/* ---------- THEME ---------- */
:root {
  --bg: #0b0f10;
  --bg-soft: #0f1417;
  --text: #e6f1ff;
  --muted: #9fb0c0;
  --neon: #39ff14;
  --neon-soft: #2bff1466;
  --card: #11171a;
  --border: #1c242a;
  --link: #9dffcc;
  --radius: 14px;
  --shadow: 0 0 22px var(--neon-soft), 0 0 4px var(--neon-soft);
  --container: min(1100px, 92vw);
}

:root.light {
  --bg: #ffffff;
  --bg-soft: #f6faf7;
  --text: #0a0b0c;
  --muted: #4a575f;
  --neon: #16a34a;
  --neon-soft: #16a34a44;
  --card: #ffffff;
  --border: #e4efe7;
  --link: #0d9488;
  --shadow: none;
}

/* ---------- BASE ---------- */
* { box-sizing: border-box; }
html, body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 400 clamp(14px, 1.6vw, 16px)/1.6 ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, Arial, "Noto Sans Bengali", "Bangla", sans-serif;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
a { color: var(--link); text-decoration: none; }
a:hover { text-decoration: underline; }
.container { width: var(--container); margin-inline: auto; padding-inline: max(16px, env(safe-area-inset-left)); }

/* ---------- HEADER (NO OVERLAP) ---------- */
header {
  position: sticky; top: 0; z-index: 50;
  background: color-mix(in oklab, var(--bg) 88%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
  padding-top: env(safe-area-inset-top);
}

.nav {
  display: grid;
  grid-template-columns: 1fr auto; /* mobile: brand | actions */
  grid-template-rows: auto auto;   /* row-1: bar, row-2: menu */
  gap: 8px 12px;
  align-items: center;
  min-height: 64px;
  padding-block: 8px;
}
.brand {
  display: inline-flex; align-items: center; gap: 10px; font-weight: 800;
  font-size: clamp(16px, 2.4vw, 18px);
}
.brand .dot { width: 10px; height: 10px; border-radius: 50%; background: var(--neon); box-shadow: var(--shadow); }

.actions {
  justify-self: end;
  display: inline-flex; gap: 8px;
}
.icon-btn {
  width: 42px; height: 42px;
  display: inline-flex; justify-content: center; align-items: center;
  background: var(--bg-soft); border: 1px solid var(--border);
  border-radius: 12px; cursor: pointer;
}
.hamburger { display: inline-flex; }

.menu {
  grid-column: 1 / -1; /* mobile: full width row */
  display: none;
  gap: 8px; padding: 8px;
  background: var(--bg); border: 1px solid var(--border);
  border-radius: 12px;
}
.menu.open { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); }
.menu a {
  padding: 10px 12px; border-radius: 10px; text-align: center; color: var(--text);
  border: 1px solid transparent;
}
.menu a:hover, .menu a.active {
  border-color: color-mix(in oklab, var(--neon) 45%, var(--border));
  background: color-mix(in oklab, var(--neon) 12%, var(--bg-soft));
  box-shadow: var(--shadow);
}

/* desktop header */
@media (min-width: 900px) {
  .nav {
    grid-template-columns: auto 1fr auto; /* brand | menu | actions */
    grid-template-rows: auto;
  }
  .menu { 
    display: inline-flex !important; 
    grid-column: 2 / 3; background: transparent; border: none; padding: 0; 
  }
  .menu a { padding: 8px 10px; }
  .hamburger { display: none; }
}

/* ---------- HERO ---------- */
.hero {
  padding-block: clamp(32px, 6vw, 72px) 24px;
  border-bottom: 1px dashed var(--border);
  background:
    radial-gradient(600px 200px at 50% -10%, color-mix(in oklab, var(--neon) 8%, transparent), transparent 70%) no-repeat;
}
.hero h1 { font-size: clamp(22px, 4.5vw, 36px); margin: 6px 0 8px; letter-spacing: .2px; }
.hero p { margin: 0; color: var(--muted); max-width: 72ch; }
.pill {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 6px 10px; border-radius: 999px; border: 1px solid var(--border);
  background: color-mix(in oklab, var(--neon) 8%, var(--bg-soft));
  box-shadow: inset 0 0 0 1px color-mix(in oklab, var(--neon) 18%, transparent);
  color: var(--text); font-weight: 700;
}
.dot-neon { width: 6px; height: 6px; border-radius: 50%; background: var(--neon); box-shadow: var(--shadow); }
.cta { margin-top: 18px; display: flex; gap: 10px; flex-wrap: wrap; }
.btn {
  padding: 10px 14px; border-radius: 12px; border: 1px solid var(--border);
  background: linear-gradient(to bottom right, color-mix(in oklab, var(--neon) 12%, var(--card)), var(--card));
  color: var(--text); font-weight: 700; box-shadow: var(--shadow);
}
.btn.ghost { background: var(--bg-soft); box-shadow: none; }

/* ---------- GRID/CARDS ---------- */
.grid {
  display: grid;
  gap: 16px;
  grid-template-columns: repeat(auto-fit, minmax(min(280px, 100%), 1fr));
  padding-block: 28px 44px;
}
.card {
  background: var(--card); border: 1px solid var(--border);
  border-radius: var(--radius); padding: clamp(14px, 2.6vw, 20px);
  transition: transform .15s ease, box-shadow .15s ease;
}
.card:hover { transform: translateY(-2px); box-shadow: var(--shadow); }
.card-full { grid-column: 1 / -1; }

/* ---------- FOOTER ---------- */
footer {
  border-top: 1px solid var(--border);
  padding: 20px 0 max(24px, env(safe-area-inset-bottom));
  color: var(--muted);
  background: linear-gradient(to bottom, transparent, color-mix(in oklab, var(--bg) 85%, #000));
}
.foot-inner { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 10px; }
.foot-links { display: flex; gap: 14px; flex-wrap: wrap; }
.tiny { font-size: 12px; }

/* ---------- ACCESSIBILITY ---------- */
@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; animation: none !important; }
}


/* --- Ensure header icons visible in both themes --- */
header .icon-btn, header .icon-btn svg { color: var(--fg, #e6edf3); fill: currentColor; stroke: currentColor; }
header .brand { color: var(--fg, #e6edf3); }

.grid-3 { display:grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap:1rem; }
.card { border: 1px solid var(--border, #1f2a2e); border-radius: 12px; background: var(--surface, #0f1416); }
.card-body { padding: 1rem; }
.btn { padding: .6rem 1rem; border-radius: 10px; border:1px solid var(--border, #1f2a2e); text-decoration:none; display:inline-block }
.btn:hover { transform: translateY(-1px); }
.muted { opacity:.75; }