:root {
  --bg: #f4f7fb;
  --card: #fff;
  --text: #0f172a;
  --muted: #64748b;
  --line: #e2e8f0;
  --primary: #1d4ed8;
  --primary-2: #2563eb;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  background: linear-gradient(180deg, #dbeafe 0%, var(--bg) 220px);
  color: var(--text);
  min-height: 100vh;
}
.hidden { display: none !important; }
.panel, .card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 18px;
  box-shadow: 0 8px 24px rgba(15, 23, 42, 0.04);
}
.login-panel {
  width: min(420px, calc(100% - 32px));
  margin: 10vh auto;
}
.login-panel h1 { margin: 0 0 4px; font-size: 1.6rem; }
.sub, .muted, .hint, .d { color: var(--muted); font-size: 0.9rem; }
label { display: block; margin: 12px 0 6px; font-size: 0.9rem; }
input, select, textarea {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid var(--line);
  border-radius: 10px;
  font: inherit;
}
button {
  border: 0;
  border-radius: 10px;
  padding: 10px 14px;
  font: inherit;
  cursor: pointer;
}
button.primary { background: var(--primary); color: #fff; margin-top: 14px; }
button.secondary { background: #e2e8f0; color: var(--text); margin-top: 14px; margin-left: 8px; }
button.ghost { background: transparent; color: var(--muted); }
.err { color: #b91c1c; min-height: 1.2em; }
.links { margin-top: 18px; }
.top {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  align-items: center;
  padding: 14px 18px;
  background: rgba(255,255,255,0.9);
  border-bottom: 1px solid var(--line);
  position: sticky;
  top: 0;
  backdrop-filter: blur(8px);
  z-index: 5;
}
.top nav { display: flex; flex-wrap: wrap; gap: 6px; }
.tab {
  background: transparent;
  color: var(--muted);
  padding: 8px 10px;
}
.tab.on { background: #dbeafe; color: var(--primary); font-weight: 600; }
.tabpane { width: min(1100px, calc(100% - 32px)); margin: 18px auto; }
.cards {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
  margin-bottom: 14px;
}
.cards .card .k { color: var(--muted); font-size: 0.85rem; }
.cards .card .v { font-size: 1.4rem; font-weight: 700; margin-top: 6px; }
.list { margin-top: 12px; }
.item {
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 12px;
  margin-bottom: 8px;
  background: #fff;
}
.item strong { display: block; margin-bottom: 4px; }
.tier-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 12px;
  margin-top: 12px;
}
.tier {
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 14px;
}
.tier .price { font-size: 1.35rem; font-weight: 700; margin: 8px 0; }
.tier.current { outline: 2px solid var(--primary-2); }
.row { display: flex; gap: 8px; align-items: center; }
.row input { flex: 1; }
@media (max-width: 900px) {
  .cards, .tier-grid { grid-template-columns: 1fr 1fr; }
  .top { flex-direction: column; align-items: flex-start; }
}
@media (max-width: 560px) {
  .cards, .tier-grid { grid-template-columns: 1fr; }
}