/* ===== Reset & variabile ===== */
* { margin: 0; padding: 0; box-sizing: border-box; }

:root {
  --bg:       #0a0a0a;
  --surface:  #161616;
  --surface-2:#1f1f1f;
  --border:   #2a2a2a;
  --border-2: #3a3a3a;
  --text:     #f0f0f0;
  --muted:    #999999;
  --faint:    #666666;
  --red:      #e63946;
  --red-d:    #c1121f;
  --red-l:    #ff5a6b;
  --amber:    #f4a261;
  --gold:     #e9c46a;
  --serif:    Georgia, "Times New Roman", serif;
  --mono:     Consolas, "Courier New", monospace;
}

html { scroll-behavior: smooth; }
body {
  font-family: var(--serif);
  color: var(--text);
  background: var(--bg);
  line-height: 1.65;
  font-size: 16px;
}

.container {
  max-width: 1000px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

.r { color: var(--red); }

/* ===== Header ===== */
.top {
  position: sticky;
  top: 0;
  background: rgba(10, 10, 10, 0.94);
  backdrop-filter: blur(10px);
  border-bottom: 2px solid var(--red);
  z-index: 50;
}
.nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.9rem 1.5rem;
  flex-wrap: wrap;
  gap: 0.5rem;
}
.logo {
  font-weight: bold;
  font-size: 1.25rem;
  letter-spacing: -0.01em;
}
nav a {
  color: var(--muted);
  text-decoration: none;
  margin-left: 1.1rem;
  font-size: 0.92rem;
  transition: color 0.2s;
}
nav a:hover { color: var(--red); }
nav a:first-child { margin-left: 0; }

/* ===== Generale ===== */
section {
  padding: 3.5rem 0;
  border-bottom: 1px solid var(--border);
  scroll-margin-top: 70px;
}
section:last-of-type { border-bottom: none; }

h1 {
  font-size: 2.8rem;
  font-weight: normal;
  line-height: 1.1;
  margin: 1rem 0 1.5rem;
}
h2 {
  font-size: 1.9rem;
  font-weight: normal;
  margin-bottom: 0.4rem;
  border-bottom: 3px solid var(--red);
  padding-bottom: 0.4rem;
  display: inline-block;
}
h3 {
  font-size: 1.2rem;
  font-weight: bold;
  margin-bottom: 0.6rem;
  color: var(--red);
}
h4 {
  font-size: 1.05rem;
  font-weight: bold;
  margin-bottom: 0.5rem;
}

.eyebrow {
  font-family: var(--mono);
  text-transform: uppercase;
  letter-spacing: 0.18em;
  font-size: 0.75rem;
  color: var(--red);
}
.lead {
  font-size: 1.1rem;
  color: var(--muted);
  max-width: 680px;
  margin-bottom: 2rem;
}
.sub {
  color: var(--muted);
  margin: 1rem 0 2rem;
  max-width: 760px;
}

p { margin-bottom: 0.8rem; color: var(--text); }
ul, ol { margin: 0.5rem 0 0.8rem 1.5rem; color: var(--text); }
ul li, ol li { padding: 0.2rem 0; }

/* ===== Hero card cu nume ===== */
.card-info {
  border: 2px solid var(--red);
  background: var(--surface);
  padding: 1.2rem 1.5rem;
  max-width: 620px;
}
.row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.6rem 0;
  border-bottom: 1px dashed var(--border);
}
.row:last-child { border-bottom: none; }
.k {
  font-size: 0.85rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}
.v {
  font-weight: bold;
  color: var(--red);
}

/* ===== Blocuri de teorie ===== */
.block {
  border: 1px solid var(--border);
  background: var(--surface);
  padding: 1.3rem 1.5rem;
  margin-bottom: 1.1rem;
  border-left: 3px solid var(--red);
}
.block h3 {
  margin-bottom: 0.7rem;
}
.block p {
  font-size: 0.97rem;
  color: var(--text);
}
.block ul, .block ol {
  font-size: 0.96rem;
  color: var(--text);
}
.block .nota {
  margin-top: 0.7rem;
  padding: 0.6rem 0.9rem;
  background: var(--bg);
  border-left: 2px solid var(--red);
  font-size: 0.92rem;
  color: var(--muted);
}
.block .nota strong { color: var(--red); }

/* ===== Tabel ===== */
.tbl {
  width: 100%;
  border-collapse: collapse;
  margin: 0.8rem 0;
  font-size: 0.92rem;
}
.tbl th, .tbl td {
  border: 1px solid var(--border-2);
  padding: 0.5rem 0.8rem;
  text-align: left;
}
.tbl th {
  background: var(--bg);
  color: var(--red);
  font-weight: bold;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  font-size: 0.8rem;
}
.tbl td code {
  font-family: var(--mono);
  color: var(--red-l);
  font-size: 0.92rem;
}

