:root {
  --bg: #f4f7fb;
  --surface: rgba(255, 255, 255, 0.92);
  --line: #e2e8f0;
  --text: #0f172a;
  --muted: #64748b;
  --primary: #0f172a;
  --danger: #b91c1c;
  --shadow: 0 20px 50px rgba(15, 23, 42, 0.1);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 24px;
  font-family: "Noto Sans SC", sans-serif;
  color: var(--text);
  background:
    radial-gradient(circle at top left, rgba(148, 163, 184, 0.18), transparent 22%),
    linear-gradient(180deg, #f8fafc 0%, #eef2f7 100%);
}

.login-shell {
  width: min(460px, 100%);
}

.login-card {
  padding: 30px;
  border: 1px solid var(--line);
  border-radius: 28px;
  background: var(--surface);
  box-shadow: var(--shadow);
}

.eyebrow {
  margin: 0 0 10px;
  color: var(--muted);
  font-size: 0.82rem;
  font-weight: 800;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

h1 {
  margin: 0;
  font-size: 2rem;
}

.login-copy {
  margin: 12px 0 0;
  color: var(--muted);
}

.login-form {
  display: grid;
  gap: 16px;
  margin-top: 24px;
}

.login-form label {
  display: grid;
  gap: 8px;
}

.login-form input {
  width: 100%;
  padding: 12px 14px;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: #fff;
  color: var(--text);
}

.login-btn {
  padding: 13px 16px;
  border: 0;
  border-radius: 16px;
  background: var(--primary);
  color: #fff;
  font: inherit;
  font-weight: 700;
  cursor: pointer;
}

.login-error {
  min-height: 20px;
  margin: 0;
  color: var(--danger);
  font-size: 0.92rem;
}