:root {
  --bg0: #fbf8f2; /* book white */
  --bg1: #fbf8f2;
  --ink0: #161514;
  --ink1: #2b2926;
  --muted: #5b564f;
  --paper: #ffffff;
  --paper-strong: #ffffff;
  --line: rgba(22, 21, 20, 0.12);
  --line-hover: rgba(22, 21, 20, 0.22);
  --shadow: rgba(22, 21, 20, 0.06);
  --topbar-bg: rgba(251, 248, 242, 0.92);

  --code-bg: rgba(22, 21, 20, 0.06);
  --code-border: rgba(22, 21, 20, 0.10);
  --pre-bg: rgba(22, 21, 20, 0.06);
  --pre-border: rgba(22, 21, 20, 0.12);
  --diagram-bg: rgba(22, 21, 20, 0.02);
  --diagram-border: rgba(22, 21, 20, 0.10);

  --tag-note: rgba(22, 21, 20, 0.20);
  --tag-open: rgba(22, 21, 20, 0.28);
  --tag-bach: rgba(11, 110, 107, 0.35);
  --tag-synth: rgba(181, 82, 46, 0.35);

  --accent: #0b5a57;
  --accent2: #7a3d28;
  --accent-hover-bg: rgba(11, 110, 107, 0.08);
  --accent-hover-border: rgba(11, 110, 107, 0.18);
  --current-bg: rgba(181, 82, 46, 0.10);
  --current-border: rgba(181, 82, 46, 0.22);
  --cite-border: rgba(11, 110, 107, 0.25);
  --cite-hover-bg: rgba(11, 110, 107, 0.10);

  --radius: 14px;
  --radius-sm: 10px;

  --serif: ui-serif, Georgia, "Times New Roman", Times, serif;
  --mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", monospace;
}

:root[data-theme="dark"] {
  --bg0: #0f1112;
  --bg1: #0f1112;
  --ink0: #ece7dd;
  --ink1: #d7d1c7;
  --muted: #a7a095;
  --paper: #16191a;
  --paper-strong: #1b1f20;
  --line: rgba(236, 231, 221, 0.14);
  --line-hover: rgba(236, 231, 221, 0.26);
  --shadow: rgba(0, 0, 0, 0.45);
  --topbar-bg: rgba(15, 17, 18, 0.92);

  --code-bg: rgba(236, 231, 221, 0.08);
  --code-border: rgba(236, 231, 221, 0.12);
  --pre-bg: rgba(236, 231, 221, 0.08);
  --pre-border: rgba(236, 231, 221, 0.14);
  --diagram-bg: rgba(236, 231, 221, 0.04);
  --diagram-border: rgba(236, 231, 221, 0.12);

  --tag-note: rgba(236, 231, 221, 0.22);
  --tag-open: rgba(236, 231, 221, 0.30);
  --tag-bach: rgba(86, 214, 204, 0.38);
  --tag-synth: rgba(226, 154, 122, 0.38);

  --accent: #56d6cc;
  --accent2: #e29a7a;
  --accent-hover-bg: rgba(86, 214, 204, 0.14);
  --accent-hover-border: rgba(86, 214, 204, 0.28);
  --current-bg: rgba(226, 154, 122, 0.18);
  --current-border: rgba(226, 154, 122, 0.34);
  --cite-border: rgba(86, 214, 204, 0.34);
  --cite-hover-bg: rgba(86, 214, 204, 0.14);
}

/* Default to system theme when possible (and fall back to light if unsupported).
   A user-selected light theme should override system-dark. */
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg0: #0f1112;
    --bg1: #0f1112;
    --ink0: #ece7dd;
    --ink1: #d7d1c7;
    --muted: #a7a095;
    --paper: #16191a;
    --paper-strong: #1b1f20;
    --line: rgba(236, 231, 221, 0.14);
    --line-hover: rgba(236, 231, 221, 0.26);
    --shadow: rgba(0, 0, 0, 0.45);
    --topbar-bg: rgba(15, 17, 18, 0.92);

    --code-bg: rgba(236, 231, 221, 0.08);
    --code-border: rgba(236, 231, 221, 0.12);
    --pre-bg: rgba(236, 231, 221, 0.08);
    --pre-border: rgba(236, 231, 221, 0.14);
    --diagram-bg: rgba(236, 231, 221, 0.04);
    --diagram-border: rgba(236, 231, 221, 0.12);

    --tag-note: rgba(236, 231, 221, 0.22);
    --tag-open: rgba(236, 231, 221, 0.30);
    --tag-bach: rgba(86, 214, 204, 0.38);
    --tag-synth: rgba(226, 154, 122, 0.38);

