/* ===================================
   CSS VARIABLES & DESIGN SYSTEM
   =================================== */
:root {
    /* Colors - Dark Mode */
    --bg-primary: #1a1a1a;
    --bg-secondary: #242424;
    --bg-tertiary: #2d2d2d;

    --text-primary: #ffffff;
    --text-secondary: #b4b4b4;
    --text-tertiary: #8a8a8a;

    --accent-primary: #6366f1;
    --accent-secondary: #4f46e5;
    --accent-tertiary: #3b82f6;

    --border-color: rgba(255, 255, 255, 0.1);
    --border-color-hover: rgba(255, 255, 255, 0.2);

    /* Spacing System (8px base) */
    --spacing-xs: 8px;
    --spacing-sm: 16px;
    --spacing-md: 24px;
    --spacing-lg: 32px;
    --spacing-xl: 48px;
    --spacing-xxl: 64px;

    /* Border Radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 16px;
    --radius-xl: 24px;

    /* Shadows */
    --shadow-light: 0 2px 8px rgba(0, 0, 0, 0.15);
    --shadow-medium: 0 4px 16px rgba(0, 0, 0, 0.25);
    --shadow-heavy: 0 8px 32px rgba(0, 0, 0, 0.35);

    /* Typography */
    --font-family: 'Public Sans', ui-sans-serif, system-ui, -apple-system, sans-serif;

    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-medium: 0.3s ease;
    --transition-slow: 0.5s ease;
}

/* ===================================
   RESET & BASE STYLES
   =================================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

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

/* ===================================
   TYPOGRAPHY
   =================================== */
h1, h2, h3, h4, h5, h6 {
    line-height: 1.2;
    font-weight: 600;
}

.section-title {
    font-size: 3rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: var(--spacing-xl);
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-tertiary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.subsection-title {
    font-size: 1.75rem;
    margin-bottom: var(--spacing-lg);
    color: var(--text-primary);
}

/* ===================================
   NAVIGATION
   =================================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(26, 26, 26, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-color);
    padding: var(--spacing-sm) 0;
}

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

.nav-logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: var(--spacing-lg);
}

.nav-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    transition: color var(--transition-fast);
    position: relative;
}

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

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    right: 0;
    height: 2px;
    background: var(--accent-primary);
}

.nav-toggle {
    display: none;
    flex-direction: column;
    background: none;
    border: none;
    cursor: pointer;
    gap: 4px;
}

.nav-toggle span {
    width: 25px;
    height: 3px;
    background: var(--text-primary);
    border-radius: 3px;
    transition: var(--transition-fast);
}

/* ===================================
   HERO SECTION
   =================================== */
.hero-section {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-xxl) var(--spacing-md);
    margin-top: 60px;
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.1), rgba(59, 130, 246, 0.1));
}

.hero-content {
    text-align: center;
}

.hero-image-container {
    margin-bottom: var(--spacing-lg);
}

.hero-image-placeholder {
    width: 200px;
    height: 200px;
    margin: 0 auto;
    border-radius: 50%;
    background: var(--bg-secondary);
    border: 4px solid var(--accent-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    color: var(--text-secondary);
    box-shadow: 0 0 40px rgba(99, 102, 241, 0.3);
}

.hero-name {
    font-size: 4rem;
    margin-bottom: var(--spacing-sm);
}

.hero-title {
    font-size: 1.75rem;
    color: var(--accent-primary);
    margin-bottom: var(--spacing-xs);
    font-weight: 600;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
}

/* ===================================
   ABOUT SECTION
   =================================== */
.about-section {
    padding: var(--spacing-xxl) 0;
}

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

.about-text p {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
    line-height: 1.8;
}

.about-actions {
    margin-top: var(--spacing-lg);
    text-align: center;
}

.btn {
    display: inline-block;
    padding: 12px 32px;
    border-radius: var(--radius-md);
    text-decoration: none;
    font-weight: 600;
    transition: var(--transition-medium);
    cursor: pointer;
    border: none;
    font-size: 1rem;
}

