:root {
  --bg: #f6f7f9;
  --panel-bg: #ffffff;
  --text: #1a1d23;
  --muted: #5b6472;
  --border: #d8dce2;
  --accent: #3b6ff0;
  --accent-text: #ffffff;
  --danger: #d24545;
  --row-blocked: #fdeaea;
  --row-start: #eef2fb;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #14161a;
    --panel-bg: #1d2026;
    --text: #e7e9ee;
    --muted: #9aa3b2;
    --border: #333842;
    --accent: #6d93f7;
    --accent-text: #0c1220;
    --danger: #ef6a6a;
    --row-blocked: #3a1f22;
    --row-start: #202a41;
  }
}

* { box-sizing: border-box; }

html, body {
  /* safety net: nothing on this page should ever force page-wide
     horizontal scroll/zoom -- wide content (the steps table) scrolls
     inside its own .steps-scroll container instead. */
  overflow-x: hidden;
  max-width: 100%;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  line-height: 1.4;
}

#app {
  max-width: 1400px;
  margin: 0 auto;
  padding: 24px 20px 80px;
}

h1 { margin: 0 0 4px; font-size: 1.6rem; }
h2 { font-size: 1.15rem; margin: 0 0 12px; }
h3 { font-size: 0.95rem; margin: 16px 0 8px; color: var(--muted); }

.subtitle { color: var(--muted); margin: 0 0 20px; max-width: 70ch; }

.panel {
  background: var(--panel-bg);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 18px 20px;
  margin-bottom: 24px;
}

.tabs {
  display: flex;
  gap: 4px;
  border-bottom: 1px solid var(--border);
  margin-bottom: 20px;
}

.tab {
  background: transparent;
  border: none;
  border-bottom: 2px solid transparent;
  margin-bottom: -1px;
  padding: 10px 16px;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--muted);
  cursor: pointer;
}

.tab:hover { color: var(--text); }

.tab.active {
  color: var(--accent);
  border-bottom-color: var(--accent);
}

.tab-panel[hidden] { display: none; }

.input-with-mode { display: flex; gap: 6px; margin-top: auto; }
.input-with-mode input { flex: 1 1 auto; min-width: 0; }
.input-with-mode select {
  flex: 0 0 auto;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 6px 4px;
  color: var(--text);
  font-size: 0.82rem;
}
.maxed-check {
  flex: 0 0 auto;
  display: inline-flex;
  align-items: center;
  gap: 4px;
  white-space: nowrap;
  font-size: 0.78rem;
  color: var(--muted);
}
.maxed-check input { flex: 0 0 auto; }

.exp-chart {
  margin: 16px 0 8px;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 12px;
  background: var(--panel-bg);
}
.exp-chart[hidden] { display: none; }

.threshold-intro { color: var(--muted); margin: 12px 0 6px; }
.threshold-table {
  border-collapse: collapse;
  width: 100%;
  max-width: 520px;
  font-size: 0.9rem;
}
.threshold-table th, .threshold-table td {
  text-align: left;
  padding: 6px 12px 6px 0;
  border-bottom: 1px solid var(--border);
}
.threshold-table th { color: var(--muted); font-weight: 600; }
.threshold-table tr.threshold-target td { font-weight: 700; color: var(--accent); }

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 12px 16px;
}

label {
  display: flex;
  flex-direction: column;
  font-size: 0.82rem;
  color: var(--muted);
  gap: 4px;
}

label.checkbox-row {
  flex-direction: row;
  align-items: center;
  gap: 8px;
}

.label-text { display: inline-flex; align-items: center; gap: 5px; }

.info-icon {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 13px;
  height: 13px;
  border-radius: 50%;
  border: 1px solid var(--muted);
  color: var(--muted);
  font-size: 0.62rem;
  font-weight: 700;
  line-height: 1;
  cursor: help;
  flex: none;
}
.info-icon:hover, .info-icon:focus-visible {
  color: var(--text);
  border-color: var(--text);
}

.info-icon::after {
  content: attr(data-tooltip);
  position: absolute;
  top: calc(100% + 8px);
  left: 50%;
  transform: translateX(-50%) translateY(-4px);
  width: max-content;
  max-width: 240px;
  background: var(--text);
  color: var(--bg);
  font-size: 0.72rem;
  font-weight: 400;
  line-height: 1.35;
  text-align: left;
  white-space: normal;
  padding: 6px 9px;
  border-radius: 6px;
  box-shadow: 0 4px 14px rgba(0, 0, 0, 0.35);
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transition: opacity 0.1s ease, transform 0.1s ease;
  z-index: 20;
}
.info-icon:hover::after, .info-icon:focus-visible::after {
  opacity: 1;
  visibility: visible;
  transform: translateX(-50%) translateY(0);
}

label > input[type="number"], label > input[type="text"] {
  margin-top: auto;
}

input[type="number"], input[type="text"] {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 6px 8px;
  color: var(--text);
  font-size: 0.9rem;
}

