/* =============================================================================
   DESIGN SYSTEM - Professional Portfolio
   Pure CSS - No Build Tools Required
   ============================================================================= */

/* =============================================================================
   CSS CUSTOM PROPERTIES (Design Tokens)
   ============================================================================= */

:root {
    /* Color Palette - Light Mode */
    --color-slate-950: #0f172a;
    --color-slate-900: #1e293b;
    --color-slate-800: #334155;
    --color-slate-700: #475569;
    --color-slate-600: #64748b;
    --color-slate-500: #94a3b8;
    --color-slate-400: #cbd5e1;
    --color-slate-300: #e2e8f0;
    --color-slate-200: #f1f5f9;
    --color-slate-100: #f8fafc;
    --color-slate-50: #ffffff;

    /* Accent - Muted Teal */
    --color-accent-700: #0f766e;
    --color-accent-600: #0d9488;
    --color-accent-500: #14b8a6;
    --color-accent-400: #2dd4bf;
    --color-accent-300: #5eead4;
    --color-accent-100: #ccfbf1;
    --color-accent-50: #f0fdfa;

    /* Semantic Colors */
    --color-bg-primary: var(--color-slate-50);
    --color-bg-secondary: var(--color-slate-200);
    --color-bg-tertiary: var(--color-slate-100);
    --color-bg-card: var(--color-slate-50);
    --color-bg-card-hover: var(--color-slate-100);

    --color-text-primary: var(--color-slate-900);
    --color-text-secondary: var(--color-slate-700);
    --color-text-muted: var(--color-slate-600);
    --color-text-accent: var(--color-accent-600);

    --color-border: var(--color-slate-300);
    --color-border-light: var(--color-slate-200);

    /* Typography */
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', 'Consolas', monospace;

    --text-xs: 0.75rem;
    --text-sm: 0.875rem;
    --text-base: 1rem;
    --text-lg: 1.125rem;
    --text-xl: 1.25rem;
    --text-2xl: 1.5rem;
    --text-3xl: 1.875rem;
    --text-4xl: 2.25rem;
    --text-5xl: 3rem;
    --text-6xl: 3.75rem;

    --font-normal: 400;
    --font-medium: 500;
    --font-semibold: 600;
    --font-bold: 700;

    --leading-tight: 1.25;
    --leading-normal: 1.5;
    --leading-relaxed: 1.625;

    --tracking-tight: -0.025em;
    --tracking-normal: 0;
    --tracking-wide: 0.025em;

    /* 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: 1200px;
    --container-padding: 1.5rem;
    --section-gap: 7rem;

    /* Borders */
    --radius-sm: 0.25rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-full: 9999px;

    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);

    /* Motion */
    --duration-fast: 150ms;
    --duration-normal: 250ms;
    --duration-slow: 400ms;
    --duration-slower: 600ms;

    --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
    --ease-in-out: cubic-bezier(0.65, 0, 0.35, 1);

    /* Z-index */
    --z-base: 0;
    --z-dropdown: 100;
    --z-sticky: 200;
    --z-fixed: 300;
    --z-modal: 400;
}

/* Dark Mode */
[data-theme="dark"] {
    --color-bg-primary: #0a0f1a;
    --color-bg-secondary: #0f1629;
    --color-bg-tertiary: #1a2332;
    --color-bg-card: #111827;
    --color-bg-card-hover: #1f2937;

    --color-text-primary: #f1f5f9;
    --color-text-secondary: #cbd5e1;
    --color-text-muted: #94a3b8;
    --color-text-accent: var(--color-accent-400);

    --color-border: #1f2937;
    --color-border-light: #374151;
}

/* =============================================================================
   BASE STYLES
   ============================================================================= */

*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
    scroll-padding-top: 5rem;
}

body {
    font-family: var(--font-sans);
    font-size: var(--text-base);
    font-weight: var(--font-normal);
    line-height: var(--leading-relaxed);
    color: var(--color-text-primary);
    background-color: var(--color-bg-primary);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    transition: background-color var(--duration-normal) var(--ease-out),
        color var(--duration-normal) var(--ease-out);
}

h1,
h2,
h3,
h4,
h5,
h6 {
    font-weight: var(--font-semibold);
    line-height: var(--leading-tight);
    letter-spacing: var(--tracking-tight);
    color: var(--color-text-primary);
}

p {
    color: var(--color-text-secondary);
    line-height: var(--leading-relaxed);
}

a {
    color: var(--color-text-accent);
    text-decoration: none;
    transition: color var(--duration-fast) var(--ease-out);
}

a:hover {
    color: var(--color-accent-500);
}

ul {
    list-style: none;
}

:focus-visible {
    outline: 2px solid var(--color-accent-500);
    outline-offset: 2px;
}

