:root{
  --bg:#08111f;
  --panel:#0f1d30;
  --panel2:#13243b;
  --text:#f5f7fb;
  --muted:#a8b4c5;
  --accent:#3d8bfd;
  --accent2:#62b0ff;
  --good:#29c36a;
  --bad:#ef5350;
  --border:#253a56;
}
*{box-sizing:border-box}
body{
  margin:0;
  font-family:Inter,system-ui,-apple-system,Segoe UI,Roboto,Arial,sans-serif;
  background:linear-gradient(180deg,#06101c 0%,#0a1524 100%);
  color:var(--text);
}
button,input,select,textarea{font:inherit}
.app{max-width:1150px;margin:auto;padding:20px}
.topbar{
  display:flex;gap:16px;justify-content:space-between;align-items:center;
  padding:14px 16px;background:rgba(15,29,48,.94);border:1px solid var(--border);
  border-radius:18px;position:sticky;top:10px;z-index:10;backdrop-filter:blur(10px)
}
.brand{display:flex;align-items:center;gap:12px}
.badge{width:44px;height:44px;border-radius:12px;background:linear-gradient(135deg,#0d4d8f,#49a2ff);display:grid;place-items:center;font-weight:800}
.nav{display:flex;gap:8px;flex-wrap:wrap}
button{
  border:1px solid var(--border);background:#12243b;color:var(--text);
  padding:10px 14px;border-radius:12px;cursor:pointer
}
button:hover{border-color:#4c77aa}
button.primary{background:var(--accent);border-color:var(--accent)}
button.danger{background:#3b1720;border-color:#6f2736}
.hero{padding:38px 8px 20px}
.hero h1{font-size:clamp(28px,5vw,50px);margin:0 0 10px}
.hero p{color:var(--muted);max-width:750px;font-size:18px}
.grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:14px}
.card{
  background:linear-gradient(180deg,var(--panel) 0%,#0c1929 100%);
  border:1px solid var(--border);border-radius:18px;padding:18px
}
.card h3{margin-top:0}
.muted{color:var(--muted)}
.kpi{font-size:30px;font-weight:800}
.subject-card{cursor:pointer;transition:.15s transform,.15s border-color}
.subject-card:hover{transform:translateY(-2px);border-color:#4a79b1}
.pill{display:inline-block;padding:5px 9px;border-radius:999px;background:#17304e;color:#b8d8ff;font-size:12px}
.section{margin:18px 0}
.hidden{display:none!important}
.question{font-size:23px;font-weight:750;margin-bottom:18px}
.answers{display:grid;gap:10px}
.answer{text-align:left;padding:14px;background:#112238}
.answer.correct{border-color:var(--good);background:#11301f}
.answer.wrong{border-color:var(--bad);background:#32181b}
.explanation{margin-top:14px;padding:14px;border-left:4px solid var(--accent2);background:#102036;border-radius:10px}
.progressbar{height:10px;background:#172b45;border-radius:999px;overflow:hidden}
.progressbar>div{height:100%;background:linear-gradient(90deg,var(--accent),var(--accent2))}
.row{display:flex;gap:10px;flex-wrap:wrap;align-items:center}
.field{display:grid;gap:6px;margin-bottom:12px}
input,select,textarea{
  width:100%;background:#0b1828;color:var(--text);border:1px solid var(--border);
  border-radius:10px;padding:10px
}
table{width:100%;border-collapse:collapse}
th,td{padding:10px;border-bottom:1px solid var(--border);text-align:left;vertical-align:top}
.small{font-size:13px}
.footer{padding:30px 4px;color:var(--muted);font-size:13px}
.notice{padding:12px;border:1px solid #705d1e;background:#2d2711;border-radius:12px;color:#f1d66d}
@media(max-width:720px){
  .topbar{position:static;align-items:flex-start;flex-direction:column}
  .nav{width:100%}
  .nav button{flex:1}
  table{font-size:13px}
}

