/* ============================================================
   Databases — base styles
   Design goals: calm, readable, book-like. One accent color.
   ============================================================ */

:root {
  --bg:        #fbfbfd;
  --surface:   #ffffff;
  --ink:       #1f2430;
  --ink-soft:  #515a6e;
  --ink-faint: #8a93a6;
  --line:      #e6e8ef;
  --accent:    #4f46e5;   /* indigo */
  --accent-soft:#eef0ff;
  --accent-ink:#3a32c0;
  --teal:      #0d9488;
  --amber:     #b45309;
  --rose:      #be123c;
  --sidebar-w: 290px;
  --measure:   42rem;     /* comfortable reading width */
  --radius:    12px;
  --shadow:    0 1px 2px rgba(20,24,40,.05), 0 8px 24px rgba(20,24,40,.06);
  --font-text: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font-text);
  font-size: 18px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

/* ---------- Sidebar / table of contents ---------- */

#sidebar {
  position: fixed;
  top: 0; left: 0; bottom: 0;
  width: var(--sidebar-w);
  background: var(--surface);
  border-right: 1px solid var(--line);
  overflow-y: auto;
  padding: 22px 0 40px;
  z-index: 40;
}

.brand {
  padding: 6px 24px 18px;
  border-bottom: 1px solid var(--line);
  margin-bottom: 10px;
}
.brand-title {
  font-size: 1.15rem;
  font-weight: 700;
  letter-spacing: -.01em;
}
.brand-subtitle {
  font-size: .8rem;
  color: var(--ink-faint);
  margin-top: 2px;
}

.toc-group-label {
  font-size: .72rem;
  text-transform: uppercase;
  letter-spacing: .08em;
  color: var(--ink-faint);
  font-weight: 700;
  padding: 16px 24px 6px;
}

.toc-link {
  display: block;
  padding: 7px 24px 7px 22px;
  color: var(--ink-soft);
  text-decoration: none;
  font-size: .95rem;
  border-left: 3px solid transparent;
  transition: background .12s, color .12s, border-color .12s;
}
.toc-link:hover { background: var(--accent-soft); color: var(--accent-ink); }
.toc-link.active {
  color: var(--accent-ink);
  border-left-color: var(--accent);
  background: var(--accent-soft);
  font-weight: 600;
}

/* ---------- Content column ---------- */

#content-wrap {
  margin-left: var(--sidebar-w);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  padding: 0 clamp(20px, 6vw, 88px);
}

#content {
  width: 100%;
  max-width: var(--measure);
  margin: 0 auto;
  padding: 56px 0 24px;
  flex: 1 0 auto;
}

#content h1 {
  font-size: 2.1rem;
  line-height: 1.15;
  letter-spacing: -.02em;
  margin: 0 0 .2em;
}
#content h2 {
  font-size: 1.45rem;
  letter-spacing: -.01em;
  margin: 2.2em 0 .5em;
  padding-top: .3em;
}
#content h3 {
  font-size: 1.12rem;
  margin: 1.6em 0 .4em;
  color: var(--ink);
}
#content p { margin: 0 0 1.05em; }
#content ul, #content ol { margin: 0 0 1.1em; padding-left: 1.4em; }
#content li { margin: .3em 0; }

.eyebrow {
  text-transform: uppercase;
  letter-spacing: .1em;
  font-size: .75rem;
  font-weight: 700;
  color: var(--accent);
  margin-bottom: .5em;
}

#content a { color: var(--accent-ink); }

strong { font-weight: 650; }

/* ---------- Callout boxes ---------- */

.callout {
  border: 1px solid var(--line);
  border-left: 4px solid var(--accent);
  background: var(--surface);
  border-radius: var(--radius);
  padding: 16px 20px;
  margin: 1.5em 0;
  box-shadow: var(--shadow);
}
.callout > :first-child { margin-top: 0; }
.callout > :last-child { margin-bottom: 0; }
.callout-label {
  font-size: .72rem;
  text-transform: uppercase;
  letter-spacing: .08em;
  font-weight: 700;
  margin-bottom: .4em;
  color: var(--accent);
}
.callout.ai      { border-left-color: var(--teal); }
.callout.ai      .callout-label { color: var(--teal); }
.callout.note    { border-left-color: var(--amber); }
.callout.note    .callout-label { color: var(--amber); }
.callout.warn    { border-left-color: var(--rose); }
.callout.warn    .callout-label { color: var(--rose); }

