:root {
  color-scheme: light;
  --bg: #f3f0ea;
  --paper: #ffffff;
  --ink: #1a1f24;
  --muted: #4f5c66;
  --accent: #08597f;
  --accent-soft: #dcecf4;
  --border: #d8d2c7;
  --ring: #2679a3;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "IBM Plex Sans", "Segoe UI", Tahoma, sans-serif;
  background: radial-gradient(circle at top right, #e4ede7 0%, var(--bg) 50%, #efe9de 100%);
  color: var(--ink);
  line-height: 1.55;
}

.wrap {
  max-width: 1320px;
  margin: 0 auto;
  padding: 2rem 1rem 4rem;
}

header {
  background: linear-gradient(125deg, #112233, #0a5a7f);
  color: #fff;
  border-bottom: 4px solid #e9b949;
}

header .wrap {
  padding: 1.5rem 1rem;
}

nav {
  display: flex;
  gap: 0.8rem;
  flex-wrap: wrap;
  margin-top: 0.7rem;
}

nav a {
  color: #fff;
  text-decoration: none;
  border: 1px solid rgba(255, 255, 255, 0.35);
  border-radius: 999px;
  padding: 0.42rem 0.82rem;
  font-size: 0.9rem;
  line-height: 1.2;
}

nav a:hover,
nav a:focus {
  background: rgba(255, 255, 255, 0.16);
  outline: 2px solid rgba(255, 255, 255, 0.65);
  outline-offset: 2px;
}

.doc-shell {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
  align-items: start;
}

.doc-tools {
  position: static;
  background: var(--paper);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1rem;
  box-shadow: 0 8px 24px rgba(18, 28, 38, 0.08);
}

.doc-tools h2 {
  margin: 0;
  border-top: 0;
  padding-top: 0;
  font-size: 1.05rem;
  font-family: "IBM Plex Sans", "Segoe UI", Tahoma, sans-serif;
}

.tool-hint {
  color: var(--muted);
  font-size: 0.9rem;
  margin: 0.5rem 0 0.8rem;
}

.doc-tools label {
  display: block;
  margin: 0.65rem 0 0.25rem;
  font-size: 0.86rem;
  color: var(--muted);
}

.doc-tools input,
.doc-tools select {
  width: 100%;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.52rem 0.6rem;
  font: inherit;
  background: #fff;
}

.doc-tools input:focus,
.doc-tools select:focus {
  outline: 2px solid var(--ring);
  outline-offset: 1px;
  border-color: var(--ring);
}

#searchResults {
  margin-top: 0.7rem;
  max-height: 48vh;
  overflow-y: auto;
  border-top: 1px dashed var(--border);
  padding-top: 0.65rem;
}

#searchResults a {
  display: block;
  padding: 0.32rem 0.42rem;
  border-radius: 6px;
  text-decoration: none;
}

#searchResults a:hover,
#searchResults a:focus {
  background: var(--accent-soft);
  outline: none;
}

#searchResults small {
  display: block;
  color: var(--muted);
  font-size: 0.76rem;
}

.doc-content {
  background: var(--paper);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 1.4rem 1.3rem;
  box-shadow: 0 14px 30px rgba(18, 28, 38, 0.08);
}

h1, h2, h3 {
  font-family: "IBM Plex Serif", Georgia, serif;
  line-height: 1.25;
}

h1 {
  font-size: 1.95rem;
  margin-top: 0.5rem;
}

h2 {
  margin-top: 2rem;
  border-top: 1px solid var(--border);
  padding-top: 1.2rem;
}

h3 {
  margin-top: 1.3rem;
}

a {
  color: var(--accent);
  text-decoration-thickness: 1px;
  text-underline-offset: 2px;
}

li a {
  display: inline-block;
  padding: 0.18rem 0.06rem;
  line-height: 1.3;
}

ul, ol {
  padding-left: 1.3rem;
}

code, pre {
  font-family: "IBM Plex Mono", "SFMono-Regular", Menlo, monospace;
}

pre {
  padding: 0.7rem;
  border-radius: 8px;
  background: #f4f6f8;
  border: 1px solid #dce2e8;
  overflow-x: auto;
}

.back-to-top {
  position: fixed;
  right: 1rem;
  bottom: 1rem;
  z-index: 10;
  border: 1px solid var(--border);
  background: #fff;
  color: var(--ink);
  border-radius: 999px;
  padding: 0.45rem 0.9rem;
  box-shadow: 0 8px 20px rgba(18, 28, 38, 0.15);
  cursor: pointer;
  display: none;
}

.back-to-top.visible {
  display: inline-block;
}

@media (max-width: 900px) {
  .wrap {
    padding: 1rem 0.7rem 2rem;
  }

  .doc-tools {
    order: -1;
  }

  .doc-content {
    padding: 1rem 0.85rem;
    border-radius: 10px;
  }

  h1 {
    font-size: 1.55rem;
  }
}