:root {
  --bg: #0a0c12;
  --panel: #10141d;
  --panel2: #151b28;
  --border: #232c3e;
  --text: #dde4f0;
  --muted: #7c88a1;
  --accent: #6e8bff;
  --accent2: #41e0c8;
  --red: #ff6b7d;
  --green: #5fdba7;
  --kw: #c792ea;
  --str: #9ece6a;
  --num: #ff9e64;
  --comment: #586075;
  --builtin: #7dcfff;
  --call: #82aaff;
  --op: #8fa3c7;
  --mono: ui-monospace, "SF Mono", SFMono-Regular, Menlo, Consolas, monospace;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html, body { height: 100%; }
body { height: 100dvh; }
body {
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", sans-serif;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

/* ---------- header ---------- */
header {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 24px;
  padding: 10px 20px;
  border-bottom: 1px solid var(--border);
  background: var(--panel);
  flex: 0 0 auto;
}
.brand { display: inline-flex; align-items: center; gap: 9px; font-size: 18px; font-weight: 700; letter-spacing: -0.2px; color: var(--text); text-decoration: none; }
.brand .mark { width: 32px; height: 32px; flex: none; }
.ver {
  font-size: 11px; color: var(--muted); font-weight: 500;
  border: 1px solid var(--border); border-radius: 999px; padding: 2px 8px;
  vertical-align: 2px; margin-left: 4px;
}
header nav { display: flex; gap: 4px; }
.tab {
  background: none; border: 1px solid transparent; color: var(--muted);
  font-size: 13.5px; font-weight: 600; padding: 6px 12px; border-radius: 6px; cursor: pointer;
}
@media (hover: hover) { .tab:hover { color: var(--text); filter: none; } }
.tab.active { color: var(--text); background: var(--panel2); border-color: var(--border); }

/* ---------- toolbar ---------- */
#view-play { flex: 1; display: flex; flex-direction: column; min-height: 0; }
.toolbar {
  display: flex; flex-wrap: wrap; align-items: center; gap: 8px 10px;
  padding: 10px 20px; flex: 0 0 auto;
}
.ex-label { font-size: 12.5px; color: var(--muted); }
select {
  background: var(--panel2); color: var(--text); border: 1px solid var(--border);
  border-radius: 6px; padding: 7px 10px; font-size: 13px; cursor: pointer; max-width: 100%;
}
button {
  background: var(--panel2); color: var(--text); border: 1px solid var(--border);
  border-radius: 6px; padding: 7px 16px; font-size: 13.5px; font-weight: 600; cursor: pointer;
  font-family: inherit;
  transition: filter 120ms cubic-bezier(0.23, 1, 0.32, 1), transform 80ms cubic-bezier(0.23, 1, 0.32, 1);
}
@media (hover: hover) { button:hover { filter: brightness(1.18); } }
button:active { transform: scale(0.97); }
button.primary {
  background: var(--accent); border-color: var(--accent); color: var(--bg);
}
:focus-visible { outline: 2px solid var(--accent2); outline-offset: 2px; }
.editor:focus-within { border-color: #3a4763; }
button.dbg { border-color: #3a4763; }
button.stop { color: var(--red); }
button:disabled { opacity: .45; cursor: default; }
#status { font-size: 12.5px; color: var(--muted); margin-left: 4px; }
#status.ok { color: var(--green); }
#status.bad { color: var(--red); }
.hint { margin-left: auto; font-size: 12px; color: var(--muted); }

/* ---------- workspace ---------- */
.workspace {
  flex: 1; min-height: 0;
  display: grid; grid-template-columns: minmax(0, 1.25fr) minmax(0, 1fr);
  gap: 12px; padding: 0 20px 16px;
}
.panel {
  background: var(--panel); border: 1px solid var(--border); border-radius: 5px;
  overflow: hidden;
}
.right { display: flex; flex-direction: column; gap: 12px; min-height: 0; }
.right .io { flex: 1; min-height: 0; display: flex; flex-direction: column; }
.io h3 {
  font-size: 11.5px;  color: var(--muted);
  padding: 10px 14px 8px; border-bottom: 1px solid var(--border); flex: 0 0 auto;
}
.io h3 .muted { text-transform: none; letter-spacing: 0; font-weight: 400; }
.muted { color: var(--muted); }
.scrolly { flex: 1; overflow: auto; padding: 10px 14px; }

