/* AI SEO — giao diện chung (nền tối kiểu Web3, một theme cố ý) */
:root {
  color-scheme: dark;
  --bg: #060a14;
  --bg-2: #0b1122;
  --glass: rgba(148, 163, 255, 0.05);
  --glass-2: rgba(148, 163, 255, 0.09);
  --line: rgba(148, 163, 255, 0.14);
  --line-2: rgba(148, 163, 255, 0.28);
  --text: #e7eaf6;
  --muted: #8b94b4;
  --faint: #5b6485;
  --violet: #8b5cf6;
  --cyan: #22d3ee;
  --grad: linear-gradient(115deg, #a78bfa 0%, #8b5cf6 35%, #22d3ee 100%);
  --good: #34d399;
  --warn: #fbbf24;
  --bad: #f87171;
  --r-lg: 22px;
  --r-md: 14px;
  --r-sm: 10px;
  --f-head: "Space Grotesk", "Be Vietnam Pro", system-ui, sans-serif;
  --f-body: "Be Vietnam Pro", system-ui, -apple-system, "Segoe UI", sans-serif;
  --f-mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, monospace;
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }
html, body { min-height: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 400 15px/1.6 var(--f-body);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
a { color: inherit; }
button, input { font: inherit; color: inherit; }
:focus-visible { outline: 2px solid var(--cyan); outline-offset: 3px; border-radius: 6px; }

/* ---------- Nền: lưới mạch + quầng sáng + canvas mạng nút ---------- */
.nen { position: fixed; inset: 0; z-index: 0; pointer-events: none; overflow: hidden; }
.nen::before {
  content: ""; position: absolute; inset: -1px;
  background-image:
    linear-gradient(var(--line) 1px, transparent 1px),
    linear-gradient(90deg, var(--line) 1px, transparent 1px);
  background-size: 64px 64px;
  opacity: .35;
  mask-image: radial-gradient(ellipse 80% 60% at 50% 30%, #000 30%, transparent 75%);
}
.blob { position: absolute; border-radius: 50%; }
.blob.a { width: 900px; height: 900px; left: -420px; top: -440px; background: radial-gradient(closest-side, rgba(109,40,217,.45), transparent); }
.blob.b { width: 820px; height: 820px; right: -380px; top: -80px; background: radial-gradient(closest-side, rgba(14,116,144,.42), transparent); }
.blob.c { width: 720px; height: 720px; left: 35%; bottom: -460px; background: radial-gradient(closest-side, rgba(67,56,202,.32), transparent); }
#mang { position: absolute; inset: 0; width: 100%; height: 100%; opacity: .55; }

.khung { position: relative; z-index: 1; padding-inline: 16px; }

/* ---------- Logo ---------- */
.logo { display: inline-flex; align-items: center; gap: 10px; text-decoration: none; }
.logo img, .logo svg { width: 34px; height: 34px; filter: drop-shadow(0 0 10px rgba(139, 92, 246, .55)); }
.logo b { font: 700 19px/1 var(--f-head); letter-spacing: .02em; }
.logo b span { background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }

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

/* ---------- Nút + ô nhập ---------- */
.nut {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  border: 0; cursor: pointer; border-radius: 12px; padding: 12px 18px;
  font-weight: 600; background: var(--grad); color: #060a14;
  box-shadow: 0 0 0 1px rgba(255,255,255,.08) inset, 0 8px 28px -8px rgba(139, 92, 246, .7);
  transition: transform .15s ease, box-shadow .2s ease, filter .2s ease;
}
.nut:hover { transform: translateY(-1px); box-shadow: 0 0 0 1px rgba(255,255,255,.12) inset, 0 12px 34px -8px rgba(34, 211, 238, .65); }
.nut:disabled { filter: grayscale(.6) brightness(.7); cursor: progress; transform: none; }
.nut.phu { background: var(--glass); color: var(--text); box-shadow: 0 0 0 1px var(--line) inset; }
.nut.phu:hover { background: var(--glass-2); box-shadow: 0 0 0 1px var(--line-2) inset; }

.o { display: grid; gap: 6px; }
.o label { font-size: 13px; font-weight: 500; color: var(--muted); }
.o .vo { position: relative; }
.o input {
  width: 100%; padding: 12px 14px; border-radius: 12px;
  background: rgba(6, 10, 20, .6); border: 1px solid var(--line);
  transition: border-color .15s, box-shadow .15s;
}
.o input::placeholder { color: var(--faint); }
.o input:hover { border-color: var(--line-2); }
.o input:focus { outline: none; border-color: var(--violet); box-shadow: 0 0 0 4px rgba(139, 92, 246, .18); }
.o .an-hien {
  position: absolute; right: 6px; top: 50%; transform: translateY(-50%);
  background: none; border: 0; cursor: pointer; color: var(--muted); padding: 8px; border-radius: 8px;
}
.o .an-hien:hover { color: var(--text); }
.o .an-hien svg { width: 18px; height: 18px; display: block; }
.o input.co-nut { padding-right: 44px; }

.bao-loi {
  display: flex; gap: 10px; align-items: flex-start;
  padding: 10px 12px; border-radius: 12px; font-size: 14px;
  background: rgba(248, 113, 113, .08); border: 1px solid rgba(248, 113, 113, .3); color: #fecaca;
}

/* ---------- Badge ---------- */
.badge {
  display: inline-flex; align-items: center; gap: 6px;
  font: 600 11px/1 var(--f-body); letter-spacing: .06em; text-transform: uppercase;
  padding: 6px 10px; border-radius: 999px; border: 1px solid currentColor; white-space: nowrap;
}
.badge i { width: 6px; height: 6px; border-radius: 50%; background: currentColor; box-shadow: 0 0 8px currentColor; }
.badge.xanh { color: var(--good); background: rgba(52, 211, 153, .08); }
.badge.vang { color: var(--warn); background: rgba(251, 191, 36, .08); }
.badge.xam { color: var(--faint); background: transparent; }

.so { font-family: var(--f-mono); font-variant-numeric: tabular-nums; }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation: none !important; transition: none !important; }
}