:root {
  --bg: #0f172a;
  --bg-2: #0b1223;
  --card: rgba(255, 255, 255, 0.04);
  --text: #e6e8ec;
  --muted: #9da8b6;
  --primary: #5ce1e6;
  --primary-strong: #38b6ff;
  --border: rgba(255, 255, 255, 0.08);
  --shadow: 0 10px 40px rgba(0, 0, 0, 0.35);
  --glass: rgba(255, 255, 255, 0.06);
  --chip: rgba(255, 255, 255, 0.08);
  --pill-bg: rgba(92, 225, 230, 0.15);
}

[data-theme="light"] {
  --bg: #f7f9fc;
  --bg-2: #ffffff;
  --card: #ffffff;
  --text: #111827;
  --muted: #4b5563;
  --primary: #1f8ef1;
  --primary-strong: #0f6ad8;
  --border: rgba(0, 0, 0, 0.06);
  --shadow: 0 16px 50px rgba(15, 26, 46, 0.12);
  --glass: rgba(255, 255, 255, 0.9);
  --chip: #eef2f6;
  --pill-bg: rgba(31, 142, 241, 0.12);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Space Grotesk", "Manrope", system-ui, -apple-system, sans-serif;
  background: radial-gradient(110% 90% at 20% 20%, rgba(56, 182, 255, 0.08), transparent),
              radial-gradient(90% 70% at 80% 10%, rgba(92, 225, 230, 0.12), transparent),
              linear-gradient(180deg, var(--bg) 0%, var(--bg-2) 100%);
  color: var(--text);
  min-height: 100vh;
  position: relative;
  transition: background 0.4s ease, color 0.4s ease;
  padding-bottom: 96px;
}

a {
  color: inherit;
  text-decoration: none;
}

.floating-blur {
  position: fixed;
  filter: blur(100px);
  opacity: 0.6;
  z-index: 0;
  pointer-events: none;
}

.blur-1 { width: 320px; height: 320px; background: #38b6ff; top: 4rem; left: 6rem; }
.blur-2 { width: 360px; height: 360px; background: #5ce1e6; bottom: 3rem; right: 6rem; }

.glass-nav {
  position: sticky;
  top: 0;
  z-index: 10;
  backdrop-filter: blur(14px);
  background: rgba(15, 23, 42, 0.65);
  border-bottom: 1px solid var(--border);
  transition: background 0.4s ease, border-color 0.4s ease;
}

[data-theme="light"] .glass-nav {
  background: rgba(255, 255, 255, 0.9);
}

.navbar {
  padding: 1rem 0;
}

.navbar-toggler {
  border-color: var(--text);
  color: var(--text);
}

.navbar-toggler .bi-list {
  color: var(--text);
  font-size: 1.5rem;
}

.glass-nav.scrolled {
  box-shadow: var(--shadow);
}

.navbar-brand {
  color: var(--text);
  letter-spacing: 0.5px;
}

.navbar-brand:hover, .navbar-brand:focus {
  color: var(--primary);
}

.nav-link {
  color: var(--muted);
  font-weight: 500;
  margin-left: 1rem;
}

.nav-link:hover, .nav-link:focus {
  color: var(--text);
}

.section {
  position: relative;
  padding: 6rem 0;
  z-index: 1;
}

.hero {
  padding-top: 7rem;
  padding-bottom: 5rem;
}

.eyebrow {
  color: var(--primary);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 1px;
  font-size: 0.9rem;
  margin-bottom: 1rem;
}

.lead {
  max-width: 720px;
}

.btn-primary {
  background: linear-gradient(90deg, var(--primary) 0%, var(--primary-strong) 100%);
  border: none;
  color: #0f172a;
  font-weight: 700;
  box-shadow: 0 10px 40px rgba(56, 182, 255, 0.3);
}

.btn-outline-light {
  color: var(--text);
  border-color: var(--text);
}

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

.stats {
  gap: 1rem;
}

.stat-card {
  background: var(--card);
  border: 1px solid var(--border);
  padding: 1.1rem 1.25rem;
  border-radius: 16px;
  min-width: 170px;
  max-width: 100%;
  box-shadow: var(--shadow);
  transition: background 0.4s ease, border-color 0.4s ease, color 0.4s ease, box-shadow 0.4s ease;
}

.stat-card .label {
  color: var(--muted);
  font-size: 0.9rem;
}

.hero-card {
  position: relative;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 18px;
  padding: 2rem;
  box-shadow: var(--shadow);
  overflow: hidden;
  transition: background 0.4s ease, border-color 0.4s ease, box-shadow 0.4s ease;
}

.hero-card .glow {
  position: absolute;
  width: 320px;
  height: 320px;
  background: radial-gradient(circle, rgba(92, 225, 230, 0.15), transparent);
  top: -60px;
  right: -40px;
  z-index: 0;
}

.hero-card * { position: relative; z-index: 1; }

.hero-card .tag {
  display: inline-flex;
  padding: 0.35rem 0.75rem;
  background: var(--pill-bg);
  color: var(--text);
  border-radius: 999px;
  font-weight: 600;
  font-size: 0.9rem;
  margin-bottom: 1rem;
}

.section-title .pill,
.pill {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.4rem 0.85rem;
  background: var(--pill-bg);
  color: var(--text);
  border-radius: 999px;
  font-weight: 600;
  letter-spacing: 0.5px;
  font-size: 0.95rem;
}

