/* ===== CSS Variables ===== */
:root {
    --primary-color: #2563eb;
    --secondary-color: #7c3aed;
    --accent-color: #06b6d4;
    --dark-color: #0f172a;
    --light-color: #f8fafc;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --danger-color: #ef4444;
    --gradient-primary: linear-gradient(135deg, #2563eb 0%, #7c3aed 100%);
    --gradient-secondary: linear-gradient(135deg, #06b6d4 0%, #2563eb 100%);
    --gradient-dark: linear-gradient(135deg, #0f172a 0%, #1e293b 100%);
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    --transition-fast: all 0.2s ease;
    --transition-base: all 0.3s ease;
    --transition-slow: all 0.5s ease;
    --font-main: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-mono: 'JetBrains Mono', 'Courier New', monospace;
}

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-main);
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--light-color);
    overflow-x: hidden;
}

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

/* ===== Typography ===== */
h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 1rem;
}

h1 { font-size: 3.5rem; }
h2 { font-size: 2.5rem; }
h3 { font-size: 2rem; }
h4 { font-size: 1.5rem; }
h5 { font-size: 1.25rem; }
h6 { font-size: 1rem; }

p {
    margin-bottom: 1rem;
    color: var(--text-secondary);
}

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

a:hover {
    color: var(--secondary-color);
}

/* ===== Loader ===== */
.loader {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--light-color);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 9999;
    transition: opacity 0.5s ease, visibility 0.5s ease;
}

.loader.fade-out {
    opacity: 0;
    visibility: hidden;
}

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

.loader-spinner {
    width: 60px;
    height: 60px;
    border: 4px solid rgba(37, 99, 235, 0.2);
    border-top-color: var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* ===== Navigation ===== */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(248, 250, 252, 0.9);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    z-index: 1000;
    transition: var(--transition-base);
    border-bottom: 1px solid rgba(0, 0, 0, 0.05);
}

.navbar.scrolled {
    background: rgba(248, 250, 252, 0.95);
    box-shadow: var(--shadow-md);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.nav-logo {
    font-size: 1.5rem;
    font-weight: 800;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    display: flex;
    align-items: center;
    gap: 10px;
}

.nav-logo i {
    font-size: 1.8rem;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 30px;
    align-items: center;
}

.nav-link {
    color: var(--text-primary);
    font-weight: 500;
    position: relative;
    padding: 5px 0;
    transition: var(--transition-fast);
}

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

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

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

.theme-toggle {
    background: none;
    border: none;
    font-size: 1.2rem;
    color: var(--text-primary);
    cursor: pointer;
    padding: 8px;
    border-radius: 8px;
    transition: var(--transition-fast);
}

.theme-toggle:hover {
    background: rgba(0, 0, 0, 0.05);
}

.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
    padding: 5px;
}

.bar {
    width: 25px;
    height: 3px;
    background-color: var(--text-primary);
    margin: 3px 0;
    transition: var(--transition-fast);
    border-radius: 3px;
}

/* ===== Hero Section ===== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    position: relative;
    background: var(--light-color);
    overflow: hidden;
    padding-top: 70px;
}

.hero-bg {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    opacity: 0.05;
    z-index: 0;
}

.hero-particles {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}

.hero-container {
    position: relative;
    z-index: 1;
    width: 100%;
}

.hero-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.hero-text {
    animation: fadeInUp 0.8s ease;
}

.hero-subtitle {
    color: var(--primary-color);
    font-size: 1.1rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 2px;
    margin-bottom: 20px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.hero-subtitle::before,
.hero-subtitle::after {
    content: '';
    height: 1px;
    width: 30px;
    background: var(--primary-color);
}

.hero-title {
    font-size: 4rem;
    font-weight: 800;
    margin-bottom: 20px;
    line-height: 1.1;
}

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

.hero-description {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: 30px;
    line-height: 1.7;
}

.hero-buttons {
    display: flex;
    gap: 20px;
    flex-wrap: wrap;
    margin-bottom: 40px;
}

.btn {
    padding: 14px 28px;
    border-radius: 12px;
    font-weight: 600;
    transition: var(--transition-base);
    display: inline-flex;
    align-items: center;
    gap: 10px;
    border: none;
    cursor: pointer;
    font-size: 1rem;
    position: relative;
    overflow: hidden;
}

.btn-primary {
    background: var(--gradient-primary);
    color: white;
    box-shadow: 0 4px 14px rgba(37, 99, 235, 0.25);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(37, 99, 235, 0.35);
}

