:root {
  --bg: #080b12;
  --surface: #111827;
  --surface-2: #172033;
  --text: #f7fafc;
  --muted: #a7b0c3;
  --accent: #7c3aed;
  --accent-2: #22d3ee;
  --border: rgba(255,255,255,0.12);
  --shadow: 0 24px 80px rgba(0, 0, 0, 0.38);
}

body.light {
  --bg: #f6f7fb;
  --surface: #ffffff;
  --surface-2: #eef2ff;
  --text: #111827;
  --muted: #536074;
  --accent: #5b21b6;
  --accent-2: #047d95;
  --border: rgba(17,24,39,0.13);
  --shadow: 0 22px 60px rgba(17, 24, 39, 0.12);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: radial-gradient(circle at top left, rgba(124, 58, 237, 0.25), transparent 32%),
              radial-gradient(circle at top right, rgba(34, 211, 238, 0.15), transparent 28%),
              var(--bg);
  color: var(--text);
  min-height: 100vh;
}

a { color: inherit; }
.page-shell { width: min(1180px, calc(100% - 32px)); margin: 0 auto; }
.site-header { position: sticky; top: 0; z-index: 10; padding: 18px 0; backdrop-filter: blur(18px); }
.navbar {
  display: flex; align-items: center; justify-content: space-between; gap: 18px;
  background: color-mix(in srgb, var(--surface) 88%, transparent);
  border: 1px solid var(--border); border-radius: 22px; padding: 12px 14px; box-shadow: var(--shadow);
}
.brand { display: flex; align-items: center; gap: 10px; text-decoration: none; font-weight: 800; }
.brand-mark { display: grid; place-items: center; width: 42px; height: 42px; border-radius: 14px; background: linear-gradient(135deg, var(--accent), var(--accent-2)); color: white; }
.nav-actions { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; justify-content: flex-end; }
.nav-link, .theme-toggle, .menu-toggle {
  border: 1px solid transparent; background: transparent; color: var(--muted); border-radius: 999px; padding: 10px 14px; cursor: pointer; font-weight: 700;
}
.nav-link:hover, .nav-link.active, .theme-toggle:hover { color: var(--text); border-color: var(--border); background: var(--surface-2); }
.theme-toggle { display: flex; align-items: center; gap: 8px; }
.menu-toggle { display: none; font-size: 22px; }
main { padding: 54px 0 34px; }
.tab-section { display: none; animation: fadeIn 0.36s ease; }
.tab-section.active { display: block; }
.hero-grid { display: grid; grid-template-columns: minmax(0, 1.6fr) minmax(280px, 0.8fr); gap: 28px; align-items: stretch; }
.hero-copy, .profile-card, .panel, .timeline-card, .project-card, .awards-panel, .stat-card {
  background: linear-gradient(180deg, color-mix(in srgb, var(--surface) 96%, transparent), color-mix(in srgb, var(--surface-2) 84%, transparent));
  border: 1px solid var(--border); border-radius: 28px; box-shadow: var(--shadow);
}
.hero-copy { padding: clamp(28px, 6vw, 68px); }
.eyebrow { color: var(--accent-2); text-transform: uppercase; letter-spacing: 0.16em; font-size: 0.78rem; font-weight: 900; }
h1 { font-size: clamp(2.35rem, 6vw, 5rem); line-height: 0.95; margin: 12px 0 22px; letter-spacing: -0.06em; }
h2 { font-size: clamp(2rem, 4vw, 3.2rem); margin: 0; letter-spacing: -0.04em; }
h3 { margin: 8px 0; font-size: 1.2rem; }
h4 { margin: 22px 0 8px; }
p, li { color: var(--muted); line-height: 1.7; }
.hero-summary { max-width: 780px; font-size: 1.1rem; }
.hero-buttons { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 28px; }
.button { text-decoration: none; border-radius: 999px; padding: 13px 18px; font-weight: 900; border: 1px solid var(--border); transition: transform 0.2s ease, border-color 0.2s ease; }
.button:hover { transform: translateY(-2px); }
.button.primary { background: linear-gradient(135deg, var(--accent), var(--accent-2)); color: white; border: 0; }
.button.secondary { background: var(--surface-2); }
.profile-card { padding: 22px; }
