/* ============ Tasarim degiskenleri ============ */
:root{
  --bg:#f5f6fb; --surface:#ffffff; --surface-2:#f0f2f9; --line:#e3e6f1;
  --ink:#101228; --ink-2:#4d5270; --ink-3:#626984;
  --brand:#4a37f2; --brand-soft:#eeecff; --accent:#ff7a3c; --ok:#12a67a;
  --radius:20px; --radius-sm:12px;
  --shadow-1:0 1px 2px rgba(16,20,50,.06);
  --shadow-2:0 18px 40px -22px rgba(16,20,50,.45);
  --rail:268px; --wrap:1220px;
  --ui:system-ui,-apple-system,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;
  --serif:Georgia,"Times New Roman",serif;
}
[data-theme="dark"]{
  --bg:#0b0d1a; --surface:#12152a; --surface-2:#181c34; --line:#252a45;
  --ink:#eef0fb; --ink-2:#bdc3dc; --ink-3:#a0a7c2;
  --brand:#8b7bff; --brand-soft:#1d1f45;
  --shadow-2:0 18px 40px -22px rgba(0,0,0,.8);
}
*,*::before,*::after{box-sizing:border-box}
html{scroll-behavior:smooth;scroll-padding-top:96px;-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg);color:var(--ink);font-family:var(--ui);font-size:16px;line-height:1.65;
  -webkit-font-smoothing:antialiased}
img{max-width:100%;height:auto;display:block}
a{color:inherit;text-decoration:none}
button{font:inherit;cursor:pointer}
.screen-reader-text{position:absolute!important;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}
.skip{position:absolute;left:-9999px;top:0;background:var(--brand);color:#fff;padding:12px 18px;z-index:999}
.skip:focus{left:12px;top:12px;border-radius:10px}

/* ============ Okuma ilerlemesi ============ */
.progress{position:fixed;inset:0 0 auto 0;height:3px;z-index:80;pointer-events:none}
.progress span{display:block;height:100%;width:0;background:linear-gradient(90deg,var(--brand),var(--accent));transition:width .1s linear}

/* ============ Iskelet ============ */
.layout{display:flex;min-height:100vh}
.shell{flex:1;min-width:0;display:flex;flex-direction:column}
.main{flex:1;width:100%;max-width:var(--wrap);margin:0 auto;padding:28px 28px 80px}

/* ============ Sol ray ============ */
.rail{width:var(--rail);flex:0 0 var(--rail);position:sticky;top:0;height:100vh;
  background:var(--surface);border-right:1px solid var(--line);display:flex;flex-direction:column;z-index:60}
.rail__head{display:flex;align-items:center;justify-content:space-between;gap:8px;padding:20px 18px}
.brand{display:flex;align-items:center;gap:10px}
.brand__mark{width:38px;height:38px;border-radius:12px;display:grid;place-items:center;font-weight:800;font-size:14px;
  color:#fff;background:linear-gradient(140deg,var(--brand),#9b6bff)}
.brand__text strong{display:block;font-size:15px;font-weight:800;letter-spacing:-.2px}
.brand__text em{display:block;font-style:normal;font-size:11px;color:var(--ink-3);
  overflow:hidden;text-overflow:ellipsis;white-space:nowrap;max-width:170px}
.rail__close{display:none;background:none;border:0;font-size:26px;color:var(--ink-2);line-height:1}
.rail__nav{flex:1;overflow-y:auto;padding:4px 12px 20px;scrollbar-width:thin}
.rail__label{margin:12px 8px 8px;font-size:11px;letter-spacing:.12em;text-transform:uppercase;color:var(--ink-3);font-weight:700}
.rail__list,.rail__sub{list-style:none;margin:0;padding:0}
.rail__sub{margin-left:18px;border-left:1px solid var(--line);padding-left:8px}
.rail__link{display:flex;align-items:center;gap:10px;padding:9px 10px;border-radius:12px;
  font-size:14px;font-weight:600;color:var(--ink-2);transition:background .15s,color .15s}
.rail__link:hover{background:var(--surface-2);color:var(--ink)}
.rail__link.is-active{background:var(--brand-soft);color:var(--brand)}
.rail__spark{width:6px;height:6px;border-radius:50%;background:currentColor;opacity:.45;flex:none}
.rail__text{flex:1;min-width:0;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.rail__count{font-size:11px;color:var(--ink-3);font-weight:700}
.rail__foot{padding:14px;border-top:1px solid var(--line)}
.streak{background:var(--surface-2);border-radius:var(--radius-sm);padding:12px 14px}
.streak__label{margin:0 0 4px;font-size:11px;text-transform:uppercase;letter-spacing:.1em;color:var(--ink-3);font-weight:700}
.streak__link{font-size:13px;font-weight:700;color:var(--ink)}
.streak__link:hover{color:var(--brand)}

