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

:root {
    /* Colors */
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --primary-light: #3b82f6;
    --secondary: #64748b;
    --accent: #06b6d4;
    --success: #10b981;
    --warning: #f59e0b;
    --error: #ef4444;
    
    /* Neutrals */
    --white: #ffffff;
    --gray-50: #f8fafc;
    --gray-100: #f1f5f9;
    --gray-200: #e2e8f0;
    --gray-300: #cbd5e1;
    --gray-400: #94a3b8;
    --gray-500: #64748b;
    --gray-600: #475569;
    --gray-700: #334155;
    --gray-800: #1e293b;
    --gray-900: #0f172a;
    
    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 1.875rem;
    --font-size-4xl: 2.25rem;
    --font-size-5xl: 3rem;
    --font-size-6xl: 4rem;
    
    /* 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;
    --space-32: 8rem;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow: 0 1px 3px 0 rgb(0 0 0 / 0.1), 0 1px 2px -1px rgb(0 0 0 / 0.1);
    --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);
    
    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius: 0.5rem;
    --radius-md: 0.75rem;
    --radius-lg: 1rem;
    --radius-xl: 1.5rem;
    --radius-full: 9999px;
    
    /* Transitions*/
    --transition-fast: 150ms ease-in-out;
    --transition: 300ms ease-in-out;
    --transition-slow: 500ms ease-in-out;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    font-size: var(--font-size-base);
    line-height: 1.6;
    color: var(--gray-700);
    background: var(--white);
    overflow-x: hidden;
}

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--space-4);
}

@media (min-width: 768px) {
    .container {
        padding: 0 var(--space-6);
    }
}

/* Header & Navigation */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--gray-200);
    transition: var(--transition);
}

.nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 80px;
}

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

.nav__logo {
    font-size: var(--font-size-xl);
    font-weight: 700;
    color: var(--gray-900);
    text-decoration: none;
    transition: var(--transition-fast);
}

.nav__logo:hover {
    color: var(--primary);
}

.nav__tagline {
    font-size: var(--font-size-xs);
    color: var(--gray-500);
    font-weight: 500;
}

.nav__menu {
    display: none;
    list-style: none;
    gap: var(--space-8);
}

.nav__link {
    color: var(--gray-600);
    text-decoration: none;
    font-weight: 500;
    position: relative;
    transition: var(--transition-fast);
}

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

.nav__link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary);
    transition: var(--transition-fast);
}

.nav__link:hover::after,
.nav__link--active::after {
    width: 100%;
}

.nav__toggle {
    display: flex;
    flex-direction: column;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--space-2);
    gap: 4px;
}

.nav__toggle span {
    width: 24px;
    height: 2px;
    background: var(--gray-700);
    transition: var(--transition-fast);
}

@media (min-width: 768px) {
    .nav__menu {
        display: flex;
    }
    
    .nav__toggle {
        display: none;
    }
}

/* Hero Section */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    overflow: hidden;
    background: linear-gradient(135deg, var(--gray-50) 0%, var(--white) 100%);
}

.hero__background {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        radial-gradient(circle at 25% 25%, var(--primary) 0%, transparent 50%),
        radial-gradient(circle at 75% 75%, var(--accent) 0%, transparent 50%);
    opacity: 0.03;
    animation: float 20s ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: translateY(0px) rotate(0deg); }
    50% { transform: translateY(-20px) rotate(5deg); }
}

.hero__content {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-12);
    align-items: center;
    padding: var(--space-20) 0;
}

.hero__title {
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
    margin-bottom: var(--space-6);
}

.hero__title-main {
    font-size: var(--font-size-4xl);
    font-weight: 800;
    color: var(--gray-900);
    opacity: 1;
    animation: slideUp 0.8s ease-out 0.2s forwards;
}

.hero__title-sub {
    font-size: var(--font-size-2xl);
    font-weight: 600;
    color: var(--gray-600);
    opacity: 1;
    animation: slideUp 0.8s ease-out 0.4s forwards;
}

.hero__title-focus {
    font-size: var(--font-size-xl);
    font-weight: 500;
    color: var(--primary);
    opacity: 1;
    animation: slideUp 0.8s ease-out 0.6s forwards;
}

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

.hero__description {
    font-size: var(--font-size-lg);
    color: var(--gray-600);
    line-height: 1.7;
    margin-bottom: var(--space-8);
    opacity: 1;
    animation: slideUp 0.8s ease-out 0.8s forwards;
}

.hero__cta {
    display: flex;
    gap: var(--space-4);
    flex-wrap: wrap;
    opacity: 1;
    animation: slideUp 0.8s ease-out 1s forwards;
}

.hero__visual {
    display: none;
}

.hero__card {
    background: var(--white);
    border-radius: var(--radius-xl);
    padding: var(--space-8);
    box-shadow: var(--shadow-xl);
    border: 1px solid var(--gray-200);
    backdrop-filter: blur(10px);
}

