/* ======================
   CSS Variables
   ====================== */
:root {
    /* Colors */
    --primary-color: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #818cf8;
    --secondary-color: #8b5cf6;
    --accent-color: #06b6d4;

    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-tertiary: #334155;

    --text-primary: #f8fafc;
    --text-secondary: #cbd5e1;
    --text-muted: #94a3b8;

    --border-color: #334155;
    --shadow-color: rgba(0, 0, 0, 0.3);

    /* Typography */
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-mono: 'Fira Code', 'Courier New', monospace;

    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;

    /* Layout */
    --container-width: 1200px;
    --border-radius: 12px;
    --border-radius-sm: 8px;

    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-primary);
    font-size: 16px;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    overflow-x: hidden;
}

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

ul {
    list-style: none;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

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

.gradient-text {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* ======================
   Navigation
   ====================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(15, 23, 42, 0.9);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
    transition: background var(--transition-normal);
}

.navbar.scrolled {
    background: rgba(15, 23, 42, 0.95);
    box-shadow: 0 4px 20px var(--shadow-color);
}

.nav-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-sm) 0;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-light);
    transition: transform var(--transition-fast);
}

.logo:hover {
    transform: scale(1.05);
}

.nav-links {
    display: flex;
    gap: var(--spacing-lg);
}

.nav-links a {
    color: var(--text-secondary);
    font-weight: 500;
    position: relative;
    padding: 0.5rem 0;
    transition: color var(--transition-fast);
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-color);
    transition: width var(--transition-fast);
}

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

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

.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
}

.mobile-menu-btn span {
    width: 25px;
    height: 3px;
    background: var(--text-primary);
    border-radius: 2px;
    transition: all var(--transition-fast);
}

/* ======================
   Hero Section
   ====================== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    position: relative;
    padding: calc(80px + var(--spacing-xl)) 0 var(--spacing-2xl);
    padding-bottom: var(--spacing-xl);
    overflow: visible;
    z-index: 1;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -20%;
    width: 800px;
    height: 800px;
    background: radial-gradient(circle, rgba(99, 102, 241, 0.15) 0%, transparent 70%);
    border-radius: 50%;
    pointer-events: none;
    animation: float 20s ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: translate(0, 0) scale(1); }
    33% { transform: translate(50px, -50px) scale(1.1); }
    66% { transform: translate(-30px, 30px) scale(0.9); }
}

.hero-content {
    position: relative;
    z-index: 1;
}

.hero-title {
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: var(--spacing-sm);
    animation: fadeInUp 0.8s ease;
}

.hero-subtitle {
    font-size: clamp(1.5rem, 3vw, 2rem);
    font-weight: 500;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
    animation: fadeInUp 0.8s ease 0.2s both;
}

.hero-description {
    font-size: 1.125rem;
    color: var(--text-muted);
    max-width: 700px;
    margin-bottom: var(--spacing-lg);
    line-height: 1.8;
    animation: fadeInUp 0.8s ease 0.4s both;
}

.hero-buttons {
    display: flex;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
    animation: fadeInUp 0.8s ease 0.6s both;
    flex-wrap: wrap;
}

.btn {
    padding: 0.875rem 2rem;
    border-radius: var(--border-radius-sm);
    font-weight: 600;
    font-size: 1rem;
    transition: all var(--transition-fast);
    cursor: pointer;
    border: 2px solid transparent;
    display: inline-block;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: white;
    box-shadow: 0 4px 15px rgba(99, 102, 241, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 25px rgba(99, 102, 241, 0.4);
}

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

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

.hero-social {
    display: flex;
    gap: var(--spacing-md);
    animation: fadeInUp 0.8s ease 0.8s both;
}

.hero-social a {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: var(--bg-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-secondary);
    border: 1px solid var(--border-color);
    transition: all var(--transition-fast);
}

.hero-social a:hover {
    background: var(--primary-color);
    color: white;
    transform: translateY(-3px);
    box-shadow: 0 4px 15px rgba(99, 102, 241, 0.3);
}

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

/* ======================
   Section Styles
   ====================== */
.section {
    padding: var(--spacing-2xl) 0;
    position: relative;
    z-index: 10;
    background: var(--bg-primary);
}

.section-header {
    text-align: center;
    margin-bottom: var(--spacing-xl);
}

.section-title {
    font-size: clamp(2rem, 4vw, 3rem);
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
    position: relative;
    display: inline-block;
}

.section-line {
    width: 80px;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    margin: 0 auto;
    border-radius: 2px;
}

