:root {
  --bg: #f5f5f5;
  --surface: #ffffff;
  --text: #242424;
  --muted: #777777;
  --line: #e2e2e2;
  --line-strong: #d1d1d1;
  --accent: #4fc45b;
  --accent-hover: #43b64f;
  --max: 1280px;
  --content-max: 1080px;
}
* {
  box-sizing: border-box;
}
html,
body {
  margin: 0;
  min-height: 100%;
}
html {
  scroll-behavior: smooth;
}
body {
  color: var(--text);
  background: var(--bg);
  font-family:
    Arial,
    "Helvetica Neue",
    -apple-system,
    BlinkMacSystemFont,
    "Segoe UI",
    "Hiragino Sans",
    "Hiragino Kaku Gothic ProN",
    "Yu Gothic",
    Meiryo,
    sans-serif;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}
a {
  color: inherit;
}
.page {
  width: min(calc(100% - 40px), var(--max));
  margin: 0 auto;
}
main > .page,
footer > .page {
  max-width: var(--content-max);
}
/* =========================
   HEADER / Shared navigation style
   ========================= */
.site-header {
  font-family: Arial, "Noto Sans JP", "Yu Gothic UI", sans-serif;
  background: #fff;
  border-bottom: 1px solid #d7dde2;
}
.site-header .header-inner {
  height: 46px;
  display: flex;
  align-items: stretch;
  justify-content: space-between;
  width: min(calc(100% - 44px), 1280px);
  margin: 0 auto;
}
.header-brand {
  min-width: 0;
  display: flex;
  align-items: center;
  gap: 12px;
  color: #25313e;
  text-decoration: none;
  white-space: nowrap;
}
.brand-logo {
  display: block;
  width: auto;
  height: 29px;
  max-width: 100%;
  object-fit: contain;
  flex-shrink: 1;
}
.brand-subtitle {
  flex-shrink: 0;
  margin-left: 5px;
  color: #8a99a9;
  font-size: 14px;
  letter-spacing: .3px;
}
.header-nav {
  display: flex;
  align-items: stretch;
  margin-left: auto;
  height: 46px;
  flex-shrink: 0;
}
.header-item {
  position: relative;
  display: inline-flex;
  justify-content: center;
  align-items: center;
  gap: 9px;
  min-width: 120px;
  padding: 0 14px;
  border-left: 1px solid #d5dfe7;
  color: #25313e;
  font-size: 13px;
  font-weight: 700;
  text-decoration: none;
  transition: background-color 150ms ease;
}
.header-item:hover { background: #f7f9fa; }
.header-item::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: transparent;
  transition: background-color 150ms ease;
}
.header-item[aria-current='page']::before { background: #23c653; }
.header-item:focus-visible,
.header-brand:focus-visible {
  outline: 2px solid #4fc45b;
  outline-offset: -3px;
}
.header-item svg {
  width: 19px;
  height: 19px;
  flex: 0 0 auto;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.9;
  stroke-linecap: round;
  stroke-linejoin: round;
}
.header-item.side-notes { min-width: 127px; }
.header-item.dev-tab { min-width: 120px; }
.header-item.srw-link {
  min-width: 133px;
  color: #718092;
  font-weight: 500;
}
.srw-icon {
  display: block;
  width: 19px;
  height: 19px;
  flex: 0 0 19px;
  object-fit: contain;
}
@media (max-width: 900px) {
  .site-header .header-inner { width: min(calc(100% - 28px), 720px); }
  .brand-subtitle { display: none; }
}
@media (max-width: 620px) {
  .site-header .header-inner {
    width: calc(100% - 20px);
  }
  .header-brand { flex: 1 1 auto; min-width: 0; }
  .brand-logo { height: 29px; }
  .header-nav { height: 46px; }
  .header-nav .header-item,
  .header-nav .header-item.side-notes,
  .header-nav .header-item.dev-tab,
  .header-nav .header-item.srw-link {
    width: 46px;
    min-width: 46px;
    padding: 0;
    gap: 0;
    flex: 0 0 46px;
  }
  .header-item svg { width: 22px; height: 22px; }
  .srw-icon { width: 22px; height: 22px; flex-basis: 22px; }
  .header-item .header-label { display: none; }
}

/* =========================
   MAIN
   ========================= */
main {
  padding: 54px 0 72px;
}
/* =========================
   CONTENT PANEL
   ========================= */
.content-panel {
  background: var(--surface);
  border: 1px solid var(--line);
}
/* =========================
   PANEL HEADER
   ========================= */
.panel-header {
  padding: 14px 24px;
  border-bottom: 1px solid var(--line);
  color: var(--accent);
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.10em;
}
/* =========================
   PANEL BODY
