/* Modern Portfolio CSS - Mobile-First Responsive Design */

/* CSS Custom Properties for Theming */
:root {
    /* Colors - Light Theme */
    --primary-color: #6366f1;
    --primary-light: #818cf8;
    --primary-dark: #4f46e5;
    --secondary-color: #f59e0b;
    --accent-color: #06d6a0;
    
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #f1f5f9;
    --bg-card: #ffffff;
    --bg-overlay: rgba(255, 255, 255, 0.95);
    
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-muted: #94a3b8;
    --text-inverse: #ffffff;
    
    --border-color: #e2e8f0;
    --border-light: #f1f5f9;
    --shadow-color: rgba(15, 23, 42, 0.08);
    --shadow-strong: rgba(15, 23, 42, 0.15);
    
    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, 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: 1.875rem;
    --font-size-4xl: 2.25rem;
    --font-size-5xl: 3rem;
    
    --font-weight-light: 300;
    --font-weight-normal: 400;
    --font-weight-medium: 500;
    --font-weight-semibold: 600;
    --font-weight-bold: 700;
    
    --line-height-tight: 1.25;
    --line-height-normal: 1.5;
    --line-height-relaxed: 1.75;
    
    /* Spacing */
    --space-1: 0.25rem;
    --space-2: 0.5rem;
    --space-3: 0.75rem;
    --space-4: 1rem;
    --space-5: 1.25rem;
    --space-6: 1.5rem;
    --space-8: 2rem;
    --space-10: 2.5rem;
    --space-12: 3rem;
    --space-16: 4rem;
    --space-20: 5rem;
    --space-24: 6rem;
    
    /* Layout */
    --container-max-width: 1200px;
    --container-padding: 1rem;
    --nav-height: 70px;
    --section-padding: 4rem 0;
    
    /* Borders & Radius */
    --border-radius-sm: 0.375rem;
    --border-radius: 0.5rem;
    --border-radius-lg: 0.75rem;
    --border-radius-xl: 1rem;
    --border-radius-full: 9999px;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px 0 var(--shadow-color);
    --shadow: 0 1px 3px 0 var(--shadow-color), 0 1px 2px -1px var(--shadow-color);
    --shadow-md: 0 4px 6px -1px var(--shadow-color), 0 2px 4px -2px var(--shadow-color);
    --shadow-lg: 0 10px 15px -3px var(--shadow-color), 0 4px 6px -4px var(--shadow-color);
    --shadow-xl: 0 20px 25px -5px var(--shadow-strong), 0 8px 10px -6px var(--shadow-color);
    
    /* Transitions */
    --transition-fast: 150ms ease-in-out;
    --transition-normal: 250ms ease-in-out;
    --transition-slow: 350ms ease-in-out;
    
    /* Z-index */
    --z-dropdown: 1000;
    --z-sticky: 1020;
    --z-fixed: 1030;
    --z-modal: 1040;
    --z-popover: 1050;
    --z-tooltip: 1060;
}

/* Dark Theme */
[data-theme="dark"] {
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-tertiary: #334155;
    --bg-card: #1e293b;
    --bg-overlay: rgba(15, 23, 42, 0.95);
    
    --text-primary: #f8fafc;
    --text-secondary: #cbd5e1;
    --text-muted: #94a3b8;
    
    --border-color: #334155;
    --border-light: #475569;
    --shadow-color: rgba(0, 0, 0, 0.3);
    --shadow-strong: rgba(0, 0, 0, 0.5);
}

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
    line-height: var(--line-height-normal);
}

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

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: var(--font-weight-semibold);
    line-height: var(--line-height-tight);
    color: var(--text-primary);
    margin-bottom: var(--space-4);
}

h1 { font-size: var(--font-size-4xl); }
h2 { font-size: var(--font-size-3xl); }
h3 { font-size: var(--font-size-2xl); }
h4 { font-size: var(--font-size-xl); }
h5 { font-size: var(--font-size-lg); }
h6 { font-size: var(--font-size-base); }

p {
    color: var(--text-secondary);
    line-height: var(--line-height-relaxed);
    margin-bottom: var(--space-4);
}