    --accent: #56d6cc;
    --accent2: #e29a7a;
    --accent-hover-bg: rgba(86, 214, 204, 0.14);
    --accent-hover-border: rgba(86, 214, 204, 0.28);
    --current-bg: rgba(226, 154, 122, 0.18);
    --current-border: rgba(226, 154, 122, 0.34);
    --cite-border: rgba(86, 214, 204, 0.34);
    --cite-hover-bg: rgba(86, 214, 204, 0.14);
  }
}

* { box-sizing: border-box; }
html {
  height: 100%;
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
}
body { height: 100%; }
body {
  margin: 0;
  color: var(--ink0);
  font-family: var(--serif);
  font-size: 17px;
  line-height: 1.65;
  background: var(--bg0);
}

.skip-link {
  position: absolute;
  left: -999px;
  top: 8px;
  background: var(--paper-strong);
  border: 1px solid var(--line);
  padding: 8px 10px;
  border-radius: 8px;
  color: var(--ink0);
}
.skip-link:focus { left: 10px; z-index: 10; }

.topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  gap: 16px;
  align-items: center;
  justify-content: space-between;
  padding: 14px 16px;
  border-bottom: 1px solid var(--line);
  background: var(--topbar-bg);
  backdrop-filter: blur(6px);
}
.topbar__brand { min-width: 220px; }
.brand {
  font-family: var(--mono);
  font-weight: 600;
  letter-spacing: -0.02em;
  font-size: 18px;
  color: var(--ink0);
  text-decoration: none;
}
.tagline {
  font-size: 12px;
  color: var(--muted);
  margin-top: 2px;
}
.tagline a {
  color: inherit;
  text-decoration: underline;
  text-decoration-color: var(--line-hover);
  text-underline-offset: 2px;
}
.tagline a:hover {
  color: var(--ink0);
  text-decoration-color: var(--accent);
}

.topbar__tools {
  display: flex;
  gap: 12px;
  align-items: center;
}

.btn {
  font-family: var(--mono);
  font-weight: 500;
  font-size: 12px;
  padding: 8px 10px;
  border-radius: 10px;
  border: 1px solid var(--line);
  background: var(--paper-strong);
  color: var(--ink1);
  cursor: pointer;
}
.btn--icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 8px;
  width: 36px;
  height: 36px;
}
.btn:hover { border-color: var(--line-hover); }
.btn:active { transform: translateY(1px); }

.theme-toggle__icon {
  width: 16px;
  height: 16px;
  stroke: currentColor;
  fill: none;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
}

:root[data-theme="light"] .theme-toggle__icon--sun { display: none; }
:root[data-theme="dark"] .theme-toggle__icon--moon { display: none; }

.layout {
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 18px;
  max-width: 1180px;
  margin: 0 auto;
  padding: 18px 16px 40px;
}

.sidenav {
  align-self: start;
  position: sticky;
  top: 72px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--paper);
  box-shadow: none;
  padding: 14px 12px;
  max-height: calc(100vh - 90px);
  overflow: auto;
}
.navgroup { margin-bottom: 12px; }
.navtitle {
  font-family: var(--mono);
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--muted);
  margin: 8px 8px 6px;
}
.nav a {
  display: block;
  padding: 8px 10px;
  border-radius: 10px;
  color: var(--ink1);
  text-decoration: none;
  border: 1px solid transparent;
}
.nav a:hover {
  background: var(--accent-hover-bg);
  border-color: var(--accent-hover-border);
}
.nav a[aria-current="page"] {
  background: var(--current-bg);
  border-color: var(--current-border);
}

.navdetails {
  margin: 4px 0 0;
}
.navsummary {
  list-style: none;
  display: block;
  padding: 8px 10px;
  border-radius: 10px;
  color: var(--ink1);
  text-decoration: none;
  border: 1px solid transparent;
  cursor: pointer;
  user-select: none;
}
.navsummary::-webkit-details-marker { display: none; }
.navsummary:hover {
  background: var(--accent-hover-bg);
  border-color: var(--accent-hover-border);
}
.navsummary::after {
  content: "▸";
  float: right;
  opacity: 0.55;
}
.navdetails[open] .navsummary::after { content: "▾"; }
.navdetails > a { padding-left: 22px; }
.navdetails[open] { padding-bottom: 2px; }

