/* ===== mathe-kurs.de Premium Onepager ===== */
:root{
  --navy:#122066;
  --navy2:#0e184d;
  --gold:#c9a227;
  --gold2:#e0c45a;
  --ink:#0b1020;
  --muted:#5c647e;
  --bg:#f4f6ff;
  --card: rgba(255,255,255,.74);
  --card2: rgba(255,255,255,.86);
  --stroke: rgba(18,32,102,.14);
  --shadow: 0 18px 48px rgba(7,14,34,.18);
  --shadow2: 0 12px 30px rgba(7,14,34,.12);
  --r: 18px;
  --max: 1120px;
}

*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;
  font-family: ui-serif, Georgia, "Times New Roman", Times, serif;
  color:var(--ink);
  background:#fff;
}
h1,h2,h3{margin:0}
a{color:inherit}

.container{width:min(var(--max), calc(100% - 40px)); margin-inline:auto;}

.sr-only{position:absolute; left:-9999px}

/* Header */
.header{
  position:sticky; top:0; z-index:1000;
  background:rgba(255,255,255,.78);
  backdrop-filter: blur(10px);
  border-bottom:1px solid rgba(18,32,102,.10);
}
.header__inner{display:flex; align-items:center; justify-content:space-between; gap:16px; padding:10px 0;}
.brand__logo{height:64px; width:auto; display:block;}

.nav{display:flex; align-items:center; gap:10px;}
.nav__links{display:flex; align-items:center; gap:18px;}
.nav__links a{
  text-decoration:none;
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Arial;
  font-weight:650;
  font-size:14px;
  color:var(--navy2);
  padding:10px 12px;
  border-radius:12px;
}
.nav__links a:hover{background:rgba(18,32,102,.06)}
.nav__toggle{display:none; border:0; background:transparent; padding:10px; border-radius:12px;}
.burger{width:24px;height:2px;background:var(--navy2); position:relative; display:block;}
.burger:before,.burger:after{content:""; position:absolute; left:0; width:24px;height:2px;background:var(--navy2);}
.burger:before{top:-7px} .burger:after{top:7px}

/* Buttons */
.btn{
  display:inline-flex; align-items:center; justify-content:center;
  text-decoration:none;
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Arial;
  font-weight:800;
  border-radius:14px;
  padding:12px 18px;
  border:1px solid transparent;
  cursor:pointer;
}
.btn--sm{padding:10px 14px; border-radius:12px; font-size:14px}
.btn--gold{
  background:linear-gradient(180deg, var(--gold2), var(--gold));
  color:#101424;
  box-shadow:0 10px 26px rgba(201,162,39,.22);
}
.btn--gold:hover{filter:brightness(.98)}

/* Hero */
.hero{
  position:relative;
  min-height: 420px;
  display:grid;
  place-items:center;
  text-align:left;
  overflow:hidden;
}
.hero__bg{
  position:absolute; inset:0;
  background:
    linear-gradient(90deg, rgba(255,255,255,.92) 0%, rgba(255,255,255,.70) 45%, rgba(255,255,255,.20) 80%),
    url('assets/hero.jpg') center/cover no-repeat;
  filter:saturate(1.02);
}
.hero__content{
  position:relative;
  padding:64px 0;
}
.hero h1{
  font-size: clamp(34px, 4vw, 56px);
  line-height:1.08;
  letter-spacing:-.5px;
  color:var(--navy2);
}
.hero .accent{color:var(--gold)}
.lead{
  margin:16px 0 18px;
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Arial;
  font-size:16px;
  color:rgba(14,24,77,.72);
}

/* Sections */
.section{position:relative; padding:74px 0;}
.section--soft{background:linear-gradient(180deg, #fff, var(--bg))}
.section--lake{background:#fff}
.section__bg{
  position:absolute; inset:0;
  background:
    radial-gradient(900px 600px at 50% 0%, rgba(255,255,255,.95), rgba(255,255,255,.62) 55%, rgba(255,255,255,.30) 85%),
    url('assets/lake.jpg') center/cover no-repeat;
  opacity:.95;
  filter:saturate(1.02);
}
.section--lake .container{position:relative}

.h2{
  text-align:center;
  font-size: clamp(28px, 3vw, 44px);
  color:var(--navy2);
  margin-bottom:28px;
  letter-spacing:-.4px;
}
.h3{
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Arial;
  letter-spacing:-.2px;
}

.center{text-align:center; margin-top:18px}

/* Triads */
.triads{
  display:grid;
  grid-template-columns: repeat(3, 1fr);
  gap:26px;
  align-items:start;
  text-align:center;
  margin: 18px 0 18px;
}
.triad{
  padding:18px 16px;
}
.triad__icon{
  width:54px; height:54px;
  margin:0 auto 10px;
  border-radius:16px;
  display:grid; place-items:center;
  color:var(--gold);
  background:rgba(255,255,255,.70);
  border:1px solid rgba(201,162,39,.35);
  box-shadow: var(--shadow2);
  font-family: ui-sans-serif, system-ui;
  font-weight:900;
}
.triad h3{
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Arial;
  color:var(--navy2);
  font-size:18px;
  margin:6px 0 8px;
}
.triad p{
  margin:0;
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Arial;
  color:rgba(14,24,77,.72);
  font-size:14px;
  line-height:1.5;
}

