/* =====================================================
   VNOVA AI — Light Theme
   Stack: Bootstrap 5.3 + Custom CSS
   ===================================================== */

/* ---------- Fonts ---------- */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&family=JetBrains+Mono:wght@400;600&display=swap');

/* ---------- Tokens ---------- */
:root {
  --brand:       #1d5fff;
  --brand-dark:  #0d47d4;
  --brand-light: #e8f0ff;
  --accent:      #0bc5ea;
  --bg:          #ffffff;
  --bg-soft:     #f7f9fc;
  --surface:     #ffffff;
  --border:      #e2e8f0;
  --text:        #111827;
  --muted:       #64748b;
  --radius:      12px;
  --radius-lg:   18px;
  --shadow-sm:   0 1px 3px rgba(0,0,0,.08), 0 1px 2px rgba(0,0,0,.06);
  --shadow:      0 4px 16px rgba(0,0,0,.10);
  --shadow-lg:   0 10px 32px rgba(0,0,0,.12);
}

/* ---------- Base ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: 'Inter', system-ui, -apple-system, 'Segoe UI', sans-serif;
  background: var(--bg);
  color: var(--text);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
a { color: var(--brand); text-decoration: none; transition: color .2s; }
a:hover { color: var(--brand-dark); }
img { max-width: 100%; display: block; }
::selection { background: var(--brand); color: #fff; }

/* ---------- Typography ---------- */
h1, h2, h3, h4, h5 { font-weight: 700; letter-spacing: -.015em; color: var(--text); }
h1 { font-size: clamp(2.2rem, 5vw, 3.5rem); line-height: 1.08; }
h2 { font-size: clamp(1.6rem, 3vw, 2.25rem); line-height: 1.18; }
.eyebrow {
  display: inline-flex; align-items: center; gap: 6px;
  font-size: .75rem; font-weight: 700; letter-spacing: .14em;
  text-transform: uppercase; color: var(--brand);
  background: var(--brand-light); border: 1px solid rgba(29,95,255,.18);
  padding: 5px 12px; border-radius: 999px;
}
.lead-muted { color: var(--muted); font-size: 1.1rem; line-height: 1.7; }
.text-gradient {
  background: linear-gradient(135deg, var(--brand), var(--accent));
  -webkit-background-clip: text; background-clip: text; color: transparent;
}

/* ---------- Navbar ---------- */
.navbar-vnova {
  background: rgba(255,255,255,.9);
  backdrop-filter: saturate(180%) blur(12px);
  -webkit-backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid transparent;
  transition: border-color .25s, box-shadow .25s;
}
.navbar-vnova.scrolled {
  border-color: var(--border);
  box-shadow: var(--shadow-sm);
}
.navbar-vnova .navbar-brand {
  display: flex; align-items: center; gap: 10px;
  font-weight: 800; font-size: 1rem; color: var(--text);
  letter-spacing: -.01em;
}
.brand-mark {
  width: 36px; height: 36px; border-radius: 8px;
  background: var(--bg-soft); border: 1px solid var(--border);
  padding: 4px; object-fit: contain;
}
.navbar-vnova .nav-link {
  color: var(--muted) !important;
  font-weight: 500; font-size: .9rem;
  padding: .45rem .8rem !important;
  border-radius: 8px;
  transition: color .2s, background .2s;
}
.navbar-vnova .nav-link:hover,
.navbar-vnova .nav-link.active {
  color: var(--text) !important;
  background: var(--bg-soft);
}
.navbar-vnova .nav-link.active { font-weight: 600; }
.navbar-toggler { border-color: var(--border); }
.navbar-toggler:focus { box-shadow: none; }

/* ---------- Buttons ---------- */
.btn { font-weight: 600; border-radius: 10px; font-size: .9rem; transition: transform .15s, box-shadow .2s; }
.btn:active { transform: translateY(1px); }

.btn-brand {
  background: var(--brand); color: #fff !important;
  border: none; box-shadow: 0 2px 12px rgba(29,95,255,.28);
}
.btn-brand:hover { background: var(--brand-dark); transform: translateY(-1px); box-shadow: 0 6px 20px rgba(29,95,255,.35); }