/* ============ Ust bar ============ */
.topbar{position:sticky;top:0;z-index:50;display:flex;align-items:center;gap:12px;
  padding:12px 28px;background:color-mix(in srgb,var(--bg) 85%,transparent);
  backdrop-filter:saturate(160%) blur(12px);border-bottom:1px solid var(--line)}
.topbar__menu{display:none;flex-direction:column;gap:4px}
.topbar__menu span{width:18px;height:2px;background:currentColor;border-radius:2px}
.icon-btn{width:40px;height:40px;border-radius:12px;border:1px solid var(--line);background:var(--surface);
  color:var(--ink-2);display:grid;place-items:center}
.icon-btn:hover{color:var(--ink);border-color:var(--ink-3)}
.icon-btn__moon{display:none}
[data-theme="dark"] .icon-btn__sun{display:none}
[data-theme="dark"] .icon-btn__moon{display:block}
.omni{flex:1;max-width:520px;display:flex;align-items:center;gap:10px;height:40px;padding:0 12px;
  border-radius:12px;border:1px solid var(--line);background:var(--surface);color:var(--ink-3);text-align:left}
.omni:hover{border-color:var(--brand);color:var(--ink-2)}
.omni__text{flex:1;font-size:14px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.omni__kbd,.omnibox kbd{font:600 11px var(--ui);padding:2px 6px;border-radius:6px;border:1px solid var(--line);
  background:var(--surface-2);color:var(--ink-3)}
.quick{margin-left:auto}
.quick__list{display:flex;gap:6px;list-style:none;margin:0;padding:0}
.quick__list a{padding:8px 12px;border-radius:10px;font-size:13.5px;font-weight:600;color:var(--ink-2)}
.quick__list a:hover{background:var(--surface-2);color:var(--ink)}

/* ============ Hero ============ */
.hero{position:relative;overflow:hidden;border-radius:28px;padding:38px;margin-bottom:22px;
  background:linear-gradient(135deg,#2a1f8f,#4a37f2 45%,#8b5cf6);color:#fff;
  display:grid;grid-template-columns:1.4fr .8fr;gap:28px;align-items:center;box-shadow:var(--shadow-2)}
.hero::after{content:"";position:absolute;right:-80px;top:-80px;width:320px;height:320px;border-radius:50%;
  background:radial-gradient(circle,rgba(255,255,255,.22),transparent 70%)}
.hero__eyebrow{margin:0 0 8px;font-size:12px;letter-spacing:.14em;text-transform:uppercase;opacity:.8;font-weight:700}
.hero__title{margin:0 0 10px;font-size:clamp(26px,3.4vw,42px);line-height:1.12;letter-spacing:-1px;font-weight:800}
.hero__text{margin:0 0 20px;max-width:52ch;opacity:.9}
.hero__actions{display:flex;gap:10px;flex-wrap:wrap}
.hero__stats{position:relative;display:grid;gap:10px}
.stat{background:rgba(255,255,255,.14);border:1px solid rgba(255,255,255,.18);border-radius:16px;padding:12px 16px}
.stat strong{display:block;font-size:22px;font-weight:800;letter-spacing:-.5px}
.stat span{font-size:12px;opacity:.85}

.btn{display:inline-flex;align-items:center;gap:8px;padding:12px 20px;border-radius:12px;border:0;
  font-weight:700;font-size:14.5px;transition:transform .12s,opacity .15s}
.btn:active{transform:translateY(1px)}
.btn--primary{background:#fff;color:#2a1f8f}
.btn--ghost{background:rgba(255,255,255,.16);color:#fff;border:1px solid rgba(255,255,255,.3)}
.empty .btn--primary{background:var(--brand);color:#fff}