/* ---------- editor ---------- */
.editor { display: flex; min-height: 0; }
.gutter {
  flex: 0 0 52px; overflow: hidden; background: var(--panel);
  border-right: 1px solid var(--border); user-select: none;
}
#gutter-inner { padding: 14px 0; }
#gutter-inner div {
  font-family: var(--mono); font-size: 13.5px; line-height: 1.55;
  color: #56617a; text-align: right; padding-right: 12px;
  cursor: pointer; position: relative;
}
#gutter-inner div:hover { color: var(--muted); }
#gutter-inner div.active { color: var(--accent2); font-weight: 700; }
#gutter-inner div.bp { color: var(--red); font-weight: 700; }
#gutter-inner div.bp::before {
  content: ''; position: absolute; left: 6px; top: 50%; transform: translateY(-50%);
  width: 8px; height: 8px; border-radius: 50%; background: var(--red);
}
.code-area { position: relative; flex: 1; min-width: 0; }
#highlight, #code {
  font-family: var(--mono); font-size: 13.5px; line-height: 1.55;
  padding: 14px 16px; white-space: pre; tab-size: 2;
}
#highlight {
  position: absolute; inset: 0; overflow: hidden; pointer-events: none;
}
#highlight .cl { min-height: 1.55em; }
#highlight .cl.active {
  background: rgba(110, 139, 255, 0.16);
  box-shadow: inset 3px 0 0 var(--accent2);
  margin: 0 -16px; padding: 0 16px;
}
#code {
  position: absolute; inset: 0; width: 100%; height: 100%;
  background: transparent; color: transparent; caret-color: var(--accent2);
  border: none; outline: none; resize: none; overflow: auto;
}
#code::selection { background: rgba(110, 139, 255, 0.30); color: transparent; }
#code[readonly] { caret-color: transparent; }

.tok-kw { color: var(--kw); }
.tok-str { color: var(--str); }
.tok-num { color: var(--num); }
.tok-comment { color: var(--comment); font-style: italic; }
.tok-builtin { color: var(--builtin); }
.tok-call { color: var(--call); }
.tok-op { color: var(--op); }
.tok-bool { color: var(--num); }
.tok-plain { color: var(--text); }
.tok-interp { color: #7dcfff; }

/* ---------- output ---------- */
#output { font-family: var(--mono); font-size: 13px; line-height: 1.55; }
.out-line { white-space: pre-wrap; }
.out-note { color: var(--muted); font-style: italic; }
.out-error {
  white-space: pre-wrap; color: #ffb3bd;
  background: rgba(255, 107, 125, 0.08);
  border: 1px solid rgba(255, 107, 125, 0.25);
  border-radius: 4px; padding: 10px 12px; margin-top: 8px;
}
.out-error .first { color: var(--red); font-weight: 700; }
.copy-ai {
  display: inline-block; margin-top: 8px;
  font-family: var(--mono); font-size: 11.5px; font-weight: 600;
  color: #ffb3bd; background: rgba(255, 107, 125, 0.12);
  border: 1px solid rgba(255, 107, 125, 0.35); border-radius: 6px;
  padding: 4px 10px; cursor: pointer;
}
.copy-ai:hover { filter: brightness(1.25); }

/* ---------- variables ---------- */
.frame { margin-bottom: 12px; }
.frame-title {
  font-family: var(--mono); font-size: 12px; color: var(--accent2);
  padding-bottom: 4px; border-bottom: 1px dashed var(--border); margin-bottom: 6px;
}
.var-row {
  display: flex; gap: 10px; font-family: var(--mono); font-size: 12.5px;
  padding: 2px 0;
}
.var-name { color: var(--builtin); flex: 0 0 auto; min-width: 90px; }
.var-val { color: var(--text); white-space: pre-wrap; word-break: break-all; }
.no-vars { color: var(--muted); font-size: 12.5px; font-style: italic; }