::selection {
    background-color: var(--color-accent-100);
    color: var(--color-accent-700);
}

[data-theme="dark"] ::selection {
    background-color: var(--color-accent-700);
    color: var(--color-accent-100);
}

/* =============================================================================
   LAYOUT
   ============================================================================= */

.container {
    width: 100%;
    max-width: var(--container-max);
    margin-left: auto;
    margin-right: auto;
    padding-left: var(--container-padding);
    padding-right: var(--container-padding);
}

.section {
    padding-top: var(--section-gap);
    padding-bottom: var(--section-gap);
    position: relative;
    z-index: 1;
}

/* =============================================================================
   INTERACTIVE BACKGROUND
   ============================================================================= */

#particles-canvas {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 0;
    opacity: 0.7;
}

/* =============================================================================
   HEADER
   ============================================================================= */

.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: var(--z-fixed);
    background-color: transparent;
    transition: all var(--duration-normal) var(--ease-out);
}

.header.scrolled {
    background-color: rgba(248, 250, 252, 0.9);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--color-border-light);
}

[data-theme="dark"] .header.scrolled {
    background-color: rgba(10, 15, 26, 0.9);
}

.header-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    max-width: var(--container-max);
    margin: 0 auto;
    padding: var(--space-4) var(--container-padding);
}

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

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

.logo-dot {
    color: var(--color-accent-500);
}

.nav-list {
    display: flex;
    align-items: center;
    gap: var(--space-1);
}

.nav-link {
    display: block;
    padding: var(--space-2) var(--space-4);
    font-size: var(--text-sm);
    font-weight: var(--font-medium);
    color: var(--color-text-secondary);
    border-radius: var(--radius-md);
    transition: all var(--duration-fast) var(--ease-out);
}

.nav-link:hover {
    color: var(--color-text-primary);
    background-color: var(--color-bg-secondary);
}

.header-actions {
    display: flex;
    align-items: center;
    gap: var(--space-2);
}

.theme-toggle,
.menu-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background-color: transparent;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    color: var(--color-text-secondary);
    cursor: pointer;
    transition: all var(--duration-fast) var(--ease-out);
}

.theme-toggle:hover,
.menu-toggle:hover {
    background-color: var(--color-bg-secondary);
    color: var(--color-text-primary);
    border-color: var(--color-accent-500);
}

.icon-sun {
    display: block;
}

.icon-moon {
    display: none;
}

[data-theme="dark"] .icon-sun {
    display: none;
}

[data-theme="dark"] .icon-moon {
    display: block;
}

.menu-toggle {
    display: none;
}

.icon-close {
    display: none;
}

.nav.open .icon-menu {
    display: none;
}

.nav.open .icon-close {
    display: block;
}

/* =============================================================================
   BUTTONS
   ============================================================================= */

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-2);
    font-family: var(--font-sans);
    font-weight: var(--font-medium);
    text-decoration: none;
    border: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--duration-fast) var(--ease-out);
}

.btn-lg {
    font-size: var(--text-lg);
    padding: var(--space-4) var(--space-8);
}

.btn-primary {
    background-color: var(--color-accent-600);
    color: white;
}

.btn-primary:hover {
    background-color: var(--color-accent-500);
    color: white;
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

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

.btn-secondary:hover {
    background-color: var(--color-bg-tertiary);
    border-color: var(--color-accent-500);
}

/* =============================================================================
   BADGES
   ============================================================================= */

.badge {
    display: inline-flex;
    align-items: center;
    padding: var(--space-1) var(--space-3);
    font-size: var(--text-xs);
    font-weight: var(--font-medium);
    border-radius: var(--radius-full);
    transition: all var(--duration-fast) var(--ease-out);
    background-color: var(--color-bg-secondary);
    color: var(--color-text-secondary);
}

.badge-accent {
    background-color: var(--color-accent-100);
    color: var(--color-accent-700);
}