/* ============ Konu rozetleri ============ */
.chips{display:flex;gap:8px;flex-wrap:wrap;margin:0 0 30px}
.chip{display:inline-flex;align-items:center;gap:7px;padding:8px 14px;border-radius:999px;font-size:13.5px;font-weight:650;
  background:var(--surface);border:1px solid var(--line);color:var(--ink-2)}
.chip span{color:hsl(var(--hue) 70% 55%)}
.chip:hover{border-color:hsl(var(--hue) 70% 60%);color:var(--ink);transform:translateY(-1px)}

/* ============ Bolum basliklari ============ */
.section__head{display:flex;align-items:baseline;justify-content:space-between;gap:12px;margin:8px 0 16px}
.section__title{margin:0;font-size:20px;font-weight:800;letter-spacing:-.4px}
.section__meta{font-size:12.5px;color:var(--ink-3);font-weight:600}

/* ============ Kart izgarasi ============ */
.grid{display:grid;gap:18px}
.grid--3{grid-template-columns:repeat(auto-fill,minmax(285px,1fr))}
.card{position:relative;background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);
  overflow:hidden;display:flex;flex-direction:column;transition:transform .18s,box-shadow .18s,border-color .18s}
.card:hover{transform:translateY(-3px);box-shadow:var(--shadow-2);border-color:hsl(var(--hue) 60% 65%)}
.card__link{position:absolute;inset:0;z-index:2}
.card__thumb{position:relative;aspect-ratio:16/9;background:
  linear-gradient(140deg,hsl(var(--hue) 80% 94%),hsl(calc(var(--hue) + 40) 80% 90%));display:grid;place-items:center}
[data-theme="dark"] .card__thumb{background:linear-gradient(140deg,hsl(var(--hue) 40% 18%),hsl(calc(var(--hue) + 40) 40% 14%))}
.card__thumb img{width:100%;height:100%;object-fit:cover}
.card__glyph{font-size:34px;color:hsl(var(--hue) 65% 45%);opacity:.7}
.card__level{position:absolute;top:10px;left:10px;background:rgba(10,12,30,.75);color:#fff;
  font-size:11px;font-weight:800;letter-spacing:.06em;padding:4px 8px;border-radius:8px}
.card__body{padding:16px 18px 18px;display:flex;flex-direction:column;gap:8px;flex:1}
.card__kind{font-size:11px;font-weight:800;letter-spacing:.1em;text-transform:uppercase;color:hsl(var(--hue) 60% 50%)}
.card__title{margin:0;font-size:17px;line-height:1.32;font-weight:750;letter-spacing:-.3px}
.card__text{margin:0;font-size:13.8px;color:var(--ink-2);flex:1}
.card__foot{display:flex;justify-content:space-between;align-items:center;font-size:12.5px;color:var(--ink-3);
  border-top:1px solid var(--line);padding-top:12px;margin-top:4px;font-weight:600}
.card:hover .card__go{color:var(--brand);transform:translateX(3px)}
.card__go{transition:transform .18s,color .18s}

/* ============ Sayfa basligi ============ */
.pagehead{margin:6px 0 26px}
.pagehead__title{margin:6px 0 6px;font-size:clamp(24px,3vw,34px);font-weight:800;letter-spacing:-.8px}
.pagehead__text{color:var(--ink-2);max-width:70ch;margin:0 0 14px}
.crumbs{display:flex;flex-wrap:wrap;gap:7px;font-size:12.5px;color:var(--ink-3);font-weight:600}
.crumbs a:hover{color:var(--brand)}

