/* ==========================================================================
   Manoj Kumar — Portfolio Stylesheet
   Handcrafted CSS3. No frameworks.
   ========================================================================== */

/* ---------- 1. Design Tokens ---------- */
:root {
  --bg: #0B1220;
  --surface: #111827;
  --card: #1E293B;
  --primary: #3B82F6;
  --secondary: #06B6D4;
  --text: #F8FAFC;
  --muted: #94A3B8;
  --border: rgba(255, 255, 255, 0.08);

  --radius: 16px;
  --radius-sm: 10px;
  --max-width: 1200px;

  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.25);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.35);
  --shadow-lg: 0 20px 60px rgba(0, 0, 0, 0.45);

  --gradient-primary: linear-gradient(135deg, var(--primary), var(--secondary));
  --gradient-surface: linear-gradient(180deg, rgba(59, 130, 246, 0.08), transparent);

  --font-heading: 'Plus Jakarta Sans', 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;

  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;
  --transition-slow: 450ms cubic-bezier(0.16, 1, 0.3, 1);

  --header-height: 76px;
  color-scheme: dark;
}

:root[data-theme="light"] {
  --bg: #F8FAFC;
  --surface: #FFFFFF;
  --card: #FFFFFF;
  --primary: #2563EB;
  --secondary: #0891B2;
  --text: #0B1220;
  --muted: #475569;
  --border: rgba(15, 23, 42, 0.09);

  --shadow-sm: 0 2px 8px rgba(15, 23, 42, 0.06);
  --shadow-md: 0 8px 24px rgba(15, 23, 42, 0.08);
  --shadow-lg: 0 20px 50px rgba(15, 23, 42, 0.12);
  color-scheme: light;
}

@media (prefers-color-scheme: light) {
  :root:not([data-theme="dark"]) {
    --bg: #F8FAFC;
    --surface: #FFFFFF;
    --card: #FFFFFF;
    --primary: #2563EB;
    --secondary: #0891B2;
    --text: #0B1220;
    --muted: #475569;
    --border: rgba(15, 23, 42, 0.09);
    --shadow-sm: 0 2px 8px rgba(15, 23, 42, 0.06);
    --shadow-md: 0 8px 24px rgba(15, 23, 42, 0.08);
    --shadow-lg: 0 20px 50px rgba(15, 23, 42, 0.12);
    color-scheme: light;
  }
}

/* ---------- 2. Reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  transition: background-color var(--transition-base), color var(--transition-base);
}
img { max-width: 100%; display: block; }
ul, ol { list-style: none; margin: 0; padding: 0; }
a { color: inherit; text-decoration: none; }
button { font: inherit; color: inherit; background: none; border: none; cursor: pointer; }
h1, h2, h3, h4 { font-family: var(--font-heading); font-weight: 700; line-height: 1.2; margin: 0; }
p { margin: 0; }

/* Respect 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;
    scroll-behavior: auto !important;
  }
}

/* Focus states */
a:focus-visible,
button:focus-visible,
input:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 3px;
  border-radius: 4px;
}

/* ---------- 3. Layout Helpers ---------- */
.container {
  max-width: var(--max-width);
  margin-inline: auto;
  padding-inline: 24px;
}
.section-padding { padding-block: 112px; }
.alt-bg { background: var(--surface); }

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--primary);
  color: #fff;
  padding: 12px 20px;
  border-radius: 0 0 8px 0;
  z-index: 1000;
}
.skip-link:focus { left: 0; }

.section-eyebrow {
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 0.8rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--secondary);
  margin-bottom: 12px;
}
.section-heading {
  font-size: clamp(1.8rem, 3vw, 2.5rem);
  margin-bottom: 16px;
  letter-spacing: -0.02em;
}
.section-subtext {
  color: var(--muted);
  max-width: 640px;
  font-size: 1.05rem;
  margin-bottom: 48px;
}
.subsection-heading {
  font-family: var(--font-heading);
  font-size: 1.4rem;
  margin-top: 64px;
  margin-bottom: 8px;
}

