:root{
  --purple:#7c3aed;
  --violet:#a855f7;
  --glow:#c084fc;
  --stardust:#f5f3ff;
  --white:#f5f3ff;
  --muted:#8b7aa8;
  --border:rgba(124,58,237,.25);
  --glass:rgba(124,58,237,.08);
  --glass2:rgba(255,255,255,.04);
  --font:'Inter',-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;
  --radius:12px;
  --tr:.22s cubic-bezier(.4,0,.2,1);
  --topbar-h:56px;
}
*,*::before,*::after{
  box-sizing:border-box;
  margin:0;
  padding:0;
}
html{
  width:100%;
  height:100%;
  overflow:hidden;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}
body{
  width:100%;
  height:100%;
  overflow:hidden;
  background:#07061a;
  color:var(--white);
  font-family:var(--font);
  font-size:15px;
  line-height:1.55;
}
body::before{
  content:"";
  position:fixed;
  inset:0;
  z-index:0;
  pointer-events:none;
  background:
    radial-gradient(ellipse 120% 65% at 18% 0%,#0e2a4a 0%,transparent 62%),
    radial-gradient(ellipse 95% 55% at 85% 8%,#2a0f3d 0%,transparent 60%),
    radial-gradient(ellipse 80% 60% at 50% 100%,#1a0e30 0%,transparent 65%),
    linear-gradient(180deg,#060816 0%,#050410 55%,#03020a 100%);
}
body::after{
  content:"";
  position:fixed;
  inset:0;
  z-index:0;
  pointer-events:none;
  background-image:
    linear-gradient(rgba(124,58,237,.04) 1px,transparent 1px),
    linear-gradient(90deg,rgba(124,58,237,.04) 1px,transparent 1px);
  background-size:40px 40px;
}
button{
  font:inherit;
}
.hidden{
  display:none!important;
}
.page-shell{
  position:relative;
  z-index:1;
  width:100%;
  height:100vh;
  height:100dvh;
  display:flex;
  flex-direction:column;
  overflow:hidden;
}
.topbar{
  display:flex;
  align-items:center;
  gap:14px;
  width:100%;
  height:var(--topbar-h);
  min-height:var(--topbar-h);
  padding:0 20px;
  background:linear-gradient(180deg,rgba(12,9,34,.9),rgba(7,6,26,.82));
  backdrop-filter:blur(20px);
  -webkit-backdrop-filter:blur(20px);
  border-bottom:1px solid var(--border);
  position:relative;
  z-index:100;
  flex-shrink:0;
}
.brand{
  display:flex;
  align-items:center;
  gap:8px;
  color:var(--stardust);
  font-family:var(--font);
  font-size:15.5px;
  font-weight:800;
  line-height:1;
  letter-spacing:-.3px;
  text-decoration:none;
  white-space:nowrap;
  flex-shrink:0;
}
.brand:link,
.brand:visited,
.brand:hover,
.brand:active{
  color:var(--stardust);
  text-decoration:none;
}
.brand svg{
  width:22px;
  height:22px;
  flex:0 0 22px;
  display:block;
  filter:drop-shadow(0 0 6px rgba(168,85,247,.55));
}
.topbar-spacer{
  flex:1;
}
.topbar-actions{
  display:flex;
  align-items:center;
  gap:4px;
  flex-shrink:0;
}
.icon-btn{
  position:relative;
  width:36px;
  height:36px;
  display:flex;
  align-items:center;
  justify-content:center;
  padding:0;
  border:0;
  border-radius:9px;
  background:transparent;
  color:var(--muted);
  cursor:pointer;
  transition:background var(--tr),color var(--tr);
}
.icon-btn:hover{
  background:var(--glass);
  color:var(--stardust);
}
.icon-btn svg{
  width:17px;
  height:17px;
  display:block;
}
.icon-dot{
  position:absolute;
  top:7px;
  right:7px;
  width:7px;
  height:7px;
  border-radius:50%;