.auth-grid{grid-template-columns:repeat(auto-fit,minmax(280px,1fr));max-width:850px}
.status-good{border-color:#24683f;background:#0e2a1a;color:#9ee5b8}
.status-warn{border-color:#705d1e;background:#2d2711;color:#f1d66d}
.status-bad{border-color:#6f2736;background:#32181b;color:#ffb0b0}
.admin-form-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px}
.admin-heading-row{justify-content:space-between;align-items:center}
.admin-heading-row h3{margin:0}
.file-input{max-width:420px}
.admin-status{margin-top:10px;min-height:20px}
.actions{display:flex;gap:6px;flex-wrap:wrap;min-width:155px}
.source-link{display:inline-block;margin-top:10px;color:#9ecbff}
.meta-line{margin-top:10px;color:var(--muted);font-size:13px}
@media(max-width:720px){.admin-form-grid{grid-template-columns:1fr}.file-input{max-width:none}.actions{min-width:130px}}


/* Version 6: Kapitel- und Themenauswahl */
.subject-card-meta{justify-content:space-between}
.subtle-pill{background:#10263d;color:#93b8df}
.topic-hero-meta{margin:14px 0 4px}
.chapter-grid{align-items:start}
.chapter-card{display:flex;flex-direction:column;min-height:250px}
.chapter-card h3{margin:12px 0 6px}
.chapter-title-row{justify-content:flex-start}
.topic-list{display:flex;flex-wrap:wrap;gap:8px;margin:10px 0 16px}
.topic-chip{padding:8px 10px;border-radius:999px;background:#10263d;border-color:#294969;font-size:13px;text-align:left}
.topic-chip:hover{background:#173552;border-color:#4b79aa}
.chapter-actions{margin-top:auto;padding-top:4px}
.chapter-actions .primary{width:100%}
@media(max-width:720px){.chapter-card{min-height:0}.topic-chip{width:100%;border-radius:12px}.subject-card-meta{justify-content:flex-start}}

/* Version 7: realistischer Prüfungsmodus */
.exam-config-card{max-width:900px}
.exam-config-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:14px}
.exam-info{padding:14px;margin:4px 0 16px;border:1px solid var(--border);background:#0b1828;border-radius:12px;color:#c9d6e6;line-height:1.5}
.exam-start-btn{min-width:220px}
.quiz-heading-row{justify-content:space-between;align-items:center}
.quiz-heading-row h1{margin-bottom:10px}
.timer-pill{background:#2d2711;color:#f1d66d;border:1px solid #705d1e}
.answer.selected{border-color:#6e9fd4;background:#173552;box-shadow:inset 0 0 0 1px #6e9fd4}
.result-pass{background:#0e2a1a;color:#9ee5b8;border:1px solid #24683f}
.result-fail{background:#32181b;color:#ffb0b0;border:1px solid #6f2736}
.exam-kpis{grid-template-columns:repeat(4,minmax(0,1fr))}
.exam-subject-card{display:grid;gap:10px}
.exam-subject-head{justify-content:space-between}
.result-bar{height:9px;background:#172b45;border-radius:999px;overflow:hidden}
.result-bar>div{height:100%;background:linear-gradient(90deg,var(--accent),var(--accent2))}
button:disabled{cursor:default;opacity:.82}
@media(max-width:720px){.exam-config-grid{grid-template-columns:1fr}.exam-kpis{grid-template-columns:repeat(2,minmax(0,1fr))}.quiz-heading-row{align-items:flex-start}.exam-start-btn{width:100%}}


/* Version 8: persönlicher Prüfungsverlauf */
.history-kpis{grid-template-columns:repeat(4,minmax(0,1fr))}
.history-section-head{justify-content:space-between;align-items:flex-start}
.history-section-head h2{margin:0 0 4px}
.trend-list{display:grid;gap:10px;margin-top:16px}
.trend-item{display:grid;grid-template-columns:34px minmax(0,1fr) 54px;gap:10px;align-items:center}
.trend-label{font-size:12px;color:var(--muted);text-align:center}
.trend-bar-track{height:12px;background:#172b45;border-radius:999px;overflow:hidden}
.trend-bar-fill{height:100%;border-radius:999px;background:linear-gradient(90deg,var(--accent),var(--accent2))}
.trend-pass{box-shadow:inset 0 0 0 1px #24683f}
.trend-fail{opacity:.78}
.history-list{display:grid;gap:12px}
.history-card{display:grid;gap:12px}
.history-head{justify-content:space-between;align-items:flex-start}
.history-score{font-size:34px;font-weight:800;line-height:1}
.history-date{margin-top:7px}
.history-meta{color:#c9d6e6;line-height:1.5}
.history-card details{border-top:1px solid var(--border);padding-top:10px}
.history-card summary{cursor:pointer;color:#b8d8ff}
.history-subjects{display:grid;gap:7px;margin-top:10px}
.history-subject-row{display:flex;justify-content:space-between;gap:14px;padding:7px 0;border-bottom:1px solid #172b45}
.history-subject-row:last-child{border-bottom:0}
@media(max-width:720px){.history-kpis{grid-template-columns:repeat(2,minmax(0,1fr))}.history-score{font-size:30px}.trend-item{grid-template-columns:28px minmax(0,1fr) 48px}}


