:root {
  --bg: #f5f7f6;
  --surface: #ffffff;
  --surface-2: #eef2f1;
  --text: #15201e;
  --muted: #5a6865;
  --border: #dde4e2;
  --accent: #0b7a6e;
  --accent-strong: #075e55;
  --accent-soft: #e2f3f0;
  --warn: #b45309;
  --shadow: 0 1px 2px rgba(16, 40, 36, .06), 0 8px 24px rgba(16, 40, 36, .06);
  --radius: 16px;
  --font: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", "Noto Sans Arabic", Tahoma, sans-serif;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0e1413;
    --surface: #161e1c;
    --surface-2: #1d2725;
    --text: #e6edeb;
    --muted: #9aaba7;
    --border: #2a3633;
    --accent: #36b3a2;
    --accent-strong: #5cc9b9;
    --accent-soft: #15302c;
    --warn: #f0a54a;
    --shadow: 0 1px 2px rgba(0, 0, 0, .3), 0 8px 24px rgba(0, 0, 0, .25);
    color-scheme: dark;
  }
}

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0; background: var(--bg); color: var(--text);
  font: 16px/1.6 var(--font);
  -webkit-font-smoothing: antialiased;
}
[dir="rtl"] body { line-height: 1.8; }
img, svg { max-width: 100%; }
a { color: var(--accent-strong); }
a:hover { color: var(--accent); }
h1, h2, h3 { line-height: 1.25; letter-spacing: -.01em; }
[hidden] { display: none !important; }
.sr { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.skip { position: absolute; inset-inline-start: 8px; top: -60px; background: var(--accent); color: #fff; padding: 8px 14px; border-radius: 8px; z-index: 20; }
.skip:focus { top: 8px; }
:focus-visible { outline: 3px solid color-mix(in srgb, var(--accent) 55%, transparent); outline-offset: 2px; }

.wrap { max-width: 1120px; margin: 0 auto; padding-inline: 20px; }
.wrap.narrow { max-width: 820px; }
@media (max-width: 480px) { .wrap { padding-inline: 16px; } }

/* header */
.site-header { background: var(--surface); border-bottom: 1px solid var(--border); position: sticky; top: 0; z-index: 10; }
.bar { display: flex; align-items: center; justify-content: space-between; gap: 12px; min-height: 60px; }
.brand { display: inline-flex; align-items: center; gap: 10px; color: var(--text); text-decoration: none; font-weight: 750; font-size: 1.15rem; letter-spacing: -.02em; }
.brand:hover { color: var(--text); }
.brand .logo { flex: none; }
.langs { position: relative; }
.langs summary { list-style: none; cursor: pointer; display: inline-flex; align-items: center; gap: 6px; padding: 7px 12px; border: 1px solid var(--border); border-radius: 999px; font-size: .92rem; color: var(--muted); user-select: none; }
.langs summary::-webkit-details-marker { display: none; }
.langs summary:hover { color: var(--text); border-color: var(--muted); }
.langs ul { position: absolute; inset-inline-end: 0; top: calc(100% + 8px); margin: 0; padding: 6px; list-style: none; background: var(--surface); border: 1px solid var(--border); border-radius: 12px; box-shadow: var(--shadow); min-width: 170px; }
.langs li a { display: block; padding: 8px 12px; border-radius: 8px; color: var(--text); text-decoration: none; }
.langs li a:hover { background: var(--surface-2); }
.langs li a[aria-current] { background: var(--accent-soft); color: var(--accent-strong); font-weight: 650; }

/* home */
.hero { background: linear-gradient(180deg, var(--accent-soft), var(--bg)); padding-block: 56px 36px; text-align: center; }
.hero h1 { font-size: clamp(1.8rem, 4.5vw, 2.8rem); margin: 0 0 10px; font-weight: 800; }
.hero p { margin: 0 auto; max-width: 620px; color: var(--muted); font-size: 1.08rem; }
.search { position: relative; max-width: 560px; margin: 28px auto 0; }
.search svg { position: absolute; inset-inline-start: 16px; top: 50%; transform: translateY(-50%); color: var(--muted); pointer-events: none; }
.search input { width: 100%; height: 54px; border-radius: 999px; border: 1px solid var(--border); background: var(--surface); color: var(--text); font: inherit; font-size: 1.05rem; padding-inline: 48px 20px; box-shadow: var(--shadow); }
.search input:focus { outline: none; border-color: var(--accent); }
.hero .count { font-size: .9rem; margin-top: 14px; }
.cat { margin-block: 34px; }
.cat h2 { font-size: 1.2rem; margin: 0 0 14px; }
.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(250px, 1fr)); gap: 12px; }
.card { display: flex; gap: 14px; align-items: flex-start; padding: 16px; background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); color: var(--text); text-decoration: none; transition: border-color .15s, transform .15s, box-shadow .15s; }
.card:hover { color: var(--text); border-color: var(--accent); transform: translateY(-1px); box-shadow: var(--shadow); }
.card .ico { flex: none; width: 42px; height: 42px; border-radius: 12px; display: grid; place-items: center; background: var(--accent-soft); color: var(--accent-strong); }
.card-text { display: flex; flex-direction: column; min-width: 0; }
.card strong { font-weight: 650; line-height: 1.35; }
.card small { color: var(--muted); font-size: .88rem; line-height: 1.45; margin-top: 2px; }
.noresults { text-align: center; color: var(--muted); padding: 30px 0; }
.why { margin-block: 56px 40px; padding: 28px; background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); }
.why h2 { margin: 0 0 16px; font-size: 1.25rem; }
.why-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 20px; }
.why h3 { margin: 0 0 4px; font-size: 1rem; color: var(--accent-strong); }
.why p { margin: 0; color: var(--muted); }

