/* ===== CSS Variables ===== */
:root {
    /* Light Mode Colors */
    --bg-primary: #ffffff;
    --bg-secondary: #f8f9fa;
    --bg-tertiary: #e9ecef;
    --text-primary: #1a1a1a;
    --text-secondary: #6c757d;
    --accent-primary: #6366f1;
    --accent-secondary: #8b5cf6;
    --accent-gradient: linear-gradient(135deg, #6366f1 0%, #8b5cf6 100%);
    --card-bg: #ffffff;
    --card-shadow: 0 4px 6px rgba(0, 0, 0, 0.07);
    --card-shadow-hover: 0 20px 40px rgba(0, 0, 0, 0.12);
    --border-color: #e5e7eb;
    --navbar-bg: rgba(255, 255, 255, 0.95);

    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 4rem;
    --spacing-xl: 6rem;

    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-size-xs: 0.875rem;
    --font-size-sm: 1rem;
    --font-size-md: 1.125rem;
    --font-size-lg: 1.5rem;
    --font-size-xl: 2rem;
    --font-size-2xl: 3rem;
    --font-size-3xl: 4rem;

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

/* Dark Mode Variables */
[data-theme="dark"] {
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-tertiary: #334155;
    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --card-bg: #1e293b;
    --card-shadow: 0 4px 6px rgba(0, 0, 0, 0.3);
    --card-shadow-hover: 0 20px 40px rgba(0, 0, 0, 0.4);
    --border-color: #334155;
    --navbar-bg: rgba(15, 23, 42, 0.95);
}

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

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

body {
    font-family: var(--font-family);
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    transition: background-color var(--transition-base), color var(--transition-base);
}

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

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

/* ===== Theme Toggle ===== */
.theme-toggle {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 1001;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    border: none;
    background: var(--accent-gradient);
    color: white;
    font-size: 1.2rem;
    cursor: pointer;
    box-shadow: var(--card-shadow);
    transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.theme-toggle:hover {
    transform: scale(1.1) rotate(15deg);
    box-shadow: var(--card-shadow-hover);
}

/* ===== Navigation ===== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: var(--navbar-bg);
    backdrop-filter: blur(10px);
    box-shadow: var(--card-shadow);
    z-index: 1000;
    transition: all var(--transition-base);
}

.navbar.scrolled {
    padding: 0.5rem 0;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-brand {
    font-size: var(--font-size-lg);
    font-weight: 700;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-link {
    position: relative;
    color: var(--text-primary);
    font-weight: 500;
    padding: 0.5rem 0;
}

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

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

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

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

/* ===== Hero Section ===== */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-xl) var(--spacing-md);
    overflow: hidden;
    background: var(--bg-primary);
}

.hero-particles {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background:
        radial-gradient(circle at 20% 30%, rgba(99, 102, 241, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 70%, rgba(139, 92, 246, 0.1) 0%, transparent 50%);
    animation: float 20s infinite ease-in-out;
}

@keyframes float {
    0%, 100% { transform: translateY(0) rotate(0deg); }
    50% { transform: translateY(-20px) rotate(5deg); }
}

.hero-content {
    position: relative;
    text-align: center;
    max-width: 900px;
    z-index: 1;
    animation: fadeInUp 1s ease;
}

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

.hero-image-wrapper {
    position: relative;
    width: 200px;
    height: 200px;
    margin: 0 auto 2rem;
}

.hero-image-border {
    position: absolute;
    inset: -5px;
    border-radius: 50%;
    background: var(--accent-gradient);
    animation: rotate 10s linear infinite;
}

@keyframes rotate {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

.hero-image {
    position: relative;
    width: 100%;
    height: 100%;
    border-radius: 50%;
    object-fit: cover;
    border: 5px solid var(--bg-primary);
    box-shadow: var(--card-shadow-hover);
}

.hero-title {
    font-size: var(--font-size-3xl);
    font-weight: 800;
    margin-bottom: var(--spacing-sm);
    line-height: 1.1;
}

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

.hero-subtitle {
    font-size: var(--font-size-xl);
    color: var(--text-secondary);
    min-height: 3.5em;
    display: flex;
    align-items: center;
    justify-content: center;
}

