/* ============================================================
   CalculatorWorks — global stylesheet
   Brand is a placeholder: find-and-replace "CalculatorWorks" + "calculatorworks.net"
   Motif: ink on graph paper. Signature: the hero IS a calculator.
   ============================================================ */

:root {
  --ink: #122019;           /* deep pine ink */
  --ink-soft: #4c5f56;
  --paper: #f6f8f6;         /* cool paper */
  --grid-line: rgba(18, 32, 25, .055);
  --card: #ffffff;
  --line: #dbe4de;
  --teal: #0f766e;          /* primary action */
  --teal-deep: #0b5952;
  --amber: #d97706;         /* equals / result accent */
  --ok: #1e8e5a;
  --warn: #c96f0a;
  --bad: #b3423a;
  --radius: 14px;
  --shadow: 0 1px 2px rgba(18, 32, 25, .06), 0 8px 24px rgba(18, 32, 25, .07);
  --font: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --mono: ui-monospace, "Cascadia Mono", "SF Mono", Consolas, monospace;
}

@media (prefers-color-scheme: dark) {
  :root {
    --ink: #e7efe9;
    --ink-soft: #9db3a8;
    --paper: #0e1713;
    --grid-line: rgba(231, 239, 233, .05);
    --card: #16221c;
    --line: #26362e;
    --teal: #34b3a5;
    --teal-deep: #5cc9bd;
    --amber: #f0a13c;
    --shadow: 0 1px 2px rgba(0, 0, 0, .4), 0 8px 24px rgba(0, 0, 0, .35);
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: var(--font);
  color: var(--ink);
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
  /* graph-paper background */
  background:
    linear-gradient(var(--grid-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-line) 1px, transparent 1px),
    var(--paper);
  background-size: 24px 24px, 24px 24px, auto;
}

a { color: var(--teal); text-decoration: none; }
a:hover { text-decoration: underline; }
:focus-visible { outline: 3px solid var(--amber); outline-offset: 2px; border-radius: 4px; }

.container { max-width: 1080px; margin: 0 auto; padding: 0 1rem; }

/* ---------- Header / nav ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: color-mix(in srgb, var(--paper) 90%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}
.nav { display: flex; align-items: center; gap: 1rem; min-height: 3.5rem; }
.brand {
  font-weight: 800;
  font-size: 1.15rem;
  letter-spacing: -.02em;
  color: var(--ink);
  display: flex;
  align-items: center;
  gap: .5rem;
  white-space: nowrap;
}
.brand:hover { text-decoration: none; }
.brand .mark {
  width: 1.05rem; height: 1.05rem;
  border-radius: 4px;
  background: var(--teal);
  color: #fff;
  font-size: .8rem;
  font-weight: 800;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex: none;
}
.nav-toggle {
  margin-left: auto;
  display: none;
  background: none;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: .4rem .6rem;
  font-size: 1.1rem;
  color: var(--ink);
  cursor: pointer;
}
.nav-links { margin-left: auto; display: flex; gap: .25rem; list-style: none; padding: 0; flex-wrap: wrap; }
.nav-links a {
  display: block;
  padding: .45rem .7rem;
  border-radius: 8px;
  color: var(--ink-soft);
  font-weight: 600;
  font-size: .92rem;
}
.nav-links a:hover { color: var(--ink); background: var(--line); text-decoration: none; }
.nav-links a[aria-current="page"] { color: var(--teal); background: color-mix(in srgb, var(--teal) 12%, transparent); }

@media (max-width: 920px) {
  .nav-toggle { display: block; }
  .nav-links {
    display: none;
    position: absolute;
    left: 0; right: 0; top: 100%;
    margin: 0;
    padding: .5rem 1rem 1rem;
    background: var(--paper);
    border-bottom: 1px solid var(--line);
    flex-direction: column;
  }
  .nav-links.open { display: flex; }
}

/* ---------- Hero ---------- */
.hero {
  color: #f2f7f4;
  padding: 2.25rem 0 2.5rem;
  background:
    linear-gradient(rgba(242, 247, 244, .05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(242, 247, 244, .05) 1px, transparent 1px),
    linear-gradient(160deg, #0b5952, #122019);
  background-size: 24px 24px, 24px 24px, auto;
}
.hero .eyebrow {
  text-transform: uppercase;
  letter-spacing: .14em;
  font-size: .75rem;
  font-weight: 700;
  opacity: .85;
  margin: 0 0 .25rem;
}
.hero h1 { margin: 0 0 .35rem; font-size: clamp(1.6rem, 4vw, 2.3rem); letter-spacing: -.02em; line-height: 1.15; }
.hero p.lede { margin: 0; max-width: 46rem; opacity: .92; font-size: 1.02rem; }

main { padding: 1.75rem 0 3rem; }

/* ---------- Cards / layout ---------- */
.grid { display: grid; gap: 1rem; }
.grid.cols-2 { grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); }
.grid.cols-3 { grid-template-columns: repeat(auto-fit, minmax(230px, 1fr)); }
.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 1.1rem 1.2rem;
}
.card h2, .card h3 { margin-top: 0; }
.section-title { font-size: 1.35rem; letter-spacing: -.01em; margin: 2rem 0 .9rem; }
.muted { color: var(--ink-soft); }
.small { font-size: .85rem; }
.mono { font-family: var(--mono); font-variant-numeric: tabular-nums; }