/* Scroll-triggered fade-in */
.fade-in {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity var(--transition-slow), transform var(--transition-slow);
}
.fade-in.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* ---------- 4. Scroll Progress Bar ---------- */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  width: 0%;
  background: var(--gradient-primary);
  z-index: 1100;
  transition: width 80ms linear;
}

/* ---------- 5. Header / Navigation ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  height: var(--header-height);
  display: flex;
  align-items: center;
  background: color-mix(in srgb, var(--bg) 78%, transparent);
  backdrop-filter: blur(14px) saturate(140%);
  -webkit-backdrop-filter: blur(14px) saturate(140%);
  border-bottom: 1px solid transparent;
  transition: border-color var(--transition-base), background-color var(--transition-base);
}
.site-header.is-scrolled { border-bottom-color: var(--border); }

.navbar {
  max-width: var(--max-width);
  width: 100%;
  margin-inline: auto;
  padding-inline: 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-heading);
  font-weight: 700;
}
.brand-mark {
  display: grid;
  place-items: center;
  width: 38px;
  height: 38px;
  border-radius: 10px;
  background: var(--gradient-primary);
  color: #fff;
  font-size: 0.85rem;
  letter-spacing: 0.02em;
}
.brand-name { font-size: 1.05rem; }

.nav-menu {
  display: flex;
  align-items: center;
  gap: 8px;
}
.nav-link {
  position: relative;
  display: inline-block;
  padding: 8px 14px;
  font-size: 0.95rem;
  color: var(--muted);
  font-weight: 500;
  border-radius: 8px;
  transition: color var(--transition-fast), background-color var(--transition-fast);
}
.nav-link:hover { color: var(--text); background: var(--card); }
.nav-link.is-active { color: var(--text); }
.nav-link.is-active::after {
  content: "";
  position: absolute;
  left: 14px;
  right: 14px;
  bottom: 2px;
  height: 2px;
  background: var(--gradient-primary);
  border-radius: 2px;
}

.nav-theme { margin-left: 8px; }
.theme-toggle {
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
  border-radius: 10px;
  border: 1px solid var(--border);
  color: var(--text);
  transition: background-color var(--transition-fast), border-color var(--transition-fast);
}
.theme-toggle:hover { background: var(--card); }
.icon-moon { display: none; }
:root[data-theme="light"] .icon-sun { display: none; }
:root[data-theme="light"] .icon-moon { display: block; }

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  border-radius: 8px;
}
.nav-toggle-bar {
  width: 20px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: transform var(--transition-fast), opacity var(--transition-fast);
}
.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ---------- 6. Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 13px 24px;
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: 0.95rem;
  border-radius: var(--radius-sm);
  transition: transform var(--transition-fast), box-shadow var(--transition-fast), background-color var(--transition-fast), border-color var(--transition-fast);
  white-space: nowrap;
}
.btn-primary {
  background: var(--gradient-primary);
  color: #fff;
  box-shadow: var(--shadow-md);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: var(--shadow-lg); }
.btn-secondary {
  background: transparent;
  color: var(--text);
  border: 1px solid var(--border);
}
.btn-secondary:hover { background: var(--card); transform: translateY(-2px); }

/* ---------- 7. Hero ---------- */
.hero {
  position: relative;
  padding-top: calc(112px + var(--header-height));
  overflow: hidden;
}
.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(560px circle at 85% 10%, rgba(59, 130, 246, 0.18), transparent 60%),
    radial-gradient(480px circle at 10% 30%, rgba(6, 182, 212, 0.12), transparent 60%);
  pointer-events: none;
}
.hero-grid {
  position: relative;
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 64px;
  align-items: center;
}
.hero-eyebrow {
  color: var(--secondary);
  font-weight: 600;
  font-size: 1rem;
  margin-bottom: 12px;
}
.hero-name {
  font-size: clamp(2.6rem, 5.5vw, 4.2rem);
  letter-spacing: -0.03em;
  background: linear-gradient(135deg, var(--text), var(--text) 55%, var(--primary));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.hero-title {
  font-family: var(--font-heading);
  font-size: clamp(1.15rem, 2vw, 1.5rem);
  font-weight: 600;
  color: var(--text);
  margin-top: 10px;
}
.hero-tagline {
  color: var(--muted);
  font-size: 1.1rem;
  max-width: 560px;
  margin-top: 20px;
}
.hero-intro {
  color: var(--muted);
  font-size: 1rem;
  max-width: 620px;
  margin-top: 18px;
  line-height: 1.75;
}
.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 34px;
}
.hero-socials {
  display: flex;
  gap: 16px;
  margin-top: 32px;
}
.hero-socials a {
  display: grid;
  place-items: center;
  width: 42px;
  height: 42px;
  border-radius: 10px;
  border: 1px solid var(--border);
  color: var(--muted);
  transition: color var(--transition-fast), border-color var(--transition-fast), transform var(--transition-fast);
}
.hero-socials a:hover { color: var(--primary); border-color: var(--primary); transform: translateY(-2px); }

