/* ============================================================
   GODLY MUST — BLACK & WHITE STUDY ARCHIVE
   light theme · swiss grid · rtl arabic
   ============================================================ */

:root{
  --bg:#ffffff;
  --ink:#0a0a0a;
  --muted:#6f6f6f;
  --panel:#f6f6f4;
  --line:#0a0a0a;
  --line-soft:#e4e4e0;
  --sans:"IBM Plex Sans Arabic",system-ui,-apple-system,"Segoe UI",sans-serif;
  --mono:"IBM Plex Mono",ui-monospace,"SF Mono",monospace;
  --nav-h:64px;
  --ease:cubic-bezier(.22,.9,.28,1);
}

*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}

html{scroll-behavior:smooth}
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{animation-duration:.01ms!important;animation-iteration-count:1!important;transition-duration:.01ms!important}
}

body{
  font-family:var(--sans);
  background:var(--bg);
  color:var(--ink);
  line-height:1.75;
  -webkit-font-smoothing:antialiased;
  overflow-x:hidden;
}

::selection{background:var(--ink);color:var(--bg)}
::-webkit-scrollbar{width:10px}
::-webkit-scrollbar-track{background:var(--bg)}
::-webkit-scrollbar-thumb{background:var(--ink);border:2px solid var(--bg)}

a{color:inherit;text-decoration:none}
.mono{font-family:var(--mono);letter-spacing:.06em}

:focus-visible{outline:2px solid var(--ink);outline-offset:3px}

/* film grain */
.noise{
  position:fixed;inset:0;z-index:60;pointer-events:none;opacity:.05;
  background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='120' height='120'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2'/%3E%3C/filter%3E%3Crect width='120' height='120' filter='url(%23n)' opacity='1'/%3E%3C/svg%3E");
}

/* ============ NAV ============ */
.nav{
  position:fixed;top:0;right:0;left:0;z-index:50;
  height:var(--nav-h);
  display:flex;align-items:center;justify-content:space-between;
  padding-inline:clamp(16px,4vw,48px);
  background:rgba(255,255,255,.82);
  backdrop-filter:blur(12px);-webkit-backdrop-filter:blur(12px);
  border-bottom:1px solid var(--line);
}
.nav__logo{font-weight:600;font-size:15px;letter-spacing:.14em}
.nav__logo sup{font-size:9px}
.nav__links{display:flex;gap:clamp(14px,3vw,34px);font-size:16px;font-weight:500}
.nav__links a{position:relative;padding-block:4px}
.nav__links a::after{
  content:"";position:absolute;bottom:0;right:0;height:1.5px;width:0;
  background:var(--ink);transition:width .3s var(--ease);
}
.nav__links a:hover::after{width:100%}
.nav__cta{
  font-size:12px;font-weight:600;border:1.5px solid var(--ink);
  padding:8px 16px;transition:background .25s var(--ease),color .25s var(--ease);
}
.nav__cta:hover{background:var(--ink);color:var(--bg)}

