/* ===== CSS VARIABLES ===== */
:root {
    --color-bg: #0d0d0d;
    --color-bg-secondary: #141414;
    --color-bg-tertiary: #1a1a1a;
    --color-surface: #1e1e1e;
    --color-border: #2a2a2a;
    --color-border-light: #404040;
    
    --color-text: #ffffff;
    --color-text-secondary: #b4b4b4;
    --color-text-muted: #808080;
    
    --color-primary: #ff6b35;
    --color-primary-dark: #e85a28;
    --color-primary-light: #ff8c61;
    
    --color-accent: #ff6b35;
    --color-accent-light: #ff8c61;
    
    --color-success: #22c55e;
    --color-warning: #ff6b35;
    --color-error: #ef4444;
    
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
    
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    --spacing-3xl: 4rem;
    --spacing-4xl: 6rem;
    
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-2xl: 1.5rem;
    --radius-full: 9999px;
    
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1);
    --shadow-glow: 0 0 40px -10px var(--color-primary);
    
    --transition-fast: 150ms ease;
    --transition-base: 200ms ease;
    --transition-slow: 300ms ease;
    
    --container-max: 1200px;
    --navbar-height: 72px;
}

/* ===== RESET & BASE ===== */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    scroll-padding-top: var(--navbar-height);
}

body {
    font-family: var(--font-sans);
    font-size: 16px;
    line-height: 1.6;
    color: var(--color-text);
    background-color: var(--color-bg);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
}

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

a {
    color: inherit;
    text-decoration: none;
}

button {
    font-family: inherit;
    cursor: pointer;
    border: none;
    background: none;
}

ul, ol {
    list-style: none;
}

/* ===== UTILITIES ===== */
.container {
    width: 100%;
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

.section-header {
    text-align: center;
    margin-bottom: var(--spacing-4xl);
}

.section-tag {
    display: inline-block;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--color-primary);
    background: rgba(59, 130, 246, 0.1);
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--radius-full);
    margin-bottom: var(--spacing-md);
}

.section-title {
    font-size: clamp(2rem, 5vw, 3rem);
    font-weight: 700;
    letter-spacing: -0.02em;
    margin-bottom: var(--spacing-md);
    background: linear-gradient(135deg, var(--color-text) 0%, var(--color-text-secondary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.section-subtitle {
    font-size: 1.125rem;
    color: var(--color-text-secondary);
    max-width: 600px;
    margin: 0 auto;
}

/* ===== BUTTONS ===== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md) var(--spacing-xl);
    font-size: 0.9375rem;
    font-weight: 500;
    border-radius: var(--radius-lg);
    transition: all var(--transition-base);
}

.btn-primary {
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
    color: white;
    box-shadow: 0 4px 14px -3px rgba(255, 107, 53, 0.5);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    font-size: 0.875rem;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 24px -3px rgba(255, 107, 53, 0.6);
    background: linear-gradient(135deg, var(--color-primary-light) 0%, var(--color-primary) 100%);
}

.btn-secondary {
    background: transparent;
    color: var(--color-text);
    border: 1px solid var(--color-border-light);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    font-size: 0.875rem;
}

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

/* ===== NAVBAR ===== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--navbar-height);
    z-index: 1000;
    background: rgba(10, 10, 11, 0.8);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid transparent;
    transition: all var(--transition-base);
}

.navbar.scrolled {
    background: rgba(13, 13, 13, 0.98);
    border-bottom-color: var(--color-border);
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.5);
}

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

.nav-logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--color-text);
}

.logo-icon {
    width: 32px;
    height: 32px;
    border-radius: var(--radius-md);
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.nav-link {
    padding: var(--spacing-sm) var(--spacing-md);
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--color-text-secondary);
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
}

.nav-link:hover {
    color: var(--color-text);
    background: var(--color-surface);
}

.nav-actions {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.lang-switch {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--color-surface);
    border-radius: var(--radius-full);
    font-size: 0.8125rem;
    font-weight: 500;
}

.lang-option {
    color: var(--color-text-muted);
    transition: color var(--transition-fast);
    cursor: pointer;
}

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

.lang-option:hover {
    color: var(--color-text);
}

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

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    padding: var(--spacing-sm);
}

.nav-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--color-text);
    border-radius: 2px;
    transition: all var(--transition-fast);
}

.nav-toggle.active span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
}

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

.nav-toggle.active span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
}

/* ===== HERO SECTION ===== */
.hero {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    padding-top: var(--navbar-height);
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 150%;
    height: 100%;
    background: radial-gradient(ellipse at center top, rgba(59, 130, 246, 0.08) 0%, transparent 50%);
    pointer-events: none;
}

