:root {
  --color-bg: #f8f9fa;
  --color-surface: #ffffff;
  --color-ink: #282828;
  --color-muted: #6c757d;
  --color-line: #dee2e6;
  --color-accent: #e50914;
  --color-accent-dark: #b5070f;
  --color-accent-soft: #fdeced;
  --color-error: #9a1017;
  --color-error-soft: #fdeced;
  --color-warn: #8a5a00;
  --color-warn-soft: #fff4dc;
  --color-ok: #146c43;
  --color-ok-soft: #e8f3ee;
  --radius: 2px;
  --font-sans: "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Yu Gothic", "Meiryo", system-ui, sans-serif;
  --font-serif: "Noto Serif JP", "Yu Mincho", "游明朝", "Hiragino Mincho ProN", "ヒラギノ明朝 ProN", "MS PMincho", serif;
  --font-brand: "EB Garamond", Garamond, "Times New Roman", "Hiragino Mincho ProN", serif;
  --font-mono: ui-monospace, "SF Mono", "Menlo", "Consolas", monospace;
  color-scheme: light;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--color-bg);
  color: var(--color-ink);
  font-family: var(--font-sans);
  font-size: 15px;
  line-height: 1.7;
}

[hidden] {
  display: none !important;
}

.page {
  padding-inline: 16px;
}

.page__header,
.page__main,
.page__footer {
  max-width: 1040px;
  margin-inline: auto;
}

.page__header {
  padding-block: 40px 20px;
}

.page__eyebrow {
  margin: 0 0 10px;
  color: var(--color-ink);
  font-family: var(--font-brand);
  font-size: 22px;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.page__brand-accent {
  color: var(--color-accent);
}

.page__title {
  margin: 0 0 14px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--color-line);
  font-family: var(--font-serif);
  font-size: 28px;
  font-weight: 500;
  letter-spacing: 0.04em;
  line-height: 1.4;
}

.page__lead {
  max-width: 640px;
  margin: 0;
  color: var(--color-muted);
}

.page__main {
  padding-bottom: 32px;
}

.page__footer {
  padding-block: 24px 40px;
  color: var(--color-muted);
  font-size: 13px;
}

.page__link {
  color: var(--color-accent);
}

.page__link:hover {
  color: var(--color-accent-dark);
}

.tabs {
  display: flex;
  gap: 4px;
  margin-bottom: -1px;
}

.tabs__tab {
  padding: 10px 18px;
  border: 1px solid var(--color-line);
  border-bottom-color: transparent;
  border-radius: var(--radius) var(--radius) 0 0;
  background: transparent;
  color: var(--color-muted);
  font: inherit;
  font-weight: 600;
  cursor: pointer;
}

.tabs__tab--active {
  background: var(--color-surface);
  border-bottom-color: var(--color-surface);
  box-shadow: inset 0 3px 0 var(--color-accent);
  color: var(--color-ink);
}

.panel {
  padding: 24px;
  border: 1px solid var(--color-line);
  border-radius: 0 var(--radius) var(--radius) var(--radius);
  background: var(--color-surface);
}

.panel__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 32px;
}

.form__field {
  margin-bottom: 18px;
}

.form__row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 16px;
}

.form__label {
  display: block;
  margin-bottom: 6px;
  font-size: 13px;
  font-weight: 700;
}

.form__input {
  display: block;
  width: 100%;
  padding: 10px 12px;
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
  background: #fff;
  color: var(--color-ink);
  font: inherit;
}

.form__input:focus {
  outline: 2px solid var(--color-accent);
  outline-offset: 0;
  border-color: var(--color-accent);
}

.form__input--area {
  font-family: var(--font-mono);
  font-size: 13px;
  resize: vertical;
}

.form__hint {
  margin: 6px 0 0;
  color: var(--color-muted);
  font-size: 12px;
  line-height: 1.5;
}

.form__check {
  display: flex;
  align-items: center;
  gap: 8px;
  cursor: pointer;
}

.form__checkbox {
  width: 18px;
  height: 18px;
  accent-color: var(--color-accent);
}

.form__more {
  padding-top: 4px;
  border-top: 1px solid var(--color-line);
}

.form__more-summary {
  padding-block: 12px;
  font-weight: 700;
  cursor: pointer;
}