.btn-outline-brand {
  background: transparent; color: var(--brand) !important;
  border: 1.5px solid var(--brand);
}
.btn-outline-brand:hover { background: var(--brand-light); }

.btn-hf {
  background: var(--brand); color: #fff !important; border: none;
  padding: .55rem 1rem; border-radius: 10px; font-weight: 600; font-size: .88rem;
  display: inline-flex; align-items: center; gap: .5rem;
  transition: background .2s, transform .15s, box-shadow .2s;
  box-shadow: 0 2px 8px rgba(29,95,255,.22);
}
.btn-hf:hover { background: var(--brand-dark); transform: translateY(-1px); }

/* ---------- Hero ---------- */
.hero {
  padding: clamp(100px, 13vw, 160px) 0 clamp(60px, 8vw, 100px);
  background: var(--bg);
  position: relative;
}
.hero::before {
  content: "";
  position: absolute; inset: 0;
  background:
    radial-gradient(800px 500px at 0% 0%, rgba(29,95,255,.06), transparent 70%),
    radial-gradient(600px 400px at 100% 100%, rgba(11,197,234,.06), transparent 70%);
  pointer-events: none;
}
.hero p.lead {
  color: var(--muted); font-size: 1.15rem;
  max-width: 680px; margin: 1.1rem auto 1.8rem;
}
.hero-left { max-width: 640px; }

/* ---------- Stats ---------- */
.stats-bar {
  background: var(--text);
  color: #fff;
  padding: 3rem 0;
}
.stat-item .num { font-size: 2rem; font-weight: 800; color: #fff; }
.stat-item .lbl { font-size: .82rem; color: rgba(255,255,255,.6); margin-top: .2rem; }

/* ---------- Section ---------- */
.section { padding: clamp(60px, 9vw, 100px) 0; }
.section-head { margin-bottom: 3rem; }
.section-head p { color: var(--muted); max-width: 600px; margin: .75rem auto 0; }

/* ---------- Feature card ---------- */
.feature-card {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 2rem;
  height: 100%;
  transition: transform .25s, box-shadow .25s, border-color .25s;
}
.feature-card:hover { transform: translateY(-4px); box-shadow: var(--shadow); border-color: rgba(29,95,255,.25); }
.feature-icon {
  width: 48px; height: 48px; border-radius: 12px;
  background: var(--brand-light); color: var(--brand);
  display: inline-flex; align-items: center; justify-content: center;
  font-size: 1.3rem; margin-bottom: 1rem;
}
.feature-card h3 { font-size: 1.05rem; margin-bottom: .5rem; }
.feature-card p { color: var(--muted); font-size: .9rem; margin: 0; line-height: 1.6; }

/* ---------- Featured dataset ---------- */
.featured-card {
  background: var(--bg-soft); border: 1px solid var(--border);
  border-radius: var(--radius-lg); padding: 1.6rem 2rem;
  display: flex; align-items: center; justify-content: space-between;
  gap: 1.5rem; flex-wrap: wrap;
  transition: box-shadow .25s;
  box-shadow: var(--shadow-sm);
}
.featured-card:hover { box-shadow: var(--shadow); }
.featured-card .badge-latest {
  font-size: .7rem; font-weight: 700; letter-spacing: .1em; text-transform: uppercase;
  color: var(--brand); background: var(--brand-light);
  border: 1px solid rgba(29,95,255,.2); padding: 3px 10px; border-radius: 999px;
  display: inline-block; margin-bottom: 6px;
}
.featured-card h3 { font-size: 1.05rem; margin: .2rem 0 .3rem; word-break: break-word; }
.featured-card .meta { color: var(--muted); font-size: .85rem; }

/* ---------- Dataset grid ---------- */
.dataset-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(310px, 1fr)); gap: 1.2rem; }

