:root {
    --primary-color: #2563eb;
    --secondary-color: #0ea5e9;
    --accent-color: #06b6d4;
    --text-color: #1f2937;
    --text-light: #6b7280;
    --bg-color: #f9fafb;
    --bg-card: #ffffff;
    --white: #ffffff;
    --max-width: 1200px;
    --header-height: 80px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --gradient-hero: linear-gradient(135deg, #2563eb 0%, #0ea5e9 100%);
}

[data-theme="dark"] {
    --primary-color: #3b82f6;
    --secondary-color: #38bdf8;
    --accent-color: #22d3ee;
    --text-color: #f3f4f6;
    --text-light: #9ca3af;
    --bg-color: #111827;
    --bg-card: #1f2937;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.4);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', sans-serif;
    color: var(--text-color);
    background-color: var(--bg-color);
    line-height: 1.7;
    overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6 {
    font-family: 'Montserrat', sans-serif;
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 1rem;
}

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

ul {
    list-style: none;
}

/* Utilities */
.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 20px;
}

.text-center { text-align: center; }
.mb-1 { margin-bottom: 1rem; }
.mb-2 { margin-bottom: 2rem; }
.mb-3 { margin-bottom: 3rem; }

/* Header */
header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: var(--header-height);
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    z-index: 1000;
    box-shadow: var(--shadow-sm);
    display: flex;
    align-items: center;
    transition: var(--transition);
}

[data-theme="dark"] header {
    background: rgba(17, 24, 39, 0.8);
}

header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
}

.logo {
    font-size: 1.5rem;
    font-weight: 800;
    background: var(--gradient-hero);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    letter-spacing: -0.5px;
}

.nav-links {
    display: flex;
    gap: 30px;
    align-items: center;
}

.nav-links a {
    font-weight: 600;
    font-size: 0.95rem;
    color: var(--text-color);
    position: relative;
}

.nav-links a:not(.btn)::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: -4px;
    left: 0;
    background-color: var(--primary-color);
    transition: var(--transition);
}

.nav-links a:not(.btn):hover::after {
    width: 100%;
}

.lang-switch {
    display: flex;
    align-items: center;
    gap: 5px;
    margin: 0 15px;
}

.lang-btn {
    background: none;
    border: none;
    cursor: pointer;
    font-weight: 600;
    color: var(--text-light);
    font-size: 0.9rem;
    padding: 2px 5px;
    transition: var(--transition);
}

.lang-btn:hover, .lang-btn.active {
    color: var(--primary-color);
}

.separator {
    color: var(--text-light);
    font-size: 0.9rem;
}

.menu-toggle {
    display: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text-color);
}

#theme-toggle {
    background: none;
    border: none;
    cursor: pointer;
    font-size: 1.2rem;
    color: var(--text-color);
    transition: var(--transition);
    padding: 5px;
    display: flex;
    align-items: center;
    justify-content: center;
}

#theme-toggle:hover {
    transform: rotate(15deg) scale(1.1);
    color: var(--primary-color);
}

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    background: var(--gradient-hero);
    color: var(--white);
    padding-top: var(--header-height);
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg width="20" height="20" viewBox="0 0 20 20" xmlns="http://www.w3.org/2000/svg"><circle cx="2" cy="2" r="1" fill="rgba(255,255,255,0.1)"/></svg>');
    opacity: 0.3;
}

.hero-content {
    position: relative;
    z-index: 1;
    max-width: 800px;
    animation: fadeInUp 1s ease-out;
}

.hero h1 {
    font-size: 3.5rem;
    font-weight: 800;
    margin-bottom: 1rem;
    letter-spacing: -1px;
    text-shadow: 0 2px 10px rgba(0,0,0,0.2);
}

.hero h2 {
    font-size: 1.5rem;
    font-weight: 500;
    margin-bottom: 2rem;
    opacity: 0.9;
}

.hero p {
    font-size: 1.1rem;
    margin-bottom: 2.5rem;
    opacity: 0.9;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.btn {
    display: inline-block;
    padding: 14px 35px;
    background-color: var(--white);
    color: var(--primary-color);
    border-radius: 50px;
    font-weight: 700;
    transition: var(--transition);
    box-shadow: 0 4px 15px rgba(0,0,0,0.2);
    border: 2px solid transparent;
}

.btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 25px rgba(0,0,0,0.3);
    background-color: transparent;
    border-color: var(--white);
    color: var(--white);
}

.btn-outline {
    background-color: transparent;
    border: 2px solid var(--white);
    color: var(--white);
    margin-left: 15px;
}

.btn-outline:hover {
    background-color: var(--white);
    color: var(--primary-color);
}

/* Sections */
section {
    padding: 100px 0;
}

.section-title {
    text-align: center;
    margin-bottom: 60px;
    position: relative;
    display: inline-block;
    left: 50%;
    transform: translateX(-50%);
}