/* ===== Cod ===== */
.code {
  background: #000000;
  color: #e8e8e8;
  padding: 0.9rem 1rem;
  font-family: var(--mono);
  font-size: 0.85rem;
  line-height: 1.55;
  overflow-x: auto;
  margin: 0.8rem 0;
  border: 1px solid var(--border);
  border-left: 3px solid var(--red);
  white-space: pre;
}
.code .kw { color: var(--red-l); font-weight: bold; }
.code .num { color: #ffd166; }
.code .str { color: #95d5b2; }
.code .cm { color: var(--faint); font-style: italic; }
.code .ty { color: #8ecae6; }

/* cod inline */
p code, li code, .block code {
  font-family: var(--mono);
  background: var(--bg);
  padding: 0.05rem 0.4rem;
  border: 1px solid var(--border);
  color: var(--red-l);
  font-size: 0.88em;
  border-radius: 2px;
}

/* etichetă tip */
.tag {
  display: inline-block;
  font-family: var(--mono);
  font-size: 0.7rem;
  color: var(--red);
  letter-spacing: 0.15em;
  text-transform: uppercase;
  margin-bottom: 0.3rem;
}

/* ===== Sortari: grid 2 coloane ===== */
.sort-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
}

/* ===== Constructor de exercitii ===== */
.constructor-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.1rem;
  margin-bottom: 1.2rem;
}
.constructor-col h3 {
  display: flex;
  align-items: baseline;
  gap: 0.6rem;
}
.constructor-col h3 .count {
  font-family: var(--mono);
  font-size: 0.7rem;
  letter-spacing: 0.12em;
  color: var(--muted);
  font-weight: normal;
}
.field-list {
  display: flex;
  flex-direction: column;
  gap: 0.55rem;
  margin: 0.8rem 0 0.9rem;
}
.field-row {
  display: flex;
  align-items: stretch;
  border: 1px solid var(--border);
  background: var(--bg);
  transition: border-color 0.15s;
}
.field-row:focus-within {
  border-color: var(--red);
}
.field-num {
  display: flex;
  align-items: center;
  justify-content: center;
  min-width: 52px;
  padding: 0 0.6rem;
  font-family: var(--mono);
  font-size: 0.95rem;
  font-weight: bold;
  color: var(--red);
  background: var(--surface);
  border-right: 1px solid var(--border);
  letter-spacing: 0.04em;
}
.field-row.required .field-num::after {
  content: "*";
  color: var(--muted);
  margin-left: 0.15rem;
  font-weight: normal;
  font-size: 0.8rem;
}
.field-input {
  flex: 1;
  background: transparent;
  color: var(--text);
  border: none;
  outline: none;
  resize: vertical;
  font-family: var(--serif);
  font-size: 0.96rem;
  line-height: 1.5;
  padding: 0.65rem 0.85rem;
  min-height: 2.5rem;
  max-height: 14rem;
}
.field-input::placeholder { color: var(--faint); font-style: italic; }
.field-remove {
  background: transparent;
  border: none;
  border-left: 1px solid var(--border);
  color: var(--faint);
  cursor: pointer;
  padding: 0 0.95rem;
  font-family: var(--mono);
  font-size: 1.05rem;
  transition: color 0.15s, background 0.15s;
}
.field-remove:hover { color: var(--red); background: var(--surface-2); }
.field-row.required .field-remove {
  color: var(--faint);
  cursor: not-allowed;
  opacity: 0.35;
  pointer-events: none;
}
.btn-add {
  display: block;
  width: 100%;
  background: transparent;
  border: 1px dashed var(--border-2);
  color: var(--muted);
  padding: 0.6rem 1rem;
  font-family: var(--mono);
  font-size: 0.85rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  cursor: pointer;
  transition: all 0.15s;
}
.btn-add:hover {
  border-color: var(--red);
  color: var(--red);
  background: var(--surface);
}
.constructor-actions {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 0.8rem;
  flex-wrap: wrap;
  margin-top: 0.4rem;
}
.constructor-meta {
  font-family: var(--mono);
  font-size: 0.78rem;
  letter-spacing: 0.06em;
  color: var(--muted);
}
.btn-ghost {
  background: transparent;
  border: 1px solid var(--border-2);
  color: var(--muted);
  padding: 0.5rem 1.1rem;
  cursor: pointer;
  font-family: var(--serif);
  font-size: 0.92rem;
  transition: all 0.15s;
}
.btn-ghost:hover { border-color: var(--red); color: var(--red); }