  background:var(--violet);
  border:1.5px solid #07061a;
}
.lesson-scroll{
  position:relative;
  flex:1;
  min-height:0;
  width:100%;
  overflow-y:auto;
  overflow-x:hidden;
  scrollbar-width:thin;
  scrollbar-color:var(--border) transparent;
}
.lesson-scroll::-webkit-scrollbar{
  width:4px;
}
.lesson-scroll::-webkit-scrollbar-track{
  background:transparent;
}
.lesson-scroll::-webkit-scrollbar-thumb{
  background:var(--border);
  border-radius:4px;
}
.lesson-scroll::-webkit-scrollbar-thumb:hover{
  background:rgba(168,85,247,.5);
}
.lesson-scroll::-webkit-scrollbar-button{
  display:none;
  width:0;
  height:0;
}
.lesson-page{
  width:100%;
  min-height:100%;
  padding:46px 18px 72px;
}
.lesson-layout{
  width:100%;
  display:grid;
  grid-template-columns:46px minmax(0,760px);
  justify-content:center;
  align-items:start;
  column-gap:18px;
}
.back-column{
  width:46px;
  display:flex;
  justify-content:center;
  padding-top:9px;
}
.roadmap-back{
  width:40px;
  height:40px;
  flex:0 0 40px;
  display:grid;
  place-items:center;
  padding:0;
  border:2px solid transparent;
  border-radius:50%;
  background:
    linear-gradient(#0b1027,#0b1027) padding-box,
    linear-gradient(135deg,#38bdf8 0%,#6366f1 48%,#a855f7 100%) border-box;
  cursor:pointer;
  box-shadow:
    0 0 14px rgba(99,102,241,.16),
    inset 0 1px 0 rgba(255,255,255,.03);
  transition:transform .18s ease,filter .18s ease,box-shadow .18s ease;
}
.roadmap-back:hover{
  transform:translateY(-1px);
  filter:brightness(1.12);
  box-shadow:
    0 0 18px rgba(99,102,241,.34),
    0 0 24px rgba(168,85,247,.12);
}
.roadmap-back:active{
  transform:scale(.95);
}
.roadmap-back-arrow{
  width:11px;
  height:11px;
  display:block;
  margin-left:4px;
  border-left:3px solid #d8b4fe;
  border-bottom:3px solid #d8b4fe;
  transform:rotate(45deg);
}
.lesson-shell{
  width:100%;
  min-width:0;
}
.lesson-card{
  width:100%;
  overflow:hidden;
  position:relative;
  border:1px solid var(--border);
  border-radius:var(--radius);
  background:
    linear-gradient(135deg,rgba(14,42,74,.34),rgba(42,15,61,.3)),
    rgba(124,58,237,.07);
  box-shadow:
    0 18px 48px rgba(0,0,0,.28),
    inset 0 1px 0 rgba(255,255,255,.035);
}
.lesson-card::after{
  content:"";
  position:absolute;
  inset:0;
  z-index:0;
  pointer-events:none;
  background-image:
    linear-gradient(rgba(124,58,237,.045) 1px,transparent 1px),
    linear-gradient(90deg,rgba(124,58,237,.045) 1px,transparent 1px);
  background-size:32px 32px;
}
.lesson-card>*{
  position:relative;
  z-index:1;
}
.lesson-cover-art{
  position:relative;
  width:100%;
  min-height:302px;
  overflow:hidden;
  padding:30px 32px 35px;
  background:
    radial-gradient(circle at 73% 22%,rgba(216,70,239,.36),transparent 27%),
    radial-gradient(circle at 34% 96%,rgba(59,130,246,.4),transparent 39%),
    linear-gradient(118deg,rgba(57,48,163,.98),rgba(67,56,202,.97) 37%,rgba(124,58,237,.96) 71%,rgba(126,34,206,.96));
}
.lesson-brand{
  position:relative;
  z-index:3;
  margin-bottom:47px;
  color:rgba(255,255,255,.78);
  font-size:10px;
  font-weight:900;
  letter-spacing:.12em;
