/* ==========================================================================
   Reset & base
   ========================================================================== */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body, h1, h2, h3, h4, p, ul { margin: 0; padding: 0; }
ul { list-style: none; }
a { text-decoration: none; color: inherit; }
img { max-width: 100%; display: block; }
button { font: inherit; cursor: pointer; }

/* ==========================================================================
   Theme tokens — professional site
   ========================================================================== */
:root {
  --font-heading: 'Space Grotesk', sans-serif;
  --font-body: 'Inter', sans-serif;

  --bg: #0b0f19;
  --bg-alt: #10151f;
  --surface: #151b28;
  --border: #232b3d;

  --text: #e9edf5;
  --text-muted: #9aa4b8;

  --accent: #5b8cff;
  --accent-soft: rgba(91, 140, 255, 0.12);
  --accent-contrast: #0b0f19;

  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 20px;

  --shadow: 0 10px 30px rgba(0, 0, 0, 0.35);
  --transition: 400ms cubic-bezier(0.65, 0, 0.35, 1);
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

.container {
  width: 100%;
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ==========================================================================
   Header
   ========================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: color-mix(in srgb, var(--bg) 85%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
  transition: background var(--transition), border-color var(--transition);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
  gap: 24px;
}

.logo {
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 1.35rem;
  letter-spacing: -0.02em;
}

.logo-dot { color: var(--accent); }

.nav {
  display: flex;
  gap: 28px;
  font-weight: 500;
  font-size: 0.95rem;
}

.nav a {
  color: var(--text-muted);
  position: relative;
  padding: 6px 0;
  transition: color var(--transition);
}

.nav a:hover { color: var(--text); }

.nav a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 0;
  height: 2px;
  background: var(--accent);
  transition: width 250ms ease;
}

.nav a:hover::after { width: 100%; }

/* ---- Site switch (links out to the casual site) --------------------- */
.site-switch {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}

.site-switch-label {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--accent);
  white-space: nowrap;
}

.site-switch-label--muted { color: var(--text-muted); }

.site-switch-visual {
  position: relative;
  width: 52px;
  height: 28px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--surface);
  padding: 3px;
  transition: background 200ms ease, border-color 200ms ease;
}

.site-switch:hover .site-switch-visual { border-color: var(--accent); }

.site-switch-thumb {
  display: block;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--accent);
  transition: transform 200ms ease;
}

.site-switch:hover .site-switch-thumb { transform: translateX(4px); }

/* ---- Top-of-page hint (nudges toward the casual site switch) -------- */
.top-hint {
  position: fixed;
  top: 84px;
  left: 65%;
  z-index: 101;
  display: flex;
  align-items: flex-end;
  gap: 8px;
  transform: translate(-42%, -10px);
  color: var(--accent);
  opacity: 0;
  pointer-events: none;
  transition: opacity 300ms ease, transform 300ms ease;
}

.top-hint.is-visible {
  opacity: 1;
  transform: translate(-42%, 0);
  pointer-events: auto;
}

.top-hint-text {
  font-family: var(--font-heading);
  font-style: italic;
  font-weight: 500;
  font-size: 0.85rem;
  line-height: 1.3;
  max-width: 190px;
  color: var(--accent);
  transform: rotate(-2deg);
  transition: color 200ms ease;
}

.top-hint-arrow {
  width: 84px;
  height: 60px;
  flex-shrink: 0;
  color: var(--accent);
  transition: color 200ms ease;
}

.top-hint:hover .top-hint-text,
.top-hint:hover .top-hint-arrow { color: var(--text); }

@media (max-width: 900px) {
  .top-hint { display: none; }
}

/* ==========================================================================
   Hero / About Me
   ========================================================================== */
.hero {
  padding: 120px 0 100px;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: "";
  position: absolute;
  inset: -20% -10% auto -10%;
  height: 420px;
  background: radial-gradient(60% 60% at 50% 0%, var(--accent-soft), transparent 70%);
  pointer-events: none;
  transition: background var(--transition);
}

