/* Numerical Expressions website.
   White paper, black ink and strong rules, with dark orange and dark green accents. */

:root {
  --paper: #ffffff;
  --wash: #f6f6f3;
  --ink: #111111;
  --muted: #5c5c5c;
  --hairline: #e2e2de;
  --rule: #111111;

  --orange: #b8470b;       /* dark orange: actions, active states, notes */
  --orange-wash: #fff1e7;
  --green: #0b6b3a;        /* dark green: the mark, confirmations, "ready" */
  --green-wash: #e9f4ed;
  --red: #a3201a;          /* refusals only */
  --red-wash: #fbeae8;

  --display: "Archivo", "Helvetica Neue", Arial, sans-serif;
  --serif: "Newsreader", Georgia, "Times New Roman", serif;
  --mono: "IBM Plex Mono", ui-monospace, "SFMono-Regular", Consolas, monospace;

  color-scheme: light;
}

* { box-sizing: border-box; }

[hidden] { display: none !important; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--display);
  font-size: 16px;
  line-height: 1.5;
  padding-inline: 20px;
  padding-block: 0 56px;
}

.wrap { max-width: 1200px; margin: 0 auto; }

a { color: var(--orange); text-underline-offset: 2px; }
a:hover { color: var(--ink); }

:focus-visible { outline: 3px solid var(--orange); outline-offset: 2px; }

.label {
  font-family: var(--mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

/* Masthead ----------------------------------------------------------------- */

.masthead {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px 24px;
  padding-block: 18px 16px;
  border-bottom: 2px solid var(--rule);
}

.wordmark {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  font-stretch: 85%;
  font-size: 22px;
  letter-spacing: -0.01em;
  color: var(--ink);
  text-decoration: none;
}

.wordmark .mark {
  width: 14px;
  height: 14px;
  background: var(--green);
  flex: none;
}

.masthead-tools { display: flex; align-items: center; gap: 16px; flex-wrap: wrap; }

.status {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--muted);
}

.status::before {
  content: "";
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--orange);
  animation: pulse 1.2s ease-in-out infinite;
}

.status[data-state="ready"] { color: var(--green); }
.status[data-state="ready"]::before { background: var(--green); animation: none; }
.status[data-state="failed"] { color: var(--red); }
.status[data-state="failed"]::before { background: var(--red); animation: none; }

@keyframes pulse { 50% { opacity: 0.3; } }

.lang { display: flex; align-items: center; gap: 8px; }

/* Intro ----------------------------------------------------------------------- */

.intro {
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr);
  gap: 16px 48px;
  align-items: end;
  padding-block: 36px 28px;
}

.intro h1 {
  margin: 0;
  font-weight: 800;
  font-stretch: 80%;
  font-size: clamp(34px, 5.4vw, 62px);
  line-height: 1;
  letter-spacing: -0.02em;
  text-wrap: balance;
}

.intro h1 em { font-style: normal; color: var(--orange); }

.intro p {
  margin: 0;
  font-family: var(--serif);
  font-size: 19px;
  line-height: 1.45;
  max-width: 34em;
  color: #2b2b2b;
}

@media (max-width: 760px) {
  .intro { grid-template-columns: 1fr; padding-block: 26px 20px; }
}

/* Task picker ----------------------------------------------------------------------- */

.tasks-title { margin: 0 0 10px; color: var(--muted); }

.tasks {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
  border-top: 1px solid var(--rule);
  border-left: 1px solid var(--rule);
}

.task {
  font: inherit;
  text-align: left;
  cursor: pointer;
  color: var(--ink);
  background: var(--paper);
  border: 0;
  border-right: 1px solid var(--rule);
  border-bottom: 1px solid var(--rule);
  padding: 12px 14px 14px;
  display: grid;
  gap: 4px;
  align-content: start;
}

.task .label { color: var(--orange); }
.task b { font-weight: 700; font-size: 16px; line-height: 1.25; }
.task span.hint { color: var(--muted); font-size: 13px; line-height: 1.35; }
.task:hover { background: var(--wash); }
.task[aria-pressed="true"] { background: var(--ink); color: var(--paper); }
.task[aria-pressed="true"] .label { color: #ffb487; }
.task[aria-pressed="true"] span.hint { color: #cfcfcf; }

/* Workspace --------------------------------------------------------------------- */

.desk {
  display: grid;
  grid-template-columns: minmax(290px, 400px) minmax(0, 1fr);
  gap: 32px;
  margin-top: 28px;
  align-items: start;
}

@media (max-width: 860px) { .desk { grid-template-columns: 1fr; } }

.panel-head {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 8px 16px;
  height: 48px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--rule);
}

.panel-title { margin: 0; }

form.notebook { display: grid; gap: 22px; }

.examples { display: flex; flex-wrap: wrap; gap: 6px; }

.chip {
  font: inherit;
  font-size: 13px;
  cursor: pointer;
  color: var(--ink);
  background: var(--paper);
  border: 1px solid var(--rule);
  padding: 4px 10px;
}