.section-title h2 {
    font-size: 2.5rem;
    color: var(--text-color);
    margin-bottom: 15px;
}

.section-title::after {
    content: '';
    display: block;
    width: 60px;
    height: 4px;
    background: var(--gradient-hero);
    margin: 0 auto;
    border-radius: 2px;
}

/* Statistics Section */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 30px;
    max-width: 1000px;
    margin: 0 auto;
}

.stat-card {
    background: var(--bg-color);
    padding: 40px 20px;
    border-radius: 20px;
    text-align: center;
    transition: var(--transition);
    border: 2px solid transparent;
    position: relative;
    overflow: hidden;
}

.stat-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--gradient-hero);
    transform: scaleX(0);
    transition: var(--transition);
}

.stat-card:hover {
    transform: translateY(-10px);
    border-color: var(--primary-color);
    box-shadow: var(--shadow-lg);
}

.stat-card:hover::before {
    transform: scaleX(1);
}

.stat-icon {
    font-size: 3rem;
    background: var(--gradient-hero);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 20px;
    animation: float 3s ease-in-out infinite;
}

.stat-card:nth-child(2) .stat-icon {
    animation-delay: 0.5s;
}

.stat-card:nth-child(3) .stat-icon {
    animation-delay: 1s;
}

.stat-card:nth-child(4) .stat-icon {
    animation-delay: 1.5s;
}

@keyframes float {
    0%, 100% {
        transform: translateY(0px);
    }
    50% {
        transform: translateY(-10px);
    }
}

.stat-number {
    font-size: 3.5rem;
    font-weight: 800;
    color: var(--text-color);
    font-family: 'Montserrat', sans-serif;
    margin-bottom: 10px;
    line-height: 1;
}

.stat-number::after {
    content: '+';
    font-size: 2rem;
    margin-left: 5px;
    color: var(--primary-color);
}

.stat-label {
    font-size: 1rem;
    color: var(--text-light);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
}

/* About */
.about-card {
    background: var(--bg-card);
    padding: 40px;
    border-radius: 20px;
    box-shadow: var(--shadow-lg);
    text-align: center;
    max-width: 900px;
    margin: 0 auto;
    border: 1px solid rgba(0,0,0,0.05);
}

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

/* Experience Timeline */
.timeline {
    position: relative;
    max-width: 1000px;
    margin: 0 auto;
}

.timeline::after {
    content: '';
    position: absolute;
    width: 4px;
    background: rgba(229, 231, 235, 0.5);
    top: 0;
    bottom: 0;
    left: 50%;
    margin-left: -2px;
    border-radius: 2px;
}

.timeline-item {
    padding: 10px 50px;
    position: relative;
    background-color: inherit;
    width: 50%;
    box-sizing: border-box;
}

.timeline-item::after {
    content: '';
    position: absolute;
    width: 24px;
    height: 24px;
    right: -12px;
    background-color: var(--white);
    border: 4px solid var(--primary-color);
    top: 20px;
    border-radius: 50%;
    z-index: 1;
    box-shadow: 0 0 0 4px rgba(79, 70, 229, 0.2);
}

.timeline-item.featured::after {
    border-color: var(--accent-color);
    box-shadow: 0 0 0 4px rgba(6, 182, 212, 0.3);
    animation: pulse 2s infinite;
}

.left { left: 0; }
.right { left: 50%; }
.right::after { left: -12px; }

.content {
    padding: 30px;
    background-color: var(--bg-card);
    position: relative;
    border-radius: 15px;
    box-shadow: var(--shadow-md);
    transition: var(--transition);
    border: 1px solid rgba(0,0,0,0.03);
}

.timeline-item.featured .content {
    border: 2px solid var(--accent-color);
    box-shadow: 0 10px 25px -5px rgba(6, 182, 212, 0.2);
    transform: scale(1.02);
}

.timeline-item.featured .content::before {
    content: 'Current';
    position: absolute;
    top: -12px;
    right: 20px;
    background: var(--accent-color);
    color: var(--white);
    padding: 4px 12px;
    border-radius: 12px;
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

[data-theme="dark"] .timeline-item.featured .content {
    box-shadow: 0 10px 25px -5px rgba(34, 211, 238, 0.15);
}

@keyframes pulse {
    0% {
        box-shadow: 0 0 0 0 rgba(6, 182, 212, 0.4);
    }
    70% {
        box-shadow: 0 0 0 10px rgba(6, 182, 212, 0);
    }
    100% {
        box-shadow: 0 0 0 0 rgba(6, 182, 212, 0);
    }
}

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

.date {
    display: inline-block;
    padding: 5px 15px;
    background: rgba(79, 70, 229, 0.1);
    color: var(--primary-color);
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 700;
    margin-bottom: 15px;
}

