/* =============================================
   Pavithran M – Portfolio Stylesheet
   ============================================= */

/* ===== Design Tokens ===== */
:root {
  /* Colors – Dark theme (default) */
  --bg: #0a0e17;
  --bg-card: rgba(17, 24, 39, 0.7);
  --bg-nav: rgba(10, 14, 23, 0.88);
  --text: #e2e8f0;
  --text-muted: #94a3b8;
  --accent: #60a5fa;
  --accent-secondary: #a78bfa;
  --accent-glow: rgba(96, 165, 250, 0.18);
  --accent-gradient: linear-gradient(135deg, #60a5fa, #a78bfa);
  --border: rgba(255, 255, 255, 0.06);
  --shadow: 0 4px 24px rgba(0, 0, 0, 0.4);
  --shadow-hover: 0 12px 40px rgba(0, 0, 0, 0.55);
  --dot-color: rgba(255, 255, 255, 0.03);

  /* Spacing & Layout */
  --radius: 20px;
  --radius-sm: 12px;
  --nav-height: 64px;

  /* Typography */
  --font-sans: 'Inter', 'Segoe UI', system-ui, -apple-system, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Consolas', monospace;
}

/* ===== Light Theme Tokens ===== */
[data-theme="light"] {
  --bg: #f8fafc;
  --bg-card: rgba(255, 255, 255, 0.75);
  --bg-nav: rgba(248, 250, 252, 0.82);
  --text: #0f172a;
  --text-muted: #64748b;
  --accent: #3b82f6;
  --accent-secondary: #8b5cf6;
  --accent-glow: rgba(59, 130, 246, 0.2);
  --accent-gradient: linear-gradient(135deg, #3b82f6, #8b5cf6);
  --border: rgba(0, 0, 0, 0.06);
  --shadow: 0 4px 24px rgba(0, 0, 0, 0.05);
  --shadow-hover: 0 12px 40px rgba(0, 0, 0, 0.1);
  --dot-color: rgba(0, 0, 0, 0.04);
}

/* Respect system preference for light mode */
@media (prefers-color-scheme: light) {
  :root:not([data-theme="dark"]) {
    --bg: #f8fafc;
    --bg-card: rgba(255, 255, 255, 0.75);
    --bg-nav: rgba(248, 250, 252, 0.82);
    --text: #0f172a;
    --text-muted: #64748b;
    --accent: #3b82f6;
    --accent-secondary: #8b5cf6;
    --accent-glow: rgba(59, 130, 246, 0.2);
    --accent-gradient: linear-gradient(135deg, #3b82f6, #8b5cf6);
    --border: rgba(0, 0, 0, 0.06);
    --shadow: 0 4px 24px rgba(0, 0, 0, 0.05);
    --shadow-hover: 0 12px 40px rgba(0, 0, 0, 0.1);
    --dot-color: rgba(0, 0, 0, 0.04);
  }
}

/* ===== Reset & Base ===== */
*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--nav-height) + 1rem);
}

body {
  font-family: var(--font-sans);
  margin: 0;
  padding: 0;
  line-height: 1.7;
  background:
    radial-gradient(circle, var(--dot-color) 1px, transparent 1px) 0 0 / 24px 24px,
    var(--bg);
  color: var(--text);
  transition: background 0.35s ease, color 0.35s ease;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Custom selection */
::selection {
  background: var(--accent);
  color: #fff;
}

/* Custom scrollbar */
::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background: var(--bg);
}

::-webkit-scrollbar-thumb {
  background: var(--accent-glow);
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--accent);
}

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

a {
  color: var(--accent);
  text-decoration: none;
  transition: color 0.2s;
}

a:hover {
  text-decoration: underline;
}

/* ===== Accessibility ===== */
.skip-link {
  position: absolute;
  top: -100%;
  left: 1rem;
  z-index: 200;
  padding: 0.5rem 1rem;
  background: var(--accent);
  color: #fff;
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: 0.9rem;
  text-decoration: none;
  transition: top 0.2s;
}

.skip-link:focus {
  top: 0.5rem;
}

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

:focus:not(:focus-visible) {
  outline: none;
}

/* ===== Reduced Motion ===== */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }

  .fade-up {
    opacity: 1;
    transform: none;
  }
}

/* ===== Navbar ===== */
.navbar {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--nav-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 clamp(1rem, 4vw, 2.5rem);
  background: var(--bg-nav);
  backdrop-filter: blur(16px) saturate(180%);
  -webkit-backdrop-filter: blur(16px) saturate(180%);
  border-bottom: 1px solid var(--border);
  transition: background 0.35s ease, box-shadow 0.35s ease;
}