/* ---------- Forms ---------- */
label { font-weight: 600; font-size: .9rem; display: block; margin-bottom: .3rem; }
input[type="text"], input[type="number"], input[type="date"], select {
  width: 100%;
  padding: .6rem .7rem;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--card);
  color: var(--ink);
  font: inherit;
}
input:focus, select:focus { border-color: var(--teal); }
.btn {
  display: inline-block;
  border: 0;
  border-radius: 10px;
  padding: .62rem 1.1rem;
  background: var(--teal);
  color: #fff;
  font: inherit;
  font-weight: 700;
  cursor: pointer;
}
.btn:hover { background: var(--teal-deep); }
.btn.ghost { background: transparent; color: var(--teal); border: 1px solid var(--teal); }
.btn.small { padding: .35rem .7rem; font-size: .85rem; }
.field-row { display: flex; gap: .75rem; flex-wrap: wrap; align-items: end; }
.field-row > div { flex: 1 1 160px; }

/* Segmented toggle (metric/imperial etc.) */
.seg { display: inline-flex; border: 1px solid var(--line); border-radius: 10px; overflow: hidden; }
.seg button {
  border: 0;
  background: var(--card);
  color: var(--ink-soft);
  font: inherit;
  font-weight: 600;
  padding: .5rem .9rem;
  cursor: pointer;
}
.seg button[aria-pressed="true"] { background: var(--teal); color: #fff; }

/* ---------- Result panels ---------- */
.result {
  border-left: 4px solid var(--amber);
  background: color-mix(in srgb, var(--amber) 8%, var(--card));
  border-radius: 10px;
  padding: 1rem 1.1rem;
  margin-top: 1rem;
}
.result .big {
  font-size: clamp(1.8rem, 5vw, 2.6rem);
  font-weight: 800;
  letter-spacing: -.02em;
  font-variant-numeric: tabular-nums;
}
.result[hidden] { display: none; }

/* ---------- The calculator (home hero signature) ---------- */
.calc {
  max-width: 380px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 18px;
  box-shadow: var(--shadow);
  padding: 1rem;
  margin-top: 1.25rem;
}
.calc-display {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: .75rem .9rem;
  text-align: right;
  margin-bottom: .75rem;
  overflow: hidden;
}
.calc-display .expr {
  min-height: 1.2em;
  font-size: .9rem;
  color: var(--ink-soft);
  font-variant-numeric: tabular-nums;
  word-break: break-all;
}
.calc-display .val {
  font-size: clamp(1.9rem, 8vw, 2.6rem);
  font-weight: 800;
  letter-spacing: -.02em;
  font-variant-numeric: tabular-nums;
  color: var(--ink);
  word-break: break-all;
}
.calc-keys { display: grid; grid-template-columns: repeat(4, 1fr); gap: .5rem; }
.calc-keys button {
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--card);
  color: var(--ink);
  font: inherit;
  font-size: 1.25rem;
  font-weight: 600;
  padding: .8rem 0;
  cursor: pointer;
  font-variant-numeric: tabular-nums;
}
.calc-keys button:hover { background: var(--line); }
.calc-keys .op { color: var(--teal); font-weight: 800; }
.calc-keys .eq { background: var(--amber); border-color: var(--amber); color: #fff; font-weight: 800; }
.calc-keys .eq:hover { background: #b46205; }
.calc-keys .danger { color: var(--bad); }

/* ---------- Tables ---------- */
.table-wrap { overflow-x: auto; }
table { border-collapse: collapse; width: 100%; font-size: .92rem; }
th, td { padding: .55rem .65rem; text-align: left; border-bottom: 1px solid var(--line); }
th { font-size: .78rem; text-transform: uppercase; letter-spacing: .06em; color: var(--ink-soft); }
td.num, th.num { text-align: right; font-variant-numeric: tabular-nums; }

/* ---------- Ad slots (Google AdSense placeholders) ---------- */
.ad-slot {
  margin: 1.5rem auto;
  min-height: 100px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px dashed var(--line);
  border-radius: 10px;
  color: var(--ink-soft);
  font-size: .75rem;
  text-transform: uppercase;
  letter-spacing: .12em;
  background: color-mix(in srgb, var(--card) 60%, transparent);
}
.ad-slot.leaderboard { min-height: 90px; }

/* ---------- Footer ---------- */
.site-footer {
  border-top: 1px solid var(--line);
  padding: 1.75rem 0 2.25rem;
  color: var(--ink-soft);
  font-size: .88rem;
  background: var(--paper);
}
.site-footer .cols { display: flex; gap: 2rem; flex-wrap: wrap; justify-content: space-between; }
.site-footer ul { list-style: none; padding: 0; margin: .4rem 0 0; }
.site-footer li { margin: .25rem 0; }

.visually-hidden {
  position: absolute; width: 1px; height: 1px;
  overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap;
}