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

.btn-secondary:hover {
    background: var(--primary-color);
    color: white;
    transform: translateY(-2px);
}

.hero-stats {
    display: flex;
    gap: 40px;
}

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

.stat-number {
    font-size: 2.5rem;
    font-weight: 800;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.stat-label {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.hero-visual {
    position: relative;
    animation: fadeInUp 0.8s ease 0.2s both;
}

.hero-image-wrapper {
    position: relative;
    width: 100%;
    max-width: 500px;
    margin: 0 auto;
}

.hero-image {
    width: 100%;
    height: auto;
    border-radius: 20px;
    box-shadow: var(--shadow-xl);
}

.floating-card {
    position: absolute;
    background: white;
    border-radius: 12px;
    padding: 20px;
    box-shadow: var(--shadow-lg);
    animation: float 3s ease-in-out infinite;
}

.floating-card-1 {
    top: -20px;
    right: -20px;
    animation-delay: 0s;
}

.floating-card-2 {
    bottom: -20px;
    left: -20px;
    animation-delay: 1.5s;
}

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

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

/* ===== Sections ===== */
section {
    padding: 100px 0;
    position: relative;
}

.section-title {
    font-size: 3rem;
    font-weight: 800;
    text-align: center;
    margin-bottom: 20px;
    position: relative;
}

.section-subtitle {
    text-align: center;
    color: var(--text-secondary);
    font-size: 1.1rem;
    margin-bottom: 60px;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

/* ===== About Section ===== */
.about {
    background: white;
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.about-image {
    position: relative;
}

.about-image img {
    width: 100%;
    max-width: 600px;
    border-radius: 20px;
    box-shadow: var(--shadow-xl);
}

.about-decoration {
    position: absolute;
    width: 100%;
    height: 100%;
    border: 3px solid var(--primary-color);
    border-radius: 20px;
    top: 20px;
    left: 20px;
    z-index: -1;
}

.about-text h3 {
    font-size: 2rem;
    margin-bottom: 20px;
}

.about-text p {
    font-size: 1.1rem;
    line-height: 1.8;
    margin-bottom: 30px;
}

.about-features {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
    margin-bottom: 30px;
}

.feature-item {
    display: flex;
    align-items: center;
    gap: 15px;
}

.feature-icon {
    width: 50px;
    height: 50px;
    background: rgba(37, 99, 235, 0.1);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary-color);
    font-size: 1.5rem;
}

.feature-text h4 {
    font-size: 1.1rem;
    margin-bottom: 5px;
}

.feature-text p {
    font-size: 0.9rem;
    margin: 0;
}

/* ===== Experience Timeline ===== */
.experience {
    background: var(--light-color);
}

.timeline {
    position: relative;
    max-width: 900px;
    margin: 0 auto;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 50%;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--gradient-primary);
    transform: translateX(-50%);
}

.timeline-item {
    position: relative;
    margin-bottom: 60px;
    opacity: 0;
    transform: translateY(30px);
}

.timeline-item.show {
    opacity: 1;
    transform: translateY(0);
    transition: all 0.6s ease;
}

.timeline-item:nth-child(odd) .timeline-content {
    margin-right: auto;
    margin-left: 0;
}

.timeline-item:nth-child(even) .timeline-content {
    margin-left: auto;
    margin-right: 0;
}

.timeline-marker {
    position: absolute;
    left: 50%;
    top: 30px;
    width: 20px;
    height: 20px;
    background: var(--primary-color);
    border-radius: 50%;
    transform: translateX(-50%);
    border: 4px solid white;
    box-shadow: 0 0 0 4px rgba(37, 99, 235, 0.2);
    z-index: 1;
}

.timeline-content {
    background: white;
    padding: 30px;
    border-radius: 16px;
    box-shadow: var(--shadow-lg);
    width: calc(50% - 40px);
    position: relative;
}

.timeline-content::before {
    content: '';
    position: absolute;
    top: 30px;
    width: 0;
    height: 0;
    border-style: solid;
}

.timeline-item:nth-child(odd) .timeline-content::before {
    right: -15px;
    border-width: 10px 0 10px 15px;
    border-color: transparent transparent transparent white;
}

.timeline-item:nth-child(even) .timeline-content::before {
    left: -15px;
    border-width: 10px 15px 10px 0;
    border-color: transparent white transparent transparent;
}

.timeline-header {
    margin-bottom: 20px;
}

.timeline-header h3 {
    font-size: 1.5rem;
    margin-bottom: 5px;
}

.company {
    color: var(--primary-color);
    font-weight: 600;
    font-size: 1.1rem;
}

