(--spacing-lg);
    color: var(--color-gray-600);
}

.social-links-large {
    display: flex;
    gap: var(--spacing-lg);
    justify-content: center;
}

.social-btn {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md) var(--spacing-lg);
    background: var(--gradient-primary);
    color: var(--color-white);
    border-radius: var(--radius-lg);
    font-weight: var(--font-weight-semibold);
    transition: all var(--transition-base);
}

.social-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

/* ============================================================================ */
/* 12. FOOTER STYLES */
/* ============================================================================ */
/* Footer section */

.footer {
    background: linear-gradient(135deg, #1e293b 0%, #0f172a 100%);
    color: var(--color-white);
    padding: var(--spacing-2xl) var(--spacing-md);
}

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

.footer-content p {
    margin: 0;
    font-size: var(--font-size-sm);
    color: rgba(255, 255, 255, 0.7);
}

.heart {
    color: var(--color-accent);
    animation: heartbeat 1.5s ease-in-out infinite;
}

/* Back to top button */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: var(--gradient-primary);
    color: var(--color-white);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-base);
    z-index: var(--z-fixed);
    box-shadow: var(--shadow-lg);
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
}

/* ============================================================================ */
/* 13. ANIMATIONS & KEYFRAMES */
/* ============================================================================ */
/* CSS animations for page effects */

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeInRight {
    from {
        opacity: 0;
        transform: translateX(30px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(60px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes bounce {
    0%, 100% {
        transform: translateX(-50%) translateY(0);
    }
    50% {
        transform: translateX(-50%) translateY(-10px);
    }
}

@keyframes float {
    0%, 100% {
        transform: translateY(0px);
    }
    50% {
        transform: translateY(-10px);
    }
}

@keyframes blink {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0;
    }
}

@keyframes heartbeat {
    0%, 100% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.2);
    }
}

/* Fade-in animation for sections on scroll */
.fade-in-section {
    opacity: 0;
    transform: translateY(60px);
    animation: slideUp 0.8s ease-out forwards;
}

.fade-in-section.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ============================================================================ */
/* 14. MEDIA QUERIES (RESPONSIVE DESIGN) */
/* ============================================================================ */
/* Mobile-first responsive design approach */

/* Tablet devices (768px and up) */
@media (max-width: 1024px) {
    .skills-grid {
        grid-template-columns: 1fr;
    }

    .projects-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .about-highlights {
        grid-template-columns: 1fr;
    }

    .hero-title {
        font-size: 2.5rem;
    }

    section {
        padding: var(--spacing-2xl) var(--spacing-md);
    }
}

/* Mobile devices (768px and below) */
@media (max-width: 768px) {
    /* Typography adjustments for mobile */
    h1 {
        font-size: var(--font-size-3xl);
    }

    h2 {
        font-size: var(--font-size-2xl);
    }

    .section-title {
        font-size: var(--font-size-2xl);
    }

    /* Navigation adjustments */
    .logo-text {
        display: inline;
        font-size: var(--font-size-lg);
    }

    .nav-menu {
        display: none;
    }

    .hamburger {
        display: flex;
    }

    /* Hero section adjustments */
    .hero-container {
        grid-template-columns: 1fr;
        gap: var(--spacing-xl);
    }

    .hero-title {
        font-size: 2rem;
    }

    .hero-subtitle {
        font-size: var(--font-size-xl);
        min-height: auto;
    }

    .hero-buttons {
        flex-direction: column;
    }

    .hero-image {
        display: none;
    }

    /* Projects grid */
    .projects-grid {
        grid-template-columns: 1fr;
    }

    /* Education grid */
    .education-grid {
        grid-template-columns: 1fr;
    }

    /* Contact wrapper */
    .contact-wrapper {
        grid-template-columns: 1fr;
        gap: var(--spacing-xl);
    }

    .contact-info {
        grid-template-columns: 1fr;
    }

    /* Footer */
    .footer-content {
        justify-content: center;
        text-align: center;
    }

    .back-to-top {
        bottom: 20px;
        right: 20px;
        width: 45px;
        height: 45px;
        font-size: var(--font-size-sm);
    }