}
.lesson-category{
  position:relative;
  z-index:3;
  min-height:15px;
  margin-bottom:8px;
  color:#ddd6fe;
  font-size:10px;
  font-weight:900;
  letter-spacing:.12em;
  text-transform:uppercase;
}
#lessonTitle{
  position:relative;
  z-index:3;
  max-width:590px;
  margin:0;
  color:#fff;
  font-size:clamp(38px,5vw,56px);
  line-height:1.03;
  letter-spacing:-1.8px;
}
#lessonDescription{
  position:relative;
  z-index:3;
  max-width:560px;
  margin:20px 0 0;
  color:rgba(255,255,255,.72);
  font-size:15px;
  line-height:1.6;
}
.lesson-cover-decoration{
  position:absolute;
  right:31px;
  bottom:21px;
  width:190px;
  height:170px;
  pointer-events:none;
}
.lesson-star{
  position:absolute;
  z-index:2;
  right:39px;
  top:60px;
  width:58px;
  height:58px;
  display:grid;
  place-items:center;
  border-radius:50%;
  background:rgba(255,255,255,.1);
  color:#fff;
  font-size:31px;
}
.orbit{
  position:absolute;
  border:1px solid rgba(255,255,255,.15);
  border-radius:50%;
}
.orbit-one{
  width:170px;
  height:69px;
  right:0;
  top:56px;
  transform:rotate(-18deg);
}
.orbit-two{
  width:104px;
  height:170px;
  right:27px;
  top:0;
  transform:rotate(29deg);
}
.lesson-cover-content{
  padding:27px 32px 32px;
  background:rgba(10,7,27,.68);
}
.lesson-meta{
  display:flex;
  align-items:center;
  gap:27px;
  min-height:45px;
  margin-bottom:20px;
  padding-top:14px;
  border-top:1px solid rgba(139,92,246,.17);
  color:var(--muted);
  font-size:12px;
  font-weight:600;
}
.lesson-meta-item{
  display:inline-flex;
  align-items:center;
  gap:7px;
}
.lesson-meta-icon{
  color:var(--glow);
}
.start-learning-button,
.learning-next{
  width:100%;
  min-height:46px;
  padding:11px 18px;
  border:1px solid rgba(192,132,252,.18);
  border-radius:10px;
  background:linear-gradient(90deg,var(--purple),var(--glow));
  color:#fff;
  font-size:13px;
  font-weight:800;
  cursor:pointer;
  box-shadow:
    0 8px 20px rgba(124,58,237,.22),
    inset 0 1px 0 rgba(255,255,255,.08);
  transition:transform .17s ease,box-shadow .17s ease,filter .17s ease;
}
.start-learning-button:hover,
.learning-next:hover:not(:disabled){
  transform:translateY(-1px);
  filter:brightness(1.06);
  box-shadow:0 11px 25px rgba(124,58,237,.32);
}
.start-learning-button:active,
.learning-next:active{
  transform:translateY(0);
}
.learning-next:disabled{
  opacity:.48;
  cursor:not-allowed;
  transform:none;
  filter:none;
}
.learning-experience{
  width:100%;
}
.learning-topbar{
  position:sticky;
  top:0;
  z-index:20;
  width:100%;
  display:grid;
  grid-template-columns:auto minmax(0,1fr) auto;
  align-items:center;
  gap:14px;
  padding:10px 0 18px;
  background:transparent;
}
.learning-progress-wrap{
  min-width:0;
  display:grid;
  grid-template-columns:minmax(0,1fr) 48px;
  align-items:center;
  gap:12px;
}
.learning-progress{
  width:100%;
  height:6px;
  overflow:hidden;
  border-radius:999px;
  background:rgba(255,255,255,.07);
}
.learning-progress-fill{
  width:0;
  height:100%;
  border-radius:inherit;
  background:linear-gradient(90deg,var(--purple),var(--glow));
  transition:width .35s ease;
}