.duration {
    color: var(--text-secondary);
    font-size: 0.9rem;
    display: flex;
    align-items: center;
    gap: 5px;
    margin-top: 5px;
}

.timeline-description {
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 20px;
}

.timeline-tech {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.tech-tag {
    background: rgba(37, 99, 235, 0.1);
    color: var(--primary-color);
    padding: 6px 14px;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 500;
}

/* ===== Skills Section ===== */
.skills {
    background: white;
}

.skills-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 40px;
}

.skill-category {
    background: var(--light-color);
    padding: 40px;
    border-radius: 20px;
    border: 1px solid rgba(0, 0, 0, 0.05);
    transition: var(--transition-base);
}

.skill-category:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.skill-category h3 {
    font-size: 1.5rem;
    margin-bottom: 25px;
    display: flex;
    align-items: center;
    gap: 15px;
}

.skill-category h3 i {
    font-size: 2rem;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.skill-items {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}

.skill-name {
    background: white;
    color: var(--text-primary);
    padding: 10px 20px;
    border-radius: 25px;
    font-weight: 500;
    font-size: 0.95rem;
    border: 2px solid transparent;
    transition: var(--transition-base);
    cursor: default;
}

.skill-name:hover {
    border-color: var(--primary-color);
    color: var(--primary-color);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

/* ===== Education Section ===== */
.education {
    background: var(--light-color);
}

.education-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: 40px;
    margin-bottom: 60px;
}

.education-card {
    background: white;
    padding: 40px;
    border-radius: 20px;
    box-shadow: var(--shadow-lg);
    transition: var(--transition-base);
    position: relative;
    overflow: hidden;
}

.education-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 5px;
    background: var(--gradient-primary);
}

.education-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-xl);
}

.education-icon {
    width: 70px;
    height: 70px;
    background: var(--gradient-primary);
    border-radius: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 2rem;
    margin-bottom: 20px;
}

.education-content h3 {
    font-size: 1.5rem;
    margin-bottom: 10px;
}

.institution {
    color: var(--primary-color);
    font-weight: 600;
    margin-bottom: 10px;
    font-size: 1.1rem;
}

.year {
    color: var(--text-secondary);
    font-size: 0.95rem;
    margin-bottom: 15px;
    display: flex;
    align-items: center;
    gap: 5px;
}

.year i {
    font-size: 0.9rem;
}

.coursework {
    margin-top: 25px;
    padding-top: 25px;
    border-top: 1px solid rgba(0, 0, 0, 0.1);
}

.coursework h4 {
    color: var(--text-primary);
    margin-bottom: 15px;
    font-size: 1.1rem;
    font-weight: 600;
}

.course-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.course-tag {
    background: rgba(37, 99, 235, 0.1);
    color: var(--primary-color);
    padding: 6px 14px;
    border-radius: 15px;
    font-size: 0.85rem;
    font-weight: 500;
}

/* ===== Certifications Section ===== */
.certifications {
    margin-top: 60px;
}

.certifications h3 {
    font-size: 1.8rem;
    margin-bottom: 40px;
    color: var(--text-primary);
    text-align: center;
}

.cert-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 25px;
    max-width: 1200px;
    margin: 0 auto;
}

.cert-card {
    background: linear-gradient(135deg, #ffffff 0%, #f8fafc 100%);
    padding: 25px;
    border-radius: 16px;
    box-shadow: var(--shadow-md);
    transition: var(--transition-base);
    position: relative;
    overflow: hidden;
    border: 1px solid rgba(37, 99, 235, 0.1);
}

.cert-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background: var(--gradient-primary);
}

.cert-card:hover {
    transform: translateY(-3px) scale(1.02);
    box-shadow: var(--shadow-lg);
    border-color: rgba(37, 99, 235, 0.3);
}

.cert-icon {
    width: 50px;
    height: 50px;
    background: var(--gradient-secondary);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.3rem;
    margin-bottom: 15px;
    position: relative;
}

.cert-icon::after {
    content: '';
    position: absolute;
    top: -2px;
    left: -2px;
    right: -2px;
    bottom: -2px;
    background: var(--gradient-secondary);
    border-radius: 14px;
    z-index: -1;
    opacity: 0.3;
    transition: var(--transition-base);
}

.cert-card:hover .cert-icon::after {
    opacity: 0.6;
    transform: scale(1.1);
}

