:root {
  color-scheme: dark;
  --bg: #0f1115;
  --bg-2: #161a21;
  --card: #1b2029;
  --card-2: #222834;
  --line: #2c3442;
  --text: #e8eaee;
  --muted: #9aa3b2;
  --accent: #f0a63a;
  --accent-2: #ffcf7a;
  --ok: #4fc38a;
  --warn: #f2c14e;
  --bad: #f06a5e;
  --info: #6aa8ff;
  --radius: 14px;
  --radius-sm: 8px;
  --gap: 14px;
  --font: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --mono: ui-monospace, "SF Mono", Menlo, monospace;

  --chart-grid: #283040;
  --chart-text: #8a93a3;
  --chart-cursor: #ffffffaa;

  --c-surface: #6aa8ff;
  --c-core: #f06a5e;
  --c-interface: #b48cff;
  --c-air: #7f8a99;
  --c-tg: #4fc38a;
  --c-alpha: #f0a63a;
  --c-shore: #e8eaee;
  --c-pot: #ff8f5a;
  --c-base: #8a93a3;

  accent-color: var(--accent);
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: var(--font);
  font-size: 0.875rem;
  line-height: 1.45;
  background: radial-gradient(1200px 600px at 80% -10%, #2a1f0e55, transparent 60%), var(--bg);
  color: var(--text);
  min-block-size: 100dvh;
}

h1, h2 { margin: 0; text-wrap: balance; }
h1 { font-size: 1.15rem; letter-spacing: 0.01em; }
h2 { font-size: 0.95rem; font-weight: 600; }
code { font-family: var(--mono); font-size: 0.8em; background: var(--card-2); padding: 0.1em 0.35em; border-radius: 4px; }

/* ---------- Top bar ---------- */
.topbar {
  display: flex; align-items: center; justify-content: space-between; gap: var(--gap);
  padding: 12px 20px; border-block-end: 1px solid var(--line);
  background: color-mix(in oklab, var(--bg) 85%, transparent);
  position: sticky; inset-block-start: 0; z-index: 5;
  backdrop-filter: blur(8px);
}
.brand { display: flex; align-items: center; gap: 12px; }
.brand p { margin: 0; color: var(--muted); font-size: 0.8rem; }
.logo { display: inline-flex; gap: 3px; }
.logo i { inline-size: 14px; block-size: 28px; border-radius: 4px; display: block; }
.logo i:first-child { background: linear-gradient(#f7e7c4, #d9c9a8); }
.logo i:last-child { background: linear-gradient(#ffcf7a, #c4761a); }
.top-actions { display: flex; gap: 8px; flex-wrap: wrap; }

.btn {
  font: inherit; color: var(--text); background: var(--card-2); border: 1px solid var(--line);
  border-radius: var(--radius-sm); padding: 6px 12px; cursor: pointer; min-block-size: 32px;
  transition: background-color 0.15s, border-color 0.15s;
}
.btn:hover { border-color: var(--accent); }
.btn.ghost { background: transparent; }
.btn.icon { inline-size: 36px; padding: 0; }
.btn:focus-visible, input:focus-visible, select:focus-visible, summary:focus-visible {
  outline: 2px solid var(--accent); outline-offset: 2px;
}

/* ---------- Layout ---------- */
.layout {
  display: grid; grid-template-columns: 330px 1fr; gap: var(--gap);
  padding: var(--gap) 20px 40px; align-items: start;
}
@media (max-width: 960px) { .layout { grid-template-columns: 1fr; } }

.controls {
  position: sticky; inset-block-start: 76px; max-block-size: calc(100dvh - 90px); overflow: auto;
  display: flex; flex-direction: column; gap: 10px; padding-inline-end: 4px;
  scrollbar-width: thin; scrollbar-color: var(--line) transparent;
}
@media (max-width: 960px) { .controls { position: static; max-block-size: none; } }