.hero-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-4xl);
    align-items: center;
    max-width: var(--container-max);
    margin: 0 auto;
    padding: var(--spacing-4xl) var(--spacing-lg);
}

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

.hero-subtitle {
    font-size: 0.875rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.15em;
    color: var(--color-primary);
    margin-bottom: var(--spacing-md);
}

.hero-title {
    font-size: clamp(2.5rem, 6vw, 4rem);
    font-weight: 800;
    letter-spacing: -0.03em;
    line-height: 1.1;
    margin-bottom: var(--spacing-lg);
    background: linear-gradient(135deg, var(--color-text) 0%, var(--color-text-secondary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-tagline {
    font-size: 1.25rem;
    font-weight: 500;
    color: var(--color-text);
    margin-bottom: var(--spacing-lg);
    padding-left: var(--spacing-md);
    border-left: 3px solid var(--color-primary);
}

.hero-description {
    font-size: 1rem;
    color: var(--color-text-secondary);
    line-height: 1.8;
    margin-bottom: var(--spacing-xl);
}

.hero-cta {
    display: flex;
    gap: var(--spacing-md);
    flex-wrap: wrap;
}

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

.hero-image-wrapper {
    position: relative;
    width: 100%;
    max-width: 400px;
}

.hero-image {
    width: 100%;
    aspect-ratio: 1;
    object-fit: cover;
    border-radius: var(--radius-2xl);
    border: 1px solid var(--color-border);
    box-shadow: var(--shadow-xl);
}

.hero-image-decoration {
    position: absolute;
    inset: -20px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-2xl);
    z-index: -1;
    opacity: 0.5;
}

.hero-image-decoration::before {
    content: '';
    position: absolute;
    top: 40px;
    left: 40px;
    right: -40px;
    bottom: -40px;
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-accent) 100%);
    opacity: 0.1;
    border-radius: var(--radius-2xl);
    z-index: -2;
}

.hero-scroll {
    position: absolute;
    bottom: var(--spacing-xl);
    left: 50%;
    transform: translateX(-50%);
}

.scroll-indicator {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-sm);
    color: var(--color-text-muted);
    font-size: 0.75rem;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    animation: bounce 2s infinite;
}

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

/* ===== PROJECTS SECTION ===== */
.projects {
    padding: var(--spacing-4xl) 0;
    background: var(--color-bg-secondary);
}

.project-card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
    margin-bottom: var(--spacing-2xl);
    opacity: 0;
    transform: translateY(30px);
    transition: all var(--transition-slow);
    overflow: hidden;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
}

.project-card:hover {
    border-color: var(--color-primary);
    box-shadow: 0 8px 24px rgba(255, 107, 53, 0.15), 0 0 0 1px var(--color-primary);
    transform: translateY(-4px);
}

.project-card.visible {
    opacity: 1;
    transform: translateY(0);
}

.project-card-inner {
    display: flex;
    gap: var(--spacing-2xl);
    padding: var(--spacing-2xl);
}

.project-left {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-lg);
    min-width: 100px;
    padding-right: var(--spacing-xl);
    border-right: 1px solid var(--color-border);
}

.project-number {
    font-size: 2.5rem;
    font-weight: 800;
    background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    line-height: 1;
}

.project-icon-wrapper {
    width: 64px;
    height: 64px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--color-bg);
    border-radius: var(--radius-lg);
    border: 1px solid var(--color-border);
    transition: all var(--transition-base);
}

.project-card:hover .project-icon-wrapper {
    background: linear-gradient(135deg, rgba(255, 107, 53, 0.15), rgba(255, 140, 97, 0.15));
    border-color: var(--color-primary);
    box-shadow: 0 0 20px rgba(255, 107, 53, 0.3);
}

.project-icon {
    color: var(--color-text-secondary);
    transition: all var(--transition-base);
}

.project-card:hover .project-icon {
    color: var(--color-primary);
}

.project-right {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

.project-header {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.project-title-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--spacing-md);
}

.project-title {
    font-size: 1.75rem;
    font-weight: 700;
    margin: 0;
}

.github-link {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    border-radius: var(--radius-md);
    background: var(--color-bg);
    border: 1px solid var(--color-border);
    color: var(--color-text-secondary);
    transition: all var(--transition-base);
}