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

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

/* Loading Screen */
.loading-screen {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--bg-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: var(--z-modal);
    transition: opacity var(--transition-slow), visibility var(--transition-slow);
}

.loading-screen.hidden {
    opacity: 0;
    visibility: hidden;
}

.loader {
    text-align: center;
}

.loader-ring {
    width: 60px;
    height: 60px;
    border: 3px solid var(--border-color);
    border-top: 3px solid var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 0 auto var(--space-4);
}

.loader-text {
    color: var(--text-secondary);
    font-weight: var(--font-weight-medium);
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* Container */
.container {
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: 0 var(--container-padding);
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--nav-height);
    background: var(--bg-overlay);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    z-index: var(--z-fixed);
    transition: all var(--transition-normal);
}

.nav-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 100%;
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: 0 var(--container-padding);
}

.nav-brand {
    display: flex;
    align-items: center;
    font-weight: var(--font-weight-bold);
    font-size: var(--font-size-lg);
    color: var(--text-primary);
    text-decoration: none;
}

.brand-icon {
    width: 40px;
    height: 40px;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    border-radius: var(--border-radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-weight: var(--font-weight-bold);
    margin-right: var(--space-3);
}

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

/* Navigation Menu - Mobile First */
.nav-menu {
    position: fixed;
    top: var(--nav-height);
    left: 0;
    right: 0;
    background: var(--bg-card);
    padding: var(--space-6);
    display: flex;
    flex-direction: column;
    gap: var(--space-4);
    transform: translateY(-100%);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-normal);
    border-bottom: 1px solid var(--border-color);
    box-shadow: var(--shadow-lg);
}

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

.nav-link {
    font-weight: var(--font-weight-medium);
    color: var(--text-secondary);
    padding: var(--space-3) 0;
    position: relative;
    transition: color var(--transition-fast);
}

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

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 30px;
    height: 2px;
    background: var(--primary-color);
    border-radius: var(--border-radius-full);
}

/* Navigation Controls */
.nav-controls {
    display: flex;
    align-items: center;
    gap: var(--space-3);
}

.theme-toggle,
.nav-toggle {
    width: 44px;
    height: 44px;
    border: none;
    background: var(--bg-secondary);
    color: var(--text-secondary);
    border-radius: var(--border-radius);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.theme-toggle:hover,
.nav-toggle:hover {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

.nav-toggle {
    flex-direction: column;
    gap: 4px;
}

.nav-toggle span {
    width: 20px;
    height: 2px;
    background: currentColor;
    border-radius: var(--border-radius-full);
    transition: all var(--transition-fast);
}

.nav-toggle.active span:nth-child(1) {
    transform: rotate(45deg) translate(6px, 6px);
}

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

.nav-toggle.active span:nth-child(3) {
    transform: rotate(-45deg) translate(6px, -6px);
}

/* Desktop Navigation */
@media (min-width: 768px) {
    .nav-menu {
        position: static;
        flex-direction: row;
        background: transparent;
        padding: 0;
        transform: none;
        opacity: 1;
        visibility: visible;
        border: none;
        box-shadow: none;
    }
    
    .nav-toggle {
        display: none;
    }
    
    .nav-link {
        padding: var(--space-2) var(--space-4);
    }
    
    .nav-link.active::after {
        bottom: -10px;
    }
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-3) var(--space-6);
    font-weight: var(--font-weight-medium);
    font-size: var(--font-size-sm);
    line-height: 1;
    text-decoration: none;
    border: none;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: all var(--transition-fast);
    position: relative;
    overflow: hidden;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    color: white;
    box-shadow: var(--shadow-md);
}

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

.btn-secondary {
    background: var(--bg-secondary);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

