:root {
  --bg: #0b0d10;
  --bg-elev: #11151a;
  --bg-card: #141a21;
  --border: #1f2731;
  --border-strong: #2a3441;
  --text: #e6edf3;
  --text-dim: #9aa7b3;
  --text-mute: #6b7785;
  --accent: #5cc8ff;
  --accent-2: #7ee7d3;
  --accent-bg: rgba(92,200,255,0.08);
  --dc: #5cc8ff;
  --dr: #ff9f43;
  --dr-only: #c084fc;
  --shared: #94a3b8;
  --dc-bg: rgba(92,200,255,0.08);
  --dc-border: rgba(92,200,255,0.3);
  --dr-bg: rgba(255,159,67,0.08);
  --dr-border: rgba(255,159,67,0.3);
  --dr-only-bg: rgba(192,132,252,0.08);
  --dr-only-border: rgba(192,132,252,0.3);
  --shared-bg: rgba(148,163,184,0.08);
  --shared-border: rgba(148,163,184,0.3);
  --code-bg: #0f1419;
  --hover-overlay: rgba(255,255,255,0.04);
  --hover-overlay-soft: rgba(255,255,255,0.02);
  --shadow: 0 1px 0 rgba(255,255,255,0.03), 0 12px 30px -12px rgba(0,0,0,0.45);
  --radius: 10px;
  --sidebar-w: 290px;
}

[data-theme="light"] {
  --bg: #f6f8fb;
  --bg-elev: #ffffff;
  --bg-card: #ffffff;
  --border: #e3e7ee;
  --border-strong: #ccd2db;
  --text: #16202b;
  --text-dim: #475263;
  --text-mute: #6b7785;
  --accent: #0a72b3;
  --accent-2: #0a8d72;
  --accent-bg: rgba(10,114,179,0.10);
  --dc: #0a72b3;
  --dr: #b65900;
  --dr-only: #6d39c4;
  --shared: #5a6573;
  --dc-bg: rgba(10,114,179,0.10);
  --dc-border: rgba(10,114,179,0.35);
  --dr-bg: rgba(182,89,0,0.10);
  --dr-border: rgba(182,89,0,0.35);
  --dr-only-bg: rgba(109,57,196,0.10);
  --dr-only-border: rgba(109,57,196,0.35);
  --shared-bg: rgba(90,101,115,0.10);
  --shared-border: rgba(90,101,115,0.35);
  --code-bg: #f1f4f8;
  --hover-overlay: rgba(0,0,0,0.05);
  --hover-overlay-soft: rgba(0,0,0,0.025);
  --shadow: 0 1px 0 rgba(0,0,0,0.02), 0 8px 22px -10px rgba(15,23,42,0.18);
}

/* Sidebar always renders in dark colors, regardless of page theme.
   We re-scope the dark values onto custom properties inside .sidebar
   so all descendants (brand, nav links, theme toggle, footer) inherit
   the dark palette via the same vars they already reference. */
[data-theme="light"] .sidebar {
  --bg-elev: #11151a;
  --bg-card: #141a21;
  --border: #1f2731;
  --border-strong: #2a3441;
  --text: #e6edf3;
  --text-dim: #9aa7b3;
  --text-mute: #6b7785;
  --accent: #5cc8ff;
  --accent-2: #7ee7d3;
  --accent-bg: rgba(92,200,255,0.08);
  --hover-overlay: rgba(255,255,255,0.04);
  --hover-overlay-soft: rgba(255,255,255,0.02);
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  font-size: 17px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", monospace;
  font-size: 0.88em;
  background: var(--code-bg);
  border: 1px solid var(--border);
  padding: 1px 6px;
  border-radius: 5px;
}
pre {
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", monospace;
  font-size: 14px;
  line-height: 1.6;
  background: var(--code-bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.9rem 1.05rem;
  margin: 0.65rem 0;
  overflow-x: auto;
  color: var(--text);
}
pre code {
  background: none;
  border: none;
  padding: 0;
  font-size: inherit;
  border-radius: 0;
  color: inherit;
}
.card .meta-block {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 0.5rem 1rem;
  margin: 0.5rem 0;
}
.card .meta-block li {
  list-style: none;
  padding-left: 0;
}
.card.callout-strength {
  border-left: 3px solid var(--accent-2);
}
.card.callout-weakness {
  border-left: 3px solid var(--dr);
}
.card.callout-improvement {
  border-left: 3px solid var(--dr-only);
}