.hero-stats {
  display: flex;
  gap: 40px;
  margin-top: 48px;
  padding-top: 32px;
  border-top: 1px solid var(--border);
}
.stat-number {
  font-family: var(--font-heading);
  font-size: 2.2rem;
  font-weight: 800;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.stat-label {
  color: var(--muted);
  font-size: 0.85rem;
  margin-top: 4px;
}

.hero-visual { display: grid; place-items: center; }
.hero-illustration {
  width: 100%;
  max-width: 440px;
  filter: drop-shadow(0 24px 48px rgba(59, 130, 246, 0.2));
}

.scroll-cue {
  position: absolute;
  bottom: 28px;
  left: 50%;
  transform: translateX(-50%);
  color: var(--muted);
  animation: bounce 2.2s ease-in-out infinite;
}
@keyframes bounce {
  0%, 100% { transform: translate(-50%, 0); }
  50% { transform: translate(-50%, 8px); }
}
@media (prefers-reduced-motion: reduce) {
  .scroll-cue { animation: none; }
}

/* ---------- 8. About ---------- */
.about-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr;
  gap: 56px;
  align-items: start;
}
.about-copy p { color: var(--muted); margin-bottom: 20px; font-size: 1.03rem; }
.about-copy p:last-child { margin-bottom: 0; }

.competencies {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
  box-shadow: var(--shadow-sm);
}
.competencies-title {
  font-size: 1.05rem;
  margin-bottom: 20px;
}
.competency-list { display: flex; flex-direction: column; gap: 16px; }
.competency-list li {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 0.95rem;
  color: var(--text);
}
.competency-icon { font-size: 1.1rem; }

/* ---------- 9. Skills ---------- */
.skills-groups {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 28px;
}
.skill-group {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  transition: border-color var(--transition-base), transform var(--transition-base);
}
.skill-group:hover { border-color: color-mix(in srgb, var(--primary) 40%, var(--border)); }
.skill-group-title {
  font-size: 1rem;
  margin-bottom: 16px;
  color: var(--text);
}
.pill-list { display: flex; flex-wrap: wrap; gap: 8px; }
.pill {
  font-size: 0.82rem;
  font-weight: 500;
  padding: 7px 13px;
  border-radius: 999px;
  background: color-mix(in srgb, var(--primary) 12%, transparent);
  color: var(--primary);
  border: 1px solid color-mix(in srgb, var(--primary) 22%, transparent);
  transition: transform var(--transition-fast);
}
.pill:hover { transform: translateY(-1px); }