.hero-inner {
  position: relative;
  max-width: 780px;
}

.eyebrow {
  display: inline-block;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--accent);
  background: var(--accent-soft);
  padding: 6px 14px;
  border-radius: 999px;
  margin-bottom: 24px;
}

.hero-title {
  font-family: var(--font-heading);
  font-size: clamp(2.2rem, 5vw, 3.4rem);
  font-weight: 700;
  line-height: 1.1;
  margin-bottom: 20px;
  letter-spacing: -0.02em;
}

.hero-subtitle {
  font-size: 1.1rem;
  color: var(--text-muted);
  max-width: 620px;
  margin-bottom: 36px;
}

.hero-actions {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 13px 26px;
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: 0.95rem;
  transition: transform var(--transition), background var(--transition), color var(--transition), border-color var(--transition);
  border: 1px solid transparent;
}

.btn:hover { transform: translateY(-2px); }

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

.btn-secondary {
  background: transparent;
  border-color: var(--border);
  color: var(--text);
}

/* ==========================================================================
   Section shared
   ========================================================================== */
.section { padding: 90px 0; }

.section-alt {
  background: var(--bg-alt);
  transition: background var(--transition);
}

.section-title {
  font-family: var(--font-heading);
  font-size: clamp(1.6rem, 3vw, 2.2rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 48px;
}

/* ==========================================================================
   Education & Skills
   ========================================================================== */
.edu-skills-grid {
  display: grid;
  grid-template-columns: 1.1fr 1fr;
  gap: 32px;
}

.edu-card, .skills-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 36px;
  transition: background var(--transition), border-color var(--transition);
}

.edu-card h3, .skills-card h3 {
  font-family: var(--font-heading);
  font-size: 1.2rem;
  margin-bottom: 24px;
}

.edu-item { margin-bottom: 28px; }
.edu-item:last-child { margin-bottom: 0; }

.edu-item-header {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 12px;
  flex-wrap: wrap;
}

.edu-item-header h4 {
  font-size: 1.02rem;
  font-weight: 600;
}

.edu-date {
  font-size: 0.82rem;
  color: var(--accent);
  font-weight: 600;
  white-space: nowrap;
}

.edu-school {
  color: var(--text-muted);
  font-size: 0.92rem;
  margin-top: 4px;
}

.edu-desc {
  font-size: 0.92rem;
  color: var(--text-muted);
  margin-top: 8px;
}

.skills-group { margin-bottom: 22px; }
.skills-group:last-child { margin-bottom: 0; }

.skills-group-title {
  font-size: 0.82rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-muted);
  margin-bottom: 12px;
}

.tag-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.tag {
  font-size: 0.85rem;
  font-weight: 500;
  padding: 7px 14px;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent);
  transition: background var(--transition), color var(--transition);
}

/* ==========================================================================
   Certifications carousel
   ========================================================================== */
.cert-block { margin-top: 32px; }

.cert-heading {
  font-family: var(--font-heading);
  font-size: 1.2rem;
  margin-bottom: 20px;
}

.cert-carousel {
  display: flex;
  align-items: center;
  gap: 16px;
}

.cert-viewport {
  flex: 1;
  overflow: hidden;
}

.cert-track {
  display: flex;
  transition: transform 450ms cubic-bezier(0.65, 0, 0.35, 1);
}

.cert-slide {
  flex: 0 0 100%;
  min-width: 0;
  padding: 4px;
}

.cert-card {
  display: flex;
  align-items: center;
  gap: 24px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 32px 36px;
}

.cert-badge {
  flex-shrink: 0;
  width: 76px;
  height: 76px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--accent-contrast);
  background: linear-gradient(135deg, var(--accent), color-mix(in srgb, var(--accent) 60%, white));
}