.content h3 {
    font-size: 1.25rem;
    margin-bottom: 5px;
    color: var(--text-color);
}

.content h4 {
    font-size: 1rem;
    color: var(--text-light);
    font-weight: 500;
    margin-bottom: 15px;
}

/* Skills */
.skills-category {
    margin-bottom: 50px;
}

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

.category-title {
    font-size: 1.5rem;
    color: var(--text-color);
    margin-bottom: 30px;
    text-align: center;
    position: relative;
    padding-bottom: 15px;
}

.category-title::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 50px;
    height: 3px;
    background: var(--gradient-hero);
    border-radius: 2px;
}

.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 20px;
    max-width: 1000px;
    margin: 0 auto;
}

.skill-card {
    background: var(--bg-card);
    padding: 25px 15px;
    border-radius: 15px;
    text-align: center;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    border: 1px solid rgba(0,0,0,0.03);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
}

.skill-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-md);
    border-color: var(--primary-color);
}

.skill-card i {
    font-size: 2.5rem;
    background: var(--gradient-hero);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 10px;
}

.skill-card span {
    font-weight: 600;
    color: var(--text-color);
}

/* Footer */
footer {
    background-color: #111827;
    color: var(--white);
    padding: 60px 0 30px;
    text-align: center;
}

.footer-social {
    display: flex;
    justify-content: center;
    gap: 25px;
    margin-bottom: 30px;
}

.footer-social a {
    width: 50px;
    height: 50px;
    background: rgba(255,255,255,0.1);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    transition: var(--transition);
}

.footer-social a:hover {
    background: var(--primary-color);
    transform: translateY(-3px);
}

/* Animations */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Responsive */
@media screen and (max-width: 768px) {
    .hero h1 { font-size: 2.5rem; }
    
    .nav-links {
        position: absolute;
        right: 0;
        height: 100vh;
        top: var(--header-height);
        background-color: var(--bg-card);
        flex-direction: column;
        align-items: center;
        width: 100%;
        transform: translateX(100%);
        padding-top: 50px;
        box-shadow: -5px 0 15px rgba(0,0,0,0.1);
    }

    .nav-links.active { transform: translateX(0); }
    .menu-toggle { display: block; }

    .timeline::after { left: 31px; }
    .timeline-item { width: 100%; padding-left: 70px; padding-right: 25px; }
    .timeline-item::after { left: 19px; }
    .right { left: 0%; }
    .right::after { left: 19px; }
}

/* Language Switcher */
.header-actions {
    display: flex;
    align-items: center;
    gap: 20px;
}

.lang-btn {
    background: transparent;
    border: 1px solid var(--text-color);
    color: var(--text-color);
    padding: 8px 16px;
    border-radius: 20px;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 8px;
    font-family: 'Inter', sans-serif;
    font-weight: 500;
    transition: all 0.3s ease;
}

.lang-btn:hover {
    background: var(--primary-color);
    border-color: var(--primary-color);
    color: white;
}

.lang-btn i {
    font-size: 1.1rem;
}

/* Mobile Adjustments */
@media (max-width: 768px) {
    .header-actions {
        gap: 15px;
    }
    
    .lang-btn span {
        display: none; /* Hide text on mobile to save space */
    }
    
    .lang-btn {
        padding: 8px;
        border-radius: 50%;
        width: 40px;
        height: 40px;
        justify-content: center;
    }
}

/* Floating Action Button */
.fab-container {
    position: fixed;
    bottom: 30px;
    right: 30px;
    z-index: 999;
    display: flex;
    flex-direction: column-reverse;
    align-items: center;
    gap: 15px;
}

.fab-main {
    width: 60px;
    height: 60px;
    background: var(--gradient-hero);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.5rem;
    cursor: pointer;
    box-shadow: 0 4px 15px rgba(37, 99, 235, 0.4);
    transition: var(--transition);
    animation: pulse-soft 3s infinite;
}

.fab-main:hover {
    transform: scale(1.1);
}

.fab-options {
    display: flex;
    flex-direction: column-reverse;
    gap: 15px;
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: var(--transition);
}

.fab-container:hover .fab-options {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.fab-option {
    width: 50px;
    height: 50px;
    background: var(--bg-card);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-color);
    box-shadow: var(--shadow-md);
    transition: var(--transition);
    border: 1px solid rgba(0,0,0,0.05);
}

.fab-option:hover {
    background: var(--primary-color);
    color: white;
    transform: translateY(-3px);
}

@keyframes pulse-soft {
    0% { box-shadow: 0 0 0 0 rgba(37, 99, 235, 0.4); }
    70% { box-shadow: 0 0 0 15px rgba(37, 99, 235, 0); }
    100% { box-shadow: 0 0 0 0 rgba(37, 99, 235, 0); }
}