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

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    position: relative;
    padding: calc(var(--nav-height) + 2rem) 0 var(--space-16);
    overflow: hidden;
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
}

.hero-particles {
    position: absolute;
    width: 100%;
    height: 100%;
    background-image: 
        radial-gradient(circle at 20% 20%, var(--primary-color) 1px, transparent 1px),
        radial-gradient(circle at 80% 80%, var(--accent-color) 1px, transparent 1px),
        radial-gradient(circle at 40% 60%, var(--secondary-color) 1px, transparent 1px);
    background-size: 100px 100px, 150px 150px, 120px 120px;
    opacity: 0.1;
    animation: float 20s infinite linear;
}

@keyframes float {
    0% { transform: translateY(0px) rotate(0deg); }
    50% { transform: translateY(-20px) rotate(180deg); }
    100% { transform: translateY(0px) rotate(360deg); }
}

.hero-content {
    display: grid;
    gap: var(--space-12);
    align-items: center;
    position: relative;
    z-index: 1;
}

.hero-greeting {
    font-size: var(--font-size-lg);
    color: var(--primary-color);
    font-weight: var(--font-weight-medium);
    margin-bottom: var(--space-2);
}

.hero-title {
    margin-bottom: var(--space-6);
}

.title-main {
    display: block;
    font-size: var(--font-size-4xl);
    font-weight: var(--font-weight-bold);
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: var(--space-2);
}

.title-sub {
    display: block;
    font-size: var(--font-size-xl);
    color: var(--text-secondary);
    font-weight: var(--font-weight-medium);
}

.hero-description {
    font-size: var(--font-size-lg);
    color: var(--text-secondary);
    line-height: var(--line-height-relaxed);
    margin-bottom: var(--space-8);
    max-width: 600px;
}

.hero-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
    gap: var(--space-6);
    margin-bottom: var(--space-8);
}

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

.stat-number {
    display: block;
    font-size: var(--font-size-2xl);
    font-weight: var(--font-weight-bold);
    color: var(--primary-color);
    margin-bottom: var(--space-1);
}

.stat-label {
    font-size: var(--font-size-sm);
    color: var(--text-muted);
    font-weight: var(--font-weight-medium);
}

.hero-cta {
    display: flex;
    gap: var(--space-4);
    flex-wrap: wrap;
}

.hero-visual {
    position: relative;
    display: flex;
    justify-content: center;
    align-items: center;
}

.hero-image {
    position: relative;
    width: 300px;
    height: 300px;
    border-radius: var(--border-radius-xl);
    overflow: hidden;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-xl);
}

.profile-image {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: center;
}

.image-placeholder {
    font-size: 120px;
    color: white;
    opacity: 0.8;
}

.floating-elements {
    position: absolute;
    width: 100%;
    height: 100%;
}

.floating-tech {
    position: absolute;
    width: 60px;
    height: 60px;
    background: var(--bg-card);
    border-radius: var(--border-radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    color: var(--primary-color);
    box-shadow: var(--shadow-lg);
    animation: floating 3s ease-in-out infinite;
}

.floating-tech:nth-child(1) {
    top: 20%;
    right: -10%;
    animation-delay: 0s;
}

.floating-tech:nth-child(2) {
    bottom: 30%;
    left: -10%;
    animation-delay: 1s;
}

.floating-tech:nth-child(3) {
    top: 60%;
    right: -5%;
    animation-delay: 2s;
}

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

.scroll-indicator {
    position: absolute;
    bottom: var(--space-8);
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    color: var(--text-muted);
}

.scroll-arrow {
    animation: bounce 2s infinite;
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% { transform: translateY(0); }
    40% { transform: translateY(-10px); }
    60% { transform: translateY(-5px); }
}

/* Desktop Hero Layout */
@media (min-width: 768px) {
    .hero-content {
        grid-template-columns: 1fr 1fr;
    }
    
