.sidebar-overlay{position:fixed;top:0;right:0;bottom:0;left:0;z-index:200;background:#000000c7;-webkit-backdrop-filter:blur(6px);backdrop-filter:blur(6px)}.sidebar-mobile{position:absolute;top:0;left:0;bottom:0;width:min(20rem,90vw);display:flex;flex-direction:column;gap:.3rem;padding:1.1rem;background:#0e0e0e;border-right:1px solid var(--border);box-shadow:var(--shadow-lg);overflow-y:auto}.xp-toast-container{position:fixed;top:5rem;right:1rem;z-index:9999;display:flex;flex-direction:column;gap:.65rem;pointer-events:none}.xp-toast{display:flex;align-items:center;gap:.75rem;min-width:13rem;padding:.8rem 1rem;border:1px solid var(--border-strong);border-radius:var(--r);background:#141414;color:var(--text);box-shadow:var(--shadow)}.xp-toast-icon{font-size:1.05rem}.xp-toast-amount{color:#fff;font-family:var(--font-mono);font-weight:700}.xp-toast-reason{color:var(--text-muted);font-size:.72rem}.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}.ai-tutor-root{position:relative;z-index:1000}.ai-fab{position:fixed;right:1.4rem;bottom:1.4rem;z-index:1000;display:inline-flex;align-items:center;gap:.75rem;min-height:3.35rem;padding:.62rem .9rem .62rem .65rem;border:1px solid rgba(255,255,255,.18);border-radius:999px;background:#0e0e0ef0;color:var(--text);box-shadow:0 18px 48px #00000073;-webkit-backdrop-filter:blur(14px);backdrop-filter:blur(14px);transition:transform .16s var(--ease),border-color .16s var(--ease),background .16s var(--ease)}.ai-fab:hover{transform:translateY(-2px);border-color:#ffffff57;background:#191919f5}.ai-fab:focus-visible,.ai-icon-btn:focus-visible,.ai-quick-btn:focus-visible,.ai-send-btn:focus-visible,.ai-input:focus-visible{outline:2px solid rgba(147,197,253,.9);outline-offset:2px}.ai-fab-icon{display:inline-flex;align-items:center;justify-content:center;width:2.1rem;height:2.1rem;border-radius:999px;background:#fff;color:#080808;flex-shrink:0}.ai-fab-copy{display:flex;flex-direction:column;align-items:flex-start;gap:.05rem;line-height:1.1}.ai-fab-kicker{color:var(--text-dim);font-size:.66rem}.ai-fab-label{color:var(--text);font-family:var(--font-mono);font-size:.72rem;font-weight:700;letter-spacing:.08em;text-transform:uppercase}.ai-panel{position:fixed;right:1.25rem;bottom:1.25rem;z-index:1001;width:min(27.5rem,calc(100vw - 1.5rem));height:min(38rem,calc(100vh - 2.5rem));display:flex;flex-direction:column;overflow:hidden;background:#0c0c0cfa;border:1px solid rgba(255,255,255,.16);border-radius:18px;box-shadow:0 32px 90px #000000ad;animation:ai-panel-in .22s cubic-bezier(.22,1,.36,1) forwards;transform-origin:bottom right}.ai-panel-expanded{right:50%;bottom:50%;width:min(72rem,calc(100vw - 3rem));height:min(44rem,calc(100vh - 3rem));transform:translate(50%,50%);transform-origin:center;box-shadow:0 40px 100px #000000c7,0 0 0 1px #ffffff14}@keyframes ai-panel-in{0%{opacity:0;transform:scale(.96) translateY(12px)}to{opacity:1;transform:scale(1) translateY(0)}}@keyframes ai-panel-expanded-in{0%{opacity:.92;transform:translate(50%,50%) scale(.98)}to{opacity:1;transform:translate(50%,50%) scale(1)}}.ai-panel-expanded{animation:ai-panel-expanded-in .22s cubic-bezier(.22,1,.36,1) forwards}.ai-close-btn{background:#ff464614!important;border-color:#ff464633!important;color:#ff7878e6!important}.ai-close-btn:hover{background:#ff46462e!important;border-color:#ff464666!important;color:#f88!important}.ai-panel-header,.ai-input-row,.ai-quick-prompts{flex-shrink:0}.ai-panel-header{display:flex;align-items:center;justify-content:space-between;padding:.9rem 1rem;border-bottom:1px solid var(--border);background:#ffffff05}.ai-panel-heading,.ai-panel-actions{display:flex;align-items:center;gap:.65rem;min-width:0}.ai-panel-actions{flex-shrink:0;gap:.4rem}.ai-avatar{display:flex;align-items:center;justify-content:center;width:2.1rem;height:2.1rem;border-radius:var(--r-sm);background:#ffffff14;color:var(--text)}.ai-panel-title{color:var(--text);font-weight:700;font-size:.88rem}.ai-panel-sub{color:var(--text-muted);font-size:.7rem;max-width:16rem;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.ai-icon-btn,.ai-send-btn{display:inline-flex;align-items:center;justify-content:center;border-radius:var(--r-sm)}.ai-icon-btn{width:2rem;height:2rem;border:1px solid var(--border);background:#ffffff08;color:var(--text-muted)}.ai-messages{display:flex;flex:1;flex-direction:column;gap:.65rem;padding:1rem;overflow-y:auto}.ai-message{display:flex}.ai-message-user{justify-content:flex-end}.ai-bubble{max-width:88%;padding:.72rem .9rem;border-radius:var(--r);font-size:.86rem;line-height:1.65}.ai-bubble-user{background:#fff;color:#080808;border-bottom-right-radius:3px}.ai-bubble-assistant{background:#ffffff0a;color:var(--text-muted);border:1px solid var(--border);border-bottom-left-radius:3px}.ai-typing{display:flex;align-items:center;gap:.35rem;padding:.65rem .85rem}.ai-typing span:not(.sr-only){width:.36rem;height:.36rem;border-radius:999px;background:var(--text-dim);animation:ai-typing 1s ease-in-out infinite}.ai-typing span:not(.sr-only):nth-of-type(3){animation-delay:.12s}.ai-typing span:not(.sr-only):nth-of-type(4){animation-delay:.24s}@keyframes ai-typing{0%,80%,to{opacity:.3;transform:translateY(0)}40%{opacity:1;transform:translateY(-3px)}}.ai-quick-prompts{display:flex;flex-direction:column;gap:.4rem;padding:.72rem 1rem;border-top:1px solid var(--border)}.ai-quick-btn{padding:.6rem .8rem;border:1px solid var(--border);border-radius:var(--r);background:#ffffff05;color:var(--text-muted);text-align:left;font-size:.82rem}.ai-quick-btn:hover{background:#ffffff0d;color:var(--text);border-color:var(--border-hover)}.ai-input-row{display:flex;gap:.6rem;padding:.85rem 1rem 1rem;border-top:1px solid var(--border)}.ai-input{flex:1;border:1px solid var(--border);border-radius:var(--r);background:#ffffff08;color:var(--text);padding:.72rem .9rem}.ai-send-btn{width:2.5rem;height:2.5rem;border:1px solid var(--border-strong);background:#ffffff12;color:var(--text)}.ai-send-btn:hover{background:#fff;color:#080808}.ai-send-btn:disabled{opacity:.45;cursor:not-allowed}.exam-section{display:flex;flex-direction:column}.exam-section-header{margin-bottom:1.25rem}.exam-q{padding:1.35rem}.exam-q-header{display:flex;align-items:center;justify-content:space-between;margin-bottom:.85rem}.exam-q-text{color:var(--text);font-size:.96rem;font-weight:600;line-height:1.6;margin-bottom:1rem}.exam-answer-area{display:flex;flex-direction:column;gap:.75rem}.exam-textarea,.exam-user-answer,.exam-sample-answer{border:1px solid var(--border);border-radius:var(--r);background:#ffffff05}.exam-textarea{width:100%;min-height:8rem;padding:.95rem 1rem;color:var(--text);line-height:1.7;resize:vertical}.exam-user-answer{padding:1rem}.exam-answer-pre{white-space:pre-wrap;color:var(--text-muted);font-family:var(--font-mono);font-size:.81rem}.exam-sample-answer{padding:.9rem 1rem}.exam-sample-answer summary{display:flex;align-items:center;justify-content:space-between;color:var(--text-muted);font-weight:600;list-style:none}.exam-sample-answer summary::-webkit-details-marker{display:none}.fc-controls,.questions-list{display:flex;gap:1rem}.fc-controls{justify-content:center;margin-top:1.4rem}.questions-list{flex-direction:column}.question-card{padding:1.35rem}.question-text{margin-bottom:1rem;color:var(--text);font-size:1rem;font-weight:600}.options-list{display:flex;flex-direction:column;gap:.65rem}.question-explain{margin-top:1rem}.quiz-result{margin-bottom:1.5rem}.quiz-result-score{margin-bottom:.5rem;font-size:1.05rem}.xpbar{min-width:0}.xpbar-compact{display:flex;align-items:center;gap:.7rem;min-width:0;text-decoration:none}.xpbar-icon,.xpbar-rank-icon{flex-shrink:0;line-height:1}.xpbar-icon{font-size:1rem}.xpbar-copy,.xpbar-rank-copy{min-width:0}.xpbar-copy{display:flex;flex-direction:column;gap:.2rem}.xpbar-topline,.xpbar-progress-meta,.xpbar-header{display:flex;align-items:center;gap:.6rem}.xpbar-topline{min-width:0}.xpbar-total,.xpbar-rank-label,.xpbar-rank-total,.xpbar-progress-meta,.xpbar-next,.xpbar-max,.xpbar-streak-copy,.xpbar-streak{font-family:var(--font-mono)}.xpbar-total,.xpbar-rank-label{font-size:.7rem;font-weight:700}.xpbar-streak{color:#ffffff61;font-size:.62rem;white-space:nowrap}.xpbar-track{overflow:hidden;background:#ffffff12}.xpbar-track-compact{width:5rem;height:2px;border-radius:999px}.xpbar-fill{height:100%;border-radius:inherit;background:#ffffffad;transition:width .5s var(--ease)}.xpbar-full{padding:1.1rem 1.25rem;border:1px solid var(--border);border-radius:var(--r-lg);background:#ffffff05}.xpbar-header{justify-content:space-between;align-items:flex-start;margin-bottom:.85rem}.xpbar-rank{display:flex;align-items:center;gap:.8rem;min-width:0}.xpbar-rank-icon{font-size:2rem}.xpbar-rank-label{font-size:1.05rem}.xpbar-rank-total,.xpbar-progress-meta,.xpbar-next,.xpbar-max,.xpbar-streak-copy{color:var(--text-muted);font-size:.68rem}.xpbar-streak-pill{display:inline-flex;align-items:center;gap:.5rem;padding:.42rem .7rem;border:1px solid