.navbar.scrolled {
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
}

.navbar .logo {
  font-weight: 800;
  font-size: 1.2rem;
  color: var(--text);
  text-decoration: none;
  letter-spacing: -0.02em;
}

.navbar .logo span {
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 1.25rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-links a {
  color: var(--text-muted);
  font-size: 0.9rem;
  font-weight: 500;
  text-decoration: none;
  padding: 0.35rem 0;
  position: relative;
  transition: color 0.2s;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--accent-gradient);
  border-radius: 2px;
  transform: scaleX(0);
  transition: transform 0.25s cubic-bezier(0.34, 1.56, 0.64, 1);
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--accent);
  text-decoration: none;
}

.nav-links a:hover::after,
.nav-links a.active::after {
  transform: scaleX(1);
}

.theme-toggle {
  background: none;
  border: 1px solid var(--border);
  border-radius: 50%;
  width: 38px;
  height: 38px;
  cursor: pointer;
  font-size: 1.1rem;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.25s, border-color 0.25s, transform 0.25s;
  color: var(--text);
}

/* Default (dark): show sun, hide moon */
.theme-toggle .icon-moon { display: none; }
.theme-toggle .icon-sun { display: block; }

/* Light mode: show moon, hide sun */
[data-theme="light"] .theme-toggle .icon-sun { display: none; }
[data-theme="light"] .theme-toggle .icon-moon { display: block; }

@media (prefers-color-scheme: light) {
  :root:not([data-theme="dark"]) .theme-toggle .icon-sun { display: none; }
  :root:not([data-theme="dark"]) .theme-toggle .icon-moon { display: block; }
}

.theme-toggle:hover {
  background: var(--accent-glow);
  border-color: var(--accent);
  transform: rotate(20deg);
}

/* Hamburger (mobile) */
.nav-hamburger {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  color: var(--text);
  padding: 0.25rem;
  line-height: 0;
}

@media (max-width: 640px) {
  .nav-hamburger {
    display: block;
  }

  .nav-links {
    display: none;
    flex-direction: column;
    position: absolute;
    top: var(--nav-height);
    left: 0;
    right: 0;
    background: var(--bg-nav);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
    padding: 1rem 2rem;
    gap: 0.75rem;
  }

  .nav-links.open {
    display: flex;
  }
}

/* ===== Hero ===== */
.hero {
  position: relative;
  text-align: center;
  padding: 6rem 1.5rem 4rem;
  background:
    radial-gradient(ellipse 80% 50% at 50% -20%, rgba(59, 130, 246, 0.12), transparent),
    radial-gradient(ellipse 60% 40% at 80% 60%, rgba(139, 92, 246, 0.08), transparent),
    radial-gradient(ellipse 50% 50% at 20% 80%, rgba(59, 130, 246, 0.06), transparent);
  overflow: hidden;
}

/* Floating orb decoration */
.hero::before {
  content: '';
  position: absolute;
  top: -120px;
  right: -80px;
  width: 350px;
  height: 350px;
  border-radius: 50%;
  background: var(--accent-gradient);
  opacity: 0.06;
  filter: blur(60px);
  pointer-events: none;
  animation: float-orb 8s ease-in-out infinite;
}

.hero::after {
  content: '';
  position: absolute;
  bottom: -100px;
  left: -60px;
  width: 280px;
  height: 280px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--accent-secondary), var(--accent));
  opacity: 0.05;
  filter: blur(50px);
  pointer-events: none;
  animation: float-orb 10s ease-in-out infinite reverse;
}

@keyframes float-orb {
  0%, 100% { transform: translateY(0) scale(1); }
  50% { transform: translateY(-30px) scale(1.05); }
}

.hero h1 {
  position: relative;
  font-size: clamp(2.2rem, 5vw, 3.2rem);
  font-weight: 800;
  margin: 0 0 0.5rem;
  letter-spacing: -0.03em;
  line-height: 1.2;
  text-wrap: balance;
}

.hero h1 span {
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero .subtitle {
  position: relative;
  font-size: 1.1rem;
  color: var(--text-muted);
  margin: 0 0 2rem;
  max-width: 650px;
  margin-inline: auto;
  line-height: 1.6;
}