    .social-links-large {
        flex-direction: column;
    }

    .social-btn {
        width: 100%;
        justify-content: center;
    }

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

/* Small mobile devices (480px and below) */
@media (max-width: 480px) {
    .container {
        padding: 0 var(--spacing-sm);
    }

    h1 {
        font-size: var(--font-size-2xl);
    }

    h2 {
        font-size: var(--font-size-xl);
    }

    .section-title {
        font-size: var(--font-size-xl);
    }

    .hero-title {
        font-size: 1.5rem;
    }

    .hero-subtitle {
        font-size: var(--font-size-base);
    }

    .hero-description {
        font-size: var(--font-size-base);
    }

    .btn {
        padding: var(--spacing-md) var(--spacing-lg);
        font-size: var(--font-size-sm);
    }

    .btn-large {
        padding: var(--spacing-md) var(--spacing-lg);
        font-size: var(--font-size-base);
    }

    .hero-buttons {
        gap: var(--spacing-sm);
    }

    .filter-buttons {
        gap: var(--spacing-sm);
    }

    .filter-btn {
        padding: 6px 12px;
        font-size: var(--font-size-xs);
    }

    .about-highlights {
        grid-template-columns: 1fr;
        gap: var(--spacing-md);
    }

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

    .navbar-container {
        height: 60px;
    }

    .hero {
        padding-top: 80px;
    }

    section {
        padding: var(--spacing-lg) var(--spacing-md);
    }
}

/* ============================================================================ */
/* 15. UTILITY CLASSES */
/* ============================================================================ */
/* Utility and helper classes */

/* Visibility utilities */
.hidden {
    display: none !important;
}

.visible {
    display: block !important;
}

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

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

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

/* Margin utilities */
.mt-0 { margin-top: 0; }
.mt-sm { margin-top: var(--spacing-sm); }
.mt-md { margin-top: var(--spacing-md); }
.mt-lg { margin-top: var(--spacing-lg); }
.mt-xl { margin-top: var(--spacing-xl); }

.mb-0 { margin-bottom: 0; }
.mb-sm { margin-bottom: var(--spacing-sm); }
.mb-md { margin-bottom: var(--spacing-md); }
.mb-lg { margin-bottom: var(--spacing-lg); }
.mb-xl { margin-bottom: var(--spacing-xl); }

/* Padding utilities */
.p-0 { padding: 0; }
.p-sm { padding: var(--spacing-sm); }
.p-md { padding: var(--spacing-md); }
.p-lg { padding: var(--spacing-lg); }
.p-xl { padding: var(--spacing-xl); }

/* Print styles */
@media print {
    .navbar,
    .footer,
    .back-to-top,
    .scroll-indicator {
        display: none;
    }

    body {
        background: white;
        color: black;
    }

    a {
        color: blue;
    }
}
.certification-item {
    display: flex;
    gap: 16px;
    padding: 14px;
    border-radius: 12px;
    transition: all 0.3s ease;
    background: #ffffff;
    margin-bottom: 12px;
}

.certification-item:hover {
    box-shadow: 0 10px 25px rgba(0,0,0,0.08);
    transform: translateY(-3px);
}

.cert-image {
    width: 80px;
    height: 80px;
    background: #f3f4f6;
    border-radius: 10px;
    overflow: hidden;
    flex-shrink: 0;
    display: flex;
    align-items: center;
    justify-content: center;
}

.cert-image img {
    width: 100%;
    height: 100%;
    object-fit: contain;
}

.cert-content h4 {
    font-size: 1rem;
    margin-bottom: 2px;
}

.cert-content p {
    font-size: 0.85rem;
    color: #6b7280;
}

.cert-date {
    font-size: 0.75rem;
    color: #9ca3af;
    display: block;
    margin-bottom: 6px;
}

.cert-link {
    font-size: 0.85rem;
    font-weight: 500;
    color: #4f46e5;
    text-decoration: none;
}

.cert-link:hover {
    text-decoration: underline;
    color: #4338ca;
}

/* Mobile Responsive */
@media (max-width: 640px) {
    .certification-item {
        flex-direction: column;
        align-items: flex-start;
    }

    .cert-image {
        width: 100%;
        height: 120px;
    }
}