:root {
  color-scheme: light dark;
}

body {
  font-family: system-ui, sans-serif;
  max-width: 900px;
  margin: 2rem auto;
  padding: 0 1rem;
}

.field {
  margin-bottom: 1.5rem;
}

label {
  display: block;
  font-weight: 600;
  margin-bottom: 0.25rem;
}

textarea,
input[type="text"] {
  width: 100%;
  font: inherit;
  padding: 0.5rem;
  box-sizing: border-box;
}

.students-row {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
  align-items: stretch;
}

.students-col {
  flex: 1 1 260px;
  display: flex;
  flex-direction: column;
}

.students-col textarea {
  flex: 1;
}

.email-preview {
  flex: 1;
  border: 1px solid #ccc;
  border-radius: 4px;
  padding: 0.5rem;
  box-sizing: border-box;
  overflow-y: auto;
  font-size: 0.9rem;
  white-space: pre-wrap;
  background: #fafafa;
  color: #000;
}

.hint {
  margin-top: 0.25rem;
  font-size: 0.9rem;
}

.ou-input {
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

.ou-prefix {
  font-weight: 600;
}

.ou-input input {
  flex: 1;
}

button {
  font: inherit;
  padding: 0.6rem 1.2rem;
  cursor: pointer;
}

.error {
  color: #c0392b;
  margin-top: 0.75rem;
}