/* ═══════════════════════════════════════════════════════════════
   CHIRAG VASAVA — PORTFOLIO CSS
   Dark / Light Mode · Sticky Navbar · Project Cards · Rich Footer
   ═══════════════════════════════════════════════════════════════ */

/* ── Google Fonts ─────────────────────────────────────────────── */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&family=Fira+Code:wght@400;500&display=swap');

/* ── CSS Custom Properties (Design Tokens) ───────────────────── */
:root {
  /* Dark mode (default) */
  --bg-primary:    #0d1117;
  --bg-secondary:  #161b22;
  --bg-card:       #1a2233;
  --bg-card-hover: #1f2d42;
  --border:        rgba(99, 179, 237, 0.15);
  --border-card:   rgba(99, 179, 237, 0.2);
  --text-primary:  #e6edf3;
  --text-secondary:#8b949e;
  --text-muted:    #586069;
  --accent:        #58a6ff;
  --accent-glow:   rgba(88, 166, 255, 0.25);
  --accent-green:  #3fb950;
  --accent-purple: #a371f7;
  --accent-orange: #f78166;
  --navbar-bg:     rgba(13, 17, 23, 0.92);
  --card-shadow:   0 4px 24px rgba(0,0,0,0.4);
  --hero-grad:     linear-gradient(135deg, #0d1117 0%, #0d1a2e 50%, #0d1117 100%);
  --tag-bg:        rgba(88, 166, 255, 0.12);
  --tag-text:      #58a6ff;
  --footer-bg:     #010409;
  --icon-filter:   invert(1);
  --sun-display:   none;
  --moon-display:  block;
  --nav-brand-color: #58a6ff;
}

[data-theme="light"] {
  --bg-primary:    #f6f8fa;
  --bg-secondary:  #ffffff;
  --bg-card:       #ffffff;
  --bg-card-hover: #f0f6ff;
  --border:        rgba(0,0,0,0.08);
  --border-card:   rgba(0,0,0,0.12);
  --text-primary:  #1c2128;
  --text-secondary:#57606a;
  --text-muted:    #8c959f;
  --accent:        #0969da;
  --accent-glow:   rgba(9, 105, 218, 0.15);
  --accent-green:  #1a7f37;
  --accent-purple: #8250df;
  --accent-orange: #cf222e;
  --navbar-bg:     rgba(246, 248, 250, 0.95);
  --card-shadow:   0 2px 16px rgba(0,0,0,0.1);
  --hero-grad:     linear-gradient(135deg, #e8f4fd 0%, #dbeafe 50%, #e8f4fd 100%);
  --tag-bg:        rgba(9, 105, 218, 0.08);
  --tag-text:      #0969da;
  --footer-bg:     #161b22;
  --icon-filter:   invert(0);
  --sun-display:   block;
  --moon-display:  none;
  --nav-brand-color: #0969da;
}

/* ── Base Reset ──────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: 'Inter', system-ui, sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.7;
  transition: background 0.3s ease, color 0.3s ease;
  overflow-x: hidden;
}

a { text-decoration: none; color: inherit; }
img { display: block; max-width: 100%; }
ul { list-style: none; }

/* ═══════════════════════════════════════════════════════════════
   STICKY NAVBAR
   ═══════════════════════════════════════════════════════════════ */
#navbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  background: var(--navbar-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  transition: background 0.3s ease, border-color 0.3s ease;
}

.nav-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
  height: 60px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

/* Brand */
.nav-brand {
  font-family: 'Fira Code', monospace;
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--nav-brand-color);
  letter-spacing: -0.5px;
  transition: color 0.3s;
  white-space: nowrap;
}
.nav-brand:hover { opacity: 0.8; }

/* Nav links */
.nav-links {
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

.nav-links a {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-secondary);
  padding: 0.4rem 0.75rem;
  border-radius: 6px;
  transition: color 0.2s, background 0.2s;
}
.nav-links a:hover {
  color: var(--text-primary);
  background: var(--border);
}