.hero-cta {
  position: relative;
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
}

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 1.75rem;
  border-radius: 50px;
  font-weight: 600;
  font-size: 0.95rem;
  text-decoration: none;
  transition: transform 0.25s cubic-bezier(0.34, 1.56, 0.64, 1), box-shadow 0.25s;
  position: relative;
  overflow: hidden;
}

.btn:hover {
  transform: translateY(-3px);
  text-decoration: none;
}

.btn:active {
  transform: translateY(-1px);
}

.btn-primary {
  background: var(--accent-gradient);
  color: #fff;
  box-shadow: 0 4px 16px var(--accent-glow);
  border: none;
}

.btn-primary:hover {
  box-shadow: 0 8px 28px rgba(59, 130, 246, 0.3);
}

.btn-outline {
  background: transparent;
  color: var(--accent);
  border: 1.5px solid var(--accent);
}

.btn-outline:hover {
  background: var(--accent-glow);
  border-color: var(--accent-secondary);
  color: var(--accent-secondary);
}

/* ===== Section Cards ===== */
.card-section {
  max-width: 860px;
  margin: 2.5rem auto;
  padding: 2.5rem;
  background: var(--bg-card);
  backdrop-filter: blur(12px) saturate(150%);
  -webkit-backdrop-filter: blur(12px) saturate(150%);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  transition: transform 0.35s cubic-bezier(0.34, 1.56, 0.64, 1), box-shadow 0.35s ease;
  position: relative;
}

/* Subtle gradient top-border accent */
.card-section::before {
  content: '';
  position: absolute;
  top: 0;
  left: 2rem;
  right: 2rem;
  height: 2px;
  background: var(--accent-gradient);
  border-radius: 2px;
  opacity: 0;
  transition: opacity 0.35s;
}

.card-section:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-hover);
}

.card-section:hover::before {
  opacity: 1;
}

.card-section h2 {
  color: var(--text);
  margin-top: 0;
  margin-bottom: 1.25rem;
  text-align: center;
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.6rem;
}

/* Section header SVG icons */
.section-icon {
  width: 1.3em;
  height: 1.3em;
  flex-shrink: 0;
  stroke: url(#icon-gradient);
  /* Fallback for browsers that don't support SVG gradient stroke */
  color: var(--accent);
}

/* ===== Utilities ===== */
.center {
  text-align: center;
}

.section-subtitle {
  text-align: center;
  color: var(--text-muted);
  margin-bottom: 1.25rem;
}

.mt-1 {
  margin-top: 1rem;
}

.contact-links {
  margin-top: 1.25rem;
  color: var(--text-muted);
  font-size: 0.9rem;
}

/* ===== Tech Stack ===== */
.tech-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
}

@media (max-width: 580px) {
  .tech-grid {
    grid-template-columns: 1fr;
  }
}

.tech-category {
  padding: 1.25rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: var(--bg);
  transition: border-color 0.3s, box-shadow 0.3s;
}

.tech-category:hover {
  border-color: var(--accent);
  box-shadow: 0 4px 20px var(--accent-glow);
}

.tech-category-label {
  font-weight: 700;
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--accent);
  margin-bottom: 0.75rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border);
}

.tech-pills {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
}

.pill {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.4rem 0.9rem;
  border-radius: 50px;
  font-size: 0.82rem;
  font-weight: 600;
  font-family: var(--font-mono);
  border: 1px solid var(--border);
  background: var(--bg-card);
  color: var(--text);
  transition: transform 0.25s cubic-bezier(0.34, 1.56, 0.64, 1), box-shadow 0.25s, border-color 0.25s;
}

.pill:hover {
  transform: translateY(-3px);
  box-shadow: 0 6px 16px var(--accent-glow);
  border-color: var(--accent);
}

.pill-icon {
  display: none;
}

/* ===== SVG Icon Utilities ===== */
.btn-icon {
  vertical-align: -0.15em;
  flex-shrink: 0;
}

.project-icon {
  vertical-align: -0.2em;
  opacity: 0.7;
  transition: opacity 0.2s;
}