/* ============ HERO ============ */
.hero{
  min-height:100svh;
  display:flex;flex-direction:column;justify-content:center;
  padding:calc(var(--nav-h) + 40px) clamp(16px,4vw,48px) 0;
  position:relative;
}
.hero__meta{
  display:flex;justify-content:space-between;gap:16px;flex-wrap:wrap;
  font-size:12.5px;text-transform:uppercase;color:var(--muted);
  border-bottom:1px solid var(--line-soft);padding-bottom:14px;
}
.hero__title{
  margin-block:clamp(28px,6vh,64px) clamp(20px,4vh,40px);
  font-weight:700;line-height:.92;letter-spacing:-.01em;
}
.hero__title .line{display:block;font-size:clamp(64px,15.5vw,220px)}
.hero__title .line--outline{
  color:transparent;
  -webkit-text-stroke:clamp(1.5px,.3vw,3.5px) var(--ink);
  transition:color .5s var(--ease);
  cursor:default;
}
.hero__title .line--outline:hover{color:var(--ink)}
.hero__title sup{font-size:.18em;-webkit-text-stroke:0;color:var(--ink);vertical-align:super}
.hero__sub{
  max-width:640px;font-size:clamp(18px,2.4vw,26px);color:#2b2b2b;font-weight:400;
}
.hero__sub-en{display:block;margin-top:10px;font-size:12.5px;color:var(--muted)}
.hero__cta{display:flex;gap:14px;flex-wrap:wrap;margin-top:clamp(24px,4vh,44px)}
.btn{
  display:inline-flex;align-items:center;gap:8px;
  border:1.5px solid var(--ink);padding:14px 28px;
  font-size:17px;font-weight:600;font-family:var(--sans);
  background:var(--bg);color:var(--ink);cursor:pointer;
  transition:background .25s var(--ease),color .25s var(--ease),transform .25s var(--ease);
}
.btn:hover{background:var(--ink);color:var(--bg);transform:translateY(-2px)}
.btn--solid{background:var(--ink);color:var(--bg)}
.btn--solid:hover{background:var(--bg);color:var(--ink)}
.hero__foot{
  margin-top:auto;
  display:flex;justify-content:space-between;gap:14px;flex-wrap:wrap;
  font-size:12.5px;color:var(--muted);
  border-top:1px solid var(--line-soft);
  padding-block:16px;
}

/* ============ MARQUEE ============ */
.marquee{
  background:var(--ink);color:var(--bg);
  overflow:hidden;white-space:nowrap;
  border-block:1px solid var(--ink);
  padding-block:14px;
}
.marquee__track{display:inline-flex;animation:slide 28s linear infinite}
.marquee__track span{font-size:17px;font-weight:600}
@keyframes slide{from{transform:translateX(0)}to{transform:translateX(-50%)}}

/* ============ STATS ============ */
.stats{
  display:grid;grid-template-columns:repeat(4,1fr);
  border-bottom:1px solid var(--line);
}
.stat{
  padding:clamp(24px,4vw,48px) clamp(16px,3vw,40px);
  border-inline-start:1px solid var(--line-soft);
  display:flex;flex-direction:column;gap:6px;
}
.stat:first-child{border-inline-start:none}
.stat__num{font-size:clamp(34px,5vw,64px);font-weight:600;line-height:1;font-variant-numeric:tabular-nums}
.stat__label{font-size:15px;color:var(--muted)}

/* ============ SECTIONS ============ */
.section{padding:clamp(56px,10vh,120px) clamp(16px,4vw,48px)}
.section__head{margin-bottom:clamp(32px,6vh,64px);position:relative}
.section__index{
  font-size:12px;color:var(--muted);
  display:block;margin-bottom:10px;
}
.section__title{
  font-size:clamp(34px,5.5vw,66px);font-weight:700;line-height:1.15;
  border-top:2px solid var(--ink);padding-top:18px;
}
.section__title .mono{font-size:.42em;font-weight:500;color:var(--muted);letter-spacing:.12em}
.section__hint{margin-top:10px;font-size:16.5px;color:var(--muted)}

