/* ==========================================================================
   Portfolio Styles - Elio Hanna
   Version: 2.1 - Enhanced with Accessibility & Performance Optimizations

   Table of Contents:
   1. CSS Custom Properties (Variables)
   2. Reset and Base Styles
   3. Accessibility Utilities
   4. Navigation
   5. Hero Section
   6. Section Styles
   7. About Section
   8. Experience Timeline
   9. Skills Section
   10. Education Section
   11. Contact Section
   12. Footer
   13. Back to Top Button
   14. Responsive Breakpoints
   15. Reduced Motion Support
   16. High Contrast Mode
   17. Print Styles
   ========================================================================== */

/* ==========================================================================
   1. CSS Custom Properties
   ========================================================================== */

:root {
    /* Primary Colors */
    --primary: #3b82f6;
    --primary-rgb: 59, 130, 246;
    --primary-dark: #2563eb;
    --primary-light: #60a5fa;

    /* Accent Colors */
    --accent: #06b6d4;
    --accent-rgb: 6, 182, 212;
    --accent-secondary: #8b5cf6;
    --accent-tertiary: #ec4899;

    /* Text Colors */
    --text: #1e293b;
    --text-rgb: 30, 41, 59;
    --text-light: #64748b;
    --text-lighter: #94a3b8;

    /* Background Colors */
    --bg: #ffffff;
    --bg-rgb: 255, 255, 255;
    --bg-alt: #f8fafc;
    --bg-card: #ffffff;
    --bg-elevated: #ffffff;

    /* Secondary/Dark Colors */
    --secondary: #1e293b;
    --secondary-rgb: 30, 41, 59;

    /* Border & Shadows */
    --border: #e2e8f0;
    --border-rgb: 226, 232, 240;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1);
    --shadow-glow: 0 0 40px rgba(var(--primary-rgb), 0.15);

    /* Glassmorphism */
    --glass-bg: rgba(255, 255, 255, 0.7);
    --glass-border: rgba(255, 255, 255, 0.3);
    --glass-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);

    /* Border Radius */
    --radius: 16px;
    --radius-sm: 8px;
    --radius-lg: 24px;
    --radius-xl: 32px;

    /* Focus Ring - Enhanced for accessibility */
    --focus-ring: 0 0 0 3px rgba(var(--primary-rgb), 0.5);
    --focus-ring-offset: 0 0 0 2px var(--bg);

    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 0.5s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-bounce: 0.5s cubic-bezier(0.68, -0.55, 0.265, 1.55);

    /* Spacing */
    --section-padding: 6rem 2rem;
    --container-max: 1200px;

    /* Header height */
    --header-height: 80px;
}

/* ==========================================================================
   Dark Mode Theme
   ========================================================================== */

[data-theme="dark"] {
    --primary: #60a5fa;
    --primary-rgb: 96, 165, 250;
    --primary-dark: #3b82f6;
    --primary-light: #93c5fd;

    --text: #f1f5f9;
    --text-rgb: 241, 245, 249;
    --text-light: #cbd5e1;
    --text-lighter: #94a3b8;

    --bg: #0f172a;
    --bg-rgb: 15, 23, 42;
    --bg-alt: #1e293b;
    --bg-card: #1e293b;
    --bg-elevated: #334155;

    --secondary: #0f172a;
    --secondary-rgb: 15, 23, 42;

    --border: #334155;
    --border-rgb: 51, 65, 85;

    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.3), 0 2px 4px -2px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.4), 0 4px 6px -4px rgba(0, 0, 0, 0.3);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.4), 0 8px 10px -6px rgba(0, 0, 0, 0.3);
    --shadow-glow: 0 0 60px rgba(var(--primary-rgb), 0.2);

    --glass-bg: rgba(30, 41, 59, 0.7);
    --glass-border: rgba(51, 65, 85, 0.5);
    --glass-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
}

/* ==========================================================================
   2. Reset and Base Styles
   ========================================================================== */

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

html {
    scroll-behavior: smooth;
    scroll-padding-top: var(--header-height);
    font-size: 100%; /* Respect user font-size preferences */
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: var(--text);
    background-color: var(--bg);
    transition: background-color var(--transition), color var(--transition);
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Smooth theme transition for all elements */
*,
*::before,
*::after {
    transition: background-color var(--transition), border-color var(--transition), box-shadow var(--transition);
}

/* Selection styling */
::selection {
    background: rgba(var(--primary-rgb), 0.2);
    color: var(--primary);
}

/* Improve text rendering */
h1, h2, h3, h4, h5, h6 {
    text-rendering: optimizeLegibility;
}

