:root {
  color-scheme: light;
  --bg: #eef2ee;
  --surface: #ffffff;
  --surface-alt: #f7f4ef;
  --ink: #1d2b2a;
  --muted: #64706e;
  --line: #d9dfda;
  --teal: #0f6f64;
  --teal-dark: #0a4c45;
  --rust: #b85f35;
  --gold: #d69b37;
  --shadow: 0 18px 50px rgba(29, 43, 42, 0.12);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-width: 320px;
  min-height: 100vh;
  background:
    linear-gradient(135deg, rgba(15, 111, 100, 0.14), rgba(214, 155, 55, 0.12)),
    var(--bg);
  color: var(--ink);
}

button,
input {
  font: inherit;
}

button {
  cursor: pointer;
}

.app-shell {
  min-height: 100vh;
  padding: 32px 20px;
}

.workspace {
  width: min(1120px, 100%);
  margin: 0 auto;
}

.intro {
  margin-bottom: 22px;
}

.eyebrow {
  margin: 0 0 6px;
  color: var(--rust);
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0;
  text-transform: uppercase;
}

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

h1 {
  margin-bottom: 0;
  font-size: clamp(2rem, 6vw, 4.2rem);
  line-height: 1;
  letter-spacing: 0;
}

h2 {
  margin-bottom: 0;
  font-size: 1.05rem;
  line-height: 1.2;
  letter-spacing: 0;
}

.calculator-grid {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr);
  gap: 18px;
  align-items: stretch;
}

.panel {
  background: var(--surface);
  border: 1px solid rgba(29, 43, 42, 0.12);
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.controls-panel,
.output-panel,
.calculation-panel {
  padding: 22px;
}

.calculation-panel {
  margin-top: 18px;
}

.panel-header {
  display: flex;
  align-items: center;
  min-height: 40px;
  margin-bottom: 18px;
}

.panel-header.split {
  justify-content: space-between;
  gap: 12px;
}

.form-stack {
  display: grid;
  gap: 18px;
}

.field {
  display: grid;
  gap: 8px;
  color: var(--muted);
  font-size: 0.92rem;
  font-weight: 700;
}

.money-input,
.percent-input,
.stepper {
  display: grid;
  align-items: center;
  min-height: 54px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface-alt);
  color: var(--ink);
  overflow: hidden;
}

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

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

.money-input span,
.percent-input span {
  display: grid;
  place-items: center;
  height: 100%;
  min-width: 60px;
  color: var(--teal-dark);
  font-weight: 900;
}

.money-input span {
  border-right: 1px solid var(--line);
}

.percent-input span {
  border-left: 1px solid var(--line);
}

.money-input input,
.percent-input input,
.stepper input {
  width: 100%;
  min-width: 0;
  border: 0;
  outline: 0;
  background: transparent;
  color: var(--ink);
  font-size: 1.35rem;
  font-weight: 800;
}

.money-input input {
  padding: 0 16px;
}

.percent-input input {
  padding: 0 16px;
}

.stepper {
  grid-template-columns: 54px 1fr 54px;
}

.stepper input {
  height: 52px;
  text-align: center;
  border-right: 1px solid var(--line);
  border-left: 1px solid var(--line);
}

.icon-button,
.copy-button {
  display: inline-grid;
  place-items: center;
  border: 0;
  background: transparent;
  color: var(--teal-dark);
}

.icon-button {
  width: 54px;
  height: 52px;
}

.icon-button svg,
.copy-button svg {
  width: 20px;
  height: 20px;
  fill: none;
  stroke: currentColor;
  stroke-linecap: round;
  stroke-linejoin: round;
  stroke-width: 2;
}

.copy-button {
  grid-auto-flow: column;
  gap: 8px;
  min-height: 40px;
  padding: 0 14px;
  border: 1px solid var(--teal);
  border-radius: 8px;
  background: var(--teal);
  color: #fff;
  font-weight: 800;
}

.copy-button:hover,
.copy-button:focus-visible {
  background: var(--teal-dark);
  border-color: var(--teal-dark);
}

.icon-button:hover,
.icon-button:focus-visible {
  background: rgba(15, 111, 100, 0.1);
}

.formula-list {
  display: grid;
  gap: 10px;
  margin: 22px 0 0;
}

.formula-list div {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 12px;
  align-items: center;
  padding: 12px 0;
  border-top: 1px solid var(--line);
}

.formula-list dt,
.formula-list dd {
  margin: 0;
}

.formula-list dt {
  color: var(--muted);
  font-size: 0.9rem;
  font-weight: 700;
}

.formula-list dd {
  color: var(--ink);
  font-weight: 900;
  text-align: right;
}

.message-preview {
  min-height: 304px;
  margin: 0;
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background:
    linear-gradient(90deg, rgba(184, 95, 53, 0.14) 0 6px, transparent 6px),
    #fbfaf7;
  color: var(--ink);
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  font-size: clamp(0.86rem, 2.5vw, 1rem);
  line-height: 1.8;
  white-space: pre-wrap;
  word-break: break-word;
}

.copy-status {
  min-height: 24px;
  margin: 10px 0 0;
  color: var(--teal-dark);
  font-size: 0.9rem;
  font-weight: 700;
}

.calculation-lines {
  display: grid;
  gap: 12px;
}

.calc-line {
  display: grid;
  grid-template-columns: minmax(0, 180px) minmax(0, 1fr);
  gap: 18px;
  align-items: start;
  padding: 14px 0;
  border-top: 1px solid var(--line);
}

.calc-line:first-child {
  border-top: 0;
}

.calc-label {
  color: var(--muted);
  font-size: 0.9rem;
  font-weight: 800;
}

.calc-value {
  color: var(--ink);
  font-weight: 800;
  line-height: 1.5;
}

@media (max-width: 820px) {
  .app-shell {
    padding: 22px 14px;
  }

  .calculator-grid {
    grid-template-columns: 1fr;
  }

  .controls-panel,
  .output-panel,
  .calculation-panel {
    padding: 18px;
  }

  .calc-line {
    grid-template-columns: 1fr;
    gap: 6px;
  }
}

@media (max-width: 460px) {
  .panel-header.split {
    align-items: flex-start;
    flex-direction: column;
  }

  .copy-button {
    width: 100%;
  }

  .formula-list div {
    grid-template-columns: 1fr;
    gap: 4px;
  }

  .formula-list dd {
    text-align: left;
  }
}