/* The Drill Down — theme-03 data-dashboard */
:root {
  --dd-canvas: #f4f5f7;
  --dd-panel: #ffffff;
  --dd-border: #dfe1e6;
  --dd-border-soft: #e8eaee;
  --dd-ink: #1c1e26;
  --dd-ink-soft: #4b5060;
  --dd-ink-faint: #6e7385;
  --dd-indigo: #4f46e5;
  --dd-indigo-deep: #3f38c9;
  --dd-indigo-tint: #eef0fd;
  --dd-emerald: #059669;
  --dd-emerald-tint: #e8f7f1;
  --dd-amber: #b45309;
  --dd-red: #b91c1c;
  --dd-mono: ui-monospace, "SF Mono", "Cascadia Mono", "Segoe UI Mono", Menlo, Consolas, monospace;
  --dd-sans: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--dd-canvas);
  color: var(--dd-ink);
  font-family: var(--dd-sans);
  font-size: 1.0625rem;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

.dd-skip {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--dd-indigo);
  color: #fff;
  padding: .5rem 1rem;
  z-index: 100;
  border-radius: 0 0 6px 0;
}
.dd-skip:focus { left: 0; }

.dd-wrap { max-width: 62rem; margin: 0 auto; padding: 0 1.25rem; }

/* ---------- header ---------- */
.dd-header {
  background: var(--dd-panel);
  border-bottom: 1px solid var(--dd-border);
}
.dd-header-in {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
  padding-top: .8rem;
  padding-bottom: .8rem;
}
.dd-logo {
  display: inline-flex;
  align-items: center;
  gap: .55rem;
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--dd-ink);
  text-decoration: none;
  letter-spacing: -.01em;
}
.dd-logo svg { display: block; }
.dd-nav { display: flex; gap: .25rem; flex-wrap: wrap; }
.dd-nav a {
  color: var(--dd-ink-soft);
  text-decoration: none;
  font-size: .95rem;
  font-weight: 500;
  padding: .35rem .7rem;
  border-radius: 6px;
}
.dd-nav a:hover, .dd-nav a[aria-current="page"] {
  background: var(--dd-indigo-tint);
  color: var(--dd-indigo-deep);
}

/* ---------- content basics ---------- */
main { display: block; padding: 2rem 0 3.5rem; }
h1 { font-size: 1.9rem; line-height: 1.25; letter-spacing: -.015em; margin: .4rem 0 .6rem; }
h2 { font-size: 1.35rem; letter-spacing: -.01em; margin: 2.2rem 0 .6rem; }
h3 { font-size: 1.1rem; margin: 1.6rem 0 .4rem; }
p, li { max-width: 70ch; }
a { color: var(--dd-indigo-deep); }
a:hover { color: var(--dd-indigo); }
code, .dd-mono { font-family: var(--dd-mono); font-size: .92em; }
code { background: var(--dd-indigo-tint); padding: .1em .35em; border-radius: 4px; }

.dd-crumbs { font-size: .85rem; color: var(--dd-ink-faint); margin: 0 0 .2rem; }
.dd-crumbs a { color: var(--dd-ink-faint); text-decoration: none; }
.dd-crumbs a:hover { color: var(--dd-indigo-deep); text-decoration: underline; }

.dd-lede { font-size: 1.15rem; color: var(--dd-ink-soft); margin-top: 0; }

/* ---------- panels ---------- */
.dd-panel {
  background: var(--dd-panel);
  border: 1px solid var(--dd-border);
  border-radius: 10px;
  padding: 1.4rem;
}

/* ---------- calculator layout ---------- */
.dd-calc {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 1.4rem;
  margin: 1.6rem 0;
}
@media (max-width: 46rem) {
  .dd-calc { grid-template-columns: 1fr; }
}

.dd-inputs { display: flex; flex-direction: column; gap: .9rem; }
.dd-field label {
  display: block;
  font-size: .85rem;
  font-weight: 600;
  color: var(--dd-ink-soft);
  margin-bottom: .25rem;
}
.dd-field .dd-hint {
  display: block;
  font-size: .78rem;
  font-weight: 400;
  color: var(--dd-ink-faint);
  margin-top: .2rem;
}
.dd-field input, .dd-field select {
  width: 100%;
  font-family: var(--dd-mono);
  font-size: 1rem;
  padding: .55rem .7rem;
  border: 1px solid var(--dd-border);
  border-radius: 7px;
  background: #fff;
  color: var(--dd-ink);
}
.dd-field input:focus, .dd-field select:focus {
  outline: 2px solid var(--dd-indigo);
  outline-offset: 1px;
  border-color: var(--dd-indigo);
}
.dd-field-row { display: flex; gap: .9rem; }
.dd-field-row .dd-field { flex: 1; }