/* Remove default list styles where appropriate */
ul[role="list"],
ol[role="list"],
ul[role="menubar"] {
    list-style: none;
}

/* Ensure images are responsive */
img {
    max-width: 100%;
    height: auto;
    display: block;
}

/* ==========================================================================
   3. Accessibility Utilities
   ========================================================================== */

/* Skip Link for keyboard navigation */
.skip-link {
    position: absolute;
    top: -100%;
    left: 50%;
    transform: translateX(-50%);
    background: var(--primary);
    color: white;
    padding: 0.875rem 1.75rem;
    border-radius: var(--radius-sm);
    font-weight: 600;
    text-decoration: none;
    z-index: 10000;
    transition: top var(--transition-fast);
    box-shadow: var(--shadow-lg);
}

.skip-link:focus {
    top: 1rem;
    outline: none;
}

/* Visually hidden but accessible to screen readers */
.visually-hidden,
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* Focus styles for all interactive elements */
a:focus-visible,
button:focus-visible,
input:focus-visible,
textarea:focus-visible,
select:focus-visible,
[tabindex="0"]:focus-visible,
[role="button"]:focus-visible,
[role="link"]:focus-visible,
[role="menuitem"]:focus-visible {
    outline: 3px solid var(--primary);
    outline-offset: 2px;
    border-radius: var(--radius-sm);
}

/* Remove outline for mouse users, keep for keyboard */
:focus:not(:focus-visible) {
    outline: none;
}

/* Ensure focus is visible on dark backgrounds */
[data-theme="dark"] a:focus-visible,
[data-theme="dark"] button:focus-visible {
    outline-color: var(--primary-light);
}

/* ==========================================================================
   4. Navigation
   ========================================================================== */

header {
    position: fixed;
    top: 0;
    width: 100%;
    height: var(--header-height);
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--glass-border);
    z-index: 1000;
    transition: all var(--transition);
}

header.scrolled {
    background: var(--glass-bg);
    box-shadow: var(--glass-shadow);
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 1rem 2rem;
    height: 100%;
}

/* Logo with gradient animation */
.logo {
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, var(--primary), var(--accent), var(--accent-secondary));
    background-size: 200% 200%;
    animation: gradientShift 3s ease infinite;
    border-radius: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    color: white;
    font-size: 1.1rem;
    cursor: pointer;
    text-decoration: none;
    transition: transform var(--transition-bounce), box-shadow var(--transition);
    box-shadow: 0 4px 15px rgba(var(--primary-rgb), 0.3);
}

.logo:hover,
.logo:focus-visible {
    transform: scale(1.05) rotate(-2deg);
    box-shadow: 0 6px 25px rgba(var(--primary-rgb), 0.4);
}

@keyframes gradientShift {
    0%, 100% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
}

/* Navigation Links */
.nav-links {
    display: flex;
    list-style: none;
    gap: 0.5rem;
}

.nav-links a {
    text-decoration: none;
    color: var(--text);
    font-weight: 500;
    font-size: 0.95rem;
    padding: 0.6rem 1.2rem;
    border-radius: var(--radius-sm);
    transition: all var(--transition);
    position: relative;
    overflow: hidden;
}

.nav-links a::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, rgba(var(--primary-rgb), 0.1), rgba(var(--accent-rgb), 0.1));
    opacity: 0;
    transition: opacity var(--transition);
    border-radius: var(--radius-sm);
}

.nav-links a:hover::before,
.nav-links a:focus-visible::before,
.nav-links a.active::before {
    opacity: 1;
}

.nav-links a:hover,
.nav-links a:focus-visible,
.nav-links a.active {
    color: var(--primary);
}

/* Theme Toggle Button */
.theme-toggle {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    padding: 0.6rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition);
    color: var(--text);
    font-size: 1.1rem;
    margin-left: 1rem;
}

.theme-toggle:hover,
.theme-toggle:focus-visible {
    background: var(--primary);
    color: white;
    border-color: var(--primary);
    transform: rotate(15deg);
}

.theme-toggle .fa-sun {
    display: none;
}

.theme-toggle .fa-moon {
    display: block;
}

[data-theme="dark"] .theme-toggle .fa-sun {
    display: block;
}

[data-theme="dark"] .theme-toggle .fa-moon {
    display: none;
}

.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text);
    padding: 0.5rem;
    transition: color var(--transition);
    border-radius: var(--radius-sm);
}

.mobile-menu-btn:hover,
.mobile-menu-btn:focus-visible {
    color: var(--primary);
    background-color: var(--bg-alt);
}

