:root {
  --paper: #d7e3ea;
  --ink: #16303a;
  --panel: #f4f8f6;
  --key: #ffffff;
  --key-ink: #16303a;
  --op: #1f6b5a;
  --equals: #24577a;
  --line: #c5d4d0;
  --muted: #5d7478;
  --danger: #8d3030;
}

* {
  box-sizing: border-box;
}

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

body {
  background:
    radial-gradient(circle at 20% 0%, #eef6f4 0%, transparent 42%),
    var(--paper);
  color: var(--ink);
  font-family: "Schibsted Grotesk", "Segoe UI", sans-serif;
}

.bench {
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 24px 16px 40px;
}

h1 {
  margin: 0 0 14px;
  font-size: 1.05rem;
  font-weight: 600;
  letter-spacing: -0.02em;
}

.meter {
  width: min(100%, 340px);
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 18px;
  padding: 18px 16px 16px;
  box-shadow: 0 18px 40px rgba(22, 48, 58, 0.08);
}

.tape {
  min-height: 1.2em;
  margin: 0;
  color: var(--muted);
  font-family: "IBM Plex Mono", ui-monospace, monospace;
  font-size: 0.82rem;
  text-align: right;
}

.readout {
  display: block;
  margin: 4px 0 16px;
  font-family: "IBM Plex Mono", ui-monospace, monospace;
  font-size: clamp(2rem, 8vw, 2.6rem);
  font-weight: 500;
  line-height: 1.15;
  text-align: right;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.readout.error {
  color: var(--danger);
  font-size: 1.35rem;
}

.keypad {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
}

button {
  appearance: none;
  border: 1px solid var(--line);
  background: var(--key);
  color: var(--key-ink);
  border-radius: 12px;
  min-height: 58px;
  font: inherit;
  font-size: 1.2rem;
  font-weight: 600;
  cursor: pointer;
}

button:hover {
  background: #eef5f2;
}

button:focus-visible {
  outline: 2px solid var(--equals);
  outline-offset: 2px;
}

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

.op {
  background: var(--op);
  border-color: var(--op);
  color: #f4fbf8;
}

.op:hover,
.op.active {
  background: #185646;
}

.equals {
  background: var(--equals);
  border-color: var(--equals);
  color: #f4f8fb;
}

.equals:hover {
  background: #1c4662;
}

.zero {
  grid-column: span 2;
}

@media (prefers-reduced-motion: reduce) {
  button:active {
    transform: none;
  }
}