/* Shared styles for every tool page. */
:root {
  --bg: #f7f7f5;
  --surface: #ffffff;
  --text: #1c1c1a;
  --muted: #5f5f5a;
  --border: #deddd8;
  --accent: #0f6e56;
  --accent-soft: #e3f2ec;
  --up: #0f6e56;
  --down: #b3261e;
  --warn-bg: #fff6e0;
  --warn-text: #6b4e00;
  --radius: 12px;
  --shadow: 0 1px 2px rgba(0,0,0,.04), 0 4px 16px rgba(0,0,0,.05);
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #141413; --surface: #1e1e1c; --text: #ecebe6; --muted: #a3a29c;
    --border: #34332f; --accent: #4fc39e; --accent-soft: #173a30;
    --up: #4fc39e; --down: #f2867e; --warn-bg: #3a3014; --warn-text: #f0d68a;
    --shadow: none; color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #141413; --surface: #1e1e1c; --text: #ecebe6; --muted: #a3a29c;
  --border: #34332f; --accent: #4fc39e; --accent-soft: #173a30;
  --up: #4fc39e; --down: #f2867e; --warn-bg: #3a3014; --warn-text: #f0d68a;
  --shadow: none; color-scheme: dark;
}

* { box-sizing: border-box; }
body {
  margin: 0; background: var(--bg); color: var(--text);
  font: 16px/1.65 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}
a { color: var(--accent); }
.wrap { max-width: 760px; margin: 0 auto; padding: 0 16px; }

.site-head { border-bottom: 1px solid var(--border); background: var(--surface); }
.site-head .wrap { display: flex; align-items: center; justify-content: space-between; height: 56px; }
.logo { font-weight: 700; text-decoration: none; color: var(--text); }
.site-head nav a { color: var(--muted); text-decoration: none; margin-left: 16px; font-size: 15px; }

.crumbs { font-size: 14px; color: var(--muted); margin: 20px 0 4px; }
.crumbs a { color: var(--muted); }
h1 { font-size: clamp(28px, 5vw, 38px); line-height: 1.2; margin: 4px 0 8px; letter-spacing: -.01em; }
.lede { color: var(--muted); margin: 22px 0 20px; font-size: 17px; }

/* ---- Tool card ---- */
.tool { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); box-shadow: var(--shadow); overflow: hidden; }
.tabs { display: flex; overflow-x: auto; border-bottom: 1px solid var(--border); scrollbar-width: none; }
.tabs::-webkit-scrollbar { display: none; }
.tab {
  flex: 1 0 auto; padding: 12px 16px; border: 0; background: none; color: var(--muted);
  font: inherit; font-size: 14px; font-weight: 600; cursor: pointer; white-space: nowrap;
  border-bottom: 2px solid transparent;
}
.tab[aria-selected="true"] { color: var(--accent); border-bottom-color: var(--accent); }
.tab:focus-visible { outline: 2px solid var(--accent); outline-offset: -2px; }

.panel { padding: 20px; }
.panel[hidden] { display: none; }
.fields { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
@media (max-width: 520px) { .fields { grid-template-columns: 1fr; } }
label { display: block; font-size: 14px; font-weight: 600; margin-bottom: 6px; }
.input { position: relative; }
.input input {
  width: 100%; padding: 12px 14px; font: inherit; font-size: 18px; color: var(--text);
  background: var(--bg); border: 1px solid var(--border); border-radius: 8px;
}
.input input:focus { outline: none; border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); }
.input.has-suffix input { padding-right: 36px; }
.input .suffix { position: absolute; right: 14px; top: 50%; transform: translateY(-50%); color: var(--muted); pointer-events: none; }
.hint { font-size: 13px; color: var(--muted); margin-top: 4px; }

.result {
  margin-top: 18px; padding: 18px; border-radius: 10px; background: var(--accent-soft);
  min-height: 92px;
}
.result .big { font-size: clamp(32px, 7vw, 44px); font-weight: 750; line-height: 1.1; font-variant-numeric: tabular-nums; }
.result .big.up { color: var(--up); }
.result .big.down { color: var(--down); }
.result .sentence { margin: 6px 0 0; }
.result.empty { background: var(--bg); color: var(--muted); display: flex; align-items: center; }
.result.error { background: var(--warn-bg); color: var(--warn-text); }
.note { margin-top: 10px; padding: 10px 12px; border-radius: 8px; background: var(--warn-bg); color: var(--warn-text); font-size: 14px; }
.extra { display: flex; flex-wrap: wrap; gap: 8px 20px; margin-top: 10px; font-size: 14px; color: var(--muted); }
.extra b { color: var(--text); font-variant-numeric: tabular-nums; }

details.steps { margin-top: 12px; font-size: 15px; }
details.steps summary { cursor: pointer; font-weight: 600; color: var(--accent); }
details.steps ol { margin: 8px 0 0; padding-left: 22px; font-variant-numeric: tabular-nums; }

.toolbar { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; padding: 12px 20px; border-top: 1px solid var(--border); font-size: 14px; }
.toolbar .spacer { flex: 1; }
.btn {
  font: inherit; font-size: 14px; padding: 7px 12px; border-radius: 8px; cursor: pointer;
  background: var(--surface); color: var(--text); border: 1px solid var(--border);
}
.btn:hover { border-color: var(--accent); }
.toolbar select { font: inherit; font-size: 14px; padding: 6px 8px; border-radius: 8px; border: 1px solid var(--border); background: var(--surface); color: var(--text); }

.chain-list { display: grid; gap: 8px; }
.chain-row { display: flex; gap: 8px; align-items: center; }
.chain-row .input { flex: 1; }
.chain-row .btn { padding: 10px 12px; }

/* ---- Content ---- */
article { margin: 36px 0; }
article h2 { font-size: 24px; line-height: 1.3; margin: 36px 0 10px; }
article h3 { font-size: 18px; margin: 24px 0 6px; }
.answer { border-left: 4px solid var(--accent); background: var(--surface); padding: 14px 16px; border-radius: 0 8px 8px 0; }
.formula { font-size: 18px; font-weight: 650; text-align: center; padding: 14px; background: var(--surface); border: 1px solid var(--border); border-radius: 8px; overflow-x: auto; }
.table-wrap { overflow-x: auto; }
table { width: 100%; border-collapse: collapse; font-size: 15px; font-variant-numeric: tabular-nums; }
th, td { text-align: left; padding: 9px 10px; border-bottom: 1px solid var(--border); white-space: nowrap; }
th { font-size: 13px; color: var(--muted); font-weight: 600; }
code, pre { font-family: ui-monospace, "Cascadia Code", Consolas, monospace; font-size: 14px; }
pre { background: var(--surface); border: 1px solid var(--border); border-radius: 8px; padding: 12px 14px; overflow-x: auto; }
.faq details { border-bottom: 1px solid var(--border); padding: 12px 0; }
.faq summary { cursor: pointer; font-weight: 600; }
.faq p { margin: 8px 0 0; }

.related { display: grid; grid-template-columns: repeat(auto-fill, minmax(210px, 1fr)); gap: 10px; }
.related a { display: block; padding: 12px 14px; background: var(--surface); border: 1px solid var(--border); border-radius: 10px; text-decoration: none; color: var(--text); font-weight: 600; font-size: 15px; }
.related a span { display: block; font-weight: 400; color: var(--muted); font-size: 13px; }
.related a:hover { border-color: var(--accent); }

.byline { font-size: 14px; color: var(--muted); }
footer { border-top: 1px solid var(--border); padding: 24px 0 40px; font-size: 14px; color: var(--muted); }
.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); }