/* Theme toggle */
#theme-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: 8px;
  border: 1px solid var(--border-card);
  background: transparent;
  cursor: pointer;
  color: var(--text-secondary);
  font-size: 1rem;
  transition: all 0.2s;
  margin-left: 0.5rem;
  flex-shrink: 0;
}
#theme-toggle:hover {
  background: var(--border);
  color: var(--text-primary);
}
#theme-toggle svg { width: 18px; height: 18px; }

.icon-sun  { display: var(--sun-display); }
.icon-moon { display: var(--moon-display); }

/* ═══════════════════════════════════════════════════════════════
   HERO SECTION — particles-js preserved
   ═══════════════════════════════════════════════════════════════ */
#particles-js {
  position: relative;
  width: 100%;
  min-height: 100vh;
  background: var(--hero-grad);
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

/* particles.js canvas */
#particles-js canvas {
  position: absolute;
  top: 0; left: 0;
  width: 100% !important;
  height: 100% !important;
  z-index: 0;
}

.hero-content {
  position: relative;
  z-index: 1;
  text-align: center;
  padding: 6rem 2rem 4rem;
  max-width: 800px;
}

.hero-greeting {
  font-size: 1.1rem;
  color: var(--text-secondary);
  margin-bottom: 0.5rem;
  font-weight: 400;
  letter-spacing: 0.05em;
}

.hero-title {
  font-size: clamp(2.8rem, 7vw, 5rem);
  font-weight: 800;
  line-height: 1.05;
  color: var(--text-primary);
  margin-bottom: 0.75rem;
}

.hero-title .name-highlight {
  background: linear-gradient(135deg, var(--accent) 0%, var(--accent-purple) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  font-size: 1.15rem;
  color: var(--text-secondary);
  margin-bottom: 2rem;
  font-weight: 400;
}

.hero-subtitle .typed-cursor { color: var(--accent); }

/* Hero social icons row */
.hero-socials {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
  margin-bottom: 2rem;
}

.hero-socials a {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 42px; height: 42px;
  border-radius: 10px;
  border: 1px solid var(--border-card);
  background: var(--bg-card);
  color: var(--text-secondary);
  font-size: 1.1rem;
  transition: all 0.25s;
}
.hero-socials a:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: var(--accent-glow);
  transform: translateY(-2px);
}

/* Hero CTA buttons */
.hero-ctas {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.65rem 1.5rem;
  background: var(--accent);
  color: #fff;
  border-radius: 8px;
  font-weight: 600;
  font-size: 0.9rem;
  border: 1px solid transparent;
  transition: all 0.25s;
}
.btn-primary:hover {
  background: transparent;
  border-color: var(--accent);
  color: var(--accent);
  transform: translateY(-2px);
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.65rem 1.5rem;
  background: transparent;
  color: var(--text-primary);
  border-radius: 8px;
  font-weight: 600;
  font-size: 0.9rem;
  border: 1px solid var(--border-card);
  transition: all 0.25s;
}
.btn-secondary:hover {
  border-color: var(--accent);
  color: var(--accent);
  transform: translateY(-2px);
}

/* Chevron down */
.hero-scroll-down {
  position: absolute;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%);
  z-index: 1;
  color: var(--text-muted);
  font-size: 1.4rem;
  animation: bounce 2s ease-in-out infinite;
}
@keyframes bounce {
  0%, 100% { transform: translateX(-50%) translateY(0); }
  50%       { transform: translateX(-50%) translateY(8px); }
}

/* ═══════════════════════════════════════════════════════════════
   SECTION SHARED
   ═══════════════════════════════════════════════════════════════ */
section {
  padding: 5rem 2rem;
}

.section-inner {
  max-width: 1100px;
  margin: 0 auto;
}

.section-title {
  text-align: center;
  font-size: clamp(1.8rem, 4vw, 2.4rem);
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 3rem;
  position: relative;
}
.section-title::after {
  content: '';
  display: block;
  width: 60px; height: 3px;
  background: linear-gradient(90deg, var(--accent), var(--accent-purple));
  border-radius: 2px;
  margin: 0.75rem auto 0;
}

