:root{--bg-deep: #060b14;--bg-surface: #0c1626;--bg-subcard: #09111e;--border-subtle: #1e293b;--border-highlight: #38bdf8;--text-primary: #f8fafc;--text-secondary: #cbd5e1;--text-muted: #94a3b8;--accent-blue: #0284c7;--accent-cyan: #38bdf8;--accent-amber: #f59e0b;--accent-emerald: #10b981;--accent-rose: #e11d48}*{box-sizing:border-box}html,body{margin:0;padding:0;background-color:var(--bg-deep);color:var(--text-primary);font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Oxygen,Ubuntu,Cantarell,sans-serif;line-height:1.5;overflow-x:hidden}a{color:var(--accent-cyan)}.app-shell{min-height:100vh;display:flex;flex-direction:column}.top-navbar{background:#0c1626f5;border-bottom:1px solid var(--border-subtle);position:sticky;top:0;z-index:40;-webkit-backdrop-filter:blur(8px);backdrop-filter:blur(8px)}.top-navbar-inner{max-width:1440px;margin:0 auto;padding:10px 18px;display:flex;align-items:center;justify-content:space-between;flex-wrap:wrap;gap:12px}.brand-cluster{display:flex;align-items:center;gap:10px}.brand-logo-img{width:38px;height:38px;border-radius:9px;object-fit:cover;box-shadow:0 2px 10px #00000073;border:1px solid rgba(255,255,255,.18);flex-shrink:0}.brand-puck-icon{width:38px;height:38px;border-radius:10px;background:linear-gradient(135deg,#0284c7,#0369a1);display:flex;align-items:center;justify-content:center;font-size:1.25rem;box-shadow:0 2px 8px #0284c759}.brand-title{font-weight:800;font-size:1.15rem;letter-spacing:-.01em;color:#fff}.brand-subtitle{font-size:.74rem;color:var(--text-muted)}.main-nav-tabs{display:flex;align-items:center;gap:6px;flex-wrap:wrap}.nav-tab-btn{background:transparent;border:1px solid transparent;color:var(--text-secondary);padding:7px 12px;border-radius:8px;font-size:.86rem;font-weight:600;cursor:pointer;transition:all .15s ease}.nav-tab-btn:hover{background:#132238;color:#fff}.nav-tab-btn.active{background:var(--accent-blue);color:#fff;border-color:var(--accent-cyan)}.utility-nav-actions{display:flex;align-items:center;gap:8px;flex-wrap:wrap}.return-lesson-banner{background:#0c243c;border-top:1px solid #0284c7;padding:8px 18px;display:flex;justify-content:space-between;align-items:center;flex-wrap:wrap;gap:10px;font-size:.86rem;color:#e0f2fe}.main-content-container{max-width:1440px;width:100%;margin:0 auto;padding:18px;flex:1}.surface-card{background:var(--bg-surface);border:1px solid var(--border-subtle);border-radius:12px;box-shadow:0 4px 16px #00000047}.surface-subcard{background:var(--bg-subcard);border:1px solid var(--border-subtle);border-radius:10px}.interactive-card{transition:border-color .15s ease,transform .15s ease}.interactive-card:hover{border-color:#334155}.cards-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:16px}.two-col-grid{display:grid;grid-template-columns:1fr 1fr;gap:16px}.three-col-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}.two-col-rink-layout{display:grid;grid-template-columns:1.55fr 1fr;gap:16px;align-items:start}@media(max-width:1024px){.two-col-rink-layout,.two-col-grid,.three-col-grid{grid-template-columns:1fr}}@media(max-width:600px){.main-content-container{padding:10px}.top-navbar-inner{padding:8px 10px}.cards-grid{grid-template-columns:1fr}}.btn{display:inline-flex;align-items:center;justify-content:center;gap:6px;padding:7px 13px;border-radius:8px;font-size:.85rem;font-weight:600;cursor:pointer;border:1px solid transparent;transition:all .14s ease;font-family:inherit}.btn:disabled{opacity:.45;cursor:not-allowed}.btn-primary{background:var(--accent-blue);color:#fff;border-color:var(--accent-cyan)}.btn-primary:hover:not(:disabled){background:#0369a1}.btn-secondary{background:#132238;color:#e2e8f0;border-color:#334155}.btn-secondary:hover:not(:disabled){background:#1e293b;border-color:var(--accent-cyan)}.btn-ghost{background:#09111e;color:#cbd5e1;border-color:#1e293b}.btn-ghost:hover:not(:disabled){background:#132238;color:#fff}.concept-inline-pill{background:#0c243c;color:#7dd3fc;border:1px solid #0284c7;padding:5px 11px;border-radius:999px;font-size:.82rem;font-weight:600;cursor:pointer;transition:all .14s ease}.concept-inline-pill:hover{background:#0284c7;color:#fff}.badge{display:inline-block;padding:3px 9px;border-radius:999px;font-size:.74rem;font-weight:700;letter-spacing:.02em}.badge-info{background:#38bdf826;color:#38bdf8;border:1px solid rgba(56,189,248,.35)}.badge-success{background:#10b98129;color:#34d399;border:1px solid rgba(16,185,129,.35)}.badge-warning{background:#f59e0b29;color:#fbbf24;border:1px solid rgba(245,158,11,.35)}.badge-danger{background:#f43f5e2e;color:#fb7185;border:1px solid rgba(244,63,94,.38)}.text-input,.select-input{background:#09111e;color:#f8fafc;border:1px solid #334155;border-radius:8px;padding:8px 12px;font-size:.9rem;font-family:inherit}.text-input:focus,.select-input:focus{outline:2px solid var(--accent-cyan);border-color:transparent}.info-banner{background:#0284c71f;border:1px solid rgba(56,189,248,.35);border-radius:8px;padding:12px 14px;font-size:.88rem;color:#e0f2fe;line-height:1.55}.modal-backdrop{position:fixed;top:0;right:0;bottom:0;left:0;background:#030712d1;display:flex;align-items:center;justify-content:center;padding:16px;z-index:80}.modal-panel{background:var(--bg-surface);border:1px solid #334155;border-radius:14px;width:100%;max-width:680px;max-height:90vh;display:flex;flex-direction:column;overflow:hidden;box-shadow:0 20px 50px #0009}.modal-panel-wide{max-width:960px}.modal-header{padding:16px 20px;border-bottom:1px solid var(--border-subtle);display:flex;justify-content:space-between;align-items:center;gap:12px}.modal-body{padding:20px;overflow-y:auto}.app-footer{border-top:1px solid var(--border-subtle);background:#09111e;margin-top:28px}.app-footer-inner{max-width:1440px;margin:0 auto;padding:14px 18px;display:flex;justify-content:space-between;align-items:center;flex-wrap:wrap;gap:10px;font-size:.84rem;color:var(--text-muted)}