:root {
  --bg: #0b0d12;
  --card: #141824;
  --text: #eef2ff;
  --muted: #96a0b8;
  --line: rgba(255, 255, 255, 0.08);
  --ok: #3ddc97;
  --ok-bg: rgba(61, 220, 151, 0.12);
  --bad: #ff5c7a;
  --bad-bg: rgba(255, 92, 122, 0.12);
  --warn: #ffd166;
  --accent: #5865f2;
  --radius: 18px;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
}

* { box-sizing: border-box; }
body {
  margin: 0;
  min-height: 100vh;
  color: var(--text);
  background:
    radial-gradient(900px 420px at 10% -10%, rgba(88, 101, 242, 0.25), transparent 55%),
    radial-gradient(700px 360px at 100% 0%, rgba(61, 220, 151, 0.08), transparent 50%),
    var(--bg);
}

.wrap {
  width: min(640px, calc(100% - 2rem));
  margin: 0 auto;
  padding: 2.5rem 0 3rem;
}

.hero h1 {
  margin: 0.35rem 0 0.6rem;
  font-size: clamp(1.8rem, 5vw, 2.5rem);
  line-height: 1.15;
}
.eyebrow {
  margin: 0;
  color: var(--accent);
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  font-size: 0.78rem;
}
.lead { margin: 0; color: var(--muted); line-height: 1.55; }
.lead .ok { color: var(--ok); font-weight: 700; }
.lead .bad { color: var(--bad); font-weight: 700; }

.card {
  margin-top: 1.1rem;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.1rem 1.15rem;
  box-shadow: 0 18px 40px rgba(0, 0, 0, 0.28);
}

.form label {
  display: block;
  margin-bottom: 0.45rem;
  color: var(--muted);
  font-size: 0.92rem;
}
.row {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 0.55rem;
}
input {
  width: 100%;
  border: 1px solid var(--line);
  background: #0e121c;
  color: var(--text);
  border-radius: 12px;
  padding: 0.85rem 0.95rem;
  font: inherit;
  outline: none;
}
input:focus {
  border-color: rgba(88, 101, 242, 0.7);
  box-shadow: 0 0 0 3px rgba(88, 101, 242, 0.18);
}
button {
  border: 0;
  border-radius: 12px;
  padding: 0.85rem 1.15rem;
  font: inherit;
  font-weight: 800;
  color: white;
  background: var(--accent);
  cursor: pointer;
  white-space: nowrap;
}
button:hover { filter: brightness(1.08); }
button:disabled { opacity: 0.6; cursor: wait; }
.hint { margin: 0.55rem 0 0; color: var(--muted); font-size: 0.85rem; }

.result { text-align: center; }
.result.hidden { display: none; }
.result.valid {
  border-color: rgba(61, 220, 151, 0.45);
  background: linear-gradient(180deg, rgba(61, 220, 151, 0.08), var(--card));
}
.result.invalid {
  border-color: rgba(255, 92, 122, 0.45);
  background: linear-gradient(180deg, rgba(255, 92, 122, 0.08), var(--card));
}
.result.loading { border-color: rgba(255, 209, 102, 0.35); }

.badge {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 0.35rem 0.7rem;
  border-radius: 999px;
  margin-bottom: 0.6rem;
  background: rgba(255, 255, 255, 0.06);
}
.result.valid .badge { background: var(--ok-bg); color: var(--ok); }
.result.invalid .badge { background: var(--bad-bg); color: var(--bad); }
.result.loading .badge { color: var(--warn); }

#status-text {
  margin: 0.2rem 0 0.45rem;
  font-size: clamp(1.6rem, 5vw, 2.2rem);
}
.result.valid #status-text { color: var(--ok); }
.result.invalid #status-text { color: var(--bad); }

.detail { margin: 0; color: var(--muted); line-height: 1.5; }
.meta {
  margin-top: 1rem;
  display: grid;
  gap: 0.45rem;
  text-align: left;
  background: rgba(0, 0, 0, 0.18);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 0.85rem 0.95rem;
}
.meta.hidden { display: none; }
.meta div {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  font-size: 0.95rem;
}
.meta span { color: var(--muted); }
.meta strong { text-align: right; }

.tips h3 { margin: 0 0 0.5rem; }
.tips ul { margin: 0; padding-left: 1.1rem; color: var(--muted); }
.tips li { margin: 0.35rem 0; }

.foot {
  margin-top: 1.4rem;
  color: var(--muted);
  font-size: 0.85rem;
  text-align: center;
}

@media (max-width: 560px) {
  .row { grid-template-columns: 1fr; }
}