:root {
  --bg0: #0a0a18;
  --bg1: #14082a;
  --card: rgba(22, 18, 40, 0.92);
  --border: rgba(255, 255, 255, 0.1);
  --text: #eef0ff;
  --muted: rgba(238, 240, 255, 0.6);
  --cyan: #00e5cc;
  --magenta: #e040fb;
  --danger: #ff6b8a;
  --font: "Segoe UI", "Microsoft YaHei", system-ui, sans-serif;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  min-height: 100%;
  font-family: var(--font);
  color: var(--text);
  background: linear-gradient(145deg, var(--bg0), var(--bg1) 60%, #1a0535);
}

.auth-page {
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 24px;
}

.auth-card {
  width: 100%;
  max-width: 420px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 18px;
  padding: 28px 24px 24px;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.35);
}

.auth-brand {
  text-align: center;
  margin-bottom: 22px;
}

.auth-brand h1 {
  margin: 0;
  font-size: 1.35rem;
  background: linear-gradient(90deg, var(--cyan), var(--magenta));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.auth-brand p {
  margin: 8px 0 0;
  font-size: 0.85rem;
  color: var(--muted);
}

.tabs {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
  margin-bottom: 20px;
}

.tab {
  padding: 10px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: transparent;
  color: var(--muted);
  cursor: pointer;
  font-family: inherit;
  font-size: 0.9rem;
}

.tab.active {
  color: var(--text);
  border-color: rgba(0, 229, 204, 0.45);
  background: rgba(0, 229, 204, 0.1);
}

.panel { display: none; }
.panel.active { display: grid; gap: 14px; }

label {
  display: grid;
  gap: 6px;
  font-size: 0.78rem;
  color: var(--muted);
}

input {
  width: 100%;
  padding: 12px 14px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: rgba(0, 0, 0, 0.28);
  color: var(--text);
  font-size: 1rem;
  font-family: inherit;
}

.row-code {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 8px;
}

.btn {
  border: none;
  border-radius: 10px;
  padding: 12px 16px;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  font-family: inherit;
}

.btn-primary {
  background: linear-gradient(90deg, var(--cyan), #5dffde);
  color: #0a0a18;
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.08);
  color: var(--text);
  border: 1px solid var(--border);
  white-space: nowrap;
}

.msg {
  min-height: 1.2em;
  font-size: 0.82rem;
  color: var(--danger);
}

.msg.ok { color: var(--cyan); }

.hint {
  font-size: 0.75rem;
  color: var(--muted);
  line-height: 1.45;
  margin: 0;
}

.back-home {
  display: block;
  text-align: center;
  margin-top: 18px;
  color: var(--muted);
  font-size: 0.82rem;
  text-decoration: none;
}

.back-home:hover { color: var(--cyan); }