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

.stat {
    text-align: center;
}

.stat__number {
    display: block;
    font-size: var(--font-size-3xl);
    font-weight: 800;
    color: var(--primary);
    margin-bottom: var(--space-2);
}

.stat__label {
    font-size: var(--font-size-sm);
    color: var(--gray-600);
    font-weight: 500;
}

@media (min-width: 768px) {
    .hero__title-main {
        font-size: var(--font-size-5xl);
    }
    
    .hero__title-sub {
        font-size: var(--font-size-3xl);
    }
    
    .hero__title-focus {
        font-size: var(--font-size-2xl);
    }
}

@media (min-width: 1024px) {
    .hero__content {
        grid-template-columns: 1fr 400px;
    }
    
    .hero__visual {
        display: block;
        opacity: 1;
        animation: slideUp 0.8s ease-out 1.2s forwards;
    }
    
    .hero__title-main {
        font-size: var(--font-size-6xl);
    }
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-2);
    padding: var(--space-3) var(--space-6);
    border-radius: var(--radius);
    text-decoration: none;
    font-weight: 600;
    font-size: var(--font-size-base);
    transition: var(--transition-fast);
    border: 2px solid transparent;
    cursor: pointer;
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.2), transparent);
    transition: var(--transition);
}

.btn:hover::before {
    left: 100%;
}

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

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

.btn--secondary {
    background: var(--gray-100);
    color: var(--gray-700);
}

.btn--secondary:hover {
    background: var(--gray-200);
    transform: translateY(-2px);
}

.btn--outline {
    background: transparent;
    color: var(--primary);
    border-color: var(--primary);
}

.btn--outline:hover {
    background: var(--primary);
    color: var(--white);
    transform: translateY(-2px);
}

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

/* Section Styles */
section {
    padding: var(--space-20) 0;
}

.section-header {
    text-align: center;
    margin-bottom: var(--space-16);
}

.section-title {
    font-size: var(--font-size-3xl);
    font-weight: 800;
    color: var(--gray-900);
    margin-bottom: var(--space-4);
}

.section-subtitle {
    font-size: var(--font-size-lg);
    color: var(--gray-600);
    max-width: 600px;
    margin: 0 auto;
}

@media (min-width: 768px) {
    .section-title {
        font-size: var(--font-size-4xl);
    }
}

/* Expertise Section */
.expertise {
    background: var(--gray-50);
}

.expertise__grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-8);
}

.expertise__card {
    background: var(--white);
    padding: var(--space-8);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
    border: 1px solid var(--gray-200);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

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

.expertise__card:hover::before {
    transform: scaleX(1);
}

.expertise__card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.expertise__icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--primary), var(--accent));
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: var(--space-6);
    color: var(--white);
}

.expertise__icon svg {
    width: 28px;
    height: 28px;
    stroke-width: 2;
}

.expertise__card h3 {
    font-size: var(--font-size-xl);
    font-weight: 700;
    color: var(--gray-900);
    margin-bottom: var(--space-4);
}

.expertise__card p {
    color: var(--gray-600);
    margin-bottom: var(--space-6);
    line-height: 1.7;
}

.expertise__list {
    list-style: none;
}

.expertise__list li {
    color: var(--gray-600);
    padding: var(--space-2) 0;
    position: relative;
    padding-left: var(--space-6);
}

.expertise__list li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--success);
    font-weight: 700;
}

@media (min-width: 768px) {
    .expertise__grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (min-width: 1024px) {
    .expertise__grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

/* Experience Timeline */
.experience {
    background: var(--white);
}

.timeline {
    max-width: 800px;
    margin: 0 auto;
    position: relative;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 30px;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--gray-300);
}

.timeline__item {
    position: relative;
    margin-bottom: var(--space-12);
    padding-left: var(--space-16);
}

.timeline__marker {
    position: absolute;
    left: 22px;
    top: 0;
    width: 16px;
    height: 16px;
    background: var(--gray-400);
    border: 4px solid var(--white);
    border-radius: var(--radius-full);
    box-shadow: var(--shadow);
}

.timeline__item--current .timeline__marker {
    background: var(--primary);
    box-shadow: 0 0 0 4px rgba(37, 99, 235, 0.2);
}

.timeline__content {
    background: var(--white);
    padding: var(--space-6);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
    border: 1px solid var(--gray-200);
    transition: var(--transition);
}

.timeline__content:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-2px);
}

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

.timeline__header h3 {
    font-size: var(--font-size-xl);
    font-weight: 700;
    color: var(--gray-900);
    margin-bottom: var(--space-2);
}

.timeline__company {
    display: block;
    font-weight: 600;
    color: var(--primary);
    margin-bottom: var(--space-1);
}