[data-theme="dark"] .badge-accent {
    background-color: rgba(20, 184, 166, 0.15);
    color: var(--color-accent-400);
}

.badge-outline {
    background-color: transparent;
    border: 1px solid var(--color-border);
    color: var(--color-text-muted);
}

/* =============================================================================
   SECTION HEADING
   ============================================================================= */

.section-heading {
    margin-bottom: var(--space-12);
}

.section-overline {
    display: inline-block;
    font-size: var(--text-sm);
    font-weight: var(--font-medium);
    color: var(--color-text-accent);
    text-transform: uppercase;
    letter-spacing: var(--tracking-wide);
    margin-bottom: var(--space-2);
}

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

.section-description {
    font-size: var(--text-lg);
    color: var(--color-text-muted);
    max-width: 600px;
}

/* =============================================================================
   HERO SECTION
   ============================================================================= */

.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    position: relative;
    padding-top: var(--space-24);
    padding-bottom: var(--space-16);
    overflow: hidden;
}

.hero-content {
    position: relative;
    z-index: 1;
    max-width: 800px;
}

.hero-intro {
    margin-bottom: var(--space-8);
}

.hero-greeting {
    display: block;
    font-size: var(--text-sm);
    font-weight: var(--font-medium);
    color: var(--color-text-accent);
    text-transform: uppercase;
    letter-spacing: var(--tracking-wide);
    margin-bottom: var(--space-3);
    opacity: 0;
    animation: fadeSlideUp var(--duration-slow) var(--ease-out) forwards;
}

.hero-name {
    font-size: var(--text-6xl);
    font-weight: var(--font-bold);
    line-height: 1.1;
    margin-bottom: var(--space-4);
    opacity: 0;
    animation: fadeSlideUp var(--duration-slow) var(--ease-out) 100ms forwards;
    background: linear-gradient(135deg, var(--color-text-primary) 0%, var(--color-accent-500) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-role {
    font-size: var(--text-xl);
    font-weight: var(--font-medium);
    color: var(--color-text-muted);
    opacity: 0;
    animation: fadeSlideUp var(--duration-slow) var(--ease-out) 200ms forwards;
}

.hero-value {
    margin-bottom: var(--space-10);
    opacity: 0;
    animation: fadeSlideUp var(--duration-slow) var(--ease-out) 300ms forwards;
}

.hero-tagline {
    font-size: var(--text-2xl);
    color: var(--color-text-secondary);
    line-height: var(--leading-relaxed);
    margin-bottom: var(--space-2);
}

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

.hero-stats {
    display: flex;
    gap: var(--space-12);
    margin-bottom: var(--space-10);
    padding: var(--space-6) 0;
    border-top: 1px solid var(--color-border);
    border-bottom: 1px solid var(--color-border);
    opacity: 0;
    animation: fadeSlideUp var(--duration-slow) var(--ease-out) 400ms forwards;
}

.stat {
    display: flex;
    flex-direction: column;
    gap: var(--space-1);
}

.stat-value {
    font-size: var(--text-3xl);
    font-weight: var(--font-bold);
    color: var(--color-text-accent);
    font-family: var(--font-mono);
}

.stat-label {
    font-size: var(--text-sm);
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: var(--tracking-wide);
}

.hero-actions {
    display: flex;
    gap: var(--space-4);
    opacity: 0;
    animation: fadeSlideUp var(--duration-slow) var(--ease-out) 500ms forwards;
}

/* Scroll Indicator */
.scroll-indicator {
    position: absolute;
    bottom: var(--space-8);
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-3);
    opacity: 0;
    animation: fadeIn 1s ease-out 1.5s forwards;
}

.scroll-mouse {
    width: 24px;
    height: 40px;
    border: 2px solid var(--color-border);
    border-radius: 12px;
    position: relative;
}

.scroll-wheel {
    width: 4px;
    height: 8px;
    background-color: var(--color-accent-500);
    border-radius: 2px;
    position: absolute;
    top: 8px;
    left: 50%;
    transform: translateX(-50%);
    animation: scrollBounce 2s ease-in-out infinite;
}

.scroll-text {
    font-size: var(--text-xs);
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: var(--tracking-wide);
}

/* =============================================================================
   ABOUT SECTION
   ============================================================================= */