/* ═══════════════════════════════════════════════════════════════
   ABOUT SECTION
   ═══════════════════════════════════════════════════════════════ */
#about { background: var(--bg-secondary); }

.about-grid {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 3rem;
  align-items: start;
}

.about-avatar-wrap {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1rem;
}

.about-avatar {
  width: 180px;
  height: 180px;
  border-radius: 50%;
  object-fit: cover;
  border: 3px solid var(--accent);
  box-shadow: 0 0 0 6px var(--accent-glow);
  transition: all 0.3s;
}
.about-avatar:hover {
  box-shadow: 0 0 0 10px var(--accent-glow);
  transform: scale(1.02);
}

.about-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.3rem 0.8rem;
  background: var(--accent-glow);
  border: 1px solid var(--accent);
  border-radius: 20px;
  font-size: 0.78rem;
  color: var(--accent);
  font-weight: 500;
}
.about-badge .dot {
  width: 7px; height: 7px;
  border-radius: 50%;
  background: var(--accent-green);
  animation: pulse 1.5s ease-in-out infinite;
}
@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50%       { opacity: 0.6; transform: scale(0.85); }
}

.about-text h2 {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 1rem;
  color: var(--text-primary);
}
.about-text p {
  color: var(--text-secondary);
  font-size: 0.97rem;
  line-height: 1.8;
  margin-bottom: 1rem;
}
.about-text strong { color: var(--text-primary); font-weight: 600; }

/* ── Tech Matrix ─────────────────────────────────────────────── */
.tech-matrix {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.25rem;
  margin-top: 3rem;
}

.tech-card {
  background: var(--bg-card);
  border: 1px solid var(--border-card);
  border-radius: 12px;
  padding: 1.5rem 1.25rem;
  transition: all 0.25s;
}
.tech-card:hover {
  border-color: var(--accent);
  transform: translateY(-3px);
  box-shadow: 0 8px 32px var(--accent-glow);
}

.tech-card h3 {
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--accent);
  margin-bottom: 1rem;
}

.tech-icons {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  margin-bottom: 0.75rem;
}

.tech-icons i {
  font-size: 1.75rem;
  transition: transform 0.2s;
}
.tech-icons i:hover { transform: scale(1.2); }

.tech-card p {
  font-size: 0.8rem;
  color: var(--text-muted);
  line-height: 1.6;
}

/* ═══════════════════════════════════════════════════════════════
   EXPERIENCE SECTION
   ═══════════════════════════════════════════════════════════════ */
#experience { background: var(--bg-primary); }

.exp-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.25rem;
}

.exp-card {
  background: var(--bg-card);
  border: 1px solid var(--border-card);
  border-radius: 12px;
  padding: 1.5rem;
  transition: all 0.25s;
}
.exp-card:hover {
  border-color: var(--accent);
  transform: translateY(-3px);
  box-shadow: 0 8px 32px var(--accent-glow);
}

.exp-card-header {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 0.75rem;
}

.exp-icon {
  width: 42px; height: 42px;
  border-radius: 10px;
  background: var(--accent-glow);
  border: 1px solid var(--accent);
  display: flex; align-items: center; justify-content: center;
  font-size: 1.25rem;
  flex-shrink: 0;
}

.exp-card-title { font-size: 0.97rem; font-weight: 700; color: var(--text-primary); }
.exp-card-org   { font-size: 0.82rem; color: var(--accent); font-weight: 600; }
.exp-card-date  { font-size: 0.78rem; color: var(--text-muted); margin-bottom: 0.75rem; }
.exp-card-desc  { font-size: 0.83rem; color: var(--text-secondary); line-height: 1.7; }

/* ═══════════════════════════════════════════════════════════════
   EDUCATION SECTION
   ═══════════════════════════════════════════════════════════════ */
#education { background: var(--bg-secondary); }

.edu-list {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  max-width: 750px;
  margin: 0 auto;
}

.edu-card {
  background: var(--bg-card);
  border: 1px solid var(--border-card);
  border-radius: 12px;
  padding: 1.5rem;
  display: flex;
  align-items: flex-start;
  gap: 1rem;
  transition: all 0.25s;
}
.edu-card:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
  box-shadow: 0 8px 32px var(--accent-glow);
}