.hero-description {
    font-size: var(--font-size-md);
    color: var(--text-secondary);
    max-width: 700px;
    margin: 0 auto var(--spacing-lg);
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
    flex-wrap: wrap;
}

.stat-item {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.stat-number {
    font-size: var(--font-size-2xl);
    font-weight: 700;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.stat-label {
    font-size: var(--font-size-xs);
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 1px;
}

.hero-buttons {
    display: flex;
    gap: var(--spacing-sm);
    justify-content: center;
    margin-bottom: var(--spacing-xl);
    flex-wrap: wrap;
}

.btn {
    padding: 1rem 2rem;
    border-radius: 50px;
    font-weight: 600;
    font-size: var(--font-size-sm);
    cursor: pointer;
    transition: all var(--transition-base);
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    border: none;
}

.btn-primary {
    background: var(--accent-gradient);
    color: white;
    box-shadow: 0 4px 15px rgba(99, 102, 241, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(99, 102, 241, 0.4);
}

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

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

.scroll-indicator {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-secondary);
    font-size: var(--font-size-xs);
    animation: bounce 2s infinite;
}

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

/* ===== Section Styles ===== */
.section {
    padding: var(--spacing-xl) var(--spacing-md);
}

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

.section-title {
    font-size: var(--font-size-2xl);
    font-weight: 700;
    text-align: center;
    margin-bottom: var(--spacing-lg);
    position: relative;
}

.section-title::after {
    content: '';
    display: block;
    width: 100px;
    height: 4px;
    background: var(--accent-gradient);
    margin: 1rem auto 0;
    border-radius: 2px;
}

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

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

.about-intro {
    font-size: var(--font-size-md);
    line-height: 1.8;
    margin-bottom: var(--spacing-lg);
    text-align: center;
}

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

.highlight-item {
    background: var(--card-bg);
    padding: var(--spacing-md);
    border-radius: 20px;
    box-shadow: var(--card-shadow);
    transition: all var(--transition-base);
    text-align: center;
}

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

.highlight-item i {
    font-size: 2.5rem;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: var(--spacing-sm);
}

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

.highlight-item p {
    color: var(--text-secondary);
    font-size: var(--font-size-xs);
}

.philosophy {
    background: var(--card-bg);
    padding: var(--spacing-md);
    border-radius: 20px;
    border-left: 5px solid var(--accent-primary);
    box-shadow: var(--card-shadow);
    text-align: center;
}

.philosophy i {
    font-size: 2rem;
    color: var(--accent-primary);
    margin-bottom: var(--spacing-sm);
}

.philosophy p {
    font-size: var(--font-size-lg);
    font-style: italic;
    margin-bottom: var(--spacing-sm);
}

.philosophy span {
    color: var(--text-secondary);
    font-size: var(--font-size-xs);
}

/* ===== Skills Section ===== */
.skills-section {
    background: var(--bg-primary);
}

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

.skill-category {
    background: var(--card-bg);
    padding: var(--spacing-md);
    border-radius: 20px;
    box-shadow: var(--card-shadow);
    transition: all var(--transition-base);
}

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

.skill-category h3 {
    font-size: var(--font-size-lg);
    margin-bottom: var(--spacing-md);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.skill-category i {
    color: var(--accent-primary);
}

.skill-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.skill-tag {
    background: var(--bg-secondary);
    color: var(--text-primary);
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: var(--font-size-xs);
    font-weight: 500;
    transition: all var(--transition-fast);
    border: 1px solid var(--border-color);
}

.skill-tag:hover {
    background: var(--accent-gradient);
    color: white;
    border-color: transparent;
    transform: translateY(-2px);
}

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

.timeline {
    position: relative;
    padding: 2rem 0;
}

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

.timeline-item {
    position: relative;
    margin-bottom: var(--spacing-lg);
    display: flex;
    align-items: center;
}

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

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

.timeline-marker {
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--accent-gradient);
    border: 4px solid var(--bg-secondary);
    z-index: 1;
    box-shadow: 0 0 0 4px var(--bg-primary);
}