.group {
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 0;
}
.group > summary {
  list-style: none; cursor: pointer; padding: 10px 14px; display: flex; align-items: center; justify-content: space-between;
  font-weight: 600; font-size: 0.85rem; letter-spacing: 0.02em;
}
.group > summary::-webkit-details-marker { display: none; }
.group > summary::after { content: "▾"; color: var(--muted); transition: rotate 0.2s; }
.group:not([open]) > summary::after { rotate: -90deg; }
.group .body { padding: 2px 14px 12px; display: flex; flex-direction: column; gap: 10px; }

.ctl { display: grid; gap: 4px; }
.ctl .row { display: flex; justify-content: space-between; align-items: baseline; gap: 8px; }
.ctl label { color: var(--muted); font-size: 0.8rem; }
.ctl output { font-family: var(--mono); font-size: 0.8rem; color: var(--accent-2); white-space: nowrap; }
.ctl .sub { color: var(--muted); font-size: 0.72rem; }
.ctl.check { grid-template-columns: auto 1fr; align-items: center; }
.ctl.disabled { opacity: 0.45; }

select {
  font: inherit; color: var(--text); background: var(--card-2); border: 1px solid var(--line);
  border-radius: var(--radius-sm); padding: 6px 8px; min-block-size: 32px; inline-size: 100%;
}

input[type=range] {
  appearance: none; inline-size: 100%; background: transparent; min-block-size: 22px; margin: 0;
}
input[type=range]::-webkit-slider-runnable-track {
  block-size: 4px; border-radius: 4px;
  background: linear-gradient(to right, var(--accent) var(--p, 50%), var(--line) var(--p, 50%));
}
input[type=range]::-moz-range-track { block-size: 4px; border-radius: 4px; background: var(--line); }
input[type=range]::-moz-range-progress { block-size: 4px; border-radius: 4px; background: var(--accent); }
input[type=range]::-webkit-slider-thumb {
  appearance: none; inline-size: 16px; block-size: 16px; border-radius: 50%; margin-block-start: -6px;
  background: var(--text); border: 3px solid var(--accent); cursor: pointer;
}
input[type=range]::-moz-range-thumb {
  inline-size: 12px; block-size: 12px; border-radius: 50%; background: var(--text); border: 3px solid var(--accent); cursor: pointer;
}

/* ---------- Main ---------- */
.main { display: flex; flex-direction: column; gap: var(--gap); min-inline-size: 0; }
.card {
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 12px 14px;
  min-inline-size: 0;
}
.card-head { display: flex; align-items: center; justify-content: space-between; gap: 10px; flex-wrap: wrap; margin-block-end: 8px; }
.hint { color: var(--muted); font-size: 0.75rem; margin: 6px 0 0; }
.card-head .hint { margin: 0; }
.grid2 { display: grid; grid-template-columns: repeat(auto-fit, minmax(380px, 1fr)); gap: var(--gap); }

.chart { inline-size: 100%; block-size: 220px; display: block; touch-action: pan-y; }
.chart.tall { block-size: 260px; }

.legend { display: flex; gap: 10px; flex-wrap: wrap; font-size: 0.72rem; color: var(--muted); }
.legend span { display: inline-flex; align-items: center; gap: 5px; }
.legend i { inline-size: 14px; block-size: 3px; border-radius: 2px; background: var(--c); display: inline-block; }
.legend i.dash { background: repeating-linear-gradient(to right, var(--c) 0 4px, transparent 4px 7px); }

/* KPIs */
.kpis { display: grid; grid-template-columns: repeat(auto-fit, minmax(140px, 1fr)); gap: 10px; }
.kpi {
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 10px 12px;
  border-block-start: 3px solid var(--k, var(--accent));
}
.kpi .lbl { color: var(--muted); font-size: 0.72rem; text-transform: uppercase; letter-spacing: 0.05em; }
.kpi .val { font-size: 1.3rem; font-weight: 650; font-variant-numeric: tabular-nums; margin-block: 2px; }
.kpi .sub { color: var(--muted); font-size: 0.72rem; }
.kpi .delta { font-size: 0.72rem; font-family: var(--mono); }
.kpi .delta.up { color: var(--bad); }
.kpi .delta.down { color: var(--ok); }
.kpi .delta.good-up { color: var(--ok); }
.kpi .delta.bad-down { color: var(--bad); }

