:root {
  color-scheme: dark;
  --bg: #101114;
  --surface: #1b1e26;
  --border: #313744;
  --text: #f3f4f6;
  --muted: #a1a7b3;
  --link: #c5d4f5;
  --focus: #9db7f5;
  --danger: #f0b4b4;
  --button: #f3f4f6;
  --button-text: #14161c;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  background: var(--bg);
}

body {
  margin: 0;
  min-height: 100vh;
  background: var(--bg);
  color: var(--text);
  font-family: "Avenir Next", "Segoe UI", sans-serif;
  line-height: 1.5;
}

a {
  color: var(--link);
}

a:hover {
  color: var(--text);
}

.topnav {
  display: flex;
  justify-content: flex-end;
  padding: 1.25rem 1.5rem 0;
}

.topnav a {
  font-size: 0.95rem;
  text-decoration: none;
}

.topnav a:hover {
  text-decoration: underline;
}

main {
  width: min(36rem, calc(100% - 2rem));
  margin: 3.5rem auto 1rem;
}

h1 {
  margin: 0 0 0.75rem;
  font-size: clamp(1.85rem, 4vw, 2.5rem);
  font-weight: 600;
  letter-spacing: -0.03em;
  line-height: 1.15;
}

.lede {
  margin: 0 0 2rem;
  color: var(--muted);
}

.field {
  margin-bottom: 1.1rem;
}

label {
  display: block;
  margin-bottom: 0.45rem;
}

input {
  width: 100%;
  padding: 0.8rem 0.9rem;
  border: 1px solid var(--border);
  border-radius: 0.7rem;
  background: var(--surface);
  color: var(--text);
  font: inherit;
  font-variant-numeric: tabular-nums;
}

input:focus {
  outline: 2px solid var(--focus);
  outline-offset: 2px;
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 0.4rem;
}

button {
  padding: 0.7rem 1.15rem;
  border: 1px solid transparent;
  border-radius: 999px;
  background: var(--button);
  color: var(--button-text);
  font: inherit;
  font-size: 0.95rem;
  cursor: pointer;
}

button.secondary {
  background: transparent;
  border-color: var(--border);
  color: var(--text);
}

button:hover {
  filter: brightness(1.08);
}

button:focus-visible,
a:focus-visible {
  outline: 2px solid var(--focus);
  outline-offset: 3px;
}

.error {
  margin: 0.7rem 0 0;
  color: var(--danger);
}

.status,
.caption,
.unit,
.elapsed {
  margin: 0;
}

.status,
.unit,
.caption,
.elapsed {
  color: var(--muted);
}

.elapsed {
  margin-top: 1.25rem;
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.08em;
}

.caption {
  margin-top: 1.5rem;
}

.cost {
  margin: 0.25rem 0 0;
  font-size: clamp(2.8rem, 12vw, 4.6rem);
  font-weight: 600;
  letter-spacing: -0.04em;
  line-height: 1;
  font-variant-numeric: tabular-nums;
}

.share {
  margin: 1.5rem 0 0;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

footer {
  padding: 2.5rem 1rem 3rem;
  color: var(--muted);
  text-align: center;
}

footer a {
  color: var(--muted);
  text-decoration: none;
}

footer a:hover {
  color: var(--text);
  text-decoration: underline;
}

@media (max-width: 640px) {
  main {
    margin-top: 2rem;
  }

  .lede {
    margin-bottom: 1.5rem;
  }
}