:root {
  --bg: #f5f8fc;
  --panel: #ffffff;
  --fg: #172033;
  --muted: #64748b;
  --border: #cbd8e8;
  --header: #16233a;
  --header-subtle: #223553;
  --accent: #2f80ed;
  --accent-2: #14b8a6;
  --tag-bg: #e9f3ff;
  --tag-border: #bfdbfe;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background:
    radial-gradient(circle at 20% 0%, rgba(47,128,237,.10), transparent 32%),
    linear-gradient(180deg, #eef5ff 0%, var(--bg) 280px);
  color: var(--fg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans JP", Helvetica, Arial, sans-serif;
  line-height: 1.75;
}

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

a:hover {
  text-decoration: underline;
}

.site-header {
  background: linear-gradient(135deg, var(--header), var(--header-subtle));
  color: #f8fafc;
  border-bottom: 1px solid rgba(255,255,255,.12);
  box-shadow: 0 10px 28px rgba(22,35,58,.16);
}

.site-header-inner {
  max-width: 1180px;
  margin: 0 auto;
  padding: 16px 24px;
  display: flex;
  gap: 18px;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
}

.site-title {
  font-weight: 900;
  color: #f8fafc;
  letter-spacing: .02em;
}

.site-title:hover {
  text-decoration: none;
}

.site-nav {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  font-size: 0.93rem;
}

.site-nav a {
  color: #f8fafc;
  padding: 4px 10px;
  border-radius: 999px;
  background: rgba(255,255,255,.08);
}

.site-nav a:hover {
  background: rgba(255,255,255,.14);
  text-decoration: none;
}

.site-nav a.active {
  background: rgba(47,128,237,.32);
  border: 1px solid rgba(255,255,255,.22);
}

.container {
  max-width: 1180px;
  margin: 0 auto;
  padding: 30px 24px 36px;
}

.page-layout {
  max-width: 1180px;
  margin: 0 auto;
  padding: 30px 24px 36px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) 280px;
  gap: 28px;
}

.main-panel,
.markdown-body {
  min-width: 0;
}

.main-panel,
.markdown-body {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 18px;
  padding: 24px 26px;
  box-shadow: 0 18px 45px rgba(22,35,58,.08);
}

.main-panel h1,
.markdown-body h1 {
  margin: 0 0 22px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--border);
  position: relative;
  font-size: 2rem;
  line-height: 1.3;
}

.main-panel h1::after,
.markdown-body h1::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -2px;
  width: 88px;
  height: 4px;
  border-radius: 999px;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
}

.markdown-body h2 {
  font-size: 1.42rem;
  padding-bottom: .28em;
  border-bottom: 1px solid var(--border);
  margin-top: 32px;
}

.markdown-body h3 {
  margin-top: 24px;
}

.markdown-body code {
  background: rgba(47,128,237,.10);
  padding: .2em .4em;
  border-radius: 6px;
  font-family: ui-monospace, SFMono-Regular, Consolas, "Liberation Mono", Menlo, monospace;
  font-size: 85%;
}

.markdown-body pre {
  background: #f8fbff;
  border: 1px solid var(--border);
  border-radius: 12px;
  overflow-x: auto;
  padding: 16px;
}

.markdown-body pre code {
  background: transparent;
  padding: 0;
}

.markdown-body img {
  max-width: 100%;
  height: auto;
  display: block;
  margin: 16px 0;
  border: 1px solid var(--border);
  border-radius: 12px;
  background: #fff;
}

.markdown-body table {
  width: max-content;
  min-width: 100%;
  border-collapse: separate;
  border-spacing: 0;
  margin: 16px 0;
  border: 1px solid var(--border);
  border-radius: 12px;
  overflow: hidden;
  background: #fff;
}

.markdown-body th,
.markdown-body td {
  border-right: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  padding: 8px 10px;
  vertical-align: top;
  white-space: nowrap;
}

.markdown-body tr > *:last-child {
  border-right: 0;
}

.markdown-body tbody tr:last-child > *,
.markdown-body thead tr:last-child > * {
  border-bottom: 0;
}

.markdown-body th {
  background: #eef5ff;
  color: #1f3b65;
  font-weight: 700;
  text-align: center;
}

.markdown-table-scroll {
  overflow-x: auto;
  margin: 16px 0;
}

.markdown-table-scroll table {
  margin: 0;
}

.math-display, mjx-container[display="true"] {
  overflow-x: auto;
  overflow-y: hidden;
  padding: 0.35em 0;
}


.auto-links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: -8px 0 22px;
}

.auto-links a {
  display: inline-block;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: #f8fbff;
  padding: 4px 12px;
  font-weight: 700;
  box-shadow: 0 4px 12px rgba(22,35,58,.05);
}

.auto-links a:hover {
  text-decoration: none;
  border-color: rgba(47,128,237,.65);
  background: var(--tag-bg);
}

.lead {
  color: var(--muted);
  margin-top: -8px;
}

.portal-section {
  margin-top: 28px;
}

.portal-section h2 {
  font-size: 1.18rem;
  margin: 0 0 12px;
  padding-left: 10px;
  border-left: 4px solid var(--accent);
}

.portal-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(210px, 1fr));
  gap: 14px;
  margin-top: 16px;
}

.portal-card {
  display: block;
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 15px 16px;
  color: var(--fg);
  background: #fff;
  box-shadow: 0 8px 22px rgba(22,35,58,.07);
  transition: transform .12s ease, border-color .12s ease, box-shadow .12s ease;
}