.edu-icon {
  width: 48px; height: 48px;
  border-radius: 12px;
  background: var(--accent-glow);
  border: 1px solid var(--accent);
  display: flex; align-items: center; justify-content: center;
  font-size: 1.5rem;
  flex-shrink: 0;
}

.edu-body {}
.edu-degree { font-size: 1rem; font-weight: 700; color: var(--text-primary); }
.edu-inst   { font-size: 0.9rem; color: var(--accent); font-weight: 600; margin: 0.15rem 0; }
.edu-date   { font-size: 0.8rem; color: var(--text-muted); }
.edu-field  { font-size: 0.85rem; color: var(--text-secondary); margin-top: 0.35rem; }

/* ═══════════════════════════════════════════════════════════════
   PROJECTS SECTION — 2-column card grid
   ═══════════════════════════════════════════════════════════════ */
#projects { background: var(--bg-primary); }

.projects-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
}

/* Project card */
.project-card {
  background: var(--bg-card);
  border: 1px solid var(--border-card);
  border-radius: 14px;
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
  transition: all 0.3s;
  position: relative;
  overflow: hidden;
}
.project-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--accent), var(--accent-purple));
  opacity: 0;
  transition: opacity 0.3s;
}
.project-card:hover {
  border-color: var(--accent);
  transform: translateY(-4px);
  box-shadow: var(--card-shadow);
  background: var(--bg-card-hover);
}
.project-card:hover::before { opacity: 1; }

/* Card header */
.pc-header {
  display: flex;
  align-items: center;
  gap: 0.85rem;
}

.pc-avatar {
  width: 46px; height: 46px;
  border-radius: 12px;
  background: linear-gradient(135deg, var(--accent), var(--accent-purple));
  display: flex; align-items: center; justify-content: center;
  font-size: 1.4rem;
  flex-shrink: 0;
  font-weight: 700;
  color: #fff;
  box-shadow: 0 4px 12px var(--accent-glow);
}

.pc-title-wrap {}
.pc-title {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.2;
}
.pc-category {
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-top: 0.1rem;
  font-weight: 500;
}

/* Tech badge row */
.pc-tech {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}

.pc-tech-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  padding: 0.2rem 0.55rem;
  background: var(--tag-bg);
  color: var(--tag-text);
  border-radius: 5px;
  font-size: 0.73rem;
  font-weight: 600;
  border: 1px solid var(--border);
  white-space: nowrap;
}

.pc-tech-badge img {
  width: 14px; height: 14px;
  display: inline-block;
}

/* Narrative body */
.pc-body {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.75;
  flex: 1;
}

.pc-body .label {
  font-weight: 700;
  color: var(--accent);
}

/* Action links footer */
.pc-footer {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding-top: 0.5rem;
  border-top: 1px solid var(--border);
}

.pc-link {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--text-secondary);
  padding: 0.35rem 0.75rem;
  border-radius: 6px;
  border: 1px solid var(--border-card);
  background: transparent;
  transition: all 0.2s;
}
.pc-link:hover {
  color: var(--accent);
  border-color: var(--accent);
  background: var(--accent-glow);
}
.pc-link svg { width: 14px; height: 14px; }

.pc-link.live:hover {
  color: var(--accent-green);
  border-color: var(--accent-green);
  background: rgba(63, 185, 80, 0.1);
}

/* ═══════════════════════════════════════════════════════════════
   CONTACT SECTION
   ═══════════════════════════════════════════════════════════════ */
#contact { background: var(--bg-secondary); }

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

.contact-inner h2 {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 0.75rem;
}

.contact-inner p {
  color: var(--text-secondary);
  margin-bottom: 2rem;
  font-size: 0.97rem;
}

.contact-email-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.75rem 2rem;
  background: var(--accent);
  color: #fff;
  border-radius: 10px;
  font-weight: 700;
  font-size: 1rem;
  transition: all 0.25s;
  border: 1px solid transparent;
}
.contact-email-btn:hover {
  background: transparent;
  border-color: var(--accent);
  color: var(--accent);
  transform: translateY(-2px);
}

