/* cron-utils-web: single stylesheet, zero framework.
 * Shape scale: 10px radius everywhere (buttons 999px pills are the one
 * documented exception). One accent (deep teal); per-field token tints below
 * are functional coding so each preview token matches its field, not decor.
 * Theme: light by default, dark via prefers-color-scheme (one auto theme). */
:root {
  --bg: #fafaf9;
  --surface: #ffffff;
  --ink: #1c1917;
  --muted: #57534e;
  --faint: #78716c;
  --line: #e7e5e4;
  --accent: #0f766e;
  --accent-ink: #ffffff;
  --accent-soft: #ccfbf1;
  --danger: #b91c1c;
  --danger-soft: #fee2e2;
  --ok: #15803d;
  --radius: 10px;
  --max: 72rem;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --mono: ui-monospace, "SF Mono", "Cascadia Mono", Menlo, Consolas, monospace;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #1c1917;
    --surface: #292524;
    --ink: #f5f5f4;
    --muted: #d6d3d1;
    --faint: #a8a29e;
    --line: #44403c;
    --accent: #2dd4bf;
    --accent-ink: #042f2e;
    --accent-soft: #134e4a;
    --danger: #fca5a5;
    --danger-soft: #450a0a;
    --ok: #86efac;
  }
}

* { box-sizing: border-box; }

body {
  font-family: var(--sans);
  line-height: 1.5;
  margin: 0;
  padding: 0 1rem 2rem;
  color: var(--ink);
  background: var(--bg);
}

header.site {
  max-width: var(--max);
  margin: 0 auto;
  padding: 2rem 0 1rem;
  border-bottom: 2px solid var(--accent);
}

header.site h1 {
  font-size: 1.75rem;
  letter-spacing: -0.02em;
  margin: 0 0 0.25rem;
}

header.site p {
  margin: 0;
  color: var(--muted);
  max-width: 65ch;
}

main.site-main {
  max-width: var(--max);
  margin: 0 auto;
  display: grid;
  gap: 1.5rem;
  padding-top: 1.5rem;
}

section.card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.25rem 1.25rem 1.5rem;
}

section.card h2 {
  margin: 0 0 0.25rem;
  font-size: 1.25rem;
  letter-spacing: -0.01em;
}

section.card > p:first-of-type {
  margin-top: 0;
  color: var(--muted);
  max-width: 75ch;
}

section.card h3 {
  font-size: 1rem;
  margin: 1.25rem 0 0.5rem;
}

.row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem 1.5rem;
  align-items: end;
  margin: 0.75rem 0;
}

label {
  display: inline-flex;
  flex-direction: column;
  gap: 0.25rem;
  font-weight: 600;
  font-size: 0.9rem;
}

.row label { min-width: 10rem; }
.row label:has(#gen-expression) { flex: 1 1 20rem; }

input[type="text"], select {
  font: inherit;
  font-weight: 400;
  padding: 0.4rem 0.6rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  color: var(--ink);
  max-width: 100%;
}

input[type="text"] {
  font-family: var(--mono);
  font-size: 0.95rem;
}

input[aria-invalid="true"] {
  border-color: var(--danger);
  background: var(--danger-soft);
}

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

button {
  font: inherit;
  font-size: 0.9rem;
  font-weight: 600;
  padding: 0.4rem 0.9rem;
  border: 1px solid var(--accent);
  border-radius: 999px;
  background: var(--accent);
  color: var(--accent-ink);
  cursor: pointer;
}

/* Reading result components: reading and schedule panels side by side,
 * stacked on narrow screens. */
.read-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.75rem;
  margin: 0.75rem 0;
}

@media (max-width: 55rem) {
  .read-grid { grid-template-columns: 1fr; }
}

article.panel {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 0.75rem 1rem 1rem;
  background: var(--surface);
}

article.panel h3 {
  margin: 0 0 0.4rem;
  font-size: 1rem;
}

article.panel .lede { margin: 0 0 0.5rem; }

.standard {
  margin: 0;
  font-size: 0.85rem;
  color: var(--muted);
}

.standard code {
  font-family: var(--mono);
  font-size: 0.9rem;
  color: var(--ink);
}

ol.timeline {
  list-style: none;
  margin: 0.25rem 0 0.6rem;
  padding: 0;
  display: grid;
  gap: 0.35rem;
  counter-reset: run;
}

.timeline li {
  display: flex;
  gap: 0.6rem;
  align-items: baseline;
  counter-increment: run;
  font-family: var(--mono);
  font-size: 0.9rem;
}

.timeline li::before {
  content: counter(run);
  flex: none;
  width: 1.4rem;
  height: 1.4rem;
  line-height: 1.4rem;
  text-align: center;
  font-size: 0.75rem;
  font-weight: 700;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent);
}

[hidden] { display: none !important; }
button:active { transform: scale(0.98); }

button.ghost {
  background: transparent;
  color: var(--accent);
}

.presets {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin: 0.75rem 0;
}

.presets button {
  background: transparent;
  color: var(--accent);
}

/* Field grid: each field carries its own --chip tint so the hint, the
 * input's left edge and the preview token visibly belong together. */
.field-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(17rem, 1fr));
  gap: 0.75rem;
  margin: 0.75rem 0;
}

.field {
  --chip: var(--accent-soft);
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
  border: 1px solid var(--line);
  border-top: 4px solid var(--chip);
  border-radius: var(--radius);
  padding: 0.6rem 0.7rem 0.7rem;
}