/* ---------- Practice problems ---------- */

.problem {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  padding: 16px 20px;
  margin: 1.2em 0;
  box-shadow: var(--shadow);
}
.problem-num {
  font-size: .72rem;
  text-transform: uppercase;
  letter-spacing: .08em;
  font-weight: 700;
  color: var(--ink-faint);
  margin-bottom: .35em;
}
.problem-q > :first-child { margin-top: 0; }
.solution-toggle {
  margin-top: .7em;
  background: var(--accent-soft);
  color: var(--accent-ink);
  border: 1px solid transparent;
  border-radius: 8px;
  padding: 6px 14px;
  font: inherit;
  font-size: .9rem;
  font-weight: 600;
  cursor: pointer;
}
.solution-toggle:hover { background: #e3e6ff; }
.solution {
  margin-top: .9em;
  padding-top: .9em;
  border-top: 1px dashed var(--line);
  display: none;
}
.solution.open { display: block; }
.solution > :first-child { margin-top: 0; }
.solution-label {
  font-size: .72rem;
  text-transform: uppercase;
  letter-spacing: .08em;
  font-weight: 700;
  color: var(--teal);
  margin-bottom: .35em;
}

/* ---------- Interactive widget shell ---------- */

.widget {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  padding: 20px;
  margin: 1.6em 0;
  box-shadow: var(--shadow);
}
.widget-title {
  font-weight: 650;
  font-size: 1rem;
  margin-bottom: .9em;
}
.widget canvas { display: block; width: 100%; }
.controls {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  align-items: center;
  margin-top: 14px;
}
button.btn {
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: 8px;
  padding: 8px 16px;
  font: inherit;
  font-size: .9rem;
  font-weight: 600;
  cursor: pointer;
  transition: filter .12s, transform .04s;
}
button.btn:hover { filter: brightness(1.07); }
button.btn:active { transform: translateY(1px); }
button.btn.ghost {
  background: var(--surface);
  color: var(--accent-ink);
  border: 1px solid var(--line);
}
button.btn.ghost:hover { background: var(--accent-soft); }

.readout {
  display: flex;
  flex-wrap: wrap;
  gap: 18px 28px;
  margin-top: 14px;
  font-variant-numeric: tabular-nums;
}
.readout .stat { display: flex; flex-direction: column; }
.readout .stat .label {
  font-size: .72rem;
  text-transform: uppercase;
  letter-spacing: .06em;
  color: var(--ink-faint);
}
.readout .stat .value {
  font-size: 1.4rem;
  font-weight: 700;
}

/* ---------- Probability scale strip ---------- */

.prob-scale {
  margin: 1.6em 0;
}
.prob-scale .bar {
  height: 16px;
  border-radius: 8px;
  background: linear-gradient(90deg, #e2e8f0, var(--accent));
  position: relative;
}
.prob-scale .ticks {
  display: flex;
  justify-content: space-between;
  font-size: .8rem;
  color: var(--ink-faint);
  margin-top: 8px;
}
.prob-scale .ticks span { width: 33%; }
.prob-scale .ticks span:nth-child(2) { text-align: center; }
.prob-scale .ticks span:nth-child(3) { text-align: right; }

/* ---------- Distribution table (outcome | probability) ---------- */

.dist-table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.4em 0;
  font-variant-numeric: tabular-nums;
  box-shadow: var(--shadow);
  border-radius: var(--radius);
  overflow: hidden;
}
.dist-table th, .dist-table td {
  padding: 9px 16px;
  text-align: left;
  border-bottom: 1px solid var(--line);
}
.dist-table thead th {
  background: var(--accent-soft);
  color: var(--accent-ink);
  font-size: .8rem;
  text-transform: uppercase;
  letter-spacing: .05em;
}
.dist-table td:nth-child(2), .dist-table th:nth-child(2) { text-align: right; }
.dist-table tbody tr:last-child td { border-bottom: none; }
.dist-table tfoot td {
  font-weight: 700;
  border-top: 2px solid var(--line);
  background: var(--bg);
}

/* ---------- Static bar chart (answer keys & read-offs, no JS) ---------- */

.barchart { margin: 1.2em 0; }
.bc-plot {
  display: flex;
  align-items: flex-end;
  gap: 12px;
  height: 160px;
  padding: 0 4px;
  border-bottom: 2px solid var(--ink-soft);
}
.bc-col {
  flex: 1;
  height: 100%;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  align-items: center;
}
.bc-val {
  font-size: .78rem;
  color: var(--ink-soft);
  margin-bottom: 5px;
  font-variant-numeric: tabular-nums;
}
.bc-bar {
  width: 72%;
  background: var(--accent);
  border-radius: 6px 6px 0 0;
  min-height: 2px;
}
.bc-labels { display: flex; gap: 12px; padding: 6px 4px 0; }
.bc-labels span { flex: 1; text-align: center; font-weight: 650; color: var(--ink-soft); }
.barchart.teal .bc-bar { background: var(--teal); }
.barchart .bc-caption { font-size: .82rem; color: var(--ink-faint); margin-top: .5em; text-align: center; }

