/* Konu ve ders sayfalarının stili. Ana sayfanın CSS'i landing.html'e gömülü;
   içerik sayfaları ayrı ve hafif bir sayfa (bir kez inip önbellekte kalıyor).
   Marka aynı: Sora + Plus Jakarta, mor, açık/koyu tema. */
@font-face{font-family:'Sora';font-weight:100 800;font-display:swap;src:url(/f/sora.woff2) format('woff2')}
@font-face{font-family:'Plus Jakarta Sans';font-weight:200 800;font-display:swap;src:url(/f/jakarta.woff2) format('woff2')}

:root{
  --ground:#F6F5FB; --surface:#fff; --ink:#15121F; --soft:#5C5872; --faint:#8B87A0;
  --accent:#5B4BE8; --accent-deep:#3A2EA8; --tint:#EEEBFF; --line:#E7E4F2;
  --ok:#15A05B; --ok-bg:#E6F7EE;
  --disp:'Sora',system-ui,sans-serif; --body:'Plus Jakarta Sans',system-ui,sans-serif;
  --shadow:0 2px 4px rgba(58,46,168,.04),0 10px 24px rgba(58,46,168,.08);
}
:root[data-theme="dark"]{
  --ground:#0C0918; --surface:#17132C; --ink:#F1EFFA; --soft:#ABA4C8; --faint:#7B7599;
  --accent:#6A55E8; --accent-deep:#A492FF; --tint:#221C44; --line:#2B2450;
  --ok:#3DD68C; --ok-bg:#12331F;
  --shadow:0 2px 4px rgba(0,0,0,.3),0 10px 24px rgba(0,0,0,.4);
}
*{box-sizing:border-box}
body{margin:0;background:var(--ground);color:var(--ink);font-family:var(--body);
  line-height:1.62;-webkit-font-smoothing:antialiased}
a{color:inherit}
main,header,footer{width:min(100% - 40px,760px);margin-inline:auto}

header{display:flex;align-items:center;justify-content:space-between;gap:16px;
  padding:20px 0;margin-bottom:8px}
.brand{display:flex;align-items:center;gap:10px;font-family:var(--disp);
  font-weight:800;font-size:1.15rem;letter-spacing:-.02em;text-decoration:none}
.brand .lg{width:34px;height:34px;border-radius:10px;display:grid;place-items:center;
  background:linear-gradient(150deg,var(--accent),var(--accent-deep));
  box-shadow:0 6px 14px rgba(91,75,232,.3)}
.brand .lg svg{width:62%;height:62%;display:block}
.cta{font-family:var(--disp);font-weight:700;font-size:.9rem;text-decoration:none;
  background:var(--accent);color:#fff;padding:10px 17px;border-radius:999px;
  transition:transform .35s cubic-bezier(.32,.72,0,1)}
.cta:hover{transform:translateY(-2px)} .cta:active{transform:scale(.97)}

.bc{font-size:.82rem;color:var(--faint);margin:8px 0 18px}
.bc a{color:var(--faint);text-decoration:none} .bc a:hover{color:var(--accent-deep)}

h1{font-family:var(--disp);font-weight:800;letter-spacing:-.035em;line-height:1.1;
  font-size:clamp(1.85rem,6.4vw,2.5rem);margin:0 0 12px;text-wrap:balance}
h2{font-family:var(--disp);font-weight:800;letter-spacing:-.028em;
  font-size:clamp(1.3rem,4.4vw,1.6rem);margin:44px 0 16px}
h3{font-family:var(--disp);font-weight:700;letter-spacing:-.02em;font-size:1.05rem;margin:0 0 10px}
h4{font-family:var(--disp);font-weight:700;font-size:.92rem;margin:0 0 8px;color:var(--soft)}
.lead{font-size:1.06rem;color:var(--soft);margin:0 0 22px;max-width:62ch}

.facts{display:flex;flex-wrap:wrap;gap:8px;list-style:none;padding:0;margin:0 0 8px}
.facts li{font-size:.85rem;color:var(--soft);background:var(--tint);
  border:1px solid var(--line);border-radius:999px;padding:6px 13px}
.facts b{color:var(--ink);font-family:var(--disp);font-weight:700}