/* Nav Right Container */
.nav-right {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

/* ==========================================================================
   5. Hero Section
   ========================================================================== */

#hero {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    padding: calc(var(--header-height) + 2rem) 2rem 4rem;
    position: relative;
    overflow: hidden;
}

/* Animated Background Gradient */
#hero::before {
    content: '';
    position: absolute;
    inset: 0;
    background:
        radial-gradient(ellipse 80% 80% at 50% -20%, rgba(var(--primary-rgb), 0.15), transparent),
        radial-gradient(ellipse 60% 60% at 80% 50%, rgba(var(--accent-rgb), 0.1), transparent),
        radial-gradient(ellipse 60% 60% at 20% 80%, rgba(139, 92, 246, 0.1), transparent);
    animation: heroGradient 15s ease infinite;
}

@keyframes heroGradient {
    0%, 100% { opacity: 1; transform: scale(1); }
    50% { opacity: 0.8; transform: scale(1.1); }
}

/* Floating Shapes Background */
.hero-bg-shapes {
    position: absolute;
    inset: 0;
    overflow: hidden;
    pointer-events: none;
}

.hero-shape {
    position: absolute;
    border-radius: 50%;
    filter: blur(60px);
    opacity: 0.5;
    animation: float 20s ease-in-out infinite;
}

.hero-shape-1 {
    width: 400px;
    height: 400px;
    background: linear-gradient(135deg, rgba(var(--primary-rgb), 0.3), transparent);
    top: -100px;
    right: -100px;
    animation-delay: 0s;
}

.hero-shape-2 {
    width: 300px;
    height: 300px;
    background: linear-gradient(135deg, rgba(var(--accent-rgb), 0.3), transparent);
    bottom: -50px;
    left: -50px;
    animation-delay: -5s;
}

.hero-shape-3 {
    width: 200px;
    height: 200px;
    background: linear-gradient(135deg, rgba(139, 92, 246, 0.3), transparent);
    top: 50%;
    left: 20%;
    animation-delay: -10s;
}

@keyframes float {
    0%, 100% { transform: translate(0, 0) rotate(0deg); }
    25% { transform: translate(30px, -30px) rotate(5deg); }
    50% { transform: translate(-20px, 20px) rotate(-5deg); }
    75% { transform: translate(10px, -10px) rotate(3deg); }
}

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

.hero-greeting {
    font-size: 1.1rem;
    color: var(--primary);
    font-weight: 600;
    margin-bottom: 0.75rem;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    opacity: 0;
    animation: fadeInUp 0.6s ease forwards;
    animation-delay: 0.2s;
}

#hero h1 {
    font-size: clamp(2.5rem, 8vw, 4.5rem);
    font-weight: 800;
    margin-bottom: 1.25rem;
    background: linear-gradient(135deg, var(--text) 0%, var(--primary) 50%, var(--accent) 100%);
    background-size: 200% auto;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    animation: fadeInUp 0.6s ease forwards, gradientText 5s ease infinite;
    animation-delay: 0.4s, 0s;
    opacity: 0;
    line-height: 1.1;
}

@keyframes gradientText {
    0%, 100% { background-position: 0% center; }
    50% { background-position: 200% center; }
}

.hero-title {
    font-size: clamp(1.1rem, 3vw, 1.5rem);
    color: var(--text-light);
    margin-bottom: 0.75rem;
    min-height: 2em;
    opacity: 0;
    animation: fadeInUp 0.6s ease forwards;
    animation-delay: 0.6s;
}

.hero-location {
    color: var(--text-lighter);
    font-size: 1rem;
    margin-bottom: 2.5rem;
    opacity: 0;
    animation: fadeInUp 0.6s ease forwards;
    animation-delay: 0.8s;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}

.hero-location i {
    color: var(--accent);
}

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

/* CTA Buttons */
.hero-cta {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 2.5rem;
    opacity: 0;
    animation: fadeInUp 0.6s ease forwards;
    animation-delay: 1s;
}

.btn {
    padding: 1rem 2rem;
    border-radius: var(--radius-lg);
    text-decoration: none;
    font-weight: 600;
    font-size: 1rem;
    transition: all var(--transition);
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    position: relative;
    overflow: hidden;
    border: none;
    cursor: pointer;
}

.btn::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, rgba(255,255,255,0.2), transparent);
    opacity: 0;
    transition: opacity var(--transition);
}

.btn:hover::before,
.btn:focus-visible::before {
    opacity: 1;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: white;
    box-shadow: 0 4px 20px rgba(var(--primary-rgb), 0.4);
}

