:root{
  font-family:Inter,system-ui,-apple-system,Segoe UI,Roboto,sans-serif;
  color:#10253f;background:#eef3f7;
  --navy:#123b63;--navy2:#0d2c4a;--blue:#dceafa;--line:#d7e1ea;
  --card:#fff;--muted:#617286;--radius:18px;
}
*{box-sizing:border-box}
body{margin:0;min-height:100vh}
button,input,select{font:inherit}
button{cursor:pointer}
.topbar{
  position:sticky;top:0;z-index:20;display:flex;justify-content:space-between;align-items:center;
  background:var(--navy);color:#fff;padding:14px 16px;box-shadow:0 2px 12px #0002
}
.eyebrow{font-size:.68rem;font-weight:800;letter-spacing:.09em;opacity:.8}
.topbar h1{margin:2px 0 0;font-size:1.25rem}
.icon-btn{border:0;background:#ffffff1d;color:#fff;border-radius:12px;width:44px;height:44px;font-size:1.4rem}
main{max-width:820px;margin:auto;padding:16px 14px 90px}
.hidden{display:none!important}
.welcome{margin:6px 2px 16px}
.welcome h2{font-size:1.55rem;margin:0 0 5px}
.welcome p,.panel-heading p{margin:0;color:var(--muted)}
.group-grid{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin-bottom:16px}
.group-card{
  min-height:150px;border:0;border-radius:var(--radius);padding:20px;text-align:left;color:#fff;
  display:flex;flex-direction:column;justify-content:flex-end;box-shadow:0 8px 24px #10253f20
}
.group-card.mini{background:linear-gradient(145deg,#17649a,#123b63)}
.group-card.junior{background:linear-gradient(145deg,#203f6d,#0d2c4a)}
.group-title{font-size:1.35rem;font-weight:850;margin-bottom:4px}
.panel{background:#fff;border-radius:var(--radius);padding:16px;margin:14px 0;box-shadow:0 4px 14px #10253f0c}
.panel-heading{display:flex;justify-content:space-between;align-items:flex-start;margin-bottom:12px}
.panel h3{margin:0 0 3px;font-size:1.05rem}
.quick-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:9px}
.quick-grid button{
  border:1px solid var(--line);background:#f7fafc;color:var(--navy);padding:13px 10px;border-radius:12px;font-weight:750;text-align:left
}
.back-btn{border:0;background:transparent;color:var(--navy);font-weight:800;padding:8px 0 14px}
.search-row{display:grid;grid-template-columns:1fr auto;gap:8px;margin-bottom:12px}
.search-row input,.search-row select{
  min-height:48px;border:1px solid #bfcbd6;border-radius:12px;background:#fff;padding:0 13px
}
.session-list{display:grid;gap:9px}
.session-choice{
  width:100%;display:grid;grid-template-columns:62px 1fr auto;gap:12px;align-items:center;
  border:1px solid var(--line);background:#fff;border-radius:15px;padding:13px;text-align:left
}
.session-number{
  width:54px;height:54px;border-radius:14px;background:var(--blue);display:grid;place-items:center;
  font-size:1.15rem;font-weight:900;color:var(--navy)
}
.session-choice h3{font-size:1rem;margin:0 0 3px}
.session-choice p{font-size:.84rem;margin:0;color:var(--muted)}
.chevron{font-size:1.5rem;color:#8493a2}
.session-hero{
  background:linear-gradient(145deg,var(--navy),var(--navy2));color:#fff;border-radius:var(--radius);
  padding:20px;margin-bottom:12px;box-shadow:0 8px 24px #10253f25
}
.session-hero .meta{font-size:.78rem;font-weight:800;letter-spacing:.04em;opacity:.8}
.session-hero h2{font-size:1.45rem;margin:5px 0 6px}
.session-hero p{margin:0;line-height:1.45}
.mode-switches{
  position:sticky;top:76px;z-index:10;display:grid;grid-template-columns:repeat(3,1fr);gap:5px;
  padding:5px;background:#dfe7ee;border-radius:13px;margin:12px 0
}
.mode-switches button{border:0;background:transparent;padding:10px 5px;border-radius:9px;font-size:.82rem;font-weight:800;color:#526477}
.mode-switches button.active{background:#fff;color:var(--navy);box-shadow:0 2px 6px #0001}
.activity-stack{display:grid;gap:10px}
.activity-card{background:#fff;border-radius:16px;border:1px solid var(--line);overflow:hidden}
.activity-head{
  width:100%;display:grid;grid-template-columns:44px 1fr auto;gap:10px;align-items:center;border:0;background:#fff;
  text-align:left;padding:13px
}
.activity-index{
  width:42px;height:42px;border-radius:12px;background:#e8f0f7;display:grid;place-items:center;font-weight:900;color:var(--navy)
}
.activity-head h3{font-size:1rem;margin:0 0 2px}
.activity-head p{font-size:.79rem;margin:0;color:var(--muted)}
.star-btn{border:0;background:transparent;font-size:1.25rem;color:#9aa6b2;padding:8px}
.star-btn.saved{color:#d69b00}
.activity-body{padding:0 14px 15px;border-top:1px solid #edf1f4}
.activity-body h4{font-size:.83rem;text-transform:uppercase;letter-spacing:.04em;margin:14px 0 6px;color:#53697f}
.activity-body p,.activity-body li{line-height:1.45;font-size:.93rem}
.activity-body ol,.activity-body ul{padding-left:21px}
.callout{border-left:4px solid #7397b6;background:#f5f8fb;padding:10px 11px;border-radius:0 10px 10px 0;margin:9px 0}
.mode-note{background:#fff4d9;border-left-color:#d69b00}
.difficulty-grid{display:grid;gap:6px}
.difficulty{padding:9px 10px;border-radius:10px;background:#f4f7f9;font-size:.88rem}
.library-chip{display:inline-flex;background:#eaf0f5;border-radius:999px;padding:4px 8px;font-size:.72rem;margin:0 4px 4px 0}
.bottom-actions{display:grid;grid-template-columns:1fr 1fr;gap:9px;margin:16px 0}
.bottom-actions button{border:0;border-radius:12px;background:var(--navy);color:#fff;padding:13px;font-weight:800}
.recent-item{display:flex;align-items:center;justify-content:space-between;border-top:1px solid #edf1f4;padding:10px 0}
.recent-item:first-child{border-top:0}
.recent-item button{border:0;background:#eaf1f7;color:var(--navy);padding:9px 12px;border-radius:10px;font-weight:800}
.toast{position:fixed;left:50%;bottom:25px;transform:translateX(-50%);background:#0d2c4a;color:#fff;padding:12px 16px;border-radius:12px;z-index:30;box-shadow:0 6px 20px #0003}
footer{text-align:center;color:#738194;padding:20px;font-size:.82rem}
@media(max-width:560px){
  .group-grid{grid-template-columns:1fr}
  .group-card{min-height:112px}
  .search-row{grid-template-columns:1fr}
  .bottom-actions{grid-template-columns:1fr}
}
@media print{
  .topbar,.back-btn,.mode-switches,.bottom-actions,footer,.star-btn{display:none!important}
  body{background:#fff}
  main{padding:0;max-width:none}
  .activity-body{display:block!important}
  .activity-card,.session-hero{break-inside:avoid;box-shadow:none}
}