/* ========================================
   Multi-Page Portfolio Website Styles
   Dark Theme for Data Scientist Portfolio
   ======================================== */

/* CSS Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* CSS Variables for Easy Customization */
:root {
    /* Dark Theme Colors */
    --primary-bg: #0a0a0a;
    --secondary-bg: #1a1a1a;
    --card-bg: #1f1f1f;
    --hover-bg: #2a2a2a;
    
    /* Accent Colors */
    --accent-primary: #00d9ff;
    --accent-secondary: #7c3aed;
    --accent-tertiary: #06b6d4;
    --accent-gradient: linear-gradient(135deg, #00d9ff 0%, #7c3aed 100%);
    
    /* Text Colors */
    --text-primary: #ffffff;
    --text-secondary: #e5e5e5;
    --text-muted: #a0a0a0;
    
    /* Other */
    --shadow-sm: 0 2px 8px rgba(0, 217, 255, 0.1);
    --shadow-md: 0 4px 16px rgba(0, 217, 255, 0.15);
    --shadow-lg: 0 8px 32px rgba(0, 217, 255, 0.2);
    --border-radius: 12px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Smooth Scrolling */
html {
    scroll-behavior: smooth;
}

/* Body Styles */
body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', sans-serif;
    line-height: 1.6;
    color: var(--text-secondary);
    background-color: var(--primary-bg);
    overflow-x: hidden;
}

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* ========================================
   Navigation Styles
   ======================================== */

.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(26, 26, 26, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    z-index: 1000;
    transition: var(--transition);
}

.navbar.scrolled {
    box-shadow: var(--shadow-md);
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.2rem 2rem;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    text-decoration: none;
    transition: var(--transition);
}

.logo:hover {
    opacity: 0.8;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 2.5rem;
    align-items: center;
}

.nav-links a {
    text-decoration: none;
    color: var(--text-secondary);
    font-weight: 500;
    font-size: 0.95rem;
    transition: var(--transition);
    position: relative;
    padding: 0.5rem 0;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent-gradient);
    transition: width 0.3s ease;
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--accent-primary);
}

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

/* Hamburger Menu */
.hamburger {
    display: none;
    flex-direction: column;
    gap: 6px;
    cursor: pointer;
    z-index: 1001;
}

.hamburger span {
    width: 28px;
    height: 3px;
    background: var(--text-primary);
    border-radius: 2px;
    transition: var(--transition);
}

.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(8px, -8px);
}

/* ========================================
   Button Styles
   ======================================== */

.btn {
    display: inline-block;
    padding: 0.875rem 2rem;
    text-decoration: none;
    border-radius: 50px;
    font-weight: 600;
    font-size: 0.95rem;
    transition: var(--transition);
    cursor: pointer;
    border: none;
    outline: none;
}

.btn-primary {
    background: var(--accent-gradient);
    color: var(--text-primary);
    box-shadow: var(--shadow-sm);
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
}

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

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

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

.btn-outline:hover {
    background: var(--text-primary);
    color: var(--primary-bg);
    border-color: var(--text-primary);
}

/* ========================================
   Hero Section (Home Page)
   ======================================== */

.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding-top: 80px;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: radial-gradient(circle at 20% 50%, rgba(0, 217, 255, 0.1) 0%, transparent 50%),
                radial-gradient(circle at 80% 80%, rgba(124, 58, 237, 0.1) 0%, transparent 50%);
    pointer-events: none;
}

.hero-wrapper {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
    max-width: 1400px;
}

.hero-content {
    text-align: center;
    position: relative;
    z-index: 1;
    animation: fadeInUp 0.8s ease;
}

.hero-image {
    display: flex;
    justify-content: center;
    align-items: center;
    position: relative;
    z-index: 1;
}

.profile-img {
    width: 400px;
    height: 400px;
    border-radius: 50%;
    object-fit: cover;
    border: 4px solid var(--accent-primary);
    box-shadow: 0 0 40px rgba(0, 217, 255, 0.3), 0 0 80px rgba(124, 58, 237, 0.2);
    transition: var(--transition);
    animation: float 6s ease-in-out infinite;
}

.profile-img:hover {
    transform: scale(1.05);
    box-shadow: 0 0 60px rgba(0, 217, 255, 0.5), 0 0 100px rgba(124, 58, 237, 0.3);
}

@keyframes float {
    0%, 100% {
        transform: translateY(0px);
    }
    50% {
        transform: translateY(-20px);
    }
}