.field[data-field="SECOND"] { --chip: #fda4af; }
.field[data-field="MINUTE"] { --chip: #fdba74; }
.field[data-field="HOUR"] { --chip: #fcd34d; }
.field[data-field="DAY_OF_MONTH"] { --chip: #86efac; }
.field[data-field="MONTH"] { --chip: #5eead4; }
.field[data-field="DAY_OF_WEEK"] { --chip: #93c5fd; }
.field[data-field="YEAR"] { --chip: #c4b5fd; }
.field[data-field="DAY_OF_YEAR"] { --chip: #f0abfc; }

@media (prefers-color-scheme: dark) {
  .field[data-field="SECOND"] { --chip: #881337; }
  .field[data-field="MINUTE"] { --chip: #9a3412; }
  .field[data-field="HOUR"] { --chip: #854d0e; }
  .field[data-field="DAY_OF_MONTH"] { --chip: #14532d; }
  .field[data-field="MONTH"] { --chip: #134e4a; }
  .field[data-field="DAY_OF_WEEK"] { --chip: #1e3a8a; }
  .field[data-field="YEAR"] { --chip: #4c1d95; }
  .field[data-field="DAY_OF_YEAR"] { --chip: #701a75; }
}

.field label {
  flex-direction: row;
  align-items: center;
  justify-content: space-between;
}

.badge {
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  padding: 0.1rem 0.5rem;
  border-radius: 999px;
  border: 1px solid var(--line);
  color: var(--faint);
}

.badge.req { color: var(--accent); border-color: var(--accent); }
.badge.opt { color: var(--faint); }

.hint {
  font-family: var(--mono);
  font-size: 0.75rem;
  color: var(--faint);
}

/* Field starters: clickable chips that fill the field above them. */
.try {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.35rem;
  font-size: 0.8rem;
  color: var(--faint);
}

.try button {
  font-family: var(--mono);
  font-weight: 400;
  font-size: 0.75rem;
  padding: 0.15rem 0.6rem;
  background: transparent;
  color: var(--accent);
}

/* Teachable syntax shelf inside each field card. */
details.guide {
  border-top: 1px solid var(--line);
  padding-top: 0.35rem;
  font-size: 0.8rem;
  color: var(--muted);
}

details.guide summary {
  cursor: pointer;
  font-weight: 600;
  font-size: 0.8rem;
  color: var(--muted);
}

details.guide ul {
  margin: 0.35rem 0 0;
  padding-left: 1.1rem;
  display: grid;
  gap: 0.3rem;
}

details.guide li code {
  font-family: var(--mono);
  font-size: 0.75rem;
  background: var(--bg);
  padding: 0 0.3rem;
  border-radius: 4px;
}

details.guide li button {
  font-family: var(--mono);
  font-weight: 400;
  font-size: 0.75rem;
  padding: 0.1rem 0.5rem;
  margin: 0 0.25rem;
}

.meaning { font-size: 0.8rem; color: var(--muted); }
.meaning.ok::before { content: "= "; color: var(--ok); }
.meaning.bad { color: var(--danger); }

.error { color: var(--danger); }
.hint { color: var(--faint); }
.meta { color: var(--faint); font-size: 0.85rem; }
.lede { font-size: 1.1rem; }

/* Derived-output blocks: the box mirrors the fields, typing here fills them. */
.expr-block,
.equiv-block {
  margin: 1rem 0 0;
  border: 1px dashed var(--line);
  border-radius: var(--radius);
  padding: 0.75rem 1rem;
}

.expr-block h3,
.equiv-block h3 {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--faint);
  margin: 0 0 0.4rem;
}

.expr-row label:has(#gen-expression) { flex: 1 1 20rem; }

#gen-expression {
  font-size: 1.05rem;
}

.copy-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem 0.75rem;
  margin-top: 0.6rem;
}

dl.equiv {
  display: grid;
  gap: 0.4rem;
  margin: 0.5rem 0 0;
}

dl.equiv div {
  display: grid;
  grid-template-columns: 7rem 1fr;
  gap: 0.75rem;
  align-items: baseline;
  border-bottom: 1px solid var(--line);
  padding-bottom: 0.4rem;
}

dl.equiv dt { font-weight: 700; font-size: 0.85rem; }
dl.equiv dd { margin: 0; font-family: var(--mono); font-size: 0.9rem; overflow-x: auto; }
dl.equiv div.same dt::after { content: " (this type)"; font-weight: 400; color: var(--faint); }
dl.equiv div.na dd { color: var(--faint); }

details.examples {
  margin-top: 1.25rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 0.6rem 1rem;
}

details.examples summary {
  font-weight: 700;
  cursor: pointer;
}

details.examples ul {
  padding-left: 1.25rem;
  display: grid;
  gap: 0.5rem;
}

details.examples li button { margin-left: 0.5rem; font-size: 0.8rem; padding: 0.2rem 0.7rem; }

#gen-runs {
  font-family: var(--mono);
  font-size: 0.9rem;
  display: grid;
  gap: 0.25rem;
}

footer.site {
  max-width: var(--max);
  margin: 1.5rem auto 0;
  border-top: 1px solid var(--line);
  padding-top: 1rem;
  font-size: 0.9rem;
  color: var(--muted);
}

@media (prefers-reduced-motion: reduce) {
  button:active { transform: none; }
}