.portal-card:hover {
  transform: translateY(-2px);
  text-decoration: none;
  border-color: rgba(47,128,237,.65);
  box-shadow: 0 12px 28px rgba(47,128,237,.13);
}

.portal-title {
  display: block;
  font-size: 1.08rem;
  font-weight: 800;
}

.portal-count {
  display: block;
  color: var(--muted);
  margin-top: 4px;
  font-size: .92rem;
}

.sidebar {
  display: flex;
  flex-direction: column;
  gap: 16px;
  margin-top: 82px;
}

.side-card {
  border: 1px solid var(--border);
  border-radius: 14px;
  background: #fff;
  padding: 15px 16px;
  box-shadow: 0 8px 22px rgba(22,35,58,.07);
}

.side-card h2 {
  font-size: 1rem;
  margin: 0 0 10px;
  color: #1d4ed8;
}

.side-card p {
  margin: 0;
}

.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.tag {
  display: inline-block;
  border: 1px solid var(--tag-border);
  border-radius: 999px;
  background: var(--tag-bg);
  padding: 2px 10px;
  color: var(--fg);
  font-size: 0.88rem;
}

.tag:hover {
  text-decoration: none;
  border-color: rgba(47,128,237,.75);
}

.tag-note {
  color: var(--muted);
  font-size: 0.9rem;
  margin: 10px 0 0;
}

.side-links {
  padding-left: 1.2em;
  margin: 0;
}

.side-links li {
  margin: 4px 0;
}

.side-nav-group > a,
.side-nav-group > span {
  font-weight: 700;
}

.side-sub-links {
  margin: 4px 0 8px;
  padding-left: 1.1em;
}

.side-sub-links li {
  margin: 2px 0;
}

.external-link-item {
  margin: 6px 0;
}

.table-scroll {
  overflow-x: auto;
}

.contest-table {
  width: 100%;
  min-width: 760px;
  border-collapse: separate;
  border-spacing: 0;
  table-layout: fixed;
  overflow: hidden;
  border: 1px solid var(--border);
  border-radius: 14px;
  background: #fff;
}

.contest-table th,
.contest-table td {
  border-right: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  padding: 8px;
  vertical-align: top;
}

.contest-table tr > *:last-child {
  border-right: 0;
}

.contest-table tbody tr:last-child > * {
  border-bottom: 0;
}

.contest-table thead th {
  background: #eef5ff;
  text-align: center;
  color: #1f3b65;
}

.contest-table tbody th {
  width: 92px;
  background: #f8fbff;
  white-space: nowrap;
}

.contest-table td {
  min-width: 108px;
  height: 58px;
}

.contest-table td.empty {
  color: var(--muted);
  text-align: center;
  vertical-align: middle;
}

.problem-cell {
  display: flex;
  min-width: 0;
  height: 100%;
  flex-direction: column;
  justify-content: flex-start;
  gap: 4px;
  color: var(--fg);
}

.problem-cell:hover {
  color: var(--accent);
}

.problem-code {
  display: block;
  min-width: 0;
  font-size: 0.68rem;
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: 0.02em;
  color: var(--muted);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.problem-title {
  display: block;
  min-width: 0;
  font-size: 0.82rem;
  line-height: 1.2;
  overflow: hidden;
  white-space: nowrap;
  text-overflow: ellipsis;
}

.plain-list {
  padding-left: 1.25em;
}

.plain-list li {
  margin: 6px 0;
}

.tag-section {
  margin-top: 26px;
}

.tag-section h2 {
  font-size: 1.24rem;
  margin-bottom: 10px;
}

.inline-tags {
  margin-left: 8px;
}

.inline-tags .tag {
  font-size: 0.8rem;
  padding: 1px 8px;
}

.group-list {
  display: grid;
  gap: 16px;
}

.index-group {
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 14px 16px;
  background: #fff;
  box-shadow: 0 8px 22px rgba(22,35,58,.05);
}

.index-group h2 {
  margin-top: 0;
  border-left: 4px solid var(--accent);
  padding-left: 10px;
}

.sub-group-list {
  display: grid;
  gap: 12px;
}

.sub-index-group {
  border-top: 1px solid var(--border);
  padding-top: 10px;
}

.sub-index-group:first-child {
  border-top: 0;
  padding-top: 0;
}

.sub-index-group h3 {
  margin: 0 0 8px;
  font-size: 1.05rem;
}

.knowledge-list {
  list-style: none;
  padding-left: 0;
  margin: 0;
}

.knowledge-entry {
  margin: 8px 0;
}

.knowledge-title {
  font-weight: 700;
}

.knowledge-summary {
  color: var(--muted);
  font-size: 0.92rem;
  margin-top: 2px;
}

.config-note {
  color: var(--muted);
  font-size: 0.92rem;
}

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

@media (max-width: 860px) {
  body {
    background: var(--bg);
  }

  .site-header-inner {
    align-items: flex-start;
  }

  .page-layout {
    grid-template-columns: 1fr;
    padding: 18px 14px 28px;
  }

  .container {
    padding: 18px 14px 28px;
  }

  .main-panel,
  .markdown-body {
    padding: 18px 16px;
    border-radius: 14px;
  }

  .main-panel h1,
  .markdown-body h1 {
    font-size: 1.65rem;
  }

  .sidebar {
    margin-top: 0;
    order: initial;
  }

  .contest-table {
    min-width: 720px;
    table-layout: fixed;
  }
}