:root {
  --bg: #0e1116;
  --surface: #161b22;
  --surface-2: #1f2630;
  --border: #2a323d;
  --text: #e6edf3;
  --text-dim: #9aa6b2;
  --accent: #58a6ff;
  --stable: #57c98a;
  --changed: #f85149;
  --proof: #d29922;
  --sibling: #c678dd;
  --selected: #2dd4bf;
  --code: "JetBrains Mono", "SF Mono", Menlo, Consolas, monospace;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font: 15px/1.55 -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui,
    sans-serif;
}

main {
  max-width: 960px;
  margin: 0 auto;
  padding: 32px 20px 80px;
}

header {
  margin-bottom: 28px;
}

h1 {
  font-size: 28px;
  margin: 0 0 8px;
  letter-spacing: -0.01em;
}

h2 {
  font-size: 14px;
  font-weight: 600;
  margin: 0;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-dim);
}

.lede {
  margin: 0;
  color: var(--text-dim);
  max-width: 720px;
}

.lede strong {
  color: var(--text);
}

code,
.root-hash,
.proof-card-hash {
  font-family: var(--code);
  font-size: 12.5px;
}

section {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 18px 18px 20px;
  margin-bottom: 18px;
}

.section-head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  margin-bottom: 14px;
}

button {
  background: var(--surface-2);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 6px 12px;
  border-radius: 6px;
  font: inherit;
  font-size: 13px;
  cursor: pointer;
}

button:hover {
  border-color: var(--accent);
  color: var(--accent);
}

/* ────────── leaves ────────── */

.leaves {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.leaf-row {
  display: grid;
  grid-template-columns: 32px 1fr auto auto;
  gap: 10px;
  align-items: center;
}

.leaf-index {
  text-align: right;
  font-family: var(--code);
  color: var(--text-dim);
  font-size: 12px;
}

.leaf-input {
  background: var(--surface-2);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 8px 10px;
  border-radius: 6px;
  font-family: var(--code);
  font-size: 13px;
  outline: none;
  transition: border-color 0.12s, box-shadow 0.12s;
}

.leaf-input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 2px rgba(88, 166, 255, 0.25);
}

.leaf-row.selected .leaf-input {
  border-color: var(--selected);
}

.leaf-row.changed .leaf-input {
  border-color: var(--changed);
}

.leaf-tamper,
.leaf-remove {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text-dim);
  font-size: 12px;
  padding: 4px 8px;
}

.leaf-tamper:hover {
  color: var(--changed);
  border-color: var(--changed);
}

.leaf-remove:hover {
  color: var(--changed);
  border-color: var(--changed);
}

.leaves-actions {
  display: flex;
  gap: 8px;
}

.leaves-hint {
  margin: 12px 0 0;
  color: var(--text-dim);
  font-size: 12.5px;
}

/* ────────── tree ────────── */

.tree-wrap {
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 12px;
  overflow-x: auto;
}

#tree {
  display: block;
  width: 100%;
  height: auto;
  min-height: 280px;
}

.node-rect {
  fill: var(--surface);
  stroke: #3a4654;
  stroke-width: 1.5;
  transition: fill 0.18s, stroke 0.18s;
}

.node-rect.stable {
  stroke: #3a4654;
}

.node-rect.changed {
  fill: rgba(248, 81, 73, 0.16);
  stroke: var(--changed);
}

.node-rect.proof {
  fill: rgba(210, 153, 34, 0.18);
  stroke: var(--proof);
}

.node-rect.sibling {
  fill: rgba(198, 120, 221, 0.18);
  stroke: var(--sibling);
}

.node-rect.selected {
  fill: rgba(45, 212, 191, 0.18);
  stroke: var(--selected);
  stroke-width: 2;
}

.node-rect.leaf {
  cursor: pointer;
}

.node-hash {
  fill: var(--text);
  font-family: var(--code);
  font-size: 11px;
  pointer-events: none;
  user-select: none;
}

.node-label {
  fill: var(--text-dim);
  font-family: var(--code);
  font-size: 9.5px;
  pointer-events: none;
  user-select: none;
}

.tree-edge {
  stroke: #3a4654;
  stroke-width: 1.5;
  fill: none;
  transition: stroke 0.18s;
}

.tree-edge.changed {
  stroke: var(--changed);
}

.tree-edge.proof {
  stroke: var(--proof);
}

.root-display {
  display: flex;
  align-items: center;
  gap: 8px;
}

.root-label {
  color: var(--text-dim);
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.root-hash {
  background: var(--surface-2);
  padding: 4px 10px;
  border-radius: 4px;
  border: 1px solid var(--border);
  font-size: 12px;
}

.legend {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 12px;
  font-size: 12px;
  color: var(--text-dim);
}

.legend-item {
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.dot {
  width: 10px;
  height: 10px;
  border-radius: 2px;
  display: inline-block;
}

.dot-stable {
  background: #3a4654;
}
.dot-changed {
  background: var(--changed);
}
.dot-proof {
  background: var(--proof);
}
.dot-sibling {
  background: var(--sibling);
}
.dot-selected {
  background: var(--selected);
}

/* ────────── proof ────────── */

.proof-status {
  font-size: 12.5px;
  color: var(--text-dim);
}

.proof-status.ok {
  color: var(--stable);
}

.proof-status.bad {
  color: var(--changed);
}

.proof-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
}

@media (min-width: 700px) {
  .proof-grid {
    grid-template-columns: 1fr 1.4fr 1fr;
  }
}

.proof-card {
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 12px;
}

.proof-card-label {
  font-size: 11px;
  color: var(--text-dim);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: 6px;
}

.proof-card-value {
  font-family: var(--code);
  font-size: 13px;
  word-break: break-all;
  margin-bottom: 12px;
}

.proof-card-hash {
  display: block;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 6px 8px;
  word-break: break-all;
  font-size: 11.5px;
  margin-bottom: 8px;
}

.proof-list {
  margin: 0;
  padding-left: 20px;
  font-family: var(--code);
  font-size: 11.5px;
  line-height: 1.7;
}

.proof-list li {
  word-break: break-all;
}

.proof-list .side {
  display: inline-block;
  width: 38px;
  color: var(--text-dim);
}

.proof-list .empty-hint {
  color: var(--text-dim);
  font-style: italic;
  list-style: none;
  margin-left: -20px;
}

.verify-result {
  font-weight: 600;
  font-family: var(--code);
  font-size: 13px;
  padding: 6px 8px;
  border-radius: 4px;
  margin-top: 4px;
}

.verify-result.ok {
  background: rgba(87, 201, 138, 0.15);
  color: var(--stable);
}

.verify-result.bad {
  background: rgba(248, 81, 73, 0.15);
  color: var(--changed);
}

.verify-tamper {
  margin-top: 10px;
  font-size: 12px;
  color: var(--text-dim);
}

.verify-tamper summary {
  cursor: pointer;
  user-select: none;
}

.verify-tamper input {
  margin-top: 8px;
  width: 100%;
  background: var(--bg);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 6px 8px;
  border-radius: 4px;
  font-family: var(--code);
  font-size: 12px;
}

.tiny {
  font-size: 11.5px;
  color: var(--text-dim);
  margin: 6px 0 0;
}

/* ────────── footer ────────── */

footer {
  margin-top: 32px;
  font-size: 12.5px;
  color: var(--text-dim);
}

footer a {
  color: var(--accent);
  text-decoration: none;
}

footer a:hover {
  text-decoration: underline;
}

footer p {
  margin: 4px 0;
}