/* Kelly CDN — zinc / black theme */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&family=JetBrains+Mono:wght@400;500&display=swap');

:root {
  --bg: #09090b;          /* zinc-950 */
  --bg-soft: #18181b;     /* zinc-900 */
  --card: #18181b;        /* zinc-900 */
  --card-2: #111113;
  --border: #27272a;      /* zinc-800 */
  --border-soft: #1f1f23;
  --text: #fafafa;        /* zinc-50 */
  --text-soft: #e4e4e7;   /* zinc-200 */
  --muted: #a1a1aa;       /* zinc-400 */
  --muted-2: #71717a;     /* zinc-500 */
  --muted-3: #52525b;     /* zinc-600 */
  --danger: #f87171;
  --ok: #4ade80;
  --radius: 12px;
  --shadow: 0 16px 48px rgba(0, 0, 0, 0.5);
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  background-color: var(--bg);
  color: var(--text);
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
}

.font-mono { font-family: 'JetBrains Mono', monospace; }

a { color: var(--text-soft); text-decoration: none; }
a:hover { color: var(--text); }

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 28px;
  border-bottom: 1px solid var(--border);
  background: rgba(9, 9, 11, 0.8);
  backdrop-filter: blur(8px);
  position: sticky;
  top: 0;
  z-index: 10;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 600;
  letter-spacing: -0.2px;
  color: var(--text);
}
.brand svg { width: 20px; height: 20px; color: var(--muted); }
.nav-links { display: flex; gap: 14px; align-items: center; }

.container { max-width: 1040px; margin: 0 auto; padding: 48px 24px; }

.hero { text-align: center; padding: 72px 20px 28px; }
.hero h1 { font-size: clamp(30px, 5.5vw, 50px); margin: 0 0 16px; line-height: 1.08; letter-spacing: -1px; font-weight: 700; }
.hero p { color: var(--muted-2); font-size: 17px; max-width: 600px; margin: 0 auto; line-height: 1.6; }
.muted-accent { color: var(--text-soft); }

.grid { display: grid; gap: 16px; grid-template-columns: repeat(auto-fit, minmax(230px, 1fr)); margin-top: 40px; }
.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 22px;
}
.card h3 { margin: 0 0 8px; font-size: 15px; font-weight: 600; color: var(--text); }
.card p { color: var(--muted-2); margin: 0; font-size: 13.5px; line-height: 1.55; }

.auth-wrap { display: flex; align-items: center; justify-content: center; min-height: calc(100vh - 70px); padding: 24px; }
.auth-card { width: 100%; max-width: 380px; background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); padding: 30px; }
.auth-card h2 { margin: 0 0 6px; font-size: 20px; font-weight: 600; }
.auth-card .sub { color: var(--muted-2); margin: 0 0 22px; font-size: 13.5px; }

label { display: block; font-size: 12.5px; color: var(--muted); margin: 14px 0 6px; }
input {
  width: 100%; padding: 11px 13px; border-radius: 9px;
  border: 1px solid var(--border); background: var(--bg); color: var(--text);
  font-size: 14.5px; outline: none; transition: border-color 0.15s;
  font-family: inherit;
}
input::placeholder { color: var(--muted-3); }
input:focus { border-color: var(--muted-2); }

.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  width: 100%; margin-top: 22px; padding: 12px 16px; border: none; cursor: pointer;
  border-radius: 9px; font-size: 14.5px; font-weight: 600; color: #09090b;
  background: var(--text); font-family: inherit;
  transition: background 0.15s, transform 0.06s;
  text-decoration: none;
}
.btn:hover { background: var(--text-soft); }
.btn:active { transform: translateY(1px); }
.btn.secondary { background: transparent; color: var(--text); border: 1px solid var(--border); }
.btn.secondary:hover { background: var(--bg-soft); }
.btn[disabled] { opacity: 0.55; cursor: not-allowed; }

.btn-ghost {
  padding: 8px 14px; border-radius: 9px; border: 1px solid var(--border);
  background: transparent; color: var(--text); font-weight: 500; font-size: 14px; cursor: pointer;
  font-family: inherit; text-decoration: none; display: inline-flex; align-items: center;
}
.btn-ghost:hover { background: var(--bg-soft); color: var(--text); }

.msg { margin-top: 16px; font-size: 13.5px; min-height: 18px; }
.msg.error { color: var(--danger); }
.msg.ok { color: var(--ok); }