.section-title h2 {
  margin-top: 1rem;
  margin-bottom: 1rem;
}

.highlight-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(210px, 1fr));
  gap: 1rem;
  margin-top: 1.25rem;
}

.highlight-grid div {
  background: var(--card);
  border: 1px solid var(--border);
  padding: 1rem;
  border-radius: 14px;
  transition: background 0.4s ease, border-color 0.4s ease, color 0.4s ease;
}

.video-card {
  background: linear-gradient(135deg, rgba(56, 182, 255, 0.12), rgba(92, 225, 230, 0.16));
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 2rem;
  box-shadow: var(--shadow);
}

.video-card .badge {
  background: #0b1223;
  color: var(--text);
  border: 1px solid var(--border);
  padding: 0.4rem 0.7rem;
  border-radius: 999px;
  font-weight: 600;
  display: inline-block;
  margin-bottom: 1rem;
}

.chips {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  margin-top: 1rem;
}

.chips span {
  padding: 0.45rem 0.8rem;
  background: var(--chip);
  border: 1px solid var(--border);
  border-radius: 999px;
  font-weight: 600;
  color: var(--text);
}

.project-card {
  position: relative;
  overflow: hidden;
  border-radius: 18px;
  background: var(--card);
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
  transition: transform 0.4s ease, box-shadow 0.4s ease;
}

.project-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.35);
}

.project-cover {
  height: 180px;
  background-size: cover;
  background-position: center;
  border-bottom: 1px solid var(--border);
}

.cover-techinvest { background-image: linear-gradient(120deg, #38b6ff, #5ce1e6); }
.cover-recsys { background-image: linear-gradient(120deg, #111827, #38b6ff); }
.cover-booksmart { background-image: linear-gradient(120deg, #5ce1e6, #0ea5e9); }
.cover-easylang { background-image: linear-gradient(120deg, #1d2433, #8b5cf6); }
.cover-finance { background-image: linear-gradient(120deg, #0b1223, #38b6ff); }

.project-body {
  padding: 1.4rem;
}

.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.tags span {
  background: var(--chip);
  border-radius: 999px;
  padding: 0.35rem 0.75rem;
  font-weight: 600;
  border: 1px solid var(--border);
  transition: background 0.4s ease, border-color 0.4s ease, color 0.4s ease;
}

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

.timeline::before {
  content: "";
  position: absolute;
  left: 16px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: linear-gradient(180deg, var(--primary), transparent);
}

.timeline-item {
  position: relative;
  padding-left: 2.5rem;
  margin-bottom: 2rem;
}

.timeline-dot {
  position: absolute;
  left: 7px;
  top: 14px;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--primary);
  box-shadow: 0 0 20px rgba(56, 182, 255, 0.5);
}

.stack-card, .lang-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 1.3rem;
  box-shadow: var(--shadow);
  height: 100%;
  transition: background 0.4s ease, border-color 0.4s ease, box-shadow 0.4s ease, color 0.4s ease;
}

.skill-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  gap: 0.75rem;
  margin-top: 2rem;
}

.chip {
  background: var(--chip);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 0.6rem 0.75rem;
  text-align: center;
  font-weight: 600;
  transition: background 0.4s ease, border-color 0.4s ease, color 0.4s ease;
}

.lang-card .progress {
  height: 10px;
  margin-top: 0.85rem;
  background: var(--border);
}

.lang-card .progress-bar {
  background: linear-gradient(90deg, var(--primary) 0%, var(--primary-strong) 100%);
}

.cta-card {
  background: linear-gradient(120deg, rgba(56, 182, 255, 0.18), rgba(92, 225, 230, 0.2));
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 2.2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
  box-shadow: var(--shadow);
  flex-wrap: wrap;
  transition: background 0.4s ease, border-color 0.4s ease, box-shadow 0.4s ease, color 0.4s ease;
}

.footer {
  border-top: 1px solid var(--border);
  padding: 1.1rem 0;
  background: rgba(15, 23, 42, 0.9);
  position: fixed;
  left: 0;
  bottom: 0;
  width: 100%;
  z-index: 12;
  backdrop-filter: blur(10px);
  transition: background 0.4s ease, border-color 0.4s ease;
}

[data-theme="light"] .footer {
  background: rgba(255, 255, 255, 0.9);
}

.text-secondary {
  color: var(--muted) !important;
}

.scroll-top {
  position: fixed;
  right: 24px;
  bottom: 96px;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  display: grid;
  place-items: center;
  background: var(--card);
  border: 1px solid var(--border);
  color: var(--text);
  box-shadow: var(--shadow);
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s ease, transform 0.3s ease;
  z-index: 9;
}

.scroll-top.show {
  opacity: 1;
  visibility: visible;
  transform: translateY(-4px);
}

.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

@media (max-width: 992px) {
  .hero {
    padding-top: 6rem;
  }

  .cta-card {
    flex-direction: column;
    align-items: flex-start;
  }
}

@media (max-width: 576px) {
  .navbar-brand { font-size: 1rem; }
  .display-4 { font-size: 2.2rem; }
  .stat-card { width: 100%; }
  .scroll-top { right: 16px; bottom: 96px; }
}