.dataset-card {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 0; overflow: hidden;
  display: flex; flex-direction: column;
  transition: transform .2s, box-shadow .2s, border-color .2s;
}
.dataset-card:hover { transform: translateY(-3px); box-shadow: var(--shadow); border-color: rgba(29,95,255,.3); }
.dataset-card-body { padding: 1.4rem; flex: 1; }
.dataset-card-footer { padding: 1rem 1.4rem; background: var(--bg-soft); border-top: 1px solid var(--border); margin-top: auto; }
.dataset-card .tag {
  font-size: .7rem; font-weight: 700; letter-spacing: .08em; text-transform: uppercase;
  color: var(--brand); background: var(--brand-light);
  border: 1px solid rgba(29,95,255,.2); padding: 3px 10px; border-radius: 999px;
  display: inline-block; margin-bottom: .8rem;
}
.dataset-card h3 { font-size: .95rem; line-height: 1.4; margin: 0 0 .4rem; word-break: break-word; }
.dataset-card .meta { color: var(--muted); font-size: .84rem; margin: 0; }
.format-pill {
  font-family: 'JetBrains Mono', monospace; font-size: .7rem;
  background: #f1f5f9; color: #475569; border: 1px solid #e2e8f0;
  padding: 2px 8px; border-radius: 6px; display: inline-block; margin-bottom: .5rem;
}

/* ---------- Search ---------- */
.search-wrap { position: relative; max-width: 500px; }
.search-wrap input {
  width: 100%; padding: .75rem 1rem .75rem 2.6rem;
  border: 1.5px solid var(--border); border-radius: 10px;
  font-size: .95rem; color: var(--text); background: #fff;
  transition: border-color .2s, box-shadow .2s;
}
.search-wrap input:focus {
  outline: none; border-color: var(--brand);
  box-shadow: 0 0 0 3px rgba(29,95,255,.12);
}
.search-wrap .search-icon {
  position: absolute; left: .9rem; top: 50%; transform: translateY(-50%);
  color: var(--muted); pointer-events: none;
}
.search-wrap input::placeholder { color: #94a3b8; }

/* ---------- Code block ---------- */
.code-wrap {
  background: #0d1117; border: 1px solid #30363d;
  border-radius: var(--radius); overflow: hidden;
}
.code-header {
  background: #161b22; border-bottom: 1px solid #30363d;
  padding: .6rem 1rem; display: flex; align-items: center; justify-content: space-between;
}
.code-header span { font-family: 'JetBrains Mono', monospace; font-size: .75rem; color: #8b949e; }
.copy-btn {
  background: none; border: none; color: #8b949e; cursor: pointer; padding: 4px;
  border-radius: 6px; transition: color .2s, background .2s; font-size: .78rem;
  display: inline-flex; align-items: center; gap: 5px;
}
.copy-btn:hover { color: #e6edf3; background: rgba(255,255,255,.08); }
.code-wrap pre {
  margin: 0; padding: 1.2rem 1.4rem; overflow-x: auto;
  font-family: 'JetBrains Mono', monospace; font-size: .85rem;
  color: #c9d1d9; line-height: 1.65;
}
.c-com { color: #8b949e; font-style: italic; }
.c-key { color: #ff7b72; }
.c-str { color: #a5d6ff; }
.c-fn  { color: #d2a8ff; }

/* ---------- About cards ---------- */
.about-card {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 2rem; height: 100%;
  transition: box-shadow .25s, border-color .25s;
}
.about-card:hover { box-shadow: var(--shadow); border-color: rgba(29,95,255,.2); }
.about-card .card-label {
  font-size: .72rem; font-weight: 700; letter-spacing: .12em; text-transform: uppercase;
  color: var(--brand); margin-bottom: .75rem; display: flex; align-items: center; gap: 6px;
}
.about-card h3 { font-size: 1.15rem; margin-bottom: .5rem; }
.about-card p { color: var(--muted); line-height: 1.7; margin: 0; }