/* Version 9: Schwächenanalyse */
.weakness-kpis{grid-template-columns:repeat(4,minmax(0,1fr))}
.weak-kpi-text{font-size:20px;font-weight:750;margin-top:8px;line-height:1.25}
.weakness-start-card{display:flex;justify-content:space-between;align-items:center;gap:18px}
.weakness-start-card h2{margin:0 0 6px}
.weakness-list{display:grid;grid-template-columns:repeat(auto-fit,minmax(260px,1fr));gap:12px}
.weakness-card{display:grid;gap:10px}
.weakness-card-head,.weakness-card-foot{justify-content:space-between}
.weakness-bar>div{background:linear-gradient(90deg,#ef5350,#f3b34d,#29c36a)}
.weak-pill{background:#3b2415;color:#ffd7a0;border:1px solid #705126}
@media(max-width:720px){.weakness-kpis{grid-template-columns:repeat(2,minmax(0,1fr))}.weakness-start-card{align-items:stretch;flex-direction:column}.weakness-start-card button{width:100%}}


/* Version 10: asynchrone Duelle */
.duel-inline-form{display:grid;grid-template-columns:minmax(0,1fr) auto;gap:10px;align-items:center;max-width:650px}
.duel-action-grid{grid-template-columns:repeat(2,minmax(0,1fr));align-items:start}
.duel-config-grid{display:grid;grid-template-columns:1fr 1fr;gap:12px}
.duel-code-box{margin-top:16px;padding:14px;border:1px solid #31567e;background:#0b1828;border-radius:14px;text-align:center}
.duel-code{font-size:32px;font-weight:900;letter-spacing:.16em;margin:8px 0 12px;color:#b8d8ff}
.duel-code-input{text-transform:uppercase;letter-spacing:.14em;font-weight:800;font-size:20px}
.duel-status{margin-top:10px;min-height:18px}
.duel-list-head{justify-content:space-between;align-items:flex-start}
.duel-list-head h2{margin:0 0 4px}
.duel-list{display:grid;gap:12px}
.duel-card{display:grid;gap:12px}
.duel-card-head{justify-content:space-between;align-items:flex-start}
.duel-card-head h3{margin:8px 0 0}
.duel-player-list{display:grid;gap:7px;padding:10px 0;border-top:1px solid var(--border);border-bottom:1px solid var(--border)}
.duel-player-row{display:flex;justify-content:space-between;gap:12px}
.duel-card-actions{justify-content:flex-end}
@media(max-width:720px){.duel-inline-form,.duel-action-grid,.duel-config-grid{grid-template-columns:1fr}.duel-card-head{align-items:flex-start}.duel-player-row{align-items:flex-start;flex-direction:column;gap:3px}.duel-card-actions button{flex:1}}


/* Version 13: Premium-Abo */
.billing-card{display:grid;grid-template-columns:minmax(0,1.5fr) minmax(240px,.8fr);gap:22px;align-items:center;margin-bottom:24px;border-color:#376ea7;background:linear-gradient(135deg,#0d1d31,#102844)}
.billing-main h2{margin:10px 0 8px}
.billing-status-row{justify-content:space-between;align-items:center}
.billing-price{font-size:20px;font-weight:800;color:#d9ebff}
.billing-actions{display:flex;gap:10px;flex-wrap:wrap;margin-top:16px}
.billing-notice{margin-top:14px;padding:11px 13px;border:1px solid #31567e;border-radius:12px;background:#0b1828;color:#cfe6ff}
.billing-features{display:grid;gap:9px;padding:16px;border:1px solid #31567e;border-radius:14px;background:#0a1726;color:#c9d6e6}
.billing-features strong{color:#fff;margin-bottom:3px}
.premium-pill{background:#2e2347;color:#dcc5ff;border:1px solid #654995}
.premium-locked{opacity:.92}
@media(max-width:720px){.billing-card{grid-template-columns:1fr}.billing-actions button{flex:1}.billing-price{font-size:18px}}