/* ---------- results tables ---------- */
.result-h { font-size: 15px; margin: 0 0 4px; color: var(--text); }
.result-note { font-size: 13px; color: var(--muted); margin: 0 0 10px; }
.result-wrap { overflow-x: auto; margin-bottom: 8px; }
.result { border-collapse: collapse; font-size: 14px; min-width: 100%; font-variant-numeric: tabular-nums; }
.result th, .result td { text-align: left; padding: 7px 14px 7px 0; border-bottom: 1px solid var(--border); white-space: nowrap; }
.result th { color: var(--muted); font-weight: 500; font-size: 12.5px; }
.result td { white-space: normal; }
.result td:first-child { white-space: nowrap; }
.result tfoot td { border-bottom: none; font-weight: 600; }
.result .best { color: var(--green); font-weight: 600; }

/* ---------- pages (home, learn, docs) ---------- */
.page { flex: 1; min-height: 0; overflow-y: auto; }
.page-inner { max-width: 1080px; margin: 0 auto; padding: 56px 24px 72px; }
.mono { font-family: var(--mono); }
.visually-hidden { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
a { color: var(--builtin); text-underline-offset: 3px; }
.prose { color: #b9c2d4; line-height: 1.7; font-size: 15px; max-width: 68ch; }
.prose strong { color: var(--text); }
.prose code, .roadmap code, .points code, .cheat-note code, .cli-note code {
  font-family: var(--mono); font-size: 0.88em; background: var(--panel2);
  border-radius: 3px; padding: 1px 4px; color: var(--text);
}
.h-small {
  font-size: 14px; font-weight: 600;
  color: var(--muted); margin-bottom: 10px;
}
.muted { color: var(--muted); }

.codeblock {
  font-family: var(--mono); font-size: 13px; line-height: 1.6;
  background: var(--panel); border: 1px solid var(--border); border-radius: 4px;
  padding: 14px 16px; overflow-x: auto; color: #c4cee2; tab-size: 2;
}
.codeblock.shell { color: var(--text); }
.err-demo { color: #ffb3bd; white-space: pre; }
.copyable {
  display: grid; grid-template-columns: minmax(0, 1fr) auto; align-items: start;
  background: var(--panel); border: 1px solid var(--border); border-radius: 4px;
}
.copyable .codeblock { border: none; background: none; border-radius: 4px 0 0 4px; }
.copy {
  margin: 8px 8px 0 0; padding: 4px 10px; font-size: 12px;
  background: var(--panel2); color: var(--muted);
}
.link-btn {
  background: none; border: none; padding: 0; color: var(--builtin); font-weight: 600; font-size: 13px;
  text-decoration: underline; text-underline-offset: 3px;
}

/* home */
.intro {
  display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1.05fr);
  gap: 48px; align-items: start;
}
.intro h1 { font-size: 46px; line-height: 1.1; letter-spacing: -0.6px; font-weight: 700; margin: 4px 0 18px; max-width: 16ch; text-wrap: balance; }
.sub { font-size: 16px; color: #b9c2d4; line-height: 1.7; margin-bottom: 28px; max-width: 54ch; }
.actions { display: flex; flex-wrap: wrap; gap: 10px; }
button.big { font-size: 15px; padding: 11px 22px; }
.sample { margin: 0; }
.sample figcaption {
  display: flex; justify-content: space-between; align-items: baseline; gap: 12px; flex-wrap: wrap;
  font-size: 12.5px; color: var(--muted); margin-bottom: 8px;
}
.sample .codeblock { border-radius: 4px 4px 0 0; }
.sample-out {
  border: 1px solid var(--border); border-top: none; border-radius: 0 0 4px 4px;
  background: var(--bg); padding: 10px 16px 12px;
}
.out-label { font-size: 12px; color: var(--muted); }
.sample-out pre { font-family: var(--mono); font-size: 13px; line-height: 1.6; color: var(--text); margin-top: 4px; white-space: pre-wrap; }

.points {
  list-style: none; margin: 64px 0 0;
  display: grid; grid-template-columns: repeat(3, minmax(0, 1fr));
  border-top: 1px solid var(--border);
}
.points li {
  padding: 20px 28px 4px 0; font-size: 15px; line-height: 1.6; color: #b9c2d4;
}
.points strong { color: var(--text); }

