/* RSD – Projektstudien | Longpage v1.1_final | Stand 13.09.2026
   Design-Tokens gemäß Homepage-Handoff v1 (12.09.2026). Reines CSS, keine externen Ressourcen. */

@font-face{font-family:"IBM Plex Sans";font-style:normal;font-weight:400;font-display:swap;src:url("../fonts/IBMPlexSans-Regular.woff2") format("woff2")}
@font-face{font-family:"IBM Plex Sans";font-style:normal;font-weight:500;font-display:swap;src:url("../fonts/IBMPlexSans-Medium.woff2") format("woff2")}
@font-face{font-family:"IBM Plex Sans";font-style:normal;font-weight:600;font-display:swap;src:url("../fonts/IBMPlexSans-SemiBold.woff2") format("woff2")}

:root{--navy:#10233F;--ink:#1F2933;--steel:#4F5B66;--mist:#E9EDF1;--paper:#FFFFFF;--rule:#C9D1DA;--accent:#2B5C8A;--maxw:1120px;--gutter:clamp(20px,4vw,48px)}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}}
body{margin:0;font-family:"IBM Plex Sans","Inter",system-ui,-apple-system,"Segoe UI",Roboto,Arial,sans-serif;font-size:17px;line-height:1.6;color:var(--ink);background:var(--paper);-webkit-font-smoothing:antialiased}
a{color:var(--accent);text-decoration-thickness:1px;text-underline-offset:3px}
a:focus-visible,button:focus-visible{outline:3px solid var(--accent);outline-offset:3px}
.skip{position:absolute;left:-999px;top:8px;background:var(--paper);color:var(--navy);padding:8px 12px;z-index:30}
.skip:focus{left:8px}
.wrap{max-width:var(--maxw);margin:0 auto;padding:0 var(--gutter)}
p{margin:0 0 1em;max-width:70ch}
h1,h2,h3{margin:0;font-weight:600;line-height:1.15;letter-spacing:-0.01em}

/* Navigation */
.nav{border-bottom:1px solid var(--rule);background:var(--paper);position:sticky;top:0;z-index:10}
.nav .wrap{display:flex;align-items:center;justify-content:space-between;gap:24px;min-height:68px}
.brand{display:flex;align-items:center;text-decoration:none}
.brand img{display:block;height:36px;width:auto}
.nav ul{list-style:none;margin:0;padding:0;display:flex}
.nav li+li{margin-left:28px}
.nav li a{color:var(--ink);text-decoration:none;font-size:15px;padding:6px 0;border-bottom:2px solid transparent;white-space:nowrap}
.nav li a[aria-current]{border-bottom-color:var(--navy);font-weight:500}
.nav li a:hover{border-bottom-color:var(--rule)}

/* Hero (typografisch, ohne Bild) */
.hero{background:var(--navy);color:#fff;padding:clamp(56px,9vw,120px) 0 clamp(48px,7vw,96px)}
.hero .wrap{display:grid;grid-template-columns:minmax(0,7fr) minmax(0,4fr);gap:clamp(32px,6vw,96px);align-items:start}
.eyebrow{font-size:15px;color:#B8C4D2;margin-bottom:18px}
.hero h1{font-size:clamp(30px,4.4vw,50px);font-weight:500;max-width:18ch}
.hero .sub{margin-top:28px;font-size:18px;line-height:1.6;color:#D6DEE8;max-width:60ch}
.btn{display:inline-block;margin-top:32px;padding:14px 22px;background:#fff;color:var(--navy);text-decoration:none;font-weight:500;font-size:16px;border:1px solid #fff}
.btn:hover{background:var(--mist)}
.index{border-left:1px solid rgba(255,255,255,.25);padding-left:24px;margin-top:8px}
.index h2{font-size:13px;font-weight:500;color:#B8C4D2;margin-bottom:14px}
.index ol{list-style:none;margin:0;padding:0;counter-reset:s}
.index li{counter-increment:s;border-top:1px solid rgba(255,255,255,.15);padding:12px 0}
.index li:first-child{border-top:0;padding-top:0}
.index a{color:#fff;text-decoration:none;display:grid;grid-template-columns:32px 1fr;gap:10px;font-size:15px;line-height:1.35}
.index a::before{content:"0" counter(s);color:#8FA3BD;font-variant-numeric:tabular-nums}
.index a:hover{text-decoration:underline}

/* Sektionen */
.section{padding:clamp(56px,8vw,104px) 0}
.section h2{font-size:clamp(24px,3vw,32px);margin-bottom:20px;max-width:24ch}
.section .lead{font-size:18px;color:var(--ink)}
.ki-hinweis{margin:24px 0 0;padding:14px 0 0;border-top:1px solid var(--rule);font-size:14px;line-height:1.55;color:var(--steel);max-width:78ch}