.result {
  min-width: 0;
  padding: 20px;
  border-radius: var(--radius);
  background: var(--color-bg);
}

.result__title {
  margin: 0 0 12px;
  font-family: var(--font-serif);
  font-size: 17px;
  font-weight: 500;
  letter-spacing: 0.04em;
}

.result__empty {
  color: var(--color-muted);
}

.messages {
  margin: 0 0 12px;
  padding: 0;
  list-style: none;
}

.messages__item {
  margin-bottom: 6px;
  padding: 8px 12px;
  border-radius: var(--radius);
  font-size: 13px;
  line-height: 1.5;
}

.messages__item::before {
  margin-right: 0.6em;
  font-weight: 700;
}

.messages__item--error::before {
  content: "エラー";
}

.messages__item--warn::before {
  content: "注意";
}

.messages__item--ok::before {
  content: "OK";
}

.messages__item--error {
  border-left: 3px solid var(--color-error);
  background: var(--color-error-soft);
  color: var(--color-error);
}

.messages__item--warn {
  border-left: 3px solid var(--color-warn);
  background: var(--color-warn-soft);
  color: var(--color-warn);
}

.messages__item--ok {
  border-left: 3px solid var(--color-ok);
  background: var(--color-ok-soft);
  color: var(--color-ok);
}

.messages__item--info {
  background: #fff;
  border: 1px solid var(--color-line);
  color: var(--color-muted);
}

.output {
  margin-bottom: 16px;
}

.output__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  margin-bottom: 6px;
}

.output__title {
  margin: 0;
  font-size: 13px;
}

.output__code {
  display: block;
  padding: 10px 12px;
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
  background: #fff;
  font-family: var(--font-mono);
  font-size: 12.5px;
  line-height: 1.6;
  overflow-wrap: anywhere;
  user-select: all;
}

.output__note {
  margin: 6px 0 0;
  color: var(--color-muted);
  font-size: 12px;
  line-height: 1.5;
}

.summary {
  display: grid;
  grid-template-columns: max-content 1fr;
  gap: 4px 12px;
  margin: 0 0 16px;
  font-size: 13px;
}

.summary dt {
  color: var(--color-muted);
}

.summary dd {
  margin: 0;
  font-family: var(--font-mono);
  overflow-wrap: anywhere;
}

.button {
  flex-shrink: 0;
  padding: 6px 14px;
  border: 1px solid var(--color-accent);
  border-radius: var(--radius);
  background: var(--color-accent);
  color: #fff;
  font: inherit;
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
}

.button:hover {
  background: var(--color-accent-dark);
}

.button--ghost {
  background: #fff;
  color: var(--color-accent);
}

.button--ghost:hover {
  background: var(--color-accent-soft);
}

.button--done {
  background: var(--color-accent-dark);
}

.rules {
  margin-top: 32px;
}

.rules__title {
  margin: 0 0 12px;
  padding-left: 12px;
  border-left: 3px solid var(--color-accent);
  font-family: var(--font-serif);
  font-size: 19px;
  font-weight: 500;
  letter-spacing: 0.04em;
}

.rules__item {
  margin-bottom: 8px;
  padding: 4px 18px;
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
  background: var(--color-surface);
}

.rules__summary {
  padding-block: 12px;
  font-weight: 700;
  cursor: pointer;
}

.rules__table {
  width: 100%;
  margin-bottom: 12px;
  border-collapse: collapse;
  font-size: 13px;
}

.rules__table th,
.rules__table td {
  padding: 8px 10px;
  border-bottom: 1px solid var(--color-line);
  text-align: left;
  vertical-align: top;
}

.rules__table-wrap {
  overflow-x: auto;
}

.rules__text,
.rules__list {
  margin: 0 0 14px;
  font-size: 13.5px;
}

.rules__list {
  padding-left: 20px;
}

.rules__note {
  color: var(--color-muted);
  font-size: 12px;
}

@media (max-width: 760px) {
  .page__title {
    font-size: 23px;
  }

  .panel {
    padding: 16px;
  }

  .panel__grid,
  .form__row {
    grid-template-columns: minmax(0, 1fr);
    gap: 0;
  }

  .panel__grid {
    gap: 24px;
  }

  .rules__item {
    overflow-x: auto;
  }
}