.btn-primary:hover,
.btn-primary:focus-visible {
    transform: translateY(-3px) scale(1.02);
    box-shadow: 0 8px 30px rgba(var(--primary-rgb), 0.5);
}

.btn-primary:active {
    transform: translateY(-1px) scale(0.98);
}

.btn-secondary {
    background: var(--glass-bg);
    backdrop-filter: blur(10px);
    color: var(--text);
    border: 2px solid var(--border);
}

.btn-secondary:hover,
.btn-secondary:focus-visible {
    border-color: var(--primary);
    color: var(--primary);
    background: rgba(var(--primary-rgb), 0.1);
    transform: translateY(-3px);
}

/* Social Links */
.hero-social {
    display: flex;
    gap: 1rem;
    justify-content: center;
    opacity: 0;
    animation: fadeInUp 0.6s ease forwards;
    animation-delay: 1.2s;
}

.hero-social a {
    width: 52px;
    height: 52px;
    border-radius: var(--radius);
    background: var(--glass-bg);
    backdrop-filter: blur(10px);
    border: 1px solid var(--glass-border);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text);
    font-size: 1.25rem;
    text-decoration: none;
    transition: all var(--transition-bounce);
    position: relative;
    overflow: hidden;
}

.hero-social a::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, var(--primary), var(--accent));
    opacity: 0;
    transition: opacity var(--transition);
}

.hero-social a i {
    position: relative;
    z-index: 1;
}

.hero-social a:hover,
.hero-social a:focus-visible {
    transform: translateY(-5px) scale(1.1);
    border-color: transparent;
    color: white;
    box-shadow: 0 10px 30px rgba(var(--primary-rgb), 0.4);
}

.hero-social a:hover::before,
.hero-social a:focus-visible::before {
    opacity: 1;
}

/* Scroll Indicator */
.scroll-indicator {
    position: absolute;
    bottom: 2rem;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-lighter);
    opacity: 0;
    animation: fadeInUp 0.6s ease forwards, bounce 2s ease-in-out infinite;
    animation-delay: 1.5s, 2s;
}

.scroll-indicator span {
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
}

.scroll-indicator i {
    font-size: 1.25rem;
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% { transform: translateY(0); }
    40% { transform: translateY(-12px); }
    60% { transform: translateY(-6px); }
}

/* ==========================================================================
   6. Section Styles
   ========================================================================== */

section {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: var(--section-padding);
    position: relative;
}

/* Section reveal animation */
.reveal {
    opacity: 0;
    transform: translateY(60px);
    transition: all 0.8s cubic-bezier(0.5, 0, 0, 1);
}

.reveal.active {
    opacity: 1;
    transform: translateY(0);
}

/* Staggered children animation */
.reveal-stagger > * {
    opacity: 0;
    transform: translateY(40px);
    transition: all 0.6s cubic-bezier(0.5, 0, 0, 1);
}

.reveal-stagger.active > *:nth-child(1) { transition-delay: 0.1s; }
.reveal-stagger.active > *:nth-child(2) { transition-delay: 0.2s; }
.reveal-stagger.active > *:nth-child(3) { transition-delay: 0.3s; }
.reveal-stagger.active > *:nth-child(4) { transition-delay: 0.4s; }
.reveal-stagger.active > *:nth-child(5) { transition-delay: 0.5s; }
.reveal-stagger.active > *:nth-child(6) { transition-delay: 0.6s; }

.reveal-stagger.active > * {
    opacity: 1;
    transform: translateY(0);
}

h2 {
    font-size: clamp(2rem, 5vw, 2.75rem);
    font-weight: 700;
    margin-bottom: 3.5rem;
    text-align: center;
    position: relative;
}

h2::after {
    content: '';
    display: block;
    width: 80px;
    height: 4px;
    background: linear-gradient(90deg, var(--primary), var(--accent));
    margin: 1.25rem auto 0;
    border-radius: 2px;
}

/* ==========================================================================
   7. About Section
   ========================================================================== */

#about {
    background: var(--bg-alt);
}

.about-content {
    display: grid;
    grid-template-columns: 1.5fr 1fr;
    gap: 4rem;
    align-items: start;
}

.about-text p {
    font-size: 1.1rem;
    color: var(--text-light);
    margin-bottom: 1.5rem;
    line-height: 1.9;
}

.about-highlights {
    display: flex;
    gap: 2rem;
    margin-top: 2.5rem;
}

.highlight {
    text-align: center;
    padding: 1.5rem;
    background: var(--glass-bg);
    backdrop-filter: blur(10px);
    border-radius: var(--radius);
    border: 1px solid var(--glass-border);
    flex: 1;
    transition: all var(--transition);
}