.about {
    background-color: var(--color-bg-secondary);
}

.about-content {
    display: grid;
    grid-template-columns: 1.2fr 1fr;
    gap: var(--space-12);
    align-items: start;
}

.about-narrative {
    display: flex;
    flex-direction: column;
    gap: var(--space-6);
}

.about-narrative p {
    font-size: var(--text-lg);
    line-height: var(--leading-relaxed);
}

.about-education {
    position: sticky;
    top: calc(72px + var(--space-8));
}

.edu-card {
    background-color: var(--color-bg-card);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
    padding: var(--space-6);
    transition: all var(--duration-normal) var(--ease-out);
}

.edu-card:hover {
    border-color: var(--color-accent-500);
    box-shadow: var(--shadow-lg);
    transform: translateY(-4px);
}

.edu-header {
    display: flex;
    gap: var(--space-4);
    margin-bottom: var(--space-4);
}

.edu-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, var(--color-accent-100) 0%, var(--color-accent-50) 100%);
    color: var(--color-accent-600);
    border-radius: var(--radius-lg);
    flex-shrink: 0;
}

[data-theme="dark"] .edu-icon {
    background: linear-gradient(135deg, rgba(20, 184, 166, 0.2) 0%, rgba(20, 184, 166, 0.1) 100%);
    color: var(--color-accent-400);
}

.edu-degree {
    font-size: var(--text-lg);
    font-weight: var(--font-semibold);
    margin-bottom: var(--space-1);
}

.edu-institution {
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
}

.edu-meta {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    margin-bottom: var(--space-3);
}

.edu-gpa {
    background: linear-gradient(135deg, var(--color-accent-600) 0%, var(--color-accent-500) 100%);
    padding: var(--space-1) var(--space-3);
    border-radius: var(--radius-full);
    font-size: var(--text-sm);
    font-weight: var(--font-semibold);
    color: white;
    font-family: var(--font-mono);
}

.edu-period {
    font-size: var(--text-xs);
    color: var(--color-text-muted);
}

.edu-note {
    font-size: var(--text-sm);
    font-weight: var(--font-medium);
    color: var(--color-text-accent);
    margin-bottom: var(--space-4);
    padding: var(--space-2) var(--space-3);
    background-color: var(--color-bg-secondary);
    border-radius: var(--radius-md);
    display: inline-block;
}

.edu-highlights {
    border-top: 1px solid var(--color-border-light);
    padding-top: var(--space-4);
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
}

.edu-highlights li {
    display: flex;
    align-items: flex-start;
    gap: var(--space-2);
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
}

.highlight-icon {
    color: var(--color-accent-500);
    flex-shrink: 0;
}

/* =============================================================================
   EXPERIENCE SECTION
   ============================================================================= */

.timeline {
    display: flex;
    flex-direction: column;
}

.timeline-item {
    display: flex;
    gap: var(--space-8);
}

.timeline-marker {
    display: flex;
    flex-direction: column;
    align-items: center;
    flex-shrink: 0;
    width: 24px;
}

.timeline-dot {
    width: 14px;
    height: 14px;
    background: linear-gradient(135deg, var(--color-accent-500) 0%, var(--color-accent-600) 100%);
    border-radius: 50%;
    flex-shrink: 0;
    margin-top: var(--space-6);
    box-shadow: 0 0 0 4px var(--color-bg-primary), 0 0 0 6px var(--color-accent-100);
}

[data-theme="dark"] .timeline-dot {
    box-shadow: 0 0 0 4px var(--color-bg-primary), 0 0 0 6px rgba(20, 184, 166, 0.2);
}

.timeline-line {
    width: 2px;
    flex: 1;
    background: linear-gradient(180deg, var(--color-accent-500) 0%, var(--color-border) 30%);
    margin-top: var(--space-4);
}

.timeline-card {
    flex: 1;
    background-color: var(--color-bg-card);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
    margin-bottom: var(--space-6);
    transition: all var(--duration-normal) var(--ease-out);
    overflow: hidden;
}

.timeline-card:hover {
    border-color: var(--color-accent-500);
    box-shadow: var(--shadow-lg);
    transform: translateX(8px);
}

.card-header {
    padding: var(--space-6);
    background: linear-gradient(135deg, var(--color-bg-tertiary) 0%, var(--color-bg-card) 100%);
    border-bottom: 1px solid var(--color-border-light);
}

