@import url("https://fonts.googleapis.com/css2?family=IBM+Plex+Mono:wght@400;500;600&display=swap");

/* ------------------------------------------------------------------
   Pandas Quest. Everything is scoped to .quest so it cannot leak into
   the rest of the site, and it overrides a few global rules on purpose
   (button, th, code, img) that would otherwise restyle the guide.
   ------------------------------------------------------------------ */

.quest {
  --paper: #ffffff;
  --bone: #f4f5ef;
  --bone-2: #eaece3;
  --line: #d9ddd0;
  --ink: #1b211d;
  --ink-2: #29312c;
  --text: #2e3430;
  --muted: #667068;
  --bamboo: #3f7d3a;
  --bamboo-d: #2d5f2a;
  --bamboo-soft: #e3efdb;
  --star: #e8a200;
  --star-d: #a56f00;
  --star-soft: #fff4d6;
  --rust: #b3442b;
  --rust-soft: #fbece6;
  --sky: #2b6aa3;
  --sky-soft: #e6f0f8;
  --mono: "IBM Plex Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;

  color: var(--text);
  margin-top: 1rem;
  margin-bottom: 4rem;
  line-height: 1.6;
}

.quest *, .quest *::before, .quest *::after { box-sizing: border-box; }

.quest a { color: var(--sky); text-decoration: underline; text-decoration-color: rgba(43, 106, 163, 0.35); text-underline-offset: 2px; }
.quest a:hover, .quest a:focus { color: var(--ink); text-decoration-color: currentColor; }

.quest :focus-visible { outline: 3px solid var(--sky); outline-offset: 2px; border-radius: 3px; }

.quest h2, .quest h3, .quest h4 { color: var(--ink); line-height: 1.25; }
.quest h2 { font-size: 1.85rem; margin: 0; font-weight: 700; letter-spacing: -0.01em; }
.quest h3 { font-size: 1.2rem; margin: 2.25rem 0 0.4rem; font-weight: 650; }
.quest h4 { font-size: 1rem; margin: 0; font-weight: 650; }

.quest p { margin: 0.7rem 0; }
.quest ul, .quest ol { margin: 0.7rem 0; padding-left: 1.4rem; }
.quest li { margin: 0.3rem 0; }

.q-prose > p, .q-prose > ul, .q-prose > ol, .q-prose > h3,
.q-promise, .q-lede { max-width: 44rem; }

/* ------------------------------ inline code, keys ------------------ */
.quest code {
  font-family: var(--mono);
  font-size: 0.86em;
  padding: 0.08em 0.35em;
  color: var(--ink);
  background: var(--bone-2);
  border-radius: 4px;
}
.quest pre code { padding: 0; background: transparent; border-radius: 0; font-size: 0.86rem; color: inherit; }

.quest kbd {
  font-family: var(--mono);
  font-size: 0.78em;
  padding: 0.05em 0.4em 0.1em;
  color: var(--ink);
  background: var(--paper);
  border: 1px solid var(--line);
  border-bottom-width: 2px;
  border-radius: 4px;
}

/* ------------------------------ sticky progress bar ---------------- */
.q-bar {
  position: sticky;
  top: 0;
  z-index: 30;
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 0.55rem 0;
  background: rgba(255, 255, 255, 0.94);
  -webkit-backdrop-filter: blur(6px);
  backdrop-filter: blur(6px);
  border-bottom: 1px solid var(--line);
  font-size: 0.9rem;
}
.q-bar-stars { font-weight: 650; color: var(--ink); white-space: nowrap; }
.q-bar-stars .q-glyph { color: var(--star); font-size: 1.05em; margin-right: 0.15em; }
.q-bar-rank { color: var(--muted); }
.q-bar-links { margin-left: auto; display: flex; gap: 1rem; }
.q-bar-links a, .q-bar-links button { font-size: 0.85rem; }
.q-bar.is-bump .q-bar-stars { animation: q-bump 0.5s ease; }

