.b64-wrap {
  max-width: 960px;
  margin: 0 auto;
  padding: 0 1rem 3rem;
}

.b64-tabs {
  display: flex;
  gap: 4px;
  margin-bottom: 1.25rem;
  border-bottom: 1px solid var(--border, #e5e7eb);
  padding-bottom: 0;
}

.b64-tab {
  padding: 6px 18px;
  font-size: .8125rem;
  font-weight: 600;
  border: none;
  background: none;
  color: var(--muted, #6b7280);
  cursor: pointer;
  border-bottom: 2px solid transparent;
  margin-bottom: -1px;
  transition: color .12s, border-color .12s;
}
.b64-tab:hover { color: #1e293b; }
.b64-tab.active { color: #2563eb; border-bottom-color: #2563eb; }

.b64-pane { }
.b64-pane.hidden { display: none; }

.b64-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.25rem;
}

.b64-col {
  display: flex;
  flex-direction: column;
  gap: .5rem;
}

.b64-label {
  font-size: .75rem;
  font-weight: 700;
  letter-spacing: .06em;
  text-transform: uppercase;
  color: var(--muted, #6b7280);
}

.b64-textarea {
  width: 100%;
  min-height: 180px;
  padding: .65rem .75rem;
  font-family: ui-monospace, monospace;
  font-size: .8125rem;
  border: 1px solid var(--border, #e5e7eb);
  border-radius: 6px;
  background: var(--input-bg, #f9fafb);
  color: var(--text, #111);
  resize: vertical;
  box-sizing: border-box;
  line-height: 1.6;
}
.b64-textarea:focus { outline: 2px solid #2563eb; border-color: transparent; }
.b64-textarea--tall { min-height: 220px; }

.b64-actions {
  display: flex;
  gap: .5rem;
  flex-wrap: wrap;
}

.b64-status {
  margin-top: .75rem;
  font-size: .8rem;
  color: var(--muted, #6b7280);
  min-height: 1.2em;
}

/* File drop zone */
.b64-drop-zone {
  border: 2px dashed var(--border, #e5e7eb);
  border-radius: 10px;
  padding: 3rem 2rem;
  text-align: center;
  cursor: pointer;
  transition: border-color .15s, background .15s;
  background: var(--input-bg, #f9fafb);
}
.b64-drop-zone:hover,
.b64-drop-zone.drag-over {
  border-color: #2563eb;
  background: #eff6ff;
}
.b64-drop-icon { font-size: 2.5rem; margin-bottom: .75rem; }
.b64-drop-zone p { font-size: .875rem; color: var(--muted, #6b7280); margin: 0; }

.b64-file-info {
  font-size: .8125rem;
  color: var(--muted, #6b7280);
  margin-bottom: .5rem;
  font-family: ui-monospace, monospace;
}

.b64-file-result {
  margin-top: 1.25rem;
  display: flex;
  flex-direction: column;
  gap: .5rem;
}
.b64-file-result.hidden { display: none; }

@media (max-width: 640px) {
  .b64-row { grid-template-columns: 1fr; }
}