/* Preview output */
#constructor-output {
  margin-top: 1.4rem;
  border: 2px solid var(--red);
  background: var(--surface);
  padding: 1.3rem 1.5rem;
}
#constructor-output .out-head {
  font-family: var(--mono);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.18em;
  color: var(--red);
  margin-bottom: 0.4rem;
}
#constructor-output h4 {
  font-family: var(--mono);
  font-size: 0.8rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--red);
  margin: 1rem 0 0.5rem;
  border-bottom: 1px dashed var(--border);
  padding-bottom: 0.3rem;
}
#constructor-output h4:first-of-type { margin-top: 0.3rem; }
#constructor-output ol {
  margin-left: 1.6rem;
  color: var(--text);
  font-size: 0.97rem;
  line-height: 1.55;
}
#constructor-output ol li {
  padding: 0.25rem 0;
  white-space: pre-wrap;
}
#constructor-output .empty {
  color: var(--faint);
  font-style: italic;
  font-size: 0.92rem;
  padding: 0.3rem 0;
}

/* ----- Constructor: wrappers & erori per câmp ----- */
.field-wrap { display: flex; flex-direction: column; }
.field-input-single {
  resize: none;
  min-height: 2.4rem;
  max-height: 2.4rem;
}
.field-error {
  font-family: var(--mono);
  font-size: 0.75rem;
  color: var(--red);
  padding: 0.25rem 0.6rem;
  background: rgba(230, 57, 70, 0.07);
  border-left: 2px solid var(--red);
  margin-top: 2px;
}

/* ----- Help toggle & panel ----- */
.btn-help-inline {
  background: transparent;
  border: none;
  color: var(--red);
  font-family: var(--mono);
  font-size: 0.82rem;
  cursor: pointer;
  padding: 0;
  text-decoration: underline;
  letter-spacing: 0.04em;
}
.btn-help-inline:hover { color: var(--red-l); }
.constructor-help {
  margin: 0.6rem 0 1rem;
  padding: 1rem 1.2rem;
  background: var(--bg);
  border-left: 3px solid var(--red);
  font-size: 0.95rem;
}
.constructor-help h4 {
  color: var(--red);
  font-family: var(--mono);
  text-transform: uppercase;
  font-size: 0.8rem;
  letter-spacing: 0.12em;
  margin: 0.9rem 0 0.4rem;
}
.constructor-help h4:first-child { margin-top: 0; }
.constructor-help .tbl { margin: 0.4rem 0 0.6rem; }
.constructor-help .help-note {
  font-size: 0.88rem;
  color: var(--muted);
  font-style: italic;
  margin-top: 0.4rem;
}

/* ----- Parametri (p, k, show-all) ----- */
.constructor-params {
  display: flex;
  flex-wrap: wrap;
  gap: 1.2rem;
  align-items: end;
  padding: 0.8rem 1rem;
  background: var(--bg);
  border: 1px dashed var(--border-2);
  margin-bottom: 0.8rem;
}
.cp-label {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
  font-family: var(--mono);
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--muted);
}
.cp-input {
  width: 220px;
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text);
  font-family: var(--serif);
  font-size: 0.95rem;
  padding: 0.45rem 0.65rem;
  outline: none;
}
.cp-input:focus { border-color: var(--red); }
.cp-label-wide { flex: 1 1 100%; }
.cp-label-wide .cp-input { width: 100%; }
#out-find { margin-top: 1.2rem; padding-top: 0.8rem; border-top: 1px dashed var(--border-2); }
.cp-check {
  display: flex;
  align-items: center;
  gap: 0.45rem;
  font-family: var(--mono);
  font-size: 0.78rem;
  letter-spacing: 0.05em;
  color: var(--muted);
  cursor: pointer;
}
.cp-check input { accent-color: var(--red); }
.constructor-buttons { display: inline-flex; gap: 0.5rem; }

/* ----- Condiții comutabile ----- */
.constructor-conditions {
  padding: 0.8rem 1rem;
  background: var(--bg);
  border: 1px dashed var(--border-2);
  margin-bottom: 0.8rem;
}
.constructor-conditions h4 {
  margin: 0 0 0.7rem;
  font-family: var(--mono);
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text);
}
.constructor-conditions h4 .cond-hint {
  text-transform: none;
  letter-spacing: 0;
  font-size: 0.72rem;
  color: var(--muted);
  font-weight: normal;
}
.cond-line { margin-bottom: 0.6rem; }
.cond-line:last-child { margin-bottom: 0; }
.cond-inline {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.5rem;
  font-family: var(--mono);
  font-size: 0.78rem;
  color: var(--muted);
}
.cond-line code {
  font-family: var(--mono);
  background: var(--surface);
  border: 1px solid var(--border);
  padding: 0 0.3em;
}
.cond-select {
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text);
  font-family: var(--serif);
  font-size: 0.9rem;
  padding: 0.3rem 0.5rem;
  outline: none;
}
.cond-select:focus { border-color: var(--red); }
.cond-num {
  width: 56px;
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text);
  font-family: var(--serif);
  font-size: 0.9rem;
  padding: 0.3rem 0.4rem;
  outline: none;
}
.cond-num:focus { border-color: var(--red); }
.cp-label-inline { flex-direction: row; align-items: center; gap: 0.5rem; }
.cond-step-echo { color: var(--red); font-weight: bold; }
.cond-hint-inline { color: var(--muted); font-size: 0.72rem; }