/* ------------------------------ hero ------------------------------- */
.q-hero { padding: 1.6rem 0 0.5rem; }
.q-lede { font-size: 1.12rem; line-height: 1.55; margin-top: 0; color: var(--ink); }
.quest .q-rules { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 1.25rem; margin: 1.5rem 0 2rem; padding: 0; list-style: none; max-width: none; }
.quest .q-rules li { margin: 0; padding-top: 0.6rem; border-top: 2px solid var(--ink); font-size: 0.95rem; line-height: 1.5; }
.q-rules strong { display: block; color: var(--ink); margin-bottom: 0.15rem; }

.q-nb { border: 1px solid var(--line); border-radius: 6px; background: var(--paper); overflow: hidden; }
.q-nb-row { display: grid; grid-template-columns: 4.6rem minmax(0, 1fr); }
.q-nb-in { background: var(--bone); border-bottom: 1px solid var(--line); }
.q-nb-label { font-family: var(--mono); font-size: 0.8rem; padding: 0.75rem 0.6rem 0 0; text-align: right; white-space: nowrap; }
.q-nb-in .q-nb-label { color: var(--bamboo-d); }
.q-nb-out .q-nb-label { color: var(--star-d); }
.q-nb-code { font-family: var(--mono); font-size: 0.88rem; padding: 0.7rem 0.9rem; color: var(--ink); }
.q-nb-body { padding: 0.4rem 0.9rem 0.9rem; overflow-x: auto; }
.q-nb-result { font-family: var(--mono); font-size: 0.95rem; padding: 0.7rem 0.9rem; color: var(--ink); font-weight: 600; }

.q-df { width: 100%; margin: 0.4rem 0 0; border-collapse: collapse; font-family: var(--mono); font-size: 0.85rem; border: 0; }
.q-df th, .q-df td { border: 0; padding: 0.38rem 0.9rem; text-align: right; text-transform: none; font-size: inherit; white-space: nowrap; background: transparent !important; }
.q-df thead th { color: var(--ink); font-weight: 600; border-bottom: 1px solid var(--ink); }
.q-df tbody th { font-weight: 600; color: var(--ink); }
.q-df tbody tr:nth-child(odd) th, .q-df tbody tr:nth-child(odd) td { background: var(--bone) !important; }
.q-df td.q-df-name, .q-df thead th.q-df-name { text-align: left; }
.q-df td.q-df-name a { color: var(--ink); text-decoration: none; border-bottom: 1px dotted var(--muted); }
.q-df td.q-df-name a:hover { border-bottom-style: solid; color: var(--bamboo-d); }
.q-df .q-nan { color: #a3aaa2; }
.q-df .q-got { color: var(--star); font-size: 1.15em; line-height: 1; }
.q-df td.is-just-solved .q-got { animation: q-pop 0.6s cubic-bezier(.2, 1.4, .4, 1); }

/* ------------------------------ stages ----------------------------- */
.q-stage { margin-top: 3.5rem; padding-top: 2.2rem; border-top: 2px solid var(--ink); scroll-margin-top: 3.2rem; }
.q-stage-head { display: flex; align-items: flex-start; justify-content: space-between; gap: 1rem; }
.q-stage-num { display: block; color: var(--muted); font-size: 0.9rem; margin-bottom: 0.15rem; }
.q-stage-stars { display: flex; gap: 0.15rem; padding-top: 0.9rem; font-size: 1.5rem; line-height: 1; }
.q-s { color: #cfd3c8; transition: color 0.2s; }
.q-s.is-on { color: var(--star); text-shadow: 0 0 10px rgba(232, 162, 0, 0.45); }
.q-promise { font-size: 1.05rem; color: var(--ink); margin-top: 0.7rem; }
.q-time { color: var(--muted); }

