:root {
  --bg0: #eef3f1;
  --bg1: #f7faf8;
  --ink: #1c2b28;
  --muted: #5a6e68;
  --line: #c9d6d0;
  --accent: #0f6b5c;
  --accent-soft: #d7ebe5;
  --panel: rgba(255, 255, 255, 0.82);
  --shadow: 0 18px 50px rgba(28, 43, 40, 0.08);
  --radius: 14px;
  --font-sans: "IBM Plex Sans", "PingFang SC", "Noto Sans SC", sans-serif;
  --font-serif: "Source Serif 4", "Songti SC", "Noto Serif SC", serif;
  --font-mono: "IBM Plex Mono", "SFMono-Regular", ui-monospace, monospace;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  min-height: 100%;
  color: var(--ink);
  font-family: var(--font-sans);
  background:
    radial-gradient(1000px 500px at 10% -10%, #d9ebe4 0%, transparent 55%),
    radial-gradient(800px 420px at 100% 0%, #e7efe8 0%, transparent 50%),
    linear-gradient(180deg, var(--bg0), var(--bg1) 40%, #e8eeea);
}

body {
  line-height: 1.65;
}

.page {
  width: min(1100px, calc(100% - 2rem));
  margin: 0 auto;
  padding: 1.5rem 0 3rem;
}

.top {
  margin-bottom: 1.25rem;
}

.brand-name {
  margin: 0 0 0.35rem;
  font-size: 0.78rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  font-weight: 600;
}

.top h1 {
  margin: 0;
  font-family: var(--font-serif);
  font-size: clamp(1.8rem, 3vw, 2.4rem);
  font-weight: 600;
  letter-spacing: -0.02em;
}

.tagline {
  margin: 0.45rem 0 0;
  color: var(--muted);
  font-size: 0.98rem;
}

.tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
  margin-bottom: 1rem;
  position: sticky;
  top: 0.6rem;
  z-index: 10;
  padding: 0.45rem;
  background: rgba(247, 250, 248, 0.88);
  backdrop-filter: blur(10px);
  border: 1px solid var(--line);
  border-radius: 999px;
  box-shadow: 0 8px 24px rgba(28, 43, 40, 0.05);
}

.tab {
  appearance: none;
  border: 0;
  background: transparent;
  color: var(--muted);
  font: inherit;
  font-size: 0.92rem;
  font-weight: 500;
  padding: 0.55rem 0.95rem;
  border-radius: 999px;
  cursor: pointer;
  transition: background 0.15s ease, color 0.15s ease;
}

.tab:hover {
  color: var(--ink);
  background: rgba(15, 107, 92, 0.08);
}

.tab[aria-selected="true"] {
  color: #fff;
  background: var(--accent);
}

.panel {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  min-height: 60vh;
  overflow: hidden;
}

.status {
  padding: 0.85rem 1.25rem;
  background: #fff6e8;
  color: #6a4b16;
  border-bottom: 1px solid #efd9b0;
  font-size: 0.92rem;
}

.content {
  padding: 1.5rem 1.6rem 2.2rem;
}

.prose > :first-child {
  margin-top: 0;
}

.prose h1,
.prose h2,
.prose h3 {
  font-family: var(--font-serif);
  font-weight: 600;
  letter-spacing: -0.015em;
  line-height: 1.25;
}

.prose h1 {
  font-size: 1.85rem;
  margin: 0 0 1rem;
}

.prose h2 {
  font-size: 1.4rem;
  margin: 2rem 0 0.8rem;
  padding-top: 0.4rem;
  border-top: 1px solid var(--line);
}

.prose h2:first-of-type {
  border-top: 0;
  padding-top: 0;
}

.prose h3 {
  font-size: 1.12rem;
  margin: 1.4rem 0 0.55rem;
}

.prose p,
.prose li {
  color: #243632;
}

.prose a {
  color: var(--accent);
  text-underline-offset: 0.15em;
}

.prose blockquote {
  margin: 1rem 0;
  padding: 0.2rem 0 0.2rem 1rem;
  border-left: 3px solid var(--accent);
  color: var(--muted);
}

.prose code {
  font-family: var(--font-mono);
  font-size: 0.9em;
  background: var(--accent-soft);
  padding: 0.1em 0.35em;
  border-radius: 4px;
}

.prose pre {
  overflow: auto;
  padding: 0.95rem 1rem;
  border-radius: 10px;
  background: #17302b;
  color: #e7f2ee;
  border: 1px solid #23453e;
}

.prose pre code {
  background: transparent;
  color: inherit;
  padding: 0;
}

.prose table {
  width: 100%;
  border-collapse: collapse;
  margin: 1rem 0 1.4rem;
  font-size: 0.95rem;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 10px;
}

.prose th,
.prose td {
  border-bottom: 1px solid var(--line);
  padding: 0.65rem 0.75rem;
  text-align: left;
  vertical-align: top;
}

.prose th {
  background: #eef6f3;
  font-weight: 600;
}

.prose tr:last-child td {
  border-bottom: 0;
}

.prose hr {
  border: 0;
  border-top: 1px solid var(--line);
  margin: 1.8rem 0;
}

.mermaid-wrap {
  margin: 1.1rem 0 1.5rem;
  padding: 1rem;
  overflow-x: auto;
  background: linear-gradient(180deg, #f4faf7, #eef5f1);
  border: 1px solid var(--line);
  border-radius: 12px;
}

.mermaid-wrap .mermaid {
  display: flex;
  justify-content: center;
}

.mermaid-wrap svg {
  max-width: 100%;
  height: auto;
}

.foot {
  margin-top: 1rem;
  color: var(--muted);
  font-size: 0.85rem;
  text-align: center;
}

@media (max-width: 720px) {
  .page {
    width: min(100% - 1rem, 1100px);
  }

  .tabs {
    border-radius: 16px;
  }

  .tab {
    font-size: 0.85rem;
    padding: 0.5rem 0.75rem;
  }

  .content {
    padding: 1.1rem 1rem 1.6rem;
  }

  .prose table {
    display: block;
    overflow-x: auto;
  }
}