/* ==========================================
   CSS Variables - Enhanced Dark Theme
   ========================================== */
:root {
    /* Colors */
    --bg-primary: #0a0a0f;
    --bg-secondary: #12121a;
    --bg-tertiary: #1a1a28;
    --text-primary: #e8e8f0;
    --text-secondary: #a8a8bc;
    --text-muted: #6b6b7f;
    --accent-primary: #00d4ff;
    --accent-secondary: #7c3aed;
    --accent-hover: #00b8e6;
    --border-color: #2a2a3c;
    --shadow: rgba(0, 0, 0, 0.6);
    --glass-bg: rgba(26, 26, 40, 0.7);
    --glass-border: rgba(255, 255, 255, 0.1);
    
    /* Gradients */
    --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-accent: linear-gradient(135deg, #00d4ff 0%, #7c3aed 100%);
    --gradient-mesh: 
        radial-gradient(at 40% 20%, rgba(102, 126, 234, 0.15) 0px, transparent 50%),
        radial-gradient(at 80% 0%, rgba(124, 58, 237, 0.15) 0px, transparent 50%),
        radial-gradient(at 0% 50%, rgba(0, 212, 255, 0.1) 0px, transparent 50%);
    
    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-size-base: 16px;
    --font-size-sm: 0.875rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.5rem;
    --font-size-2xl: 2rem;
    --font-size-3xl: 2.5rem;
    --font-size-4xl: 3rem;
    --line-height-base: 1.6;
    --line-height-tight: 1.3;
    
    /* Spacing */
    --space-xs: 0.5rem;
    --space-sm: 1rem;
    --space-md: 1.5rem;
    --space-lg: 2rem;
    --space-xl: 3rem;
    --space-2xl: 4rem;
    
    /* Layout */
    --sidebar-width: 40%;
    --content-width: 60%;
    --max-content-width: 800px;
    --border-radius: 16px;
    --border-radius-sm: 12px;
    
    /* Transitions */
    --transition-fast: 200ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 300ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 500ms cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
    font-size: var(--font-size-base);
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: var(--line-height-base);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    min-height: 100vh;
    overflow-x: hidden;
    position: relative;
}

body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--gradient-mesh);
    z-index: 0;
    pointer-events: none;
}

/* ==========================================
   Animated Particles Canvas
   ========================================== */
#particles-canvas {
    position: fixed;
    top: 0;
    left: 0;
    width: 40%;
    height: 100%;
    z-index: 1;
    pointer-events: none;
    opacity: 0.4;
}

/* ==========================================
   Language Toggle
   ========================================== */
.language-toggle {
    position: fixed;
    top: var(--space-lg);
    right: var(--space-lg);
    z-index: 1000;
}

.lang-btn {
    background: var(--glass-bg);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border: 1px solid var(--glass-border);
    border-radius: 999px;
    padding: var(--space-xs) var(--space-md);
    color: var(--text-secondary);
    font-family: var(--font-family);
    font-size: var(--font-size-sm);
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-base);
    display: flex;
    align-items: center;
    gap: var(--space-xs);
}

.lang-btn:hover {
    background: rgba(26, 26, 40, 0.9);
    border-color: var(--accent-primary);
    transform: translateY(-2px);
}

.lang-option {
    transition: color var(--transition-fast);
}

.lang-option.active {
    color: var(--accent-primary);
}

.lang-separator {
    color: var(--border-color);
}

/* ==========================================
   Split Layout Container
   ========================================== */
.split-container {
    display: flex;
    min-height: 100vh;
    position: relative;
    z-index: 2;
}

/* ==========================================
   Sidebar - Fixed Left (40%)
   ========================================== */
.sidebar {
    position: fixed;
    left: 0;
    top: 0;
    width: var(--sidebar-width);
    height: 100vh;
    padding: var(--space-md);
    display: flex;
    flex-direction: column;
    justify-content: center;
    overflow: hidden;
    z-index: 10;
}

.sidebar-content {
    max-width: 450px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: var(--space-md);
    padding: var(--space-md) 0;
}

