/* ============================================================
   Tung Anh Le — "Nebula" coding landing page
   ============================================================ */
:root {
  --bg-page: #0a0c14;
  --card: #070b18;
  --ink: #e7ecf7;
  --muted: #a4b0cf;
  --muted-2: #9aa8c9;
  --muted-3: #8ea0c7;
  --blue: #6a9bff;
  --teal: #43d9d0;
  --ink-dark: #04101a;
  --line: rgba(255, 255, 255, 0.09);
  --line-soft: rgba(255, 255, 255, 0.08);
  --glass: rgba(255, 255, 255, 0.045);
  --grad: linear-gradient(90deg, var(--blue), var(--teal));
  --radius-lg: 22px;
  --radius-md: 18px;
  --radius-sm: 16px;
  --shell-w: 1180px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg-page);
  color: var(--ink);
  font-family: "Manrope", system-ui, -apple-system, sans-serif;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; text-decoration: none; }
a:hover { opacity: 0.85; }
img { display: block; }
h1, h2, h3 { margin: 0; }

.gradient-text {
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.eyebrow {
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 1px;
  color: var(--teal);
  text-transform: uppercase;
}

/* ---------- buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  border-radius: 100px;
  transition: transform 0.18s ease, opacity 0.18s ease;
  white-space: nowrap;
}
.btn:hover { transform: translateY(-2px); opacity: 1; }
.btn-primary {
  background: var(--grad);
  color: var(--ink-dark);
}
.btn-ghost {
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.12);
  color: var(--ink);
  font-weight: 600;
}

/* ---------- shell ---------- */
.page {
  display: flex;
  justify-content: center;
  padding: 60px 40px;
}
.shell {
  width: 100%;
  max-width: var(--shell-w);
  position: relative;
  background: var(--card);
  border-radius: var(--radius-lg);
  overflow: hidden;
}
.blob {
  position: absolute;
  border-radius: 50%;
  pointer-events: none;
  filter: blur(44px);
  z-index: 0;
}
.blob-1 {
  top: -120px; left: -80px; width: 520px; height: 520px;
  background: radial-gradient(circle, rgba(106, 155, 255, 0.35), transparent 65%);
}
.blob-2 {
  top: 280px; right: -120px; width: 480px; height: 480px;
  background: radial-gradient(circle, rgba(67, 217, 208, 0.22), transparent 65%);
  filter: blur(50px);
}
.shell > *:not(.blob) { position: relative; z-index: 1; }

/* ---------- nav ---------- */
.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 26px 44px;
}
.brand { display: flex; align-items: center; gap: 12px; }
.brand-mark {
  width: 34px; height: 34px; border-radius: 50%;
  background: linear-gradient(135deg, var(--blue), var(--teal));
  color: var(--ink-dark);
  display: flex; align-items: center; justify-content: center;
  font-weight: 800; font-size: 18px;
}
.brand-name { font-weight: 700; font-size: 17px; }
.nav-links {
  display: flex; align-items: center; gap: 30px;
  font-size: 15px; color: var(--muted-2);
}
.nav-links a:not(.btn):hover { color: var(--ink); opacity: 1; }
.nav .btn { padding: 9px 18px; font-size: 15px; }
.nav-toggle { display: none; }

/* ---------- hero ---------- */
.hero { text-align: center; padding: 70px 40px 54px; }
.pill {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 14px; color: var(--muted-2);
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--line);
  padding: 7px 16px; border-radius: 100px; margin-bottom: 30px;
}
.hero h1 {
  font-size: 78px; line-height: 1.03;
  margin: 0 auto 24px; max-width: 900px;
  font-weight: 800; letter-spacing: -2.5px;
}
.hero p {
  font-size: 20px; line-height: 1.6; color: var(--muted);
  max-width: 640px; margin: 0 auto 36px;
}
.hero strong { color: var(--ink); }
.hero-cta {
  display: flex; gap: 14px; justify-content: center;
  margin-bottom: 56px; flex-wrap: wrap;
}
.hero-cta .btn { font-size: 16px; padding: 16px 30px; }
.avatar-wrap { position: relative; width: 220px; height: 220px; margin: 0 auto; }
.avatar-glow {
  position: absolute; inset: -16px; border-radius: 50%;
  background: linear-gradient(135deg, var(--blue), var(--teal));
  filter: blur(24px); opacity: 0.5;
}
.avatar {
  position: relative; width: 100%; height: 100%;
  object-fit: cover; border-radius: 50%;
  border: 3px solid rgba(255, 255, 255, 0.12);
}
.avatar-tag {
  position: absolute; bottom: -6px; left: 50%;
  transform: translateX(-50%);
  background: #0b1224; border: 1px solid rgba(255, 255, 255, 0.12);
  padding: 6px 16px; border-radius: 100px;
  font-size: 13px; font-weight: 600; white-space: nowrap;
}