/* tool page */
.crumbs { display: flex; flex-wrap: wrap; gap: 8px; font-size: .9rem; color: var(--muted); padding-top: 22px; }
.crumbs a { color: var(--muted); text-decoration: none; }
.crumbs a:hover { color: var(--accent-strong); text-decoration: underline; }
[dir="rtl"] .crumbs span { transform: scaleX(-1); display: inline-block; }
main h1 { font-size: clamp(1.6rem, 4vw, 2.2rem); margin: 10px 0 8px; font-weight: 800; }
.lead { color: var(--muted); font-size: 1.07rem; margin: 0 0 22px; }

.tool { background: var(--surface); border: 1px solid var(--border); border-radius: 20px; padding: 24px; box-shadow: var(--shadow); }
@media (max-width: 480px) { .tool { padding: 18px 16px; border-radius: 16px; } }
.tool > * + * { margin-top: 18px; }
.tool h2 { font-size: 1.05rem; margin: 0; }
.fields { display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); gap: 14px 16px; }
.field { display: flex; flex-direction: column; gap: 6px; min-width: 0; }
.field.wide { grid-column: 1 / -1; }
.field label, .label { font-weight: 600; font-size: .93rem; }
.input { position: relative; display: flex; align-items: stretch; }
.input input, .input select, textarea {
  width: 100%; min-width: 0; height: 48px; border: 1px solid var(--border); border-radius: 12px;
  background: var(--bg); color: var(--text); font: inherit; font-size: 1.05rem; padding-inline: 14px;
  font-variant-numeric: tabular-nums; transition: border-color .15s, box-shadow .15s;
}
.input select { appearance: none; background-image: linear-gradient(45deg, transparent 50%, var(--muted) 50%), linear-gradient(135deg, var(--muted) 50%, transparent 50%); background-position: calc(100% - 20px) 21px, calc(100% - 15px) 21px; background-size: 5px 5px; background-repeat: no-repeat; padding-inline-end: 36px; }
[dir="rtl"] .input select { background-position: 15px 21px, 20px 21px; }
.input input:focus, .input select:focus, textarea:focus { outline: none; border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); background: var(--surface); }
.input.has-suffix input { padding-inline-end: 58px; }
.suffix { position: absolute; inset-inline-end: 1px; top: 1px; bottom: 1px; display: grid; place-items: center; padding-inline: 12px; color: var(--muted); font-size: .92rem; pointer-events: none; }
input[type="date"] { padding-inline: 10px; }
textarea { height: auto; min-height: 220px; padding: 12px 14px; line-height: 1.6; resize: vertical; display: block; }
.hint { color: var(--muted); font-size: .83rem; line-height: 1.4; }
.check { display: inline-flex; align-items: center; gap: 10px; cursor: pointer; font-size: .95rem; }
.check input { width: 20px; height: 20px; accent-color: var(--accent); margin: 0; }

.seg { display: inline-flex; flex-wrap: wrap; gap: 4px; padding: 4px; background: var(--surface-2); border-radius: 14px; max-width: 100%; }
.seg label { cursor: pointer; }
.seg input { position: absolute; opacity: 0; pointer-events: none; }
.seg span { display: block; padding: 8px 14px; border-radius: 10px; font-size: .93rem; font-weight: 600; color: var(--muted); }
.seg input:checked + span { background: var(--surface); color: var(--accent-strong); box-shadow: 0 1px 3px rgba(0, 0, 0, .12); }
.seg input:focus-visible + span { outline: 3px solid var(--accent-soft); }