    .title-main {
        font-size: var(--font-size-5xl);
    }
    
    .title-sub {
        font-size: var(--font-size-2xl);
    }
    
    .hero-stats {
        grid-template-columns: repeat(3, 1fr);
    }
}

/* Section Styles */
section {
    padding: var(--section-padding);
    position: relative;
}

.section-header {
    text-align: center;
    margin-bottom: var(--space-16);
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.section-tag {
    display: inline-block;
    padding: var(--space-2) var(--space-4);
    background: var(--primary-color);
    color: white;
    font-size: var(--font-size-sm);
    font-weight: var(--font-weight-medium);
    border-radius: var(--border-radius-full);
    margin-bottom: var(--space-4);
}

.section-title {
    font-size: var(--font-size-3xl);
    font-weight: var(--font-weight-bold);
    margin-bottom: var(--space-4);
}

.section-subtitle {
    font-size: var(--font-size-lg);
    color: var(--text-secondary);
    line-height: var(--line-height-relaxed);
}

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

.about-content {
    display: grid;
    gap: var(--space-12);
    align-items: start;
}

.about-story p {
    font-size: var(--font-size-lg);
    margin-bottom: var(--space-6);
}

.about-highlights {
    display: grid;
    gap: var(--space-6);
    margin-top: var(--space-8);
}

.highlight-item {
    display: flex;
    gap: var(--space-4);
    padding: var(--space-6);
    background: var(--bg-card);
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow);
}

.highlight-item i {
    font-size: 24px;
    color: var(--primary-color);
    flex-shrink: 0;
    margin-top: var(--space-1);
}

.highlight-item h4 {
    margin-bottom: var(--space-2);
}

.highlight-item p {
    margin: 0;
    color: var(--text-muted);
    font-size: var(--font-size-sm);
}

.skills-preview {
    background: var(--bg-card);
    padding: var(--space-8);
    border-radius: var(--border-radius-xl);
    box-shadow: var(--shadow-lg);
}

.skill-category {
    margin-bottom: var(--space-6);
}

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

.skill-category h4 {
    margin-bottom: var(--space-4);
    color: var(--text-primary);
}

.skill-tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-2);
}

.skill-tag {
    padding: var(--space-2) var(--space-3);
    background: var(--bg-secondary);
    color: var(--text-secondary);
    font-size: var(--font-size-sm);
    border-radius: var(--border-radius);
    border: 1px solid var(--border-color);
}

@media (min-width: 768px) {
    .about-content {
        grid-template-columns: 1fr 1fr;
    }
    
    .about-highlights {
        grid-template-columns: 1fr;
    }
}

/* Skills Section */
.skills-grid {
    display: grid;
    gap: var(--space-8);
}

.skill-card {
    background: var(--bg-card);
    padding: var(--space-8);
    border-radius: var(--border-radius-xl);
    box-shadow: var(--shadow);
    transition: all var(--transition-normal);
    border: 1px solid var(--border-color);
}

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

.skill-icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    border-radius: var(--border-radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    color: white;
    margin-bottom: var(--space-6);
}

.skill-card h3 {
    margin-bottom: var(--space-4);
}

.skill-card p {
    margin-bottom: var(--space-6);
    color: var(--text-secondary);
}

.skill-tech {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-2);
    margin-bottom: var(--space-6);
}

.skill-tech span {
    padding: var(--space-1) var(--space-3);
    background: var(--primary-color);
    color: white;
    font-size: var(--font-size-xs);
    border-radius: var(--border-radius);
    font-weight: var(--font-weight-medium);
}

.skill-progress {
    height: 6px;
    background: var(--bg-secondary);
    border-radius: var(--border-radius-full);
    overflow: hidden;
}

.progress-bar {
    height: 100%;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    border-radius: var(--border-radius-full);
    width: 0;
    transition: width 1s ease-in-out;
}

@media (min-width: 640px) {
    .skills-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (min-width: 1024px) {
    .skills-grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