.timeline-content {
    background: var(--card-bg);
    padding: var(--spacing-md);
    border-radius: 20px;
    box-shadow: var(--card-shadow);
    width: calc(50% - 40px);
    transition: all var(--transition-base);
}

.timeline-content:hover {
    transform: scale(1.02);
    box-shadow: var(--card-shadow-hover);
}

.timeline-date {
    display: inline-block;
    font-size: var(--font-size-xs);
    color: white;
    background: var(--accent-gradient);
    padding: 0.25rem 1rem;
    border-radius: 20px;
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
}

.timeline-content h3 {
    font-size: var(--font-size-lg);
    margin-bottom: 0.5rem;
}

.timeline-content h4 {
    color: var(--accent-primary);
    font-size: var(--font-size-md);
    margin-bottom: var(--spacing-sm);
}

.timeline-content p {
    color: var(--text-secondary);
    font-size: var(--font-size-xs);
    line-height: 1.6;
}

/* ===== Projects Section ===== */
.projects-section {
    background: var(--bg-primary);
}

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

.project-card {
    background: var(--card-bg);
    padding: var(--spacing-md);
    border-radius: 20px;
    box-shadow: var(--card-shadow);
    transition: all var(--transition-base);
    border: 1px solid var(--border-color);
}

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

.project-icon {
    width: 60px;
    height: 60px;
    border-radius: 15px;
    background: var(--accent-gradient);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: var(--spacing-sm);
}

.project-icon i {
    font-size: 1.5rem;
    color: white;
}

.project-card h3 {
    font-size: var(--font-size-lg);
    margin-bottom: var(--spacing-sm);
}

.project-card p {
    color: var(--text-secondary);
    font-size: var(--font-size-xs);
    line-height: 1.6;
    margin-bottom: var(--spacing-sm);
}

.project-link {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--accent-primary);
    font-weight: 600;
    font-size: var(--font-size-xs);
    margin-top: var(--spacing-sm);
}

.project-link:hover {
    gap: 1rem;
}

.project-link i {
    transition: transform var(--transition-fast);
}

.project-link:hover i {
    transform: translateX(5px);
}

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

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

.contact-text {
    font-size: var(--font-size-md);
    color: var(--text-secondary);
    margin-bottom: var(--spacing-lg);
    line-height: 1.8;
}

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

.contact-btn {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md);
    background: var(--card-bg);
    border-radius: 20px;
    box-shadow: var(--card-shadow);
    transition: all var(--transition-base);
    min-width: 150px;
}

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

.contact-btn i {
    font-size: 2rem;
    color: var(--accent-primary);
}

.contact-btn span {
    font-weight: 600;
}

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

.footer p {
    margin: 0.5rem 0;
    font-size: var(--font-size-xs);
}

/* ===== Responsive Design ===== */
@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: 70px;
        left: -100%;
        width: 100%;
        flex-direction: column;
        background: var(--navbar-bg);
        backdrop-filter: blur(10px);
        padding: 2rem;
        gap: 1rem;
        transition: left var(--transition-base);
        box-shadow: var(--card-shadow);
    }

    .nav-menu.active {
        left: 0;
    }

    .hamburger {
        display: flex;
    }

    .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);
    }

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

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

    .hero-stats {
        gap: var(--spacing-md);
    }

    .timeline::before {
        left: 20px;
    }

    .timeline-marker {
        left: 20px;
    }

    .timeline-item:nth-child(odd) .timeline-content,
    .timeline-item:nth-child(even) .timeline-content {
        margin-left: 60px;
        margin-right: 0;
        text-align: left;
        width: calc(100% - 60px);
    }

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

@media (max-width: 480px) {
    :root {
        --font-size-3xl: 2.5rem;
        --font-size-2xl: 2rem;
    }

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

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

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

/* ===== Animations ===== */
.fade-in {
    animation: fadeIn 0.5s ease;
}

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

.slide-in-left {
    animation: slideInLeft 0.5s ease;
}

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

.slide-in-right {
    animation: slideInRight 0.5s ease;
}

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