/* ---------- Contact ---------- */
.contact-card {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius-lg); padding: 2.5rem;
  box-shadow: var(--shadow-sm);
}
.form-label { font-size: .85rem; font-weight: 600; color: var(--text); }
.form-control {
  border: 1.5px solid var(--border); border-radius: 10px;
  font-size: .92rem; color: var(--text); padding: .7rem 1rem;
  transition: border-color .2s, box-shadow .2s;
}
.form-control:focus {
  border-color: var(--brand);
  box-shadow: 0 0 0 3px rgba(29,95,255,.12);
  color: var(--text);
}
.form-control::placeholder { color: #94a3b8; }
.contact-info-item { display: flex; align-items: flex-start; gap: 1rem; padding: 1rem 0; border-bottom: 1px solid var(--border); }
.contact-info-item:last-child { border-bottom: none; }
.contact-icon {
  width: 42px; height: 42px; border-radius: 10px;
  background: var(--brand-light); color: var(--brand);
  display: inline-flex; align-items: center; justify-content: center;
  font-size: 1.1rem; flex-shrink: 0;
}
.contact-info-item .label { font-size: .78rem; font-weight: 600; color: var(--muted); text-transform: uppercase; letter-spacing: .08em; }
.contact-info-item .value { font-weight: 500; color: var(--text); font-size: .95rem; }
.contact-info-item a.value { color: var(--brand); }
.contact-info-item a.value:hover { color: var(--brand-dark); }

/* ---------- Page header ---------- */
.page-header {
  background: var(--bg-soft); border-bottom: 1px solid var(--border);
  padding: clamp(90px, 11vw, 130px) 0 clamp(40px, 5vw, 64px);
  position: relative;
}
.page-header::before {
  content: "";
  position: absolute; inset: 0;
  background: radial-gradient(700px 400px at 0% 0%, rgba(29,95,255,.05), transparent 70%);
  pointer-events: none;
}
.page-header p.lead { color: var(--muted); max-width: 640px; font-size: 1.1rem; margin-top: .75rem; }

/* ---------- Empty state ---------- */
#dataset-empty { display: none; }

/* ---------- Mission section ---------- */
.mission-section { background: var(--bg-soft); border-top: 1px solid var(--border); }
.check-list li {
  display: flex; align-items: flex-start; gap: .75rem;
  color: var(--text); font-weight: 500; padding: .4rem 0;
}
.check-list li::before {
  content: "✓";
  display: inline-flex; align-items: center; justify-content: center;
  width: 22px; height: 22px; border-radius: 50%;
  background: var(--brand-light); color: var(--brand);
  font-size: .8rem; font-weight: 700; flex-shrink: 0; margin-top: 1px;
}

/* ---------- Footer ---------- */
.footer {
  background: var(--bg-soft); border-top: 1px solid var(--border);
  padding: 4rem 0 2rem; margin-top: 5rem;
}
.footer h5 { font-size: .85rem; font-weight: 700; letter-spacing: .08em; text-transform: uppercase; color: var(--text); margin-bottom: 1.1rem; }
.footer a { color: var(--muted); font-size: .88rem; display: inline-block; padding: .2rem 0; transition: color .2s; }
.footer a:hover { color: var(--brand); }
.social-links { display: flex; gap: .75rem; }
.social-link {
  width: 38px; height: 38px; border-radius: 9px;
  background: var(--surface); border: 1px solid var(--border);
  display: inline-flex; align-items: center; justify-content: center;
  color: var(--muted); font-size: 1rem;
  transition: transform .2s, background .2s, border-color .2s, color .2s;
}
.social-link:hover { transform: translateY(-2px); background: var(--brand); border-color: var(--brand); color: #fff !important; }
.footer-copy {
  border-top: 1px solid var(--border); padding-top: 1.5rem; margin-top: 2.5rem;
  text-align: center; color: var(--muted); font-size: .82rem;
}

/* ---------- Responsive ---------- */
@media (max-width: 768px) {
  .dataset-grid { grid-template-columns: 1fr; }
  .featured-card { flex-direction: column; }
  .stat-item { border-right: none !important; padding-right: 0 !important; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation: none !important; transition: none !important; }
}