/* result card */
.dd-result {
  background: linear-gradient(180deg, #fbfcfe 0%, #f6f8fb 100%);
  border: 1px solid var(--dd-border);
  border-radius: 10px;
  padding: 1.2rem 1.3rem;
  display: flex;
  flex-direction: column;
  gap: .9rem;
}
.dd-result-item .dd-result-label {
  font-size: .78rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: .06em;
  color: var(--dd-ink-faint);
}
.dd-result-item .dd-result-value {
  font-family: var(--dd-mono);
  font-size: 2rem;
  font-weight: 700;
  line-height: 1.15;
  color: var(--dd-emerald);
  overflow-wrap: anywhere;
}
.dd-result-item .dd-result-value.dd-secondary {
  font-size: 1.35rem;
  color: var(--dd-ink);
}
.dd-result-note { font-size: .85rem; color: var(--dd-ink-soft); margin: 0; }
.dd-verdict {
  font-size: .9rem;
  font-weight: 600;
  padding: .35rem .65rem;
  border-radius: 6px;
  display: inline-block;
}
.dd-verdict.good { background: var(--dd-emerald-tint); color: var(--dd-emerald); }
.dd-verdict.mid { background: #fdf3e3; color: var(--dd-amber); }
.dd-verdict.bad { background: #fdeaea; color: var(--dd-red); }

/* show the maths */
.dd-maths {
  border-top: 1px dashed var(--dd-border);
  padding-top: .8rem;
  margin-top: auto;
}
.dd-maths summary {
  cursor: pointer;
  font-size: .9rem;
  font-weight: 600;
  color: var(--dd-indigo-deep);
}
.dd-maths summary:hover { color: var(--dd-indigo); }
.dd-maths-body {
  font-family: var(--dd-mono);
  font-size: .85rem;
  line-height: 1.8;
  color: var(--dd-ink-soft);
  padding: .6rem .1rem 0;
  overflow-x: auto;
}
.dd-maths-body b { color: var(--dd-ink); }

/* link-to-this box */
.dd-cite {
  display: flex;
  gap: .6rem;
  align-items: stretch;
  background: var(--dd-panel);
  border: 1px solid var(--dd-border);
  border-radius: 10px;
  padding: .8rem;
  margin: 1.2rem 0 2rem;
  flex-wrap: wrap;
}
.dd-cite-label {
  flex-basis: 100%;
  font-size: .8rem;
  font-weight: 600;
  color: var(--dd-ink-faint);
  text-transform: uppercase;
  letter-spacing: .05em;
}
.dd-cite input {
  flex: 1;
  min-width: 14rem;
  font-family: var(--dd-mono);
  font-size: .8rem;
  padding: .5rem .6rem;
  border: 1px solid var(--dd-border);
  border-radius: 6px;
  background: var(--dd-canvas);
  color: var(--dd-ink-soft);
}
.dd-copy {
  font: inherit;
  font-size: .85rem;
  font-weight: 600;
  padding: .5rem .9rem;
  border: 1px solid var(--dd-indigo);
  background: var(--dd-indigo);
  color: #fff;
  border-radius: 6px;
  cursor: pointer;
}
.dd-copy:hover { background: var(--dd-indigo-deep); }

/* ---------- formula / example blocks ---------- */
.dd-formula {
  font-family: var(--dd-mono);
  font-size: .95rem;
  background: var(--dd-panel);
  border: 1px solid var(--dd-border);
  border-left: 3px solid var(--dd-indigo);
  border-radius: 8px;
  padding: .8rem 1rem;
  margin: 1rem 0;
  overflow-x: auto;
}
.dd-example {
  background: var(--dd-emerald-tint);
  border: 1px solid #cdeadd;
  border-radius: 8px;
  padding: .9rem 1.1rem;
  margin: 1rem 0;
}
.dd-example p { margin: .3rem 0; }

/* ---------- tables ---------- */
.dd-table-scroll { overflow-x: auto; margin: 1rem 0; }
table.dd-table {
  border-collapse: collapse;
  width: 100%;
  background: var(--dd-panel);
  border: 1px solid var(--dd-border);
  border-radius: 8px;
  font-size: .95rem;
}
.dd-table th, .dd-table td {
  text-align: left;
  padding: .55rem .8rem;
  border-bottom: 1px solid var(--dd-border-soft);
}
.dd-table th {
  font-size: .8rem;
  text-transform: uppercase;
  letter-spacing: .05em;
  color: var(--dd-ink-faint);
  background: #fafbfc;
}
.dd-table td.dd-mono, .dd-table th.dd-mono { font-family: var(--dd-mono); }
.dd-table tr:last-child td { border-bottom: none; }