.learning-progress-text{
  color:var(--muted);
  font-size:10px;
  font-weight:700;
  text-align:right;
  white-space:nowrap;
}
.step-nav-button{
  min-width:92px;
  height:38px;
  display:flex;
  align-items:center;
  justify-content:center;
  gap:6px;
  padding:0 12px;
  border:1px solid rgba(168,85,247,.32);
  border-radius:10px;
  background:rgba(124,58,237,.1);
  color:#d8b4fe;
  font-size:11px;
  font-weight:800;
  cursor:pointer;
  transition:
    background var(--tr),
    border-color var(--tr),
    color var(--tr),
    transform var(--tr),
    opacity var(--tr);
}
.step-nav-button svg{
  width:16px;
  height:16px;
  flex:0 0 16px;
}
.step-nav-button:hover:not(:disabled){
  transform:translateY(-1px);
  color:#fff;
  border-color:rgba(192,132,252,.55);
  background:rgba(168,85,247,.18);
}
.step-nav-next{
  background:linear-gradient(90deg,rgba(124,58,237,.3),rgba(168,85,247,.25));
}
.step-nav-button:disabled{
  opacity:.28;
  cursor:not-allowed;
  transform:none;
}
.learning-stage{
  width:100%;
  padding:10px 0 60px;
}
.learning-card{
  position:relative;
  width:100%;
  overflow:hidden;
  padding:30px;
  border:1px solid var(--border);
  border-radius:var(--radius);
  background:
    linear-gradient(135deg,rgba(14,42,74,.34),rgba(42,15,61,.3)),
    rgba(124,58,237,.07);
  box-shadow:
    0 16px 44px rgba(0,0,0,.25),
    inset 0 1px 0 rgba(255,255,255,.03);
}
.learning-card::after{
  content:"";
  position:absolute;
  inset:0;
  pointer-events:none;
  background-image:
    linear-gradient(rgba(124,58,237,.045) 1px,transparent 1px),
    linear-gradient(90deg,rgba(124,58,237,.045) 1px,transparent 1px);
  background-size:32px 32px;
}
.learning-card>*{
  position:relative;
  z-index:1;
}
.learning-label,
.nasa-label{
  display:inline-flex;
  align-items:center;
  margin-bottom:14px;
  padding:4px 8px;
  border:1px solid rgba(168,85,247,.4);
  border-radius:999px;
  background:rgba(168,85,247,.12);
  color:#d8b4fe;
  font-size:9px;
  font-weight:800;
  letter-spacing:.12em;
  text-transform:uppercase;
}
.learning-card h1{
  margin:0 0 14px;
  color:var(--stardust);
  font-size:clamp(29px,4.5vw,43px);
  line-height:1.06;
  letter-spacing:-1.2px;
}
.learning-card h2{
  margin:0 0 14px;
  color:var(--stardust);
  font-size:clamp(23px,4vw,31px);
  line-height:1.15;
}
.learning-card>p{
  margin:0 0 22px;
  color:var(--muted);
  font-size:14px;
  line-height:1.7;
}
.step-hint,
.answer-edit-note{
  margin-top:18px;
  padding:11px 13px;
  border:1px solid rgba(139,122,168,.18);
  border-radius:9px;
  background:rgba(124,58,237,.045);
  color:var(--muted);
  font-size:11px;
  line-height:1.5;
}
.nasa-image{
  width:100%;
  max-height:520px;
  display:block;
  object-fit:cover;
  margin-bottom:21px;
  border:1px solid var(--border);
  border-radius:12px;
  background:#020617;
}
.nasa-loading{
  min-height:240px;
  display:flex;
  flex-direction:column;
  align-items:center;
  justify-content:center;
  text-align:center;
}
.nasa-loading-icon{
  width:48px;
  height:48px;
  display:grid;
  place-items:center;
  margin-bottom:14px;
  border:1px solid rgba(168,85,247,.32);
