:root {
  --bg: #eef2ff;
  --surface: #ffffff;
  --border: #dbe3f0;
  --text: #1a2233;
  --text-muted: #64748b;
  --primary: #2563eb;
  --primary-hover: #1d4ed8;
  --error: #dc2626;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC",
    "Microsoft YaHei", sans-serif;
  background: linear-gradient(135deg, #eef2ff 0%, #f8fafc 50%, #ecfeff 100%);
  color: var(--text);
}

.login-page {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
}

.login-card {
  width: 100%;
  max-width: 400px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 32px 28px;
  box-shadow: 0 12px 40px rgba(15, 23, 42, 0.08);
}

.login-brand h1 {
  margin: 0 0 6px;
  font-size: 1.5rem;
}

.login-brand p {
  margin: 0 0 24px;
  color: var(--text-muted);
  font-size: 0.92rem;
}

.field {
  display: block;
  margin-bottom: 16px;
}

.field span {
  display: block;
  margin-bottom: 6px;
  font-size: 0.875rem;
  color: var(--text-muted);
}

.field input {
  width: 100%;
  height: 42px;
  padding: 0 12px;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 0.95rem;
}

.field input:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.12);
}

.error {
  margin: 0 0 12px;
  color: var(--error);
  font-size: 0.875rem;
}

.btn-login {
  width: 100%;
  height: 42px;
  border: none;
  border-radius: 8px;
  background: var(--primary);
  color: #fff;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
}

.btn-login:hover { background: var(--primary-hover); }
.btn-login:disabled { opacity: 0.65; cursor: not-allowed; }