/* ---------- stats ---------- */
.stats {
  display: grid; grid-template-columns: repeat(4, 1fr);
  gap: 16px; padding: 0 44px 20px;
}
.stat {
  background: var(--glass); border: 1px solid var(--line);
  border-radius: var(--radius-md); padding: 26px;
  text-align: center; backdrop-filter: blur(10px);
}
.stat-num { font-size: 40px; font-weight: 800; line-height: 1; }
.stat-label { font-size: 14px; color: var(--muted-2); margin-top: 8px; }

/* ---------- marquee ---------- */
.marquee { overflow: hidden; padding: 20px 0; margin: 24px 0; }
.marquee-track {
  display: flex; gap: 44px; width: max-content;
  animation: marquee 30s linear infinite;
  font-size: 15px; color: var(--muted-3); white-space: nowrap;
}
@keyframes marquee { from { transform: translateX(0); } to { transform: translateX(-50%); } }
@media (prefers-reduced-motion: reduce) {
  .marquee-track { animation: none; }
}

/* ---------- section heads ---------- */
.section { padding: 36px 44px 60px; }
.section-head { text-align: center; margin-bottom: 38px; }
.section-head h2 {
  font-size: 44px; font-weight: 800;
  margin: 10px 0 8px; letter-spacing: -1px;
}
.section-head p { color: var(--muted); max-width: 560px; margin: 0 auto; }

/* ---------- videos ---------- */
.video-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.video-card {
  display: block; background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--line-soft); border-radius: var(--radius-sm);
  overflow: hidden; transition: transform 0.2s ease, border-color 0.2s ease;
}
.video-card:hover { transform: translateY(-4px); border-color: rgba(106, 155, 255, 0.4); opacity: 1; }
.video-thumb { position: relative; }
.video-thumb img { width: 100%; aspect-ratio: 16 / 9; object-fit: cover; }
.video-tag {
  position: absolute; top: 12px; left: 12px;
  background: var(--grad); color: var(--ink-dark);
  font-size: 12px; font-weight: 700; padding: 4px 10px; border-radius: 100px;
}
.video-body { padding: 16px 18px 20px; }
.video-meta { font-size: 13px; color: var(--muted-3); margin-bottom: 8px; }
.video-title { font-size: 16px; font-weight: 700; line-height: 1.35; }
.section-more { text-align: center; margin-top: 34px; }
.section-more .btn { padding: 13px 26px; }

/* ---------- about ---------- */
.about {
  display: grid; grid-template-columns: 0.9fr 1.1fr;
  gap: 44px; padding: 20px 44px 60px; align-items: center;
}
.about-photo { position: relative; }
.about-photo-glow {
  position: absolute; inset: -12px;
  background: linear-gradient(135deg, rgba(106, 155, 255, 0.3), rgba(67, 217, 208, 0.2));
  filter: blur(30px); border-radius: 24px;
}
.about-photo img {
  position: relative; width: 100%; border-radius: 20px;
  border: 1px solid rgba(255, 255, 255, 0.12);
  aspect-ratio: 1 / 1; object-fit: cover;
}
.about h2 { font-size: 40px; font-weight: 800; margin: 10px 0 20px; letter-spacing: -1px; }
.about p { color: var(--muted); line-height: 1.7; margin: 0 0 16px; font-size: 17px; }
.about strong { color: var(--ink); }
.chips { display: flex; flex-wrap: wrap; gap: 10px; margin: 24px 0 26px; }
.chip {
  background: rgba(255, 255, 255, 0.05); border: 1px solid rgba(255, 255, 255, 0.1);
  padding: 8px 14px; border-radius: 100px; font-size: 14px;
}
.link-teal { color: var(--teal); font-weight: 700; }

/* ---------- growth ---------- */
.growth-card {
  background: rgba(255, 255, 255, 0.04); border: 1px solid var(--line-soft);
  border-radius: 20px; padding: 38px;
}
.growth-head {
  display: flex; justify-content: space-between; align-items: flex-end;
  margin-bottom: 22px; gap: 20px;
}
.growth-head h2 { font-size: 34px; font-weight: 800; margin: 8px 0 0; letter-spacing: -0.8px; }
.growth-note { font-size: 15px; color: var(--muted); text-align: right; }
.growth-card svg { width: 100%; height: 200px; }
.growth-axis {
  display: flex; justify-content: space-between;
  font-size: 13px; color: var(--muted-3); margin-top: 6px;
}