.project-card:hover .project-icon {
  opacity: 1;
}

.inline-icon {
  vertical-align: -0.15em;
}

.heart-icon {
  color: #ef4444;
}

.footer-links svg {
  transition: transform 0.2s;
}

.footer-links a:hover svg {
  transform: translateY(-2px);
}

/* ===== Contact Buttons ===== */
.contact-buttons {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.contact-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.65rem 1.4rem;
  border-radius: 10px;
  font-size: 0.9rem;
  font-weight: 600;
  font-family: var(--font-sans);
  letter-spacing: 0.01em;
  text-decoration: none;
  border: 1px solid var(--border);
  background: var(--bg-card);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  color: var(--text);
  transition: transform 0.25s cubic-bezier(0.34, 1.56, 0.64, 1),
              box-shadow 0.25s, border-color 0.25s, color 0.25s;
}

.contact-btn:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.15);
}

.contact-btn.linkedin:hover {
  border-color: #0a66c2;
  color: #0a66c2;
  box-shadow: 0 8px 24px rgba(10, 102, 194, 0.2);
}

.contact-btn.youtube:hover {
  border-color: #ff0000;
  color: #ff0000;
  box-shadow: 0 8px 24px rgba(255, 0, 0, 0.15);
}

.contact-btn.email:hover {
  border-color: var(--accent);
  color: var(--accent);
  box-shadow: 0 8px 24px var(--accent-glow);
}

/* ===== Project Cards ===== */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.5rem;
}

.project-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 1.5rem;
  transition: transform 0.3s cubic-bezier(0.34, 1.56, 0.64, 1), box-shadow 0.3s;
  position: relative;
  overflow: hidden;
}

/* Gradient top accent bar */
.project-card::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--accent-gradient);
  opacity: 0;
  transition: opacity 0.3s;
}

.project-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-hover);
}

.project-card:hover::after {
  opacity: 1;
}

.project-card h3 {
  margin: 0 0 0.5rem;
  font-size: 1.08rem;
}

.project-card h3 a {
  color: var(--text);
  text-decoration: none;
  transition: color 0.2s;
}

.project-card h3 a:hover {
  color: var(--accent);
  text-decoration: none;
}

.project-card p {
  font-size: 0.88rem;
  color: var(--text-muted);
  margin: 0 0 0.75rem;
  line-height: 1.55;
}

.project-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-top: auto;
}

.project-tag {
  font-size: 0.72rem;
  font-weight: 600;
  font-family: var(--font-mono);
  padding: 0.25rem 0.65rem;
  border-radius: 50px;
  background: var(--accent-glow);
  color: var(--accent);
  transition: background 0.2s, transform 0.2s;
}

.project-tag:hover {
  background: var(--accent);
  color: #fff;
  transform: scale(1.05);
}

/* ===== Timeline ===== */
.timeline {
  position: relative;
  padding-left: 2rem;
  margin-top: 1rem;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 7px;
  top: 4px;
  bottom: 4px;
  width: 2px;
  background: var(--accent);
  opacity: 0.3;
  border-radius: 2px;
}

.timeline-item {
  position: relative;
  margin-bottom: 1.5rem;
}

.timeline-item:last-child {
  margin-bottom: 0;
}

.timeline-item::before {
  content: '';
  position: absolute;
  left: -2rem;
  top: 6px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--accent-gradient);
  border: 2px solid var(--bg-card);
  box-shadow: 0 0 0 4px var(--accent-glow);
  transition: box-shadow 0.3s;
}

.timeline-item:hover::before {
  box-shadow: 0 0 0 6px var(--accent-glow), 0 0 16px var(--accent-glow);
}

.timeline-date {
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.timeline-title {
  font-weight: 700;
  font-size: 1rem;
  margin: 0.15rem 0;
}

.timeline-desc {
  font-size: 0.88rem;
  color: var(--text-muted);
  margin: 0;
  line-height: 1.55;
}

.timeline-list {
  list-style: none;
  padding: 0;
  margin: 0.35rem 0 0;
}

.timeline-list li {
  position: relative;
  padding-left: 1.2rem;
  font-size: 0.88rem;
  color: var(--text-muted);
  line-height: 1.65;
  margin-bottom: 0.25rem;
}

.timeline-list li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0.55em;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent-gradient);
}

/* ===== Certifications ===== */
.cert-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1rem;
  margin-top: 1rem;
}

.cert-card {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 1rem 1.2rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: var(--bg-card);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  transition: transform 0.25s cubic-bezier(0.34, 1.56, 0.64, 1), box-shadow 0.25s, border-color 0.25s;
}

.cert-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 24px var(--accent-glow);
  border-color: var(--accent);
}

.cert-icon {
  flex-shrink: 0;
  color: var(--accent);
}

.cert-card span {
  font-size: 0.9rem;
  font-weight: 600;
}

/* ===== Awards ===== */
.awards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1rem;
  margin-top: 1rem;
}