/* ---------- Schematic flow diagram (hand-drawn, not real Langflow) ---------- */

.flow-wrap { margin: 1.5em 0; }
.flowsvg {
  display: block;
  width: 100%;
  height: auto;
  max-width: 580px;
  margin: 0 auto;
}
.flowsvg text { font-family: var(--font-text); }

/* ---------- Interactive lab checklist ---------- */

.checklist { list-style: none; padding-left: 0; margin: 1.1em 0; }
.checklist li { display: flex; align-items: flex-start; gap: 10px; margin: .5em 0; }
.checklist input[type="checkbox"] {
  width: 18px; height: 18px;
  margin-top: 4px;
  accent-color: var(--accent);
  flex: none;
  cursor: pointer;
}
.checklist label { cursor: pointer; }

/* ---------- Numbered step list (labs) ---------- */

.steps { counter-reset: step; list-style: none; padding-left: 0; margin: 1.1em 0; }
.steps > li {
  position: relative;
  padding-left: 44px;
  margin: .85em 0;
  min-height: 30px;
}
.steps > li::before {
  counter-increment: step;
  content: counter(step);
  position: absolute;
  left: 0; top: 0;
  width: 30px; height: 30px;
  border-radius: 50%;
  background: var(--accent-soft);
  color: var(--accent-ink);
  font-weight: 700;
  font-size: .9rem;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* ---------- Slider rows (distribution builder) ---------- */

.slider-grid { display: grid; gap: 10px; margin-top: 6px; }
.slider-row {
  display: grid;
  grid-template-columns: 2.2em 1fr 3em;
  align-items: center;
  gap: 12px;
}
.slider-row .slabel { font-weight: 650; color: var(--ink-soft); }
.slider-row input[type="range"] { width: 100%; accent-color: var(--accent); }
.slider-row .sval {
  text-align: right;
  font-variant-numeric: tabular-nums;
  color: var(--ink);
  font-weight: 600;
}
.value.ok  { color: var(--teal); }
.value.bad { color: var(--amber); }

/* ---------- File uploader (results analysis) ---------- */

.uploader { display: flex; flex-wrap: wrap; gap: 10px; align-items: center; }
.filebtn {
  display: inline-block;
  background: var(--accent);
  color: #fff;
  border-radius: 8px;
  padding: 8px 16px;
  font-size: .9rem;
  font-weight: 600;
  cursor: pointer;
  transition: filter .12s;
}
.filebtn:hover { filter: brightness(1.07); }
.tr-meta { font-size: .9rem; color: var(--ink-faint); margin: .9em 0 0; }
.colpick { display: flex; align-items: center; gap: 8px; margin-top: 12px; font-size: .9rem; }
.colpick select {
  font: inherit;
  font-size: .9rem;
  padding: 4px 8px;
  border-radius: 6px;
  border: 1px solid var(--line);
  background: var(--surface);
}
.freq-empty { color: var(--ink-faint); text-align: center; padding: 18px 0; }

/* ---------- Pager & footer ---------- */

#pager {
  max-width: var(--measure);
  margin: 0 auto;
  width: 100%;
  display: flex;
  justify-content: space-between;
  gap: 12px;
  padding: 28px 0 8px;
  border-top: 1px solid var(--line);
}
.pager-btn {
  flex: 1;
  text-decoration: none;
  color: var(--ink-soft);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 12px 16px;
  background: var(--surface);
  transition: border-color .12s, color .12s;
}
.pager-btn:hover { border-color: var(--accent); color: var(--accent-ink); }
.pager-btn .dir { font-size: .72rem; text-transform: uppercase; letter-spacing: .07em; color: var(--ink-faint); }
.pager-btn .ttl { font-weight: 600; }
.pager-btn.next { text-align: right; }
.pager-btn.disabled { visibility: hidden; }

#page-footer {
  max-width: var(--measure);
  margin: 0 auto;
  width: 100%;
  color: var(--ink-faint);
  font-size: .85rem;
  padding: 24px 0 56px;
}

/* ---------- Mobile ---------- */

#menu-toggle {
  display: none;
  position: fixed;
  top: 14px; left: 14px;
  z-index: 60;
  width: 42px; height: 42px;
  border-radius: 10px;
  border: 1px solid var(--line);
  background: var(--surface);
  font-size: 1.2rem;
  cursor: pointer;
  box-shadow: var(--shadow);
}
#backdrop {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(20,24,40,.35);
  z-index: 35;
}

@media (max-width: 860px) {
  body { font-size: 17px; }
  #menu-toggle { display: block; }
  #sidebar {
    transform: translateX(-100%);
    transition: transform .22s ease;
    box-shadow: var(--shadow);
  }
  #sidebar.open { transform: translateX(0); }
  #backdrop.show { display: block; }
  #content-wrap { margin-left: 0; padding: 0 20px; }
  #content { padding-top: 72px; }
}

