:root {
  color-scheme: light;
  --ink: #18211f;
  --muted: #65716d;
  --line: #d7dfdb;
  --surface: #f8faf8;
  --panel: #ffffff;
  --green: #1f7a4d;
  --teal: #0f766e;
  --blue: #2563a8;
  --gold: #b27613;
  --red: #b04235;
  --shadow: 0 16px 40px rgba(22, 35, 31, 0.08);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: var(--surface);
  color: var(--ink);
  overflow-x: hidden;
}

a {
  color: inherit;
}

.topbar {
  min-height: 64px;
  border-bottom: 1px solid var(--line);
  background: rgba(248, 250, 248, 0.96);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 24px;
  position: sticky;
  top: 0;
  z-index: 10;
  backdrop-filter: blur(12px);
}

.brand,
.topbar nav {
  display: flex;
  align-items: center;
  gap: 12px;
}

.brand {
  text-decoration: none;
  font-weight: 800;
}

.brand-mark {
  width: 32px;
  height: 32px;
  border-radius: 6px;
  display: inline-grid;
  place-items: center;
  background: var(--ink);
  color: #fff;
}

.topbar nav a {
  color: var(--muted);
  font-size: 14px;
  text-decoration: none;
}

.topbar nav a:hover {
  color: var(--ink);
}

main {
  padding: 28px;
}

.workspace {
  display: grid;
  grid-template-columns: minmax(330px, 450px) minmax(0, 1fr);
  gap: 20px;
  max-width: 1480px;
  margin: 0 auto;
}

.intro {
  grid-column: 1 / -1;
  display: grid;
  grid-template-columns: minmax(0, 760px) minmax(280px, 1fr);
  gap: 20px;
  align-items: end;
  border-bottom: 1px solid var(--line);
  padding-bottom: 18px;
}

.eyebrow {
  color: var(--green);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0;
  text-transform: uppercase;
  margin: 0 0 8px;
}

h1,
h2,
p {
  margin-top: 0;
}

h1 {
  font-size: clamp(38px, 5vw, 76px);
  line-height: 0.95;
  margin-bottom: 14px;
  letter-spacing: 0;
}

h2 {
  font-size: 18px;
  margin-bottom: 14px;
}

.lede {
  max-width: 860px;
  color: var(--muted);
  font-size: 18px;
  line-height: 1.55;
  margin-bottom: 0;
}

.control-panel,
.result-card {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: var(--shadow);
  min-width: 0;
}

.control-panel {
  align-self: start;
  position: sticky;
  top: 84px;
  padding: 18px;
}

.panel-heading,
.card-title,
.export-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
}

.preset-row {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

button {
  border: 1px solid var(--ink);
  background: var(--ink);
  color: #fff;
  min-height: 40px;
  border-radius: 6px;
  padding: 0 14px;
  font-weight: 750;
  cursor: pointer;
}

button.secondary,
button.ghost-button,
button.icon-button {
  background: #fff;
  color: var(--ink);
  border-color: var(--line);
}

button:hover {
  transform: translateY(-1px);
}

.form-grid {
  display: grid;
  gap: 14px;
}

fieldset {
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 14px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

legend {
  padding: 0 6px;
  font-weight: 800;
}

label {
  display: grid;
  gap: 6px;
  color: var(--muted);
  font-size: 13px;
  font-weight: 700;
}

label span {
  color: #81908a;
  font-weight: 600;
}

input {
  width: 100%;
  min-height: 40px;
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 8px 10px;
  color: var(--ink);
  font: inherit;
  background: #fff;
}

.results-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px;
}

.result-card {
  padding: 20px;
  min-width: 0;
}

.primary-result {
  min-height: 240px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  background: #f4f8f5;
}

.primary-result h2 {
  font-size: clamp(24px, 3vw, 38px);
  line-height: 1.05;
}

.big-number {
  font-size: clamp(38px, 5vw, 64px);
  font-weight: 850;
  color: var(--green);
}

.metric-label,
#bestReason,
footer {
  color: var(--muted);
  line-height: 1.45;
}