/* h3 used as a subsection heading inside a card */
.card > h3 {
  font-size: 17px;
  margin: 0 0 0.5rem;
  color: var(--text);
  letter-spacing: -0.005em;
}
.card > h3 + p,
.card > h3 + ul,
.card > h3 + ol,
.card > h3 + pre,
.card > h3 + dl {
  margin-top: 0.4rem;
}
.card > * + h3 {
  margin-top: 1.6rem;
  padding-top: 1.1rem;
  border-top: 1px dashed var(--border);
}

.skip {
  position: absolute;
  left: -9999px;
}
.skip:focus {
  left: 1rem;
  top: 1rem;
  background: var(--bg-elev);
  padding: 0.5rem 0.75rem;
  border: 1px solid var(--border-strong);
  border-radius: 6px;
  z-index: 1000;
}

/* sidebar */
.sidebar {
  position: fixed;
  top: 0;
  left: 0;
  width: var(--sidebar-w);
  height: 100vh;
  background: var(--bg-elev);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  overflow-y: auto;
  z-index: 50;
}

.brand-link {
  display: block;
  color: inherit;
  text-decoration: none;
  border-bottom: 1px solid var(--border);
  transition: background 120ms ease;
}
.brand-link:hover {
  background: var(--hover-overlay-soft);
  text-decoration: none;
}
.brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 1.25rem 1.25rem 1rem;
}
.brand-mark {
  width: 38px;
  height: 38px;
  border-radius: 8px;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: #061018;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 19px;
}
.brand-title {
  font-weight: 600;
  letter-spacing: 0.2px;
  font-size: 16px;
}
.brand-sub {
  font-size: 13px;
  color: var(--text-mute);
  margin-top: 1px;
}

.nav {
  flex: 1;
  padding: 0.5rem 0.5rem 1rem;
}
.nav-group { margin: 0.85rem 0 0.5rem; }
.nav-heading {
  font-size: 12px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-mute);
  padding: 0.25rem 0.75rem 0.3rem;
}
.nav a {
  display: block;
  color: var(--text-dim);
  padding: 0.45rem 0.75rem;
  border-radius: 6px;
  font-size: 15px;
  border-left: 2px solid transparent;
  margin: 1px 0;
  text-decoration: none;
}
.nav a:hover {
  color: var(--text);
  background: var(--hover-overlay);
  text-decoration: none;
}
.nav a.active {
  color: var(--text);
  background: var(--accent-bg);
  border-left-color: var(--accent);
}

/* sub-nav: a clickable header link followed by indented child links */
.nav-group.sub-nav {
  border-top: 1px dashed var(--border);
  padding-top: 0.5rem;
  margin-top: 1rem;
}
.nav a.nav-heading-link {
  display: block;
  padding: 0.4rem 0.75rem 0.45rem;
  font-size: 13px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-dim);
  font-weight: 600;
  border-left: 2px solid transparent;
  margin: 0 0 0.2rem;
  border-radius: 6px;
}
.nav a.nav-heading-link:hover {
  color: var(--text);
  background: var(--hover-overlay);
}
.nav a.nav-heading-link.active {
  color: var(--accent);
  background: var(--accent-bg);
  border-left-color: var(--accent);
}
.nav-group.sub-nav > a:not(.nav-heading-link) {
  padding-left: 1.5rem;
  font-size: 14.5px;
}