var(--border);border-radius:var(--r-sm);background:#ffffff08;flex-shrink:0}.xpbar-streak-icon{display:inline-flex;align-items:center;justify-content:center;width:1.35rem;height:1.35rem;border-radius:999px;background:#ffffff0f;color:#ffffff80;font-family:var(--font-mono);font-size:.68rem;font-weight:700}.xpbar-progress-meta{justify-content:space-between;margin-bottom:.45rem;flex-wrap:wrap}.xpbar-track-full{height:2px;border-radius:999px}.xpbar-next,.xpbar-max{margin-top:.4rem}.xpbar-max{color:#ffffff6b}.nav-left{display:flex;align-items:center;gap:.75rem;min-width:0;flex-shrink:0}.nav-countdown-wrap{min-width:0}.sidebar-mobile-xp{padding-bottom:1rem;margin-bottom:.8rem;border-bottom:1px solid var(--border)}.sidebar-mobile-extra{margin-top:.35rem;padding-top:.85rem;border-top:1px solid var(--border)}@media (max-width: 520px){.ai-panel{right:.6rem;bottom:.6rem;width:calc(100vw - 1.2rem);height:min(40rem,calc(100vh - 1.2rem))}.ai-panel-expanded{right:.6rem;bottom:.6rem;width:calc(100vw - 1.2rem);height:min(40rem,calc(100vh - 1.2rem));transform:none}.ai-fab{right:.75rem;bottom:.75rem}.ai-panel-sub{max-width:11rem}.xpbar-topline{flex-wrap:wrap}.xpbar-progress-meta{flex-direction:column;align-items:flex-start}}@media (max-width: 768px){.xpbar-header{flex-direction:column;align-items:stretch}.xpbar-streak-pill{align-self:flex-start}}.unit-page{padding:1.9rem 0 4.5rem}.unit-page-header{display:flex;gap:1rem;align-items:flex-start;margin-bottom:1rem}.unit-page-icon{display:inline-flex;align-items:center;justify-content:center;width:4rem;height:4rem;border-radius:1.25rem;background:#ffffff0d;font-size:2rem;flex-shrink:0}.unit-page-title{color:var(--text-accent);font-family:var(--font-display);font-size:clamp(2rem,4vw,2.8rem);font-weight:700;letter-spacing:-.04em;line-height:1.08}.unit-page-desc{max-width:60ch;margin:.6rem 0 .9rem;color:var(--text-muted)}.unit-page-meta{display:flex;flex-wrap:wrap;gap:.55rem;align-items:center}.unit-start-panel{display:flex;align-items:center;justify-content:space-between;gap:1rem;margin:0 0 1.2rem;padding:1.1rem;border:1px solid var(--border);border-radius:1.1rem;background:#ffffff09}.unit-start-label{display:block;margin-bottom:.35rem;color:var(--text-soft);font-family:var(--font-mono);font-size:.66rem;font-weight:800;letter-spacing:.1em;text-transform:uppercase}.unit-start-panel h2{color:var(--text-accent);font-size:1.05rem;font-weight:800;line-height:1.35}.unit-start-panel p{margin-top:.35rem;color:var(--text-muted);font-size:.88rem;line-height:1.6}.unit-progress-bar{margin-bottom:1.5rem}.lessons-list{display:flex;flex-direction:column;gap:.8rem}.lesson-row{display:flex;align-items:center;gap:.9rem;padding:1rem 1.1rem}.lesson-row:hover{transform:translate(2px)}.lesson-done{border-color:#6fd3a838}.lesson-row-num{min-width:1.8rem;color:var(--text-soft)}.lesson-row-icon{display:inline-flex;align-items:center;justify-content:center;width:2.5rem;height:2.5rem;border-radius:.95rem;background:#ffffff0a}.lesson-row-info{flex:1;min-width:0}.lesson-row-title{display:block;color:var(--text);font-size:.96rem;font-weight:700}.lesson-row-meta{display:flex;align-items:center;gap:.3rem;margin-top:.25rem;color:var(--text-soft);font-size:.75rem}.lesson-row-action{color:var(--text-muted);font-size:.8rem;font-weight:700;white-space:nowrap}@media (max-width: 640px){.unit-page{padding-top:1.2rem}.unit-page-header{flex-direction:column}.unit-start-panel{align-items:stretch;flex-direction:column}.unit-start-panel .btn{justify-content:center;width:100%}.lesson-row{flex-wrap:wrap}.lesson-row-action{width:100%;padding-left:5.2rem}}@keyframes skel-shimmer{0%{background-position:200% center}to{background-position:-200% center}}.skel{border-radius:.85rem;background:linear-gradient(90deg,#ffffff0a,#ffffff1a,#ffffff0a);background-size:200% 100%;animation:skel-shimmer 1.4s linear infinite}.skel-line{height:.8rem;border-radius:999px}.skel-line-sm{width:38%}.skel-line-md{width:60%}.skel-line-lg{width:76%}.skel-line-xl{width:92%}.skel-circle{width:1.8rem;height:1.8rem;border-radius:999px;flex-shrink:0}.skel-icon{width:2.5rem;height:2.5rem;border-radius:.95rem}.skel-badge{width:4.2rem;height:1.2rem;border-radius:999px}.skel-badge-sm{width:3.2rem}.skel-progress{height:.45rem;width:100%;border-radius:999px}.skel-lesson-row,.skel-unit-card,.skel-search-card,.skel-stats{border:1px solid var(--border);border-radius:var(--r-lg);background:linear-gradient(180deg,#101d30eb,#0c1828f0);box-shadow:var(--shadow-sm)}.skel-lesson-row{display:flex;align-items:center;gap:.9rem;padding:1rem 