/* ============ SUBJECTS (accordion) ============ */
.subjects{border-bottom:1px solid var(--line)}
.subject{border-top:1px solid var(--line)}
.subject__head{
  width:100%;background:none;border:0;cursor:pointer;font-family:inherit;color:inherit;
  display:grid;grid-template-columns:auto 1fr auto auto;align-items:center;gap:clamp(12px,3vw,36px);
  padding:clamp(20px,3.5vh,36px) clamp(8px,1.5vw,20px);
  text-align:start;
  transition:background .3s var(--ease),color .3s var(--ease);
}
.subject__head:hover,.subject.open .subject__head{background:var(--ink);color:var(--bg)}
.subject__head:hover .subject__meta,.subject.open .subject__meta{color:#bdbdbd}
.subject__head:hover .subject__en,.subject.open .subject__en{color:#8a8a8a}
.subject__num{font-family:var(--mono);font-size:12px;color:inherit;opacity:.55}
.subject__name{display:flex;flex-direction:column;gap:2px;min-width:0}
.subject__title{font-size:clamp(24px,3.8vw,40px);font-weight:700;line-height:1.25}
.subject__en{font-family:var(--mono);font-size:13px;letter-spacing:.14em;color:var(--muted)}
.subject__meta{font-size:15px;color:var(--muted);white-space:nowrap}
.subject__icon{
  font-family:var(--mono);font-size:22px;font-weight:600;line-height:1;
  width:44px;height:44px;border:1.5px solid currentColor;border-radius:50%;
  display:grid;place-items:center;flex-shrink:0;
  transition:transform .4s var(--ease);
}
.subject.open .subject__icon{transform:rotate(45deg)}

.subject__panel{
  display:grid;grid-template-rows:0fr;transition:grid-template-rows .5s var(--ease);
}
.subject.open .subject__panel{grid-template-rows:1fr}
.subject__panel-inner{overflow:hidden}
.subject__body{
  padding:clamp(20px,3vh,36px) clamp(8px,1.5vw,20px) clamp(28px,4vh,48px);
  display:grid;grid-template-columns:1fr 1.4fr;gap:clamp(20px,4vw,56px);
  background:var(--panel);border-top:1px solid var(--line-soft);
}
.subject__desc{font-size:18px;line-height:1.9}
.subject__teach{margin-top:14px;font-size:15px;color:var(--muted)}
.subject__tags{display:flex;flex-wrap:wrap;gap:8px;margin-top:16px}
.tag{
  font-family:var(--mono);font-size:12px;letter-spacing:.1em;text-transform:uppercase;
  border:1px solid var(--ink);padding:4px 10px;
}
.subject__lectures{list-style:none;border-top:1px solid var(--line)}
.lec{
  display:grid;grid-template-columns:auto 1fr auto;align-items:center;gap:16px;
  padding:13px 6px;border-bottom:1px solid var(--line-soft);
  transition:background .2s var(--ease),padding-inline-start .25s var(--ease);
}
.lec:hover{background:var(--bg);padding-inline-start:14px}
.lec__code{font-family:var(--mono);font-size:13px;color:var(--muted);white-space:nowrap}
.lec__title{font-size:18px;font-weight:600}
.lec__en{font-family:var(--mono);font-size:12px;color:var(--muted);letter-spacing:.08em;display:block}
.lec__type{
  font-family:var(--mono);font-size:12px;padding:5px 13px;white-space:nowrap;
  border:1px solid var(--ink);
}
.lec__type--lab{background:var(--ink);color:var(--bg)}

/* ============ METHOD (black section) ============ */
.section--black{background:var(--ink);color:var(--bg)}
.section--black .section__title{border-top-color:var(--bg)}
.section--black .section__index,.section--black .section__hint{color:#8f8f8f}
.section--black .section__title .mono{color:#8f8f8f}
.method{display:grid;grid-template-columns:repeat(3,1fr);border-inline-start:1px solid #333}
.method__col{
  padding:clamp(24px,3vw,44px);border-inline-end:1px solid #333;
  display:flex;flex-direction:column;gap:14px;
  transition:background .3s var(--ease);
}
.method__col:hover{background:#161616}
.method__num{font-size:12px;color:#8f8f8f}
.method__col h3{font-size:clamp(22px,2.6vw,30px);font-weight:700}
.method__col p{font-size:17px;line-height:1.9;color:#cfcfcf}
.method__col b{color:#fff}