.node-io { display: flex; align-items: center; gap: 4px; }
.io-sep { color: var(--muted); font-weight: 600; }
.node-io input { width: 82px; }
.node-io input.asc { text-align: right; }
.node-io input.lvl { text-align: left; }
/* hide number spinners so the placeholder text has room to show */
.node-io input::-webkit-outer-spin-button,
.node-io input::-webkit-inner-spin-button { -webkit-appearance: none; margin: 0; }
.node-io input { -moz-appearance: textfield; appearance: textfield; }

/* Singularity Tree star view: SVG scrolls/scales inside its own container
   (never the page) per PRODUCT.md's "match the game's radial layout"
   principle; the one place a glow/highlight departs from the rest of the
   flat, border-only system (DESIGN.md Elevation). */
.tree-viz-wrap {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-top: 8px;
}
.tree-viz-scroll {
  overflow-x: auto;
  overflow-y: hidden;
  padding: 4px;
}
.tree-viz-scroll svg { display: block; margin: 0 auto; }
.tree-editor-panel {
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 10px 14px;
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
  background: var(--panel-bg);
}
.tree-editor-panel h4 { margin: 0; font-size: 0.9rem; min-width: 64px; }
.tree-editor-panel .empty-hint { margin: 0; }
.node-cost-override { display: flex; align-items: center; gap: 6px; font-size: 0.82rem; color: var(--muted); }
.node-cost-override input { width: 90px; }
.node-cost-tag { font-style: italic; white-space: nowrap; }

.select-hint {
  display: block;
  color: var(--muted);
  font-size: 0.75rem;
  margin-top: 4px;
}

details.advanced { margin-top: 14px; }
details.advanced summary { cursor: pointer; color: var(--muted); font-size: 0.85rem; margin-bottom: 8px; }

.mult-breakdown { margin-top: 14px; }
.mult-breakdown summary { cursor: pointer; color: var(--muted); font-size: 0.85rem; margin-bottom: 8px; }
.mult-breakdown .grid { margin-top: 10px; }
.mult-breakdown-total { max-width: 220px; margin-bottom: 4px; }

input[readonly] {
  background: var(--row-start);
  color: var(--text);
  font-weight: 700;
  cursor: default;
}

.actions { margin-top: 18px; display: flex; gap: 10px; flex-wrap: wrap; }

.backup-bar {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
  margin-bottom: 16px;
}
.backup-bar .select-hint { margin-top: 0; flex-basis: 100%; }

button {
  border: 1px solid var(--border);
  background: var(--panel-bg);
  color: var(--text);
  border-radius: 6px;
  padding: 8px 14px;
  font-size: 0.85rem;
  cursor: pointer;
}
button:hover { border-color: var(--accent); }
button.primary { background: var(--accent); color: var(--accent-text); border-color: var(--accent); font-weight: 600; }
button.danger, .icon-btn.danger { color: var(--danger); border-color: var(--danger); }

.status { margin-top: 12px; font-size: 0.85rem; color: var(--muted); min-height: 1.2em; }
.status.error { color: var(--danger); }

.rush-node-panel {
  margin-top: 14px;
  padding: 12px 14px;
  border: 1px dashed var(--border);
  border-radius: 8px;
  background: var(--panel-bg);
}
.rush-node-panel h3 { margin: 0 0 10px; font-size: 0.95rem; }
.rush-node-panel .actions { margin-top: 12px; }

.quick-add-row { align-items: center; gap: 8px; margin-top: 10px; }
.quick-add-row .label-text { color: var(--muted); font-size: 0.82rem; }
.quick-add-btn { padding: 5px 10px; font-size: 0.8rem; }

.tree-rank {
  margin-top: 14px;
  padding: 12px 14px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--panel-bg);
  font-size: 0.85rem;
}
.tree-rank h3 {
  margin: 0 0 6px;
  font-size: 0.95rem;
}
.tree-rank .tree-rank-note {
  color: var(--muted);
  font-size: 0.8rem;
  margin: 0 0 10px;
}
.tree-rank table {
  width: 100%;
  border-collapse: collapse;
}
.tree-rank th,
.tree-rank td {
  text-align: left;
  padding: 5px 8px;
  border-bottom: 1px solid var(--border);
}
.tree-rank th { color: var(--muted); font-weight: 600; font-size: 0.75rem; }
.tree-rank tr.best-save td { color: var(--accent); font-weight: 600; }
.tree-rank .save-pos { color: #3d9a5f; }
.tree-rank .save-zero { color: var(--muted); }
.tree-rank .save-neg { color: var(--danger); }

.empty-hint { color: var(--muted); font-size: 0.9rem; }

#scenarios {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

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

.manager-row {
  display: flex;
  align-items: center;
  gap: 14px;
  flex-wrap: wrap;
  background: var(--panel-bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 8px 12px;
  font-size: 0.85rem;
}