1.1rem}.skel-lesson-row-content{flex:1;display:flex;flex-direction:column;gap:.55rem}.skel-unit-card{padding:1.25rem}.skel-unit-top{display:flex;align-items:center;justify-content:space-between;margin-bottom:1rem}.skel-search-card{padding:1rem 1.1rem}.skel-stats{padding:1.25rem}@media (prefers-reduced-motion: reduce){.skel{animation:none}}.learning-game{display:grid;gap:.75rem}.learning-game-engine{min-width:0}.learning-game-intro{display:flex;align-items:flex-start;justify-content:space-between;gap:1rem;padding:.85rem 1rem;border:1px solid rgba(255,255,255,.14);border-radius:.75rem;background:linear-gradient(135deg,#ffffff14,#ffffff06),#050d1bb8;box-shadow:0 16px 44px #00000038}.learning-game-intro h2{margin-top:.25rem;color:var(--text-accent);font-size:clamp(1.1rem,2vw,1.45rem);font-weight:950;line-height:1.05}.learning-game-intro p{max-width:58ch;margin-top:.35rem;color:var(--text-muted);font-size:.86rem;line-height:1.5}.learning-game-xp,.game-status-row,.binary-value-row,.atom-facts{display:flex;align-items:center;gap:.45rem;color:var(--text-muted);font-family:var(--font-mono);font-size:.74rem}.learning-game-xp{flex-shrink:0;padding:.58rem .78rem;border:1px solid rgba(246,200,120,.22);border-radius:.65rem;background:linear-gradient(135deg,#f6c87833,#f6c8780f);color:#fff4d6;font-weight:950}.learning-game-panel{display:grid;gap:1rem}.phaser-game-frame{position:relative;width:100%;aspect-ratio:16 / 9;min-height:18rem;border:1px solid rgba(255,255,255,.24);border-radius:.65rem;overflow:hidden;background:radial-gradient(circle at 20% 10%,rgba(103,232,249,.16),transparent 30%),radial-gradient(circle at 80% 20%,rgba(167,139,250,.14),transparent 32%),#020617;box-shadow:inset 0 0 42px #00000061,0 24px 80px #00000057}.phaser-game-frame:before{content:"";position:absolute;top:0;right:0;bottom:0;left:0;z-index:2;pointer-events:none;border:1px solid rgba(255,255,255,.08);border-radius:inherit;box-shadow:inset 0 0 26px #67e8f91f,inset 0 0 0 4px #ffffff09}.phaser-game-frame:after{content:"";position:absolute;top:0;right:0;bottom:0;left:0;z-index:3;pointer-events:none;background:linear-gradient(rgba(255,255,255,.035) 1px,transparent 1px),linear-gradient(90deg,rgba(255,255,255,.028) 1px,transparent 1px);background-size:100% 3px,3px 100%;mix-blend-mode:screen;opacity:.24}.phaser-game-host{position:absolute;top:0;right:0;bottom:0;left:0}.phaser-game-host canvas{display:block;width:100%!important;height:100%!important}.binary-arena{position:relative;overflow:hidden;padding:.15rem}.binary-arena.pulse .binary-target,.binary-arena.pulse .binary-value-row{animation:game-pop .26s ease-out}.binary-rain{position:absolute;top:0;right:0;bottom:0;left:0;z-index:0;pointer-events:none;opacity:.22;overflow:hidden}.binary-rain span{position:absolute;left:var(--left);top:-2rem;color:#6ea8feb3;font-family:var(--font-mono);font-size:.78rem;animation:binary-fall 4.5s linear infinite;animation-delay:var(--delay)}.binary-arena>:not(.binary-rain){position:relative;z-index:1}.game-status-row,.binary-value-row,.atom-facts{justify-content:space-between;padding:.8rem .9rem;border:1px solid var(--border);border-radius:.9rem;background:#ffffff06}.binary-target,.atom-target{display:grid;gap:.2rem;justify-items:center;padding:1.1rem;border:1px solid rgba(110,168,254,.24);border-radius:1rem;background:#6ea8fe14;text-align:center}.binary-target span,.atom-target span{color:var(--text-soft);font-family:var(--font-mono);font-size:.68rem;letter-spacing:.1em;text-transform:uppercase}.binary-target strong,.atom-target strong{color:var(--text-accent);font-family:var(--font-display);font-size:clamp(2rem,5vw,3rem);line-height:1}.atom-target small{color:var(--text-muted);font-family:var(--font-mono);font-size:.85rem}.binary-value-row strong{color:var(--text);font-size:1rem}.binary-value-row strong.is-correct{color:#86efac}.binary-grid{display:grid;grid-template-columns:repeat(8,minmax(0,1fr));gap:.55rem}.binary-bit{display:grid;gap:.35rem;justify-items:center;min-height:4.4rem;padding:.75rem .35rem;border:1px solid var(--border);border-radius:.85rem;background:#ffffff09;color:var(--text-muted);transition:transform .16s var(--ease),border-color .16s var(--ease),background-color .16s var(--ease)}.binary-bit:hover{transform:translateY(-1px);border-color:var(--border-hover)}.binary-bit.active{border-color:#6ea8fe6b;background:#6ea8fe29;color:var(--text-accent);box-shadow:0 0 24px #6ea8fe21}.binary-bit span{font-family:var(--font-display);font-size:1.2rem;font-weight:800}.binary-bit small{color:var(--text-soft);font-family:var(--font-mono);font-size:.66rem}.game-action-row{display:flex;flex-wrap:wrap;gap:.65rem}.game-action-row .btn:disabled{cursor:not-allowed;opacity:.48}.learning-game-complete{display:grid;grid-template-columns:auto minmax(0,1fr) auto;align-items:center;gap:.9rem;padding:1rem;border:1px solid rgba(134,239,172,.24);border-radius:.75rem;background:linear-gradient(135deg,#22c55e29,#22c55e0e)}.learning-game-complete-icon{display:inline-flex;align-items:center;justify-content:center;width:2.4rem;height:2.4rem;border-radius:.8rem;background:#22c55e1f;color:#86efac}.learning-game-complete h3{color:var(--text-accent);font-size:1rem}.learning-game-complete p{margin-top:.2rem;color:var(--text-muted);font-size:.85rem;line-height:1.55}.circuit-board{position:relative;min-height:10rem;border:1px solid var(--border);border-radius:1rem;background:linear-gradient(90deg,rgba(255,255,255,.04) 1px,transparent 1px),linear-gradient(rgba(255,255,255,.04) 1px,transparent 1px),#ffffff06;background-size:32px 32px;overflow:hidden}.circuit-game.shake .circuit-build-card{animation:circuit-shake .42s ease}.circuit-board-parallel .wire-line-top,.circuit-board-parallel .wire-line-bottom{left:18%;right:18%}.wire-branch{position:absolute;left:28%;right:28%;top:50%;height:4.8rem;transform:translateY(-50%);border:3px solid rgba(110,168,254,.65);border-left:0;border-right:0}.battery-symbol,.lamp-symbol,.wire-line{position:absolute}.battery-symbol{left:10%;top:50%;width:2.6rem;height:3.4rem;transform:translateY(-50%);border-left:4px solid #e5e7eb;border-right:8px solid #e5e7eb}.wire-line{height:3px;background:#6ea8febd}.wire-line-top{left:13%;right:13%;top:31%}.wire-line-bottom{left:13%;right:13%;bottom:31%}.lamp-symbol{top:50%;width:3.1rem;height:3.1rem;border:3px solid #facc15;border-radius:999px;transform:translateY(-50%);background:#facc1514}.lamp-symbol:before,.lamp-symbol:after{content:"";position:absolute;left:50%;top:50%;width:2.35rem;height:2px;background:#facc15}.lamp-symbol:before{transform:translate(-50%,-50%) rotate(42deg)}.lamp-symbol:after{transform:translate(-50%,-50%) rotate(-42deg)}.lamp-symbol-left{left:42%}.lamp-symbol-right{right:16%}.circuit-build-card{display:grid;gap:.7rem;padding:.9rem;border:1px solid var(--border);border-radius:1rem;background:#ffffff06}.circuit-round-head{display:flex;align-items:flex-start;gap:.55rem}.circuit-round-head svg{margin-top:.12rem;color:var(--text-muted);flex-shrink:0}.circuit-round-head h3{color:var(--text);font-size:.95rem;line-height:1.45}.circuit-round-head p{margin-top:.25rem;color:var(--text-muted);font-size:.82rem;line-height:1.55}.component-tray,.circuit-slots{display:grid;gap:.6rem}.component-tray{grid-template-columns:repeat(4,minmax(0,1fr))}.component-chip,.circuit-slot{display:inline-flex;align-items:center;justify-content:center;gap:.45rem;min-height:3.1rem;border:1px solid var(--border);border-radius:.85rem;background:#ffffff09;color:var(--text-muted);font-size:.82rem;font-weight:750;text-transform:capitalize;transition:transform .16s var(--ease),border-color .16s var(--ease),background-color .16s var(--ease),color .16s var(--ease)}.component-chip{cursor:grab}.component-chip:hover,.component-chip.selected,.circuit-slot.filled{transform:translateY(-1px);border-color:#6ea8fe5c;background:#6ea8fe1a;color:var(--text)}.component-glyph{position:relative;display:inline-flex;width:1.35rem;height:1.35rem;flex-shrink:0}.component-cell .component-glyph{border-left:3px solid #e5e7eb;border-right:6px solid #e5e7eb}.component-switch .component-glyph:before{content:"";position:absolute;left:.1rem;right:.1rem;top:.65rem;height:2px;background:#93c5fd;transform:rotate(-24deg)}.component-lamp .component-glyph{border:2px solid #facc15;border-radius:999px}.component-lamp .component-glyph:before,.component-lamp .component-glyph:after{content:"";position:absolute;left:50%;top:50%;width:1rem;height:2px;background:#facc15}.component-lamp .component-glyph:before{transform:translate(-50%,-50%) rotate(42deg)}.component-lamp .component-glyph:after{transform:translate(-50%,-50%) rotate(-42deg)}.component-resistor .component-glyph:before{content:"";position:absolute;top:.45rem;right:.1rem;bottom:.45rem;left:.1rem;border-top:3px solid #fb7185;border-bottom:3px solid #fb7185}.circuit-slots{grid-template-columns:repeat(4,minmax(0,1fr));margin-top:.2rem;padding:.7rem;border:1px dashed rgba(255,255,255,.12);border-radius:1rem}.circuit-slots-parallel{background:linear-gradient(90deg,transparent 48%,rgba(110,168,254,.12) 48%,rgba(110,168,254,.12) 52%,transparent 