/* ---------- 10. Experience Timeline ---------- */
.timeline {
  position: relative;
  max-width: 880px;
  margin-inline: auto;
  padding-left: 32px;
  border-left: 2px solid var(--border);
}
.timeline-item { position: relative; padding-bottom: 48px; }
.timeline-item:last-child { padding-bottom: 0; }
.timeline-marker {
  position: absolute;
  left: -39px;
  top: 6px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--gradient-primary);
  border: 3px solid var(--bg);
  box-shadow: 0 0 0 2px var(--primary);
}
.timeline-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 32px;
  box-shadow: var(--shadow-sm);
  position: relative;
}
.badge-current {
  position: absolute;
  top: 24px;
  right: 28px;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: #fff;
  background: var(--gradient-primary);
  padding: 5px 12px;
  border-radius: 999px;
}
.timeline-role { font-size: 1.25rem; margin-bottom: 4px; }
.timeline-org { color: var(--secondary); font-weight: 600; font-size: 0.95rem; }
.timeline-org a {
  color: inherit;
  border-bottom: 1px solid transparent;
  transition: color var(--transition-fast), border-color var(--transition-fast);
}
.timeline-org a:hover { color: var(--primary); border-bottom-color: var(--primary); }
.timeline-dates { color: var(--muted); font-size: 0.85rem; margin-top: 2px; margin-bottom: 18px; }
.timeline-highlights { display: flex; flex-direction: column; gap: 10px; margin-bottom: 22px; }
.timeline-highlights li {
  position: relative;
  padding-left: 20px;
  color: var(--muted);
  font-size: 0.95rem;
  line-height: 1.6;
}
.timeline-highlights li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 9px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--secondary);
}
.tech-badges { display: flex; flex-wrap: wrap; gap: 8px; }
.tech-badges li {
  font-size: 0.78rem;
  font-weight: 600;
  padding: 5px 11px;
  border-radius: 6px;
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--muted);
}

/* ---------- 11. Projects ---------- */
.project-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 28px;
}
.featured-grid { grid-template-columns: repeat(auto-fit, minmax(380px, 1fr)); margin-bottom: 8px; }

.project-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition-base), box-shadow var(--transition-base), border-color var(--transition-base);
  display: flex;
  flex-direction: column;
}
.project-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
  border-color: color-mix(in srgb, var(--primary) 35%, var(--border));
}
.project-icon {
  display: grid;
  place-items: center;
  width: 52px;
  height: 52px;
  border-radius: var(--radius-sm);
  background: var(--gradient-surface);
  color: var(--primary);
  margin-bottom: 20px;
}
.project-title { font-size: 1.15rem; margin-bottom: 10px; }
.project-desc { color: var(--muted); font-size: 0.93rem; margin-bottom: 16px; }
.project-features { display: flex; flex-direction: column; gap: 8px; margin-bottom: 20px; }
.project-features li {
  position: relative;
  padding-left: 18px;
  color: var(--muted);
  font-size: 0.88rem;
  line-height: 1.55;
}
.project-features li::before {
  content: "✓";
  position: absolute;
  left: 0;
  color: var(--secondary);
  font-size: 0.8rem;
  font-weight: 700;
}
.project-card .tech-badges { margin-top: auto; margin-bottom: 18px; padding-top: 4px; }
.project-links { display: flex; gap: 12px; }
.project-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--primary);
  border: 1px solid color-mix(in srgb, var(--primary) 30%, transparent);
  padding: 9px 16px;
  border-radius: var(--radius-sm);
  transition: background-color var(--transition-fast);
}
.project-link:hover { background: color-mix(in srgb, var(--primary) 10%, transparent); }

/* ---------- 12. Education ---------- */
.education-list { display: flex; flex-direction: column; gap: 20px; }
.education-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 26px 30px;
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 24px;
  box-shadow: var(--shadow-sm);
  transition: border-color var(--transition-base);
}
.education-card:hover { border-color: color-mix(in srgb, var(--primary) 30%, var(--border)); }
.education-degree { font-size: 1.1rem; margin-bottom: 6px; }
.education-school { color: var(--secondary); font-weight: 600; font-size: 0.92rem; margin-bottom: 10px; }
.education-school a {
  color: inherit;
  border-bottom: 1px solid transparent;
  transition: color var(--transition-fast), border-color var(--transition-fast);
}
.education-school a:hover { color: var(--primary); border-bottom-color: var(--primary); }
.education-detail { color: var(--muted); font-size: 0.9rem; max-width: 640px; }
.education-cert-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  margin-top: 14px;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--primary);
  background: transparent;
  border: 1px solid color-mix(in srgb, var(--primary) 30%, transparent);
  padding: 7px 13px;
  border-radius: var(--radius-sm);
  transition: background-color var(--transition-fast), transform var(--transition-fast);
}
.education-cert-btn:hover { background: color-mix(in srgb, var(--primary) 10%, transparent); transform: translateY(-1px); }
.education-meta { flex-shrink: 0; text-align: right; }
.education-duration {
  display: inline-block;
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--muted);
  background: var(--surface);
  border: 1px solid var(--border);
  padding: 6px 12px;
  border-radius: 999px;
  white-space: nowrap;
}