/* sub-opțiuni dezvăluite sub „Consecutive?” */
.cond-suboptions {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.7rem;
  margin-left: 1.4rem;
  padding: 0.5rem 0.7rem;
  border-left: 2px solid var(--red);
  background: var(--surface);
  font-family: var(--mono);
  font-size: 0.78rem;
  color: var(--muted);
}
.cond-sub-label em { color: var(--muted); font-style: italic; }
.cp-radio {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  cursor: pointer;
  color: var(--text);
}
.cp-radio input { accent-color: var(--red); }

/* ----- Output: summary, vars, rules ----- */
.out-summary {
  font-family: var(--mono);
  font-size: 0.85rem;
  padding: 0.6rem 0.8rem;
  background: var(--bg);
  border-left: 2px solid var(--red);
  margin-bottom: 0.8rem;
  color: var(--text);
  line-height: 1.5;
}
.out-summary strong { color: var(--red); }
.out-summary .warn { color: #ffd166; }

.out-vars {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-bottom: 0.6rem;
}
.var-chip {
  font-family: var(--mono);
  font-size: 0.85rem;
  background: var(--bg);
  border: 1px solid var(--border);
  border-left: 2px solid var(--red);
  padding: 0.3rem 0.6rem;
  color: var(--text);
}
.var-chip strong { color: var(--red); font-weight: bold; margin-right: 0.2rem; }

.out-rules code {
  font-family: var(--mono);
  background: var(--bg);
  padding: 0.05rem 0.4rem;
  border: 1px solid var(--border);
  color: var(--red-l);
  font-size: 0.88em;
  border-radius: 2px;
}

/* ----- Soluții ----- */
.sol-head {
  color: var(--text);
  margin-top: 0.2rem;
  margin-bottom: 0.5rem;
}
.meta-note {
  font-size: 0.8rem;
  color: var(--muted);
  font-family: var(--mono);
}
.sol-list {
  font-family: var(--mono);
  font-size: 0.9rem;
  margin-left: 1.8rem;
  color: var(--text);
}
.sol-list li { padding: 0.25rem 0; }
.sol-cell-inline {
  display: inline-block;
  padding: 0.05rem 0.4rem;
  background: var(--surface-2);
  border-left: 2px solid var(--red);
  margin-right: 0.25rem;
}
.solution-display {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  margin: 0.4rem 0;
}
.sol-cell {
  font-family: var(--mono);
  font-weight: bold;
  background: var(--surface-2);
  border: 1px solid var(--red);
  color: var(--text);
  padding: 0.5rem 0.85rem;
  font-size: 0.95rem;
}
.sol-numeric {
  font-family: var(--mono);
  font-size: 0.8rem;
  color: var(--muted);
  margin-top: 0.3rem;
}

/* ----- Pași backtracking ----- */
.out-steps-wrap { margin-top: 1.2rem; }
.btn-steps {
  font-family: var(--mono);
  font-size: 0.78rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}
#out-steps {
  margin-top: 0.6rem;
  border: 1px solid var(--border);
  background: var(--bg);
  padding: 0.7rem 0.9rem;
  max-height: 26rem;
  overflow-y: auto;
}
.step-info {
  font-family: var(--mono);
  font-size: 0.74rem;
  color: var(--muted);
  margin-bottom: 0.5rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}
.step-list { display: flex; flex-direction: column; gap: 0.15rem; }
.step {
  font-family: var(--mono);
  font-size: 0.82rem;
  padding: 0.2rem 0.5rem;
  border-left: 2px solid var(--border-2);
  white-space: nowrap;
  overflow-x: auto;
}
.step-ok   { border-left-color: #95d5b2; color: var(--text); }
.step-no   { border-left-color: var(--faint); color: var(--muted); }
.step-sol  { border-left-color: var(--red); color: var(--red); font-weight: bold; background: rgba(230, 57, 70, 0.06); }
.step-back { border-left-color: #ffd166; color: var(--muted); font-style: italic; }