52%),#ffffff04}.circuit-slot:not(.filled){border-style:dashed;color:var(--text-soft)}.circuit-power-meter{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:.4rem}.circuit-power-meter span{height:.55rem;border-radius:999px;background:#ffffff12;overflow:hidden}.circuit-power-meter span.active{background:linear-gradient(90deg,#67e8f9,#86efac);box-shadow:0 0 20px #67e8f938}.game-choice-grid{display:grid;gap:.5rem}.game-choice{padding:.75rem .85rem;border:1px solid var(--border);border-radius:.8rem;background:#ffffff06;color:var(--text-muted);text-align:left;font-size:.86rem;line-height:1.45;transition:border-color .16s var(--ease),background-color .16s var(--ease),color .16s var(--ease)}.game-choice:hover,.game-choice.selected{border-color:#6ea8fe57;background:#6ea8fe1a;color:var(--text)}.atom-stage{position:relative;display:flex;align-items:center;justify-content:center;flex-wrap:wrap;gap:.4rem;min-height:9.5rem;padding:1rem;border:1px solid var(--border);border-radius:1rem;background:radial-gradient(circle at 50% 50%,rgba(110,168,254,.15),transparent 34%),#ffffff06}.atom-stage-correct{border-color:#86efac52;box-shadow:inset 0 0 40px #22c55e14}.atom-stage:before{content:"";position:absolute;top:1.8rem;right:1.8rem;bottom:1.8rem;left:1.8rem;border:1px dashed rgba(255,255,255,.12);border-radius:999px;pointer-events:none}.electron-orbit{position:absolute;left:50%;top:50%;border:1px solid rgba(103,232,249,.26);border-radius:999px;pointer-events:none}.electron-orbit:before{content:"";position:absolute;right:-.25rem;top:50%;width:.5rem;height:.5rem;border-radius:999px;background:#67e8f9;box-shadow:0 0 16px #67e8f98c}.electron-orbit-one{width:6rem;height:6rem;margin:-3rem 0 0 -3rem;animation:orbit-spin 5s linear infinite}.electron-orbit-two{width:9rem;height:4.8rem;margin:-2.4rem 0 0 -4.5rem;transform:rotate(-24deg);animation:orbit-spin-tilt 7s linear infinite}.particle{position:relative;z-index:1;display:inline-flex;align-items:center;justify-content:center;width:1.65rem;height:1.65rem;border-radius:999px;color:#0b0b0b;font-family:var(--font-mono);font-size:.68rem;font-weight:900;text-transform:uppercase;animation:particle-enter .24s ease-out}.particle-p{background:#fb7185}.particle-n{background:#facc15}.particle-e{background:#67e8f9}.particle-launcher{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:.6rem}.particle-launch{min-height:2.8rem;border:1px solid var(--border);border-radius:.85rem;background:#ffffff09;color:var(--text);font-size:.82rem;font-weight:750;transition:transform .16s var(--ease),border-color .16s var(--ease),background-color .16s var(--ease)}.particle-launch:hover{transform:translateY(-1px);border-color:var(--border-hover)}.particle-launch-protons{background:#fb71851a}.particle-launch-neutrons{background:#facc151a}.particle-launch-electrons{background:#67e8f91a}.atom-counters{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:.7rem}.atom-counter{display:grid;gap:.5rem;justify-items:center;padding:.85rem;border:1px solid var(--border);border-radius:.95rem;background:#ffffff06}.atom-counter span{color:var(--text-muted);font-size:.78rem}.atom-counter strong{color:var(--text-accent);font-family:var(--font-display);font-size:1.45rem}.atom-counter div{display:flex;gap:.4rem}.atom-counter button{display:inline-flex;align-items:center;justify-content:center;width:2rem;height:2rem;border:1px solid var(--border);border-radius:.65rem;background:#ffffff0a;color:var(--text);font-size:1rem;font-weight:800}@media (max-width: 700px){.learning-game-intro,.learning-game-complete{grid-template-columns:1fr}.learning-game-intro{flex-direction:column}.binary-grid{grid-template-columns:repeat(4,minmax(0,1fr))}.atom-counters{grid-template-columns:1fr}.component-tray,.circuit-slots,.particle-launcher{grid-template-columns:repeat(2,minmax(0,1fr))}.game-action-row .btn,.learning-game-complete .btn{width:100%;justify-content:center}}@media (max-width: 420px){.binary-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.component-tray,.circuit-slots,.particle-launcher{grid-template-columns:1fr}}@keyframes binary-fall{0%{transform:translateY(-2rem)}to{transform:translateY(26rem)}}@keyframes game-pop{0%{transform:scale(1)}50%{transform:scale(1.018)}to{transform:scale(1)}}@keyframes circuit-shake{0%,to{transform:translate(0)}25%{transform:translate(-7px)}50%{transform:translate(7px)}75%{transform:translate(-4px)}}@keyframes orbit-spin{to{transform:rotate(360deg)}}@keyframes orbit-spin-tilt{to{transform:rotate(336deg)}}@keyframes