/* ============ Ders (tekil icerik) ============ */
.lesson{--hue:250}
.lesson__head{max-width:820px;margin:0 auto 26px}
.lesson__title{margin:10px 0 14px;font-size:clamp(28px,4vw,44px);line-height:1.14;letter-spacing:-1.2px;font-weight:800}
.lesson__meta{display:flex;flex-wrap:wrap;gap:8px}
.pill{display:inline-flex;align-items:center;padding:6px 12px;border-radius:999px;font-size:12.5px;font-weight:700;
  background:var(--brand-soft);color:var(--brand)}
.pill--plain{background:var(--surface-2);color:var(--ink-2)}
.pill--level{background:var(--ink);color:var(--bg)}
.lesson__cover{margin:24px 0 0;border-radius:var(--radius);overflow:hidden}
.lesson__wrap{display:grid;grid-template-columns:minmax(0,1fr) 260px;gap:40px;align-items:start;
  max-width:1120px;margin:0 auto}

/* Icerik tipografisi */
.doc{max-width:760px;font-family:var(--serif);font-size:18px;line-height:1.78;color:var(--ink)}
.doc>*:first-child{margin-top:0}
.doc p{margin:0 0 1.15em}
.doc h2,.doc h3,.doc h4{font-family:var(--ui);letter-spacing:-.5px;line-height:1.25;scroll-margin-top:100px}
.doc h2{font-size:26px;font-weight:800;margin:2em 0 .6em;padding-top:.3em;border-top:1px solid var(--line)}
.doc h3{font-size:20px;font-weight:750;margin:1.6em 0 .5em}
.doc h4{font-size:17px;font-weight:700;margin:1.4em 0 .4em}
.doc a{color:var(--brand);text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1.5px}
.doc strong{font-weight:650}
.doc ul,.doc ol{margin:0 0 1.2em;padding-left:1.3em}
.doc li{margin-bottom:.5em}
.doc li::marker{color:var(--brand)}
.doc blockquote{margin:1.6em 0;padding:16px 22px;border-left:3px solid var(--brand);
  background:var(--surface);border-radius:0 var(--radius-sm) var(--radius-sm) 0;font-style:italic;color:var(--ink-2)}
.doc img,.doc figure{border-radius:var(--radius-sm);margin:1.6em 0}
.doc figcaption{font-family:var(--ui);font-size:13px;color:var(--ink-3);text-align:center;margin-top:8px}
.doc code{font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-size:.86em;background:var(--surface-2);
  padding:2px 6px;border-radius:6px}
.doc hr{border:0;border-top:1px solid var(--line);margin:2.2em 0}

/* Tablolar (sitedeki ornek cumle tablolari icin) */
.doc table{width:100%;border-collapse:separate;border-spacing:0;font-family:var(--ui);font-size:15px;
  margin:1.7em 0;background:var(--surface);border:1px solid var(--line);border-radius:var(--radius-sm);overflow:hidden;display:block;overflow-x:auto}
.doc thead th{background:var(--surface-2);font-weight:750;text-align:left;font-size:13px;
  letter-spacing:.03em;text-transform:uppercase;color:var(--ink-2)}
.doc th,.doc td{padding:12px 16px;border-bottom:1px solid var(--line);vertical-align:top}
.doc tbody tr:last-child td{border-bottom:0}
.doc tbody tr:hover{background:var(--surface-2)}

/* Quiz: "Cevabi Gor" acilir kapanir bloklari */
.doc details{margin:.8em 0 1.4em;background:var(--surface);border:1px solid var(--line);
  border-radius:var(--radius-sm);padding:0;overflow:hidden}
.doc details summary{cursor:pointer;list-style:none;font-family:var(--ui);font-weight:700;font-size:14.5px;
  padding:12px 16px;color:var(--brand);display:flex;align-items:center;gap:8px;background:var(--brand-soft)}
.doc details summary::-webkit-details-marker{display:none}
.doc details summary::before{content:"▸";transition:transform .18s}
.doc details[open] summary::before{transform:rotate(90deg)}
.doc details>*:not(summary){padding:0 16px}
.doc details>*:not(summary):first-of-type{padding-top:14px}
.doc details>*:last-child{padding-bottom:14px}

