:root {
  color-scheme: light dark;
  font-family: Arial, Helvetica, sans-serif;
}

body {
  margin: 0;
  background: #f5f7fb;
  color: #172033;
}

main {
  max-width: 980px;
  margin: 0 auto;
  padding: 32px 16px;
}

.panel {
  background: white;
  border: 1px solid #dbe2ee;
  border-radius: 8px;
  padding: 24px;
}

.hidden {
  display: none;
}

header {
  align-items: center;
  display: flex;
  gap: 16px;
  justify-content: space-between;
  margin-bottom: 24px;
}

h1 {
  font-size: 28px;
  margin: 0 0 8px;
}

p {
  line-height: 1.45;
}

label {
  display: block;
  font-weight: 700;
  margin-bottom: 8px;
}

.row,
.actions {
  display: flex;
  gap: 8px;
}

input {
  border: 1px solid #bcc7d8;
  border-radius: 6px;
  flex: 1;
  font-size: 16px;
  padding: 10px 12px;
}

button {
  background: #1f6feb;
  border: 0;
  border-radius: 6px;
  color: white;
  cursor: pointer;
  font-size: 15px;
  padding: 10px 14px;
}

button:hover {
  background: #1b5fc8;
}

.error {
  color: #b42318;
  min-height: 20px;
}

#message-count {
  color: #5c6b82;
  margin: 0;
}

.message {
  border-top: 1px solid #dbe2ee;
  padding: 16px 0;
}

.message-title {
  font-weight: 700;
  margin-bottom: 8px;
}

.message p {
  margin: 0 0 12px;
  white-space: pre-wrap;
}

dl {
  display: grid;
  gap: 4px 12px;
  grid-template-columns: 140px 1fr;
  margin: 0;
}

dt {
  color: #5c6b82;
}

dd {
  margin: 0;
}

@media (max-width: 640px) {
  header,
  .row,
  .actions {
    align-items: stretch;
    flex-direction: column;
  }

  dl {
    grid-template-columns: 1fr;
  }
}