:root {
  color-scheme: light;
  font-family: "Segoe UI", "Microsoft YaHei UI", "Microsoft YaHei", sans-serif;
  line-height: 1.65;
  color: #172033;
  background: #f4f1e8;
  --page: #f4f1e8;
  --surface: #fffdf8;
  --surface-strong: #ffffff;
  --text: #172033;
  --muted: #4f5b6b;
  --border: #b8aa8d;
  --accent: #7a2e2e;
  --accent-strong: #5f1f1f;
  --focus: #075985;
  --status: #f5e8c8;
  --shadow: 0 0.45rem 1.4rem rgb(58 42 24 / 12%);
}

* {
  box-sizing: border-box;
}

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

body {
  min-height: 100vh;
  margin: 0;
  background:
    linear-gradient(180deg, rgb(122 46 46 / 8%), transparent 15rem),
    var(--page);
  color: var(--text);
}

main {
  width: min(100% - 2rem, 68rem);
  margin-inline: auto;
  padding-block: clamp(1.5rem, 4vw, 3.5rem);
}

h1,
h2,
legend {
  line-height: 1.35;
}

h1 {
  margin: 0 0 1rem;
  color: var(--accent-strong);
  font-family: "STKaiti", "KaiTi", "Microsoft YaHei UI", sans-serif;
  font-size: clamp(2rem, 5vw, 3.25rem);
  letter-spacing: 0.04em;
}

h2 {
  margin: 0 0 1rem;
  font-size: clamp(1.18rem, 2.5vw, 1.45rem);
}

p {
  max-width: 72ch;
}

#status {
  min-height: 1.8rem;
  margin: 0 0 1.5rem;
  padding: 0.65rem 0.9rem;
  border-inline-start: 0.35rem solid var(--accent);
  border-radius: 0.25rem;
  background: var(--status);
  color: var(--text);
}

#status:empty {
  min-height: 0;
  padding-block: 0;
  border-inline-start-width: 0;
}

.start-controls {
  display: grid;
  gap: 1rem;
  width: min(100%, 32rem);
}

.difficulty-field {
  display: grid;
  gap: 0.45rem;
}

.difficulty-field label {
  font-weight: 700;
}

select {
  width: min(100%, 28rem);
  min-height: 2.75rem;
  padding: 0.55rem 0.7rem;
  border: 2px solid var(--border);
  border-radius: 0.45rem;
  background: var(--surface-strong);
  color: var(--text);
  font: inherit;
}

form {
  display: grid;
  gap: 1.25rem;
}

section {
  padding: clamp(1rem, 3vw, 1.6rem);
  border: 1px solid var(--border);
  border-radius: 0.65rem;
  background: var(--surface);
  box-shadow: var(--shadow);
}

fieldset {
  min-width: 0;
  margin: 0;
  padding: 0;
  border: 0;
}

legend {
  width: 100%;
  margin-bottom: 0.85rem;
  padding: 0;
  font-weight: 650;
}

fieldset > div {
  display: flex;
  align-items: flex-start;
  gap: 0.7rem;
  margin-top: 0.55rem;
  padding: 0.7rem 0.8rem;
  border: 1px solid #d7cebd;
  border-radius: 0.45rem;
  background: var(--surface-strong);
}

input[type="radio"],
input[type="checkbox"] {
  flex: 0 0 auto;
  width: 1.2rem;
  height: 1.2rem;
  margin: 0.2rem 0 0;
  accent-color: var(--accent);
}

label {
  flex: 1;
  min-width: 0;
  cursor: pointer;
  overflow-wrap: anywhere;
}

fieldset > div label {
  display: flex;
  align-items: center;
  min-height: 2.75rem;
}

button {
  min-height: 2.75rem;
  padding: 0.65rem 1.25rem;
  border: 2px solid var(--accent-strong);
  border-radius: 0.45rem;
  background: var(--accent);
  color: #ffffff;
  font: inherit;
  font-weight: 700;
  cursor: pointer;
}

form > button,
#content > button,
.start-controls > button {
  justify-self: start;
  margin-top: 0.25rem;
}

button:disabled {
  cursor: wait;
  opacity: 0.65;
}

:focus-visible {
  outline: 0.22rem solid var(--focus);
  outline-offset: 0.2rem;
}

h1:focus,
h2:focus {
  outline: 0.22rem solid var(--focus);
  outline-offset: 0.3rem;
}

ol {
  margin: 1.5rem 0;
  padding-inline-start: 2rem;
}

li + li {
  margin-top: 1rem;
}

li > section {
  background: var(--surface-strong);
}

strong {
  color: var(--accent-strong);
}

@media (hover: hover) {
  button:not(:disabled):hover {
    background: var(--accent-strong);
  }

  fieldset > div:hover {
    border-color: var(--accent);
  }
}

@media (max-width: 40rem) {
  main {
    width: min(100% - 1rem, 68rem);
    padding-block: 1rem 2rem;
  }

  section {
    padding: 1rem;
    border-radius: 0.4rem;
  }

  fieldset > div {
    padding: 0.7rem 0.65rem;
  }

  button {
    width: 100%;
  }
}

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

@media (forced-colors: active) {
  #status,
  section,
  fieldset > div,
  select,
  button {
    border: 1px solid CanvasText;
    box-shadow: none;
  }

  :focus-visible,
  h1:focus,
  h2:focus {
    outline-color: Highlight;
  }
}