.q-prose { margin-top: 1rem; }

/* ------------------------------ code blocks ------------------------ */
.qcode { margin: 1rem 0; max-width: 52rem; background: var(--ink); border-radius: 6px; overflow: hidden; color: #e8ece6; }
.qcode-bar { display: flex; align-items: center; justify-content: space-between; padding: 0.3rem 0.4rem 0.3rem 0.9rem; background: var(--ink-2); font-family: var(--mono); font-size: 0.74rem; color: #9fb0a3; min-height: 2rem; }
.qcode-name { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.quest .qcopy { font-family: var(--mono); font-size: 0.72rem; line-height: 1; padding: 0.38rem 0.6rem; margin: 0; color: #cdd7cf; background: transparent; border: 1px solid #4b5a4f; border-radius: 4px; cursor: pointer; transition: none; }
.quest .qcopy:hover { background: #3a493e; color: #fff; border-color: #6b7d6f; }
.quest .qcopy.is-done { color: #b8e0a4; border-color: #6e9a5c; }
.qcode pre { margin: 0; padding: 0.85rem 1rem 0.95rem; overflow-x: auto; font-family: var(--mono); font-size: 0.86rem; line-height: 1.55; tab-size: 4; background: transparent; color: inherit; }
.qcode.is-output { background: #f1f2ec; color: var(--ink); border: 1px solid var(--line); }
.qcode.is-output .qcode-bar { background: #e6e8df; color: var(--muted); }

/* syntax colours (pygments class names, no prefix) */
.qcode .c, .qcode .c1, .qcode .cm, .qcode .cs, .qcode .ch { color: #85948a; font-style: italic; }
.qcode .k, .qcode .kn, .qcode .kd, .qcode .kc, .qcode .kr, .qcode .kp, .qcode .ow { color: #f0a86a; }
.qcode .s, .qcode .s1, .qcode .s2, .qcode .sa, .qcode .sb, .qcode .sc, .qcode .sd, .qcode .se, .qcode .si, .qcode .sx { color: #a9d58f; }
.qcode .si, .qcode .se { color: #d7e8a2; }
.qcode .m, .qcode .mi, .qcode .mf, .qcode .mh, .qcode .mb, .qcode .il { color: #8cc3ee; }
.qcode .nb, .qcode .bp { color: #e7d579; }
.qcode .nf, .qcode .fm, .qcode .nc { color: #c8b8f2; }
.qcode .nn, .qcode .ne { color: #e8ece6; }
.qcode .o, .qcode .p { color: #cfd7d1; }
.qcode .nt, .qcode .na { color: #8cc3ee; }
.qcode .err { color: inherit; background: none; }

/* ------------------------------ OS tabs ---------------------------- */
.q-os { margin: 1rem 0; max-width: 52rem; }
.q-os-tabs { display: flex; gap: 0.25rem; margin-bottom: -0.35rem; position: relative; z-index: 1; }
.quest .q-os-tabs button { font: inherit; font-size: 0.85rem; padding: 0.35rem 0.8rem; margin: 0; color: var(--muted); background: var(--bone); border: 1px solid var(--line); border-bottom: 0; border-radius: 6px 6px 0 0; cursor: pointer; transition: none; }
.quest .q-os-tabs button[aria-selected="true"] { color: var(--paper); background: var(--ink); border-color: var(--ink); font-weight: 600; }
.quest .q-os-tabs button:hover { color: var(--ink); background: var(--bone-2); }
.quest .q-os-tabs button[aria-selected="true"]:hover { color: var(--paper); background: var(--ink); }
.q-os .qcode { margin-top: 0; border-top-left-radius: 0; }
.q-os-pane[hidden] { display: none; }

/* tree diagram */
.q-tree { max-width: 52rem; margin: 1rem 0; padding: 1rem 1.2rem; font-family: var(--mono); font-size: 0.85rem; line-height: 1.5; background: var(--bone); border: 1px solid var(--line); border-radius: 6px; overflow-x: auto; color: var(--ink); }
.q-tree code { background: transparent; padding: 0; font-size: inherit; }

/* traceback */
.q-trace { max-width: 52rem; margin: 1rem 0; background: #231a18; border-radius: 6px; overflow-x: auto; }
.q-trace pre { margin: 0; padding: 1rem 1.1rem; font-family: var(--mono); font-size: 0.82rem; line-height: 1.55; color: #e9dcd6; background: transparent; }
.q-trace code { background: transparent; padding: 0; color: inherit; font-size: inherit; }
.q-trace .t-dim { color: #8c7b74; }
.q-trace .t-err { color: #ff8f76; font-weight: 600; }
.q-trace .t-line { color: #f1c27a; }
.q-trace .t-arrow { color: #8fd18a; font-weight: 600; }
.q-trace .t-hot { background: rgba(255, 143, 118, 0.18); outline: 1px solid rgba(255, 143, 118, 0.35); padding: 0 0.2em; }