particle-enter{0%{opacity:0;transform:scale(.4) translateY(12px)}to{opacity:1;transform:scale(1) translateY(0)}}.ds-shell{display:flex;flex-direction:column;gap:2rem}.ds-empty{text-align:center;padding:3rem;color:var(--text-muted)}.ds-card{border:1px solid var(--border);border-radius:var(--r-lg);background:#090d1899;overflow:hidden}.ds-card-header{display:flex;align-items:center;gap:.75rem;padding:.9rem 1.25rem;border-bottom:1px solid var(--border);background:#ffffff05}.ds-card-num{font-family:var(--font-mono);font-size:.62rem;font-weight:700;color:#93c5fd;background:#3b82f61f;border:1px solid rgba(59,130,246,.25);padding:2px 8px;border-radius:4px;letter-spacing:.06em}.ds-card-title{font-size:.88rem;font-weight:700;color:var(--text)}.ds-card-body{padding:1.5rem 1.25rem;overflow-x:auto}.d-box{border:1.5px solid var(--border-strong);border-radius:8px;background:#0d1220e6;padding:.5rem .85rem;font-size:.78rem;font-weight:600;color:var(--text);text-align:center;white-space:nowrap;line-height:1.4;display:flex;align-items:center;justify-content:center}.d-box.blue{border-color:#3b82f666;background:#3b82f614;color:#93c5fd}.d-box.green{border-color:#10b98166;background:#10b98114;color:#6ee7b7}.d-box.yellow{border-color:#f59e0b66;background:#f59e0b14;color:#fcd34d}.d-box.red{border-color:#ef444466;background:#ef444414;color:#fca5a5}.d-box.purple{border-color:#8b5cf666;background:#8b5cf614;color:#c4b5fd}.d-box.ghost{border-color:var(--border);background:#ffffff05;color:var(--text-muted)}.d-row{display:flex;align-items:center;gap:.5rem;flex-wrap:wrap}.d-col{display:flex;flex-direction:column;align-items:center;gap:.5rem}.d-grid{display:grid;gap:.75rem}.d-arrow{display:flex;align-items:center;gap:0;position:relative;color:var(--text-dim);font-size:.68rem;flex-shrink:0}.d-arrow-line{height:1.5px;background:currentColor;min-width:28px;flex:1}.d-arrow-head{width:0;height:0;border-top:5px solid transparent;border-bottom:5px solid transparent;border-left:8px solid currentColor;flex-shrink:0}.d-arrow-head-left{width:0;height:0;border-top:5px solid transparent;border-bottom:5px solid transparent;border-right:8px solid currentColor;flex-shrink:0}.d-arrow.blue{color:#3b82f6}.d-arrow.green{color:#10b981}.d-arrow.yellow{color:#f59e0b}.d-arrow.red{color:#ef4444}.d-arrow.dashed .d-arrow-line{background:none;border-top:1.5px dashed currentColor}.d-varrow{display:flex;flex-direction:column;align-items:center;gap:0;color:var(--text-dim);flex-shrink:0}.d-varrow-line{width:1.5px;background:currentColor;min-height:20px;flex:1}.d-varrow-head{width:0;height:0;border-left:5px solid transparent;border-right:5px solid transparent;border-top:8px solid currentColor}.d-varrow-head-up{width:0;height:0;border-left:5px solid transparent;border-right:5px solid transparent;border-bottom:8px solid currentColor}.d-varrow.blue{color:#3b82f6}.d-varrow.green{color:#10b981}.d-varrow.yellow{color:#f59e0b}.d-varrow.red{color:#ef4444}.d-label{font-size:.68rem;color:var(--text-muted);font-family:var(--font-mono);text-align:center;line-height:1.4}.d-label.blue{color:#60a5fa}.d-label.green{color:#34d399}.d-label.yellow{color:#fcd34d}.d-label.red{color:#f87171}.d-divider{border:none;border-top:1px dashed var(--border);margin:1rem 0}.d-group{border:1px dashed var(--border-strong);border-radius:10px;padding:.75rem;position:relative}.d-group-label{position:absolute;top:-.5rem;left:.75rem;font-size:.6rem;font-family:var(--font-mono);font-weight:700;color:var(--text-muted);background:#090d18f2;padding:0 6px;letter-spacing:.08em;text-transform:uppercase}.d-cylinder{display:flex;flex-direction:column;align-items:center;min-width:80px}.d-cylinder-cap{width:100%;height:14px;border-radius:50%;border:1.5px solid var(--border-strong);background:#0d1220e6}.d-cylinder-body{width:100%;border-left:1.5px solid var(--border-strong);border-right:1.5px solid var(--border-strong);background:#0d1220e6;display:flex;align-items:center;justify-content:center;padding:.4rem;font-size:.72rem;font-weight:600;color:var(--text);text-align:center;min-height:44px}.d-cylinder-bottom{width:100%;height:14px;border-radius:50%;border:1.5px solid var(--border-strong);background:#0d1220e6;margin-top:-7px}.ds-points{display:flex;flex-direction:column;gap:.35rem;margin-top:1rem;padding-top:1rem;border-top:1px solid var(--border)}.ds-point{display:flex;align-items:flex-start;gap:.5rem;font-size:.76rem;color:var(--text-muted);line-height:1.5}.ds-point-dot{width:5px;height:5px;border-radius:50%;background:#3b82f6;margin-top:.4rem;flex-shrink:0}.lesson-page{padding:1.9rem 0 4.5rem}.lesson-page-wide .container-sm{max-width:min(96vw,1680px)}.lesson-page-wide .lesson-header-left{max-width:64rem}.lesson-page-wide .lesson-body{padding:1.45rem 1.65rem}.breadcrumb{display:flex;align-items:center;flex-wrap:wrap;gap:.4rem;margin-bottom:1rem;color:var(--text-soft);font-size:.82rem}.breadcrumb a:hover{color:var(--text-accent)}.lesson-shell{display:flex;flex-direction:column;gap:1rem}.lesson-header{display:flex;justify-content:space-between;align-items:flex-start;gap:1rem;padding:1.2rem 0}.lesson-header-left{max-width:48rem;min-width:0}.lesson-title{margin-top:.85rem;color:var(--text-accent);font-family:var(--font-display);font-size:clamp(2rem,4vw,3rem);font-weight:700;line-height:1.08;letter-spacing:-.04em}.lesson-meta{display:flex;flex-wrap:wrap;gap:.55rem;margin-top:.9rem;align-items:center}.lesson-header-actions{display:flex;align-items:center;justify-content:flex-end;flex-wrap:wrap;gap:.65rem;flex-shrink:0}.lp-subject-return{white-space:nowrap}.lesson-tabs{display:grid;gap:.45rem;padding:.35rem;border:1px solid var(--border);border-radius:1.2rem;background:#ffffff08}.lesson-tab{position:relative;display:inline-flex;align-items:center;justify-content:center;gap:.45rem;min-width:0;min-height:2.8rem;padding:.65rem .8rem;border:0;border-radius:.95rem;background:transparent;color:var(--text-muted);font-size:.84rem;font-weight:600;text-align:center;transition:color .18s var(--ease),background-color .18s var(--ease),transform .18s var(--ease)}.lesson-tab:hover{color:var(--text);background:#ffffff0d}.lesson-tab.active{color:var(--text-accent);background:#6ea8fe1f}.lesson-tab-indicator{position:absolute;top:0;right:0;bottom:0;left:0;border:1px solid rgba(110,168,254,.25);border-radius:inherit;pointer-events:none}.lesson-body{padding:1.2rem;min-height:20rem}.lesson-content-stack{display:flex;flex-direction:column;gap:1rem}.lesson-content-stack h3{color:var(--text-accent);font-size:1rem;font-weight:700}.lesson-nav{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:.8rem;margin-top:1.5rem}.lesson-nav-btn{display:flex;align-items:center;gap:.7rem;min-width:0;padding:1rem 1.05rem;border:1px solid var(--border);border-radius:1rem;background:#ffffff08;transition:transform .18s var(--ease),border-color .18s var(--ease),background-color .18s var(--ease)}.lesson-nav-btn:hover{transform:translateY(-1px);border-color:var(--border-hover);background:#ffffff0d}.lesson-nav-btn-right{justify-content:space-between;text-align:right}.lesson-nav-label{color:var(--text-soft);font-family:var(--font-mono);font-size:.66rem;letter-spacing:.09em;text-transform:uppercase}.lesson-nav-title{color:var(--text);font-size:.88rem;font-weight:600;overflow-wrap:anywhere}.lp-complete-btn{flex-shrink:0}.lp-xp-hint{display:inline-flex;align-items:center;flex-wrap:wrap;gap:.45rem;padding:.65rem .8rem;border:1px solid rgba(246,200,120,.22);border-radius:999px;background:#f6c87814;color:#fff0cd}.lesson-loading-state{display:flex;flex-direction:column;gap:1rem}@media (max-width: 820px){.lesson-header{flex-direction:column;align-items:flex-start}.lesson-header-actions{justify-content:flex-start}.lesson-tabs{gap:.4rem}.lesson-nav{grid-template-columns:1fr}}@media (max-width: 640px){.lesson-page-wide .container-sm{max-width:none}.lesson-page-wide .lesson-body{padding:1rem .9rem}.lesson-page{padding:1.35rem 0 3.2rem}.breadcrumb{gap:.3rem;margin-bottom:.85rem;font-size:.76rem}.lesson-shell{gap:.8rem}.lesson-header{gap:.85rem;padding:.6rem 0 .2rem}.lesson-title{margin-top:.7rem;font-size:clamp(1.7rem,8vw,2.2rem)}.lesson-meta{gap:.45rem;margin-top:.75rem}.lesson-tabs{gap:.35rem;padding:.3rem;border-radius:1rem;grid-template-columns:repeat(2,minmax(0,1fr))!important}.lesson-tab{min-height:2.6rem;padding:.7rem;font-size:.78rem;line-height:1.25}.lesson-body{padding:1rem .9rem;border-radius:1rem;min-height:0}.lesson-nav{margin-top:1.1rem;gap:.65rem}.lesson-nav-btn{gap:.6rem;padding:.9rem}}@media (max-width: 560px){.lesson-page{padding-top:1.2rem}.lesson-title{font-size:1.85rem}.lesson-tabs{grid-template-columns:1fr!important}.lesson-body{padding:.95rem}.lesson-header-actions,.lp-complete-btn,.lp-subject-return{width:100%}.lesson-header-actions .btn{justify-content:center}.lesson-tab{justify-content:flex-start}.lesson-nav-btn,.lesson-nav-btn-right{justify-content:flex-start;text-align:left}}@media (max-width: 420px){.breadcrumb{font-size:.72rem}.lesson-title{font-size:1.65rem;line-height:1.12}.lesson-meta{align-items:flex-start}.lesson-tab{font-size:.76rem}.lesson-body{padding:.85rem .8rem}}