/* Etiketler, paylasim */
.tags{display:flex;flex-wrap:wrap;gap:8px;margin:34px 0 0;font-family:var(--ui)}
.tags a{font-size:12.5px;font-weight:650;padding:6px 12px;border-radius:999px;background:var(--surface-2);color:var(--ink-2)}
.tags a:hover{background:var(--brand);color:#fff}
.share{display:flex;align-items:center;gap:10px;flex-wrap:wrap;margin-top:22px;padding-top:18px;
  border-top:1px solid var(--line);font-family:var(--ui);font-size:13.5px}
.share span{color:var(--ink-3);font-weight:700}
.share a,.share__copy{padding:7px 14px;border-radius:10px;border:1px solid var(--line);background:var(--surface);
  color:var(--ink-2);font-weight:650}
.share a:hover,.share__copy:hover{border-color:var(--brand);color:var(--brand)}

/* Icindekiler */
.toc{position:sticky;top:86px;font-family:var(--ui)}
.toc__inner{border-left:2px solid var(--line);padding-left:16px;max-height:calc(100vh - 140px);overflow-y:auto}
.toc__title{margin:0 0 10px;font-size:11px;letter-spacing:.12em;text-transform:uppercase;color:var(--ink-3);font-weight:800}
.toc__list{list-style:none;margin:0;padding:0;counter-reset:toc}
.toc__item a{display:block;padding:6px 0;font-size:13.5px;color:var(--ink-3);line-height:1.4;font-weight:600}
.toc__item a:hover{color:var(--ink)}
.toc__item--l3 a{padding-left:12px;font-size:12.8px}
.toc__item a.is-current{color:var(--brand)}

/* Ders gecisi */
.steps{display:grid;grid-template-columns:1fr 1fr;gap:14px;max-width:1120px;margin:46px auto 0}
.steps__item{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);padding:16px 20px}
.steps__item span{display:block;font-size:11.5px;letter-spacing:.1em;text-transform:uppercase;color:var(--ink-3);font-weight:800;margin-bottom:4px}
.steps__item strong{font-size:15px;font-weight:700;line-height:1.35}
.steps__item:hover{border-color:var(--brand)}
.steps__item--next{text-align:right;grid-column:2}
.related{max-width:1120px;margin:52px auto 0}
.related .section__title{margin-bottom:16px}

/* Sayfalama */
.pager{display:flex;flex-wrap:wrap;gap:6px;justify-content:center;margin:38px 0 0}
.pager__link,.pager a{min-width:40px;height:40px;padding:0 12px;display:inline-flex;align-items:center;justify-content:center;
  border-radius:11px;border:1px solid var(--line);background:var(--surface);font-size:14px;font-weight:700;color:var(--ink-2)}
.pager a:hover{border-color:var(--brand);color:var(--brand)}
.pager .is-current{background:var(--brand);border-color:var(--brand);color:#fff}

/* Bos durumlar */
.empty{text-align:center;padding:60px 20px;max-width:640px;margin:0 auto}
.empty--big{max-width:900px}
.empty__code{font-size:64px;font-weight:800;letter-spacing:-3px;color:var(--brand);margin:0}
.empty h1,.empty h2{margin:.2em 0 .3em;letter-spacing:-.6px}
.empty p{color:var(--ink-2)}
.empty .grid{margin-top:36px;text-align:left}
.findbar{display:flex;gap:8px;max-width:460px;margin:18px auto}
.findbar input{flex:1;height:46px;padding:0 16px;border-radius:12px;border:1px solid var(--line);
  background:var(--surface);color:var(--ink);font:inherit}
.findbar input:focus{outline:2px solid var(--brand);outline-offset:1px}
.findbar button{height:46px;padding:0 20px;border:0;border-radius:12px;background:var(--brand);color:#fff;font-weight:700}

/* ============ Arama paleti ============ */
.omnibox{position:fixed;inset:0;z-index:120;display:grid;place-items:start center;padding-top:12vh}
.omnibox[hidden]{display:none}
.omnibox__veil{position:absolute;inset:0;background:rgba(8,10,24,.55);backdrop-filter:blur(3px)}
.omnibox__panel{position:relative;z-index:2;width:min(640px,92vw);background:var(--surface);
  border:1px solid var(--line);border-radius:18px;box-shadow:0 30px 70px -20px rgba(0,0,0,.5);overflow:hidden}
.omnibox__form{display:flex;align-items:center;gap:12px;padding:14px 18px;border-bottom:1px solid var(--line);color:var(--ink-3)}
.omnibox__form input{flex:1;border:0;background:none;font:600 16px var(--ui);color:var(--ink);outline:none}
.omnibox__results{max-height:56vh;overflow-y:auto;padding:8px}
.omnires{display:block;padding:11px 14px;border-radius:12px}
.omnires:hover,.omnires.is-active{background:var(--surface-2)}
.omnires strong{display:block;font-size:14.5px;font-weight:700;margin-bottom:2px}
.omnires em{font-style:normal;font-size:12px;color:var(--brand);font-weight:700}
.omnires p{margin:2px 0 0;font-size:12.8px;color:var(--ink-3)}
.omnihint{padding:18px;text-align:center;color:var(--ink-3);font-size:13.5px}