.cert-info h4 {
  font-size: 1.05rem;
  font-weight: 600;
  margin-bottom: 4px;
}

.cert-issuer {
  color: var(--accent);
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 6px;
}

.cert-meta {
  color: var(--text-muted);
  font-size: 0.85rem;
}

.cert-nav {
  flex-shrink: 0;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: border-color 200ms ease, color 200ms ease, transform 200ms ease;
}

.cert-nav:hover {
  border-color: var(--accent);
  color: var(--accent);
  transform: translateY(-1px);
}

.cert-dots {
  display: flex;
  justify-content: center;
  gap: 8px;
  margin-top: 20px;
}

.cert-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--border);
  border: none;
  padding: 0;
  transition: background 200ms ease, transform 200ms ease;
}

.cert-dot[aria-current="true"] {
  background: var(--accent);
  transform: scale(1.3);
}

/* ==========================================================================
   Work Experience — timeline
   ========================================================================== */
.timeline {
  position: relative;
  padding-left: 32px;
  border-left: 2px solid var(--border);
  transition: border-color var(--transition);
}

.timeline-item {
  position: relative;
  padding-bottom: 48px;
}

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

.timeline-dot {
  position: absolute;
  left: -39px;
  top: 4px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--bg-alt);
  border: 3px solid var(--accent);
  transition: background var(--transition), border-color var(--transition);
}

.timeline-header {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 12px;
  flex-wrap: wrap;
}

.timeline-header h3 {
  font-family: var(--font-heading);
  font-size: 1.15rem;
  font-weight: 600;
}

.timeline-date {
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--accent);
  white-space: nowrap;
}

.timeline-company {
  color: var(--text-muted);
  font-weight: 500;
  font-size: 0.95rem;
  margin-top: 4px;
  margin-bottom: 14px;
}

.timeline-list li {
  position: relative;
  padding-left: 20px;
  font-size: 0.95rem;
  color: var(--text-muted);
  margin-bottom: 10px;
}

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

.timeline-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 9px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent);
}

/* ==========================================================================
   Footer
   ========================================================================== */
.site-footer {
  background: var(--surface);
  border-top: 1px solid var(--border);
  transition: background var(--transition), border-color var(--transition);
}

.footer-inner {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr;
  gap: 40px;
  padding: 64px 24px 48px;
}

.footer-col h3 {
  font-family: var(--font-heading);
  font-size: 1.3rem;
  margin-bottom: 14px;
}

.footer-col h4 {
  font-size: 0.95rem;
  font-weight: 700;
  margin-bottom: 18px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-muted);
}

.footer-col p {
  color: var(--text-muted);
  font-size: 0.95rem;
  max-width: 340px;
}

.footer-links li { margin-bottom: 12px; }
.footer-links li:last-child { margin-bottom: 0; }

.footer-links a {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--text-muted);
  font-size: 0.92rem;
  transition: color var(--transition);
}

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

.footer-links .icon { font-size: 0.95rem; }
.footer-links li > .icon { margin-right: 8px; }

.footer-bottom {
  border-top: 1px solid var(--border);
  padding: 22px 0;
  transition: border-color var(--transition);
}

.footer-bottom p {
  font-size: 0.82rem;
  color: var(--text-muted);
  text-align: center;
}

/* ==========================================================================
   Responsive
   ========================================================================== */
@media (max-width: 860px) {
  .edu-skills-grid { grid-template-columns: 1fr; }
  .footer-inner { grid-template-columns: 1fr; gap: 32px; }
}

@media (max-width: 720px) {
  .nav { display: none; }
  .header-inner { justify-content: space-between; }
  .hero { padding: 90px 0 70px; }
  .section { padding: 64px 0; }
}

@media (max-width: 560px) {
  .cert-card { flex-direction: column; text-align: center; padding: 28px 20px; }
}

@media (max-width: 480px) {
  .site-switch-label { display: none; }
}