:root {
  --bg:        #0f1115;
  --surface:   #181b22;
  --surface-2: #1f242d;
  --border:    #2a2e38;
  --text:      #e6e8ee;
  --muted:     #8a93a6;
  --accent:    #6ea8ff;

  --c-static:  #4ade80;
  --c-heap:    #fb923c;
  --c-stale:   #f87171;
  --c-arrow:   #facc15;
  --c-warn:    #f59e0b;

  --mono: ui-monospace, "Cascadia Mono", "JetBrains Mono", Menlo, Consolas, monospace;
}
* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; background: var(--bg); color: var(--text); font-family: -apple-system, system-ui, "Segoe UI", Roboto, Helvetica, Arial, sans-serif; line-height: 1.55; }
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
code { font-family: var(--mono); background: var(--surface-2); padding: 1px 6px; border-radius: 4px; font-size: 0.9em; }
em { color: var(--accent); font-style: normal; }

.hero { border-bottom: 1px solid var(--border); background: linear-gradient(180deg, #11141b 0%, var(--bg) 100%); }
.hero-inner { max-width: 1100px; margin: 0 auto; padding: 48px 32px 32px; }
.hero h1 { font-size: 2rem; margin: 0 0 12px; }
.lede { font-size: 1rem; color: var(--muted); max-width: 820px; }
.toc { margin-top: 22px; display: flex; flex-wrap: wrap; gap: 10px; font-family: var(--mono); font-size: 0.85rem; }
.toc a { background: var(--surface); padding: 5px 11px; border-radius: 5px; border: 1px solid var(--border); }

.scenario { max-width: 1100px; margin: 0 auto; padding: 44px 32px; border-bottom: 1px solid var(--border); }
.scenario-header h2 { margin: 0 0 10px; font-size: 1.45rem; }
.scenario-header p { color: var(--muted); max-width: 820px; margin: 0; }
.scenario-body { margin-top: 24px; }

.viz { background: var(--surface); border: 1px solid var(--border); border-radius: 10px; padding: 20px 22px; min-height: 280px; }

.controls { display: flex; gap: 8px; align-items: center; margin-top: 14px; }
.controls button { background: var(--surface-2); border: 1px solid var(--border); color: var(--text); font-family: var(--mono); font-size: 1rem; padding: 6px 12px; border-radius: 6px; cursor: pointer; }
.controls button:hover:not(:disabled) { background: #262b35; border-color: var(--accent); }
.controls button:disabled { opacity: 0.35; cursor: not-allowed; }
.step-indicator { margin-left: auto; color: var(--muted); font-family: var(--mono); font-size: 0.85rem; }
.step-status { margin-top: 14px; font-size: 0.92rem; padding: 10px 14px; background: var(--surface-2); border-left: 3px solid var(--accent); border-radius: 4px; min-height: 60px; }

/* Memory blocks */
.mem-block {
  background: #0b0d12;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 14px;
  margin-bottom: 14px;
  font-family: var(--mono);
}
.mem-block.b-static { border-left: 4px solid var(--c-static); }
.mem-block.b-heap   { border-left: 4px solid var(--c-heap); }
.mem-block.b-stale  { border-left: 4px solid var(--c-stale); opacity: 0.6; }

.mem-block-h {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  font-weight: 700;
  margin-bottom: 8px;
}
.mem-block.b-static .mem-block-h { color: var(--c-static); }
.mem-block.b-heap   .mem-block-h { color: var(--c-heap); }
.mem-block.b-stale  .mem-block-h { color: var(--c-stale); }

.mem-block-sub { font-size: 0.78rem; color: var(--muted); margin-bottom: 8px; font-family: -apple-system, system-ui, sans-serif; }

.mem-cell {
  display: grid;
  grid-template-columns: 200px 1fr 1fr;
  gap: 12px;
  align-items: center;
  padding: 6px 8px;
  border-radius: 4px;
  font-family: var(--mono);
  font-size: 0.86rem;
}
.mem-cell:nth-child(even) { background: rgba(255,255,255,0.02); }
.mem-cell .addr { color: var(--muted); font-size: 0.82rem; }
.mem-cell .addr.s { color: var(--c-static); font-weight: 600; }
.mem-cell .addr.h { color: var(--c-heap); font-weight: 600; }
.mem-cell .addr.x { color: var(--c-stale); text-decoration: line-through; }
.mem-cell .name { color: var(--text); }
.mem-cell .val  { color: var(--c-arrow); font-weight: 600; }
.mem-cell .val.ptr { color: var(--c-heap); }
.mem-cell .val.ptr.bad { color: var(--c-stale); text-decoration: line-through; }
.mem-cell .val.stat { color: var(--c-static); }

/* Flow indicator between memory blocks */
.flow-arrow {
  text-align: center;
  font-family: var(--mono);
  color: var(--c-arrow);
  font-size: 1.3rem;
  padding: 4px 0;
}
.flow-arrow .label {
  display: inline-block;
  background: var(--surface);
  padding: 2px 10px;
  border-radius: 12px;
  border: 1px solid var(--border);
  font-size: 0.78rem;
  font-family: -apple-system, system-ui, sans-serif;
  color: var(--muted);
  vertical-align: middle;
  margin-left: 6px;
}

/* Pointer chain notation */
.chain-notation {
  background: rgba(110, 168, 255, 0.08);
  border: 1px solid var(--accent);
  border-radius: 6px;
  padding: 12px 14px;
  font-family: var(--mono);
  font-size: 0.92rem;
  text-align: center;
  margin: 14px 0;
}
.chain-notation .lit { color: var(--c-static); font-weight: 700; }
.chain-notation .deref-l, .chain-notation .deref-r { color: var(--c-arrow); }
.chain-notation .offset { color: var(--c-heap); }

/* CE-style intro text */
.intro-block {
  font-family: -apple-system, system-ui, sans-serif;
  font-size: 0.95rem;
  line-height: 1.6;
  color: var(--text);
  padding: 14px 16px;
  background: #0b0d12;
  border: 1px solid var(--border);
  border-radius: 8px;
}
.intro-block p { margin: 0 0 12px; }
.intro-block p:last-child { margin-bottom: 0; }
.intro-block strong { color: var(--accent); }
.intro-block ul { margin: 6px 0 0; padding-left: 22px; color: var(--muted); }
.intro-block ul li { margin-bottom: 4px; }
.intro-block .static-color { color: var(--c-static); font-weight: 600; }
.intro-block .heap-color   { color: var(--c-heap);   font-weight: 600; }

footer { text-align: center; padding: 30px 20px 60px; color: var(--muted); font-size: 0.85rem; border-top: 1px solid var(--border); margin-top: 20px; }
footer p { max-width: 820px; margin: 0 auto 10px; }
footer .back-link { font-family: var(--mono); }