  border-radius:50%;
  background:rgba(168,85,247,.08);
  color:var(--glow);
  font-size:22px;
}
.nasa-loading p{
  color:var(--muted);
}
.answer-list{
  display:grid;
  gap:10px;
  width:100%;
  margin-top:19px;
}
.answer-button{
  width:100%;
  min-height:50px;
  padding:12px 15px;
  border:1px solid rgba(139,122,168,.25);
  border-radius:10px;
  background:rgba(124,58,237,.07);
  color:#d8d3e8;
  font-size:13px;
  font-weight:600;
  line-height:1.45;
  text-align:left;
  white-space:normal;
  cursor:pointer;
  transition:
    transform .15s ease,
    border-color .15s ease,
    background .15s ease,
    box-shadow .15s ease;
}
.answer-button:hover{
  transform:translateY(-1px);
  color:#fff;
  border-color:rgba(168,85,247,.4);
  background:rgba(168,85,247,.12);
}
.answer-button.answer-selected{
  box-shadow:0 0 0 2px rgba(192,132,252,.14);
}
.answer-button.answer-correct{
  color:#bbf7d0;
  border-color:rgba(34,197,94,.4);
  background:rgba(34,197,94,.1);
}
.answer-button.answer-wrong{
  color:#fecaca;
  border-color:rgba(239,68,68,.4);
  background:rgba(239,68,68,.1);
}
.question-feedback{
  margin-top:16px;
  padding:15px;
  border:1px solid rgba(139,122,168,.2);
  border-radius:10px;
}
.question-feedback strong{
  display:block;
  margin-bottom:5px;
  font-size:14px;
}
.question-feedback p{
  margin:0;
  color:var(--muted);
  font-size:13px;
  line-height:1.55;
}
.feedback-correct{
  border-color:rgba(34,197,94,.32);
  background:rgba(34,197,94,.06);
}
.feedback-correct strong{
  color:#86efac;
}
.feedback-wrong{
  border-color:rgba(239,68,68,.32);
  background:rgba(239,68,68,.06);
}
.feedback-wrong strong{
  color:#fca5a5;
}
.ordering-help{
  color:var(--muted)!important;
  font-size:12px!important;
}
.ordering-list{
  display:grid;
  gap:8px;
  margin:18px 0;
}
.ordering-item{
  display:grid;
  grid-template-columns:31px 1fr auto;
  align-items:center;
  gap:9px;
  min-height:51px;
  padding:9px;
  border:1px solid rgba(139,122,168,.23);
  border-radius:10px;
  background:rgba(124,58,237,.06);
}
.ordering-number{
  width:29px;
  height:29px;
  display:grid;
  place-items:center;
  border-radius:8px;
  color:#d8b4fe;
  background:rgba(168,85,247,.12);
  font-size:11px;
  font-weight:800;
}
.ordering-controls{
  display:flex;
  gap:5px;
}
.ordering-button{
  width:32px;
  height:32px;
  border:1px solid rgba(168,85,247,.3);
  border-radius:8px;
  background:rgba(168,85,247,.1);
  color:#d8b4fe;
  font-size:14px;
  font-weight:800;
  cursor:pointer;
}
.ordering-button:hover:not(:disabled){
  background:rgba(168,85,247,.18);
  border-color:rgba(168,85,247,.48);
}
.ordering-button:disabled{
  opacity:.3;
  cursor:not-allowed;
}
.ordering-item.ordering-correct{
  border-color:rgba(34,197,94,.4);
  background:rgba(34,197,94,.08);
}
.activity-check-button{
  margin-top:15px;
}
.key-facts{
  display:grid;
  gap:9px;
  margin:19px 0 23px;
}
.key-fact{
  display:grid;
  grid-template-columns:22px 1fr;
  gap:8px;
  align-items:start;
  padding:12px;
  border:1px solid rgba(139,122,168,.2);
  border-radius:10px;
  background:rgba(124,58,237,.06);
}
.key-fact span{
  color:var(--glow);