.card-meta {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    margin-bottom: var(--space-3);
}

.card-period {
    font-size: var(--text-sm);
    font-weight: var(--font-semibold);
    color: var(--color-text-accent);
    font-family: var(--font-mono);
}

.card-role {
    font-size: var(--text-xl);
    font-weight: var(--font-bold);
    margin-bottom: var(--space-1);
}

.card-company {
    font-size: var(--text-base);
    font-weight: var(--font-medium);
    color: var(--color-text-secondary);
}

.card-location {
    font-size: var(--text-sm);
    color: var(--color-text-muted);
}

.card-body {
    padding: var(--space-6);
}

.achievements {
    margin-bottom: var(--space-6);
    display: flex;
    flex-direction: column;
    gap: var(--space-3);
}

.achievements li {
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
    padding-left: var(--space-6);
    position: relative;
    line-height: var(--leading-relaxed);
}

.achievements li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 8px;
    width: 6px;
    height: 6px;
    background: linear-gradient(135deg, var(--color-accent-500) 0%, var(--color-accent-400) 100%);
    border-radius: 2px;
}

.card-technologies {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-2);
}

/* =============================================================================
   PROJECTS SECTION
   ============================================================================= */

.projects {
    background-color: var(--color-bg-secondary);
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-6);
}

.project-card {
    background-color: var(--color-bg-card);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
    display: flex;
    flex-direction: column;
    transition: all var(--duration-normal) var(--ease-out);
    position: relative;
    overflow: hidden;
}

.project-glow {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, transparent 0%, var(--color-accent-500) 50%, transparent 100%);
    opacity: 0;
    transition: opacity var(--duration-normal) var(--ease-out);
}

.project-card:hover {
    border-color: var(--color-accent-500);
    box-shadow: var(--shadow-xl);
    transform: translateY(-8px);
}

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

.project-header {
    padding: var(--space-6);
    border-bottom: 1px solid var(--color-border-light);
}

.project-category-wrapper {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    margin-bottom: var(--space-3);
}

.project-category {
    font-size: var(--text-xs);
    font-weight: var(--font-semibold);
    color: var(--color-text-accent);
    text-transform: uppercase;
    letter-spacing: var(--tracking-wide);
    background: linear-gradient(135deg, var(--color-accent-100) 0%, transparent 100%);
    padding: var(--space-1) var(--space-3);
    border-radius: var(--radius-full);
}

[data-theme="dark"] .project-category {
    background: linear-gradient(135deg, rgba(20, 184, 166, 0.2) 0%, transparent 100%);
}

.project-period {
    font-size: var(--text-xs);
    color: var(--color-text-muted);
    font-family: var(--font-mono);
}

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

.project-description {
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
    line-height: var(--leading-relaxed);
}

.project-body {
    padding: var(--space-6);
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: var(--space-6);
}

.project-section {
    display: flex;
    flex-direction: column;
    gap: var(--space-3);
}

.project-section-title {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    font-size: var(--text-xs);
    font-weight: var(--font-semibold);
    color: var(--color-text-accent);
    text-transform: uppercase;
    letter-spacing: var(--tracking-wide);
}

.project-architecture {
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
    line-height: var(--leading-relaxed);
    font-family: var(--font-mono);
    background-color: var(--color-bg-secondary);
    padding: var(--space-4);
    border-radius: var(--radius-md);
    border-left: 3px solid var(--color-accent-500);
}

.project-impact {
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
}

.project-impact li {
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
}

.project-footer {
    padding: var(--space-4) var(--space-6);
    background: linear-gradient(180deg, var(--color-bg-tertiary) 0%, var(--color-bg-secondary) 100%);
    border-top: 1px solid var(--color-border-light);
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-2);
}

/* =============================================================================
   SKILLS SECTION
   ============================================================================= */

.skills-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-6);
}

.skill-category {
    background-color: var(--color-bg-card);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
    padding: var(--space-6);
    transition: all var(--duration-normal) var(--ease-out);
    position: relative;
    overflow: hidden;
}

.skill-category::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--color-accent-600) 0%, var(--color-accent-400) 100%);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform var(--duration-normal) var(--ease-out);
}

.skill-category:hover {
    border-color: var(--color-accent-500);
    box-shadow: var(--shadow-md);
    transform: translateY(-4px);
}