/* ---------- 13. Certifications ---------- */
.cert-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 24px;
}
.cert-card {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 18px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition-base), box-shadow var(--transition-base), border-color var(--transition-base);
}
.cert-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
  border-color: color-mix(in srgb, var(--primary) 35%, var(--border));
}

.cert-badge-new {
  display: inline-flex;
  align-items: center;
  vertical-align: middle;
  margin-left: 6px;
  font-size: 0.62rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: #fff;
  background: var(--gradient-primary);
  padding: 3px 9px;
  border-radius: 999px;
  box-shadow: var(--shadow-sm);
  transform: translateY(-1px);
}

.cert-header {
  display: flex;
  align-items: flex-start;
  gap: 14px;
}
.cert-monogram {
  flex-shrink: 0;
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
  border-radius: 12px;
}
.cert-monogram--anthropic { background: var(--gradient-primary); color: #fff; }
.cert-monogram--coursera {
  background: var(--surface);
  border: 1px solid var(--border);
  color: #0056D2;
}
.cert-header-text { min-width: 0; }
.cert-title { font-size: 1.02rem; margin-bottom: 5px; line-height: 1.4; }
.cert-issuer { color: var(--secondary); font-weight: 600; font-size: 0.85rem; }

.cert-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  font-size: 0.78rem;
  color: var(--muted);
  padding-top: 16px;
  border-top: 1px solid var(--border);
  margin-top: auto;
}
.cert-id { font-family: 'SFMono-Regular', Consolas, monospace; }

.cert-verify {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--muted);
  transition: color var(--transition-fast);
}
.cert-verify svg { transition: transform var(--transition-fast); }
.cert-card:hover .cert-verify { color: var(--primary); }
.cert-card:hover .cert-verify svg { transform: translate(2px, -2px); }

/* ---------- 14. Contact ---------- */
.contact-grid {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: 40px;
  align-items: start;
}
.contact-list { display: flex; flex-direction: column; gap: 4px; }
.contact-item {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 18px 8px;
  border-bottom: 1px solid var(--border);
}
.contact-item:last-child { border-bottom: none; }
.contact-icon {
  display: grid;
  place-items: center;
  width: 42px;
  height: 42px;
  border-radius: var(--radius-sm);
  background: var(--card);
  border: 1px solid var(--border);
  color: var(--primary);
  flex-shrink: 0;
}
.contact-item > div { flex: 1; min-width: 0; }
.contact-label { display: block; font-size: 0.78rem; color: var(--muted); margin-bottom: 2px; }
.contact-value {
  font-weight: 600;
  font-size: 0.98rem;
  word-break: break-word;
}
a.contact-value:hover { color: var(--primary); }
.copy-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--muted);
  border: 1px solid var(--border);
  padding: 7px 12px;
  border-radius: var(--radius-sm);
  flex-shrink: 0;
  transition: color var(--transition-fast), border-color var(--transition-fast);
}
.copy-btn:hover { color: var(--primary); border-color: var(--primary); }

.contact-cta {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 36px;
  box-shadow: var(--shadow-sm);
}
.contact-cta h3 { font-size: 1.3rem; margin-bottom: 12px; }
.contact-cta p { color: var(--muted); margin-bottom: 24px; font-size: 0.95rem; }

/* ---------- 15. Footer ---------- */
.site-footer {
  border-top: 1px solid var(--border);
  padding-block: 32px;
  background: var(--surface);
}
.footer-grid {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}
.site-footer p { color: var(--muted); font-size: 0.88rem; }
.footer-socials { display: flex; gap: 24px; }
.footer-socials a {
  color: var(--muted);
  font-size: 0.88rem;
  font-weight: 500;
  transition: color var(--transition-fast);
}
.footer-socials a:hover { color: var(--primary); }