/* ---------- cards / grids ---------- */
.dd-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(15.5rem, 1fr));
  gap: 1rem;
  margin: 1.2rem 0;
  padding: 0;
  list-style: none;
}
.dd-card {
  background: var(--dd-panel);
  border: 1px solid var(--dd-border);
  border-radius: 10px;
  padding: 1.1rem 1.2rem;
  display: flex;
  flex-direction: column;
  gap: .3rem;
}
.dd-card:hover { border-color: var(--dd-indigo); }
.dd-card a { text-decoration: none; font-weight: 650; color: var(--dd-ink); }
.dd-card a::after { content: ""; position: absolute; inset: 0; }
.dd-card { position: relative; }
.dd-card a:hover { color: var(--dd-indigo-deep); }
.dd-card p { margin: 0; font-size: .88rem; color: var(--dd-ink-soft); }
.dd-card .dd-kw {
  font-family: var(--dd-mono);
  font-size: .75rem;
  color: var(--dd-indigo-deep);
  background: var(--dd-indigo-tint);
  border-radius: 5px;
  padding: .1rem .45rem;
  align-self: flex-start;
  margin-bottom: .2rem;
}

/* related strip */
.dd-related {
  border-top: 1px solid var(--dd-border);
  margin-top: 2.4rem;
  padding-top: 1.2rem;
}
.dd-related ul {
  list-style: none;
  padding: 0;
  margin: .6rem 0 0;
  display: flex;
  flex-wrap: wrap;
  gap: .55rem;
}
.dd-related li a {
  display: inline-block;
  background: var(--dd-panel);
  border: 1px solid var(--dd-border);
  border-radius: 999px;
  padding: .3rem .85rem;
  font-size: .88rem;
  text-decoration: none;
  color: var(--dd-ink-soft);
}
.dd-related li a:hover { border-color: var(--dd-indigo); color: var(--dd-indigo-deep); }

/* glossary hub */
.dd-az-group { margin: 1.6rem 0; }
.dd-az-letter {
  font-family: var(--dd-mono);
  font-size: 1rem;
  color: var(--dd-indigo-deep);
  border-bottom: 1px solid var(--dd-border);
  padding-bottom: .25rem;
  margin: 0 0 .6rem;
}
.dd-az-group ul { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: repeat(auto-fill, minmax(16rem, 1fr)); gap: .35rem .8rem; }
.dd-az-group li a { text-decoration: none; }
.dd-az-group li a:hover { text-decoration: underline; }
.dd-az-group li span { display: block; font-size: .82rem; color: var(--dd-ink-faint); }

/* definition callout on term pages */
.dd-definition {
  background: var(--dd-panel);
  border: 1px solid var(--dd-border);
  border-left: 3px solid var(--dd-emerald);
  border-radius: 8px;
  padding: 1rem 1.2rem;
  margin: 1rem 0 1.4rem;
  font-size: 1.1rem;
}

/* FAQ */
.dd-faq details {
  background: var(--dd-panel);
  border: 1px solid var(--dd-border);
  border-radius: 8px;
  padding: .7rem 1rem;
  margin: .5rem 0;
}
.dd-faq summary { cursor: pointer; font-weight: 600; }
.dd-faq details p { margin: .6rem 0 .2rem; }

/* methodology strip on home */
.dd-strip {
  background: var(--dd-panel);
  border: 1px solid var(--dd-border);
  border-radius: 10px;
  padding: 1.3rem 1.4rem;
  margin: 2rem 0;
}
.dd-strip h2 { margin-top: 0; }
.dd-strip ul { margin: .5rem 0 0; padding-left: 1.2rem; }

/* hero */
.dd-hero { padding: 1.4rem 0 .4rem; }
.dd-hero h1 { font-size: 2.3rem; margin-bottom: .5rem; }
.dd-hero .dd-lede { font-size: 1.2rem; }
.dd-tagline {
  font-family: var(--dd-mono);
  font-size: .85rem;
  color: var(--dd-indigo-deep);
  background: var(--dd-indigo-tint);
  display: inline-block;
  padding: .2rem .7rem;
  border-radius: 999px;
  margin-bottom: .6rem;
}

/* footer */
.dd-footer {
  border-top: 1px solid var(--dd-border);
  background: var(--dd-panel);
  margin-top: 2rem;
  font-size: .88rem;
  color: var(--dd-ink-faint);
}
.dd-footer-in {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
  padding-top: 1.4rem;
  padding-bottom: 1.6rem;
}
.dd-footer a { color: var(--dd-ink-soft); text-decoration: none; }
.dd-footer a:hover { color: var(--dd-indigo-deep); text-decoration: underline; }
.dd-footer nav { display: flex; gap: 1rem; flex-wrap: wrap; }

/* 404 */
.dd-404 { text-align: center; padding: 4rem 1rem; }
.dd-404 .dd-big {
  font-family: var(--dd-mono);
  font-size: 4.5rem;
  font-weight: 700;
  color: var(--dd-indigo);
  line-height: 1;
}