/* ===================================
   CSS Reset & Base Styles
   =================================== */

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

:root {
    /* Color Palette */
    --color-bg: #F7F9FB;
    --color-text: #1F2937;
    --color-accent: #0B78D1;
    --color-accent-hover: #095fa8;
    --color-card-bg: #FFFFFF;
    --color-border: #E5E7EB;
    --color-shadow: rgba(0, 0, 0, 0.1);
    --color-shadow-hover: rgba(0, 0, 0, 0.15);

    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', sans-serif;
    --font-size-base: 1rem;
    --font-size-h1: 2.25rem;
    --font-size-h2: 1.875rem;
    --font-size-h3: 1.5rem;
    --font-size-small: 0.875rem;

    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 0.75rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    --spacing-3xl: 4rem;

    /* Border Radius */
    --radius-sm: 6px;
    --radius-md: 12px;
    --radius-lg: 16px;

    /* Transitions */
    --transition-fast: 150ms ease-in-out;
    --transition-normal: 250ms ease-in-out;
}

html {
    scroll-behavior: smooth;
}

/* Respect prefers-reduced-motion */
@media (prefers-reduced-motion: reduce) {
    html {
        scroll-behavior: auto;
    }

    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

body {
    font-family: var(--font-family);
    font-size: var(--font-size-base);
    line-height: 1.6;
    color: var(--color-text);
    background-color: var(--color-bg);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

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

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

/* Visible focus states for accessibility */
a:focus-visible, button:focus-visible, input:focus-visible, textarea:focus-visible {
    outline: 2px solid var(--color-accent);
    outline-offset: 2px;
}

ul {
    list-style: none;
}

/* ===================================
   Typography
   =================================== */

h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: var(--spacing-md);
}

h1 {
    font-size: var(--font-size-h1);
}

h2 {
    font-size: var(--font-size-h2);
}

h3 {
    font-size: var(--font-size-h3);
}

p {
    margin-bottom: var(--spacing-md);
}

/* ===================================
   Layout Utilities
   =================================== */

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.section-title {
    text-align: center;
    margin-bottom: var(--spacing-2xl);
    position: relative;
}

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

/* ===================================
   Buttons
   =================================== */

.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-sm) var(--spacing-lg);
    font-size: var(--font-size-base);
    font-weight: 600;
    border: none;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all var(--transition-normal);
    text-align: center;
}

.btn-primary {
    background-color: var(--color-accent);
    color: #FFFFFF;
}

.btn-primary:hover, .btn-primary:focus {
    background-color: var(--color-accent-hover);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px var(--color-shadow);
    color: #FFFFFF;
}

.btn-secondary {
    background-color: transparent;
    color: var(--color-accent);
    border: 2px solid var(--color-accent);
}

.btn-secondary:hover, .btn-secondary:focus {
    background-color: var(--color-accent);
    color: #FFFFFF;
    transform: translateY(-2px);
}

.btn-small {
    padding: var(--spacing-xs) var(--spacing-md);
    font-size: var(--font-size-small);
}

/* ===================================
   Header & Navigation
   =================================== */

.header {
    position: sticky;
    top: 0;
    z-index: 1000;
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: 0 2px 8px var(--color-shadow);
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-md) var(--spacing-lg);
    max-width: 1200px;
    margin: 0 auto;
}

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

.logo-text {
    display: none;
}

.nav-links {
    display: none;
    gap: var(--spacing-xl);
}

.nav-links a {
    font-weight: 500;
    color: var(--color-text);
    position: relative;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--color-accent);
    transition: width var(--transition-normal);
}

.nav-links a:hover::after, .nav-links a:focus::after {
    width: 100%;
}

/* Hamburger Menu */
.hamburger {
    display: flex;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-xs);
}

.hamburger-line {
    width: 25px;
    height: 3px;
    background-color: var(--color-text);
    border-radius: 2px;
    transition: all var(--transition-normal);
}

.hamburger[aria-expanded="true"] .hamburger-line:nth-child(1) {
    transform: rotate(45deg) translate(7px, 7px);
}