/* ------------------------------ tables ----------------------------- */
.q-table-wrap { max-width: 52rem; overflow-x: auto; margin: 1rem 0; }
.quest table.q-table { width: 100%; margin: 0; border: 0; border-collapse: collapse; font-size: 0.92rem; }
.quest .q-table th, .quest .q-table td { padding: 0.55rem 0.8rem; border: 0; border-bottom: 1px solid var(--line); text-align: left; vertical-align: top; text-transform: none; font-size: inherit; background: transparent !important; }
.quest .q-table thead th { color: var(--ink); font-weight: 650; border-bottom: 2px solid var(--ink); }
.quest .q-table tbody tr:nth-child(odd) td { background: transparent !important; }
.q-table td:first-child { white-space: nowrap; }
.q-table tr td:first-child code { white-space: nowrap; }

/* ------------------------------ callouts --------------------------- */
.q-callout { max-width: 44rem; margin: 1.3rem 0; padding: 0.75rem 1rem 0.8rem; border-left: 4px solid var(--muted); background: var(--bone); border-radius: 0 6px 6px 0; font-size: 0.96rem; }
.q-callout > :first-child { margin-top: 0.3rem; }
.q-callout > :last-child { margin-bottom: 0; }
.q-callout-title { display: block; color: var(--ink); font-weight: 650; }
.q-callout .qcode { margin: 0.7rem 0 0.2rem; }
.q-callout.is-tip { border-color: var(--sky); background: var(--sky-soft); }
.q-callout.is-trap { border-color: var(--rust); background: var(--rust-soft); }
.q-callout.is-why { border-color: var(--bamboo); background: var(--bamboo-soft); }
.q-callout.is-note { border-color: #8a948b; }

/* ------------------------------ details (hints) -------------------- */
.q-details { max-width: 52rem; margin: 0.8rem 0; }
.q-details > summary { cursor: pointer; font-size: 0.9rem; color: var(--sky); }
.q-details > summary:hover { color: var(--ink); }
.q-details[open] > summary { margin-bottom: 0.5rem; }

/* ------------------------------ puzzles ---------------------------- */
.q-puzzles { margin-top: 2.2rem; display: grid; gap: 1.2rem; max-width: 52rem; }
.q-puzzle { border: 2px solid var(--ink); border-radius: 8px; background: var(--paper); padding: 1rem 1.2rem 1.1rem; }
.q-puzzle[hidden] { display: none; }
.q-puzzle-head { display: flex; align-items: center; gap: 0.5rem; }
.q-star { font-size: 1.5rem; line-height: 1; color: #cfd3c8; display: inline-block; transition: color 0.2s; }
.q-puzzle.is-solved { border-color: var(--bamboo); background: var(--bamboo-soft); }
.q-puzzle.is-solved .q-star { color: var(--star); text-shadow: 0 0 12px rgba(232, 162, 0, 0.5); }
.q-puzzle.is-just-solved .q-star { animation: q-pop 0.7s cubic-bezier(.2, 1.4, .4, 1); }
.q-puzzle.is-part2:not([hidden]) { animation: q-unfold 0.35s ease-out; }
.q-puzzle-body { margin-top: 0.5rem; }
.q-puzzle-body > p:first-child { margin-top: 0; }
.q-puzzle-body .qcode { margin-bottom: 0.4rem; }