/* ===== Quiz ===== */
#quiz {
  max-width: 760px;
}
.quiz-box {
  border: 2px solid var(--red);
  background: var(--surface);
  padding: 1.5rem 1.7rem;
}
.q-count {
  font-family: var(--mono);
  font-size: 0.8rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--red);
  margin-bottom: 0.6rem;
}
.q-text {
  font-size: 1.1rem;
  margin-bottom: 1.2rem;
  line-height: 1.4;
}
.q-text code {
  font-family: var(--mono);
  background: var(--bg);
  padding: 0.1rem 0.4rem;
  border: 1px solid var(--border);
  color: var(--red-l);
  font-size: 0.9em;
}
.q-opts {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  margin-bottom: 1rem;
}
.q-opt {
  text-align: left;
  padding: 0.7rem 1rem;
  border: 1px solid var(--border);
  background: var(--bg);
  color: var(--text);
  cursor: pointer;
  font-family: var(--serif);
  font-size: 0.98rem;
  transition: all 0.15s;
}
.q-opt:hover:not(:disabled) {
  border-color: var(--red);
  background: var(--surface-2);
}
.q-opt.ok {
  border-color: var(--red);
  color: var(--red);
  font-weight: bold;
  background: rgba(230, 57, 70, 0.08);
}
.q-opt.no {
  border-color: var(--border);
  color: var(--faint);
  text-decoration: line-through;
}
.q-fb {
  padding: 0.8rem 1rem;
  background: var(--bg);
  border-left: 3px solid var(--red);
  font-size: 0.95rem;
  margin-bottom: 1rem;
  display: none;
}
.q-fb.show { display: block; }
.q-fb strong { color: var(--red); }
.q-controls {
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.q-score {
  font-family: var(--mono);
  font-size: 0.85rem;
  color: var(--muted);
}
.btn {
  background: var(--red);
  color: #ffffff;
  border: none;
  padding: 0.55rem 1.3rem;
  cursor: pointer;
  font-family: var(--serif);
  font-size: 0.95rem;
  letter-spacing: 0.02em;
  transition: background 0.2s;
}
.btn:hover { background: var(--red-d); }
.btn:disabled { opacity: 0.4; cursor: not-allowed; }

.q-final {
  text-align: center;
  padding: 2rem 1rem;
}
.q-final .score {
  font-size: 4.5rem;
  color: var(--red);
  font-weight: bold;
  line-height: 1;
  margin: 0.5rem 0;
}
.q-final .msg {
  color: var(--muted);
  margin-bottom: 1.5rem;
  font-size: 1.05rem;
}

/* ===== Bibliografie ===== */
.biblio {
  padding-left: 1.5rem;
  color: var(--text);
  font-size: 0.97rem;
}
.biblio li {
  padding: 0.4rem 0;
}
.biblio li em { color: var(--red); }

/* ===== Footer ===== */
footer {
  border-top: 2px solid var(--red);
  padding: 1.5rem 0;
  margin-top: 2rem;
  background: #000000;
}
.foot {
  display: flex;
  justify-content: space-between;
  font-size: 0.9rem;
  color: var(--muted);
  padding: 0 1.5rem;
}

/* ===== Responsive ===== */
@media (max-width: 780px) {
  .nav { flex-direction: column; gap: 0.5rem; padding: 0.7rem 1rem; }
  nav { display: flex; flex-wrap: wrap; justify-content: center; }
  nav a { margin: 0.2rem 0.5rem; font-size: 0.85rem; }
  h1 { font-size: 2rem; }
  h2 { font-size: 1.4rem; }
  section { padding: 2.5rem 0; }
  .foot { flex-direction: column; gap: 0.4rem; text-align: center; }
  .block { padding: 1rem 1.1rem; }
  .code { font-size: 0.78rem; }
  .constructor-grid { grid-template-columns: 1fr; }
  .cp-input { width: 100%; }
  .constructor-params { gap: 0.7rem; }
}

/* ===== Calculator Arbori (section #arbori) ===== */
#arbori .arbori-tabs {
  display: flex; gap: 0; border-bottom: 1px solid var(--border);
  margin-bottom: 1.1rem;
}
#arbori .arbori-tab {
  background: transparent; border: none;
  padding: 0.7rem 1.3rem 0.65rem;
  font-family: var(--mono); font-size: 0.82rem;
  letter-spacing: 0.08em; text-transform: uppercase;
  color: var(--muted); cursor: pointer;
  border-bottom: 2px solid transparent;
  margin-bottom: -1px; transition: all 0.15s;
}
#arbori .arbori-tab:hover { color: var(--text); }
#arbori .arbori-tab.active { color: var(--red); border-bottom-color: var(--red); }

#arbori .arbori-tab-panel { display: none; }
#arbori .arbori-tab-panel.active { display: block; }