.hamburger[aria-expanded="true"] .hamburger-line:nth-child(2) {
    opacity: 0;
}

.hamburger[aria-expanded="true"] .hamburger-line:nth-child(3) {
    transform: rotate(-45deg) translate(7px, -7px);
}

/* Mobile Menu */
.mobile-menu {
    display: none;
    background-color: var(--color-card-bg);
    padding: var(--spacing-lg);
    box-shadow: 0 4px 8px var(--color-shadow);
}

.mobile-menu[aria-hidden="false"] {
    display: block;
}

.mobile-menu ul {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.mobile-menu a {
    font-size: 1.125rem;
    font-weight: 500;
    color: var(--color-text);
    padding: var(--spacing-sm) 0;
}

/* ===================================
   Hero Section
   =================================== */

.hero {
    padding: var(--spacing-3xl) 0;
    min-height: 80vh;
    display: flex;
    align-items: center;
}

.hero-content {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-2xl);
}

.hero-text h1 {
    font-size: 1.75rem;
    margin-bottom: var(--spacing-sm);
}

.hero-text h2 {
    font-size: 1.125rem;
    font-weight: 500;
    color: #6B7280;
    margin-bottom: var(--spacing-md);
}

.value-proposition {
    font-size: 1.125rem;
    color: var(--color-text);
    margin-bottom: var(--spacing-lg);
}

.cta-group {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
}

.contact-line {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
    padding-top: var(--spacing-md);
    border-top: 1px solid var(--color-border);
}

.phone-link {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    font-weight: 500;
}

.social-links {
    display: flex;
    gap: var(--spacing-md);
}

.social-links a {
    color: var(--color-text);
    transition: all var(--transition-normal);
}

.social-links a:hover, .social-links a:focus {
    color: var(--color-accent);
    transform: translateY(-2px);
}

.hero-image {
    display: flex;
    justify-content: center;
}

.hero-image img {
    border-radius: 50%;
    width: 300px;
    height: 300px;
    object-fit: cover;
    box-shadow: 0 8px 24px var(--color-shadow);
}

/* ===================================
   About Section
   =================================== */

.about {
    padding: var(--spacing-3xl) 0;
    background-color: #FFFFFF;
}

.about-content {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-2xl);
}

.about-text p {
    font-size: 1.0625rem;
    line-height: 1.7;
}

.availability-list {
    list-style: disc;
    padding-left: var(--spacing-lg);
    margin: var(--spacing-lg) 0;
}

.availability-list li {
    margin-bottom: var(--spacing-sm);
}

.contact-info {
    font-size: 1rem;
    margin-top: var(--spacing-lg);
}

.about-image {
    display: flex;
    justify-content: center;
}

.about-image img {
    border-radius: var(--radius-md);
    width: 100%;
    max-width: 300px;
    height: auto;
    object-fit: cover;
    box-shadow: 0 4px 16px var(--color-shadow);
}

/* ===================================
   Projects Section
   =================================== */

.projects {
    padding: var(--spacing-3xl) 0;
}

.projects-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-xl);
}

.project-card {
    background-color: var(--color-card-bg);
    border-radius: var(--radius-md);
    overflow: hidden;
    box-shadow: 0 4px 12px var(--color-shadow);
    transition: all var(--transition-normal);
}

.project-card:hover, .project-card:focus-within {
    transform: translateY(-4px);
    box-shadow: 0 8px 24px var(--color-shadow-hover);
}

.project-image {
    width: 100%;
    height: 240px;
    overflow: hidden;
    background-color: var(--color-border);
}

.project-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform var(--transition-normal);
}

.project-card:hover .project-image img {
    transform: scale(1.05);
}

.project-content {
    padding: var(--spacing-lg);
}

.project-content h3 {
    margin-bottom: var(--spacing-sm);
}

.project-content p {
    color: #6B7280;
    margin-bottom: var(--spacing-md);
}

.tech-tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
    margin-bottom: var(--spacing-lg);
}