/* Timeline */
.timeline { position: relative; block-size: 92px; margin-inline: 8px; }
.timeline .axis { position: absolute; inset-inline: 0; inset-block-start: 44px; block-size: 6px; border-radius: 6px;
  background: linear-gradient(to right, #f7e7c4, #ffcf7a 30%, #e08a2c 55%, #8a5a2b 80%, #5a4636); }
.timeline .tick { position: absolute; inset-block-start: 54px; font-size: 0.68rem; color: var(--muted); translate: -50% 0; }
.timeline .ms { position: absolute; translate: -50% 0; display: flex; flex-direction: column; align-items: center; gap: 2px; font-size: 0.7rem; white-space: nowrap; }
.timeline .ms.top { inset-block-start: 0; }
.timeline .ms.top::after { content: ""; inline-size: 2px; block-size: 12px; background: var(--c); }
.timeline .ms.bottom { inset-block-start: 66px; flex-direction: column-reverse; }
.timeline .ms b { color: var(--c); font-weight: 600; }
.timeline .ms span { color: var(--muted); font-family: var(--mono); font-size: 0.66rem; }

/* Cross-section */
.viz-wrap { display: grid; grid-template-columns: 1fr 230px; gap: 12px; }
@media (max-width: 700px) { .viz-wrap { grid-template-columns: 1fr; } }
.section-canvas { inline-size: 100%; block-size: 260px; display: block; border-radius: var(--radius-sm); background: var(--bg-2); }
.readout { margin: 0; display: grid; grid-template-columns: auto 1fr; gap: 4px 10px; align-content: start; font-size: 0.8rem; }
.readout dt { color: var(--muted); }
.readout dd { margin: 0; font-family: var(--mono); text-align: end; }
.readout .state { grid-column: 1 / -1; font-family: var(--font); font-weight: 650; font-size: 0.95rem; padding: 6px 10px; border-radius: var(--radius-sm); background: var(--card-2); border-inline-start: 4px solid var(--c, var(--accent)); margin-block-end: 6px; }
.scrubber { display: flex; align-items: center; gap: 10px; margin-block-start: 10px; }
.scrubber output { font-family: var(--mono); min-inline-size: 70px; text-align: end; color: var(--accent-2); }

.seg { display: inline-flex; background: var(--card-2); border: 1px solid var(--line); border-radius: 999px; padding: 2px; }
.seg label { padding: 3px 10px; border-radius: 999px; cursor: pointer; font-size: 0.75rem; color: var(--muted); }
.seg input { position: absolute; opacity: 0; pointer-events: none; }
.seg label:has(:checked) { background: var(--accent); color: #1a1205; font-weight: 600; }
.seg label:has(:focus-visible) { outline: 2px solid var(--accent); outline-offset: 2px; }

/* Properties */
.props { display: grid; gap: 8px; }
.prop { display: grid; grid-template-columns: 150px 1fr 90px; align-items: center; gap: 10px; font-size: 0.8rem; }
.prop .name { color: var(--muted); }
.prop .bar { block-size: 8px; background: var(--card-2); border-radius: 8px; overflow: hidden; }
.prop .bar i { display: block; block-size: 100%; inline-size: var(--w); background: var(--c, var(--accent)); border-radius: 8px; transition: inline-size 0.3s; }
.prop .v { font-family: var(--mono); text-align: end; }

/* Warnings */
.warnings { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 8px; }
.warnings li { padding: 8px 10px 8px 12px; border-radius: var(--radius-sm); background: var(--card-2); border-inline-start: 4px solid var(--c); font-size: 0.8rem; text-wrap: pretty; }
.warnings li.bad { --c: var(--bad); }
.warnings li.warn { --c: var(--warn); }
.warnings li.info { --c: var(--info); }
.warnings li.ok { --c: var(--ok); }