.github-link:hover {
    background: var(--color-text);
    color: var(--color-bg);
    border-color: var(--color-text);
    transform: translateY(-2px);
}

.project-meta {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    flex-wrap: wrap;
}

.project-category {
    font-size: 0.8125rem;
    color: var(--color-text-muted);
    background: var(--color-bg);
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--radius-full);
    border: 1px solid var(--color-border);
}

.project-status {
    font-size: 0.8125rem;
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--radius-full);
    font-weight: 500;
}

.project-status.paused {
    color: #f59e0b;
    background: rgba(245, 158, 11, 0.1);
    border: 1px solid rgba(245, 158, 11, 0.2);
}

.project-status.active {
    color: #10b981;
    background: rgba(16, 185, 129, 0.1);
    border: 1px solid rgba(16, 185, 129, 0.2);
}

.project-status.roadmap {
    color: #3b82f6;
    background: rgba(59, 130, 246, 0.1);
    border: 1px solid rgba(59, 130, 246, 0.2);
}

.project-body {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

.project-description {
    font-size: 0.9375rem;
    color: var(--color-text-secondary);
    line-height: 1.7;
    margin: 0;
}

.project-tech-stack {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
}

.tech-tag {
    font-size: 0.75rem;
    font-weight: 500;
    color: var(--color-primary);
    background: rgba(255, 107, 53, 0.1);
    padding: 6px 14px;
    border-radius: var(--radius-full);
    border: 1px solid rgba(255, 107, 53, 0.2);
    transition: all var(--transition-base);
}

.tech-tag:hover {
    background: rgba(255, 107, 53, 0.2);
    border-color: var(--color-primary);
    transform: translateY(-2px);
    box-shadow: 0 2px 8px rgba(255, 107, 53, 0.2);
}

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

.project-status-detail {
    font-size: 0.875rem;
    color: var(--color-text-muted);
    line-height: 1.6;
    margin: 0;
    font-style: italic;
}

/* Responsive layout for smaller screens */
@media (max-width: 768px) {
    .project-card-inner {
        flex-direction: column;
    }
    
    .project-left {
        flex-direction: row;
        border-right: none;
        border-bottom: 1px solid var(--color-border);
        padding-right: 0;
        padding-bottom: var(--spacing-lg);
        min-width: auto;
    }
    
    .project-title {
        font-size: 1.375rem;
    }
}

.equation {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.eq-label {
    font-size: 0.8125rem;
    color: var(--color-text-muted);
    min-width: 100px;
}

.equation .katex-eq,
.kinematic-equations .katex-eq {
    font-size: 0.95rem;
    color: var(--color-text);
}

.kinematic-equations .katex-eq {
    display: block;
    margin-bottom: var(--spacing-xs);
}

.kinematic-diagram {
    display: flex;
    align-items: center;
    gap: var(--spacing-xl);
    background: var(--color-bg);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    border: 1px solid var(--color-border);
}

.robot-diagram {
    position: relative;
    width: 120px;
    height: 80px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.robot-body {
    width: 60px;
    height: 40px;
    background: var(--color-surface);
    border: 2px solid var(--color-primary);
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
}

.coord-label {
    font-family: var(--font-mono);
    font-size: 0.875rem;
    color: var(--color-primary);
}

.wheel {
    position: absolute;
    width: 12px;
    height: 24px;
    background: var(--color-text-muted);
    border-radius: var(--radius-sm);
}

.wheel.left { left: 10px; }
.wheel.right { right: 10px; }

.velocity-vector {
    position: absolute;
    top: -10px;
    right: 20px;
    font-family: var(--font-mono);
    font-size: 0.875rem;
    color: var(--color-success);
}

.velocity-vector::before {
    content: '→';
    margin-right: 4px;
}

.kinematic-equations {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

.kinematic-equations code {
    font-family: var(--font-mono);
    font-size: 0.8125rem;
    color: var(--color-text-secondary);
}

/* ===== SKILLS SECTION ===== */
.skills {
    padding: var(--spacing-4xl) 0;
}

.skills-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-3xl);
}

.skill-category {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
    padding: var(--spacing-xl);
    opacity: 0;
    transform: translateY(30px);
    transition: all var(--transition-slow);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.4);
}

.skill-category:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.5), 0 0 0 1px var(--color-border-light);
    border-color: var(--color-border-light);
}

.skill-category.visible {
    opacity: 1;
    transform: translateY(0);
}

.skill-category:nth-child(2).visible {
    transition-delay: 100ms;
}

.skill-category:nth-child(3).visible {
    transition-delay: 200ms;
}

.skill-icon {
    width: 56px;
    height: 56px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-lg);
    margin-bottom: var(--spacing-lg);
}