.hero-subtitle {
    font-size: 1.1rem;
    color: var(--accent-primary);
    font-weight: 600;
    margin-bottom: 1rem;
    text-transform: uppercase;
    letter-spacing: 2px;
}

.hero-title {
    font-size: 4rem;
    font-weight: 800;
    color: var(--text-primary);
    margin-bottom: 1.5rem;
    line-height: 1.3;
}

.hero-title br {
    display: block;
    margin-bottom: 0.3rem;
}

.hero-title .highlight {
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    white-space: nowrap;
    display: inline-block;
    min-width: 280px;
    animation: blink-cursor 0.75s step-end infinite;
}

@keyframes blink-cursor {
    from, to {
        border-right-color: transparent;
    }
    50% {
        border-right-color: var(--accent-primary);
    }
}

.hero-description {
    font-size: 1.25rem;
    color: var(--text-muted);
    margin-bottom: 2.5rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.hero-buttons {
    display: flex;
    gap: 1.5rem;
    justify-content: center;
    margin-bottom: 3rem;
    flex-wrap: wrap;
}

.social-links {
    display: flex;
    gap: 1.5rem;
    justify-content: center;
}

.social-links a {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: var(--card-bg);
    color: var(--text-secondary);
    font-size: 1.25rem;
    transition: var(--transition);
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.social-links a:hover {
    background: var(--accent-gradient);
    color: var(--text-primary);
    transform: translateY(-5px);
    box-shadow: var(--shadow-md);
}

/* ========================================
   Section Styles
   ======================================== */

.section {
    padding: 100px 0;
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 1rem;
    text-align: center;
}

.section-subtitle {
    font-size: 1.1rem;
    color: var(--text-muted);
    text-align: center;
    margin-bottom: 4rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

/* ========================================
   About Page Styles
   ======================================== */

.about-image {
    text-align: center;
    margin-bottom: 3rem;
}

.profile-img-large {
    width: 280px;
    height: 280px;
    border-radius: 50%;
    object-fit: cover;
    border: 4px solid var(--accent-primary);
    box-shadow: 0 0 30px rgba(0, 217, 255, 0.3);
    transition: var(--transition);
}

.profile-img-large:hover {
    transform: scale(1.05);
    box-shadow: 0 0 50px rgba(0, 217, 255, 0.5);
}

.about-content {
    display: grid;
    grid-template-columns: 1fr;
    gap: 3rem;
    max-width: 900px;
    margin: 0 auto;
}

.about-text p {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    line-height: 1.8;
}

/* Skills Grid */
.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.skill-card {
    background: var(--card-bg);
    padding: 2rem;
    border-radius: var(--border-radius);
    border: 1px solid rgba(255, 255, 255, 0.05);
    transition: var(--transition);
}

.skill-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-md);
    border-color: var(--accent-primary);
}

.skill-card-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.skill-icon {
    font-size: 2rem;
    color: var(--accent-primary);
}

.skill-card h3 {
    font-size: 1.25rem;
    color: var(--text-primary);
}

.skill-items {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
}

.skill-tag {
    background: var(--secondary-bg);
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: 0.9rem;
    color: var(--text-secondary);
    border: 1px solid rgba(255, 255, 255, 0.1);
    transition: var(--transition);
}

.skill-tag:hover {
    background: var(--accent-gradient);
    color: var(--text-primary);
    border-color: transparent;
}

/* Progress Bars */
.skill-progress {
    margin-bottom: 1.5rem;
}

.skill-progress-header {
    display: flex;
    justify-content: space-between;
    margin-bottom: 0.5rem;
}

.skill-progress-name {
    color: var(--text-secondary);
    font-weight: 500;
}

.skill-progress-percent {
    color: var(--accent-primary);
    font-weight: 600;
}

.skill-progress-bar {
    height: 8px;
    background: var(--secondary-bg);
    border-radius: 4px;
    overflow: hidden;
}

.skill-progress-fill {
    height: 100%;
    background: var(--accent-gradient);
    border-radius: 4px;
    transition: width 1s ease;
}

/* Education Section */
.education-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.education-card {
    background: var(--card-bg);
    padding: 2rem;
    border-radius: var(--border-radius);
    border-left: 4px solid var(--accent-primary);
    transition: var(--transition);
}

.education-card:hover {
    transform: translateX(10px);
    box-shadow: var(--shadow-md);
}

.education-card h3 {
    color: var(--text-primary);
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
}