.highlight:hover,
.highlight:focus-within {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.highlight-number {
    display: block;
    font-size: 2.75rem;
    font-weight: 800;
    background: linear-gradient(135deg, var(--primary), var(--accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    line-height: 1.2;
}

.highlight-label {
    font-size: 0.9rem;
    color: var(--text-light);
    margin-top: 0.25rem;
}

/* Expertise Card - Glassmorphism */
.about-expertise {
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    padding: 2.5rem;
    border-radius: var(--radius-lg);
    border: 1px solid var(--glass-border);
    box-shadow: var(--glass-shadow);
    position: relative;
    overflow: hidden;
}

.about-expertise::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary), var(--accent), var(--accent-secondary));
}

.about-expertise h3 {
    font-size: 1.25rem;
    margin-bottom: 1.75rem;
    color: var(--text);
}

.about-expertise ul {
    list-style: none;
}

.about-expertise li {
    padding: 0.875rem 0;
    color: var(--text-light);
    display: flex;
    align-items: center;
    gap: 1rem;
    border-bottom: 1px solid var(--border);
    transition: all var(--transition);
}

.about-expertise li:last-child {
    border-bottom: none;
}

.about-expertise li:hover {
    padding-left: 0.5rem;
    color: var(--text);
}

.about-expertise li i {
    color: var(--accent);
    font-size: 1rem;
    width: 24px;
    height: 24px;
    background: rgba(var(--accent-rgb), 0.1);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

/* ==========================================================================
   8. Experience Timeline
   ========================================================================== */

.timeline {
    position: relative;
    padding-left: 3rem;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    height: 100%;
    width: 3px;
    background: linear-gradient(180deg, var(--primary), var(--accent), var(--accent-secondary));
    border-radius: 3px;
}

.timeline-item {
    position: relative;
    padding-bottom: 3.5rem;
}

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

.timeline-marker {
    position: absolute;
    left: -3rem;
    top: 0;
    width: 20px;
    height: 20px;
    background: var(--bg);
    border-radius: 50%;
    transform: translateX(-50%);
    border: 4px solid var(--primary);
    box-shadow: 0 0 0 4px rgba(var(--primary-rgb), 0.2);
    transition: all var(--transition);
    z-index: 1;
}

.timeline-item:hover .timeline-marker,
.timeline-item:focus-within .timeline-marker {
    background: var(--primary);
    box-shadow: 0 0 0 8px rgba(var(--primary-rgb), 0.2);
    transform: translateX(-50%) scale(1.2);
}

.timeline-content {
    background: var(--bg-card);
    padding: 2rem 2.5rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
    margin-left: 1.5rem;
    transition: all var(--transition);
    position: relative;
    border: 1px solid var(--border);
}

.timeline-content::before {
    content: '';
    position: absolute;
    left: -8px;
    top: 20px;
    width: 16px;
    height: 16px;
    background: var(--bg-card);
    border-left: 1px solid var(--border);
    border-bottom: 1px solid var(--border);
    transform: rotate(45deg);
}

.timeline-content:hover,
.timeline-content:focus-within {
    transform: translateX(10px);
    box-shadow: var(--shadow-xl);
    border-color: rgba(var(--primary-rgb), 0.3);
}

.timeline-header h3 {
    font-size: 1.4rem;
    margin-bottom: 0.5rem;
    color: var(--text);
}

.timeline-header .company {
    display: inline-block;
    font-size: 1.1rem;
    color: var(--primary);
    font-weight: 600;
    margin-bottom: 0.75rem;
    padding: 0.25rem 0.75rem;
    background: rgba(var(--primary-rgb), 0.1);
    border-radius: var(--radius-sm);
}

.timeline-header .date,
.timeline-header .location {
    font-size: 0.9rem;
    color: var(--text-lighter);
    margin-right: 1.5rem;
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
}

.timeline-details {
    list-style: none;
    margin-top: 1.5rem;
}

.timeline-details li {
    position: relative;
    padding-left: 1.5rem;
    margin-bottom: 0.875rem;
    color: var(--text-light);
    font-size: 0.95rem;
    line-height: 1.7;
}

.timeline-details li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0.65rem;
    width: 8px;
    height: 8px;
    background: linear-gradient(135deg, var(--accent), var(--primary));
    border-radius: 50%;
}

/* ==========================================================================
   9. Skills Section
   ========================================================================== */