.btn-primary {
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    color: var(--text-primary);
    box-shadow: var(--shadow-medium);
}

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

/* ===================================
   TIMELINE SECTION
   =================================== */
.timeline-section {
    padding: var(--spacing-xxl) 0;
    background: var(--bg-secondary);
}

.timeline-container {
    position: relative;
    overflow-x: auto;
    padding: var(--spacing-xl) 0;
}

.timeline-line {
    position: absolute;
    top: 50%;
    left: 0;
    right: 0;
    height: 2px;
    background: var(--border-color);
    z-index: 0;
}

.timeline-items {
    display: flex;
    gap: var(--spacing-xxl);
    padding: 0 var(--spacing-md);
    position: relative;
    z-index: 1;
    min-width: max-content;
}

.timeline-item {
    position: relative;
    min-width: 250px;
}

.timeline-dot {
    width: 20px;
    height: 20px;
    background: var(--accent-primary);
    border-radius: 50%;
    position: absolute;
    top: -10px;
    left: 50%;
    transform: translateX(-50%);
    box-shadow: 0 0 0 4px var(--bg-secondary),
                0 0 0 8px rgba(99, 102, 241, 0.2);
}

.timeline-content {
    background: var(--bg-tertiary);
    padding: var(--spacing-md);
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-color);
    margin-top: var(--spacing-md);
    transition: var(--transition-medium);
    cursor: pointer;
}

.timeline-content:hover {
    border-color: var(--accent-primary);
    transform: translateY(-4px);
    box-shadow: var(--shadow-medium);
}

.timeline-icon {
    font-size: 2.5rem;
    text-align: center;
    margin-bottom: var(--spacing-sm);
}

.timeline-content h3 {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-xs);
}

.timeline-date {
    color: var(--accent-primary);
    font-size: 0.875rem;
    font-weight: 600;
    display: block;
    margin-bottom: var(--spacing-xs);
}

.timeline-desc {
    color: var(--text-secondary);
    font-size: 0.9375rem;
}

/* ===================================
   SKILLS SECTION
   =================================== */
.skills-section {
    padding: var(--spacing-xxl) 0;
}

.skills-category {
    margin-bottom: var(--spacing-xl);
}

.skills-category-title {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-md);
    color: var(--text-primary);
}

.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-md);
}

.skill-item {
    background: var(--bg-secondary);
    padding: var(--spacing-md);
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-color);
    display: flex;
    gap: var(--spacing-sm);
    transition: var(--transition-medium);
}

.skill-item:hover {
    border-color: var(--accent-primary);
    transform: translateY(-2px);
}

.skill-icon {
    font-size: 2.5rem;
    flex-shrink: 0;
}

.skill-info {
    flex: 1;
}

.skill-info h4 {
    font-size: 1.125rem;
    margin-bottom: var(--spacing-xs);
}

.skill-bar {
    height: 8px;
    background: var(--bg-tertiary);
    border-radius: 4px;
    overflow: hidden;
    margin-bottom: var(--spacing-xs);
}

.skill-progress {
    height: 100%;
    background: linear-gradient(90deg, var(--accent-primary), var(--accent-tertiary));
    border-radius: 4px;
    transition: width var(--transition-slow);
}

.skill-level {
    font-size: 0.875rem;
    color: var(--text-tertiary);
}

.learning-grid {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
}

.learning-item {
    background: var(--bg-secondary);
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.learning-badge {
    font-size: 1.25rem;
}

/* ===================================
   EXPERIENCE SECTION
   =================================== */
.experience-section {
    padding: var(--spacing-xxl) 0;
    background: var(--bg-secondary);
}