#arbori .arbori-input-row {
  display: flex; gap: 0.7rem; align-items: flex-end;
  flex-wrap: wrap; margin-bottom: 0.7rem;
}
#arbori .arbori-field { display: flex; flex-direction: column; gap: 0.3rem; }
#arbori .arbori-field label {
  font-family: var(--mono); font-size: 0.72rem;
  letter-spacing: 0.1em; text-transform: uppercase;
  color: var(--muted);
}
#arbori .arbori-field input,
#arbori .arbori-field select,
#arbori .arbori-field textarea {
  background: var(--bg); color: var(--text);
  border: 1px solid var(--border);
  padding: 0.5rem 0.7rem; font-family: var(--mono);
  font-size: 0.92rem; outline: none;
  transition: border-color 0.15s;
}
#arbori .arbori-field input:focus,
#arbori .arbori-field select:focus,
#arbori .arbori-field textarea:focus { border-color: var(--red); }
#arbori .arbori-field input[type=number] { width: 90px; }
#arbori .arbori-field select { min-width: 240px; }
#arbori .arbori-field textarea { width: 100%; resize: vertical; min-height: 4.5rem; line-height: 1.55; }
#arbori .arbori-field textarea.arbori-matrix-input { min-height: 7rem; font-size: 0.85rem; }

#arbori .arbori-actions {
  display: flex; gap: 0.6rem; margin-top: 1.1rem;
  flex-wrap: wrap; align-items: center;
}
#arbori .arbori-status {
  font-family: var(--mono); font-size: 0.8rem;
  color: var(--muted); margin-left: auto;
}
#arbori .arbori-status.error { color: var(--red); }
#arbori .arbori-status.ok    { color: #6bbf6e; }

/* Analysis layout — panel takes full width */
#arbori .arbori-viz {
  display: block;
  margin-bottom: 1.6rem;
}

/* Analysis panel */
#arbori .arbori-panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-left: 3px solid var(--red);
  padding: 0;
}
#arbori .panel-head {
  padding: 0.85rem 1.1rem;
  border-bottom: 1px solid var(--border);
  font-family: var(--mono); font-size: 0.78rem;
  letter-spacing: 0.15em; text-transform: uppercase;
  color: var(--red);
  display: flex; justify-content: space-between; align-items: center;
}
#arbori .panel-body { padding: 0.7rem 1.1rem 1.1rem; }
#arbori .panel-group { padding: 0.7rem 0; border-bottom: 1px dashed var(--border); }
#arbori .panel-group:last-child { border-bottom: none; }
#arbori .panel-group .prow {
  display: flex; justify-content: space-between; align-items: baseline;
  gap: 0.6rem; margin: 0.18rem 0;
}
#arbori .panel-group .pk {
  color: var(--muted); font-size: 0.92rem;
  display: inline-flex; align-items: baseline; gap: 0.4rem;
}
#arbori .panel-group .pv {
  font-family: var(--mono); font-size: 0.95rem;
  color: var(--text); text-align: right;
}
#arbori .panel-group .pv.big {
  color: var(--red); font-size: 1.1rem; font-weight: bold;
}
#arbori .panel-group h4 {
  font-family: var(--mono); font-size: 0.72rem;
  letter-spacing: 0.12em; text-transform: uppercase;
  color: var(--muted); margin-bottom: 0.4rem;
}
#arbori .arbori-cap {
  font-family: var(--mono); font-size: 0.72rem;
  color: var(--muted); letter-spacing: 0.08em;
  margin-bottom: 0.2rem;
}
#arbori .help {
  display: inline-flex; align-items: center; justify-content: center;
  width: 16px; height: 16px;
  border: 1px solid var(--border-2);
  color: var(--faint); font-size: 0.65rem;
  font-family: var(--mono); cursor: help;
  border-radius: 50%; transition: all 0.15s;
  position: relative;
}
#arbori .help:hover { color: var(--red); border-color: var(--red); }
#arbori .help[data-tip]::after {
  content: attr(data-tip);
  position: absolute; top: calc(100% + 6px); left: 50%;
  transform: translateX(-50%);
  background: var(--surface-2);
  border: 1px solid var(--red);
  padding: 0.45rem 0.65rem;
  font-family: var(--serif); font-size: 0.82rem;
  color: var(--text); white-space: normal;
  width: 220px; opacity: 0;
  pointer-events: none;
  transition: opacity 0.15s;
  z-index: 20; line-height: 1.45;
  letter-spacing: normal; text-transform: none;
  box-shadow: 0 4px 18px rgba(0,0,0,0.5);
}
#arbori .help:hover::after { opacity: 1; }

#arbori .node-chip {
  display: inline-block;
  font-family: var(--mono); font-size: 0.82rem;
  padding: 0.12rem 0.5rem;
  background: var(--surface-2);
  border: 1px solid var(--border);
  color: var(--text);
  cursor: pointer; margin: 0.12rem 0.18rem 0.12rem 0;
  transition: all 0.12s;
}
#arbori .node-chip:hover { border-color: var(--red); color: var(--red); }
#arbori .node-chip.is-leaf { border-color: var(--amber); color: var(--amber); }
#arbori .node-chip.is-root { border-color: var(--red);   color: var(--red); }
#arbori .node-chip.is-max  { border-color: var(--red-l); color: var(--red-l); background: rgba(255,90,107,0.08); }
#arbori .node-chip.is-active { background: var(--gold); color: var(--bg); border-color: var(--gold); }