.cert-content h4 {
    font-size: 1.2rem;
    margin-bottom: 8px;
    color: var(--text-primary);
    font-weight: 700;
}

.cert-provider {
    color: var(--secondary-color);
    font-weight: 600;
    margin-bottom: 4px;
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.cert-year {
    color: var(--text-secondary);
    font-size: 0.85rem;
    margin-bottom: 12px;
    font-weight: 500;
}

.cert-description {
    color: var(--text-secondary);
    line-height: 1.5;
    margin-bottom: 15px;
    font-size: 0.9rem;
}

.cert-topics {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
}

.cert-topic {
    background: linear-gradient(135deg, rgba(37, 99, 235, 0.1) 0%, rgba(124, 58, 237, 0.1) 100%);
    color: var(--primary-color);
    padding: 4px 10px;
    border-radius: 10px;
    font-size: 0.75rem;
    font-weight: 600;
    transition: var(--transition-base);
    border: 1px solid rgba(37, 99, 235, 0.2);
}

.cert-topic:hover {
    background: var(--gradient-primary);
    color: white;
    transform: translateY(-1px);
    box-shadow: var(--shadow-sm);
    border-color: transparent;
}

/* ===== Projects Section ===== */
.projects {
    background: white;
}

.project-filters {
    display: flex;
    justify-content: center;
    gap: 15px;
    margin-bottom: 50px;
    flex-wrap: wrap;
}

.filter-btn {
    padding: 12px 24px;
    border: 2px solid rgba(37, 99, 235, 0.2);
    background: white;
    color: var(--text-primary);
    border-radius: 30px;
    cursor: pointer;
    transition: var(--transition-base);
    font-weight: 500;
    font-size: 0.95rem;
}

.filter-btn.active,
.filter-btn:hover {
    background: var(--gradient-primary);
    color: white;
    border-color: transparent;
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 30px;
}

.project-card {
    background: var(--light-color);
    border-radius: 20px;
    overflow: hidden;
    transition: var(--transition-base);
    cursor: pointer;
    position: relative;
}

.project-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-xl);
}

.project-image {
    height: 250px;
    overflow: hidden;
    position: relative;
}

.project-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s ease;
}

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

.project-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.7);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: opacity 0.3s ease;
}

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

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

.project-content {
    padding: 30px;
}

.project-content h3 {
    font-size: 1.5rem;
    margin-bottom: 15px;
}

.project-content p {
    line-height: 1.6;
    margin-bottom: 20px;
}

.project-tech {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 20px;
}

.project-tech span {
    background: rgba(37, 99, 235, 0.1);
    color: var(--primary-color);
    padding: 5px 12px;
    border-radius: 15px;
    font-size: 0.8rem;
    font-weight: 500;
}

.project-links {
    display: flex;
    gap: 15px;
}

.project-links a {
    color: var(--primary-color);
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 8px;
    transition: var(--transition-fast);
}

.project-links a:hover {
    color: var(--secondary-color);
}

/* ===== Contact Section ===== */
.contact {
    background: var(--gradient-dark);
    color: white;
}

.contact .section-title,
.contact .section-subtitle {
    color: white;
}

.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    max-width: 1000px;
    margin: 0 auto;
}

.contact-info h3 {
    font-size: 2rem;
    margin-bottom: 20px;
}

.contact-info p {
    color: rgba(255, 255, 255, 0.8);
    line-height: 1.7;
    margin-bottom: 30px;
    font-size: 1.1rem;
}

.contact-details {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 20px;
}

.contact-item i {
    width: 50px;
    height: 50px;
    background: rgba(255, 255, 255, 0.1);
    color: white;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.3rem;
}

.contact-item h4 {
    color: white;
    margin-bottom: 5px;
    font-size: 1.1rem;
}

.contact-item a,
.contact-item p {
    color: rgba(255, 255, 255, 0.8);
    font-size: 0.95rem;
}

.contact-item a:hover {
    color: white;
}

.social-links h3 {
    font-size: 2rem;
    margin-bottom: 30px;
}

.social-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
}

.social-link {
    background: rgba(255, 255, 255, 0.1);
    padding: 20px;
    border-radius: 16px;
    display: flex;
    align-items: center;
    gap: 15px;
    color: white;
    transition: var(--transition-base);
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.social-link:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: translateY(-3px);
    border-color: rgba(255, 255, 255, 0.3);
}

.social-link i {
    font-size: 1.5rem;
}

/* ===== Footer ===== */
.footer {
    background: var(--dark-color);
    color: white;
    text-align: center;
    padding: 40px 0;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-content p {
    margin-bottom: 10px;
    color: rgba(255, 255, 255, 0.8);
}