/* ============ ABOUT ============ */
.about{display:grid;grid-template-columns:auto 1fr;gap:clamp(24px,5vw,72px);align-items:start}
.about__mark{
  width:clamp(110px,16vw,200px);aspect-ratio:1;
  background:var(--ink);color:var(--bg);
  display:grid;place-items:center;
  font-size:clamp(52px,8vw,104px);font-weight:600;
  user-select:none;
}
.about__lead{font-size:clamp(22px,3vw,32px);font-weight:600;line-height:1.6;margin-bottom:16px}
.about__body p:not(.about__lead){font-size:18px;line-height:1.95;color:#2b2b2b;max-width:640px}
.about__links{display:flex;gap:22px;margin-top:24px;font-size:14px}
.about__links a{border-bottom:1.5px solid var(--ink);padding-bottom:2px;transition:opacity .2s}
.about__links a:hover{opacity:.55}

/* ============ FOOTER ============ */
.footer{border-top:2px solid var(--ink);padding:clamp(32px,6vh,72px) clamp(16px,4vw,48px) 20px;overflow:hidden}
.footer__giant{
  font-size:clamp(44px,11.5vw,170px);font-weight:600;line-height:1;
  letter-spacing:.02em;white-space:nowrap;text-align:center;
  color:transparent;-webkit-text-stroke:1.5px var(--ink);
  transition:color .5s var(--ease);
}
.footer__giant:hover{color:var(--ink)}
.footer__bar{
  display:flex;justify-content:space-between;gap:12px;flex-wrap:wrap;
  border-top:1px solid var(--line-soft);margin-top:clamp(24px,5vh,56px);padding-top:16px;
  font-size:12.5px;color:var(--muted);
}
.footer__bw{color:var(--ink)}

/* ============ REVEAL ============ */
.reveal{opacity:0;transform:translateY(26px);transition:opacity .7s var(--ease),transform .7s var(--ease)}
.reveal.in{opacity:1;transform:none}

/* ============ RESPONSIVE ============ */
@media (max-width:900px){
  .method{grid-template-columns:1fr;border-inline-start:0;border-top:1px solid #333}
  .method__col{border-inline-end:0;border-bottom:1px solid #333}
  .subject__body{grid-template-columns:1fr}
  .stats{grid-template-columns:repeat(2,1fr)}
  .stat:nth-child(odd){border-inline-start:none}
  .stat:nth-child(n+3){border-top:1px solid var(--line-soft)}
}
@media (max-width:640px){
  .nav__links{display:none}
  .subject__head{grid-template-columns:auto 1fr auto}
  .subject__meta{display:none}
  .about{grid-template-columns:1fr}
  .footer__giant{white-space:normal}
}