.main { min-width: 0; }
.paper {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: none;
  padding: 22px 22px;
  animation: none;
}

h1, h2, h3, h4 {
  line-height: 1.15;
  margin: 18px 0 10px;
}
h1 {
  font-size: 30px;
  letter-spacing: -0.02em;
  margin-top: 6px;
}
h2 {
  font-size: 20px;
  margin-top: 22px;
}
h3 { font-size: 16px; margin-top: 18px; }

p { margin: 10px 0; }
ul, ol { margin: 10px 0 10px 20px; }
li { margin: 6px 0; }
hr {
  border: 0;
  border-top: 1px solid var(--line);
  margin: 18px 0;
}
code {
  font-family: var(--mono);
  font-size: 0.92em;
  background: var(--code-bg);
  border: 1px solid var(--code-border);
  padding: 0 6px;
  border-radius: 8px;
}
pre {
  background: var(--pre-bg);
  border: 1px solid var(--pre-border);
  border-radius: 12px;
  padding: 12px 12px;
  overflow: auto;
}
pre code { background: transparent; border: 0; padding: 0; }

.diagram {
  border: 1px solid var(--diagram-border);
  border-radius: 12px;
  padding: 12px;
  overflow: auto;
  background: var(--diagram-bg);
}
.diagram svg {
  display: block;
  max-width: 100%;
  height: auto;
}

.cite {
  display: inline-block;
  font-family: var(--mono);
  font-size: 11px;
  color: var(--accent);
  text-decoration: none;
  border: 1px solid var(--cite-border);
  padding: 2px 6px;
  border-radius: 999px;
  vertical-align: baseline;
  white-space: nowrap;
  max-width: min(42ch, 60vw);
  overflow: hidden;
  text-overflow: ellipsis;
}
.cite:hover {
  background: var(--cite-hover-bg);
}
.cite_time {
  font-family: var(--mono);
  font-size: 11px;
  color: var(--muted);
  white-space: nowrap;
}

.blk {
  position: relative;
  padding-left: 0;
  border-left: 0;
}
.pill {
  display: none;
  position: absolute;
  left: -10px;
  top: 8px;
  transform: translateX(-100%);
  font-family: var(--mono);
  font-size: 10px;
  font-weight: 600;
  letter-spacing: 0.06em;
  padding: 3px 8px;
  border-radius: 999px;
  border: 1px solid var(--line);
  background: var(--paper-strong);
}
.show-tags .pill { display: inline-block; }
.blk[data-tag="BACH"] { }
.blk[data-tag="SYNTH"] { }
.blk[data-tag="NOTE"] { }
.blk[data-tag="OPEN"] { }
.show-tags .blk[data-tag="BACH"] { border-left: 3px solid var(--tag-bach); padding-left: 12px; }
.show-tags .blk[data-tag="SYNTH"] { border-left: 3px solid var(--tag-synth); padding-left: 12px; }
.show-tags .blk[data-tag="NOTE"] { border-left: 3px solid var(--tag-note); padding-left: 12px; }
.show-tags .blk[data-tag="OPEN"] { border-left: 3px solid var(--tag-open); padding-left: 12px; }

.search { position: relative; width: min(520px, 52vw); }
.search__input {
  width: 100%;
  padding: 10px 12px;
  border-radius: 12px;
  border: 1px solid var(--line);
  background: var(--paper-strong);
  font-family: var(--mono);
  font-size: 12px;
  color: var(--ink1);
}
.search__results {
  position: absolute;
  right: 0;
  left: 0;
  top: 44px;
  background: var(--paper-strong);
  border: 1px solid var(--line);
  border-radius: 12px;
  box-shadow: 0 12px 28px var(--shadow);
  padding: 8px;
  max-height: 52vh;
  overflow: auto;
}
.hit {
  display: block;
  padding: 10px 10px;
  border-radius: 10px;
  text-decoration: none;
  color: var(--ink1);
  border: 1px solid transparent;
}
.hit:hover {
  background: var(--accent-hover-bg);
  border-color: var(--accent-hover-border);
}
.hit__title { font-family: var(--mono); font-weight: 600; font-size: 12px; }
.hit__snippet { font-size: 12px; color: var(--muted); margin-top: 2px; }

.footer {
  border-top: 1px solid var(--line);
  background: var(--bg0);
  padding: 18px 16px;
}
.footer__inner {
  max-width: 1180px;
  margin: 0 auto;
  display: flex;
  gap: 14px;
  justify-content: space-between;
  color: var(--muted);
  font-size: 12px;
}
.footer__meta { font-family: var(--mono); }

@media (max-width: 920px) {
  .layout { grid-template-columns: 1fr; }
  .sidenav { position: relative; top: 0; max-height: none; overflow: visible; }
  .search { width: min(680px, 70vw); }
  .paper { padding: 18px 16px; }
  .pill { display: none !important; }
}