:root{--color-on-accent: #3d2a00;--color-knew: #2d6a4f;--color-knew-bg: rgba(45, 106, 79, .07);--color-unsure: #b7800a;--color-unsure-bg: rgba(183, 128, 10, .07);--color-forgot: #c0392b;--color-forgot-bg: rgba(192, 57, 43, .07);--shadow-card: 0 4px 20px rgba(0, 0, 0, .09), 0 1px 4px rgba(0, 0, 0, .05);--shadow-overlay: 0 16px 48px rgba(0, 0, 0, .16);--header-h: 56px;--swap-out: .13s;--swap-in: .17s}body.dark{--color-knew: #52b788;--color-knew-bg: rgba(82, 183, 136, .12);--color-unsure: #faba40;--color-unsure-bg: rgba(250, 186, 64, .12);--color-forgot: #ff6b6b;--color-forgot-bg: rgba(255, 107, 107, .12);--shadow-card: 0 4px 20px rgba(0, 0, 0, .3), 0 1px 4px rgba(0, 0, 0, .2);--shadow-overlay: 0 16px 48px rgba(0, 0, 0, .5)}kbd{display:inline-block;background:var(--color-surface);border:1px solid var(--color-border);border-radius:4px;padding:0 .35rem;font-family:var(--font-mono);font-size:.65rem;line-height:1.6;color:var(--color-text-secondary)}.loading-screen,.error-screen{position:fixed;inset:0;top:var(--header-h);display:flex;flex-direction:column;align-items:center;justify-content:center;gap:1rem;background:var(--color-bg);z-index:89;font-size:.9rem;color:var(--color-text-secondary)}.loading-spinner{width:32px;height:32px;border-radius:50%;border:2px solid var(--color-border);border-top-color:var(--color-accent);animation:spin .7s linear infinite}@keyframes spin{to{transform:rotate(360deg)}}.error-icon{font-size:2rem}.mode-panel{padding-top:1rem;min-height:calc(100vh - var(--header-h))}.start-overlay{position:fixed;top:var(--header-h);left:0;right:0;bottom:0;z-index:90;background:var(--color-bg);overflow-y:auto;display:flex;flex-direction:column;align-items:center;padding:2rem 1.25rem 3rem;gap:1.5rem}.start-overlay.hidden{display:none}.start-hero{text-align:center;padding-top:1rem}.start-hero__label{font-size:.75rem;letter-spacing:.1em;text-transform:uppercase;color:var(--color-accent-text);margin-bottom:.5rem;font-weight:700}body.dark .start-hero__label{color:var(--color-accent)}.start-hero__title{font-size:clamp(2rem,6vw,3rem);font-weight:700;color:var(--color-text-primary);letter-spacing:-.01em;line-height:1.2}.start-hero__divider{width:48px;height:2px;margin:1rem auto 0;background:var(--color-accent)}.start-card{width:min(560px,100%);background:var(--color-surface);border:1px solid var(--color-border);border-radius:12px;box-shadow:var(--shadow-overlay);padding:1.75rem}.start-card__title{font-size:1.15rem;font-weight:700;margin-bottom:.35rem}.start-card__desc{font-size:.85rem;color:var(--color-text-secondary);margin-bottom:1.25rem}.start-block{margin-bottom:1.25rem}.start-label{display:block;font-size:.7rem;font-weight:700;letter-spacing:.05em;text-transform:uppercase;color:var(--color-text-secondary);margin-bottom:.5rem}.start-cats{display:flex;flex-wrap:wrap;gap:.5rem}.start-cat{padding:.4rem .9rem;border-radius:100px;border:1px solid var(--color-border);background:var(--color-bg);font-size:.85rem;color:var(--color-text-secondary);cursor:pointer;transition:all .15s}.start-cat:hover{border-color:var(--color-accent);color:var(--color-text-primary)}.start-cat.active{background:var(--color-accent);border-color:var(--color-accent);color:var(--color-on-accent, var(--color-accent-text));font-weight:700}.start-count{width:100%;padding:.6rem .85rem;border:1px solid var(--color-border);border-radius:8px;font-size:.95rem;background:var(--color-bg);color:var(--color-text-primary);appearance:none;cursor:pointer;outline:none;transition:border-color .15s}.start-count:focus{border-color:var(--color-accent)}.start-meta{font-size:.8rem;color:var(--color-accent-text);margin-bottom:1.1rem;min-height:1.2em;font-weight:600}body.dark .start-meta{color:var(--color-accent)}.study-area{padding:1rem 1.25rem 3rem;max-width:640px;margin:0 auto;display:flex;flex-direction:column;align-items:center;gap:1.25rem}.progress-strip{width:100%;height:4px;background:var(--color-border);border-radius:100px;overflow:hidden}.progress-fill{height:100%;width:0%;background:var(--color-accent);border-radius:100px;transition:width .35s