.tag {
    padding: var(--spacing-xs) var(--spacing-sm);
    background-color: #E0F2FE;
    color: var(--color-accent);
    border-radius: var(--radius-sm);
    font-size: var(--font-size-small);
    font-weight: 500;
}

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

/* ===================================
   Modals
   =================================== */

.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 2000;
    display: none;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-md);
}

.modal[aria-hidden="false"] {
    display: flex;
}

.modal-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(4px);
}

.modal-content {
    position: relative;
    background-color: var(--color-card-bg);
    border-radius: var(--radius-md);
    padding: var(--spacing-xl);
    max-width: 800px;
    max-height: 90vh;
    overflow-y: auto;
    box-shadow: 0 16px 48px rgba(0, 0, 0, 0.3);
}

.modal-close {
    position: absolute;
    top: var(--spacing-md);
    right: var(--spacing-md);
    background: none;
    border: none;
    font-size: 2rem;
    cursor: pointer;
    color: var(--color-text);
    line-height: 1;
    padding: var(--spacing-xs);
}

.modal-close:hover {
    color: var(--color-accent);
}

.modal-content h3 {
    margin-bottom: var(--spacing-lg);
}

.modal-content img {
    margin-bottom: var(--spacing-lg);
    border-radius: var(--radius-sm);
}

.modal-content p {
    margin-bottom: var(--spacing-md);
}

.modal-buttons {
    margin-top: var(--spacing-xl);
}

/* ===================================
   Skills Section
   =================================== */

.skills {
    padding: var(--spacing-3xl) 0;
    background-color: #FFFFFF;
}

.skills-content {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-2xl);
}

.technical-skills h3, .soft-skills h3 {
    margin-bottom: var(--spacing-lg);
}

.skill-item {
    margin-bottom: var(--spacing-lg);
}

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

.skill-name {
    font-weight: 600;
}

.skill-level {
    font-size: var(--font-size-small);
    color: #6B7280;
}

.skill-bar {
    width: 100%;
    height: 10px;
    background-color: var(--color-border);
    border-radius: var(--radius-sm);
    overflow: hidden;
}

.skill-progress {
    height: 100%;
    background: linear-gradient(90deg, var(--color-accent), #06b6d4);
    border-radius: var(--radius-sm);
    transition: width 1s ease-in-out;
}

.skill-chips {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-md);
}

.chip {
    padding: var(--spacing-sm) var(--spacing-lg);
    background-color: var(--color-bg);
    border: 2px solid var(--color-accent);
    color: var(--color-accent);
    border-radius: 999px;
    font-weight: 500;
}

/* ===================================
   Resume Section
   =================================== */

.resume {
    padding: var(--spacing-3xl) 0;
}

.resume-content {
    max-width: 800px;
    margin: 0 auto;
}

.resume-summary {
    font-size: 1.0625rem;
    line-height: 1.7;
    margin-bottom: var(--spacing-xl);
    text-align: center;
}

.resume-download {
    display: flex;
    margin: 0 auto var(--spacing-2xl);
}

.timeline-section {
    margin-top: var(--spacing-2xl);
}

.timeline-section summary {
    font-size: 1.25rem;
    font-weight: 600;
    cursor: pointer;
    padding: var(--spacing-md);
    background-color: var(--color-bg);
    border-radius: var(--radius-sm);
    margin-bottom: var(--spacing-lg);
}

.timeline-section summary:hover {
    background-color: #E5E7EB;
}

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

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

.timeline-item {
    position: relative;
    margin-bottom: var(--spacing-2xl);
}

.timeline-marker {
    position: absolute;
    left: -28px;
    top: 4px;
    width: 12px;
    height: 12px;
    background-color: var(--color-accent);
    border-radius: 50%;
    border: 3px solid var(--color-bg);
}

.timeline-content h4 {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-xs);
}

.timeline-meta {
    font-weight: 600;
    color: var(--color-accent);
    margin-bottom: var(--spacing-xs);
}