/* v15: Gratis-Test / Paywall nach 20 unterschiedlichen Fragen */
.free-limit-notice{
  margin-top:16px;
  padding:16px;
  border:1px solid rgba(74,144,255,.5);
  border-radius:16px;
  background:rgba(22,64,112,.28);
}
.free-limit-notice strong{display:block;font-size:1.05rem;margin-bottom:8px}
.free-limit-notice p{margin:0 0 14px;line-height:1.5}
.free-limit-notice .primary{width:100%}


/* Version 18: Admin-Verwaltungsdashboard */
.admin-dashboard-card{border-color:#376ea7;background:linear-gradient(135deg,#0d1d31,#102844)}
.admin-dashboard-card h2{margin:8px 0 6px}
.sandbox-pill{background:#3b2d12;color:#ffd98b;border:1px solid #7d6427;font-weight:800;letter-spacing:.08em}
.admin-billing-kpis{grid-template-columns:repeat(4,minmax(0,1fr));margin-top:18px}
.admin-kpi-card{padding:14px;background:#0a1726}
.admin-kpi-card .kpi{font-size:25px;margin-top:5px}
.admin-revenue-trend{display:grid;gap:9px;margin-top:12px}
.admin-revenue-row{display:grid;grid-template-columns:72px minmax(120px,1fr) 100px;gap:10px;align-items:center}
.admin-revenue-track{height:10px;background:#172b45;border-radius:999px;overflow:hidden}
.admin-revenue-track>div{height:100%;background:linear-gradient(90deg,var(--accent),var(--accent2));border-radius:999px}
.admin-revenue-row strong{text-align:right;font-size:13px}
.admin-filter-grid{display:grid;grid-template-columns:minmax(220px,1fr) minmax(180px,260px);gap:12px;margin-top:14px}
.admin-table-wrap{overflow:auto;margin-top:8px}
.admin-data-table{min-width:920px}
.admin-data-table th{white-space:nowrap}
.admin-data-table td{font-size:13px}
.admin-cancel-note{color:#ffd98b;margin-top:6px}
.admin-user-detail{margin-top:18px;padding:18px;border:1px solid #31567e;border-radius:16px;background:#0a1726}
.admin-user-detail h3{margin:8px 0 3px}
.admin-detail-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:12px;margin-top:18px}
.admin-detail-grid>div{display:grid;gap:5px;padding:12px;border:1px solid var(--border);border-radius:12px;background:#0b1828}
.admin-id-list{display:grid;gap:8px;margin-top:14px}
.admin-id-list>div{display:grid;grid-template-columns:150px minmax(0,1fr);gap:10px;align-items:start}
.admin-id-list span{color:var(--muted);font-size:12px}
.admin-id-list code{overflow-wrap:anywhere;color:#cfe6ff}
.admin-export-grid{display:grid;grid-template-columns:minmax(190px,280px) auto;gap:12px;align-items:end;max-width:650px;margin-top:14px}
@media(max-width:1000px){.admin-billing-kpis{grid-template-columns:repeat(2,minmax(0,1fr))}.admin-detail-grid{grid-template-columns:repeat(2,minmax(0,1fr))}}
@media(max-width:720px){.admin-billing-kpis,.admin-filter-grid,.admin-detail-grid,.admin-export-grid{grid-template-columns:1fr}.admin-revenue-row{grid-template-columns:58px minmax(80px,1fr) 82px}.admin-id-list>div{grid-template-columns:1fr}.admin-export-grid button{width:100%}}

/* v20: transparente Abo-Bedingungen direkt unter dem Abschlussbutton */
#billingTerms{margin:13px 0 0;line-height:1.5}