:root {
  color-scheme: light;
  --bg-a: #eef4ff;
  --bg-b: #f7f9fc;
  --ink: #172033;
  --muted: #667085;
  --line: #dce4f0;
  --brand: #2563eb;
  --brand-dark: #1d4ed8;
  --success: #087d59;
  --danger: #b42318;
}

* { box-sizing: border-box; }

html, body { min-height: 100%; }

body {
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(circle at 12% 8%, rgba(37, 99, 235, .14), transparent 34rem),
    radial-gradient(circle at 88% 90%, rgba(15, 159, 110, .10), transparent 30rem),
    linear-gradient(145deg, var(--bg-a), var(--bg-b));
  font-family: "Microsoft YaHei", "PingFang SC", Arial, sans-serif;
}

body.admin-auth {
  background:
    radial-gradient(circle at 15% 10%, rgba(21, 33, 58, .20), transparent 35rem),
    linear-gradient(145deg, #e9eef7, #f8fafc);
}

button, input { font: inherit; }

.auth-shell {
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 28px 18px;
}

.auth-card {
  width: min(100%, 440px);
  padding: 38px;
  border: 1px solid rgba(207, 217, 232, .9);
  border-radius: 22px;
  background: rgba(255, 255, 255, .94);
  box-shadow: 0 28px 70px rgba(37, 55, 88, .14);
  backdrop-filter: blur(10px);
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 52px;
  height: 52px;
  margin-bottom: 22px;
  border-radius: 15px;
  color: #fff;
  background: linear-gradient(145deg, #3478f6, #1749bd);
  box-shadow: 0 10px 24px rgba(37, 99, 235, .28);
  font-size: 24px;
  font-weight: 900;
}

.brand-mark.admin { background: linear-gradient(145deg, #263a63, #111d34); }

.eyebrow {
  margin: 0 0 7px;
  color: var(--brand);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: .12em;
}

h1 { margin: 0; font-size: 29px; letter-spacing: -.03em; }

.lead {
  margin: 13px 0 24px;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.75;
}

.notice {
  margin-bottom: 20px;
  padding: 12px 14px;
  border: 1px solid;
  border-radius: 10px;
  font-size: 14px;
  line-height: 1.55;
}

.notice.error { color: var(--danger); border-color: #fecdca; background: #fef3f2; }
.notice.success { color: var(--success); border-color: #abefc6; background: #ecfdf3; }

.auth-form { display: grid; }

.auth-form label {
  margin: 0 0 8px;
  color: #344054;
  font-size: 14px;
  font-weight: 700;
}

.auth-form input {
  width: 100%;
  height: 48px;
  margin-bottom: 18px;
  padding: 0 13px;
  border: 1px solid #cbd5e1;
  border-radius: 10px;
  outline: none;
  color: var(--ink);
  background: #fff;
  transition: border-color .15s, box-shadow .15s;
}

.auth-form input:focus {
  border-color: #6d9bff;
  box-shadow: 0 0 0 4px rgba(37, 99, 235, .12);
}

.auth-form button {
  min-height: 49px;
  margin-top: 3px;
  border: 0;
  border-radius: 11px;
  color: #fff;
  background: var(--brand);
  box-shadow: 0 9px 18px rgba(37, 99, 235, .22);
  font-weight: 800;
  cursor: pointer;
  transition: background .15s, transform .15s;
}

.auth-form button:hover { background: var(--brand-dark); transform: translateY(-1px); }
.auth-form button:active { transform: translateY(0); }

.help, .back-link {
  display: block;
  margin: 20px 0 0;
  color: #7a8498;
  font-size: 12px;
  line-height: 1.65;
  text-align: center;
}

.back-link { color: #475d82; text-decoration: none; }
.back-link:hover { color: var(--brand); text-decoration: underline; }

@media (max-width: 520px) {
  .auth-shell { padding: 14px; }
  .auth-card { padding: 28px 22px; border-radius: 18px; }
  h1 { font-size: 26px; }
}