#arbori .arbori-sel-row {
  display: flex; gap: 0.5rem; align-items: center;
  margin-bottom: 0.5rem;
}
#arbori .arbori-sel-row input {
  background: var(--bg); color: var(--text);
  border: 1px solid var(--border); padding: 0.4rem 0.55rem;
  font-family: var(--mono); width: 70px; font-size: 0.9rem;
}
#arbori .arbori-sel-row label {
  font-family: var(--mono); font-size: 0.72rem;
  letter-spacing: 0.1em; text-transform: uppercase;
  color: var(--muted);
}

#arbori .arbori-traversal {
  font-family: var(--mono); font-size: 0.88rem;
  color: var(--text); word-break: break-all;
  padding: 0.45rem 0.55rem;
  background: var(--surface-2);
  border-left: 2px solid var(--red);
  margin-top: 0.3rem;
}
#arbori .arbori-traversal .lvl { color: var(--faint); margin-right: 0.4rem; }

#arbori .panel-body {
  columns: 2 320px;
  column-gap: 1.8rem;
}
#arbori .panel-group {
  break-inside: avoid;
  -webkit-column-break-inside: avoid;
}

@media (max-width: 780px) {
  #arbori .panel-body { grid-template-columns: 1fr; }
}
@media (max-width: 640px) {
  #arbori .arbori-tab { padding: 0.6rem 0.9rem; font-size: 0.74rem; }
}

/* ===== Recursion Builder (section #recbuild) ===== */
#recbuild .rb-card {
  background: var(--surface); border: 1px solid var(--border);
  border-left: 3px solid var(--red);
  padding: 1.1rem 1.3rem; margin-bottom: 1.1rem;
}
#recbuild .rb-card h3 { margin-bottom: 0.6rem; }
#recbuild .rb-section-label {
  font-family: var(--mono); font-size: 0.72rem;
  letter-spacing: 0.14em; text-transform: uppercase;
  color: var(--red); margin-bottom: 0.4rem;
}
#recbuild .rb-header {
  display: flex; flex-wrap: wrap; gap: 0.55rem;
  align-items: center; padding: 0.7rem 0.9rem;
  background: var(--bg); border: 1px dashed var(--border-2);
  font-family: var(--mono); font-size: 0.95rem;
  margin-bottom: 0.7rem;
}
#recbuild .rb-header .kw { color: var(--red-l); font-weight: bold; }
#recbuild .rb-header select,
#recbuild .rb-header input,
#recbuild .rb-row select,
#recbuild .rb-row input {
  background: var(--surface-2); color: var(--text);
  border: 1px solid var(--border); padding: 0.3rem 0.45rem;
  font-family: var(--mono); font-size: 0.88rem;
  outline: none; transition: border-color 0.12s;
}
#recbuild input.rb-tiny { width: 4.5rem; }
#recbuild input.rb-name { width: 6.5rem; }
#recbuild input.rb-expr { width: 14rem; }
#recbuild input.rb-expr-lg { width: 22rem; max-width: 100%; }
#recbuild input:focus,
#recbuild select:focus { border-color: var(--red); }
#recbuild .rb-pill {
  font-family: var(--mono); font-size: 0.72rem;
  letter-spacing: 0.1em; text-transform: uppercase;
  color: var(--muted); padding: 0.15rem 0.4rem;
  border: 1px solid var(--border-2);
}
#recbuild .rb-param-row { display: inline-flex; gap: 0.3rem; align-items: center; }
#recbuild .rb-param-x {
  background: transparent; border: none; color: var(--faint);
  font-family: var(--mono); font-size: 0.95rem; cursor: pointer;
  padding: 0 0.25rem;
}
#recbuild .rb-param-x:hover { color: var(--red); }

#recbuild .rb-palette {
  display: flex; flex-wrap: wrap; gap: 0.4rem;
  padding: 0.55rem 0.7rem;
  background: var(--bg); border: 1px dashed var(--border-2);
  margin: 0.45rem 0 0.4rem;
}
#recbuild .rb-pal-btn {
  background: var(--surface-2); border: 1px solid var(--border);
  color: var(--text); padding: 0.32rem 0.7rem;
  font-family: var(--mono); font-size: 0.82rem;
  letter-spacing: 0.05em; cursor: pointer;
  transition: all 0.12s;
}
#recbuild .rb-pal-btn:hover {
  border-color: var(--red); color: var(--red); background: var(--surface);
}
#recbuild .rb-pal-label {
  font-family: var(--mono); font-size: 0.7rem;
  color: var(--muted); letter-spacing: 0.08em;
  text-transform: uppercase; margin-right: 0.3rem;
  align-self: center;
}