/* ============ Alt bilgi ============ */
.foot{border-top:1px solid var(--line);background:var(--surface);padding:34px 28px 26px}
.foot__grid{display:flex;flex-wrap:wrap;gap:24px;justify-content:space-between;max-width:var(--wrap);margin:0 auto}
.foot__brand{display:flex;align-items:center;gap:12px;max-width:340px}
.foot__brand p{margin:0;font-size:13.5px;color:var(--ink-3)}
.foot__list{display:flex;flex-wrap:wrap;gap:16px;list-style:none;margin:0;padding:0;font-size:13.8px;font-weight:600;color:var(--ink-2)}
.foot__list a:hover{color:var(--brand)}
.foot__legal{max-width:var(--wrap);margin:22px auto 0;font-size:12.5px;color:var(--ink-3);text-align:center}

/* ============ Mobil sekme cubugu ============ */
.tabbar{display:none;position:fixed;left:0;right:0;bottom:0;z-index:70;background:var(--surface);
  border-top:1px solid var(--line);padding:6px 8px calc(6px + env(safe-area-inset-bottom))}
.tabbar__list{display:flex;list-style:none;margin:0;padding:0}
.tabbar__list li{flex:1}
.tabbar__list a,.tabbar__list button{width:100%;display:flex;flex-direction:column;align-items:center;gap:2px;
  background:none;border:0;padding:6px 0;font-size:10.5px;font-weight:700;color:var(--ink-3)}
.tabbar__list span{font-size:17px}

/* ============ Duyarli davranis ============ */
@media (max-width:1180px){
  .lesson__wrap{grid-template-columns:1fr;max-width:820px}
  .toc{position:static;order:-1;border:1px solid var(--line);border-radius:var(--radius);padding:14px 16px}
  .toc__inner{border:0;padding:0;max-height:none}
  .toc__list{columns:2;column-gap:22px}
}
@media (max-width:980px){
  .hero{grid-template-columns:1fr;padding:28px}
  .hero__stats{grid-template-columns:repeat(3,1fr);display:grid}
}
@media (max-width:860px){
  .rail{position:fixed;left:0;top:0;transform:translateX(-100%);transition:transform .22s ease;box-shadow:var(--shadow-2)}
  body.rail-open .rail{transform:none}
  body.rail-open::after{content:"";position:fixed;inset:0;background:rgba(8,10,24,.5);z-index:55}
  .rail__close{display:block}
  .topbar__menu{display:flex}
  .quick{display:none}
  .main{padding:20px 16px 116px}
  .topbar{padding:10px 16px}
  .omni__kbd{display:none}
  .tabbar{display:block}
  .tabbar__list a,.tabbar__list button{min-height:48px;font-size:11px;line-height:1.2;padding:7px 3px}
  .steps{grid-template-columns:1fr}
  .steps__item--next{grid-column:1;text-align:left}
  .doc{font-size:17px}
  .toc__list{columns:1}
}
@media (max-width:520px){
  .hero{padding:24px 20px}
  .hero__actions{display:grid;grid-template-columns:1fr}
  .hero__actions .btn{justify-content:center}
  .hero__stats{grid-template-columns:1fr}
  .omni__text{font-size:13px}
}
@media (prefers-reduced-motion:reduce){
  *{animation-duration:.01ms!important;transition-duration:.01ms!important;scroll-behavior:auto!important}
}
@media print{
  .rail,.topbar,.tabbar,.toc,.share,.steps,.related,.foot,.progress{display:none!important}
  .doc{max-width:none;font-size:12pt}
}