.education-card .institution {
    color: var(--accent-primary);
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.education-card .period {
    color: var(--text-muted);
    font-size: 0.9rem;
}

/* ========================================
   Projects Page Styles
   ======================================== */

.filter-buttons {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 3rem;
    flex-wrap: wrap;
}

.filter-btn {
    padding: 0.75rem 1.5rem;
    background: var(--card-bg);
    color: var(--text-secondary);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 25px;
    cursor: pointer;
    transition: var(--transition);
    font-weight: 500;
}

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

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 2rem;
}

.project-card {
    background: var(--card-bg);
    border-radius: var(--border-radius);
    overflow: hidden;
    border: 1px solid rgba(255, 255, 255, 0.05);
    transition: var(--transition);
}

.project-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-lg);
    border-color: var(--accent-primary);
}

.project-image {
    width: 100%;
    height: 200px;
    background: linear-gradient(135deg, rgba(0, 217, 255, 0.1) 0%, rgba(124, 58, 237, 0.1) 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 3rem;
    color: var(--accent-primary);
}

.project-content {
    padding: 2rem;
}

.project-card h3 {
    color: var(--text-primary);
    font-size: 1.5rem;
    margin-bottom: 1rem;
}

.project-card p {
    color: var(--text-muted);
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

.project-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
}

.project-tag {
    background: var(--secondary-bg);
    padding: 0.4rem 0.875rem;
    border-radius: 15px;
    font-size: 0.85rem;
    color: var(--text-secondary);
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.project-links {
    display: flex;
    gap: 1rem;
}

.project-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    background: var(--secondary-bg);
    color: var(--accent-primary);
    text-decoration: none;
    border-radius: 8px;
    font-size: 0.9rem;
    transition: var(--transition);
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.project-link:hover {
    background: var(--accent-primary);
    color: var(--text-primary);
}

/* ========================================
   Experience Page Styles
   ======================================== */

.timeline {
    position: relative;
    max-width: 800px;
    margin: 3rem auto;
    padding-left: 3rem;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--accent-gradient);
}

.timeline-item {
    position: relative;
    margin-bottom: 3rem;
    padding-left: 2rem;
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: -3.5rem;
    top: 0;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background: var(--accent-primary);
    border: 3px solid var(--primary-bg);
    box-shadow: 0 0 0 4px var(--secondary-bg);
}

.timeline-content {
    background: var(--card-bg);
    padding: 2rem;
    border-radius: var(--border-radius);
    border: 1px solid rgba(255, 255, 255, 0.05);
    transition: var(--transition);
}

.timeline-content:hover {
    box-shadow: var(--shadow-md);
    border-color: var(--accent-primary);
}

.timeline-date {
    color: var(--accent-primary);
    font-weight: 600;
    margin-bottom: 0.5rem;
    font-size: 0.9rem;
}

.timeline-content h3 {
    color: var(--text-primary);
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
}

.timeline-content .company {
    color: var(--accent-secondary);
    font-weight: 600;
    margin-bottom: 1rem;
}

.timeline-content p {
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 1rem;
}

.timeline-content ul {
    color: var(--text-muted);
    padding-left: 1.5rem;
}

.timeline-content li {
    margin-bottom: 0.5rem;
}

/* Resume Download Section */
.resume-download {
    text-align: center;
    margin-top: 4rem;
    padding: 3rem;
    background: var(--card-bg);
    border-radius: var(--border-radius);
    border: 1px solid rgba(255, 255, 255, 0.05);
}

.resume-download h3 {
    color: var(--text-primary);
    font-size: 1.5rem;
    margin-bottom: 1rem;
}

.resume-download p {
    color: var(--text-muted);
    margin-bottom: 2rem;
}

/* ========================================
   Contact Page Styles
   ======================================== */

.contact-wrapper {
    max-width: 1000px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
}

.contact-form {
    background: var(--card-bg);
    padding: 2.5rem;
    border-radius: var(--border-radius);
    border: 1px solid rgba(255, 255, 255, 0.05);
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
    font-weight: 500;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 0.875rem 1rem;
    background: var(--secondary-bg);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 8px;
    color: var(--text-primary);
    font-family: inherit;
    font-size: 1rem;
    transition: var(--transition);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 3px rgba(0, 217, 255, 0.1);
}

.form-group textarea {
    resize: vertical;
    min-height: 150px;
}

.form-group .error {
    color: #ef4444;
    font-size: 0.875rem;
    margin-top: 0.25rem;
    display: none;
}