.experience-subsection {
    margin-bottom: var(--spacing-xl);
}

.experience-grid {
    display: grid;
    gap: var(--spacing-md);
}

.experience-card {
    background: var(--bg-tertiary);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-color);
    display: flex;
    gap: var(--spacing-md);
    transition: var(--transition-medium);
}

.experience-card:hover {
    border-color: var(--accent-primary);
    transform: translateX(4px);
}

.experience-logo-placeholder {
    width: 80px;
    height: 80px;
    background: var(--bg-secondary);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    border: 1px solid var(--border-color);
    font-size: 2rem;
}

.experience-content {
    flex: 1;
}

.experience-role {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-xs);
}

.experience-company {
    color: var(--accent-primary);
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
}

.experience-date {
    color: var(--text-tertiary);
    font-size: 0.875rem;
    display: block;
    margin-bottom: var(--spacing-sm);
}

.experience-description {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-sm);
    line-height: 1.6;
}

.experience-technologies {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
}

.tech-tag {
    background: var(--bg-secondary);
    padding: 4px 12px;
    border-radius: var(--radius-sm);
    font-size: 0.8125rem;
    color: var(--accent-primary);
    border: 1px solid rgba(99, 102, 241, 0.3);
}

/* ===================================
   PROJECTS SECTION
   =================================== */
.projects-section {
    padding: var(--spacing-xxl) 0;
}

.project-filters {
    display: flex;
    justify-content: center;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-lg);
    flex-wrap: wrap;
}

.filter-btn {
    padding: 8px 20px;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    cursor: pointer;
    transition: var(--transition-fast);
}

.filter-btn:hover,
.filter-btn.active {
    background: var(--accent-primary);
    color: var(--text-primary);
    border-color: var(--accent-primary);
}

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

.project-card {
    background: var(--bg-secondary);
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-color);
    overflow: hidden;
    transition: var(--transition-medium);
}

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

.project-card.featured {
    grid-column: span 2;
}

.project-image-placeholder {
    height: 200px;
    background: var(--bg-tertiary);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-tertiary);
    border-bottom: 1px solid var(--border-color);
}

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

.project-badge {
    display: inline-block;
    background: var(--accent-primary);
    color: var(--text-primary);
    padding: 4px 12px;
    border-radius: var(--radius-sm);
    font-size: 0.75rem;
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
}

.project-title {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-sm);
}

.project-description {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-sm);
    line-height: 1.6;
}

.project-tech-stack {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
    margin-bottom: var(--spacing-sm);
}

.tech-icon {
    background: var(--bg-tertiary);
    padding: 4px 10px;
    border-radius: var(--radius-sm);
    font-size: 0.8125rem;
    color: var(--text-secondary);
}

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

.project-link {
    color: var(--accent-primary);
    text-decoration: none;
    font-weight: 600;
    font-size: 0.9375rem;
    transition: var(--transition-fast);
}

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

/* ===================================
   CERTIFICATIONS SECTION
   =================================== */
.certifications-section {
    padding: var(--spacing-xxl) 0;
    background: var(--bg-secondary);
}

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

.certification-card {
    background: var(--bg-tertiary);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-color);
    text-align: center;
    transition: var(--transition-medium);
}

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

.certification-badge {
    font-size: 3rem;
    margin-bottom: var(--spacing-sm);
}

.certification-name {
    font-size: 1.125rem;
    margin-bottom: var(--spacing-xs);
}

.certification-issuer {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-xs);
}

.certification-date {
    color: var(--text-tertiary);
    font-size: 0.875rem;
}

/* ===================================
   MY SITES SECTION
   =================================== */
.sites-section {
    padding: var(--spacing-xxl) 0;
}

.section-subtitle {
    text-align: center;
    color: var(--text-secondary);
    font-size: 1.125rem;
    max-width: 600px;
    margin: -var(--spacing-md) auto var(--spacing-xl) auto;
}

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

.site-card {
    background: var(--bg-secondary);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    text-decoration: none;
    color: var(--text-primary);
    transition: var(--transition-medium);
    position: relative;
    overflow: hidden;
}