#recbuild .rb-body {
  border: 1px solid var(--border); background: var(--bg);
  padding: 0.7rem; min-height: 3rem;
}
#recbuild .rb-body.rb-nested {
  margin-top: 0.45rem; padding: 0.55rem;
  border-left: 2px solid var(--red);
}
#recbuild .rb-empty {
  font-family: var(--mono); font-size: 0.78rem;
  color: var(--faint); padding: 0.2rem 0.3rem;
}

#recbuild .rb-block {
  border: 1px solid var(--border); background: var(--surface);
  margin-bottom: 0.5rem;
}
#recbuild .rb-block-head {
  display: flex; align-items: center; gap: 0.5rem;
  padding: 0.45rem 0.7rem;
  background: var(--surface-2);
  border-bottom: 1px solid var(--border);
}
#recbuild .rb-type {
  font-family: var(--mono); font-size: 0.72rem;
  letter-spacing: 0.12em; text-transform: uppercase;
  color: var(--red); font-weight: bold; min-width: 5.5rem;
}
#recbuild .rb-block-body {
  padding: 0.55rem 0.7rem; font-family: var(--mono);
  font-size: 0.88rem; line-height: 1.7;
  color: var(--text);
}
#recbuild .rb-block-body .kw { color: var(--red-l); font-weight: bold; }
#recbuild .rb-block-body .sep { color: var(--muted); }
#recbuild .rb-ctrl {
  margin-left: auto; display: inline-flex; gap: 0.15rem;
}
#recbuild .rb-ctrl button {
  background: transparent; border: 1px solid var(--border);
  color: var(--muted); font-family: var(--mono);
  font-size: 0.78rem; padding: 0.15rem 0.45rem; cursor: pointer;
  transition: all 0.12s;
}
#recbuild .rb-ctrl button:hover {
  color: var(--red); border-color: var(--red);
}

#recbuild .rb-run {
  display: flex; gap: 0.6rem; align-items: center;
  flex-wrap: wrap; padding: 0.85rem 1rem;
  background: var(--bg); border: 1px dashed var(--border-2);
  margin: 0.9rem 0 0.6rem;
}
#recbuild .rb-run label {
  font-family: var(--mono); font-size: 0.72rem;
  text-transform: uppercase; letter-spacing: 0.1em;
  color: var(--muted);
}
#recbuild .rb-run input {
  background: var(--surface); border: 1px solid var(--border);
  color: var(--text); padding: 0.45rem 0.6rem;
  font-family: var(--mono); font-size: 0.92rem;
  outline: none; width: 12rem;
}
#recbuild .rb-result {
  margin-top: 0.6rem; padding: 1rem 1.2rem;
  background: var(--surface); border: 2px solid var(--red);
}
#recbuild .rb-result .rb-result-final {
  font-family: var(--mono); font-size: 1.35rem;
  color: var(--red); font-weight: bold;
}
#recbuild .rb-result-meta {
  font-family: var(--mono); font-size: 0.82rem;
  color: var(--muted); margin-top: 0.3rem;
}
#recbuild .rb-error {
  font-family: var(--mono); font-size: 0.88rem;
  color: var(--red); background: rgba(230,57,70,0.08);
  border-left: 3px solid var(--red);
  padding: 0.55rem 0.8rem; margin-top: 0.5rem;
  white-space: pre-wrap;
}
#recbuild .rb-tree-wrap {
  margin-top: 0.7rem; max-height: 24rem; overflow: auto;
  background: var(--bg); border: 1px solid var(--border);
  padding: 0.55rem 0.7rem;
}
#recbuild .rb-tree-node {
  font-family: var(--mono); font-size: 0.85rem;
  margin: 0.1rem 0;
}
#recbuild .rb-tree-node .rb-toggle {
  display: inline-block; width: 1rem; cursor: pointer;
  color: var(--red); user-select: none;
}
#recbuild .rb-tree-node .rb-call {
  color: var(--text);
}
#recbuild .rb-tree-node .rb-call .rb-callname { color: var(--red-l); }
#recbuild .rb-tree-node .rb-call .rb-callres { color: var(--gold); }
#recbuild .rb-tree-children { margin-left: 1.2rem; border-left: 1px dashed var(--border); padding-left: 0.6rem; }

#recbuild .rb-tests {
  display: flex; flex-wrap: wrap; gap: 0.4rem;
  margin: 0.6rem 0 0;
}
#recbuild .rb-test-badge {
  font-family: var(--mono); font-size: 0.78rem;
  padding: 0.25rem 0.6rem; border: 1px solid var(--border);
  background: var(--bg);
}
#recbuild .rb-test-badge.ok   { border-color: #6bbf6e; color: #6bbf6e; }
#recbuild .rb-test-badge.fail { border-color: var(--red); color: var(--red); background: rgba(230,57,70,0.08); }
#recbuild .rb-actions {
  display: flex; gap: 0.5rem; align-items: center;
  flex-wrap: wrap; margin-top: 0.4rem;
}