:root {
  --bg: #070b12;
  --bg-2: #0b1220;
  --surface: #0e1726;
  --surface-2: #131f33;
  --border: #1c2a40;
  --accent: #22c55e;
  --accent-2: #14b8a6;
  --text: #e9eef7;
  --muted: #8b9bb4;
  --muted-2: #64748b;
  --danger: #ef4444;
  --radius: 12px;
  /* compatibility aliases — referenced by app.js inline styles & index.html inline styles */
  --red: var(--danger);
  --panel: var(--surface);
  --panel-2: var(--surface-2);
  --green: var(--accent);
  --green-dim: #15803d;
  --amber: #f59e0b;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: -apple-system, "Segoe UI", Roboto, "PingFang SC", "Microsoft YaHei", sans-serif;
  background-color: var(--bg);
  background-image:
    radial-gradient(1200px 600px at 85% -10%, rgba(20, 184, 166, 0.09), transparent 60%),
    radial-gradient(900px 500px at -5% 0%, rgba(34, 197, 94, 0.07), transparent 55%);
  color: var(--text);
  font-size: 14px;
  -webkit-font-smoothing: antialiased;
}

button { font-family: inherit; }

/* ── header ─────────────────────────────────────────── */
header {
  display: flex;
  align-items: center;
  gap: 18px;
  padding: 12px 24px;
  background: linear-gradient(180deg, var(--bg-2), var(--surface));
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 10;
  backdrop-filter: blur(8px);
}

.back-link {
  color: var(--muted);
  text-decoration: none;
  font-size: 13px;
  padding: 6px 12px;
  border: 1px solid var(--border);
  border-radius: 8px;
  white-space: nowrap;
  transition: color .15s, border-color .15s, background .15s;
}
.back-link:hover { color: var(--accent); border-color: var(--accent); background: rgba(34, 197, 94, .07); }

.logo { font-size: 18px; font-weight: 700; color: var(--accent); }
.logo .zh { font-size: 13px; color: var(--muted); font-weight: 400; margin-left: 2px; }

nav { display: flex; gap: 6px; }
.tab-btn {
  background: transparent;
  border: 1px solid transparent;
  color: var(--muted);
  padding: 8px 14px;
  border-radius: 8px;
  cursor: pointer;
  font-size: 14px;
  transition: color .15s, background .15s, border-color .15s;
}
.tab-btn:hover { color: var(--text); background: var(--surface); }
.tab-btn.active {
  background: var(--surface-2);
  color: var(--accent);
  border-color: var(--border);
  box-shadow: inset 0 -2px 0 var(--accent);
}

.acct-status {
  margin-left: auto;
  color: var(--muted);
  font-size: 13px;
  padding: 4px 14px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--surface);
  white-space: nowrap;
}

/* ── layout ─────────────────────────────────────────── */
main { padding: 24px 20px; max-width: 1200px; margin: 0 auto; }

.tab { display: none; }
.tab.active { display: block; animation: fade .2s ease; }
@keyframes fade { from { opacity: 0; transform: translateY(4px); } to { opacity: 1; transform: none; } }

h2 { font-size: 20px; margin: 0 0 16px; }
h3 { font-size: 15px; margin: 0 0 12px; color: var(--accent); }

.panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, .02);
}

/* ── tables ─────────────────────────────────────────── */
table { width: 100%; border-collapse: collapse; }
th, td {
  text-align: left;
  padding: 10px 12px;
  border-bottom: 1px solid var(--border);
  font-variant-numeric: tabular-nums;
}
th {
  color: var(--muted-2);
  font-weight: 600;
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: .4px;
}
td { font-size: 13px; }
tbody tr { transition: background .12s; }
tbody tr:hover { background: var(--surface-2); }

/* ── trade / account grids ──────────────────────────── */
.trade-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.account-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; align-items: start; }
.panel.wide { grid-column: 1 / -1; }
.trade-head { display: flex; justify-content: space-between; align-items: center; margin-bottom: 14px; flex-wrap: wrap; gap: 8px; }

.ticker {
  font-size: 24px;
  font-weight: 700;
  color: var(--accent);
  font-family: ui-monospace, "SF Mono", "JetBrains Mono", "Cascadia Code", Menlo, Consolas, monospace;
  font-variant-numeric: tabular-nums;
}
.ticker .sub { font-size: 13px; color: var(--muted); font-weight: 400; font-family: inherit; }