.foot { text-align: center; color: var(--muted-2); margin-top: 18px; font-size: 13.5px; }

/* challenge interstitial */
.challenge { display: flex; align-items: center; justify-content: center; min-height: 100vh; padding: 24px; }
.challenge-inner { text-align: center; max-width: 28rem; padding: 0 24px; }
.shield { width: 48px; height: 48px; margin: 0 auto 24px; color: var(--muted); }
.challenge-inner h1 { font-size: 20px; font-weight: 600; color: var(--text-soft); margin: 0 0 8px; }
.challenge-inner .desc { font-size: 14px; color: var(--muted-2); margin: 0 0 32px; line-height: 1.55; }
.loader { width: 100%; height: 4px; background: var(--border); border-radius: 2px; overflow: hidden; margin-bottom: 16px; }
.loader-bar { height: 100%; width: 0%; background: var(--text); transition: width 0.2s; }
.status { font-size: 12px; color: var(--muted-3); }

.badge { display: inline-block; padding: 4px 11px; border-radius: 999px; font-size: 12px; border: 1px solid var(--border); color: var(--muted); }

.panel { margin-top: 28px; }
.kv { display: flex; justify-content: space-between; padding: 11px 0; border-bottom: 1px solid var(--border-soft); font-size: 14px; }
.kv:last-child { border-bottom: none; }
.kv span:first-child { color: var(--muted-2); }
.kv strong { font-weight: 500; font-family: 'JetBrains Mono', monospace; }

/* ── Mobile Responsive (< 768px) ────────────────────────────────────────────── */
@media (max-width: 767px) {
  .nav {
    padding: 12px 16px;
    flex-wrap: wrap;
    gap: 12px;
  }
  .brand { font-size: 14px; gap: 8px; }
  .brand svg { width: 18px; height: 18px; }
  .nav-links { gap: 8px; font-size: 13px; }

  .container { padding: 24px 16px; max-width: 100%; }
  .hero { padding: 48px 16px 20px; }
  .hero h1 { font-size: clamp(24px, 4vw, 32px); margin-bottom: 12px; }
  .hero p { font-size: 15px; margin-bottom: 20px; }

  .grid {
    gap: 12px;
    grid-template-columns: 1fr;
    margin-top: 28px;
  }
  .card {
    padding: 16px;
  }
  .card h3 { font-size: 14px; margin-bottom: 6px; }
  .card p { font-size: 13px; }

  .auth-wrap { padding: 12px; min-height: calc(100vh - 60px); }
  .auth-card { max-width: 100%; padding: 22px; }
  .auth-card h2 { font-size: 18px; }
  .auth-card .sub { font-size: 13px; margin-bottom: 18px; }

  label { font-size: 12px; margin: 11px 0 5px; }
  input { padding: 10px 11px; font-size: 14px; border-radius: 8px; }
  .btn { margin-top: 18px; padding: 11px 14px; font-size: 14px; }
  .btn-ghost { padding: 7px 12px; font-size: 13px; }

  .challenge { padding: 16px; }
  .challenge-inner { padding: 0 16px; max-width: 90vw; }
  .shield { width: 40px; height: 40px; margin-bottom: 18px; }
  .challenge-inner h1 { font-size: 18px; }
  .challenge-inner .desc { font-size: 13px; margin-bottom: 24px; }

  .panel { margin-top: 20px; }
  .kv { padding: 9px 0; font-size: 13px; }
  .kv strong { font-size: 12px; }
  .badge { padding: 3px 9px; font-size: 11px; }

  .msg { font-size: 13px; }
  .foot { font-size: 12px; margin-top: 14px; }
}

/* ── Tablet (768px - 1024px) ───────────────────────────────────────────────── */
@media (max-width: 1023px) and (min-width: 768px) {
  .container { padding: 36px 20px; }
  .hero { padding: 60px 20px 24px; }
  .hero h1 { font-size: clamp(28px, 5vw, 42px); }

  .grid {
    gap: 14px;
    grid-template-columns: repeat(2, 1fr);
    margin-top: 32px;
  }
  .card { padding: 18px; }
  .card h3 { font-size: 14px; }
  .card p { font-size: 13px; }

  .auth-card { max-width: 340px; padding: 26px; }
  .auth-card h2 { font-size: 18px; }

  .nav-links { gap: 10px; font-size: 14px; }
}