/* ── Visualizer ── */
.algo-sel { display: flex; gap: 6px; flex-wrap: wrap; margin-bottom: 18px; }

/* ── Diffusion Coding Lab ── */
.diff-ex-page { padding: 0; display: flex; flex-direction: column; height: 100%; }
.diff-ex-header {
  padding: 12px 18px; background: var(--surf);
  border-bottom: 1px solid var(--bdr);
  display: flex; align-items: flex-start; justify-content: space-between;
  gap: 12px; flex-wrap: wrap;
}
.diff-ex-title { font-size: 14px; font-weight: 600; margin-bottom: 3px; }
.diff-ex-meta { font-size: 11px; color: var(--mut); }
.diff-ex-body { display: flex; flex: 1; min-height: 0; flex-wrap: wrap; }
.diff-ex-left { flex: 1; min-width: 300px; display: flex; flex-direction: column; border-right: 1px solid var(--bdr); }
.diff-ex-right { width: 320px; min-width: 260px; display: flex; flex-direction: column; }

.step-tabs { display: flex; border-bottom: 1px solid var(--bdr); overflow-x: auto; }
.step-tab {
  padding: 9px 14px; font-size: 12px; color: var(--mut);
  cursor: pointer; border-bottom: 2px solid transparent;
  font-family: var(--mono); white-space: nowrap; flex-shrink: 0;
}
.step-tab.active { color: var(--acc); border-color: var(--acc); }
.step-tab.done { color: var(--acc3); }

.code-area {
  flex: 1; background: var(--cbg); font-family: var(--mono);
  font-size: 12px; color: var(--txt); border: none; outline: none;
  padding: 16px; resize: none; line-height: 1.7; tab-size: 2; min-height: 220px;
}
.run-bar {
  padding: 9px 16px; background: var(--surf);
  border-top: 1px solid var(--bdr);
  display: flex; align-items: center; gap: 9px;
}
.run-btn { padding: 6px 16px; border-radius: 6px; background: var(--acc3); border: none; color: #000; font-weight: 700; font-size: 12px; cursor: pointer; font-family: var(--mono); }
.hint-btn { padding: 6px 12px; border-radius: 6px; background: transparent; border: 1px solid var(--bdr); color: var(--mut); font-size: 11px; cursor: pointer; font-family: var(--mono); }

.ptabs { display: flex; border-bottom: 1px solid var(--bdr); }
.ptab { padding: 8px 12px; font-size: 11px; color: var(--mut); cursor: pointer; border-bottom: 2px solid transparent; font-family: var(--mono); }
.ptab.active { color: var(--acc); border-color: var(--acc); }
.pbody { flex: 1; overflow-y: auto; padding: 12px; }

.ol { font-family: var(--mono); font-size: 11px; line-height: 1.8; color: var(--acc3); }
.oe { color: #ff6b9d; font-family: var(--mono); font-size: 11px; line-height: 1.8; }
.oi { color: var(--mut); font-family: var(--mono); font-size: 11px; }

.hbox { background: var(--surf2); border: 1px solid var(--bdr); border-radius: 7px; padding: 10px; margin-bottom: 7px; font-size: 12px; line-height: 1.6; }
.hlv { font-size: 9px; font-family: var(--mono); color: var(--acc); margin-bottom: 3px; font-weight: 700; }

.mini-vis { display: flex; gap: 8px; flex-wrap: wrap; padding: 12px; background: var(--surf); border-top: 1px solid var(--bdr); align-items: flex-start; }
.mv-item { display: flex; flex-direction: column; align-items: center; gap: 4px; }
.mv-lbl { font-size: 9px; color: var(--mut); font-family: var(--mono); text-align: center; }
.mv-canvas { border-radius: 5px; border: 1px solid var(--bdr); image-rendering: pixelated; display: block; }