.notes summary { cursor: pointer; list-style: none; }
.notes summary h2 { display: inline; }
.notes ul { padding-inline-start: 18px; color: var(--muted); }
.notes li { margin-block: 4px; text-wrap: pretty; }
.notes b { color: var(--text); }
.disclaimer { color: var(--muted); font-size: 0.78rem; border-block-start: 1px solid var(--line); padding-block-start: 8px; text-wrap: pretty; }

@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; }
}
@media (pointer: coarse) {
  .btn, select { min-block-size: 40px; }
}

/* ---------- Custom Formulator Modal ---------- */
.btn.highlight {
  background: linear-gradient(135deg, #e08a2c, #f0a63a);
  color: #120e06;
  font-weight: 650;
  border-color: #ffcf7a;
  box-shadow: 0 2px 10px rgba(240, 166, 58, 0.25);
}
.btn.highlight:hover {
  background: linear-gradient(135deg, #f0a63a, #ffcf7a);
  border-color: #fff;
}
.btn.btn-lg {
  padding: 10px 18px;
  font-size: 0.95rem;
  min-block-size: 44px;
}

.modal-dialog {
  padding: 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--bg);
  color: var(--text);
  max-inline-size: 960px;
  inline-size: 94vw;
  max-block-size: 90dvh;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.7);
}
.modal-dialog::backdrop {
  background: rgba(8, 10, 14, 0.82);
  backdrop-filter: blur(6px);
}

.modal-content {
  display: flex;
  flex-direction: column;
  max-block-size: 90dvh;
}

.modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 16px 22px;
  border-block-end: 1px solid var(--line);
  background: var(--card);
}

.modal-body {
  padding: 18px 22px;
  overflow-y: auto;
}

.form-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 18px;
}
@media (max-width: 820px) {
  .form-grid { grid-template-columns: 1fr; }
}

.form-col {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.box {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  padding: 14px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.box h3 {
  margin: 0 0 4px;
  font-size: 0.88rem;
  color: var(--accent-2);
  display: flex;
  align-items: center;
  gap: 6px;
}

.f-group {
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.f-group label {
  font-size: 0.76rem;
  color: var(--muted);
  font-weight: 550;
  display: flex;
  justify-content: space-between;
}
.f-group output {
  font-family: var(--mono);
  color: var(--accent);
}
.form-sub-desc {
  font-size: 0.72rem;
  color: var(--muted);
  line-height: 1.35;
  background: var(--bg-2);
  padding: 4px 8px;
  border-radius: 4px;
  border-inline-start: 2px solid var(--line);
}

.f-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}
.f-row3 {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 8px;
}

.text-input {
  font: inherit;
  color: var(--text);
  background: var(--card-2);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  padding: 6px 10px;
  min-block-size: 32px;
  inline-size: 100%;
}
.color-picker {
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  block-size: 36px;
  inline-size: 100%;
  cursor: pointer;
  background: var(--card-2);
  padding: 2px;
}

.result-box {
  background: color-mix(in oklab, var(--card) 90%, var(--accent) 10%);
  border-color: color-mix(in oklab, var(--line) 80%, var(--accent) 20%);
}

.stoich-summary {
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.stoich-metric {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  padding: 6px 8px;
  background: var(--card-2);
  border-radius: 6px;
  font-size: 0.8rem;
}
.stoich-metric .lbl {
  color: var(--muted);
}
.stoich-metric .val {
  font-family: var(--mono);
  font-weight: 650;
  color: var(--text);
}
.stoich-metric.primary-metric {
  background: rgba(240, 166, 58, 0.15);
  border: 1px solid rgba(240, 166, 58, 0.35);
}
.stoich-metric.primary-metric .val {
  color: var(--accent-2);
  font-size: 1.05rem;
}

.action-bar {
  margin-block-start: 12px;
  display: flex;
  flex-direction: column;
}
.mt-3 {
  margin-block-start: 8px;
}