.q-answer { display: flex; flex-wrap: wrap; align-items: stretch; gap: 0.5rem; margin-top: 0.9rem; }
.q-prompt { display: flex; align-items: center; font-family: var(--mono); font-size: 0.9rem; color: var(--ink); }
.q-answer input[type="text"] { flex: 1 1 12rem; min-width: 0; font-family: var(--mono); font-size: 0.95rem; padding: 0.55rem 0.7rem; color: var(--ink); background: var(--paper); border: 1.5px solid var(--ink); border-radius: 6px; }
.q-answer textarea { flex: 1 1 100%; order: 2; min-width: 0; font-family: var(--mono); font-size: 0.84rem; line-height: 1.5; padding: 0.6rem 0.7rem; color: var(--ink); background: var(--paper); border: 1.5px solid var(--ink); border-radius: 6px; resize: vertical; }
.q-answer.is-paste .q-prompt { flex: 1 1 100%; }
.q-answer.is-paste .q-check { order: 3; }
.q-answer input:focus, .q-answer textarea:focus { outline: 3px solid rgba(43, 106, 163, 0.35); outline-offset: 0; }

.quest .q-check { font: inherit; font-size: 0.92rem; font-weight: 600; padding: 0.55rem 1.1rem; margin: 0; color: var(--paper); background: var(--ink); border: 1.5px solid var(--ink); border-radius: 6px; cursor: pointer; transition: background-color 0.15s; }
.quest .q-check:hover { background: var(--bamboo-d); border-color: var(--bamboo-d); color: var(--paper); }
.quest .q-check[disabled] { opacity: 0.55; cursor: progress; }
.q-puzzle.is-solved .q-answer input, .q-puzzle.is-solved .q-answer textarea { background: transparent; border-color: var(--bamboo); color: var(--bamboo-d); font-weight: 600; }
.quest .q-puzzle.is-solved .q-check { color: var(--bamboo-d); background: transparent; border-color: var(--bamboo); }
.quest .q-puzzle.is-solved .q-check:hover { color: var(--paper); background: var(--bamboo-d); }

.q-feedback { min-height: 1.5em; margin: 0.6rem 0 0; font-size: 0.95rem; }
.q-feedback.is-ok { color: var(--bamboo-d); font-weight: 600; }
.q-feedback.is-bad { color: var(--rust); }
.q-feedback.is-wait { color: var(--muted); }

.q-choices { display: grid; gap: 0.9rem; margin-top: 0.7rem; }
.q-choice-set { margin: 0; padding: 0; border: 0; min-width: 0; }
.q-choice-set legend { padding: 0; font-weight: 600; color: var(--ink); margin-bottom: 0.3rem; font-size: 0.97rem; }
.q-choice { display: flex; gap: 0.55rem; align-items: flex-start; padding: 0.3rem 0.5rem; margin-left: -0.5rem; border-radius: 5px; cursor: pointer; font-size: 0.95rem; }
.q-choice:hover { background: var(--bone); }
.q-choice input { margin-top: 0.35rem; accent-color: var(--ink); }
.q-answer.is-choices { margin-top: 0.7rem; }
.q-choice-set.is-wrong legend { color: var(--rust); }
.q-choice-set.is-right legend { color: var(--bamboo-d); }

.q-help { margin-top: 0.9rem; }
.q-help .qcode { margin: 0.6rem 0 0; }

/* ------------------------------ practice exercises ----------------- */
.q-practice { margin-top: 2.4rem; max-width: 52rem; }
.q-practice > h3 { margin-top: 0; }
.q-ex { margin: 1.4rem 0; padding: 0.9rem 1.2rem 1rem; border: 1.5px solid var(--line); border-left: 5px solid var(--sky); border-radius: 0 8px 8px 0; background: var(--paper); }
.q-ex.is-done { border-left-color: var(--bamboo); background: var(--bamboo-soft); }
.q-ex-head { display: flex; align-items: baseline; justify-content: space-between; gap: 1rem; }
.q-ex-head h4 { font-size: 1.02rem; }
.q-ex-done { display: inline-flex; align-items: center; gap: 0.4rem; font-size: 0.9rem; color: var(--muted); cursor: pointer; white-space: nowrap; }
.q-ex-done input { accent-color: var(--bamboo-d); width: 1.05rem; height: 1.05rem; }
.q-ex.is-done .q-ex-done { color: var(--bamboo-d); font-weight: 600; }
.q-ex-task { margin-top: 0.3rem; }
.q-ex-task > :first-child { margin-top: 0.3rem; }
.q-ex .qcode { margin: 0.7rem 0; }
.q-ex .q-details { margin: 0.6rem 0 0; }
.q-bar-ex { color: var(--muted); white-space: nowrap; }
@media (max-width: 768px) { .q-bar-ex { display: none; } }