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

.skill-category-title {
    font-size: var(--text-sm);
    font-weight: var(--font-bold);
    color: var(--color-text-accent);
    text-transform: uppercase;
    letter-spacing: var(--tracking-wide);
    margin-bottom: var(--space-4);
    padding-bottom: var(--space-3);
    border-bottom: 1px solid var(--color-border-light);
}

.skill-list {
    display: flex;
    flex-direction: column;
    gap: var(--space-3);
}

.skill-item {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
    transition: transform var(--duration-fast) var(--ease-out);
}

.skill-category:hover .skill-item {
    transform: translateX(4px);
}

.skill-indicator {
    width: 8px;
    height: 8px;
    background: linear-gradient(135deg, var(--color-accent-500) 0%, var(--color-accent-400) 100%);
    border-radius: 2px;
    flex-shrink: 0;
    transition: transform var(--duration-fast) var(--ease-out);
}

.skill-category:hover .skill-indicator {
    transform: scale(1.2);
}

/* =============================================================================
   CERTIFICATIONS SECTION
   ============================================================================= */

.certifications {
    background-color: var(--color-bg-secondary);
}

.credentials-content {
    display: grid;
    grid-template-columns: 1fr 1.5fr;
    gap: var(--space-12);
}

.credentials-title {
    font-size: var(--text-lg);
    font-weight: var(--font-bold);
    margin-bottom: var(--space-6);
}

.credentials-cards {
    display: flex;
    flex-direction: column;
    gap: var(--space-4);
}

.credential-card {
    background-color: var(--color-bg-card);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-xl);
    padding: var(--space-5);
    display: flex;
    gap: var(--space-4);
    transition: all var(--duration-normal) var(--ease-out);
    position: relative;
    overflow: hidden;
}

.credential-card::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 3px;
    background: linear-gradient(180deg, var(--color-accent-500) 0%, var(--color-accent-300) 100%);
    transform: scaleY(0);
    transform-origin: top;
    transition: transform var(--duration-normal) var(--ease-out);
}

.credential-card:hover {
    border-color: var(--color-accent-500);
    box-shadow: var(--shadow-md);
    transform: translateX(4px);
}

.credential-card:hover::before {
    transform: scaleY(1);
}

.credential-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, var(--color-accent-100) 0%, var(--color-accent-50) 100%);
    color: var(--color-accent-600);
    border-radius: var(--radius-lg);
    flex-shrink: 0;
}

[data-theme="dark"] .credential-icon {
    background: linear-gradient(135deg, rgba(20, 184, 166, 0.2) 0%, rgba(20, 184, 166, 0.1) 100%);
    color: var(--color-accent-400);
}

.credential-content {
    display: flex;
    flex-direction: column;
    gap: var(--space-1);
    flex: 1;
}

.credential-title {
    font-size: var(--text-base);
    font-weight: var(--font-bold);
}

.credential-issuer,
.credential-org {
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
}

.credential-id,
.credential-institution {
    font-size: var(--text-xs);
    color: var(--color-text-muted);
    font-family: var(--font-mono);
}

.credential-year,
.credential-period {
    font-size: var(--text-xs);
    font-weight: var(--font-semibold);
    color: var(--color-text-accent);
    font-family: var(--font-mono);
}

.credential-desc {
    font-size: var(--text-sm);
    color: var(--color-text-muted);
    margin-top: var(--space-2);
    line-height: var(--leading-relaxed);
}

/* =============================================================================
   CONTACT SECTION
   ============================================================================= */

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

.contact-content .section-overline {
    background: linear-gradient(135deg, var(--color-accent-100) 0%, transparent 100%);
    padding: var(--space-1) var(--space-4);
    border-radius: var(--radius-full);
}

[data-theme="dark"] .contact-content .section-overline {
    background: linear-gradient(135deg, rgba(20, 184, 166, 0.2) 0%, transparent 100%);
}

.contact-title {
    font-size: var(--text-4xl);
    font-weight: var(--font-bold);
    margin-bottom: var(--space-4);
    background: linear-gradient(135deg, var(--color-text-primary) 0%, var(--color-accent-500) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.contact-description {
    font-size: var(--text-lg);
    color: var(--color-text-secondary);
    line-height: var(--leading-relaxed);
    margin-bottom: var(--space-10);
}