/* Profile Section */
.profile-section {
    margin-bottom: var(--space-sm);
    animation: fadeInUp 0.8s ease-out;
}

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

.profile-image-container {
    display: flex;
    justify-content: flex-start;
    align-items: center;
    margin-bottom: var(--space-md);
}

.profile-image {
    width: 110px;
    height: 110px;
    border-radius: 50%;
    border: 3px solid var(--glass-border);
    object-fit: cover;
    transition: all var(--transition-slow);
    position: relative;
    box-shadow: 0 0 30px rgba(0, 212, 255, 0.3);
}

.profile-image:hover {
    transform: scale(1.05);
    border-color: var(--accent-primary);
    box-shadow: 0 0 40px rgba(0, 212, 255, 0.5);
}

/* Fallback for profile-image-placeholder if needed */
.profile-image-placeholder {
    width: 140px;
    height: 140px;
    border-radius: 50%;
    background: var(--gradient-accent);
    border: 3px solid var(--glass-border);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-primary);
    transition: all var(--transition-slow);
    position: relative;
    overflow: hidden;
}

.profile-image-placeholder::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: linear-gradient(45deg, transparent, rgba(255, 255, 255, 0.1), transparent);
    transform: rotate(45deg);
    animation: shimmer 3s infinite;
}

@keyframes shimmer {
    0% {
        transform: translateX(-100%) translateY(-100%) rotate(45deg);
    }
    100% {
        transform: translateX(100%) translateY(100%) rotate(45deg);
    }
}

.profile-image-placeholder svg {
    width: 70px;
    height: 70px;
    position: relative;
    z-index: 1;
}

.profile-image-placeholder:hover {
    transform: scale(1.05) rotate(5deg);
    border-color: var(--accent-primary);
}

.name {
    font-size: var(--font-size-2xl);
    font-weight: 700;
    margin-bottom: var(--space-xs);
    line-height: var(--line-height-tight);
    color: var(--accent-primary);
}

.title {
    font-size: 1rem;
    font-weight: 500;
    color: var(--accent-primary);
    margin-bottom: var(--space-sm);
    line-height: var(--line-height-tight);
}

.value-proposition {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* Sidebar Navigation */
.sidebar-nav {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
    margin-bottom: var(--space-md);
    animation: fadeInUp 0.8s ease-out 0.2s backwards;
}

.nav-link {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    padding: var(--space-xs) 0;
    color: var(--text-muted);
    text-decoration: none;
    font-size: 0.8rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    transition: all var(--transition-base);
    position: relative;
}

.nav-indicator {
    width: 30px;
    height: 2px;
    background: var(--text-muted);
    transition: all var(--transition-base);
}

.nav-link:hover .nav-indicator,
.nav-link.active .nav-indicator {
    width: 60px;
    background: var(--accent-primary);
}

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

.nav-text {
    transition: transform var(--transition-base);
}

.nav-link:hover .nav-text {
    transform: translateX(5px);
}

/* Social Links */
.social-links {
    display: flex;
    align-items: center;
    gap: var(--space-md);
    margin-top: var(--space-sm);
}

.social-link {
    color: var(--text-muted);
    text-decoration: none;
    transition: all var(--transition-base);
    display: flex;
    align-items: center;
    justify-content: center;
}

.social-link:hover {
    color: var(--accent-primary);
    transform: translateY(-3px);
}

.social-link svg {
    transition: all var(--transition-base);
}

/* ==========================================
   Main Content - Scrollable Right (60%)
   ========================================== */
.main-content {
    margin-left: var(--sidebar-width);
    width: var(--content-width);
    padding: var(--space-2xl);
    padding-right: var(--space-2xl);
}

/* Content Sections */
.content-section {
    margin-bottom: var(--space-2xl);
    padding: var(--space-2xl) 0;
    opacity: 0;
    transform: translateY(30px);
    transition: all var(--transition-slow);
}