  font-size:15px;
}
.key-fact p{
  margin:0;
  color:#cfc8dc;
  font-size:13px;
  line-height:1.55;
}
.completion-card{
  text-align:center;
}
.completion-icon{
  width:60px;
  height:60px;
  display:grid;
  place-items:center;
  margin:0 auto 17px;
  border-radius:50%;
  background:linear-gradient(135deg,var(--purple),var(--glow));
  color:#fff;
  font-size:27px;
  font-weight:900;
  box-shadow:0 0 25px rgba(168,85,247,.24);
}
.completion-card .learning-label{
  margin-left:auto;
  margin-right:auto;
}
.completion-card>p{
  max-width:560px;
  margin-left:auto;
  margin-right:auto;
}
.completion-xp{
  display:inline-flex;
  align-items:center;
  gap:6px;
  margin:2px auto 21px;
  padding:8px 14px;
  border:1px solid rgba(168,85,247,.3);
  border-radius:999px;
  background:rgba(168,85,247,.1);
  color:#d8b4fe;
  font-size:12px;
}
.completion-xp span{
  color:var(--glow);
}
.completion-help{
  color:var(--muted)!important;
  font-size:11px!important;
}
@media(max-width:760px){
  .topbar{
    padding:0 12px;
  }
  .lesson-page{
    padding:22px 10px 48px;
  }
  .lesson-layout{
    display:block;
  }
  .back-column{
    width:100%;
    padding:0;
    margin-bottom:14px;
    justify-content:flex-start;
  }
  .roadmap-back{
    width:37px;
    height:37px;
  }
  .lesson-cover-art{
    min-height:285px;
    padding:26px 22px 30px;
  }
  .lesson-brand{
    margin-bottom:40px;
  }
  #lessonTitle{
    font-size:40px;
  }
  #lessonDescription{
    font-size:14px;
  }
  .lesson-cover-decoration{
    right:14px;
    bottom:12px;
    transform:scale(.78);
    transform-origin:bottom right;
  }
  .lesson-cover-content{
    padding:23px 22px 27px;
  }
  .learning-card{
    padding:23px 18px;
  }
  .learning-topbar{
    grid-template-columns:44px minmax(0,1fr) 44px;
    gap:8px;
  }
  .step-nav-button{
    min-width:44px;
    width:44px;
    padding:0;
  }
  .step-nav-button span{
    display:none;
  }
  .learning-progress-wrap{
    grid-template-columns:minmax(0,1fr) 44px;
    gap:8px;
  }
}
@media(max-width:430px){
  .topbar{
    padding:0 9px;
  }
  .brand{
    gap:6px;
    font-size:13px;
  }
  .brand svg{
    width:21px;
    height:21px;
    flex-basis:21px;
  }
  .lesson-page{
    padding:17px 8px 38px;
  }
  .back-column{
    margin-bottom:12px;
  }
  .roadmap-back{
    width:35px;
    height:35px;
  }
  .roadmap-back-arrow{
    width:10px;
    height:10px;
    border-left-width:2px;
    border-bottom-width:2px;
  }
  .lesson-cover-art{
    min-height:255px;
    padding:21px 18px 25px;
  }
  .lesson-brand{
    margin-bottom:31px;
  }
  #lessonTitle{
    font-size:34px;
  }
  #lessonDescription{
    font-size:13px;
  }
  .lesson-cover-decoration{
    opacity:.6;
    transform:scale(.64);
  }
  .lesson-cover-content{
    padding:19px 18px 23px;
  }
  .lesson-meta{
    gap:16px;
    flex-wrap:wrap;
  }
  .learning-topbar{
    gap:6px;
  }
  .learning-progress-wrap{
    gap:6px;
  }
  .learning-progress-text{
    font-size:9px;
  }
  .learning-card{
    padding:20px 14px;
  }
  .ordering-item{
    grid-template-columns:28px 1fr;
  }
  .ordering-controls{
    grid-column:2;
  }
}