.blk{background:var(--surface);border:1px solid var(--line);border-radius:18px;
  padding:20px 20px 12px;margin-bottom:14px;box-shadow:var(--shadow)}
.pill{display:inline-block;font-family:var(--disp);font-weight:800;font-size:.62rem;
  letter-spacing:.16em;color:var(--accent-deep);background:var(--tint);
  border:1px solid var(--line);border-radius:999px;padding:5px 11px;margin-bottom:10px}
.blk dl{margin:0}
.blk dl>div{padding:11px 0;border-top:1px solid var(--line)}
.blk dl>div:first-child{border-top:0;padding-top:2px}
.blk dt{font-family:var(--disp);font-weight:700;font-size:.95rem}
.blk dd{margin:3px 0 0;color:var(--soft);font-size:.94rem}

.note{font-size:.84rem;color:var(--faint);margin:12px 0 4px;line-height:1.55}
.blk dl>div:first-child{border-top:0;padding-top:2px}
.ex{background:var(--surface);border:1px solid var(--line);border-radius:18px;
  padding:20px;margin-bottom:16px;box-shadow:var(--shadow)}
.stem{font-weight:600;margin:0 0 14px}
.opts{list-style:none;padding:0;margin:0 0 16px;display:grid;gap:8px;counter-reset:o}
.opts li{border:1.5px solid var(--line);border-radius:12px;padding:10px 13px;font-size:.95rem}
.opts li b{font-family:var(--disp);color:var(--accent-deep);margin-right:8px}
.opts li.ok{border-color:var(--ok);background:var(--ok-bg)}
.opts li.ok b{color:var(--ok)}
.sol{border-top:1px solid var(--line);padding-top:14px}
.sol ol{margin:0 0 10px;padding-left:20px;color:var(--soft);font-size:.95rem}
.sol li{margin-bottom:5px}
.ans{margin:0;font-size:.95rem;color:var(--ok)}
.ans b{font-family:var(--disp)}

.topics{list-style:none;padding:0;margin:0;display:grid;gap:10px}
.topics a{display:flex;justify-content:space-between;align-items:center;gap:14px;
  background:var(--surface);border:1px solid var(--line);border-radius:14px;
  padding:15px 17px;text-decoration:none;box-shadow:var(--shadow);
  transition:transform .35s cubic-bezier(.32,.72,0,1)}
.topics a:hover{transform:translateX(3px)}
.tn{font-family:var(--disp);font-weight:700}
.tm{font-size:.82rem;color:var(--faint);white-space:nowrap}

.cta-box{background:linear-gradient(150deg,var(--accent),var(--accent-deep));
  color:#fff;border-radius:22px;padding:26px 24px;margin:44px 0 10px;text-align:center}
.cta-box h2{margin:0 0 8px;color:#fff}
.cta-box p{margin:0 0 18px;color:rgba(255,255,255,.85);font-size:.96rem}
.btn{display:inline-block;background:#fff;color:var(--accent-deep);font-family:var(--disp);
  font-weight:800;text-decoration:none;padding:13px 24px;border-radius:999px;
  transition:transform .35s cubic-bezier(.32,.72,0,1)}
.btn:hover{transform:translateY(-2px)} .btn:active{transform:scale(.97)}
.cta-box .alt{display:block;margin-top:14px;color:rgba(255,255,255,.85);font-size:.9rem}

footer{margin-top:56px;padding:26px 0 40px;border-top:1px solid var(--line);
  color:var(--faint);font-size:.86rem}
footer nav{display:flex;flex-wrap:wrap;gap:16px;margin-bottom:12px}
footer a{color:var(--soft);text-decoration:none}
footer a:hover{color:var(--ink)}
footer p{margin:0}

:focus-visible{outline:3px solid var(--accent);outline-offset:3px;border-radius:6px}
@media(prefers-reduced-motion:reduce){*{transition:none!important}}

/* Google "tercih edilen kaynak" rozeti. Açık temada KOYU rozet, koyu temada
   AÇIK rozet — Google'ın kendi varyant mantığı. background-image olarak
   veriliyor ki iki dosya birden inmesin (img ile ikisi de inerdi). */
.gps{display:block;width:min(180px,100%);aspect-ratio:338/106;margin:22px 0 0;
  background:url(/b/gps-d.webp) center/contain no-repeat}
:root[data-theme="dark"] .gps{background-image:url(/b/gps-l.webp)}