/* Projektlogik – Schritte */
.rail{list-style:none;margin:40px 0 0;padding:0;display:grid;grid-template-columns:repeat(5,1fr);gap:0;counter-reset:r;border-top:1px solid var(--navy)}
.rail li{counter-increment:r;padding:18px 20px 0 0;position:relative;font-size:15px;line-height:1.45}
.rail li::before{content:"0" counter(r);display:block;font-size:13px;color:var(--steel);margin-bottom:6px;font-variant-numeric:tabular-nums}
.rail li::after{content:"";position:absolute;top:-1px;left:0;width:10px;height:10px;background:var(--navy);transform:translateY(-50%);border-radius:50%}

/* Studien */
.studie{border-top:1px solid var(--rule);padding:clamp(48px,7vw,88px) 0}
.studie .wrap{display:grid;grid-template-columns:minmax(0,4fr) minmax(0,8fr);gap:clamp(28px,5vw,72px)}
.studie .kopf{position:sticky;top:96px;align-self:start}
.studie .nr{font-size:14px;color:var(--steel);margin-bottom:10px;font-variant-numeric:tabular-nums}
.studie h2{font-size:clamp(22px,2.6vw,28px);margin-bottom:14px}
.studie .kurz{font-size:17px;color:var(--ink)}
.kurzform{margin:28px 0 0;padding:18px 0 0;border-top:1px solid var(--rule);font-size:15px;line-height:1.55;color:var(--steel)}
.kurzform b{display:block;font-weight:500;color:var(--ink);margin-bottom:4px;font-size:14px}
.bilder{display:grid;grid-template-columns:1fr 1fr;gap:18px;margin:0 0 36px}
.bilder figure:first-child{grid-column:1/-1}
.bilder.zwei figure{grid-column:1/-1}
figure{margin:0}
figure img{display:block;width:100%;height:auto;aspect-ratio:4/3;object-fit:cover;object-position:center;background:var(--mist)}
.bilder figure:first-child img,.bilder.zwei img{aspect-ratio:16/9}
figcaption{font-size:14px;line-height:1.5;color:var(--steel);margin-top:8px}
figcaption .ki{display:inline-block;margin-top:2px;font-size:12px;color:var(--steel);letter-spacing:.01em}
figcaption .ki::before{content:"";display:inline-block;width:6px;height:6px;border:1px solid var(--steel);margin-right:7px;vertical-align:1px}
.felder{display:grid;grid-template-columns:1fr 1fr;gap:28px 40px}
.felder h3{font-size:14px;font-weight:500;color:var(--steel);margin-bottom:8px}
.felder p{font-size:16px;margin:0}
.hinweis{margin-top:32px;padding-top:14px;border-top:1px solid var(--rule);font-size:13px;line-height:1.5;color:var(--steel);max-width:none}

/* Einordnung */
.einordnung{background:var(--mist)}
.einordnung ul{list-style:none;margin:24px 0 0;padding:0;max-width:78ch}
.einordnung li{padding:16px 0;border-top:1px solid #D5DCE4;font-size:16px}
.einordnung li:first-child{border-top:0;padding-top:0}

/* CTA */
.cta{background:var(--navy);color:#fff}
.cta h2{color:#fff}
.cta p{color:#D6DEE8;font-size:18px;max-width:62ch}
.cta .wrap{display:grid;grid-template-columns:minmax(0,7fr) minmax(0,5fr);gap:48px;align-items:end}
.kontakt{font-size:15px;line-height:1.6;color:#D6DEE8}
.kontakt b{color:#fff;font-weight:500}
.kontakt a{color:#fff}

/* Footer (auf allen Seiten identisch) */
footer{padding:36px 0 44px;border-top:1px solid var(--rule);font-size:13px;color:var(--steel);line-height:1.55}
footer .wrap{display:grid;grid-template-columns:minmax(0,7fr) minmax(0,5fr);gap:32px}
footer p{max-width:none}
footer ul{list-style:none;margin:0;padding:0;display:flex;flex-wrap:wrap;gap:18px}
footer a{color:var(--steel)}

/* Breakpoints */
@media (max-width:900px){
 .hero .wrap,.studie .wrap,.cta .wrap,footer .wrap{grid-template-columns:1fr}
 .studie .kopf{position:static}
 .rail{grid-template-columns:1fr;border-top:0;border-left:1px solid var(--navy);margin-top:28px}
 .rail li{padding:0 0 18px 20px}
 .rail li::after{top:6px;left:-1px;transform:translateX(-50%)}
 .nav li+li{margin-left:16px}
 .nav li a{font-size:14px}
 .brand img{height:30px}
}
@media (max-width:600px){
 .bilder,.felder{grid-template-columns:1fr}
 .bilder figure img{aspect-ratio:4/3}
 .bilder figure:first-child img,.bilder.zwei img{aspect-ratio:16/9}
 .nav .wrap{flex-wrap:wrap;padding-top:10px;padding-bottom:10px;gap:8px 24px}
 .nav ul{flex-wrap:wrap;gap:2px 16px}
 .nav li+li{margin-left:0}
}
@media print{
 .nav{position:static}
 .studie .kopf{position:static}
}