body {
  font-family: 'Segoe UI', Arial, sans-serif;
  background: #f6f8fa;
  margin: 0;
}
.mainbox {
  max-width: 700px;
  margin: 56px auto;
  background: #fff;
  border-radius: 22px;
  box-shadow: 0 6px 22px #e0e8f0;
  padding: 2.5em 3em 1.8em 3em;
}
h2 {
  color: #1d3557;
  margin-bottom: 1.2em;
}
.form-group {
  margin-bottom: 1.1em;
}
label {
  display: block;
  font-weight: 500;
  margin-bottom: 0.3em;
}
input, select {
  width: 100%;
  padding: .7em;
  border-radius: 8px;
  border: 1px solid #ccd;
  font-size: 1.1em;
}
button {
  width: 100%;
  padding: 1em;
  background: #457b9d;
  color: #fff;
  font-size: 1.16em;
  border: none;
  border-radius: 8px;
  margin-top: 1.2em;
  font-weight: bold;
  cursor: pointer;
  box-shadow: 0 2px 6px #e0e8f0;
}
button:hover { background: #1d3557; }
.msg-error {
  background: #ffd9d9;
  color: #d00000;
  padding: .95em;
  border-radius: 7px;
  margin-bottom: 1em;
}
@media(max-width:850px) {
  .mainbox { max-width:98vw; padding: 1.1em; }
}