.content-section.visible {
    opacity: 1;
    transform: translateY(0);
}

.section-header {
    display: grid;
    grid-template-columns: 40px 1fr;
    gap: var(--space-md);
    margin-bottom: var(--space-xl);
    align-items: baseline;
}

.section-number {
    font-size: var(--font-size-sm);
    font-weight: 700;
    color: var(--accent-primary);
    font-family: monospace;
    text-align: left;
}

.section-title {
    font-size: var(--font-size-2xl);
    font-weight: 700;
    color: var(--text-primary);
    position: relative;
}

.section-content {
    max-width: var(--max-content-width);
    display: grid;
    grid-template-columns: 40px 1fr;
    gap: var(--space-md);
}

/* ==========================================
   Glass Card Effect
   ========================================== */
.glass-card {
    background: var(--glass-bg);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border: 1px solid var(--glass-border);
    border-radius: var(--border-radius-sm);
    padding: var(--space-lg);
    transition: all var(--transition-base);
}

.glass-card:hover {
    background: rgba(26, 26, 40, 0.8);
    border-color: rgba(0, 212, 255, 0.3);
    transform: translateX(8px);
}

/* ==========================================
   About Section
   ========================================== */
.about-text {
    font-size: var(--font-size-lg);
    color: var(--text-secondary);
    line-height: 1.8;
    grid-column: 1 / -1;
}

/* ==========================================
   Timeline (Experience & Education)
   ========================================== */
.timeline-item {
    display: contents;
}

.timeline-marker {
    position: relative;
    width: 14px;
    height: 14px;
    background: var(--accent-primary);
    border: 3px solid var(--bg-primary);
    border-radius: 50%;
    box-shadow: 0 0 20px var(--accent-primary);
    animation: pulse 2s infinite;
    justify-self: start;
    align-self: flex-start;
    margin-top: calc(var(--space-lg) + 1rem - 7px);
}

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

@keyframes pulse {
    0%, 100% {
        box-shadow: 0 0 20px var(--accent-primary);
    }
    50% {
        box-shadow: 0 0 30px var(--accent-primary), 0 0 40px var(--accent-primary);
    }
}

.timeline-badge {
    margin-bottom: var(--space-md);
    display: flex;
    align-items: center;
    justify-content: flex-start;
}

.timeline-badge i {
    font-size: 2rem;
    color: var(--accent-primary);
    transition: all var(--transition-base);
    opacity: 0.75;
    filter: brightness(0.9);
}

.timeline-content:hover .timeline-badge i {
    transform: scale(1.1);
    color: var(--text-primary);
    opacity: 1;
    filter: brightness(1);
}

.timeline-period {
    font-size: var(--font-size-sm);
    color: var(--text-muted);
    margin-bottom: var(--space-sm);
    font-weight: 500;
}

.timeline-title {
    font-size: var(--font-size-xl);
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--space-sm);
    line-height: var(--line-height-tight);
}

.timeline-company {
    font-size: 1rem;
    color: var(--accent-primary);
    font-weight: 600;
    margin-bottom: var(--space-sm);
}

.timeline-field {
    font-size: 0.95rem;
    color: var(--text-secondary);
    margin-bottom: var(--space-sm);
    line-height: 1.6;
}

.timeline-description {
    font-size: 1rem;
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: var(--space-md);
}

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

.tech-tag {
    display: inline-block;
    padding: var(--space-xs) var(--space-sm);
    background: rgba(0, 212, 255, 0.1);
    border: 1px solid rgba(0, 212, 255, 0.2);
    border-radius: 6px;
    color: var(--accent-primary);
    font-size: 0.8rem;
    font-weight: 600;
}

.timeline-grade {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    margin-top: var(--space-md);
}

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

.grade-value {
    font-size: var(--font-size-xl);
    font-weight: 800;
    background: var(--gradient-accent);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* ==========================================
   Publications
   ========================================== */
.publication-card-link {
    text-decoration: none !important;
    display: block;
}