.sidebar-foot {
  border-top: 1px solid var(--border);
}
.theme-toggle {
  display: flex;
  align-items: center;
  gap: 0.55rem;
  width: calc(100% - 1.5rem);
  margin: 0.75rem;
  padding: 0.55rem 0.85rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text-dim);
  font-family: inherit;
  font-size: 13.5px;
  cursor: pointer;
  text-align: left;
  transition: color 120ms ease, border-color 120ms ease, background 120ms ease;
}
.theme-toggle:hover {
  color: var(--text);
  border-color: var(--border-strong);
  background: var(--hover-overlay);
}
.theme-toggle:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}
.theme-toggle-icon {
  width: 18px;
  height: 18px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}
.theme-toggle-icon svg {
  width: 18px;
  height: 18px;
}
.theme-toggle-icon .icon-sun { display: none; }
.theme-toggle-icon .icon-moon { display: block; }
[data-theme="light"] .theme-toggle-icon .icon-sun { display: block; }
[data-theme="light"] .theme-toggle-icon .icon-moon { display: none; }
.theme-toggle-label::after {
  content: "Light theme";
}
[data-theme="light"] .theme-toggle-label::after {
  content: "Dark theme";
}

.footer-note {
  padding: 0.65rem 1.25rem 1rem;
  font-size: 13px;
  color: var(--text-mute);
}

/* content */
.content {
  margin-left: var(--sidebar-w);
  padding: 2.5rem 3rem 4rem;
  max-width: 1020px;
}

.page-header { margin-bottom: 2rem; }
.kicker {
  font-size: 13px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--accent-2);
  margin-bottom: 0.6rem;
}
h1 {
  font-size: 36px;
  margin: 0 0 0.6rem;
  line-height: 1.2;
  letter-spacing: -0.01em;
}
.lede {
  color: var(--text-dim);
  max-width: 70ch;
  margin: 0 0 1rem;
  font-size: 17.5px;
}
.legend {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
  margin-top: 0.75rem;
}

h2 {
  font-size: 24px;
  margin: 2.5rem 0 1rem;
  letter-spacing: -0.005em;
}
h3 {
  font-size: 18px;
  margin: 0;
}
.section-rule {
  border-top: 1px solid var(--border);
  padding-top: 1.5rem;
  color: var(--text);
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.15rem 1.3rem;
  margin: 0.75rem 0 1rem;
  box-shadow: var(--shadow);
}
.card-head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 0.4rem;
}
.card p {
  color: var(--text-dim);
  margin: 0.4rem 0 0.6rem;
}

.badges { display: inline-flex; gap: 0.35rem; flex-wrap: wrap; }
.badge {
  display: inline-block;
  font-size: 12px;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  padding: 2px 9px;
  border-radius: 999px;
  border: 1px solid transparent;
  font-weight: 600;
}
.badge.dc {
  color: var(--dc);
  background: var(--dc-bg);
  border-color: var(--dc-border);
}
.badge.dr {
  color: var(--dr);
  background: var(--dr-bg);
  border-color: var(--dr-border);
}
.badge.dr-only {
  color: var(--dr-only);
  background: var(--dr-only-bg);
  border-color: var(--dr-only-border);
}
.badge.shared {
  color: var(--shared);
  background: var(--shared-bg);
  border-color: var(--shared-border);
}

dl.meta {
  display: grid;
  grid-template-columns: 180px 1fr;
  gap: 0.3rem 1rem;
  margin: 0.5rem 0 0;
  padding-top: 0.6rem;
  border-top: 1px dashed var(--border-strong);
  font-size: 14.5px;
}
dl.meta dt {
  color: var(--text-mute);
  font-weight: 500;
}
dl.meta dd {
  color: var(--text);
  margin: 0;
}

table.summary {
  width: 100%;
  border-collapse: collapse;
  margin-top: 0.5rem;
  font-size: 15px;
}
table.summary th,
table.summary td {
  text-align: left;
  padding: 0.6rem 0.8rem;
  border-bottom: 1px solid var(--border);
  vertical-align: top;
}
table.summary th {
  color: var(--text-mute);
  font-weight: 500;
  font-size: 13px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}
table.summary td:first-child {
  width: 30%;
  color: var(--text);
  font-weight: 500;
}

ul { color: var(--text-dim); padding-left: 1.2rem; }
li { margin: 0.3rem 0; }

.page-footer {
  margin-top: 3rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--border);
  color: var(--text-mute);
  font-size: 14px;
}