#skills {
    background: var(--bg-alt);
}

.skills-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 2rem;
}

.skill-category {
    background: var(--bg-card);
    padding: 2rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
    border: 1px solid var(--border);
    transition: all var(--transition);
    position: relative;
    overflow: hidden;
}

.skill-category::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, rgba(var(--primary-rgb), 0.03), rgba(var(--accent-rgb), 0.03));
    opacity: 0;
    transition: opacity var(--transition);
}

.skill-category:hover,
.skill-category:focus-within {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl), var(--shadow-glow);
    border-color: rgba(var(--primary-rgb), 0.3);
}

.skill-category:hover::before,
.skill-category:focus-within::before {
    opacity: 1;
}

.skill-category h3 {
    font-size: 1.15rem;
    margin-bottom: 1.5rem;
    color: var(--text);
    display: flex;
    align-items: center;
    gap: 0.75rem;
    position: relative;
}

.skill-category h3 i {
    color: var(--primary);
    font-size: 1.25rem;
    width: 40px;
    height: 40px;
    background: rgba(var(--primary-rgb), 0.1);
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
}

.skill-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    position: relative;
    padding: 0;
    list-style: none;
}

.skill-tag {
    background: linear-gradient(135deg, rgba(var(--primary-rgb), 0.08), rgba(var(--accent-rgb), 0.08));
    color: var(--text);
    padding: 0.6rem 1.25rem;
    border-radius: var(--radius-lg);
    font-size: 0.9rem;
    font-weight: 500;
    border: 1px solid rgba(var(--primary-rgb), 0.15);
    transition: all var(--transition-bounce);
    cursor: default;
    position: relative;
    overflow: hidden;
}

.skill-tag::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, var(--primary), var(--accent));
    opacity: 0;
    transition: opacity var(--transition);
}

.skill-tag span {
    position: relative;
    z-index: 1;
}

.skill-tag:hover {
    color: white;
    border-color: transparent;
    transform: translateY(-3px) scale(1.05);
    box-shadow: 0 8px 20px rgba(var(--primary-rgb), 0.3);
}

.skill-tag:hover::before {
    opacity: 1;
}

/* ==========================================================================
   10. Education Section
   ========================================================================== */

.education-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 2rem;
    margin-bottom: 4rem;
}

.education-card {
    background: var(--bg-card);
    padding: 3rem 2.5rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
    text-align: center;
    transition: all var(--transition);
    border: 1px solid var(--border);
    position: relative;
    overflow: hidden;
}

.education-card::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary), var(--accent));
    transform: scaleX(0);
    transition: transform var(--transition);
}

.education-card:hover,
.education-card:focus-within {
    transform: translateY(-10px);
    box-shadow: var(--shadow-xl);
}

.education-card:hover::after,
.education-card:focus-within::after {
    transform: scaleX(1);
}

.education-icon {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, var(--primary), var(--accent));
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1.75rem;
    transition: all var(--transition-bounce);
}

.education-card:hover .education-icon,
.education-card:focus-within .education-icon {
    transform: scale(1.1) rotate(5deg);
    box-shadow: 0 10px 30px rgba(var(--primary-rgb), 0.4);
}

.education-icon i {
    font-size: 2rem;
    color: white;
}

.education-card h3 {
    font-size: 1.3rem;
    margin-bottom: 0.75rem;
}

.education-school {
    color: var(--primary);
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.education-detail {
    color: var(--text-light);
    font-size: 0.95rem;
}

.education-year {
    display: inline-block;
    margin-top: 1.25rem;
    background: linear-gradient(135deg, rgba(var(--primary-rgb), 0.1), rgba(var(--accent-rgb), 0.1));
    padding: 0.4rem 1.25rem;
    border-radius: var(--radius-lg);
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--primary);
}

.certifications-title {
    text-align: center;
    font-size: 1.75rem;
    margin-bottom: 2.5rem;
    color: var(--text);
}

.certifications-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
}

.cert-card {
    background: var(--bg-card);
    padding: 1.75rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    display: flex;
    align-items: center;
    gap: 1.25rem;
    border: 1px solid var(--border);
    transition: all var(--transition);
}

.cert-card:hover,
.cert-card:focus-within {
    transform: translateX(8px);
    box-shadow: var(--shadow-lg);
    border-color: rgba(var(--accent-rgb), 0.3);
}

.cert-card i {
    font-size: 2.25rem;
    color: var(--accent);
    flex-shrink: 0;
}

.cert-card h4 {
    font-size: 1rem;
    margin-bottom: 0.35rem;
    color: var(--text);
}

