/* Layout: a calm instrument panel. A home index of calculators, each opens into a focused worksheet with explanation beside it. */
:root{
  --bg:#F3F6F5; --surface:#FFFFFF; --ink:#13302B; --muted:#5A6E69; --line:#D7E1DE;
  --accent:#0F6B5C; --accent-soft:#E2F0EC; --copper:#A8521F; --warn-bg:#FBF0E6; --warn-line:#E7C4A6;
  --f-display:"El Messiri","IBM Plex Sans Arabic",Tahoma,sans-serif;
  --f-body:"IBM Plex Sans Arabic",Tahoma,"Segoe UI",sans-serif;
}
@media (prefers-color-scheme:dark){:root:not([data-theme="light"]){
  --bg:#0E1716; --surface:#152220; --ink:#E4EEEB; --muted:#9AB0AA; --line:#2A3B38;
  --accent:#4FC2AA; --accent-soft:#183531; --copper:#E39565; --warn-bg:#2A1F17; --warn-line:#5C3C26; color-scheme:dark}}
:root[data-theme="dark"]{
  --bg:#0E1716; --surface:#152220; --ink:#E4EEEB; --muted:#9AB0AA; --line:#2A3B38;
  --accent:#4FC2AA; --accent-soft:#183531; --copper:#E39565; --warn-bg:#2A1F17; --warn-line:#5C3C26; color-scheme:dark}
*{box-sizing:border-box}
body{background:var(--bg);color:var(--ink);font-family:var(--f-body);font-size:16px;line-height:1.75;direction:rtl}
.wrap{max-width:1100px;margin:0 auto;padding-inline:16px;padding-block:0 48px}
header.site{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:12px;padding-block:20px;border-bottom:1px solid var(--line)}
.brand{display:flex;align-items:baseline;gap:10px;text-decoration:none;color:var(--ink)}
.brand b{font-family:var(--f-display);font-size:2rem;line-height:1;color:var(--accent)}
.brand span{color:var(--muted);font-size:.9rem}
nav.top a{color:var(--muted);text-decoration:none;font-size:.95rem}
nav.top a:hover{color:var(--accent)}
h1,h2,h3{font-family:var(--f-display);text-wrap:balance;line-height:1.35;margin:0}
.hero{padding-block:36px 20px;display:grid;gap:14px}
.hero h1{font-size:clamp(1.7rem,4vw,2.5rem)}
.hero p{margin:0;color:var(--muted);max-width:62ch}
.search{max-width:460px}
input,select{font:inherit;color:var(--ink);background:var(--surface);border:1px solid var(--line);border-radius:8px;padding:10px 12px;width:100%;min-width:0}
input:focus-visible,select:focus-visible,button:focus-visible,a:focus-visible{outline:2px solid var(--accent);outline-offset:2px}
.cats{display:flex;flex-wrap:wrap;gap:8px}
.chip{font:inherit;font-size:.88rem;border:1px solid var(--line);background:var(--surface);color:var(--muted);border-radius:99px;padding:4px 14px;cursor:pointer}
.chip[aria-pressed="true"]{background:var(--accent);border-color:var(--accent);color:var(--surface)}
.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(240px,1fr));gap:14px;margin-top:22px}
.card{display:grid;gap:6px;align-content:start;text-decoration:none;color:var(--ink);background:var(--surface);border:1px solid var(--line);border-radius:12px;padding:18px;transition:border-color .15s,transform .15s}
.card:hover{border-color:var(--accent);transform:translateY(-2px)}
.card .sym{font-family:var(--f-display);font-size:1.4rem;color:var(--copper);line-height:1}
.card h3{font-size:1.15rem}
.card p{margin:0;color:var(--muted);font-size:.92rem;line-height:1.6}
.card small{color:var(--accent);font-weight:600;font-size:.8rem}
.empty{color:var(--muted);padding:20px 0}
/* Calculator view */
.crumb{padding-block:18px 0;font-size:.9rem}
.crumb a{color:var(--accent);text-decoration:none}
.calc{display:grid;grid-template-columns:minmax(0,1.15fr) minmax(0,1fr);gap:28px;padding-block:18px}
@media (max-width:820px){.calc{grid-template-columns:1fr}}
.calc h2{font-size:clamp(1.5rem,3.5vw,2rem);margin-bottom:6px}
.lead{color:var(--muted);margin:0 0 16px}
.panel{background:var(--surface);border:1px solid var(--line);border-radius:12px;padding:20px;display:grid;gap:14px}
.row{display:grid;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));gap:12px}
label{display:grid;gap:4px;font-size:.9rem;font-weight:500;min-width:0}
label .hint{font-weight:400;color:var(--muted);font-size:.8rem}
.result{border-top:1px dashed var(--line);padding-top:14px;display:grid;gap:8px}
.big{font-family:var(--f-display);font-size:clamp(1.6rem,4vw,2.2rem);color:var(--accent);line-height:1.3;font-variant-numeric:tabular-nums}
.kv{display:grid;grid-template-columns:1fr auto;gap:4px 16px;font-size:.95rem}
.kv dt{color:var(--muted)} .kv dd{margin:0;font-weight:600;font-variant-numeric:tabular-nums}
.tag{display:inline-block;font-size:.85rem;font-weight:600;padding:2px 10px;border-radius:99px;background:var(--accent-soft);color:var(--accent)}
.tag.no{background:var(--warn-bg);color:var(--copper)}
.about h3{font-size:1.15rem;margin:18px 0 6px}
.about h3:first-child{margin-top:0}
.about p,.about li{color:var(--ink);max-width:65ch}
.about ul{padding-inline-start:20px;margin:0}
.note{background:var(--warn-bg);border:1px solid var(--warn-line);border-radius:10px;padding:14px 16px;font-size:.95rem}
.note b{color:var(--copper)}
.check{display:flex;gap:8px;align-items:flex-start;font-weight:500}
.check input{width:auto;margin-top:6px}
.tabs{display:flex;flex-wrap:wrap;gap:6px}
footer{border-top:1px solid var(--line);margin-top:40px;padding-top:18px;color:var(--muted);font-size:.85rem}
@media (prefers-reduced-motion:reduce){.card{transition:none}.card:hover{transform:none}}

.faq{margin-top:28px;display:grid;gap:10px;max-width:760px}
.faq h2{font-size:1.4rem;margin-bottom:4px}
.faq details{background:var(--surface);border:1px solid var(--line);border-radius:10px;padding:12px 16px}
.faq summary{cursor:pointer;font-weight:600}
.faq p{margin:8px 0 0;color:var(--muted)}
.related{margin-top:32px}
.related h2{font-size:1.3rem;margin-bottom:10px}
.page{max-width:760px;padding-block:28px}
.page h1{font-size:2rem;margin-bottom:12px}
.page h2{font-size:1.25rem;margin:22px 0 6px}
footer nav{display:flex;flex-wrap:wrap;gap:16px;margin-top:8px}
footer a{color:var(--muted)}