/* ---- embeddings section: word chips + raw vector reveal ---- */
.emb-chips { display: flex; flex-wrap: wrap; gap: 8px; }
.emb-chip {
  font: inherit; font-size: .92rem; cursor: pointer;
  padding: 6px 14px; border-radius: 999px;
  border: 1px solid var(--line); background: var(--surface); color: var(--ink-soft);
  transition: background .12s, color .12s, border-color .12s;
}
.emb-chip:hover { border-color: var(--accent); color: var(--accent-ink); }
.emb-chip.on { background: var(--accent); border-color: var(--accent); color: #fff; }
.emb-vec { margin-top: 14px; border: 1px solid var(--line); border-radius: 10px; overflow: hidden; }
.emb-vec-head {
  padding: 9px 12px; background: var(--accent-soft); color: var(--accent-ink);
  font-size: .9rem; font-weight: 600; border-bottom: 1px solid var(--line);
}
.emb-vec-nums {
  padding: 12px; max-height: 168px; overflow: auto;
  font-family: var(--font-mono); font-size: .76rem; line-height: 1.7;
  color: var(--ink-soft); word-break: break-word; background: var(--surface);
}

/* ---------- Databases course additions ---------- */
.callout.sec     { border-left-color: var(--rose); }
.callout.sec     .callout-label { color: var(--rose); }

#content code {
  font-family: var(--font-mono);
  font-size: .88em;
  background: var(--accent-soft);
  color: var(--accent-ink);
  padding: .08em .35em;
  border-radius: 5px;
}
#content pre {
  background: #1f2430;
  color: #e6e8ef;
  padding: 1rem 1.2rem;
  border-radius: var(--radius);
  overflow-x: auto;
  font-size: .85rem;
  line-height: 1.55;
}
#content pre code { background: none; color: inherit; padding: 0; font-size: inherit; }
.code-label {
  font-size: .75rem; font-weight: 700; letter-spacing: .06em;
  text-transform: uppercase; color: var(--ink-faint);
  margin: 1.4rem 0 -.6rem;
}

.data-table-wrap { overflow-x: auto; margin: 1.2rem 0; }
.data-table {
  border-collapse: collapse; font-size: .88rem; width: 100%;
  background: var(--surface); border: 1px solid var(--line); border-radius: 8px;
}
.data-table th, .data-table td {
  padding: .45rem .7rem; border-bottom: 1px solid var(--line); text-align: left;
  white-space: nowrap;
}
.data-table thead th { background: var(--accent-soft); color: var(--accent-ink); font-weight: 600; }
.data-table td.bad { background: #fff1f2; color: var(--rose); font-weight: 600; }
.data-table caption { caption-side: bottom; font-size: .8rem; color: var(--ink-faint); padding-top: .4rem; }

/* Lost-update simulator */
.lu-grid { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: .8rem; margin: .8rem 0; }
.lu-box {
  border: 1px solid var(--line); border-radius: 10px; padding: .7rem .8rem;
  background: var(--bg); text-align: center;
}
.lu-box .lu-name { font-size: .78rem; font-weight: 700; text-transform: uppercase; letter-spacing: .05em; color: var(--ink-soft); }
.lu-box .lu-val  { font-family: var(--font-mono); font-size: 1.6rem; font-weight: 700; margin: .2rem 0; }
.lu-box.file { border-color: var(--accent); }
.lu-box .lu-note { font-size: .78rem; color: var(--ink-faint); min-height: 2.4em; }
.lu-controls { display: flex; flex-wrap: wrap; gap: .5rem; margin: .6rem 0; }
.lu-log {
  font-family: var(--font-mono); font-size: .8rem; background: var(--bg);
  border: 1px solid var(--line); border-radius: 8px; padding: .6rem .8rem;
  min-height: 5rem; max-height: 14rem; overflow-y: auto;
}
.lu-log div { margin: .1rem 0; }
.lu-verdict { margin-top: .6rem; font-weight: 600; }
.lu-verdict.bad { color: var(--rose); }
.lu-verdict.good { color: var(--teal); }
.mode-toggle { display: inline-flex; border: 1px solid var(--line); border-radius: 999px; overflow: hidden; margin-bottom: .4rem; }
.mode-toggle button {
  border: 0; background: var(--surface); padding: .35rem .9rem; font: inherit; font-size: .85rem; cursor: pointer; color: var(--ink-soft);
}
.mode-toggle button.on { background: var(--accent); color: #fff; }
@media (max-width: 560px) {
  .lu-grid { grid-template-columns: 1fr; }
}