.skill-icon.software {
    background: rgba(255, 107, 53, 0.1);
    color: var(--color-primary);
}

.skill-icon.hardware {
    background: rgba(255, 107, 53, 0.1);
    color: var(--color-primary);
}

.skill-icon.theory {
    background: rgba(255, 107, 53, 0.1);
    color: var(--color-primary);
}

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

.skill-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.skill-list li {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

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

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

.skill-progress {
    height: 100%;
    width: var(--progress);
    background: linear-gradient(90deg, var(--color-primary) 0%, var(--color-accent) 100%);
    border-radius: var(--radius-full);
    transition: width 1s ease-out;
}

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

.tools-section h4 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-lg);
}

.tools-grid {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: var(--spacing-sm);
}

.tool-tag {
    font-size: 0.8125rem;
    font-weight: 500;
    color: var(--color-text-secondary);
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-full);
    transition: all var(--transition-fast);
}

.tool-tag:hover {
    border-color: var(--color-primary);
    color: var(--color-primary);
}

/* ===== JOURNEY SECTION ===== */
.journey {
    padding: var(--spacing-4xl) 0;
    background: var(--color-bg-secondary);
}

/* Timeline Section */
.timeline-section {
    margin-bottom: var(--spacing-3xl);
}

.timeline-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-xs);
    color: var(--color-text);
}

.timeline-subtitle {
    font-size: 0.9375rem;
    color: var(--color-text-muted);
    margin-bottom: var(--spacing-xl);
}

.timeline {
    position: relative;
    padding-left: var(--spacing-2xl);
}

.timeline::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 2px;
    background: linear-gradient(180deg, var(--color-primary) 0%, var(--color-accent) 100%);
    border-radius: 2px;
}

.timeline-item {
    position: relative;
    padding-bottom: var(--spacing-xl);
    display: grid;
    grid-template-columns: 120px 1fr;
    gap: var(--spacing-lg);
}

.timeline-item:last-child {
    padding-bottom: 0;
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: calc(-1 * var(--spacing-2xl) - 5px);
    top: 22px;
    width: 12px;
    height: 12px;
    background: var(--color-bg-secondary);
    border: 2px solid var(--color-primary);
    border-radius: 50%;
}

.timeline-date {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--color-primary);
    font-family: var(--font-mono);
    padding-top: 18px;
}

.timeline-content {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
}

.timeline-badge {
    display: inline-block;
    font-size: 0.6875rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-success);
    background: rgba(34, 197, 94, 0.1);
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius-full);
    margin-bottom: var(--spacing-sm);
}

.timeline-content h4 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
}

.timeline-focus {
    font-size: 0.875rem;
    color: var(--color-text-secondary);
}

/* Experience Section */
.experience-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-lg);
}

.experience-card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
    padding: var(--spacing-xl);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
    transition: all var(--transition-base);
}

.experience-card:hover {
    border-color: var(--color-border-light);
    transform: translateY(-4px);
}

.experience-card.highlight {
    border-color: var(--color-accent);
    background: linear-gradient(135deg, rgba(139, 92, 246, 0.05) 0%, transparent 100%);
}

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

.experience-company {
    font-size: 0.8125rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-primary);
}

.experience-period {
    font-size: 0.75rem;
    color: var(--color-text-muted);
    font-family: var(--font-mono);
}

.experience-card h4 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--color-text);
}

.experience-context {
    font-size: 0.8125rem;
    color: var(--color-text-muted);
    font-style: italic;
}

.experience-card > p:not(.experience-context) {
    font-size: 0.875rem;
    color: var(--color-text-secondary);
    line-height: 1.6;
    flex: 1;
}

.experience-link {
    display: flex;
    align-items: flex-start;
    gap: var(--spacing-sm);
    font-size: 0.8125rem;
    color: var(--color-text-muted);
    padding: var(--spacing-sm);
    background: var(--color-bg);
    border-radius: var(--radius-md);
    margin-top: var(--spacing-sm);
}

.experience-link svg {
    flex-shrink: 0;
    color: var(--color-accent);
    transform: rotate(180deg);
}

.experience-link.highlight {
    background: rgba(139, 92, 246, 0.1);
    color: var(--color-accent-light);
}

.experience-stack {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
    margin-top: var(--spacing-sm);
}