.form-group.has-error input,
.form-group.has-error textarea {
    border-color: #ef4444;
}

.form-group.has-error .error {
    display: block;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.contact-info h3 {
    color: var(--text-primary);
    font-size: 1.5rem;
    margin-bottom: 1rem;
}

.contact-info p {
    color: var(--text-muted);
    line-height: 1.6;
}

.contact-methods {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.contact-method {
    display: flex;
    align-items: center;
    gap: 1.5rem;
    padding: 1.5rem;
    background: var(--card-bg);
    border-radius: var(--border-radius);
    border: 1px solid rgba(255, 255, 255, 0.05);
    transition: var(--transition);
}

.contact-method:hover {
    border-color: var(--accent-primary);
    box-shadow: var(--shadow-sm);
}

.contact-method-icon {
    width: 50px;
    height: 50px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--accent-gradient);
    border-radius: 50%;
    font-size: 1.25rem;
    color: var(--text-primary);
}

.contact-method-content h4 {
    color: var(--text-primary);
    margin-bottom: 0.25rem;
}

.contact-method-content a {
    color: var(--accent-primary);
    text-decoration: none;
    transition: var(--transition);
}

.contact-method-content a:hover {
    color: var(--accent-tertiary);
}

/* ========================================
   Footer Styles
   ======================================== */

.footer {
    background: var(--secondary-bg);
    padding: 3rem 0;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
    margin-top: 5rem;
}

.footer-content {
    text-align: center;
}

.footer-social {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
    margin-bottom: 1.5rem;
}

.footer-social a {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: var(--card-bg);
    color: var(--text-secondary);
    transition: var(--transition);
}

.footer-social a:hover {
    background: var(--accent-gradient);
    color: var(--text-primary);
    transform: translateY(-3px);
}

.footer p {
    color: var(--text-muted);
    font-size: 0.9rem;
}

/* ========================================
   Animations
   ======================================== */

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

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

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

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

/* ========================================
   Responsive Design
   ======================================== */

@media (max-width: 992px) {
    .contact-wrapper {
        grid-template-columns: 1fr;
    }
    
    .projects-grid {
        grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    }
}

@media (max-width: 768px) {
    .hamburger {
        display: flex;
    }
    
    .nav-links {
        position: fixed;
        top: 0;
        right: -100%;
        width: 280px;
        height: 100vh;
        background: var(--secondary-bg);
        flex-direction: column;
        padding: 5rem 2rem 2rem;
        gap: 2rem;
        transition: right 0.3s ease;
        box-shadow: var(--shadow-lg);
    }
    
    .nav-links.active {
        right: 0;
    }
    
    .nav-links a {
        font-size: 1.1rem;
    }
    
    .hero-wrapper {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    
    .hero-content {
        text-align: center;
    }
    
    .profile-img {
        width: 280px;
        height: 280px;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-description {
        font-size: 1.1rem;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .skills-grid,
    .education-grid {
        grid-template-columns: 1fr;
    }
    
    .projects-grid {
        grid-template-columns: 1fr;
    }
    
    .timeline {
        padding-left: 2rem;
    }
    
    .timeline-item {
        padding-left: 1.5rem;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 1rem;
    }
    
    .profile-img {
        width: 220px;
        height: 220px;
    }
    
    .profile-img-large {
        width: 200px;
        height: 200px;
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-buttons {
        flex-direction: column;
        width: 100%;
    }
    
    .btn {
        width: 100%;
        text-align: center;
    }
    
    .section-title {
        font-size: 1.75rem;
    }
    
    .filter-buttons {
        gap: 0.5rem;
    }
    
    .filter-btn {
        padding: 0.5rem 1rem;
        font-size: 0.875rem;
    }
}

/* ========================================
   Utility Classes
   ======================================== */

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

.mt-1 { margin-top: 1rem; }
.mt-2 { margin-top: 2rem; }
.mt-3 { margin-top: 3rem; }
.mt-4 { margin-top: 4rem; }

.mb-1 { margin-bottom: 1rem; }
.mb-2 { margin-bottom: 2rem; }
.mb-3 { margin-bottom: 3rem; }
.mb-4 { margin-bottom: 4rem; }

.fade-in {
    animation: fadeIn 0.6s ease;
}

.slide-in-left {
    animation: slideInLeft 0.6s ease;
}

.slide-in-right {
    animation: slideInRight 0.6s ease;
}