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

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

:root {
    /* Colors */
    --color-bg: #0f172a;
    --color-surface: #1e293b;
    --color-surface-light: #334155;
    --color-text-primary: #f1f5f9;
    --color-text-secondary: #cbd5e1;
    --color-text-muted: #94a3b8;
    --color-accent: #3b82f6;
    --color-accent-hover: #2563eb;
    --color-accent-alt: #10b981;
    --color-border: #334155;

    /* Typography */
    --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    --font-mono: "SF Mono", Monaco, "Cascadia Code", "Roboto Mono", Consolas, monospace;

    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;
    --spacing-3xl: 6rem;

    /* Other */
    --border-radius: 8px;
    --transition: all 0.3s ease;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-sans);
    background-color: var(--color-bg);
    color: var(--color-text-secondary);
    line-height: 1.6;
    font-size: 16px;
}

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

h1, h2, h3, h4, h5, h6 {
    color: var(--color-text-primary);
    font-weight: 700;
    line-height: 1.2;
}

h1 {
    font-size: clamp(2.5rem, 5vw, 4rem);
}

h2 {
    font-size: clamp(1.75rem, 3vw, 2.5rem);
}

h3 {
    font-size: clamp(1.25rem, 2vw, 1.5rem);
}

p {
    margin-bottom: 1rem;
}

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

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

ul {
    list-style: none;
}

/* ========================================
   Layout Components
   ======================================== */

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 clamp(1rem, 5vw, 2rem);
}

.section {
    padding: var(--spacing-2xl) 0;
}

.section-alt {
    background-color: var(--color-surface);
}

.section-title {
    margin-bottom: var(--spacing-xl);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.section-title::after {
    content: '';
    flex: 1;
    height: 1px;
    background-color: var(--color-border);
    max-width: 300px;
}

.section-number {
    color: var(--color-accent);
    font-family: var(--font-mono);
    font-size: 1.25rem;
    font-weight: 400;
}

/* ========================================
   Skip Link (Accessibility)
   ======================================== */

.skip-link {
    position: absolute;
    top: -100px;
    left: 0;
    background: var(--color-accent);
    color: white;
    padding: var(--spacing-sm) var(--spacing-md);
    z-index: 100;
}

.skip-link:focus {
    top: 0;
}

/* ========================================
   Navigation
   ======================================== */

.nav {
    position: sticky;
    top: 0;
    background-color: rgba(15, 23, 42, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--color-border);
    z-index: 50;
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 64px;
}

.nav-brand {
    font-weight: 700;
    color: var(--color-text-primary);
    font-size: 1.25rem;
}

.nav-brand:hover {
    color: var(--color-accent);
}

.nav-menu {
    display: flex;
    gap: var(--spacing-lg);
    align-items: center;
}

.nav-link {
    color: var(--color-text-secondary);
    font-size: 0.9375rem;
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--color-accent);
    transition: width 0.3s ease;
}

.nav-link:hover {
    color: var(--color-accent);
}

.nav-link:hover::after {
    width: 100%;
}

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 4px;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-xs);
}

.nav-toggle span {
    width: 24px;
    height: 2px;
    background-color: var(--color-text-primary);
    transition: var(--transition);
}

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

.hero {
    min-height: 90vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    position: relative;
}

.hero-content {
    max-width: 800px;
}

.hero-title {
    margin-bottom: var(--spacing-sm);
    background: linear-gradient(135deg, #f1f5f9 0%, #cbd5e1 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    color: var(--color-accent);
    font-weight: 600;
    margin-bottom: var(--spacing-md);
}

.hero-description {
    color: var(--color-text-muted);
    font-size: 1.125rem;
    margin-bottom: var(--spacing-xl);
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

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

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

.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border-radius: 6px;
    font-weight: 500;
    transition: var(--transition);
    cursor: pointer;
    border: 2px solid transparent;
}

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

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

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

.btn-secondary:hover {
    background-color: var(--color-accent);
    color: white;
}

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

.about-content {
    max-width: 800px;
}

.about-text p {
    margin-bottom: var(--spacing-md);
    line-height: 1.8;
}

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

.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-lg);
}

.skill-card {
    background-color: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    padding: var(--spacing-md);
    transition: var(--transition);
}

.skill-card:hover {
    transform: translateY(-4px);
    border-color: var(--color-accent);
}

.skill-card h3 {
    color: var(--color-accent);
    margin-bottom: var(--spacing-sm);
    font-size: 1.125rem;
}

