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

  --c-fmt:    #facc15;
  --c-arg:    #4ade80;
  --c-leak:   #fb923c;
  --c-write:  #ec4899;
  --c-clobber:#ef4444;
  --c-ok:     #22c55e;
  --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: 2.1rem; 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.danger .scenario-header h2::before { content: "\26A0  "; color: var(--c-clobber); }
.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 */
.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; transition: background 0.15s, border-color 0.15s, opacity 0.15s; }
.controls button:hover:not(:disabled) { background: #262b35; border-color: var(--accent); }
.controls button:active:not(:disabled) { transform: translateY(1px); }
.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; }

/* Source code box */
.src {
  background: #0b0d12;
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 12px 14px;
  font-family: var(--mono);
  font-size: 0.9rem;
  margin-bottom: 16px;
  overflow-x: auto;
}
.src pre { margin: 0; white-space: pre-wrap; }
.src .comment { color: var(--muted); }
.src .keyword { color: var(--accent); }
.src .vuln    { color: var(--c-clobber); }
.src .safe    { color: var(--c-ok); }
.src .fmt     { color: var(--c-fmt); }
.src .arg     { color: var(--c-arg); }

/* Format string display */
.format-line {
  font-family: var(--mono);
  font-size: 1rem;
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 14px;
  flex-wrap: wrap;
}
.format-line .label { font-size: 0.75rem; color: var(--muted); text-transform: uppercase; letter-spacing: 0.06em; }
.format-line .fstr { background: #0b0d12; padding: 6px 12px; border: 1px solid var(--border); border-radius: 4px; }
.format-line .fstr .lit { color: var(--text); }
.format-line .fstr .spec { color: var(--c-fmt); font-weight: 700; }
.format-line .fstr .spec.active { background: rgba(250, 204, 21, 0.25); padding: 0 2px; border-radius: 2px; }

/* Stack-style arg list */
.args-box {
  background: #0b0d12;
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 12px;
  margin-bottom: 16px;
}
.args-h {
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--muted);
  font-weight: 700;
  margin-bottom: 8px;
}
.arg-row {
  display: grid;
  grid-template-columns: 110px 1fr 1fr;
  gap: 12px;
  align-items: center;
  font-family: var(--mono);
  font-size: 0.86rem;
  padding: 5px 8px;
  border-radius: 4px;
  margin-bottom: 2px;
  transition: background 0.2s;
}
.arg-row .addr { color: var(--muted); font-size: 0.78rem; }
.arg-row .val  { color: var(--c-arg); font-weight: 600; }
.arg-row .desc { color: var(--muted); font-size: 0.82rem; }
.arg-row.consumed { background: rgba(74, 222, 128, 0.08); }
.arg-row.consumed .desc { color: var(--c-arg); }
.arg-row.active { background: rgba(250, 204, 21, 0.15); border: 1px solid var(--c-fmt); }
.arg-row.controlled { background: rgba(236, 72, 153, 0.15); }
.arg-row.controlled .val { color: var(--c-write); }

/* Output box */
.output-box {
  background: #050709;
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 12px 14px;
  font-family: var(--mono);
  font-size: 0.95rem;
  min-height: 50px;
}
.output-h {
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--muted);
  font-weight: 700;
  margin-bottom: 6px;
}
.output-text { color: var(--c-leak); white-space: pre-wrap; word-break: break-all; }
.output-text .empty { color: var(--muted); font-style: italic; }

/* Memory area showing where %s dereferences to */
.mem-deref {
  background: #0b0d12;
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 12px;
  margin-bottom: 16px;
}
.mem-deref-row {
  display: grid;
  grid-template-columns: 130px 1fr;
  gap: 14px;
  font-family: var(--mono);
  font-size: 0.85rem;
}
.mem-deref-row .addr { color: var(--muted); }
.mem-deref-row .content { color: var(--c-leak); }

/* Variant for write target */
.write-target {
  background: rgba(236, 72, 153, 0.08);
  border: 1px solid rgba(236, 72, 153, 0.4);
  border-radius: 6px;
  padding: 12px 14px;
  font-family: var(--mono);
  font-size: 0.85rem;
  margin-top: 8px;
}
.write-target .label {
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--c-write);
  font-weight: 700;
  margin-bottom: 6px;
}
.write-target .target-addr { color: var(--c-write); font-weight: 700; }
.write-target .before { color: var(--muted); text-decoration: line-through; }
.write-target .after  { color: var(--c-write); font-weight: 700; }

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); }