/* ---------- 16b. Certificate Lightbox ---------- */
.lightbox {
  position: fixed;
  inset: 0;
  z-index: 1300;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 40px;
  background: rgba(3, 7, 18, 0.86);
  backdrop-filter: blur(6px);
  animation: lightbox-fade 200ms ease;
}
.lightbox[hidden] { display: none; }
@keyframes lightbox-fade {
  from { opacity: 0; }
  to { opacity: 1; }
}
.lightbox-img {
  max-width: min(900px, 100%);
  max-height: 88vh;
  width: auto;
  border-radius: 12px;
  box-shadow: var(--shadow-lg);
  background: #fff;
}
.lightbox-close {
  position: absolute;
  top: 24px;
  right: 24px;
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  color: #fff;
  background: rgba(255, 255, 255, 0.12);
  border: 1px solid rgba(255, 255, 255, 0.2);
  transition: background-color var(--transition-fast);
}
.lightbox-close:hover { background: rgba(255, 255, 255, 0.22); }
@media (prefers-reduced-motion: reduce) {
  .lightbox { animation: none; }
}

/* ---------- 16. Scroll to Top ---------- */
.scroll-top-btn {
  position: fixed;
  bottom: 28px;
  right: 28px;
  width: 46px;
  height: 46px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  background: var(--gradient-primary);
  color: #fff;
  box-shadow: var(--shadow-md);
  opacity: 0;
  visibility: hidden;
  transform: translateY(12px);
  transition: opacity var(--transition-base), transform var(--transition-base), visibility var(--transition-base);
  z-index: 900;
}
.scroll-top-btn.is-visible { opacity: 1; visibility: visible; transform: translateY(0); }
.scroll-top-btn:hover { transform: translateY(-3px); }

/* ---------- 17. Responsive ---------- */
@media (max-width: 1024px) {
  .hero-grid { grid-template-columns: 1fr; }
  .hero-visual { max-width: 260px; margin-inline: auto; }
  .about-grid { grid-template-columns: 1fr; }
  .contact-grid { grid-template-columns: 1fr; }
}

@media (max-width: 860px) {
  .section-padding { padding-block: 80px; }

  .nav-toggle { display: flex; }
  .nav-menu {
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 4px;
    background: var(--bg);
    border-bottom: 1px solid var(--border);
    padding: 16px 24px 24px;
    transform: translateY(-12px);
    opacity: 0;
    visibility: hidden;
    transition: transform var(--transition-base), opacity var(--transition-base), visibility var(--transition-base);
  }
  .nav-menu.is-open { transform: translateY(0); opacity: 1; visibility: visible; }
  .nav-link { padding: 12px 14px; }
  .nav-theme { margin-left: 0; margin-top: 8px; }
  .theme-toggle { width: 100%; border-radius: var(--radius-sm); }

  .hero { padding-top: calc(64px + var(--header-height)); }
  .hero-stats { flex-wrap: wrap; gap: 28px; }
  .education-card { flex-direction: column; }
  .education-meta { text-align: left; }
}

@media (max-width: 560px) {
  .container { padding-inline: 18px; }
  .hero-actions { flex-direction: column; align-items: stretch; }
  .hero-socials { justify-content: flex-start; }
  .contact-item { flex-wrap: wrap; }
  .copy-btn { margin-left: 58px; }
}

/* ---------- 18. Print Styles ---------- */
@media print {
  .site-header, .scroll-progress, .scroll-top-btn, .scroll-cue,
  .hero-visual, .theme-toggle, .nav-toggle, .btn, .copy-btn, .site-footer,
  .education-cert-btn, .lightbox { display: none !important; }
  body { background: #fff; color: #0B1220; }
  .section-padding { padding-block: 24px; }
  .card, .timeline-card, .project-card, .cert-card, .education-card, .skill-group, .competencies, .contact-cta {
    box-shadow: none !important;
    border: 1px solid #ccc !important;
    break-inside: avoid;
  }
  a { color: #0B1220 !important; text-decoration: underline; }
  .fade-in { opacity: 1 !important; transform: none !important; }
}