:root {
  color-scheme: dark;
  --bg: #071018;
  --panel: rgba(13, 25, 36, .94);
  --line: rgba(139, 173, 204, .22);
  --text: #edf6ff;
  --muted: #91a9bf;
  --brand: #55e6c2;
  --danger: #ff8b98;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  color: var(--text);
  background:
    radial-gradient(circle at 18% 18%, rgba(35, 140, 145, .22), transparent 28rem),
    radial-gradient(circle at 88% 14%, rgba(48, 101, 170, .2), transparent 32rem),
    var(--bg);
  font-family: Inter, "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
}

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

.login-card {
  width: min(390px, 100%);
  padding: 32px;
  border: 1px solid var(--line);
  border-radius: 22px;
  background: var(--panel);
  box-shadow: 0 28px 80px rgba(0, 0, 0, .38);
}

.brand-mark {
  width: 42px;
  height: 42px;
  display: grid;
  place-items: center;
  border-radius: 13px;
  color: #052219;
  background: linear-gradient(145deg, #7bf1d2, #23c7a2);
  font-weight: 900;
  font-size: 20px;
}

.eyebrow {
  margin: 22px 0 7px;
  color: var(--brand);
  font-size: 11px;
  font-weight: 800;
  letter-spacing: .16em;
}

h1 { margin: 0; font-size: 25px; letter-spacing: -.03em; }
.intro, .security-note { color: var(--muted); line-height: 1.6; }
.intro { margin: 9px 0 25px; font-size: 13px; }
.security-note { margin: 18px 0 0; font-size: 11px; text-align: center; }

form { display: grid; gap: 14px; }
label { display: grid; gap: 7px; }
label span { color: #c9dae9; font-size: 12px; font-weight: 700; }
input {
  width: 100%;
  height: 44px;
  padding: 0 13px;
  border: 1px solid var(--line);
  border-radius: 11px;
  outline: none;
  color: var(--text);
  background: #09151f;
  font: inherit;
}
input:focus { border-color: rgba(85, 230, 194, .68); box-shadow: 0 0 0 3px rgba(85, 230, 194, .09); }
button {
  height: 44px;
  border: 0;
  border-radius: 11px;
  color: #052219;
  background: linear-gradient(145deg, #69eccb, #23c7a2);
  font-family: inherit;
  font-size: 14px;
  font-weight: 800;
  cursor: pointer;
}
button:disabled { opacity: .58; cursor: wait; }
.login-message { min-height: 18px; margin: -2px 0; color: var(--danger); font-size: 12px; }

@media (max-width: 480px) {
  .login-shell { padding: 14px; }
  .login-card { padding: 25px 20px; border-radius: 18px; }
}