/* ======================
   About Section
   ====================== */
.about-section {
    background: var(--bg-secondary);
    position: relative;
    z-index: 10;
}

.about-content {
    max-width: 900px;
    margin: 0 auto;
}

.about-text {
    font-size: 1.125rem;
    line-height: 1.8;
    color: var(--text-secondary);
}

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

.about-text strong {
    color: var(--primary-light);
    font-weight: 600;
}

/* ======================
   Skills Section
   ====================== */
.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-lg);
    margin-top: var(--spacing-xl);
}

.skill-category {
    background: var(--bg-secondary);
    padding: var(--spacing-lg);
    border-radius: var(--border-radius);
    border: 1px solid var(--border-color);
    transition: all var(--transition-normal);
    position: relative;
    overflow: hidden;
}

.skill-category::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    transform: scaleX(0);
    transform-origin: left;
    transition: transform var(--transition-normal);
}

.skill-category:hover::before {
    transform: scaleX(1);
}

.skill-category:hover {
    transform: translateY(-5px);
    border-color: var(--primary-color);
    box-shadow: 0 10px 30px rgba(99, 102, 241, 0.2);
}

.skill-icon {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-md);
}

.skill-category h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: var(--spacing-md);
    color: var(--text-primary);
}

.skill-list {
    list-style: none;
}

.skill-list li {
    padding: 0.5rem 0;
    color: var(--text-secondary);
    position: relative;
    padding-left: 1.5rem;
}

.skill-list li::before {
    content: '▹';
    position: absolute;
    left: 0;
    color: var(--primary-light);
    font-size: 1.2rem;
}

/* ======================
   Experience Section
   ====================== */
.experience-section {
    background: var(--bg-secondary);
}

.timeline {
    position: relative;
    max-width: 900px;
    margin: 0 auto;
    padding-left: 30px;
}

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

.timeline-item {
    position: relative;
    margin-bottom: var(--spacing-xl);
    padding-left: var(--spacing-lg);
}

.timeline-marker {
    position: absolute;
    left: -7px;
    top: 0;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background: var(--primary-color);
    border: 3px solid var(--bg-secondary);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.2);
    transition: all var(--transition-normal);
}

.timeline-item:hover .timeline-marker {
    transform: scale(1.3);
    box-shadow: 0 0 0 6px rgba(99, 102, 241, 0.3);
}

.timeline-content {
    background: var(--bg-tertiary);
    padding: var(--spacing-lg);
    border-radius: var(--border-radius);
    border: 1px solid var(--border-color);
    transition: all var(--transition-normal);
}

.timeline-item:hover .timeline-content {
    transform: translateX(10px);
    border-color: var(--primary-color);
    box-shadow: 0 5px 20px rgba(99, 102, 241, 0.15);
}

.timeline-date {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    background: rgba(99, 102, 241, 0.1);
    color: var(--primary-light);
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
}

.timeline-content h3 {
    font-size: 1.5rem;
    color: var(--text-primary);
    margin-bottom: 0.25rem;
}

.timeline-content h4 {
    font-size: 1.125rem;
    color: var(--primary-light);
    margin-bottom: var(--spacing-sm);
    font-weight: 600;
}

.timeline-content p {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
    font-style: italic;
}

.timeline-content ul {
    list-style: none;
}

.timeline-content ul li {
    padding: 0.5rem 0;
    padding-left: 1.5rem;
    color: var(--text-secondary);
    position: relative;
    line-height: 1.6;
}

.timeline-content ul li::before {
    content: '▹';
    position: absolute;
    left: 0;
    color: var(--primary-light);
    font-size: 1.2rem;
}

.timeline-content ul li strong {
    color: var(--text-primary);
}

/* ======================
   Projects Section
   ====================== */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: var(--spacing-lg);
    margin-top: var(--spacing-xl);
}

.project-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    padding: var(--spacing-lg);
    transition: all var(--transition-normal);
    position: relative;
    overflow: hidden;
    display: flex;
    flex-direction: column;
}

.project-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    transform: scaleX(0);
    transform-origin: left;
    transition: transform var(--transition-normal);
}

.project-card:hover::before {
    transform: scaleX(1);
}

.project-card:hover {
    transform: translateY(-8px);
    border-color: var(--primary-color);
    box-shadow: 0 15px 40px rgba(99, 102, 241, 0.2);
}

.project-card.featured {
    border-color: var(--primary-color);
    box-shadow: 0 5px 25px rgba(99, 102, 241, 0.15);
}

