:root {
  color-scheme: light;
  --ink: #1c1916;
  --muted: #6f675e;
  --paper: #fff;
  --accent: #c47a2c;
  --line: rgba(28, 25, 22, 0.12);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  background: var(--paper);
  color: var(--ink);
  font-family: "Avenir Next", "Hiragino Sans", "Segoe UI", sans-serif;
}

main {
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 72px 24px 40px;
}

h1 {
  position: fixed;
  top: 22px;
  left: 24px;
  margin: 0;
  color: var(--muted);
  font-size: 0.82rem;
  font-weight: 650;
  letter-spacing: 0.14em;
}

.stage {
  width: min(640px, 100%);
  text-align: center;
}

.phase {
  margin: 0;
  color: var(--muted);
  font-size: 0.95rem;
  letter-spacing: 0.08em;
}

.readout {
  display: flex;
  justify-content: center;
  align-items: flex-end;
  gap: 12px;
  margin: 8px 0 0;
}

.download {
  font-size: clamp(6.5rem, 22vw, 11rem);
  font-weight: 600;
  letter-spacing: -0.07em;
  line-height: 0.85;
  font-variant-numeric: tabular-nums;
}

.download.is-empty {
  color: var(--muted);
  font-size: clamp(2.4rem, 8vw, 3.4rem);
  letter-spacing: 0.04em;
}

.unit {
  margin-bottom: 1.1rem;
  color: var(--accent);
  font-size: 1.35rem;
  font-weight: 650;
}

.caption {
  margin: 18px 0 0;
  color: var(--muted);
  font-size: 0.82rem;
  letter-spacing: 0.16em;
}

.metrics {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
  width: min(460px, 100%);
  margin: 36px auto 0;
  padding-top: 22px;
  border-top: 1px solid var(--line);
}

.metrics dt {
  color: var(--muted);
  font-size: 0.75rem;
  letter-spacing: 0.08em;
}

.metrics dd {
  margin: 6px 0 0;
  font-size: 1.35rem;
  font-variant-numeric: tabular-nums;
  font-weight: 600;
}

.metric-unit {
  color: var(--muted);
  font-size: 0.72rem;
  font-weight: 500;
}

button.start {
  margin-top: 36px;
  border: 1px solid var(--accent);
  border-radius: 999px;
  padding: 12px 28px;
  background: transparent;
  color: var(--ink);
  font: inherit;
  font-weight: 650;
  letter-spacing: 0.06em;
  cursor: pointer;
}

button.start:hover {
  background: rgba(196, 122, 44, 0.1);
}

button.start:disabled {
  border-color: var(--line);
  color: var(--muted);
  background: transparent;
  cursor: progress;
}

.message {
  min-height: 1.4em;
  margin: 16px 0 0;
  color: var(--accent);
}

.message.ok {
  color: #24613a;
}

@media (max-width: 640px) {
  h1 {
    left: 16px;
  }

  .metrics {
    gap: 10px;
  }

  .metrics dd {
    font-size: 1.05rem;
  }
}