.manager-title { font-weight: 600; min-width: 140px; }
.manager-stats { color: var(--muted); flex: 1; min-width: 160px; }
.manager-buttons { display: flex; gap: 6px; }
.manager-buttons button { padding: 4px 10px; font-size: 0.78rem; }
.manager-buttons button.toggle-on {
  background: var(--accent);
  color: var(--accent-text);
  border-color: var(--accent);
  font-weight: 700;
}

.compare-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  align-items: start;
}

@media (max-width: 900px) {
  .compare-grid { grid-template-columns: 1fr; }
}

.compare-pane { min-width: 0; }

.empty-pane {
  border: 1px dashed var(--border);
  border-radius: 10px;
  padding: 40px 16px;
  text-align: center;
  color: var(--muted);
  font-size: 0.85rem;
}

.slot-badge {
  background: var(--accent);
  color: var(--accent-text);
  font-weight: 700;
  font-size: 0.72rem;
  padding: 2px 8px;
  border-radius: 999px;
  flex-shrink: 0;
}

.scenario-card {
  background: var(--panel-bg);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 14px 16px;
}

.scenario-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  margin-bottom: 8px;
  flex-wrap: wrap;
}

.title-input {
  font-size: 1rem;
  font-weight: 600;
  border: 1px solid transparent;
  background: transparent;
  color: var(--text);
  padding: 4px 6px;
  border-radius: 6px;
  flex: 1;
  min-width: 180px;
}
.title-input:hover, .title-input:focus { border-color: var(--border); background: var(--bg); }

.scenario-buttons { display: flex; gap: 8px; }
.scenario-buttons button { padding: 5px 10px; font-size: 0.78rem; }

.scenario-summary {
  display: flex;
  gap: 20px;
  flex-wrap: wrap;
  font-size: 0.85rem;
  color: var(--muted);
  margin-bottom: 10px;
}
.scenario-summary strong { color: var(--text); }

.steps-scroll {
  overflow-x: auto;
  max-height: 480px;
  overflow-y: auto;
  border: 1px solid var(--border);
  border-radius: 8px;
}

.steps-table {
  border-collapse: collapse;
  width: 100%;
  font-size: 0.78rem;
  table-layout: auto;
}
.steps-table th, .steps-table td {
  padding: 4px 6px;
  border-bottom: 1px solid var(--border);
  text-align: left;
  white-space: nowrap;
}
.steps-table thead th {
  position: sticky;
  top: 0;
  background: var(--panel-bg);
  color: var(--muted);
  font-weight: 600;
  z-index: 1;
}
.steps-table tr.start-row { background: var(--row-start); }
.steps-table tr.run-row td { background: var(--row-start); }
.run-label { font-weight: 600; white-space: nowrap; }
.steps-table tr.blocked-row { background: var(--row-blocked); color: var(--danger); }
.steps-table select {
  background: var(--bg);
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: 5px;
  padding: 3px 4px;
  font-size: 0.74rem;
  max-width: 78px;
}
.mult-stack {
  display: flex;
  flex-direction: column;
  line-height: 1.25;
}
.mult-main { font-weight: 600; }
.delta { color: var(--muted); font-size: 0.7rem; }

.tm-sub { color: var(--muted); font-size: 0.68rem; }

.tree-stack {
  display: flex;
  flex-direction: column;
  line-height: 1.2;
  font-size: 0.72rem;
  gap: 1px;
}

.icon-btn {
  padding: 2px 6px;
  font-size: 0.85rem;
  line-height: 1;
  margin-right: 2px;
}

@media (max-width: 480px) {
  .steps-table { font-size: 0.68rem; }
  .steps-table th, .steps-table td { padding: 3px 3px; }
  .steps-table select { max-width: 58px; font-size: 0.66rem; }
  .icon-btn { padding: 1px 5px; margin-right: 1px; }
}

.scenario-footer {
  display: flex;
  gap: 8px;
  align-items: center;
  margin-top: 10px;
}
.scenario-footer button { font-size: 0.8rem; padding: 6px 10px; }
.scenario-footer .step-count { width: 60px; }

.error { color: var(--danger); }

.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.55);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
  z-index: 1000;
}
.modal {
  background: var(--panel-bg);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 10px;
  max-width: 560px;
  width: 100%;
  max-height: 80vh;
  overflow-y: auto;
  padding: 18px 20px;
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.5);
}
.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}
.modal-header h3 { margin: 0; font-size: 1rem; }
.modal-close {
  background: none;
  border: none;
  font-size: 1.4rem;
  line-height: 1;
  cursor: pointer;
  color: inherit;
  padding: 0 6px;
}
.modal-meta { font-size: 0.85rem; opacity: 0.8; margin: 6px 0 12px; }
.summary-list { margin: 0; padding-left: 22px; }
.summary-list li { margin: 6px 0; line-height: 1.4; }