ease}.deck-nav-row{width:100%;display:flex;align-items:center;justify-content:space-between;gap:.75rem}.deck-center{flex:1;display:flex;flex-direction:column;align-items:center;gap:.5rem}.deck-indicator{font-size:.85rem;color:var(--color-text-secondary);font-weight:600}.mastery-dots{display:flex;gap:4px;justify-content:center;flex-wrap:wrap;min-height:8px}.m-dot{width:7px;height:7px;border-radius:50%;background:var(--color-border);transition:background .2s;flex-shrink:0}.m-dot.knew{background:var(--color-knew)}.m-dot.unsure{background:var(--color-unsure)}.m-dot.forgot{background:var(--color-forgot)}.m-dot.current{background:var(--color-text-primary);box-shadow:0 0 0 2px var(--color-border)}.nav-btn{width:44px;height:44px;border-radius:50%;border:1px solid var(--color-border);background:var(--color-surface);font-size:1.4rem;color:var(--color-text-secondary);cursor:pointer;transition:all .15s;flex-shrink:0;display:flex;align-items:center;justify-content:center;box-shadow:var(--shadow-card)}.nav-btn:hover{background:var(--color-accent);color:var(--color-on-accent, var(--color-accent-text));border-color:var(--color-accent)}.nav-btn:disabled{opacity:.25;cursor:default;pointer-events:none}.card-scene{width:100%;aspect-ratio:16 / 9;perspective:1200px;cursor:pointer;user-select:none}.card-scene.is-swapping{pointer-events:none}.card-body{width:100%;height:100%;position:relative;transform-style:preserve-3d;transition:transform .52s cubic-bezier(.4,.2,.2,1);border-radius:12px}.card-body.flipped{transform:rotateY(180deg)}.card-face{position:absolute;inset:0;-webkit-backface-visibility:hidden;backface-visibility:hidden;border-radius:12px;box-shadow:var(--shadow-card);overflow:hidden}.card-face-inner{width:100%;height:100%;display:flex;flex-direction:column;align-items:center;justify-content:center;padding:1.5rem 2rem;position:relative;text-align:center}.card-front{background:var(--color-surface);border:1px solid var(--color-border)}.card-front:after{content:"";position:absolute;top:0;left:0;right:0;height:4px;background:var(--color-accent)}.card-back{transform:rotateY(180deg);background:var(--color-surface);border:1px solid var(--color-border);color:var(--color-text-primary)}.card-back:after{content:"";position:absolute;top:0;left:0;right:0;height:4px;background:var(--color-accent)}.face-top{position:absolute;top:.75rem;left:1.25rem;right:1.25rem;display:flex;align-items:center;gap:.5rem}.face-badge{font-size:.7rem;font-weight:700;letter-spacing:.05em;text-transform:uppercase;padding:.15rem .6rem;border-radius:4px;background:var(--color-bg);color:var(--color-text-secondary)}.back-badge{background:var(--color-bg)}.face-hint{margin-left:auto;font-size:.7rem;color:var(--color-text-secondary)}.card-back .face-hint{color:var(--color-text-secondary)}.card-question{font-size:clamp(1rem,2.8vw,1.25rem);font-weight:700;line-height:1.6;color:var(--color-text-primary);white-space:pre-line;max-height:60%;overflow-y:auto}.card-answer{font-size:clamp(1.1rem,3.2vw,1.5rem);font-weight:700;line-height:1.4;color:inherit;white-space:pre-line;margin-bottom:.5rem}.card-sub{font-size:clamp(.75rem,1.8vw,.9rem);color:inherit;opacity:.85;line-height:1.5;white-space:pre-line;max-height:30%;overflow-y:auto}.card-img{max-width:85%;max-height:35%;object-fit:contain;border-radius:8px;margin-top:.75rem;border:1px solid rgba(255,255,255,.2)}.card-watermark{position:absolute;bottom:.75rem;right:1rem;font-size:.6rem;letter-spacing:.2em;text-transform:uppercase;color:var(--color-text-secondary);opacity:.15;pointer-events:none}.card-back .card-watermark{color:inherit;opacity:.1}.mastery-row{display:flex;gap:.75rem;width:100%}.mastery-btn{flex:1;padding:.75rem .5rem;border-radius:8px;border:1px solid var(--color-border);background:var(--color-surface);cursor:pointer;display:flex;flex-direction:column;align-items:center;gap:.2rem;opacity:.3;pointer-events:none;transform:translateY(4px);transition:all .2s;min-height:64px}.mastery-btn.active{opacity:1;pointer-events:all;transform:translateY(0)}.m-icon{font-size:1.25rem;line-height:1}.m-label{font-size:.75rem;font-weight:600;color:var(--color-text-secondary)}.mastery-btn:hover{transform:translateY(-2px);box-shadow:var(--shadow-card)}.m-forgot .m-icon{color:var(--color-forgot)}.m-forgot:hover{background:var(--color-forgot-bg);border-color:var(--color-forgot)}.m-unsure .m-icon{color:var(--color-unsure)}.m-unsure:hover{background:var(--color-unsure-bg);border-color:var(--color-unsure)}.m-knew .m-icon{color:var(--color-knew)}.m-knew:hover{background:var(--color-knew-bg);border-color:var(--color-knew)}.kb-hint{font-size:.75rem;color:var(--color-text-secondary);text-align:center}.complete-overlay{position:fixed;inset:0;z-index:200;background:var(--color-bg);display:flex;align-items:center;justify-content:center;padding:1.25rem}.complete-card{background:var(--color-surface);border:1px solid var(--color-border);border-radius:12px;box-shadow:var(--shadow-overlay);padding:2.5rem 2rem;max-width:440px;width:100%;text-align:center}.complete-icon{font-size:3rem;margin-bottom:.75rem;color:var(--color-accent)}.complete-title{font-size:1.6rem;font-weight:700;margin-bottom:1.5rem}.complete-stats{display:flex;gap:.75rem;justify-content:center;margin-bottom:1.5rem}.stat-pill{padding:.75rem 1rem;border-radius:8px;border:1px solid var(--color-border);display:flex;flex-direction:column;align-items:center;gap:.2rem;min-width:80px}.sp-n{font-size:1.5rem;font-weight:700;line-height:1}.sp-l{font-size:.7rem;color:var(--color-text-secondary);font-weight:600}.stat-pill.sp-knew{background:var(--color-knew-bg);border-color:var(--color-knew);color:var(--color-knew)}.stat-pill.sp-unsure{background:var(--color-unsure-bg);border-color:var(--color-unsure);color:var(--color-unsure)}.stat-pill.sp-forgot{background:var(--color-forgot-bg);border-color:var(--color-forgot);color:var(--color-forgot)}.complete-actions{display:flex;gap:.75rem;justify-content:center;flex-wrap:wrap}.list-toggle{position:fixed;right:0;top:50%;transform:translateY(-50%);background:var(--color-accent);color:var(--color-on-accent, var(--color-accent-text));padding:1rem .5rem;border-radius:8px 0 0 8px;cursor:pointer;z-index:80;writing-mode:vertical-lr;font-size:.75rem;font-weight:700;letter-spacing:.1em;display:flex;flex-direction:column;align-items:center;gap:.5rem;box-shadow:var(--shadow-card)}.list-panel{position:fixed;right:-280px;top:0;bottom:0;width:280px;background:var(--color-surface);border-left:1px solid var(--color-border);z-index:110;transition:right .25s ease;overflow-y:auto;box-shadow:var(--shadow-overlay)}.list-panel.open{right:0}.list-head{position:sticky;top:0;padding:1rem 1.25rem;background:var(--color-surface);border-bottom:1px solid var(--color-border);display:flex;align-items:center;justify-content:space-between;font-size:.9rem;font-weight:700}.list-close{background:var(--color-bg);border:1px solid var(--color-border);border-radius:4px;padding:.25rem .75rem;font-size:.75rem;color:var(--color-text-secondary);cursor:pointer}.list-body{padding:.75rem}.list-item{padding:.6rem .75rem;border-radius:6px;cursor:pointer;font-size:.85rem;display:flex;align-items:flex-start;gap:.6rem;margin-bottom:2px;transition:background .15s}.list-item:hover{background:var(--color-bg)}.list-item.current{background:var(--color-accent-light);font-weight:600}.li-n{font-size:.7rem;color:var(--color-text-secondary);min-width:1.5rem;margin-top:2px}.li-d{width:8px;height:8px;border-radius:50%;background:var(--color-border);flex-shrink:0;margin-top:6px}.li-d.knew{background:var(--color-knew)}.li-d.unsure{background:var(--color-unsure)}.li-d.forgot{background:var(--color-forgot)}.btn-primary{background:var(--color-accent);color:var(--color-on-accent, var(--color-accent-text));border:none;border-radius:8px;padding:.75rem 1.5rem;font-size:.95rem;font-weight:700;cursor:pointer;transition:all .15s}.btn-primary:hover{opacity:.9;transform:translateY(-1px)}.btn-secondary{background:var(--color-bg);color:var(--color-text-primary);border:1px solid var(--color-border);border-radius:8px;padding:.75rem 1.25rem;font-size:.9rem;font-weight:600;cursor:pointer}.toast{position:fixed;bottom:2rem;left:50%;transform:translate(-50%);background:var(--color-text-primary);color:var(--color-bg);padding:.6rem 1.5rem;border-radius:100px;font-size:.85rem;font-weight:600;z-index:300;opacity:0;transition:opacity .2s}.toast.visible{opacity:1}@media(max-width:600px){.card-scene{aspect-ratio:3/2}.mastery-row{gap:.5rem}.mastery-btn{padding:.6rem .25rem;min-height:56px}.m-label{font-size:.65rem}.kb-hint{display:none}}