.cert-card time {
    font-size: 0.85rem;
    color: var(--text-lighter);
}

/* ==========================================================================
   11. Contact Section
   ========================================================================== */

#contact {
    background: var(--bg-alt);
    text-align: center;
}

.contact-intro {
    font-size: 1.25rem;
    color: var(--text-light);
    margin-bottom: 3.5rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.contact-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
    max-width: 1000px;
    margin: 0 auto;
}

.contact-card {
    background: var(--bg-card);
    padding: 3rem 2rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
    text-decoration: none;
    color: var(--text);
    transition: all var(--transition);
    border: 1px solid var(--border);
    position: relative;
    overflow: hidden;
}

.contact-card::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, rgba(var(--primary-rgb), 0.05), rgba(var(--accent-rgb), 0.05));
    opacity: 0;
    transition: opacity var(--transition);
}

.contact-card:hover,
.contact-card:focus-visible {
    transform: translateY(-10px);
    box-shadow: var(--shadow-xl), var(--shadow-glow);
    border-color: rgba(var(--primary-rgb), 0.3);
}

.contact-card:hover::before,
.contact-card:focus-visible::before {
    opacity: 1;
}

.contact-card i {
    font-size: 2.75rem;
    margin-bottom: 1.25rem;
    display: block;
    background: linear-gradient(135deg, var(--primary), var(--accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    transition: all var(--transition-bounce);
    position: relative;
}

.contact-card:hover i,
.contact-card:focus-visible i {
    transform: scale(1.15);
}

.contact-card h3 {
    font-size: 1.3rem;
    margin-bottom: 0.75rem;
    position: relative;
}

.contact-card p {
    color: var(--text-light);
    font-size: 0.95rem;
    position: relative;
    word-break: break-word;
}

/* ==========================================================================
   12. Footer
   ========================================================================== */

footer {
    text-align: center;
    padding: 3rem 2rem;
    background: var(--secondary);
    color: var(--text-lighter);
    position: relative;
}

footer::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--primary), var(--accent), transparent);
}

footer p {
    font-size: 0.95rem;
}

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

footer a:hover,
footer a:focus-visible {
    color: var(--accent);
    text-decoration: underline;
}

/* ==========================================================================
   13. Back to Top Button
   ========================================================================== */

.back-to-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, var(--primary), var(--accent));
    color: white;
    border: none;
    border-radius: var(--radius);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: all var(--transition);
    z-index: 999;
    box-shadow: 0 4px 20px rgba(var(--primary-rgb), 0.4);
}

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

.back-to-top:hover,
.back-to-top:focus-visible {
    transform: translateY(-5px);
    box-shadow: 0 8px 30px rgba(var(--primary-rgb), 0.5);
}

/* ==========================================================================
   14. Responsive Breakpoints
   ========================================================================== */

@media (max-width: 1024px) {
    :root {
        --section-padding: 5rem 1.5rem;
    }

    .about-content {
        grid-template-columns: 1fr;
        gap: 3rem;
    }
}

@media (max-width: 768px) {
    :root {
        --section-padding: 4rem 1.25rem;
        --header-height: 70px;
    }

    .nav-links {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: var(--glass-bg);
        backdrop-filter: blur(20px);
        flex-direction: column;
        padding: 1.5rem;
        gap: 0.5rem;
        border-bottom: 1px solid var(--glass-border);
        box-shadow: var(--shadow-lg);
    }

    .nav-links.active {
        display: flex;
    }

    .nav-links a {
        padding: 1rem;
        text-align: center;
    }

    .mobile-menu-btn {
        display: block;
    }

    .nav-right {
        flex-direction: row-reverse;
    }

    .theme-toggle {
        margin-left: 0;
        margin-right: 0.5rem;
    }

    #hero h1 {
        font-size: clamp(2rem, 10vw, 3rem);
    }

    .hero-cta {
        flex-direction: column;
        align-items: center;
        gap: 1rem;
    }

    .btn {
        width: 100%;
        max-width: 280px;
        justify-content: center;
    }

    .about-highlights {
        flex-wrap: wrap;
        gap: 1rem;
    }

    .highlight {
        flex: 1 1 calc(50% - 0.5rem);
        min-width: 140px;
    }

    h2 {
        font-size: 1.75rem;
    }

    .timeline {
        padding-left: 2rem;
    }

    .timeline-content {
        margin-left: 1rem;
        padding: 1.5rem;
    }

    .timeline-content::before {
        display: none;
    }

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

@media (max-width: 480px) {
    :root {
        --section-padding: 3rem 1rem;
    }

    nav {
        padding: 1rem;
    }

    .logo {
        width: 42px;
        height: 42px;
        font-size: 1rem;
    }

