* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: Arial, Helvetica, sans-serif;
  background: #111827;
  color: #e5e7eb;
}
.page {
  max-width: 1180px;
  margin: 0 auto;
  padding: 28px;
}
h1 { margin: 0 0 22px; font-size: 28px; }
.tabs {
  display: flex;
  gap: 8px;
  margin-bottom: 18px;
  flex-wrap: wrap;
}
.tab, .generate, #copy-btn {
  border: 1px solid #374151;
  background: #1f2937;
  color: #e5e7eb;
  padding: 10px 14px;
  cursor: pointer;
  border-radius: 8px;
  font-size: 14px;
}
.tab.active { background: #374151; border-color: #6b7280; }
.panel {
  display: none;
  padding: 18px;
  background: #172033;
  border: 1px solid #263244;
  border-radius: 10px;
  margin-bottom: 16px;
}
.panel.active { display: block; }
.grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(180px, 1fr));
  gap: 14px;
  margin-bottom: 16px;
}
.grid.single { grid-template-columns: minmax(180px, 320px); }
label {
  display: flex;
  flex-direction: column;
  gap: 7px;
  font-size: 14px;
  color: #cbd5e1;
}
input {
  width: 100%;
  border: 1px solid #374151;
  background: #0b1220;
  color: #e5e7eb;
  border-radius: 8px;
  padding: 10px 12px;
  font-size: 15px;
}
input:focus, textarea:focus {
  outline: 2px solid #4b5563;
}
.generate { background: #243044; }
.output-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  margin-top: 10px;
}
h2 { margin: 8px 0; font-size: 18px; }
textarea {
  width: 100%;
  min-height: 460px;
  resize: vertical;
  border: 1px solid #374151;
  background: #030712;
  color: #e5e7eb;
  border-radius: 10px;
  padding: 16px;
  font-family: "DejaVu Sans Mono", Consolas, monospace;
  font-size: 14px;
  line-height: 1.45;
}
.error {
  color: #fecaca;
  min-height: 22px;
  margin: 6px 0 8px;
}
@media (max-width: 760px) {
  .grid { grid-template-columns: 1fr; }
  .page { padding: 18px; }
}