.award-card {
  text-align: center;
  padding: 1.4rem 1rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: var(--bg-card);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  transition: transform 0.25s cubic-bezier(0.34, 1.56, 0.64, 1), box-shadow 0.25s, border-color 0.25s;
  position: relative;
  overflow: hidden;
}

.award-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--accent-gradient);
  opacity: 0;
  transition: opacity 0.3s;
}

.award-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 24px var(--accent-glow);
  border-color: var(--accent);
}

.award-card:hover::before {
  opacity: 1;
}

.award-title {
  font-weight: 700;
  font-size: 1rem;
  margin-bottom: 0.3rem;
}

.award-years {
  font-size: 0.82rem;
  color: var(--accent);
  font-family: var(--font-mono);
  letter-spacing: 0.02em;
}

/* ===== GitHub Stats ===== */
.stats-row {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  justify-content: center;
  align-items: center;
}

.stats-row img {
  border-radius: var(--radius-sm);
  max-height: 195px;
}

/* ===== Footer ===== */
.footer {
  text-align: center;
  padding: 3rem 1rem;
  margin-top: 4rem;
  position: relative;
  color: var(--text-muted);
  font-size: 0.85rem;
}

/* Gradient divider — replaces plain border-top */
.footer::before {
  content: '';
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: min(300px, 60%);
  height: 2px;
  background: var(--accent-gradient);
  border-radius: 2px;
  opacity: 0.5;
}

.footer-links {
  display: flex;
  justify-content: center;
  gap: 1.5rem;
  margin-bottom: 1.25rem;
}

.footer-links a {
  color: var(--text-muted);
  font-size: 1.35rem;
  transition: color 0.2s, transform 0.25s;
  display: inline-block;
}

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

.footer p {
  margin: 0.3rem 0;
}

/* ===== Responsive ===== */
@media (max-width: 900px) {
  .card-section {
    margin: 1.5rem 1rem;
  }
}

/* ===== Scroll Animations ===== */
.fade-up {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.7s cubic-bezier(0.16, 1, 0.3, 1), transform 0.7s cubic-bezier(0.16, 1, 0.3, 1);
}

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

/* Staggered animation delay for child cards */
.fade-up:nth-child(2) { transition-delay: 0.08s; }
.fade-up:nth-child(3) { transition-delay: 0.16s; }
.fade-up:nth-child(4) { transition-delay: 0.24s; }
.fade-up:nth-child(5) { transition-delay: 0.32s; }
.fade-up:nth-child(6) { transition-delay: 0.4s; }

/* ===== Back to Top ===== */
.back-to-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  z-index: 90;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  border: 1px solid var(--border);
  background: var(--bg-card);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  color: var(--accent);
  font-size: 1.3rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow);
  opacity: 0;
  pointer-events: none;
  transform: translateY(10px);
  transition: opacity 0.3s, transform 0.3s, background 0.2s;
}

.back-to-top.show {
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0);
}

.back-to-top:hover {
  background: var(--accent-gradient);
  color: #fff;
  border-color: transparent;
}

/* ===== Print ===== */
@media print {
  .navbar,
  .back-to-top,
  .theme-toggle,
  .nav-hamburger,
  .hero-cta,
  .contact-buttons,
  .stats-row,
  .footer-links {
    display: none !important;
  }

  body {
    background: #fff;
    color: #000;
    font-size: 11pt;
    line-height: 1.5;
  }

  .card-section {
    background: none;
    border: 1px solid #ddd;
    box-shadow: none;
    backdrop-filter: none;
    break-inside: avoid;
    margin: 1rem 0;
    padding: 1rem;
  }

  .card-section::before {
    display: none;
  }

  .card-section:hover {
    transform: none;
    box-shadow: none;
  }

  .hero {
    background: none;
    padding: 1.5rem 0;
  }

  h1, h2 {
    color: #000;
  }

  a {
    color: #000;
    text-decoration: underline;
  }

  a::after {
    content: ' (' attr(href) ')';
    font-size: 0.8em;
    color: #555;
  }

  .pill {
    border-color: #ccc;
    background: #f5f5f5;
  }

  .project-tag {
    background: #eee;
    color: #333;
  }

  .fade-up {
    opacity: 1;
    transform: none;
  }

  .footer {
    border-top: 1px solid #ddd;
  }
}