    .hero-greeting {
        font-size: 0.9rem;
    }

    .hero-social a {
        width: 46px;
        height: 46px;
    }

    .about-highlights {
        flex-direction: column;
    }

    .highlight {
        flex: 1 1 100%;
    }

    .education-grid,
    .certifications-grid,
    .contact-cards {
        grid-template-columns: 1fr;
    }

    .timeline-header .date,
    .timeline-header .location {
        display: block;
        margin-right: 0;
        margin-bottom: 0.35rem;
    }

    .back-to-top {
        bottom: 1.5rem;
        right: 1.5rem;
        width: 44px;
        height: 44px;
    }
}

@media (max-width: 360px) {
    nav {
        padding: 0.75rem;
    }

    section {
        padding: 2.5rem 0.75rem;
    }

    #hero {
        padding-top: calc(var(--header-height) + 1rem);
    }

    h2 {
        font-size: 1.5rem;
        margin-bottom: 2.5rem;
    }

    .btn {
        padding: 0.875rem 1.5rem;
        font-size: 0.9rem;
    }

    .timeline-content {
        margin-left: 0.5rem;
        padding: 1.25rem;
    }

    .contact-card {
        padding: 2rem 1.5rem;
    }
}

/* ==========================================================================
   15. Reduced Motion Support
   ========================================================================== */

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

    html {
        scroll-behavior: auto;
    }

    .reveal {
        opacity: 1;
        transform: none;
    }

    .reveal-stagger > * {
        opacity: 1;
        transform: none;
    }

    /* Remove all transform animations on hover */
    .btn:hover,
    .btn:focus-visible,
    .logo:hover,
    .logo:focus-visible,
    .hero-social a:hover,
    .hero-social a:focus-visible,
    .highlight:hover,
    .timeline-content:hover,
    .timeline-content:focus-within,
    .timeline-item:hover .timeline-marker,
    .skill-category:hover,
    .skill-category:focus-within,
    .skill-tag:hover,
    .education-card:hover,
    .education-card:focus-within,
    .education-card:hover .education-icon,
    .cert-card:hover,
    .cert-card:focus-within,
    .contact-card:hover,
    .contact-card:focus-visible,
    .back-to-top:hover,
    .back-to-top:focus-visible {
        transform: none !important;
    }

    .scroll-indicator {
        animation: none;
    }

    #hero::before {
        animation: none;
    }

    .hero-shape {
        animation: none;
    }

    #hero h1 {
        animation: none;
        opacity: 1;
    }

    .hero-greeting,
    .hero-title,
    .hero-location,
    .hero-cta,
    .hero-social {
        animation: none;
        opacity: 1;
    }
}

/* ==========================================================================
   16. High Contrast Mode
   ========================================================================== */

@media (prefers-contrast: high) {
    :root {
        --shadow: 0 0 0 1px var(--text);
        --shadow-lg: 0 0 0 2px var(--text);
        --border: var(--text);
    }

    .btn-primary {
        border: 2px solid white;
    }

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

    a:focus-visible,
    button:focus-visible {
        outline: 3px solid var(--text);
        outline-offset: 3px;
    }
}

/* ==========================================================================
   17. Print Styles
   ========================================================================== */

@media print {
    *,
    *::before,
    *::after {
        background: white !important;
        color: black !important;
        box-shadow: none !important;
        text-shadow: none !important;
    }

    header,
    .scroll-indicator,
    .back-to-top,
    .hero-social,
    .hero-cta,
    .skip-link,
    .theme-toggle,
    .mobile-menu-btn,
    .hero-bg-shapes {
        display: none !important;
    }

    body {
        font-size: 12pt;
        line-height: 1.4;
    }

    #hero {
        min-height: auto;
        padding: 2rem;
    }

    #hero h1 {
        background: none;
        -webkit-text-fill-color: black;
        color: black;
    }

    section {
        padding: 2rem;
        page-break-inside: avoid;
    }

    h1, h2, h3, h4, h5, h6 {
        page-break-after: avoid;
    }

    .timeline-content,
    .skill-category,
    .education-card,
    .cert-card,
    .contact-card {
        border: 1px solid #ddd;
        page-break-inside: avoid;
    }

    a[href]::after {
        content: " (" attr(href) ")";
        font-size: 0.8em;
        color: #666;
    }

    a[href^="#"]::after,
    a[href^="mailto:"]::after,
    a[href^="javascript:"]::after {
        content: "";
    }
}