.chip:hover { background: var(--wash); }
.chip[aria-pressed="true"] { background: var(--orange); border-color: var(--orange); color: #fff; }

.fields { display: grid; grid-template-columns: 1fr 1fr; gap: 14px 12px; }
.field { display: grid; gap: 5px; align-content: start; }
.field.wide { grid-column: 1 / -1; }
.field label { font-size: 14px; font-weight: 600; }
.field small { color: var(--muted); font-size: 12.5px; line-height: 1.35; }
.field small.read { color: var(--green); font-family: var(--mono); font-size: 12px; }
.field small.bad { color: var(--red); }

@media (max-width: 480px) { .fields { grid-template-columns: 1fr; } }

input[type="text"],
select {
  font: inherit;
  font-size: 15px;
  color: var(--ink);
  background: var(--paper);
  border: 1px solid #8a8a86;
  border-radius: 0;
  padding: 9px 10px;
  width: 100%;
}

select { width: auto; padding-block: 6px; }

input.num { font-family: var(--mono); font-variant-numeric: tabular-nums; }
input[aria-invalid="true"] { border-color: var(--red); background: var(--red-wash); }

.group { display: grid; gap: 14px; }
.group-title { margin: 0; color: var(--muted); }

.seg { display: flex; flex-wrap: wrap; border: 1px solid var(--rule); }

.seg button {
  flex: 1 1 auto;
  font: inherit;
  font-size: 13.5px;
  padding: 8px 10px;
  cursor: pointer;
  background: var(--paper);
  color: var(--ink);
  border: 0;
  border-right: 1px solid var(--rule);
}

.seg button:last-child { border-right: 0; }
.seg button:hover { background: var(--wash); }
.seg button[aria-pressed="true"] { background: var(--ink); color: var(--paper); }

.check { display: flex; gap: 10px; align-items: flex-start; font-size: 14.5px; line-height: 1.4; }
.check input { margin: 3px 0 0; width: 16px; height: 16px; accent-color: var(--orange); flex: none; }

/* Suggestions --------------------------------------------------------------------------- */

.proofs { display: grid; gap: 16px; min-width: 0; }


.button {
  font: inherit;
  font-size: 13.5px;
  font-weight: 600;
  cursor: pointer;
  color: var(--paper);
  background: var(--ink);
  border: 1px solid var(--ink);
  padding: 6px 12px;
}

.button:hover { background: var(--orange); border-color: var(--orange); }
.button.done { background: var(--green); border-color: var(--green); }

#results { display: grid; gap: 14px; }

.placeholder {
  font-family: var(--serif);
  font-size: 18px;
  color: var(--muted);
  padding: 20px;
  background: var(--wash);
  border: 1px dashed #b9b9b4;
}

.kind { border: 1px solid var(--rule); background: var(--paper); }

.kind header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 8px;
  padding: 7px 14px;
  border-bottom: 1px solid var(--rule);
}

/* Suggestion labels in normal sentence case, in the headline font, for readability. */
.kind header .label {
  font-family: var(--display);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0;
  text-transform: none;
  color: var(--orange);
}
.kind header code { font-family: var(--mono); font-size: 11.5px; color: var(--muted); }

.line {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 14px;
  align-items: start;
  padding: 13px 14px;
}

.line + .line { border-top: 1px solid var(--hairline); }

.line p {
  margin: 0;
  font-family: var(--display);
  font-size: 19px;
  line-height: 1.5;
  overflow-wrap: anywhere;
}

.copy {
  font: inherit;
  font-size: 12.5px;
  font-weight: 600;
  cursor: pointer;
  color: var(--ink);
  background: var(--paper);
  border: 1px solid var(--rule);
  padding: 4px 10px;
  white-space: nowrap;
}

.copy:hover { background: var(--ink); color: var(--paper); }
.copy.done { background: var(--green); border-color: var(--green); color: #fff; }

@media (max-width: 520px) {
  .line { grid-template-columns: 1fr; }
  .copy { justify-self: start; }
  .line p { font-size: 18px; }
}

.flag {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 10px;
  padding: 11px 14px;
  font-size: 14.5px;
  line-height: 1.45;
  border-top: 1px solid var(--rule);
}

.flag .label { padding: 1px 6px; height: fit-content; margin-top: 1px; }
.flag.note { background: var(--orange-wash); }
.flag.note .label { color: #fff; background: var(--orange); }
.flag.error { background: var(--red-wash); border-top: 0; }
.flag.error .label { color: #fff; background: var(--red); }


/* Footer --------------------------------------------------------------------------- */

.colophon {
  margin-top: 48px;
  padding-top: 16px;
  border-top: 2px solid var(--rule);
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 16px 40px;
  font-size: 14px;
  color: var(--muted);
}

.colophon p { margin: 0; }
.colophon strong { color: var(--ink); }

@media (prefers-reduced-motion: reduce) {
  .status::before { animation: none; }
}