.visual-card {
  overflow: hidden;
}

#boxVisual {
  width: 100%;
  min-height: 270px;
  display: block;
  background: linear-gradient(180deg, #fbfcfb 0%, #edf3ef 100%);
  border-radius: 8px;
  border: 1px solid var(--line);
}

.metric-tiles {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.tile {
  min-height: 112px;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 14px;
  background: #fbfcfb;
}

.tile strong {
  display: block;
  font-size: 26px;
  margin: 6px 0;
}

.tile span {
  color: var(--muted);
  font-size: 13px;
}

.candidate-table {
  display: grid;
  gap: 10px;
}

.candidate-row {
  display: grid;
  grid-template-columns: 0.7fr 1.3fr 0.9fr 0.8fr 0.8fr;
  gap: 10px;
  align-items: center;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 12px;
  background: #fbfcfb;
}

.candidate-row.best {
  border-color: rgba(31, 122, 77, 0.6);
  background: #f1f8f3;
}

.candidate-row a,
.batch-row a,
.links-row a {
  color: var(--blue);
  font-weight: 750;
}

.bar {
  height: 8px;
  border-radius: 999px;
  overflow: hidden;
  background: #dfe7e3;
}

.bar span {
  display: block;
  height: 100%;
  background: var(--teal);
}

.notes-card {
  grid-column: 1 / -1;
}

.batch-card,
.formula-card,
.source-card {
  grid-column: 1 / -1;
}

.compact-actions {
  justify-content: flex-end;
  flex-wrap: wrap;
}

textarea {
  width: 100%;
  min-height: 150px;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 12px;
  resize: vertical;
  font: 13px/1.5 ui-monospace, SFMono-Regular, Menlo, monospace;
  color: var(--ink);
  background: #fbfcfb;
}

.batch-results,
.formula-grid,
.links-row {
  margin-top: 14px;
}

.batch-table {
  display: grid;
  gap: 10px;
}

.batch-row {
  display: grid;
  grid-template-columns: 0.8fr 1fr 1fr 0.7fr;
  gap: 10px;
  align-items: center;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 12px;
  background: #fbfcfb;
}

.batch-row span,
.formula-item span,
.source-card p {
  color: var(--muted);
}

.formula-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
}

.formula-item {
  min-height: 112px;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 14px;
  background: #fbfcfb;
}

.formula-item strong {
  display: block;
  margin-top: 8px;
  line-height: 1.35;
}

.links-row {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
}

.notes-card ul {
  margin: 0 0 18px;
  padding-left: 20px;
  color: var(--muted);
  line-height: 1.55;
}

footer {
  max-width: 1480px;
  margin: 0 auto;
  padding: 0 28px 28px;
  font-size: 13px;
}

@media (max-width: 1040px) {
  .workspace,
  .intro,
  .results-grid {
    grid-template-columns: 1fr;
  }

  .control-panel {
    position: static;
  }
}

@media (max-width: 720px) {
  main {
    padding: 16px;
  }

  .workspace,
  .intro,
  .control-panel,
  .result-card {
    width: 100%;
    max-width: 100%;
  }

  .lede {
    font-size: 17px;
    max-width: calc(100vw - 32px);
    word-break: break-word;
    overflow-wrap: break-word;
  }

  .topbar {
    align-items: flex-start;
    flex-direction: column;
    padding: 14px 16px;
  }

  .topbar nav {
    flex-wrap: wrap;
  }

  .panel-heading {
    align-items: stretch;
    flex-direction: column;
    overflow: hidden;
  }

  .preset-row {
    display: flex;
    overflow-x: auto;
    padding-bottom: 4px;
    scroll-snap-type: x proximity;
  }

  .preset-row button {
    flex: 0 0 auto;
    min-width: 0;
    padding: 0 16px;
    scroll-snap-align: start;
  }

  fieldset,
  .metric-tiles,
  .candidate-row,
  .batch-row,
  .formula-grid {
    grid-template-columns: 1fr;
  }

  input {
    min-width: 0;
  }

  h1 {
    font-size: 42px;
  }
}