.experience-stack span {
    font-size: 0.6875rem;
    font-weight: 500;
    color: var(--color-text-muted);
    background: var(--color-bg);
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius-sm);
    border: 1px solid var(--color-border);
}

/* Values Title */
.values-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-xl);
    margin-top: var(--spacing-2xl);
    color: var(--color-text);
    text-align: center;
}

.journey-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-3xl);
}

.journey-card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
    padding: var(--spacing-2xl);
    display: flex;
    gap: var(--spacing-xl);
    opacity: 0;
    transform: translateY(30px);
    transition: all var(--transition-slow);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.4);
}

.journey-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.5), 0 0 0 1px var(--color-border-light);
}

.journey-card.visible {
    opacity: 1;
    transform: translateY(0);
}

.journey-card:nth-child(2).visible {
    transition-delay: 100ms;
}

.journey-icon {
    flex-shrink: 0;
    width: 80px;
    height: 80px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-xl);
}

.journey-card.sport .journey-icon {
    background: rgba(255, 107, 53, 0.1);
    color: var(--color-primary);
}

.journey-card.cuisine .journey-icon {
    background: rgba(255, 107, 53, 0.1);
    color: var(--color-primary);
}

.journey-card.hiking .journey-icon {
    background: rgba(255, 107, 53, 0.1);
    color: var(--color-primary);
}

.journey-card.photography .journey-icon {
    background: rgba(255, 107, 53, 0.1);
    color: var(--color-primary);
}

.journey-content h3 {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: var(--spacing-xs);
}

.journey-subtitle {
    display: inline-block;
    font-size: 0.8125rem;
    font-weight: 600;
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: var(--spacing-md);
}

.journey-content > p {
    font-size: 0.9375rem;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-lg);
}

.journey-values {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.journey-values li {
    display: flex;
    flex-direction: column;
}

.journey-values strong {
    font-size: 0.9375rem;
    color: var(--color-text);
}

.journey-values span {
    font-size: 0.875rem;
    color: var(--color-text-muted);
}

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

.quote-block blockquote {
    position: relative;
    padding: var(--spacing-xl);
}

.quote-block p {
    font-size: 1.25rem;
    font-style: italic;
    color: var(--color-text-secondary);
    line-height: 1.8;
}

.quote-block::before,
.quote-block::after {
    content: '"';
    font-size: 4rem;
    font-family: Georgia, serif;
    color: var(--color-border);
    line-height: 1;
}

.quote-block::before {
    position: absolute;
    top: 0;
}

/* ===== CONTACT SECTION ===== */
.contact {
    padding: var(--spacing-4xl) 0;
}

.contact-content {
    max-width: 600px;
    margin: 0 auto;
}

.contact-links {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-2xl);
}

.contact-card {
    display: flex;
    align-items: center;
    gap: var(--spacing-lg);
    padding: var(--spacing-xl);
    background: #2f343a;
    border: 1px solid #3b4148;
    border-radius: var(--radius-xl);
    transition: all var(--transition-slow);
    opacity: 0;
    transform: translateY(20px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
}

.contact-card.visible {
    opacity: 1;
    transform: translateY(0);
}

.contact-card:nth-child(2).visible { transition-delay: 100ms; }
.contact-card:nth-child(3).visible { transition-delay: 200ms; }

.contact-card:hover {
    border-color: var(--color-primary);
    transform: translateY(-4px);
    box-shadow: 0 8px 24px rgba(255, 107, 53, 0.15), 0 0 0 1px var(--color-primary);
}

.contact-icon {
    flex-shrink: 0;
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-lg);
}

.contact-card.linkedin .contact-icon {
    background: rgba(0, 119, 181, 0.1);
    color: #0077b5;
}

.contact-card.github .contact-icon {
    background: rgba(255, 255, 255, 0.1);
    color: var(--color-text);
}

.contact-card.email .contact-icon {
    background: rgba(255, 107, 53, 0.1);
    color: var(--color-primary);
}

.contact-info {
    flex: 1;
    display: flex;
    flex-direction: column;
}

.contact-label {
    font-size: 1rem;
    font-weight: 600;
}

.contact-value {
    font-size: 0.875rem;
    color: var(--color-text-muted);
}

.contact-arrow {
    color: var(--color-text-muted);
    transition: transform var(--transition-fast);
}

.contact-card:hover .contact-arrow {
    transform: translate(4px, -4px);
    color: var(--color-primary);
}