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

.projects-grid {
    display: grid;
    gap: var(--space-8);
}

.project-card {
    background: var(--bg-card);
    border-radius: var(--border-radius-xl);
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: all var(--transition-normal);
    border: 1px solid var(--border-color);
}

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

.project-image {
    position: relative;
    height: 200px;
    background: var(--bg-tertiary);
    overflow: hidden;
}

.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 var(--transition-normal);
}

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

.project-links {
    display: flex;
    gap: var(--space-4);
}

.project-link {
    width: 50px;
    height: 50px;
    background: var(--primary-color);
    color: white;
    border-radius: var(--border-radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    text-decoration: none;
    transition: all var(--transition-fast);
}

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

.project-placeholder {
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 48px;
    color: var(--text-muted);
}

.project-content {
    padding: var(--space-8);
}

.project-content h3 {
    margin-bottom: var(--space-4);
}

.project-content p {
    margin-bottom: var(--space-6);
    color: var(--text-secondary);
}

.project-tech {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-2);
    margin-bottom: var(--space-6);
}

.project-tech span {
    padding: var(--space-1) var(--space-3);
    background: var(--bg-secondary);
    color: var(--text-secondary);
    font-size: var(--font-size-xs);
    border-radius: var(--border-radius);
    border: 1px solid var(--border-color);
}

.project-stats {
    display: flex;
    gap: var(--space-6);
}

.stat {
    text-align: center;
}

.stat-value {
    display: block;
    font-size: var(--font-size-lg);
    font-weight: var(--font-weight-bold);
    color: var(--primary-color);
}

.stat-label {
    font-size: var(--font-size-xs);
    color: var(--text-muted);
    font-weight: var(--font-weight-medium);
}

@media (min-width: 768px) {
    .projects-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (min-width: 1024px) {
    .projects-grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

/* Experience Section */
.timeline {
    position: relative;
    max-width: 800px;
    margin: 0 auto;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 30px;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--border-color);
}

.timeline-item {
    position: relative;
    margin-bottom: var(--space-12);
    padding-left: calc(60px + var(--space-6));
}

.timeline-marker {
    position: absolute;
    left: 0;
    top: 0;
    width: 60px;
    height: 60px;
    background: var(--bg-card);
    border: 3px solid var(--primary-color);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1;
}

.timeline-icon {
    font-size: 20px;
    color: var(--primary-color);
}

.timeline-content {
    background: var(--bg-card);
    padding: var(--space-8);
    border-radius: var(--border-radius-xl);
    box-shadow: var(--shadow);
    border: 1px solid var(--border-color);
}

.timeline-header {
    margin-bottom: var(--space-6);
}

.timeline-header h3 {
    margin-bottom: var(--space-2);
    color: var(--text-primary);
}

.timeline-company {
    display: block;
    font-weight: var(--font-weight-medium);
    color: var(--primary-color);
    margin-bottom: var(--space-1);
}

.timeline-period {
    font-size: var(--font-size-sm);
    color: var(--text-muted);
    font-weight: var(--font-weight-medium);
}

.timeline-content p {
    margin-bottom: var(--space-6);
}

.timeline-achievements {
    list-style: none;
    margin-bottom: var(--space-6);
}

.timeline-achievements li {
    position: relative;
    padding-left: var(--space-6);
    margin-bottom: var(--space-3);
    color: var(--text-secondary);
}

.timeline-achievements li::before {
    content: '•';
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: bold;
}

.timeline-tech {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-2);
}

.timeline-tech span {
    padding: var(--space-1) var(--space-3);
    background: var(--primary-color);
    color: white;
    font-size: var(--font-size-xs);
    border-radius: var(--border-radius);
    font-weight: var(--font-weight-medium);
}

@media (min-width: 768px) {
    .timeline::before {
        left: 50%;
        transform: translateX(-50%);
    }
    