/* ---------- tools ---------- */
.tools { text-align: center; }
.tools h2 { font-size: 38px; font-weight: 800; margin: 10px 0 28px; letter-spacing: -0.9px; }
.tool-row { display: flex; flex-wrap: wrap; gap: 14px; justify-content: center; }
.tool {
  display: flex; align-items: center; gap: 12px;
  background: var(--glass); border: 1px solid var(--line);
  border-radius: 100px; padding: 12px 22px 12px 12px;
}
.tool-mark {
  width: 36px; height: 36px; border-radius: 50%;
  background: linear-gradient(135deg, var(--blue), var(--teal));
  color: var(--ink-dark); display: flex; align-items: center; justify-content: center;
  font-weight: 800;
}
.tool span { font-weight: 600; font-size: 16px; }
.topics-label {
  margin-top: 44px; font-size: 14px; font-weight: 700; letter-spacing: 1px;
  color: var(--muted-3); text-transform: uppercase;
}
.topics { display: flex; gap: 40px; justify-content: center; margin-top: 18px; flex-wrap: wrap; }
.topics span { font-size: 24px; font-weight: 700; color: #c7d0e8; }

/* ---------- off camera ---------- */
.offcam-inner {
  position: relative; border-radius: var(--radius-lg);
  overflow: hidden; min-height: 340px;
}
.offcam-inner img { width: 100%; height: 340px; object-fit: cover; }
.offcam-veil {
  position: absolute; inset: 0;
  background: linear-gradient(90deg, rgba(7, 11, 24, 0.95) 30%, transparent);
}
.offcam-copy {
  position: absolute; top: 50%; left: 44px;
  transform: translateY(-50%); max-width: 480px;
}
.offcam-copy h2 { font-size: 34px; font-weight: 800; margin: 10px 0 14px; letter-spacing: -0.8px; }
.offcam-copy p { color: #c7d0e8; line-height: 1.7; margin: 0; font-size: 17px; }
.offcam-copy strong { color: #fff; }

/* ---------- contact ---------- */
.contact { text-align: center; }
.contact-card {
  background: linear-gradient(135deg, rgba(106, 155, 255, 0.18), rgba(67, 217, 208, 0.12));
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 24px; padding: 56px 40px;
}
.contact-card h2 { font-size: 48px; font-weight: 800; margin: 12px 0 14px; letter-spacing: -1.2px; }
.contact-card p { color: #c0cbe6; max-width: 500px; margin: 0 auto 30px; line-height: 1.6; font-size: 17px; }
.contact-cta { display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; }
.contact-cta .btn { padding: 15px 30px; }

/* ---------- footer ---------- */
.footer {
  border-top: 1px solid var(--line-soft);
  padding: 28px 44px;
  display: flex; justify-content: space-between; gap: 16px;
  font-size: 14px; color: var(--muted-3); flex-wrap: wrap;
}
.footer-links { display: flex; gap: 22px; }

/* ============================================================
   Responsive
   ============================================================ */
@media (max-width: 900px) {
  .page { padding: 24px 16px; }
  .nav { padding: 20px 22px; }
  .nav-links {
    display: none; position: absolute; top: 72px; right: 22px; left: 22px;
    flex-direction: column; align-items: flex-start; gap: 18px; z-index: 20;
    background: #0b1020; border: 1px solid var(--line);
    border-radius: 16px; padding: 22px;
  }
  .nav-links.open { display: flex; }
  .nav-links .btn { align-self: stretch; }
  .nav-toggle {
    display: inline-flex; align-items: center; justify-content: center;
    width: 42px; height: 42px; border-radius: 12px;
    background: rgba(255, 255, 255, 0.06); border: 1px solid var(--line);
    color: var(--ink); font-size: 20px; cursor: pointer;
  }
  .hero { padding: 40px 22px 40px; }
  .hero h1 { font-size: 42px; letter-spacing: -1.4px; }
  .hero p { font-size: 17px; }
  .stats { grid-template-columns: repeat(2, 1fr); padding: 0 22px 12px; }
  .section { padding: 28px 22px 44px; }
  .section-head h2 { font-size: 30px; }
  .video-grid { grid-template-columns: 1fr; }
  .about { grid-template-columns: 1fr; gap: 28px; padding: 12px 22px 44px; }
  .about h2 { font-size: 30px; }
  .about-photo { max-width: 360px; margin: 0 auto; }
  .growth-card { padding: 24px; }
  .growth-head { flex-direction: column; align-items: flex-start; }
  .growth-note { text-align: left; }
  .tools h2 { font-size: 28px; }
  .offcam-veil { background: linear-gradient(180deg, rgba(7, 11, 24, 0.55), rgba(7, 11, 24, 0.95)); }
  .offcam-copy { left: 22px; right: 22px; }
  .offcam-copy h2 { font-size: 26px; }
  .contact-card { padding: 40px 24px; }
  .contact-card h2 { font-size: 32px; }
  .footer { flex-direction: column; align-items: center; text-align: center; }
}

@media (max-width: 480px) {
  .hero h1 { font-size: 34px; }
  .stats { grid-template-columns: 1fr; }
}