.featured-badge {
    position: absolute;
    top: 20px;
    right: -30px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    padding: 0.25rem 2.5rem;
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    transform: rotate(45deg);
    box-shadow: 0 2px 10px rgba(99, 102, 241, 0.3);
}

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

.project-header h3 {
    font-size: 1.5rem;
    color: var(--text-primary);
}

.project-link {
    color: var(--text-secondary);
    transition: all var(--transition-fast);
}

.project-link:hover {
    color: var(--primary-light);
    transform: scale(1.1);
}

.project-description {
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: var(--spacing-md);
    flex-grow: 1;
}

.project-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: var(--spacing-md);
}

.tag {
    padding: 0.25rem 0.75rem;
    background: rgba(99, 102, 241, 0.1);
    color: var(--primary-light);
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 500;
}

.project-features {
    margin-top: auto;
    padding-top: var(--spacing-md);
    border-top: 1px solid var(--border-color);
}

.project-features h4 {
    font-size: 1rem;
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
}

.project-features ul {
    list-style: none;
}

.project-features li {
    padding: 0.375rem 0;
    padding-left: 1.25rem;
    color: var(--text-secondary);
    position: relative;
    font-size: 0.9rem;
}

.project-features li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--primary-light);
    font-weight: bold;
}

/* ======================
   Contact Section
   ====================== */
.contact-section {
    background: var(--bg-secondary);
}

.contact-content {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
}

.contact-intro {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-xl);
    line-height: 1.8;
}

.contact-methods {
    display: flex;
    gap: var(--spacing-lg);
    justify-content: center;
    flex-wrap: wrap;
}

.contact-card {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    background: var(--bg-tertiary);
    padding: var(--spacing-lg);
    border-radius: var(--border-radius);
    border: 1px solid var(--border-color);
    transition: all var(--transition-normal);
    min-width: 280px;
}

.contact-card:hover {
    transform: translateY(-5px);
    border-color: var(--primary-color);
    box-shadow: 0 10px 30px rgba(99, 102, 241, 0.2);
}

.contact-card svg {
    color: var(--primary-light);
    transition: transform var(--transition-fast);
}

.contact-card:hover svg {
    transform: scale(1.1);
}

.contact-card h3 {
    font-size: 1.125rem;
    color: var(--text-primary);
    margin-bottom: 0.25rem;
}

.contact-card p {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* ======================
   Footer
   ====================== */
.footer {
    background: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
    padding: var(--spacing-lg) 0;
    text-align: center;
    color: var(--text-muted);
}

/* ======================
   Responsive Design
   ====================== */
@media (max-width: 768px) {
    .mobile-menu-btn {
        display: flex;
    }

    .nav-links {
        position: fixed;
        top: 70px;
        left: 0;
        right: 0;
        background: rgba(15, 23, 42, 0.98);
        backdrop-filter: blur(10px);
        flex-direction: column;
        padding: var(--spacing-lg);
        gap: var(--spacing-md);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: all var(--transition-normal);
        border-bottom: 1px solid var(--border-color);
    }

    .nav-links.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }

    .hero {
        padding: calc(80px + var(--spacing-lg)) 0 var(--spacing-xl);
    }

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

    .btn {
        width: 100%;
        text-align: center;
    }

    .skills-grid {
        grid-template-columns: 1fr;
    }

    .timeline {
        padding-left: 20px;
    }

    .timeline-item {
        padding-left: var(--spacing-md);
    }

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

    .contact-methods {
        flex-direction: column;
    }

    .contact-card {
        width: 100%;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }

    .hero-subtitle {
        font-size: 1.25rem;
    }

    .section-title {
        font-size: 1.75rem;
    }
}

/* ======================
   Animations
   ====================== */
.fade-in {
    animation: fadeIn 1s ease;
}

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

.slide-in-left {
    animation: slideInLeft 0.8s ease;
}

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

.slide-in-right {
    animation: slideInRight 0.8s ease;
}

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

/* Scroll animations */
[data-scroll] {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

[data-scroll].in-view {
    opacity: 1;
    transform: translateY(0);
}

/* Custom scrollbar */
::-webkit-scrollbar {
    width: 12px;
}

::-webkit-scrollbar-track {
    background: var(--bg-primary);
}

::-webkit-scrollbar-thumb {
    background: var(--bg-tertiary);
    border-radius: 6px;
}

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

/* Selection */
::selection {
    background: var(--primary-color);
    color: white;
}