.footer-content p:last-child {
    margin-bottom: 0;
}

/* ===== Back to Top ===== */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: var(--gradient-primary);
    color: white;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    display: none;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    box-shadow: var(--shadow-lg);
    transition: var(--transition-base);
    z-index: 999;
}

.back-to-top:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-xl);
}

.back-to-top.show {
    display: flex;
}

/* ===== Responsive Design ===== */
@media (max-width: 1024px) {
    .hero-content,
    .about-content,
    .contact-content {
        grid-template-columns: 1fr;
        gap: 40px;
    }
    
    .timeline::before {
        left: 30px;
    }
    
    .timeline-item .timeline-content {
        width: calc(100% - 80px);
        margin-left: 80px !important;
    }
    
    .timeline-marker {
        left: 30px;
    }
    
    .timeline-item .timeline-content::before {
        left: -15px !important;
        border-width: 10px 15px 10px 0 !important;
        border-color: transparent white transparent transparent !important;
    }
}

@media (max-width: 768px) {
    h1 { font-size: 2.5rem; }
    h2 { font-size: 2rem; }
    h3 { font-size: 1.5rem; }
    
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background-color: white;
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: var(--shadow-lg);
        padding: 20px 0;
    }
    
    .nav-menu.active {
        left: 0;
    }
    
    .hamburger {
        display: flex;
    }
    
    .hamburger.active .bar:nth-child(1) {
        transform: translateY(8px) rotate(45deg);
    }
    
    .hamburger.active .bar:nth-child(2) {
        opacity: 0;
    }
    
    .hamburger.active .bar:nth-child(3) {
        transform: translateY(-8px) rotate(-45deg);
    }
    
    .hero-title {
        font-size: 3rem;
    }
    
    .hero-stats {
        justify-content: space-around;
    }
    
    .skills-container,
    .education-grid,
    .cert-grid {
        grid-template-columns: 1fr;
        gap: 20px;
    }
    
    .projects-grid {
        grid-template-columns: 1fr;
    }
    
    .social-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2.5rem;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .hero-buttons {
        flex-direction: column;
        width: 100%;
    }
    
    .btn {
        width: 100%;
        justify-content: center;
    }
    
    .cert-grid {
        gap: 15px;
    }
    
    .cert-card {
        padding: 20px;
    }
}

/* ===== Dark Mode ===== */
body.dark-mode {
    --light-color: #0f172a;
    --dark-color: #f8fafc;
    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    background-color: #0f172a;
}

body.dark-mode .navbar {
    background: rgba(15, 23, 42, 0.9);
}

body.dark-mode .navbar.scrolled {
    background: rgba(15, 23, 42, 0.95);
}

body.dark-mode .about,
body.dark-mode .skills,
body.dark-mode .projects {
    background: #1e293b;
}

body.dark-mode .timeline-content,
body.dark-mode .education-card,
body.dark-mode .skill-category,
body.dark-mode .cert-card,
body.dark-mode .project-card {
    background: #1e293b;
}

body.dark-mode .skill-category {
    background: #1e293b;
    border: 1px solid rgba(255, 255, 255, 0.1);
}

body.dark-mode .skill-name {
    background: #334155;
    color: #e2e8f0;
    border-color: rgba(255, 255, 255, 0.1);
}

body.dark-mode .skill-name:hover {
    border-color: #60a5fa;
    color: #60a5fa;
    background: #475569;
}

body.dark-mode .cert-topic {
    background: rgba(37, 99, 235, 0.2);
    color: #60a5fa;
}

body.dark-mode .floating-card {
    background: #1e293b;
}

body.dark-mode .footer {
    background: #0f172a;
    color: white;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

body.dark-mode .footer-content p {
    color: rgba(255, 255, 255, 0.8);
}

/* ===== Animations ===== */
@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes slideInLeft {
    from {
        opacity: 0;
        transform: translateX(-50px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes slideInRight {
    from {
        opacity: 0;
        transform: translateX(50px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes pulse {
    0% { transform: scale(1); }
    50% { transform: scale(1.05); }
    100% { transform: scale(1); }
}

.animate-fadeIn {
    animation: fadeIn 0.8s ease;
}

.animate-slideInLeft {
    animation: slideInLeft 0.8s ease;
}

.animate-slideInRight {
    animation: slideInRight 0.8s ease;
}

.animate-pulse {
    animation: pulse 2s ease-in-out infinite;
}