.split { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 20px; margin-top: 56px; }
.split .codeblock { font-size: 12.5px; }

.honest {
  margin-top: 40px; padding-top: 20px; border-top: 1px solid var(--border);
  font-size: 14px; line-height: 1.7; color: var(--muted); max-width: 80ch;
}
.install { margin-top: 64px; }
.install h2, .docs h2 { font-weight: 650; font-size: 26px; letter-spacing: -0.4px; margin-bottom: 12px; }
.install .prose { margin-bottom: 14px; }
.install .h-small { margin-top: 28px; }
.cmds { display: grid; gap: 10px; }
.cmd-row { display: grid; grid-template-columns: minmax(0, 1.3fr) minmax(0, 1fr); gap: 4px 16px; align-items: center; }
.cmd-row .codeblock { padding-top: 9px; padding-bottom: 9px; }
.cmd-row .copy { margin-top: 5px; }
.cmd-desc { font-size: 14px; color: #b9c2d4; line-height: 1.5; }
.footer-note { margin-top: 64px; color: var(--muted); font-size: 13px; line-height: 1.6; }

/* learn */
.learn {
  display: grid; grid-template-columns: 250px minmax(0, 1fr); gap: 48px;
  max-width: 1080px; margin: 0 auto; padding: 40px 24px 72px;
}
.lesson-nav { position: sticky; top: 0; align-self: start; padding-top: 8px; }
.lesson-nav ol { list-style: none; display: grid; gap: 2px; }
.lesson-link {
  width: 100%; text-align: left; display: flex; gap: 10px; align-items: baseline;
  background: none; border: 1px solid transparent; padding: 7px 10px; font-weight: 500; color: #b9c2d4;
  font-size: 14px;
}
.lesson-link .lesson-n { font-family: var(--mono); font-size: 12px; color: var(--muted); }
.lesson-link[aria-current] { background: var(--panel2); border-color: var(--border); color: var(--text); }
.lesson-link[aria-current] .lesson-n { color: var(--accent2); }
.lesson-pick { display: none; }
.lesson { max-width: 760px; min-width: 0; }
.kicker { font-family: var(--mono); font-size: 12px; color: var(--accent2); margin-bottom: 8px; }
.lesson-title { font-weight: 650; font-size: 34px; letter-spacing: -0.6px; line-height: 1.15; margin-bottom: 14px; }
.lesson-title:focus { outline: none; }
.lesson-intro { margin-bottom: 22px; font-size: 16px; }
.lesson-actions { display: flex; flex-wrap: wrap; align-items: center; gap: 8px 14px; margin-top: 14px; }
.lesson-actions .muted { font-size: 13px; }
.lesson-status { margin-top: 8px; font-size: 13px; min-height: 1em; }
.cli-note {
  font-size: 14px; color: var(--text); line-height: 1.6; margin-bottom: 18px;
  padding: 10px 14px; background: var(--panel2); border: 1px solid var(--border); border-radius: 6px;
}
.file-name { font-size: 12.5px; color: var(--muted); margin: 18px 0 6px; }
.pager {
  display: flex; justify-content: space-between; gap: 12px; margin-top: 48px;
  padding-top: 20px; border-top: 1px solid var(--border);
}
.pager button {
  display: flex; flex-direction: column; gap: 2px; padding: 10px 14px; text-align: left;
  max-width: 48%; font-size: 14px;
}
.pager .pager-next { text-align: right; margin-left: auto; }
.pager .muted { font-size: 12px; font-weight: 500; }

/* docs */
.docs-title { font-weight: 650; font-size: 44px; letter-spacing: -1px; margin-bottom: 12px; }
.toc { display: flex; flex-wrap: wrap; gap: 6px 20px; margin: 20px 0 8px; font-size: 14px; }
.toc a { color: var(--muted); text-decoration: none; }
@media (hover: hover) { .toc a:hover { color: var(--text); } }
.docs h2 { margin-top: 56px; scroll-margin-top: 16px; }
.cheats { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 28px 20px; margin-top: 20px; }
.cheat h3 { font-size: 14px; font-weight: 600; color: var(--text); margin-bottom: 8px; }
.cheat .codeblock { font-size: 12.5px; }
.cheat-note { font-size: 13px; color: var(--muted); line-height: 1.6; margin-top: 8px; }
.bench { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 32px 40px; margin-top: 24px; }
.result-note { line-height: 1.5; }
.roadmap { margin: 16px 0 0 20px; color: #b9c2d4; line-height: 1.75; font-size: 14.5px; max-width: 80ch; }
.roadmap li { margin-bottom: 6px; }
.roadmap strong { color: var(--text); }