.site-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-tertiary));
    opacity: 0;
    transition: opacity var(--transition-medium);
}

.site-card:hover::before {
    opacity: 0.05;
}

.site-card:hover {
    border-color: var(--accent-primary);
    transform: translateY(-4px);
    box-shadow: var(--shadow-medium);
}

.site-icon {
    font-size: 3rem;
    flex-shrink: 0;
    z-index: 1;
}

.site-content {
    flex: 1;
    z-index: 1;
}

.site-name {
    font-size: 1.25rem;
    margin-bottom: 4px;
    font-weight: 600;
}

.site-url {
    color: var(--text-secondary);
    font-size: 0.9375rem;
    margin-bottom: var(--spacing-xs);
    font-family: 'Courier New', monospace;
}

.site-badge {
    display: inline-block;
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    color: var(--text-primary);
    padding: 4px 12px;
    border-radius: var(--radius-sm);
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

/* ===================================
   CONTACT SECTION
   =================================== */
.contact-section {
    padding: var(--spacing-xxl) 0;
}

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

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

.contact-item {
    display: flex;
    gap: var(--spacing-sm);
    align-items: flex-start;
}

.contact-icon {
    font-size: 1.5rem;
    flex-shrink: 0;
}

.contact-item h4 {
    font-size: 1rem;
    margin-bottom: 4px;
}

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

.contact-item a:hover {
    color: var(--accent-tertiary);
}

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

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

.social-icon {
    padding: 10px 20px;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    text-decoration: none;
    transition: var(--transition-fast);
}

.social-icon:hover {
    background: var(--accent-primary);
    border-color: var(--accent-primary);
}

.contact-form {
    background: var(--bg-secondary);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-color);
}

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

.form-group label {
    display: block;
    margin-bottom: var(--spacing-xs);
    color: var(--text-secondary);
    font-weight: 500;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 12px 16px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-family: var(--font-family);
    font-size: 1rem;
    transition: var(--transition-fast);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.form-group textarea {
    resize: vertical;
}

/* ===================================
   FOOTER
   =================================== */
.footer {
    background: var(--bg-secondary);
    padding: var(--spacing-lg) 0;
    text-align: center;
    border-top: 1px solid var(--border-color);
}

.footer p {
    color: var(--text-tertiary);
    font-size: 0.9375rem;
}

/* ===================================
   RESPONSIVE DESIGN
   =================================== */
@media (max-width: 1024px) {
    .project-card.featured {
        grid-column: span 1;
    }
}

@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: 60px;
        left: -100%;
        width: 100%;
        height: calc(100vh - 60px);
        background: rgba(26, 26, 26, 0.98);
        backdrop-filter: blur(10px);
        flex-direction: column;
        padding: var(--spacing-lg);
        transition: left var(--transition-medium);
    }

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

    .nav-toggle {
        display: flex;
    }

    .section-title {
        font-size: 2rem;
    }

    .hero-name {
        font-size: 2.5rem;
    }

    .hero-title {
        font-size: 1.25rem;
    }

    .timeline-items {
        flex-direction: column;
        padding-bottom: var(--spacing-xxl);
    }

    .timeline-line {
        top: 0;
        left: 50%;
        width: 2px;
        height: 100%;
        transform: translateX(-50%);
    }

    .timeline-item {
        width: 100%;
    }

    .timeline-dot {
        left: 50%;
        top: 0;
    }

    .contact-content {
        grid-template-columns: 1fr;
    }

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

    .experience-card {
        flex-direction: column;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 var(--spacing-sm);
    }

    .hero-name {
        font-size: 2rem;
    }

    .section-title {
        font-size: 1.75rem;
    }

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

    .certifications-grid {
        grid-template-columns: 1fr;
    }

    .sites-grid {
        grid-template-columns: 1fr;
    }
}