/* ═══════════════════════════════════════════════════════════════
   FOOTER
   ═══════════════════════════════════════════════════════════════ */
#site-footer {
  background: var(--footer-bg);
  border-top: 1px solid var(--border);
  padding: 3rem 2rem 1.5rem;
}

.footer-inner {
  max-width: 1100px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 2rem;
  align-items: center;
}

.footer-left {}
.footer-name {
  font-family: 'Fira Code', monospace;
  font-size: 1.2rem;
  font-weight: 700;
  color: #e6edf3;
  margin-bottom: 0.4rem;
}
.footer-tagline {
  font-size: 0.85rem;
  color: #8b949e;
  margin-bottom: 1.25rem;
}

.footer-socials {
  display: flex;
  gap: 0.6rem;
}
.footer-socials a {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px; height: 36px;
  border-radius: 8px;
  border: 1px solid rgba(255,255,255,0.1);
  color: #8b949e;
  font-size: 1rem;
  transition: all 0.2s;
}
.footer-socials a:hover {
  border-color: #58a6ff;
  color: #58a6ff;
  background: rgba(88,166,255,0.1);
}

.footer-right {}
.footer-avatar {
  width: 90px; height: 90px;
  border-radius: 50%;
  object-fit: cover;
  border: 2px solid #58a6ff;
  box-shadow: 0 0 0 4px rgba(88,166,255,0.2);
}

.footer-bottom {
  max-width: 1100px;
  margin: 2rem auto 0;
  padding-top: 1.25rem;
  border-top: 1px solid rgba(255,255,255,0.06);
  text-align: center;
}
.footer-bottom p {
  font-size: 0.82rem;
  color: #586069;
}
.footer-bottom .heart { color: #f85149; }

/* ═══════════════════════════════════════════════════════════════
   SIMPLE ICONS — CDN fix (use latest v9 instead of broken v3.4)
   ═══════════════════════════════════════════════════════════════ */
.si-icon {
  width: 18px; height: 18px;
  display: inline-block;
  vertical-align: middle;
}

/* Force devicon Next.js visible in both themes */
[data-theme="light"] .devicon-nextjs-plain { color: #000 !important; }
[data-theme="light"] .devicon-express-original { color: #000 !important; }
[data-theme="light"] .devicon-github-plain-wordmark { color: #000 !important; }

/* ═══════════════════════════════════════════════════════════════
   SCROLL-TRIGGERED FADE-IN
   ═══════════════════════════════════════════════════════════════ */
.fade-in {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
.fade-in.visible {
  opacity: 1;
  transform: none;
}

/* stagger children */
.fade-in:nth-child(2) { transition-delay: 0.1s; }
.fade-in:nth-child(3) { transition-delay: 0.2s; }
.fade-in:nth-child(4) { transition-delay: 0.3s; }
.fade-in:nth-child(5) { transition-delay: 0.4s; }
.fade-in:nth-child(6) { transition-delay: 0.5s; }

/* ═══════════════════════════════════════════════════════════════
   RESPONSIVE
   ═══════════════════════════════════════════════════════════════ */

/* Tablet */
@media (max-width: 900px) {
  .tech-matrix  { grid-template-columns: repeat(2, 1fr); }
  .exp-grid     { grid-template-columns: repeat(2, 1fr); }
  .projects-grid { grid-template-columns: 1fr; }
  .about-grid   { grid-template-columns: 1fr; }
  .about-avatar-wrap { flex-direction: row; justify-content: flex-start; }
  .footer-inner { grid-template-columns: 1fr; }
  .footer-right { display: none; }
}

/* Mobile */
@media (max-width: 600px) {
  .nav-links a { display: none; }
  .nav-links a:last-of-type { display: flex; } /* keep theme toggle visible */
  #theme-toggle { display: flex; }

  .tech-matrix  { grid-template-columns: 1fr; }
  .exp-grid     { grid-template-columns: 1fr; }
  .hero-title   { font-size: 2.4rem; }
  section       { padding: 3.5rem 1.25rem; }
}