:root {
  --bg: #080d13;
  --panel: #0f171f;
  --line: #22303e;
  --text: #dbe4ee;
  --muted: #7d8b9b;
  --blue: #4f9cf9;
  --red: #ef5350;
  --green: #26a69a;
}
* { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0;
  color: var(--text);
  font-family: "Segoe UI", "Microsoft YaHei", system-ui, -apple-system, sans-serif;
  background:
    radial-gradient(900px 520px at 18% 6%, rgba(79, 156, 249, .16), transparent 62%),
    radial-gradient(700px 480px at 88% 92%, rgba(38, 166, 154, .10), transparent 60%),
    linear-gradient(160deg, #080d13 0%, #0b1219 52%, #070b10 100%);
  display: grid;
  place-items: center;
  padding: 24px;
}
.login-wrap { width: min(440px, 100%); }
.login-card {
  background: linear-gradient(180deg, rgba(18, 27, 37, .96), rgba(12, 19, 27, .98));
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 28px 28px 20px;
  box-shadow: 0 30px 80px rgba(0, 0, 0, .55);
  animation: enter .35s ease-out both;
}
@keyframes enter {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}
.brand { display: flex; align-items: center; gap: 13px; }
.brand-mark {
  width: 42px; height: 42px; border-radius: 11px;
  display: grid; place-items: center;
  color: #fff; font-weight: 800; font-size: 19px;
  background: linear-gradient(135deg, #4f9cf9, #2f6fc0);
  box-shadow: 0 8px 22px rgba(79, 156, 249, .28);
}
.eyebrow {
  color: #6f8297; font-size: 9px; letter-spacing: .14em;
  font-family: ui-monospace, Consolas, monospace;
}
h1 { margin: 3px 0 0; font-size: 23px; letter-spacing: .02em; }
.login-sub { color: var(--muted); font-size: 12px; line-height: 1.65; margin: 16px 0 20px; }
.field { display: block; margin-bottom: 13px; }
.field span { display: block; color: #9aa9ba; font-size: 12px; margin-bottom: 6px; }
.field input {
  width: 100%; height: 42px; padding: 8px 12px;
  color: var(--text); background: #0a1118;
  border: 1px solid #263544; border-radius: 9px;
  font-size: 14px; outline: none;
  transition: border-color .16s, box-shadow .16s;
}
.field input:focus {
  border-color: rgba(79, 156, 249, .72);
  box-shadow: 0 0 0 3px rgba(79, 156, 249, .12);
}
.login-error {
  min-height: 18px; margin: 2px 0 8px;
  color: #ff9b9d; font-size: 12px; line-height: 1.5;
}
.login-error:empty { display: none; }
.login-btn {
  width: 100%; height: 44px; margin-top: 2px;
  border: 0; border-radius: 9px; cursor: pointer;
  color: #fff; font-size: 14px; font-weight: 650; letter-spacing: .04em;
  background: linear-gradient(135deg, #4f9cf9, #2f6fc0);
  box-shadow: 0 10px 26px rgba(47, 111, 192, .3);
  transition: filter .16s, transform .16s;
}
.login-btn:hover { filter: brightness(1.08); }
.login-btn:active { transform: translateY(1px); }
.login-foot {
  display: flex; justify-content: space-between; gap: 10px;
  margin-top: 18px; padding-top: 14px;
  border-top: 1px solid rgba(34, 48, 62, .8);
  color: #637383; font-size: 10px; line-height: 1.6;
}
@media (max-width: 480px) {
  body { padding: 14px; }
  .login-card { padding: 22px 18px 16px; border-radius: 13px; }
  .login-foot { flex-direction: column; gap: 2px; }
}