/* ---------- errors page ---------- */
.err-cases { display: flex; flex-wrap: wrap; gap: 6px; margin: 28px 0 18px; }
.err-cases .tab { border-color: var(--border); }
.err-cases .tab[aria-selected="true"] { color: var(--text); background: var(--panel2); border-color: var(--muted); }
.err-task { color: #b9c2d4; font-size: 15px; line-height: 1.6; margin-bottom: 28px; }
.err-task code { font-family: var(--mono); font-size: 0.88em; background: var(--panel2); border-radius: 3px; padding: 1px 4px; color: var(--text); }
.err-col {
  display: grid; grid-template-columns: minmax(0, 5fr) minmax(0, 7fr); gap: 6px 16px;
  padding: 22px 0; border-top: 1px solid var(--border);
}
.err-head { grid-column: 1 / -1; display: flex; align-items: baseline; gap: 14px; flex-wrap: wrap; }
.err-head .h-small { color: var(--text); font-size: 15px; margin: 0; }
.err-outcome { font-size: 13px; font-weight: 600; }
.err-outcome.is-good { color: var(--green); }
.err-outcome.is-bad { color: var(--red); }
.err-code, .err-out { font-size: 12.5px; margin: 0; }
.err-code { align-self: start; }
.err-out { white-space: pre-wrap; overflow-wrap: anywhere; }
.err-label { font-family: var(--mono); font-size: 12px; color: var(--muted); overflow-wrap: anywhere; margin-bottom: 6px; }
.err-foot { margin-top: 28px; max-width: 80ch; }
.err-more { margin-top: 10px; }

/* ---------- small screens ---------- */
@media (max-width: 980px) {
  .intro { grid-template-columns: minmax(0, 1fr); gap: 36px; }
  .points { grid-template-columns: minmax(0, 1fr); }
  .points li { padding: 16px 0 8px; border-bottom: 1px solid var(--border); }
  .split, .cheats, .bench { grid-template-columns: minmax(0, 1fr); }
}
@media (max-width: 900px) {
  #view-play { overflow-y: auto; }
  .workspace { grid-template-columns: minmax(0, 1fr); grid-template-rows: minmax(300px, 52vh) auto; }
  .right .io { min-height: 200px; }
  .hint { display: none; }
}
@media (max-width: 760px) {
  .err-col { grid-template-columns: minmax(0, 1fr); }
  .learn { grid-template-columns: minmax(0, 1fr); gap: 20px; padding-top: 20px; }
  .lesson-nav { position: static; }
  .lesson-nav ol, .lesson-nav .h-small { display: none; }
  .lesson-pick { display: block; }
  .lesson-pick select { width: 100%; font-size: 15px; padding: 10px; }
  .cmd-row { grid-template-columns: minmax(0, 1fr); }
  .cmd-desc { margin-bottom: 6px; }
}
@media (max-width: 560px) {
  header { padding: 10px 16px; }
  header nav { width: 100%; justify-content: space-between; }
  .tab { padding: 6px 8px; }
  .page-inner { padding: 32px 16px 56px; }
  .learn { padding-left: 16px; padding-right: 16px; }
  .toolbar { padding: 10px 16px; }
  .workspace { padding: 0 16px 16px; }
  .intro h1 { font-size: 46px; line-height: 1.1; letter-spacing: -0.6px; font-weight: 700; margin: 4px 0 18px; max-width: 16ch; text-wrap: balance; }
    .lesson-title { font-weight: 650; font-size: 28px; }
  .docs-title { font-weight: 650; font-size: 36px; }
  .codeblock { font-size: 12.5px; padding: 12px; }
  .pager button { max-width: 50%; }
}

.asof { color: var(--muted); font-size: 0.9em; white-space: nowrap; }