:root{
  --paper:#FBF7EC;
  --paper-line:#E4DCC6;
  --ink:#26314B;
  --ink-soft:#5B6478;
  --forest:#2F6B4F;
  --forest-dark:#234f3b;
  --coral:#E8613C;
  --sun:#F2B705;
  --sky:#4A90A4;
  --plum:#7B5EA7;
  --white:#FFFFFF;
}
*{box-sizing:border-box;}
html,body{height:100%;}
body{
  margin:0;
  background:var(--forest-dark);
  font-family:'Nunito',sans-serif;
  color:var(--ink);
  display:flex;
  min-height:100vh;
}
.spine{width:14px;background:repeating-linear-gradient(180deg,var(--forest) 0 18px, var(--forest-dark) 18px 22px);flex-shrink:0;}

.tabs{width:150px;flex-shrink:0;background:var(--forest-dark);padding:28px 0 0 0;display:flex;flex-direction:column;gap:10px;position:sticky;top:0;height:100vh;}
.tabs .brand{font-family:'Baloo 2',sans-serif;color:var(--paper);font-size:15px;font-weight:700;text-align:center;padding:0 10px 22px 10px;line-height:1.25;border-bottom:2px dashed rgba(251,247,236,0.25);margin:0 12px 8px 12px;}
.tabs .brand span{display:block;font-family:'Caveat',cursive;font-size:20px;font-weight:600;color:var(--sun);margin-top:2px;}
.tabs .brand-logo{max-width:100%;max-height:56px;display:block;margin:0 auto;}
.tab-btn{display:block;text-decoration:none;font-family:'Baloo 2',sans-serif;font-weight:600;font-size:14.5px;color:var(--paper);background:transparent;padding:12px 10px 12px 18px;border-radius:10px 0 0 10px;position:relative;transition:transform .15s ease;opacity:0.82;}
.tab-btn .dot{display:inline-block;width:9px;height:9px;border-radius:50%;margin-right:8px;vertical-align:middle;}
.tab-btn:hover{opacity:1;transform:translateX(2px);}
.tab-btn.active{background:var(--paper);color:var(--ink);opacity:1;box-shadow:-3px 3px 0 rgba(0,0,0,0.18);}

.page-wrap{flex:1;background:var(--paper);background-image:linear-gradient(var(--paper-line) 1px, transparent 1px);background-size:100% 34px;background-position:0 92px;min-height:100vh;position:relative;padding:36px 44px 60px 52px;}
.margin-rule{position:absolute;left:96px;top:0;bottom:0;width:2px;background:rgba(232,97,60,0.25);}
.top-strip{display:flex;align-items:baseline;justify-content:space-between;margin-bottom:26px;flex-wrap:wrap;gap:10px;}
h1.page-title{font-family:'Baloo 2',sans-serif;font-size:34px;margin:0;color:var(--ink);}
.kicker{font-family:'Caveat',cursive;font-size:20px;color:var(--coral);font-weight:600;margin:0 0 2px 2px;}
.subtitle{color:var(--ink-soft);font-size:15px;margin-top:4px;}

.grid{display:grid;gap:18px;}
.grid.cols-2{grid-template-columns:repeat(auto-fit,minmax(260px,1fr));}
.grid.cols-4{grid-template-columns:repeat(auto-fit,minmax(180px,1fr));}
.card{background:var(--white);border:2px solid var(--ink);border-radius:14px;padding:18px 20px;box-shadow:4px 4px 0 rgba(38,49,75,0.12);}
.subject-card{display:block;text-decoration:none;color:inherit;cursor:pointer;transition:transform .15s ease;}
.subject-card:hover{transform:translate(-2px,-2px);box-shadow:6px 6px 0 rgba(38,49,75,0.18);}
.subject-card h3{font-family:'Baloo 2',sans-serif;margin:6px 0 4px;font-size:19px;}
.subject-card p{margin:0;color:var(--ink-soft);font-size:14px;}
.badge{display:inline-block;font-family:'IBM Plex Mono',monospace;font-size:11px;padding:3px 8px;border-radius:20px;color:var(--white);font-weight:600;}

