@import url('https://fonts.googleapis.com/css2?family=Zen+Maru+Gothic:wght@400;500;700&display=swap');

/* ================================================
   Ushino – White & Blue / readable mobile
   ================================================ */

:root {
  color-scheme: light;
  --bg: #ffffff;
  --ink: #374151;
  --muted: #596579;
  --line: #d9e0e7;
  --accent: #245a81;
  --surface: #f5f7f9;
  --link: #245a81;
  --link-hover: #173e5c;
  --table-line: #d9e0e7;
  --shadow: 0 4px 16px rgba(37, 48, 71, .07);
  --r: 18px;
  --content-width: 48em;
}

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

html {
  font-family:
    "Zen Maru Gothic", "Hiragino Maru Gothic ProN",
    "Hiragino Sans", "Yu Gothic", Meiryo,
    system-ui, sans-serif;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--bg);
  font-weight: 400;
  line-height: 2.1;
  letter-spacing: 0.02em;
  overflow-wrap: anywhere;
}

/* link */
a {
  color: var(--link);
  text-decoration: underline;
  text-underline-offset: 0.2em;
}

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

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

/* header / footer */
header,
footer {
  background: var(--surface);
  border-bottom: 1px solid var(--line);
  text-align: center;
  padding: 1rem;
}

header a,
footer a {
  color: var(--accent);
  text-decoration: none;
}

/* layout */
main {
  padding: 2rem 0;
}

.container {
  width: min(100% - 2rem, var(--content-width));
  margin-inline: auto;
}

/* text */
h1,
h2,
h3,
.site-title {
  font-weight: 500;
  line-height: 1.3;
  text-align: center;
  margin-left: auto;
  margin-right: auto;
}

h1,
.site-title {
  font-size: 2rem;
  margin-top: 0;
  margin-bottom: 1rem;
}

h2 {
  max-width: 21em;
  font-size: 2.2rem;
  margin-top: 2.2rem;
  margin-bottom: 1rem;
}

h3 {
  font-size: 1.5rem;
  margin-top: 1.8rem;
  margin-bottom: 0.8rem;
}

p {
  text-align: left;
  font-size: 18px;
  margin: 0 0 1.25em;
}

/* image */
img {
  display: block;
  max-width: 100%;
  height: auto;
  margin-left: auto;
  margin-right: auto;
}

/* button */
.button {
  display: inline-block;
  padding: .6rem 1rem;
  background: var(--accent);
  color: #fff;
  border-radius: 10px;
  text-decoration: none;
  box-shadow: var(--shadow);
}

.button:hover {
  background: var(--link-hover);
  color: #fff;
}

/* list */
ol,
ul {
  text-align: left;
  list-style-position: outside;
  padding-left: 1.75em;
  margin: 0.75em 0 1em;
}

li {
  line-height: 1.8;
  margin: 0.25em 0;
}

ol li::marker {
  font-weight: 600;
  color: var(--accent);
  font-variant-numeric: tabular-nums;
}

ul li::marker {
  color: var(--accent);
}

/* table */
.table-container {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  margin: 1rem 0;
}

table {
  width: 100%;
  max-width: var(--content-width);
  border-collapse: collapse;
  margin: 2rem auto;
  background: var(--bg);
  box-shadow: var(--shadow);
  border: 1px solid var(--table-line);
  border-radius: var(--r);
  overflow: hidden;
}

th,
td {
  padding: 0.8rem 1rem;
  text-align: left;
  vertical-align: top;
  font-size: 16px;
  color: var(--ink);
  border: 1px solid var(--table-line);
}

thead {
  background: #eaf0f5;
  color: var(--ink);
  border-bottom: 2px solid var(--table-line);
}

tbody tr:nth-child(even) {
  background: var(--surface);
}

tbody tr:hover {
  background: #edf3f8;
  transition: background 0.2s ease-in-out;
}

/* mobile */
@media (max-width: 768px) {
  body {
    line-height: 2;
  }

  .container {
    width: min(100% - 2rem, var(--content-width));
  }

  p {
    font-size: 16px;
    margin-bottom: 1.15em;
  }

  h1,
  .site-title {
    font-size: 1.7rem;
  }

  h2 {
    font-size: 1.85rem;
    line-height: 1.4;
    max-width: 11em;
  }

  h3 {
    font-size: 1.3rem;
  }

  th,
  td {
    font-size: 14px;
    padding: 0.7rem 0.8rem;
  }
}

.ref-no {
  font-size: 0.6em;
  vertical-align: baseline;
  margin-left: 0.3em;
}


/* share copy */
.header-inner {
  text-align: center;
}

.site-tagline {
  text-align: center;
  font-size: 0.95rem;
  color: var(--ink);
  margin: 0.2rem 0 0;
  line-height: 1.6;
}

.share-copy-under-header {
  width: min(100% - 2rem, var(--content-width));
  margin: 0.7rem auto 0;
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-start;
  align-items: center;
  gap: 0.6rem;
}

.copy-title-url-button {
  appearance: none;
  border: 1px solid #8c9dae;
  background: transparent;
  color: var(--muted);
  border-radius: 999px;
  padding: 0.25rem 0.75rem;
  font: inherit;
  font-size: 0.78rem;
  line-height: 1.4;
  cursor: pointer;
  transition:
    color 0.2s ease,
    border-color 0.2s ease,
    background 0.2s ease;
}

.copy-title-url-button:hover {
  color: var(--link);
  border-color: var(--link);
  background: #edf3f8;
}

.copy-title-url-button:focus-visible {
  outline: 2px solid var(--link);
  outline-offset: 3px;
}

.copy-title-url-message {
  color: var(--muted);
  font-size: 0.78rem;
  line-height: 1.4;
}

.bi {
  font-weight: bold;
  font-style: italic;
}