.photo-placeholder { min-height: 330px; display: grid; place-items: center; text-align: center; border: 1px dashed var(--border); border-radius: 22px; background: linear-gradient(135deg, rgba(124,58,237,0.15), rgba(34,211,238,0.10)); overflow: hidden; }
.photo-placeholder span { display: block; font-weight: 900; font-size: 1.3rem; }
.photo-placeholder small { display: block; color: var(--muted); margin-top: 8px; }
.profile-card.has-photo .photo-placeholder { background-image: url('assets/profile.jpg'); background-size: cover; background-position: center; }
.profile-card.has-photo .photo-placeholder span, .profile-card.has-photo .photo-placeholder small { display: none; }
.profile-details a { color: var(--accent-2); text-decoration: none; }
.stats-grid, .cards-grid, .education-grid, .skills-layout { display: grid; gap: 18px; margin-top: 26px; }
.stats-grid { grid-template-columns: repeat(4, minmax(0, 1fr)); }
.stat-card { padding: 22px; }
.stat-card span { display: block; font-size: 2rem; font-weight: 950; color: var(--accent-2); }
.section-heading { margin-bottom: 24px; }
.timeline { display: grid; gap: 18px; }
.timeline-card { padding: 24px; display: grid; grid-template-columns: minmax(220px, 0.6fr) 1fr; gap: 20px; }
.date-chip { display: inline-flex; width: fit-content; border: 1px solid var(--border); border-radius: 999px; padding: 7px 11px; color: var(--accent-2); font-size: 0.82rem; font-weight: 900; }
.cards-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.project-card, .panel, .awards-panel { padding: 24px; }
.accordion { border: 1px solid var(--border); border-radius: 26px; overflow: hidden; background: var(--surface); box-shadow: var(--shadow); }
.accordion-header { width: 100%; display: flex; justify-content: space-between; align-items: center; background: transparent; color: var(--text); padding: 20px 24px; border: 0; border-bottom: 1px solid var(--border); font-size: 1rem; font-weight: 900; cursor: pointer; text-align: left; }
.accordion-content { max-height: 0; overflow: hidden; transition: max-height 0.25s ease; border-bottom: 1px solid var(--border); }
.accordion-content p { margin: 0; padding: 0 24px 20px; }
.accordion-header.open + .accordion-content { max-height: 220px; }
.education-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.award-list { columns: 2; padding-left: 20px; }
.skills-layout { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.tag-cloud { display: flex; flex-wrap: wrap; gap: 10px; }
.tag-cloud > span, .tag-cloud > a { background: var(--surface-2); color: var(--text); border: 1px solid var(--border); padding: 9px 12px; border-radius: 999px; font-weight: 800; }
.tag-cloud > a { text-decoration: none; transition: transform 0.2s ease, border-color 0.2s ease, color 0.2s ease; }
.tag-cloud > a:hover, .tag-cloud > a:focus-visible { color: var(--accent-2); border-color: var(--accent-2); transform: translateY(-2px); }
.certification-links > a { display: inline-flex; align-items: center; gap: 7px; }
.certification-links > a span { font-size: 0.85em; }
.site-footer { padding: 26px 0 46px; text-align: center; }
.reveal { opacity: 0; transform: translateY(14px); transition: opacity 0.5s ease, transform 0.5s ease; }
.reveal.visible { opacity: 1; transform: translateY(0); }
@keyframes fadeIn { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: translateY(0); } }
@media (max-width: 860px) {
  .menu-toggle { display: block; }
  .nav-actions { display: none; width: 100%; justify-content: flex-start; }
  .nav-actions.open { display: flex; }
  .navbar { flex-wrap: wrap; }
  .hero-grid, .timeline-card, .education-grid, .skills-layout, .cards-grid, .stats-grid { grid-template-columns: 1fr; }
  .hero-copy { padding: 30px; }
  .award-list { columns: 1; }
}