/* Cards */
.cards{
  display:grid;
  grid-template-columns: repeat(2, 1fr);
  gap:24px;
  margin-top:8px;
}
.card{
  background:var(--card);
  border:1px solid var(--stroke);
  border-radius: var(--r);
  box-shadow: var(--shadow2);
  padding:22px 22px 18px;
}
.card h3{
  color:var(--navy2);
  font-size:22px;
  margin-bottom:8px;
}
.card .date{
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Arial;
  color:rgba(14,24,77,.70);
  margin:0 0 12px;
}
.card ul{
  margin:0 0 14px;
  padding-left:18px;
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Arial;
  color:rgba(14,24,77,.76);
}
.card li{margin:8px 0}

/* Split panel */
.split{
  display:grid;
  grid-template-columns: 1.05fr .95fr;
  gap:26px;
  align-items:center;
}
.panel{
  background:var(--card2);
  border:1px solid var(--stroke);
  border-radius: var(--r);
  box-shadow: var(--shadow2);
  padding:22px;
}
.panel h3{color:var(--navy2); font-size:22px; margin-bottom:8px}
.panel .muted{margin:0 0 12px}
.panel ul{
  margin:0 0 14px;
  padding-left:18px;
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Arial;
  color:rgba(14,24,77,.76);
}
.media img{
  width:100%;
  height:auto;
  border-radius: var(--r);
  box-shadow: var(--shadow);
  border:1px solid rgba(255,255,255,.55);
}

/* About */
.about{
  display:grid;
  grid-template-columns: 1.05fr .95fr;
  gap:26px;
  align-items:center;
}
.about__text p{
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Arial;
  color:rgba(14,24,77,.78);
  line-height:1.65;
}
.about__text ul{
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Arial;
  color:rgba(14,24,77,.76);
}
.about__media img{
  width:100%;
  border-radius: var(--r);
  box-shadow: var(--shadow);
  border:1px solid rgba(18,32,102,.10);
}

/* FAQ + Form */
.faqgrid{
  display:grid;
  grid-template-columns: 1.05fr .95fr;
  gap:24px;
  align-items:start;
}
.faq details{
  background:var(--card2);
  border:1px solid var(--stroke);
  border-radius: var(--r);
  box-shadow: var(--shadow2);
  padding:14px 16px;
  margin:10px 0;
}
.faq summary{
  cursor:pointer;
  font-family: ui-sans-serif, system-ui;
  font-weight:900;
  color:var(--navy2);
}
.faq p{
  margin:10px 0 0;
  font-family: ui-sans-serif, system-ui;
  color:rgba(14,24,77,.76);
  line-height:1.55;
}

.formwrap{
  background:var(--card2);
  border:1px solid var(--stroke);
  border-radius: var(--r);
  box-shadow: var(--shadow2);
  padding:18px;
}
.muted{
  font-family: ui-sans-serif, system-ui;
  color:rgba(14,24,77,.70);
}
.form label{
  display:grid;
  gap:6px;
  margin:12px 0;
  font-family: ui-sans-serif, system-ui;
  font-weight:800;
  color:var(--navy2);
}
.form input, .form textarea{
  border-radius:14px;
  border:1px solid rgba(18,32,102,.18);
  background:rgba(255,255,255,.92);
  padding:12px 12px;
  font-family: ui-sans-serif, system-ui;
  outline:none;
}
.form input:focus, .form textarea:focus{
  border-color: rgba(201,162,39,.55);
  box-shadow: 0 0 0 4px rgba(201,162,39,.18);
}
.tiny{font-size:12px}
.contactline{
  margin-top:12px;
  font-family: ui-sans-serif, system-ui;
  color:rgba(14,24,77,.72);
}
.contactline a{color:var(--navy2); text-decoration:none}
.contactline a:hover{color:var(--gold)}

/* Footer */
.footer{
  background: var(--navy2);
  color: rgba(255,255,255,.86);
  padding:22px 0;
}
.footer__inner{
  display:flex;
  justify-content:space-between;
  gap:14px;
  align-items:center;
  flex-wrap:wrap;
  font-family: ui-sans-serif, system-ui;
}
.footer__links{display:flex; gap:14px}
.footer a{color:rgba(255,255,255,.86); text-decoration:none}
.footer a:hover{color:var(--gold2)}

/* Responsive */
@media (max-width: 980px){
  .triads{grid-template-columns:1fr}
  .cards{grid-template-columns:1fr}
  .split{grid-template-columns:1fr}
  .about{grid-template-columns:1fr}
  .faqgrid{grid-template-columns:1fr}
}
@media (max-width: 760px){
  .brand__logo{height:52px}
  .nav__toggle{display:inline-flex}
  .nav__links{
    position:absolute;
    right:20px; top:72px;
    background:rgba(255,255,255,.96);
    border:1px solid rgba(18,32,102,.10);
    border-radius:18px;
    padding:10px;
    box-shadow: var(--shadow2);
    display:none;
    flex-direction:column;
    gap:8px;
    width:min(92vw, 320px);
  }
  .nav__links.open{display:flex}
  .nav__links a{width:100%}
}