.skill-tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
}

.skill-tags span {
    background-color: var(--color-surface-light);
    color: var(--color-text-secondary);
    padding: 0.25rem 0.75rem;
    border-radius: 4px;
    font-size: 0.875rem;
}

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

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: var(--spacing-lg);
}

.project-card {
    background-color: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    padding: var(--spacing-md);
    transition: var(--transition);
    display: flex;
    flex-direction: column;
    min-height: 250px;
}

.project-card:hover {
    border-color: var(--color-accent);
    transform: translateY(-4px);
}

.project-card h3 {
    margin-bottom: var(--spacing-sm);
    color: var(--color-text-primary);
}

.project-card p {
    flex: 1;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-md);
}

.project-tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
}

.project-tags span {
    background-color: rgba(16, 185, 129, 0.1);
    color: var(--color-accent-alt);
    padding: 0.25rem 0.75rem;
    border-radius: 4px;
    font-size: 0.875rem;
}

/* ========================================
   Experience Section
   ======================================== */

.timeline {
    position: relative;
    padding-left: var(--spacing-lg);
    border-left: 2px solid var(--color-border);
    margin-bottom: var(--spacing-2xl);
}

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

.timeline-marker {
    position: absolute;
    left: -2.25rem;
    top: 0.375rem;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background-color: var(--color-accent);
    border: 3px solid var(--color-bg);
}

.timeline-content h3 {
    color: var(--color-text-primary);
    margin-bottom: 0.25rem;
}

.timeline-content h4 {
    color: var(--color-accent);
    font-weight: 500;
    margin-bottom: var(--spacing-xs);
}

.timeline-date {
    color: var(--color-text-muted);
    font-size: 0.875rem;
    margin-bottom: var(--spacing-sm);
}

.timeline-content ul {
    list-style: disc;
    list-style-position: inside;
    color: var(--color-text-secondary);
}

.timeline-content li {
    margin-bottom: 0.5rem;
}

/* ========================================
   Education Section
   ======================================== */

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

.education-item h3 {
    color: var(--color-text-primary);
    margin-bottom: 0.25rem;
}

.education-item h4 {
    color: var(--color-accent);
    font-weight: 500;
    margin-bottom: var(--spacing-xs);
}

.education-date {
    color: var(--color-text-muted);
    font-size: 0.875rem;
    margin-bottom: var(--spacing-sm);
}

.education-item p {
    color: var(--color-text-secondary);
}

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

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

.contact-content p {
    margin-bottom: var(--spacing-lg);
    font-size: 1.125rem;
    color: var(--color-text-secondary);
}

.contact-links {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
    align-items: center;
}

.contact-link {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-md);
    background-color: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    color: var(--color-text-secondary);
    transition: var(--transition);
    min-width: 250px;
}

.contact-link:hover {
    border-color: var(--color-accent);
    background-color: rgba(59, 130, 246, 0.1);
    color: var(--color-accent);
}

.contact-link svg {
    flex-shrink: 0;
}

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

.footer {
    background-color: var(--color-surface);
    border-top: 1px solid var(--color-border);
    padding: var(--spacing-lg) 0;
    text-align: center;
}

.footer p {
    color: var(--color-text-muted);
    font-size: 0.875rem;
    margin: 0;
}

/* ========================================
   Responsive Design
   ======================================== */

@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: 64px;
        right: -100%;
        width: 100%;
        max-width: 300px;
        height: calc(100vh - 64px);
        background-color: var(--color-surface);
        flex-direction: column;
        padding: var(--spacing-lg);
        gap: var(--spacing-md);
        transition: right 0.3s ease;
        border-left: 1px solid var(--color-border);
        align-items: flex-start;
    }

    .nav-menu.active {
        right: 0;
    }

    .nav-toggle {
        display: flex;
    }

    .nav-toggle.active span:nth-child(1) {
        transform: rotate(45deg) translate(5px, 5px);
    }

    .nav-toggle.active span:nth-child(2) {
        opacity: 0;
    }

    .nav-toggle.active span:nth-child(3) {
        transform: rotate(-45deg) translate(6px, -6px);
    }

    .hero {
        min-height: 80vh;
    }

    .hero-description {
        font-size: 1rem;
    }

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

    .section-title::after {
        max-width: 100px;
    }

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

    .timeline {
        padding-left: var(--spacing-md);
    }

    .timeline-marker {
        left: -1.625rem;
    }

    .contact-link {
        min-width: auto;
        width: 100%;
    }
}

@media (max-width: 480px) {
    .hero-cta {
        flex-direction: column;
        width: 100%;
    }

    .btn {
        width: 100%;
        text-align: center;
    }
}