.timeline__period {
    font-size: var(--font-size-sm);
    color: var(--gray-500);
    font-weight: 500;
}

.timeline__description {
    color: var(--gray-600);
    line-height: 1.7;
    margin-bottom: var(--space-4);
}

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

.tag {
    background: var(--gray-100);
    color: var(--gray-700);
    padding: var(--space-1) var(--space-3);
    border-radius: var(--radius-full);
    font-size: var(--font-size-sm);
    font-weight: 500;
}

@media (min-width: 768px) {
    .timeline::before {
        left: 50%;
        transform: translateX(-50%);
    }
    
    .timeline__item {
        width: 50%;
        padding-left: 0;
        padding-right: var(--space-8);
    }
    
    .timeline__item:nth-child(even) {
        left: 50%;
        padding-left: var(--space-8);
        padding-right: 0;
    }
    
    .timeline__marker {
        left: 50%;
        transform: translateX(-50%);
    }
}

/* CTA Section */
.cta {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: var(--white);
    position: relative;
    overflow: hidden;
}

.cta::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="grain" width="100" height="100" patternUnits="userSpaceOnUse"><circle cx="50" cy="50" r="1" fill="white" opacity="0.1"/></pattern></defs><rect width="100" height="100" fill="url(%23grain)"/></svg>');
    opacity: 0.1;
}

.cta__content {
    text-align: center;
    position: relative;
    z-index: 1;
}

.cta__title {
    font-size: var(--font-size-3xl);
    font-weight: 800;
    margin-bottom: var(--space-6);
}

.cta__description {
    font-size: var(--font-size-lg);
    margin-bottom: var(--space-8);
    opacity: 0.9;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.cta__actions {
    display: flex;
    gap: var(--space-4);
    justify-content: center;
    flex-wrap: wrap;
}

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

.cta .btn--primary:hover {
    background: var(--gray-100);
}

.cta .btn--outline {
    border-color: var(--white);
    color: var(--white);
}

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

@media (min-width: 768px) {
    .cta__title {
        font-size: var(--font-size-4xl);
    }
}

/* Footer */
.footer {
    background: var(--gray-900);
    color: var(--gray-300);
    padding: var(--space-16) 0 var(--space-8);
}

.footer__content {
    display: grid;
    gap: var(--space-12);
}

.footer__main {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-8);
}

.footer__brand h3 {
    color: var(--white);
    font-size: var(--font-size-xl);
    font-weight: 700;
    margin-bottom: var(--space-2);
}

.contact-item {
    display: flex;
    gap: var(--space-3);
    margin-bottom: var(--space-4);
}

.contact-item span {
    font-size: var(--font-size-lg);
}

.contact-item strong {
    color: var(--white);
    display: block;
    margin-bottom: var(--space-1);
}

.contact-item p {
    font-size: var(--font-size-sm);
    opacity: 0.8;
}

.footer__bottom {
    display: flex;
    flex-direction: column;
    gap: var(--space-4);
    align-items: center;
    padding-top: var(--space-8);
    border-top: 1px solid var(--gray-700);
}

.footer__nav {
    display: flex;
    gap: var(--space-6);
}

.footer__nav a {
    color: var(--gray-400);
    text-decoration: none;
    font-size: var(--font-size-sm);
    transition: var(--transition-fast);
}

.footer__nav a:hover {
    color: var(--white);
}

@media (min-width: 768px) {
    .footer__main {
        grid-template-columns: 1fr 2fr;
    }
    
    .footer__bottom {
        flex-direction: row;
        justify-content: space-between;
    }
}

/* Animations & Interactions */
.fade-in {
    opacity: 0;
    transform: translateY(20px);
    transition: var(--transition-slow);
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* Scroll Progress Bar */
.scroll-progress {
    position: fixed;
    top: 80px;
    left: 0;
    width: 0%;
    height: 3px;
    background: linear-gradient(90deg, var(--primary), var(--accent));
    z-index: 1000;
    transition: width 0.1s ease-out;
}

@media (max-width: 767px) {
    .nav__menu {
        display: none;
        position: fixed;
        top: 80px;
        left: 0;
        right: 0;
        background: var(--white);
        border-bottom: 1px solid var(--gray-200);
        padding: var(--space-6);
        opacity: 0;
        transition: opacity 0.3s ease;
        box-shadow: var(--shadow-md);
        max-height: calc(100vh - 80px);
        overflow-y: auto;
    }

    .nav__menu.active {
        display: block;
        opacity: 1;
    }
}

/* Loading Animation */
@keyframes shimmer {
    0% {
        background-position: -200px 0;
    }
    100% {
        background-position: calc(200px + 100%) 0;
    }
}

.loading {
    background: linear-gradient(90deg, #f0f0f0 25%, #e0e0e0 50%, #f0f0f0 75%);
    background-size: 200px 100%;
    animation: shimmer 1.5s infinite;
}