    .timeline-item {
        width: 50%;
        padding-left: 0;
        padding-right: var(--space-8);
    }
    
    .timeline-item:nth-child(even) {
        left: 50%;
        padding-left: var(--space-8);
        padding-right: 0;
    }
    
    .timeline-marker {
        left: 50%;
        transform: translateX(-50%);
    }
    
    .timeline-item:nth-child(even) .timeline-marker {
        left: 50%;
        transform: translateX(-50%);
    }
}

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

.contact-content {
    display: grid;
    gap: var(--space-12);
    align-items: start;
}

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

.contact-grid {
    display: grid;
    gap: var(--space-6);
    margin-bottom: var(--space-12);
}

.contact-item {
    display: flex;
    gap: var(--space-4);
    padding: var(--space-6);
    background: var(--bg-card);
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow);
    border: 1px solid var(--border-color);
    transition: all var(--transition-base);
}

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

.contact-icon {
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    border-radius: var(--border-radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
    color: white;
    flex-shrink: 0;
}

.contact-details h4 {
    margin-bottom: var(--space-2);
    color: var(--text-primary);
    font-weight: var(--font-weight-semibold);
}

.contact-details p {
    margin-bottom: var(--space-2);
    color: var(--text-secondary);
    font-size: var(--font-size-lg);
}

.contact-link {
    font-size: var(--font-size-sm);
    font-weight: var(--font-weight-medium);
    color: var(--primary-color);
    text-decoration: none;
    padding: var(--space-2) var(--space-4);
    border: 1px solid var(--primary-color);
    border-radius: var(--border-radius);
    display: inline-block;
    transition: all var(--transition-fast);
}

.contact-link:hover {
    background: var(--primary-color);
    color: white;
    transform: translateY(-1px);
}

.contact-availability {
    font-size: var(--font-size-sm);
    color: var(--text-muted);
    font-style: italic;
    margin-top: var(--space-2);
}

.contact-cta {
    background: var(--bg-card);
    padding: var(--space-8);
    border-radius: var(--border-radius-xl);
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--border-color);
    margin-bottom: var(--space-12);
}

.contact-cta h3 {
    color: var(--text-primary);
    margin-bottom: var(--space-4);
    font-size: var(--font-size-2xl);
    font-weight: var(--font-weight-bold);
}

.contact-cta p {
    color: var(--text-secondary);
    margin-bottom: var(--space-6);
    font-size: var(--font-size-lg);
}

.cta-buttons {
    display: flex;
    gap: var(--space-4);
    justify-content: center;
    flex-wrap: wrap;
}

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

.social-links h4 {
    color: var(--text-primary);
    margin-bottom: var(--space-4);
    font-size: var(--font-size-lg);
    font-weight: var(--font-weight-semibold);
}

.social-items {
    display: flex;
    gap: var(--space-6);
    justify-content: center;
    flex-wrap: wrap;
}

.social-link {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-3) var(--space-6);
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-lg);
    font-size: var(--font-size-base);
    color: var(--text-secondary);
    text-decoration: none;
    transition: all var(--transition-fast);
    font-weight: var(--font-weight-medium);
}

.social-link:hover {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.social-link i {
    font-size: 20px;
}

@media (min-width: 768px) {
    .contact-grid {
        grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    }
    
    .cta-buttons {
        flex-wrap: nowrap;
    }
}

/* Footer */
.footer {
    background: var(--bg-tertiary);
    padding: var(--space-16) 0 var(--space-8);
    text-align: center;
}

.footer-content {
    margin-bottom: var(--space-8);
}

.footer-brand {
    display: inline-flex;
    align-items: center;
    font-weight: var(--font-weight-bold);
    font-size: var(--font-size-lg);
    color: var(--text-primary);
    margin-bottom: var(--space-4);
}