.orderbook-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
  padding: 5px 8px;
  font-variant-numeric: tabular-nums;
  font-family: ui-monospace, "SF Mono", "JetBrains Mono", Menlo, Consolas, monospace;
  border-radius: 6px;
}
.orderbook-row.head { color: var(--muted-2); font-size: 12px; border-bottom: 1px solid var(--border); margin-bottom: 4px; font-family: inherit; }
.ob-ask .price { color: var(--danger); }
.ob-bid .price { color: var(--accent); }

/* ── forms ──────────────────────────────────────────── */
.order-form { display: flex; flex-direction: column; gap: 10px; }
.order-form label { font-size: 12px; color: var(--muted); }

input, select, textarea {
  background: var(--surface-2);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 9px 12px;
  border-radius: 8px;
  font-size: 14px;
  font-family: inherit;
  transition: border-color .15s, box-shadow .15s;
}
input:focus, select:focus, textarea:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(34, 197, 94, 0.15);
}
input::placeholder, textarea::placeholder { color: var(--muted-2); }
input[type="number"] { font-family: ui-monospace, "SF Mono", Menlo, Consolas, monospace; font-variant-numeric: tabular-nums; }

.seg { display: flex; gap: 6px; }
.side-btn, .type-btn {
  flex: 1;
  padding: 9px;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: var(--surface-2);
  color: var(--muted);
  cursor: pointer;
  font-weight: 600;
  transition: all .15s;
}
.side-btn:hover, .type-btn:hover { color: var(--text); border-color: var(--muted-2); }
.side-btn.buy.active {
  background: linear-gradient(135deg, rgba(34, 197, 94, .28), rgba(20, 184, 166, .2));
  color: #fff;
  border-color: var(--accent);
  box-shadow: inset 0 0 0 1px var(--accent);
}
.side-btn.sell.active {
  background: linear-gradient(135deg, rgba(239, 68, 68, .28), rgba(239, 68, 68, .16));
  color: #fff;
  border-color: var(--danger);
  box-shadow: inset 0 0 0 1px var(--danger);
}
.type-btn.active {
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: #04170f;
  border-color: transparent;
}

.primary {
  background: linear-gradient(135deg, #22c55e, #14b8a6);
  color: #04170f;
  border: none;
  padding: 11px 16px;
  border-radius: 8px;
  cursor: pointer;
  font-size: 14px;
  font-weight: 700;
  box-shadow: 0 2px 10px rgba(34, 197, 94, .2);
  transition: filter .15s, box-shadow .15s, transform .1s;
}
.primary:hover { filter: brightness(1.08); box-shadow: 0 4px 16px rgba(34, 197, 94, .32); }
.primary:active { transform: translateY(1px); }

/* ── misc ───────────────────────────────────────────── */
.msg { font-size: 13px; min-height: 18px; }
.msg.err { color: var(--danger); }
.msg.ok { color: var(--accent); }

.big { font-size: 20px; font-weight: 700; font-variant-numeric: tabular-nums; }
.muted { color: var(--muted); }
.hint { font-size: 12px; color: var(--muted-2); }
.hidden { display: none; }

.badge {
  display: inline-block;
  padding: 2px 10px;
  border-radius: 999px;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: .3px;
}
.tier-A { background: rgba(59, 130, 246, .18); color: #93c5fd; border: 1px solid rgba(59, 130, 246, .4); }
.tier-B { background: rgba(14, 165, 233, .16); color: #7dd3fc; border: 1px solid rgba(14, 165, 233, .4); }
.tier-C { background: rgba(34, 197, 94, .16); color: #86efac; border: 1px solid rgba(34, 197, 94, .4); }
.tier-D { background: rgba(100, 116, 139, .2); color: #cbd5e1; border: 1px solid rgba(100, 116, 139, .4); }

button.link {
  background: none;
  border: none;
  color: var(--accent);
  cursor: pointer;
  font-size: 13px;
  font-weight: 600;
  padding: 4px 10px;
  border-radius: 6px;
  transition: background .12s;
}
button.link:hover { text-decoration: none; background: rgba(34, 197, 94, .1); }

footer {
  text-align: center;
  color: var(--muted-2);
  font-size: 12px;
  padding: 20px;
  border-top: 1px solid var(--border);
  margin-top: 30px;
}

/* ── scrollbar / responsive ─────────────────────────── */
::-webkit-scrollbar { width: 10px; height: 10px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 8px; }
::-webkit-scrollbar-thumb:hover { background: var(--muted-2); }

@media (max-width: 900px) {
  .trade-grid, .account-grid { grid-template-columns: 1fr; }
  header { flex-wrap: wrap; }
  .acct-status { margin-left: 0; }
}