:root {
  color-scheme: light;
  --background: #ffffff;
  --text: #171717;
  --muted: #5a5a5a;
  --border: #b9b9b9;
  --button: #171717;
  --focus: #0757c7;
}

* {
  box-sizing: border-box;
}

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

body {
  margin: 0;
  background: var(--background);
  color: var(--text);
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: 1.0625rem;
  line-height: 1.62;
  text-rendering: optimizeLegibility;
}

main {
  inline-size: min(calc(100% - 2rem), 44rem);
  margin-inline: auto;
  padding-block: clamp(2rem, 7vw, 4.5rem) 5rem;
}

p {
  margin-block: 0 1.35rem;
}

a:not(.button) {
  color: inherit;
  text-decoration-thickness: 0.08em;
  text-underline-offset: 0.16em;
}

.action-row {
  margin-block: 1.5rem 1.75rem;
}

.button {
  display: inline-flex;
  min-block-size: 2.875rem;
  align-items: center;
  justify-content: center;
  padding: 0.65rem 1rem;
  border: 2px solid var(--button);
  border-radius: 0.25rem;
  font: inherit;
  font-weight: 650;
  line-height: 1.2;
  text-align: center;
  text-decoration: none;
  cursor: pointer;
}

.button-primary {
  background: var(--button);
  color: var(--background);
}

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

.button:hover {
  filter: brightness(1.18);
}

.button-secondary:hover {
  background: #f1f1f1;
  filter: none;
}

.button:focus-visible,
a:not(.button):focus-visible {
  outline: 3px solid var(--focus);
  outline-offset: 3px;
}

.timer {
  margin-block: 2.25rem;
  padding-block: 1.75rem;
  border-block: 1px solid var(--border);
}

.timer-display {
  display: block;
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: clamp(3.25rem, 15vw, 5.75rem);
  font-variant-numeric: tabular-nums;
  font-weight: 700;
  letter-spacing: -0.06em;
  line-height: 1;
}

.timer-controls {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-block-start: 1.5rem;
}

.timer-status {
  margin-block: 0.75rem 0;
  color: var(--muted);
}

.marking-instructions {
  margin-block: 2.25rem;
}

.marking-instructions > p {
  font-weight: 700;
}

ol {
  margin-block: 0;
  padding-inline-start: 1.6rem;
}

li {
  padding-inline-start: 0.3rem;
}

li + li {
  margin-block-start: 1rem;
}

body.focus-mode main {
  padding-block-start: 1.5rem;
}

body.focus-mode .hide-in-focus {
  display: none;
}

body.focus-mode .timer {
  margin-block-start: 0;
  border-block-start: 0;
}

@media (max-width: 30rem) {
  body {
    font-size: 1rem;
  }

  .timer-controls {
    align-items: stretch;
    flex-direction: column;
  }

  .button {
    inline-size: 100%;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto;
  }
}