.footer-brand .brand-icon {
    margin-right: var(--space-3);
}

.footer-text {
    font-size: var(--font-size-lg);
    color: var(--text-secondary);
    margin-bottom: var(--space-8);
    max-width: 400px;
    margin-left: auto;
    margin-right: auto;
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: var(--space-6);
    flex-wrap: wrap;
}

.footer-links a {
    color: var(--text-secondary);
    font-weight: var(--font-weight-medium);
    transition: color var(--transition-fast);
}

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

.footer-bottom {
    border-top: 1px solid var(--border-color);
    padding-top: var(--space-8);
    display: flex;
    justify-content: center;
    gap: var(--space-4);
    flex-wrap: wrap;
    font-size: var(--font-size-sm);
    color: var(--text-muted);
}

.footer-bottom i {
    color: #ef4444;
}

/* Back to Top Button */
.back-to-top {
    position: fixed;
    bottom: var(--space-6);
    right: var(--space-6);
    width: 50px;
    height: 50px;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: var(--border-radius-lg);
    cursor: pointer;
    box-shadow: var(--shadow-lg);
    transition: all var(--transition-fast);
    opacity: 0;
    visibility: hidden;
    transform: translateY(100px);
    z-index: var(--z-sticky);
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.back-to-top:hover {
    background: var(--primary-dark);
    transform: translateY(-5px);
}

/* Utility Classes */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.d-none { display: none; }
.d-block { display: block; }
.d-flex { display: flex; }
.d-grid { display: grid; }

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

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

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

.animate-fadeInUp {
    animation: fadeInUp 0.6s ease-out;
}

.animate-fadeInLeft {
    animation: fadeInLeft 0.6s ease-out;
}

.animate-fadeInRight {
    animation: fadeInRight 0.6s ease-out;
}

/* Responsive Design Enhancements */
@media (max-width: 480px) {
    :root {
        --container-padding: 1rem;
        --section-padding: 3rem 0;
    }
    
    .title-main {
        font-size: var(--font-size-3xl);
    }
    
    .title-sub {
        font-size: var(--font-size-lg);
    }
    
    .hero-cta {
        flex-direction: column;
    }
    
    .btn {
        justify-content: center;
        width: 100%;
    }
}

/* Print Styles */
@media print {
    .navbar,
    .hero-particles,
    .floating-elements,
    .scroll-indicator,
    .back-to-top,
    .loading-screen {
        display: none !important;
    }
    
    body {
        background: white !important;
        color: black !important;
    }
    
    .hero {
        min-height: auto;
        padding: 2rem 0;
    }
    
    section {
        padding: 2rem 0;
        break-inside: avoid;
    }
}

/* Certifications Section */
.certifications {
    padding: var(--section-padding);
    background: var(--bg-secondary);
}

.certifications-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 3rem;
    margin-top: 3rem;
}

.cert-category h3 {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 1.5rem;
    text-align: center;
    position: relative;
}

.cert-category h3:after {
    content: '';
    position: absolute;
    bottom: -0.5rem;
    left: 50%;
    transform: translateX(-50%);
    width: 3rem;
    height: 3px;
    background: var(--primary-color);
    border-radius: 2px;
}

.cert-items {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.cert-item {
    background: var(--bg-card);
    border-radius: var(--border-radius-lg);
    padding: 1.5rem;
    display: flex;
    align-items: center;
    gap: 1rem;
    box-shadow: var(--shadow-sm);
    border: 2px solid transparent;
    transition: all var(--transition-base);
}

.cert-item:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-light);
}

.cert-item.completed {
    border-left: 4px solid var(--accent-color);
}

.cert-icon {
    width: 3rem;
    height: 3rem;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    border-radius: var(--border-radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.25rem;
    flex-shrink: 0;
}

.cert-item.completed .cert-icon {
    background: linear-gradient(135deg, var(--accent-color), #48cc82);
}

.cert-info h4 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.25rem;
    line-height: 1.4;
}

.cert-date {
    font-size: 0.875rem;
    color: var(--text-secondary);
    font-weight: 500;
}