.publication-card-link:hover,
.publication-card-link:focus,
.publication-card-link:active,
.publication-card-link:visited {
    text-decoration: none !important;
}

.publication-card-link .timeline-title,
.publication-card-link .timeline-company {
    text-decoration: none !important;
}

.publication-card-link .glass-card {
    position: relative;
    transition: all 0.3s ease;
    cursor: pointer;
}

.publication-card-link:hover .glass-card {
    background: rgba(255, 255, 255, 0.08);
    border-color: rgba(139, 92, 246, 0.4);
    transform: translateX(5px);
}

.publication-arrow {
    position: absolute;
    top: 20px;
    right: 20px;
    color: var(--accent-primary);
    opacity: 0;
    transform: scale(0.8);
    transition: all 0.3s ease;
}

.publication-card-link:hover .publication-arrow {
    opacity: 1;
    transform: scale(1);
}

/* ==========================================
   Skills Grid
   ========================================== */
.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--space-md);
    grid-column: 1 / -1;
}

.skill-card {
    text-align: center;
    padding: var(--space-lg);
    cursor: default;
}

.skill-card:hover {
    transform: translateY(-4px);
}

.skill-icon {
    font-size: 2.5rem;
    margin-bottom: var(--space-sm);
    color: var(--accent-primary);
    transition: all var(--transition-base);
    opacity: 0.75;
    filter: brightness(0.9);
}

.skill-card:hover .skill-icon {
    transform: scale(1.1);
    color: var(--text-primary);
    opacity: 1;
    filter: brightness(1);
}

.skill-name {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
}

/* ==========================================
   Footer
   ========================================== */
.footer {
    text-align: center;
    padding: var(--space-2xl) 0;
    color: var(--text-muted);
    font-size: var(--font-size-sm);
    border-top: 1px solid var(--border-color);
    margin-top: var(--space-2xl);
}

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

/* Tablets and below */
@media (max-width: 1024px) {
    :root {
        --sidebar-width: 100%;
        --content-width: 100%;
    }

    #particles-canvas {
        width: 100%;
        opacity: 0.2;
    }

    .split-container {
        flex-direction: column;
    }

    .sidebar {
        position: relative;
        width: 100%;
        height: auto;
        min-height: 100vh;
        padding: var(--space-xl) var(--space-lg);
    }

    .sidebar-content {
        max-width: 600px;
    }

    .main-content {
        margin-left: 0;
        width: 100%;
        padding: var(--space-xl) var(--space-lg);
    }

    .language-toggle {
        top: var(--space-md);
        right: var(--space-md);
    }

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

    .profile-image-container {
        justify-content: center;
    }

    .sidebar-nav {
        align-items: center;
    }

    .nav-link {
        justify-content: center;
    }

    .social-links {
        justify-content: center;
    }
}

/* Mobile */
@media (max-width: 640px) {
    :root {
        --font-size-base: 15px;
        --space-lg: 1.5rem;
        --space-xl: 2rem;
        --space-2xl: 2.5rem;
    }

    .sidebar {
        padding: var(--space-lg) var(--space-md);
        min-height: auto;
    }

    .main-content {
        padding: var(--space-lg) var(--space-md);
    }

    .name {
        font-size: var(--font-size-2xl);
    }

    .title {
        font-size: 1rem;
    }

    .value-proposition {
        font-size: 0.95rem;
    }

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

    .skills-grid {
        grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
        gap: var(--space-sm);
    }

    .language-toggle {
        top: var(--space-sm);
        right: var(--space-sm);
    }
}

/* ==========================================
   Accessibility
   ========================================== */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

a:focus,
button:focus {
    outline: 2px solid var(--accent-primary);
    outline-offset: 2px;
}

::selection {
    background-color: var(--accent-primary);
    color: var(--bg-primary);
}

::-moz-selection {
    background-color: var(--accent-primary);
    color: var(--bg-primary);
}

/* ==========================================
   Smooth Scrollbar
   ========================================== */
::-webkit-scrollbar {
    width: 10px;
}

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

::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 5px;
}

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