* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", sans-serif;
  background: linear-gradient(135deg, #f5f7fb 0%, #e8edf5 100%);
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
}
.login-card {
  background: #fff;
  padding: 40px 36px 32px;
  border-radius: 12px;
  box-shadow: 0 10px 40px rgba(0,0,0,0.08);
  width: 360px;
}
.login-card h1 {
  margin: 0 0 4px;
  font-size: 22px;
  color: #1a2238;
}
.login-card .subtitle {
  margin: 0 0 28px;
  font-size: 13px;
  color: #8a93a8;
}
.field { margin-bottom: 16px; }
.field label {
  display: block;
  font-size: 13px;
  color: #4a5168;
  margin-bottom: 6px;
}
.field input {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid #d6dae4;
  border-radius: 6px;
  font-size: 14px;
  outline: none;
}
.field input:focus {
  border-color: #4a7fff;
  box-shadow: 0 0 0 3px rgba(74,127,255,0.12);
}
.submit-btn {
  width: 100%;
  padding: 11px;
  background: #1a2238;
  color: #fff;
  border: 0;
  border-radius: 6px;
  font-size: 15px;
  cursor: pointer;
  margin-top: 4px;
}
.submit-btn:hover { background: #2a3450; }
.submit-btn:disabled { background: #8a93a8; cursor: not-allowed; }
.error-msg {
  color: #c63b3b;
  font-size: 13px;
  min-height: 18px;
  margin-top: 12px;
  text-align: center;
}
.hint {
  font-size: 12px;
  color: #aab1c4;
  text-align: center;
  margin-top: 20px;
}