.contact-actions {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-6);
}

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

.contact-link {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    font-size: var(--text-base);
    font-weight: var(--font-medium);
    color: var(--color-text-secondary);
    padding: var(--space-2) var(--space-4);
    border-radius: var(--radius-md);
    transition: all var(--duration-fast) var(--ease-out);
}

.contact-link:hover {
    color: var(--color-text-accent);
    background-color: var(--color-bg-secondary);
}

.contact-link svg {
    transition: transform var(--duration-fast) var(--ease-out);
}

.contact-link:hover svg {
    transform: translateY(-2px) scale(1.1);
}

/* =============================================================================
   FOOTER
   ============================================================================= */

.footer {
    padding: var(--space-8) 0;
    border-top: 1px solid var(--color-border);
    background-color: var(--color-bg-secondary);
    position: relative;
    z-index: 1;
}

.footer-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: var(--space-4);
}

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

.footer-links {
    display: flex;
    align-items: center;
    gap: var(--space-3);
}

.footer-links a {
    font-size: var(--text-sm);
    color: var(--color-text-secondary);
    transition: color var(--duration-fast) var(--ease-out);
}

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

.footer-separator {
    color: var(--color-text-muted);
    opacity: 0.5;
}

/* =============================================================================
   ANIMATIONS
   ============================================================================= */

@keyframes fadeSlideUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }

    to {
        opacity: 1;
    }
}

@keyframes scrollBounce {

    0%,
    100% {
        top: 8px;
        opacity: 1;
    }

    50% {
        top: 20px;
        opacity: 0.3;
    }
}

/* Scroll Reveal Animations */
.reveal-up,
.reveal-left {
    opacity: 0;
    transition: opacity 0.6s cubic-bezier(0.16, 1, 0.3, 1),
        transform 0.6s cubic-bezier(0.16, 1, 0.3, 1);
}

.reveal-up {
    transform: translateY(40px);
}

.reveal-left {
    transform: translateX(40px);
}

.reveal-up.visible,
.reveal-left.visible {
    opacity: 1;
    transform: translate(0, 0);
}

/* =============================================================================
   RESPONSIVE
   ============================================================================= */

@media (max-width: 900px) {

    .about-content,
    .credentials-content {
        grid-template-columns: 1fr;
        gap: var(--space-8);
    }

    .about-education {
        position: static;
    }

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

    .skills-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    :root {
        --text-5xl: 2.25rem;
        --text-4xl: 1.875rem;
        --text-3xl: 1.5rem;
        --text-6xl: 2.5rem;
        --section-gap: 4rem;
        --container-padding: 1rem;
    }

    .menu-toggle {
        display: flex;
    }

    .nav {
        position: fixed;
        top: 72px;
        left: 0;
        right: 0;
        bottom: 0;
        background-color: var(--color-bg-primary);
        padding: var(--space-6);
        transform: translateX(100%);
        transition: transform var(--duration-normal) var(--ease-out);
        z-index: var(--z-fixed);
    }

    .nav.open {
        transform: translateX(0);
    }

    .nav-list {
        flex-direction: column;
        align-items: stretch;
        gap: var(--space-2);
    }

    .nav-link {
        font-size: var(--text-lg);
        padding: var(--space-4);
    }

    .hero-stats {
        flex-wrap: wrap;
        gap: var(--space-6);
    }

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

    .scroll-indicator {
        display: none;
    }

    .timeline-item {
        gap: var(--space-4);
    }

    .timeline-marker {
        width: 16px;
    }

    .timeline-dot {
        width: 12px;
        height: 12px;
        margin-top: var(--space-5);
        box-shadow: 0 0 0 3px var(--color-bg-primary), 0 0 0 5px var(--color-accent-100);
    }

    .timeline-card:hover {
        transform: none;
    }
}

@media (max-width: 600px) {
    .skills-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    :root {
        --text-6xl: 2rem;
        --text-5xl: 1.75rem;
        --text-4xl: 1.5rem;
        --text-3xl: 1.25rem;
    }

    .hero-stats {
        gap: var(--space-4);
    }

    .stat {
        flex: 1;
        min-width: 100px;
    }

    .timeline-marker {
        display: none;
    }

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

    .footer-content {
        flex-direction: column;
        text-align: center;
    }
}