   ========================= */
.panel-body {
  padding: clamp(44px, 7vw, 72px);
}
/* =========================
   DESCRIPTION
   ========================= */
.description {
  max-width: 720px;
  margin: 0 auto;
  text-align: center;
  font-size: clamp(1rem, 2vw, 1.08rem);
  font-weight: 500;
  letter-spacing: 0.01em;
}
/* =========================
   STATUS
   ========================= */
.status {
  max-width: 720px;
  margin: 48px auto 0;
  padding-top: 40px;
  border-top: 1px solid var(--line);
}
.status-title {
  margin: 0;
  text-align: center;
  font-size: clamp(1.8rem, 5vw, 2.5rem);
  font-weight: 600;
  letter-spacing: 0.08em;
  line-height: 1.3;
}
.status-text {
  margin: 18px 0 0;
  color: var(--muted);
  text-align: center;
  font-size: 0.94rem;
}
/* =========================
   NOTE LINK
   ========================= */
.note-link-wrap {
  display: flex;
  justify-content: center;
  margin-top: 30px;
}
.note-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  min-width: 190px;
  padding: 12px 20px;
  color: #ffffff;
  background: var(--accent);
  border: 1px solid var(--accent);
  border-radius: 0;
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 700;
  transition:
    background-color 150ms ease,
    border-color 150ms ease;
}
.note-link span {
  transition: transform 150ms ease;
}
.note-link:hover {
  background: var(--accent-hover);
  border-color: var(--accent-hover);
}
.note-link:hover span {
  transform: translateX(3px);
}
.note-link:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 4px;
}
/* =========================
   INFO BAR
   ========================= */
.info-bar {
  display: grid;
  grid-template-columns:
    repeat(4, minmax(0, 1fr));
  margin-top: 36px;
  background: var(--surface);
  border: 1px solid var(--line);
}
.info-item {
  min-width: 0;
  padding: 16px 20px;
  border-right: 1px solid var(--line);
}
.info-item:last-child {
  border-right: 0;
}
.info-label {
  display: block;
  margin-bottom: 3px;
  color: var(--muted);
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.10em;
}
.info-value {
  display: block;
  color: var(--text);
  font-size: 0.86rem;
  font-weight: 600;
}
.info-value a {
  color: inherit;
  text-decoration: none;
  transition: color 150ms ease;
}
.info-value a:hover {
  color: var(--accent);
}
.info-value a:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}
/* =========================
   WRITTEN BY
   ========================= */
.author-value {
  display: flex;
  align-items: center;
  gap: 8px;
}
.author-logo {
  display: block;
  width: 24px;
  height: 24px;
  flex: 0 0 auto;
  object-fit: contain;
}
.author-id {
  white-space: nowrap;
}
/* =========================
   FOOTER
   ========================= */
footer {
  padding: 0 0 36px;
  color: var(--muted);
  font-size: 0.78rem;
  text-align: center;
}
footer a {
  text-decoration: none;
}
footer a:hover {
  color: var(--accent);
}
/* =========================
   TABLET / MOBILE INFO GRID
   ========================= */
@media (max-width: 760px) {
  .info-bar {
    grid-template-columns:
      repeat(2, minmax(0, 1fr));
  }
  .info-item {
    border-right: 1px solid var(--line);
    border-bottom: 1px solid var(--line);
  }
  .info-item:nth-child(2n) {
    border-right: 0;
  }
  .info-item:nth-last-child(-n + 2) {
    border-bottom: 0;
  }
}
/* =========================
   MOBILE
   ========================= */
@media (max-width: 640px) {
  .page {
    width: min(calc(100% - 24px), var(--max));
  }
  main {
    padding: 28px 0 48px;
  }
  .panel-header {
    padding: 12px 18px;
  }
  .panel-body {
    padding: 38px 22px 40px;
  }
  .status {
    margin-top: 38px;
    padding-top: 32px;
  }
  .note-link {
    width: 100%;
  }
  .info-bar {
    margin-top: 20px;
  }
  .info-item {
    padding: 14px 15px;
  }
  .info-label {
    font-size: 0.62rem;
  }
  .info-value {
    font-size: 0.8rem;
  }
  .author-value {
    gap: 7px;
  }
  .author-logo {
    width: 22px;
    height: 22px;
  }
}
/* =========================
   REDUCED MOTION
   ========================= */
@media (prefers-reduced-motion: reduce) {
  * {
    transition: none !important;
  }
}