:root {
  color-scheme: dark;
  --bg: #101317;
  --panel: #181d22;
  --panel-2: #20262d;
  --line: #303943;
  --text: #f3f6f8;
  --muted: #a9b4bf;
  --accent: #27c9a7;
  --accent-2: #f0b44c;
  --danger: #ff7777;
}

* {
  box-sizing: border-box;
}

html,
body {
  width: 100%;
  min-height: 100%;
  margin: 0;
}

body {
  background:
    linear-gradient(135deg, rgba(39, 201, 167, 0.11), transparent 30%),
    linear-gradient(315deg, rgba(240, 180, 76, 0.09), transparent 35%),
    var(--bg);
  color: var(--text);
  font-family:
    Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
    sans-serif;
}

button,
input {
  font: inherit;
}

.shell {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 340px;
  gap: 18px;
  min-height: 100vh;
  padding: 18px;
}

.workspace,
.info-panel {
  border: 1px solid var(--line);
  background: rgba(24, 29, 34, 0.9);
}

.workspace {
  display: grid;
  grid-template-rows: auto minmax(420px, 1fr);
  overflow: hidden;
  min-height: calc(100vh - 36px);
}

.toolbar {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 18px;
  padding: 14px;
  border-bottom: 1px solid var(--line);
  background: rgba(16, 19, 23, 0.72);
}

.formula-form {
  display: grid;
  gap: 8px;
  flex: 1;
  min-width: 260px;
}

label,
.eyebrow,
.fact-grid span {
  color: var(--muted);
  font-size: 12px;
  letter-spacing: 0;
}

.input-row {
  display: grid;
  grid-template-columns: minmax(140px, 1fr) auto;
  gap: 8px;
}

input {
  width: 100%;
  min-height: 42px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: #0e1114;
  color: var(--text);
  padding: 0 12px;
  outline: none;
}

input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(39, 201, 167, 0.14);
}

button {
  min-height: 40px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: var(--panel-2);
  color: var(--text);
  cursor: pointer;
  transition:
    border-color 140ms ease,
    background 140ms ease,
    transform 140ms ease;
}

button:hover {
  border-color: var(--accent);
  background: #263039;
}

button:active {
  transform: translateY(1px);
}

.formula-form button {
  padding: 0 18px;
  background: var(--accent);
  color: #061411;
  border-color: transparent;
  font-weight: 700;
}

.controls {
  display: flex;
  align-items: center;
  gap: 10px;
}

.icon-button {
  width: 42px;
  padding: 0;
  font-size: 23px;
  line-height: 1;
}

.segmented {
  display: flex;
  padding: 3px;
  gap: 3px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #0e1114;
}

.segmented button {
  min-height: 34px;
  padding: 0 12px;
  border-color: transparent;
  background: transparent;
  color: var(--muted);
}

.segmented button.active {
  background: var(--panel-2);
  color: var(--text);
}

.stage-wrap {
  position: relative;
  min-width: 0;
  min-height: 0;
}

.viewer {
  position: absolute;
  inset: 0;
}

.loading {
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  padding: 12px 16px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: rgba(14, 17, 20, 0.92);
  color: var(--text);
}

.hidden {
  display: none;
}

.info-panel {
  display: flex;
  flex-direction: column;
  gap: 20px;
  padding: 22px;
  min-height: calc(100vh - 36px);
}

.title-block {
  display: grid;
  gap: 10px;
}

.eyebrow {
  margin: 0;
  color: var(--accent);
  text-transform: uppercase;
}

h1 {
  margin: 0;
  font-size: clamp(28px, 4vw, 42px);
  line-height: 1.05;
  font-weight: 800;
}

.title-block p:last-child,
.notes p {
  margin: 0;
  color: var(--muted);
  line-height: 1.55;
}

.fact-grid {
  display: grid;
  gap: 10px;
}

.fact-grid div {
  display: grid;
  gap: 6px;
  padding: 12px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: #11161a;
}

.fact-grid strong {
  overflow-wrap: anywhere;
  font-size: 15px;
}

.notes {
  display: grid;
  gap: 8px;
  padding-top: 2px;
}

.examples {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: auto;
}

.examples button {
  min-height: 34px;
  padding: 0 10px;
  color: var(--accent-2);
}

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

@media (max-width: 860px) {
  .shell {
    grid-template-columns: 1fr;
  }

  .workspace,
  .info-panel {
    min-height: auto;
  }

  .workspace {
    grid-template-rows: auto 62vh;
  }

  .toolbar {
    align-items: stretch;
    flex-direction: column;
  }

  .controls {
    justify-content: space-between;
  }
}

@media (max-width: 520px) {
  .shell {
    padding: 10px;
    gap: 10px;
  }

  .input-row {
    grid-template-columns: 1fr;
  }

  .segmented {
    flex: 1;
  }

  .segmented button {
    flex: 1;
    padding: 0 8px;
  }
}