/* ============ LECTURE PAGES ============ */
.docpage__subj{border-color:var(--ink);pointer-events:none}
.doc__head{max-width:980px;margin:0 auto;padding:calc(var(--nav-h) + 48px) clamp(16px,4vw,48px) 30px;border-bottom:2px solid var(--ink)}
.doc__meta{display:flex;gap:12px;align-items:center;flex-wrap:wrap;margin-bottom:20px}
.doc__code{font-size:13px;font-weight:600;border:1.5px solid var(--ink);padding:7px 16px;letter-spacing:.1em}
.doc__type{font-size:13px;font-weight:600;padding:7px 16px;border:1.5px solid var(--ink)}
.doc__type--lab{background:var(--ink);color:var(--bg)}
.doc__title{font-size:clamp(30px,5vw,54px);font-weight:700;line-height:1.3}
.doc__en{margin-top:12px;font-size:14px;color:var(--muted);letter-spacing:.12em}
.doc__teach{margin-top:16px;font-size:16px;color:var(--muted)}
.doc{max-width:980px;margin:0 auto;padding:16px clamp(16px,4vw,48px) 40px}
.doc .para{font-size:19px;line-height:2.05;margin-block:18px;color:#1a1a1a}
.doc-h2{font-size:clamp(26px,3.4vw,36px);font-weight:700;margin-block:48px 16px;padding-top:24px;border-top:2px solid var(--ink)}
.doc-h3{font-size:clamp(22px,2.8vw,29px);font-weight:700;margin-block:38px 12px}
.doc-h4{font-size:clamp(18px,2.2vw,22px);font-weight:700;margin-block:28px 10px}
.lst{margin-block:16px;padding-inline-start:28px;font-size:18px;line-height:1.95}
.lst li{margin-block:8px;padding-inline-start:6px}
.lst--num li::marker{font-family:var(--mono);font-weight:600}
.rule{border:none;border-top:1px solid var(--line-soft);margin-block:34px}
.callout{display:flex;gap:16px;background:var(--panel);border:1.5px solid var(--ink);padding:22px 24px;margin-block:26px;font-size:18px;line-height:1.95}
.callout__icon{font-size:26px;flex-shrink:0}
.callout__body{flex:1;min-width:0}
.callout__body .para{margin-block:8px;font-size:inherit}
.tg{border:1.5px solid var(--ink);margin-block:16px;background:var(--bg)}
.tg summary{cursor:pointer;list-style:none;display:flex;justify-content:space-between;align-items:center;gap:12px;padding:17px 22px;font-size:18px;font-weight:600;transition:background .25s var(--ease),color .25s var(--ease)}
.tg summary::-webkit-details-marker{display:none}
.tg summary:hover{background:var(--ink);color:var(--bg)}
.tg[open] summary{background:var(--ink);color:var(--bg);border-bottom:1.5px solid var(--ink)}
.tg__plus{font-family:var(--mono);font-size:24px;line-height:1;flex-shrink:0;transition:transform .3s var(--ease)}
.tg[open] .tg__plus{transform:rotate(45deg)}
.tg__body{padding:20px 24px}
.tg__body .para{font-size:17.5px}
.tg .tg{margin-block:10px}
.tbl-wrap{overflow-x:auto;margin-block:26px}
.tbl{width:100%;border-collapse:collapse;font-size:17px;border:1.5px solid var(--ink)}
.tbl th{background:var(--ink);color:var(--bg);font-weight:600;padding:14px 18px;text-align:start}
.tbl td{padding:13px 18px;border-top:1px solid var(--line-soft);line-height:1.85}
.tbl tr:nth-child(even) td{background:#fafaf8}
.code{background:var(--ink);color:#f5f5f5;padding:24px 26px;margin-block:26px;overflow-x:auto;font-size:16px;line-height:1.8;border:1.5px solid var(--ink)}
.code code{font-family:var(--mono);background:none;color:inherit;padding:0;font-size:inherit}
p code,li code,td code,summary code{font-family:var(--mono);background:#eeece8;padding:2px 8px;font-size:.88em;direction:ltr;unicode-bidi:embed}
.math-tex{direction:ltr;unicode-bidi:isolate;padding:0 3px}
.math-tex--display{display:block;overflow-x:auto;padding:22px 18px;border:1.5px solid var(--ink);background:var(--bg);margin-block:26px;text-align:center;font-size:20px}
.math-tex--display .katex{font-size:1.12em}
.katex{direction:ltr}
.fig{margin-block:30px;border:1.5px solid var(--ink);background:var(--bg)}
.fig img{display:block;width:100%;height:auto}
.fig figcaption{border-top:1.5px solid var(--ink);padding:13px 18px;font-size:14.5px;color:var(--muted)}
.doc__pager{max-width:980px;margin:0 auto;padding:0 clamp(16px,4vw,48px) 80px;display:flex;justify-content:space-between;align-items:center;gap:14px;flex-wrap:wrap}
.footer--mini{margin-top:0}
/* صف المحاضرة كرابط */
a.lec{color:inherit}
.lec__title::after{content:" ←";opacity:0;transition:opacity .2s;font-weight:400;font-family:var(--mono);font-size:.8em}
.lec:hover .lec__title::after{opacity:.55}
@media (max-width:640px){
  .doc .para{font-size:17.5px}
  .callout{font-size:16.5px}
  .lst{font-size:16.5px}
  .doc__pager{justify-content:center}
}