/* breadcrumb */
.breadcrumb {
  font-size: 14px;
  color: var(--text-mute);
  margin: 0 0 1rem;
  display: flex;
  align-items: center;
  gap: 0.4rem;
  flex-wrap: wrap;
}
.breadcrumb a {
  color: var(--text-dim);
}
.breadcrumb a:hover {
  color: var(--text);
}
.breadcrumb .sep {
  color: var(--text-mute);
  opacity: 0.6;
}
.breadcrumb .current {
  color: var(--text);
}

/* page header on tool pages */
.page-header .badges {
  margin-top: 0.5rem;
}

/* meta grid (used on tool pages for richer Quick facts) */
dl.meta-grid {
  border-top: none;
  padding-top: 0;
  grid-template-columns: 220px 1fr;
  gap: 0.45rem 1rem;
}

/* placeholder cards (dimmer; reader knows it's awaiting content) */
.card.placeholder {
  background: linear-gradient(180deg, rgba(255,255,255,0.01), transparent), var(--bg-card);
  border-style: dashed;
  border-color: var(--border-strong);
}
[data-theme="light"] .card.placeholder {
  background: linear-gradient(180deg, rgba(0,0,0,0.012), transparent), var(--bg-card);
}
.card.placeholder p,
.card.placeholder ul,
.card.placeholder li {
  color: var(--text-mute);
}
.card .muted {
  color: var(--text-mute);
}

/* tool tile grid on the landing page */
.tool-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(290px, 1fr));
  gap: 0.8rem;
  margin: 0.5rem 0 1.5rem;
}
.tool-tile {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  padding: 1.05rem 1.15rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  text-decoration: none;
  color: var(--text);
  transition: border-color 120ms ease, transform 120ms ease, box-shadow 120ms ease;
  box-shadow: var(--shadow);
}
.tool-tile:hover {
  border-color: var(--border-strong);
  transform: translateY(-1px);
  text-decoration: none;
}
.tool-tile h3 {
  font-size: 17px;
  margin: 0;
}
.tool-tile p {
  color: var(--text-dim);
  margin: 0;
  font-size: 14.5px;
  line-height: 1.55;
}
.tool-tile .tile-head {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 0.5rem;
}
.tool-tile .tile-link {
  color: var(--accent);
  font-size: 13.5px;
  margin-top: 0.25rem;
}

/* prev/next page nav at the bottom of each tool page */
.page-nav {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  margin: 2rem 0 0;
  padding-top: 1.25rem;
  border-top: 1px solid var(--border);
}
.page-nav a {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  color: var(--text-dim);
  background: var(--bg-card);
  border: 1px solid var(--border);
  padding: 0.65rem 0.95rem;
  border-radius: 8px;
  text-decoration: none;
  font-size: 15px;
  max-width: 48%;
}
.page-nav a:hover {
  color: var(--text);
  border-color: var(--border-strong);
  text-decoration: none;
}
.page-nav .next {
  margin-left: auto;
  text-align: right;
}

@media (max-width: 900px) {
  :root { --sidebar-w: 250px; }
  .content { padding: 1.85rem 1.5rem 3rem; }
  html, body { font-size: 16.5px; }
}
@media (max-width: 720px) {
  .sidebar {
    position: relative;
    width: 100%;
    height: auto;
    border-right: none;
    border-bottom: 1px solid var(--border);
  }
  .content { margin-left: 0; padding: 1.5rem 1.1rem 3rem; }
  dl.meta { grid-template-columns: 1fr; }
  dl.meta dt { color: var(--text-mute); margin-top: 0.4rem; }
  html, body { font-size: 16px; }
}