.chips { display: flex; flex-wrap: wrap; gap: 8px; }
.chip { font: inherit; font-size: .86rem; padding: 6px 12px; border-radius: 999px; border: 1px solid var(--border); background: var(--bg); color: var(--text); cursor: pointer; }
.chip:hover { border-color: var(--accent); }
.chip.on { background: var(--accent-soft); border-color: var(--accent); color: var(--accent-strong); font-weight: 600; }

.result { background: var(--accent-soft); border-radius: 14px; padding: 16px 18px; }
.result .empty { color: var(--muted); margin: 0; }
.result .msg { margin: 0; color: var(--warn); font-weight: 600; }
.rows { margin: 0; display: grid; gap: 2px; }
.row { display: flex; justify-content: space-between; align-items: baseline; gap: 16px; padding: 7px 0; border-bottom: 1px dashed color-mix(in srgb, var(--accent) 22%, transparent); }
.row:last-child { border-bottom: 0; }
.row dt { color: var(--muted); }
.row dd { margin: 0; font-weight: 700; font-variant-numeric: tabular-nums; text-align: end; }
.row.big dt { color: var(--text); font-weight: 600; }
.row.big dd { font-size: 1.6rem; color: var(--accent-strong); line-height: 1.2; }
.result .note { margin: 10px 0 0; font-size: .9rem; color: var(--muted); }
.result table { margin-top: 8px; }

.sentence { display: flex; flex-wrap: wrap; align-items: center; gap: 8px 10px; padding: 16px 0; border-bottom: 1px solid var(--border); }
.sentence:last-of-type { border-bottom: 0; }
.tool .sentence + .sentence { margin-top: 0; }
.sentence .inline { width: 110px; height: 44px; border: 1px solid var(--border); border-radius: 10px; background: var(--bg); color: var(--text); font: inherit; font-size: 1.02rem; padding-inline: 10px; text-align: center; font-variant-numeric: tabular-nums; }
.sentence .inline:focus { outline: none; border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); }
.sentence select { height: 44px; border: 1px solid var(--border); border-radius: 10px; background: var(--bg); color: var(--text); font: inherit; padding-inline: 8px; }
.sentence .ans { margin-inline-start: auto; background: var(--accent-soft); color: var(--accent-strong); font-weight: 750; padding: 8px 14px; border-radius: 10px; min-width: 90px; text-align: center; font-variant-numeric: tabular-nums; }
@media (max-width: 560px) { .sentence .ans { margin-inline-start: 0; width: 100%; } .sentence .inline { width: 84px; } }

.scale { position: relative; height: 12px; border-radius: 99px; margin: 26px 0 6px; background: linear-gradient(90deg, #60a5fa 0 14%, #34d399 14% 40%, #fbbf24 40% 60%, #f97316 60% 80%, #ef4444 80%); }
[dir="rtl"] .scale { transform: scaleX(-1); }
.scale i { position: absolute; top: -7px; width: 4px; height: 26px; border-radius: 2px; background: var(--text); transform: translateX(-50%); box-shadow: 0 0 0 2px var(--surface); }

.private { display: flex; gap: 8px; align-items: flex-start; font-size: .88rem; color: var(--muted); margin: 12px 4px 0; }
.private svg { flex: none; margin-top: 3px; }

.content { margin-top: 36px; }
.content h2 { font-size: 1.35rem; margin: 34px 0 10px; }
.content h3 { font-size: 1.08rem; margin: 22px 0 6px; }
.content p, .content li { max-width: 72ch; }
.content ol, .content ul { padding-inline-start: 1.4em; }
.content li + li { margin-top: 6px; }
.formula { background: var(--surface); border: 1px solid var(--border); border-inline-start: 4px solid var(--accent); border-radius: 10px; padding: 12px 16px; font-weight: 600; margin: 12px 0; overflow-x: auto; }
.example { background: var(--surface-2); border-radius: 12px; padding: 14px 18px; margin: 14px 0; }
.example p { margin: 4px 0; }
.table-wrap { overflow-x: auto; margin: 12px 0; }
table { border-collapse: collapse; width: 100%; font-size: .95rem; font-variant-numeric: tabular-nums; }
th, td { text-align: start; padding: 8px 10px; border-bottom: 1px solid var(--border); white-space: nowrap; }
th { font-weight: 650; color: var(--muted); font-size: .88rem; }

.faq { margin-top: 40px; }
.faq h2 { font-size: 1.35rem; margin: 0 0 8px; }
.faq details { border-bottom: 1px solid var(--border); }
.faq summary { cursor: pointer; list-style: none; padding: 14px 32px 14px 0; font-weight: 650; position: relative; }
[dir="rtl"] .faq summary { padding: 14px 0 14px 32px; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; position: absolute; inset-inline-end: 4px; top: 10px; font-size: 1.4rem; font-weight: 400; color: var(--accent); transition: transform .2s; }
.faq details[open] summary::after { transform: rotate(45deg); }
.faq details > div { padding: 0 0 14px; color: var(--muted); }
.faq details > div p { margin: 0 0 8px; }