/* ------------------------------ certificate ------------------------ */
.q-cert-wrap { margin-top: 4rem; padding-top: 2.2rem; border-top: 2px solid var(--ink); }
.q-cert-wrap[hidden] { display: none; }
.q-cert-controls { display: flex; flex-wrap: wrap; gap: 0.6rem; align-items: stretch; margin: 1rem 0 1.5rem; max-width: 36rem; }
.q-cert-controls input { flex: 1 1 14rem; font-size: 1rem; padding: 0.55rem 0.7rem; border: 1.5px solid var(--ink); border-radius: 6px; font-family: inherit; color: var(--ink); }
.q-cert { max-width: 40rem; padding: 2.2rem 2rem; text-align: center; border: 3px double var(--ink); border-radius: 4px; background: var(--paper); color: var(--ink); }
.q-cert p { margin: 0.4rem 0; }
.q-cert-stars { font-size: 1.6rem; letter-spacing: 0.15em; color: var(--star); margin: 0.6rem 0; line-height: 1.2; word-break: break-all; }
.q-cert-stars .q-off { color: #d9ddd0; }
.q-cert-name { font-size: 2rem; font-weight: 700; margin: 0.6rem 0; min-height: 2.6rem; border-bottom: 1px solid var(--ink); display: inline-block; padding: 0 1.5rem; }
.q-cert-rank { font-size: 1.1rem; font-weight: 600; }
.q-cert small { color: var(--muted); }

/* ------------------------------ credits ---------------------------- */
.q-credits { max-width: 44rem; margin-top: 3.5rem; padding-top: 1.2rem; border-top: 1px solid var(--line); font-size: 0.88rem; color: var(--muted); }
.q-credits a { color: inherit; }
.quest .q-reset { font: inherit; font-size: 0.85rem; padding: 0; margin: 0; color: var(--muted); background: transparent; border: 0; text-decoration: underline; cursor: pointer; transition: none; }
.quest .q-reset:hover { color: var(--rust); background: transparent; }

/* ------------------------------ motion ----------------------------- */
@keyframes q-pop { 0% { transform: scale(0.4) rotate(-25deg); } 60% { transform: scale(1.35) rotate(8deg); } 100% { transform: scale(1) rotate(0); } }
@keyframes q-bump { 0% { transform: scale(1); } 40% { transform: scale(1.18); } 100% { transform: scale(1); } }
@keyframes q-unfold { from { opacity: 0; transform: translateY(-6px); } to { opacity: 1; transform: none; } }

@media (prefers-reduced-motion: reduce) {
  .quest *, .quest *::before, .quest *::after { animation: none !important; transition: none !important; }
}

/* ------------------------------ small screens ---------------------- */
@media (max-width: 768px) {
  .quest h2 { font-size: 1.5rem; }
  .quest .q-rules { grid-template-columns: 1fr; gap: 0.9rem; }
  .q-nb-row { grid-template-columns: 4rem minmax(0, 1fr); }
  .q-nb-label { font-size: 0.7rem; padding-right: 0.4rem; }
  .q-stage-stars { font-size: 1.25rem; }
  .q-bar { gap: 0.6rem; }
  .q-bar-rank { display: none; }
  .q-df th, .q-df td { padding: 0.35rem 0.55rem; }
  .q-answer input[type="text"] { flex-basis: 100%; }
  .q-prompt { flex: 1 1 100%; }
}

/* ------------------------------ print: certificate only ------------ */
@media print {
  body.q-printing header, body.q-printing footer, body.q-printing .post-header { display: none !important; }
  body.q-printing .quest > *:not(.q-cert-wrap) { display: none !important; }
  body.q-printing .q-cert-wrap { border: 0; margin: 0; padding: 0; }
  body.q-printing .q-cert-wrap > :not(.q-cert) { display: none !important; }
  body.q-printing .q-cert { margin: 3rem auto 0; max-width: none; }
}