:root {
  color-scheme: light;
  --ink: #111827;
  --muted: #4b5563;
  --line: #4b5563;
  --soft-line: #cbd5e1;
  --paper: #ffffff;
  --shade: #f3f4f6;
  --accent: #1d4ed8;
  --accent-soft: #dbeafe;
  --warn: #b91c1c;
  --warn-soft: #fee2e2;
}

* {
  box-sizing: border-box;
}

html {
  background: #e5e7eb;
  color: var(--ink);
  font-family: "BIZ UDPGothic", "Yu Gothic", "Hiragino Kaku Gothic ProN", system-ui, sans-serif;
  line-height: 1.6;
}

body {
  margin: 0 auto;
  max-width: 860px;
  background: var(--paper);
  min-height: 100vh;
}

.checker-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  justify-content: space-between;
  padding: 1rem 1.25rem;
  border-bottom: 1px solid var(--soft-line);
  background: var(--shade);
  font-size: 0.9rem;
}

.checker-nav a {
  color: inherit;
}

main {
  padding: 1.5rem 1.25rem 3rem;
}

.checker-kicker {
  margin: 0 0 0.25rem;
  font-size: 0.75rem;
  letter-spacing: 0.14em;
  color: var(--muted);
  text-transform: uppercase;
}

h1 {
  margin: 0 0 0.75rem;
  font-size: 1.6rem;
  line-height: 1.35;
}

.checker-intro {
  margin: 0 0 1.25rem;
  color: var(--muted);
}

.checker-note {
  margin: 0 0 1.5rem;
  padding: 0.75rem 1rem;
  border: 1px solid var(--soft-line);
  border-left: 4px solid var(--line);
  background: var(--shade);
  font-size: 0.9rem;
}

.checker-section {
  margin: 0 0 1.75rem;
}

.checker-section h2 {
  margin: 0 0 0.6rem;
  font-size: 1.05rem;
  border-bottom: 1px solid var(--soft-line);
  padding-bottom: 0.35rem;
}

.problem-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.problem-tab {
  appearance: none;
  border: 1.5px solid var(--line);
  border-radius: 8px;
  background: var(--paper);
  padding: 0.55rem 0.9rem;
  font: inherit;
  font-weight: 700;
  cursor: pointer;
}

.problem-tab[aria-pressed="true"] {
  background: var(--ink);
  border-color: var(--ink);
  color: var(--paper);
}

.problem-facts {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 0.5rem;
  margin: 1rem 0 0;
}

.problem-facts div {
  border: 1px solid var(--soft-line);
  border-radius: 8px;
  padding: 0.5rem 0.65rem;
  background: var(--shade);
}

.problem-facts dt {
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  color: var(--muted);
}

.problem-facts dd {
  margin: 0.15rem 0 0;
  font-weight: 700;
}

.candidate-form {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  gap: 0.75rem;
}

.candidate-form label {
  display: grid;
  gap: 0.25rem;
  font-size: 0.8rem;
  font-weight: 700;
}

.candidate-form input {
  width: 5.5rem;
  padding: 0.5rem 0.6rem;
  font: inherit;
  font-size: 1.05rem;
  border: 1.5px solid var(--line);
  border-radius: 8px;
  background: var(--paper);
}

.checker-button {
  appearance: none;
  border: none;
  border-radius: 8px;
  background: var(--accent);
  color: #ffffff;
  font: inherit;
  font-weight: 700;
  padding: 0.65rem 1.4rem;
  cursor: pointer;
}

.checker-button:hover {
  background: #1e40af;
}

.checker-button--ghost {
  background: transparent;
  color: var(--muted);
  border: 1.5px solid var(--soft-line);
  font-weight: 400;
}

.checker-button--ghost:hover {
  background: var(--shade);
  color: var(--ink);
}

.score-result {
  margin: 1rem 0 0;
  padding: 1rem 1.25rem;
  border: 1.5px solid var(--line);
  border-radius: 10px;
  background: var(--shade);
  min-height: 4.6rem;
}

.score-result[data-state="ok"] {
  border-color: var(--accent);
  background: var(--accent-soft);
}

.score-result[data-state="error"] {
  border-color: var(--warn);
  background: var(--warn-soft);
}

.score-result__label {
  margin: 0;
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  color: var(--muted);
}

.score-result__value {
  margin: 0.1rem 0 0;
  font-size: 2rem;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
}

.score-result__value small {
  font-size: 0.95rem;
  font-weight: 400;
  color: var(--muted);
}

.query-log {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.92rem;
  font-variant-numeric: tabular-nums;
}

.query-log th,
.query-log td {
  border: 1px solid var(--soft-line);
  padding: 0.4rem 0.6rem;
  text-align: left;
}

.query-log thead th {
  background: var(--shade);
  font-size: 0.8rem;
}

.query-log .is-empty td {
  color: var(--muted);
  text-align: center;
  padding: 0.9rem;
}

.checker-footer-links {
  margin-top: 2.5rem;
  padding-top: 1rem;
  border-top: 1px solid var(--soft-line);
  font-size: 0.9rem;
  color: var(--muted);
}

@media (max-width: 560px) {
  .candidate-form input {
    width: 4.4rem;
  }
}