.timeline-date {
    font-size: var(--font-size-small);
    color: #6B7280;
    margin-bottom: var(--spacing-sm);
}

/* ===================================
   Contact Section
   =================================== */

.contact {
    padding: var(--spacing-3xl) 0;
    background-color: #FFFFFF;
}

.contact-content {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-2xl);
}

.contact-info-block p {
    font-size: 1.0625rem;
    margin-bottom: var(--spacing-lg);
}

.contact-details {
    margin-bottom: var(--spacing-lg);
}

.contact-details p {
    margin-bottom: var(--spacing-md);
}

.contact-social {
    margin-top: var(--spacing-md);
}

.social-row {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
    margin-top: var(--spacing-sm);
}

.social-row a {
    font-weight: 500;
}

.contact-form {
    background-color: var(--color-bg);
    padding: var(--spacing-xl);
    border-radius: var(--radius-md);
}

.form-group {
    margin-bottom: var(--spacing-lg);
}

.form-group label {
    display: block;
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
}

.form-group input, .form-group textarea {
    width: 100%;
    padding: var(--spacing-sm) var(--spacing-md);
    border: 2px solid var(--color-border);
    border-radius: var(--radius-sm);
    font-family: inherit;
    font-size: var(--font-size-base);
    transition: border-color var(--transition-fast);
}

.form-group input:focus, .form-group textarea:focus {
    border-color: var(--color-accent);
    outline: none;
}

.privacy-note {
    font-size: var(--font-size-small);
    color: #6B7280;
    margin-bottom: var(--spacing-md);
}

/* ===================================
   Footer
   =================================== */

.footer {
    background-color: var(--color-text);
    color: #FFFFFF;
    padding: var(--spacing-xl) 0;
    text-align: center;
}

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

.footer p {
    margin: 0;
    font-size: var(--font-size-small);
}

.footer-nav {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: var(--spacing-md);
}

.footer-nav a {
    color: #D1D5DB;
    font-size: var(--font-size-small);
}

.footer-nav a:hover, .footer-nav a:focus {
    color: #FFFFFF;
}

/* ===================================
   Responsive Design - Tablet (640px+)
   =================================== */

@media (min-width: 640px) {
    :root {
        --font-size-h1: 2.5rem;
        --font-size-h2: 2rem;
    }

    .logo-text {
        display: inline;
    }

    .hero-text h1 {
        font-size: 2.25rem;
    }

    .hero-text h2 {
        font-size: 1.25rem;
    }

    .contact-line {
        flex-direction: row;
        align-items: center;
    }

    .about-content {
        flex-direction: row;
        align-items: center;
    }

    .about-text {
        flex: 1;
    }

    .about-image {
        flex-shrink: 0;
    }

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

    .contact-content {
        display: grid;
        grid-template-columns: 1fr 1fr;
        gap: var(--spacing-2xl);
    }

    .social-row {
        flex-direction: row;
        flex-wrap: wrap;
    }
}

/* ===================================
   Responsive Design - Desktop (1024px+)
   =================================== */

@media (min-width: 1024px) {
    :root {
        --font-size-h1: 3rem;
        --font-size-h2: 2.25rem;
    }

    .container {
        padding: 0 var(--spacing-xl);
    }

    .hamburger {
        display: none;
    }

    .nav-links {
        display: flex;
    }

    .mobile-menu {
        display: none !important;
    }

    .hero-content {
        flex-direction: row-reverse;
        align-items: center;
        justify-content: space-between;
    }

    .hero-text {
        flex: 1;
    }

    .hero-image {
        flex-shrink: 0;
    }

    .hero-image img {
        width: 400px;
        height: 400px;
    }

    .hero-text h1 {
        font-size: 3rem;
    }

    .hero-text h2 {
        font-size: 1.5rem;
    }

    .value-proposition {
        font-size: 1.25rem;
    }

    .skills-content {
        display: grid;
        grid-template-columns: 2fr 1fr;
        gap: var(--spacing-3xl);
    }
}