.lesson{background:var(--white);border:2px solid var(--ink);border-radius:12px;margin-bottom:14px;overflow:hidden;}
.lesson-head{display:flex;align-items:center;justify-content:space-between;padding:14px 18px;cursor:pointer;font-family:'Baloo 2',sans-serif;font-weight:600;font-size:16px;}
.lesson-head .chev{transition:transform .2s ease;color:var(--coral);font-size:14px;}
.lesson.open .chev{transform:rotate(90deg);}
.lesson-body{max-height:0;overflow:hidden;transition:max-height .25s ease;}
.lesson-body-inner{padding:0 18px 18px;color:var(--ink-soft);font-size:14.5px;line-height:1.6;}
.lesson-body-inner strong{color:var(--ink);}
.note{font-family:'Caveat',cursive;font-size:18px;color:var(--sky);font-weight:600;border-left:3px dashed var(--sky);padding-left:10px;margin-top:10px;}
.video-wrap{position:relative;width:100%;max-width:560px;aspect-ratio:16/9;margin:14px 0;border-radius:10px;overflow:hidden;border:2px solid var(--ink);background:#000;}
.video-wrap iframe, .video-wrap video{position:absolute;top:0;left:0;width:100%;height:100%;border:0;}

.resource-row{display:flex;align-items:center;gap:12px;padding:12px 16px;background:var(--white);border:2px solid var(--ink);border-radius:10px;margin-bottom:10px;}
.resource-row .icon{width:34px;height:34px;border-radius:8px;display:flex;align-items:center;justify-content:center;font-size:16px;color:white;flex-shrink:0;}
.resource-row .info strong{display:block;font-family:'Baloo 2',sans-serif;font-size:15px;}
.resource-row .info span{font-size:13px;color:var(--ink-soft);}

.quiz-box{background:var(--white);border:2px solid var(--ink);border-radius:14px;padding:24px;max-width:640px;}
.q-progress{font-family:'IBM Plex Mono',monospace;font-size:12px;color:var(--ink-soft);margin-bottom:8px;}
.q-text{font-family:'Baloo 2',sans-serif;font-size:20px;margin:4px 0 18px;}
.choice{display:block;width:100%;text-align:left;padding:12px 16px;margin-bottom:10px;border:2px solid var(--ink);border-radius:10px;background:var(--paper);cursor:pointer;font-family:'Nunito',sans-serif;font-size:15px;font-weight:600;color:var(--ink);transition:background .15s ease, transform .1s ease;}
.choice:hover{transform:translateX(3px);}
.choice.correct{background:var(--forest);color:white;border-color:var(--forest-dark);}
.choice.wrong{background:var(--coral);color:white;border-color:#a8402a;}
.quiz-picker a{font-family:'Baloo 2',sans-serif;font-weight:600;font-size:15px;padding:10px 18px;border:2px solid var(--ink);border-radius:10px;background:white;cursor:pointer;margin:6px 10px 6px 0;text-decoration:none;color:var(--ink);display:inline-block;}
.quiz-picker a:hover{background:var(--sun);}
.stamp{display:inline-flex;align-items:center;justify-content:center;flex-direction:column;width:96px;height:96px;border-radius:50%;border:3px dashed var(--ink);font-family:'Baloo 2',sans-serif;font-size:12px;text-align:center;padding:6px;transform:rotate(-6deg);background:var(--white);}
.stamp b{font-size:20px;font-family:'IBM Plex Mono',monospace;}
.next-btn,.primary-btn{font-family:'Baloo 2',sans-serif;font-weight:700;font-size:15px;color:white;background:var(--forest);border:none;border-radius:10px;padding:12px 22px;cursor:pointer;box-shadow:3px 3px 0 rgba(0,0,0,0.2);text-decoration:none;display:inline-block;}
.next-btn:hover,.primary-btn:hover{background:var(--forest-dark);}

.meter-track{height:18px;background:#EFE9D8;border:2px solid var(--ink);border-radius:20px;overflow:hidden;}
.meter-fill{height:100%;background:linear-gradient(90deg,var(--sun),var(--coral));}
.progress-row{display:flex;align-items:center;gap:16px;margin-bottom:16px;}
.progress-row .label{width:140px;font-family:'Baloo 2',sans-serif;font-weight:600;}
.progress-row .meter-track{flex:1;}
.progress-row .score{width:60px;text-align:right;font-family:'IBM Plex Mono',monospace;font-size:13px;color:var(--ink-soft);}
.stamps-row{display:flex;gap:16px;flex-wrap:wrap;margin-top:18px;}
.empty-note{font-family:'Caveat',cursive;font-size:20px;color:var(--ink-soft);}

@media (max-width:720px){
  .tabs{width:96px;}
  .tab-btn{font-size:12.5px;padding:10px 6px 10px 12px;}
  .page-wrap{padding:26px 18px 50px 24px;}
  .margin-rule{left:60px;}
  h1.page-title{font-size:26px;}
}