.related { margin-top: 44px; }
.related h2 { font-size: 1.2rem; margin: 0 0 14px; }
.updated { color: var(--muted); font-size: .85rem; margin: 30px 0 40px; }

/* footer */
.site-footer { margin-top: 56px; border-top: 1px solid var(--border); background: var(--surface); padding-block: 28px; font-size: .93rem; }
.foot-top { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 18px; align-items: flex-start; }
.foot-brand p { margin: 6px 0 0; color: var(--muted); }
.foot-links, .foot-langs { display: flex; flex-wrap: wrap; gap: 8px 18px; }
.foot-links a, .foot-langs a { color: var(--text); text-decoration: none; }
.foot-links a:hover, .foot-langs a:hover { color: var(--accent-strong); text-decoration: underline; }
.foot-langs { margin: 14px 0; padding-top: 14px; border-top: 1px solid var(--border); }
.small { color: var(--muted); font-size: .85rem; margin: 14px 0 0; }

/* root chooser + 404 */
.root { min-height: 100vh; display: grid; place-items: center; background: linear-gradient(180deg, var(--accent-soft), var(--bg) 60%); }
.chooser { width: 100%; max-width: 520px; padding-block: 40px; text-align: center; }
.brand.big { font-size: 2rem; gap: 14px; margin-bottom: 28px; }
.brand.big .logo { width: 48px; height: 48px; }
.lang-list { display: grid; gap: 10px; }
.lang-choice { display: flex; justify-content: space-between; align-items: center; gap: 12px; padding: 16px 20px; background: var(--surface); border: 1px solid var(--border); border-radius: 14px; color: var(--text); text-decoration: none; text-align: start; }
.lang-choice:hover { border-color: var(--accent); color: var(--text); }
.lang-choice strong { font-size: 1.1rem; }
.lang-choice span { color: var(--muted); font-size: .92rem; }
.lang-choice.suggested { border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); }
.big404 { font-size: 3rem; font-weight: 800; color: var(--accent); margin: -10px 0 18px; }
@media (max-width: 420px) { .lang-choice { flex-direction: column; align-items: flex-start; gap: 2px; } }

/* rule of three grid */
.r3 { display: grid; grid-template-columns: 1fr auto 1fr; gap: 10px 12px; align-items: center; max-width: 520px; }
.r3 .inline { width: 100%; height: 48px; border: 1px solid var(--border); border-radius: 12px; background: var(--bg); color: var(--text); font: inherit; font-size: 1.05rem; padding-inline: 12px; text-align: center; font-variant-numeric: tabular-nums; }
.r3 .inline:focus { outline: none; border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); }
.r3-head { font-weight: 600; font-size: .9rem; color: var(--muted); text-align: center; }
.r3-arrow { color: var(--accent); font-size: 1.3rem; font-weight: 700; }
[dir="rtl"] .r3-arrow { transform: scaleX(-1); }
.r3 .ans { margin: 0; height: 48px; display: grid; place-items: center; background: var(--accent-soft); color: var(--accent-strong); font-weight: 750; border-radius: 12px; font-variant-numeric: tabular-nums; }

/* collapsible table inside results */
.result details { margin-top: 12px; }
.result summary { cursor: pointer; font-weight: 650; color: var(--accent-strong); }
.result .table-wrap { background: var(--surface); border-radius: 10px; padding: 4px 8px; }
.sources { margin-top: 34px; }
.sources h2 { font-size: 1.1rem; margin: 0 0 8px; }
.sources ul { margin: 0; padding-inline-start: 1.2em; color: var(--muted); font-size: .93rem; }

/* embed */
.embed-box { margin-top: 34px; padding: 18px 20px; background: var(--surface); border: 1px dashed var(--border); border-radius: var(--radius); }
.embed-box h2 { font-size: 1.1rem; margin: 0 0 4px; }
.embed-box p { margin: 0 0 10px; color: var(--muted); font-size: .93rem; }
.embed-code { min-height: 0; height: auto; font: .8rem/1.5 ui-monospace, SFMono-Regular, Menlo, monospace; direction: ltr; text-align: left; margin-bottom: 10px; }
body.embed { background: var(--bg); padding: 8px; }
body.embed .tool { box-shadow: none; }
.embed-credit { text-align: center; font-size: .85rem; margin: 8px 0 0; }