.contact-cta {
    text-align: center;
    padding: var(--spacing-xl);
    background: linear-gradient(135deg, rgba(255, 107, 53, 0.08) 0%, rgba(255, 140, 97, 0.08) 100%);
    border-radius: var(--radius-xl);
    border: 1px solid var(--color-border);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
}

.contact-cta p {
    font-size: 1rem;
    color: var(--color-text-secondary);
}

/* ===== FOOTER ===== */
.footer {
    padding: var(--spacing-xl) 0;
    background: var(--color-bg-secondary);
    border-top: 1px solid var(--color-border);
}

.footer-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: var(--spacing-md);
}

.footer-brand {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-weight: 600;
}

.footer-logo {
    width: 24px;
    height: 24px;
    border-radius: var(--radius-sm);
}

.footer-copyright {
    font-size: 0.875rem;
    color: var(--color-text-muted);
}

/* ===== RESPONSIVE ===== */
@media (max-width: 1024px) {
    .hero-container {
        grid-template-columns: 1fr;
        gap: var(--spacing-2xl);
        text-align: center;
    }
    
    .hero-content {
        order: 2;
    }
    
    .hero-visual {
        order: 1;
    }
    
    .hero-tagline {
        border-left: none;
        padding-left: 0;
        border-bottom: 3px solid var(--color-primary);
        padding-bottom: var(--spacing-md);
        display: inline-block;
    }
    
    .hero-cta {
        justify-content: center;
    }
    
    .hero-image-wrapper {
        max-width: 300px;
    }
    
    .project-content {
        grid-template-columns: 1fr;
    }
    
    .skills-grid {
        grid-template-columns: 1fr;
    }
    
    .journey-grid {
        grid-template-columns: 1fr;
    }
    
    .experience-grid {
        grid-template-columns: 1fr 1fr;
    }
}

@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: var(--navbar-height);
        left: 0;
        right: 0;
        background: var(--color-bg);
        border-bottom: 1px solid var(--color-border);
        flex-direction: column;
        padding: var(--spacing-lg);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: all var(--transition-base);
    }
    
    .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }
    
    .nav-toggle {
        display: flex;
    }
    
    .project-header {
        flex-direction: column;
        align-items: flex-start;
        text-align: left;
    }
    
    .project-number {
        font-size: 2rem;
    }
    
    .project-images {
        grid-template-columns: 1fr;
    }
    
    .project-img.main {
        grid-column: span 1;
    }
    
    .architecture-diagram {
        flex-direction: column;
    }
    
    .arch-arrow {
        transform: rotate(90deg);
    }
    
    .journey-card {
        flex-direction: column;
        text-align: center;
    }
    
    .journey-icon {
        margin: 0 auto;
    }
    
    .kinematic-diagram {
        flex-direction: column;
    }
    
    .footer-content {
        flex-direction: column;
        text-align: center;
    }
    
    /* Timeline responsive */
    .timeline-item {
        grid-template-columns: 1fr;
        gap: var(--spacing-sm);
    }
    
    .timeline-date {
        padding-left: var(--spacing-md);
    }
    
    /* Experience responsive */
    .experience-grid {
        grid-template-columns: 1fr;
    }
    
    .experience-header {
        flex-direction: column;
        align-items: flex-start;
        gap: var(--spacing-xs);
    }
}

@media (max-width: 480px) {
    :root {
        --spacing-lg: 1rem;
        --spacing-xl: 1.5rem;
        --spacing-2xl: 2rem;
        --spacing-3xl: 3rem;
        --spacing-4xl: 4rem;
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .section-title {
        font-size: 1.75rem;
    }
    
    .btn {
        width: 100%;
    }
    
    .hero-cta {
        flex-direction: column;
    }
    
    .contact-card {
        flex-direction: column;
        text-align: center;
    }
    
    .contact-arrow {
        display: none;
    }
}

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

.hero-content > * {
    animation: fadeInUp 0.6s ease-out forwards;
    opacity: 0;
}

.hero-subtitle { animation-delay: 0.1s; }
.hero-title { animation-delay: 0.2s; }
.hero-tagline { animation-delay: 0.3s; }
.hero-description { animation-delay: 0.4s; }
.hero-cta { animation-delay: 0.5s; }

.hero-visual {
    animation: fadeInUp 0.8s ease-out 0.3s forwards;
    opacity: 0;
}

/* Skill progress animation */
.skill-category.visible .skill-progress {
    animation: progressFill 1s ease-out forwards;
}

@keyframes progressFill {
    from { width: 0; }
    to { width: var(--progress); }
}