:root{color-scheme:dark;--bg: #0a0a0f;--surface: #12121a;--surface2: #1a1a26;--border: rgba(255, 255, 255, .08);--border-hover: rgba(255, 255, 255, .15);--text: #e8e8f0;--text-dim: rgba(255, 255, 255, .5);--accent: #6366f1;--accent-glow: rgba(99, 102, 241, .15);--green: #22c55e;--green-glow: rgba(34, 197, 94, .15);--red: #ef4444;--red-glow: rgba(239, 68, 68, .15);--yellow: #eab308;--radius: 12px;--radius-sm: 8px;font-family:Inter,ui-sans-serif,system-ui,-apple-system,Segoe UI,Roboto,sans-serif;line-height:1.6}*{box-sizing:border-box;margin:0}html,body,#root{min-height:100vh;background:var(--bg);color:var(--text)}.app{min-height:100vh;display:flex;flex-direction:column}.header{display:flex;align-items:center;justify-content:space-between;padding:1rem 2rem;border-bottom:1px solid var(--border);background:var(--surface);position:sticky;top:0;z-index:100;-webkit-backdrop-filter:blur(12px);backdrop-filter:blur(12px);flex-wrap:wrap;gap:.75rem}.logo{font-size:1.25rem;font-weight:700;letter-spacing:-.03em;background:linear-gradient(135deg,var(--accent),#a78bfa);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}.nav-pills{display:flex;gap:.5rem;align-items:center;flex-wrap:wrap}.pill{padding:.4rem 1rem;border-radius:100px;border:1px solid var(--border);background:transparent;color:var(--text-dim);font-size:.8rem;font-weight:500;cursor:pointer;transition:all .2s;white-space:nowrap}.pill:hover{border-color:var(--border-hover);color:var(--text)}.pill.active{background:var(--accent);border-color:var(--accent);color:#fff}.pill.score-display{cursor:default;color:var(--text)}.timer-pill{color:var(--yellow);border-color:#eab3084d;font-variant-numeric:tabular-nums}.timer-pill.urgent{color:var(--red);border-color:var(--red);animation:pulse .5s infinite alternate}@keyframes pulse{to{opacity:.6}}.main{flex:1;display:flex;justify-content:center;padding:2rem 1.5rem}.input-card{max-width:640px;width:100%;display:flex;flex-direction:column;gap:1rem}.input-card h2{font-size:1.5rem;font-weight:700;letter-spacing:-.02em}.hint{color:var(--text-dim);font-size:.85rem}.quiz-title-input{width:100%;padding:.75rem 1rem;background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-sm);color:var(--text);font-size:.9rem;outline:none;transition:border-color .2s}.quiz-title-input:focus{border-color:var(--accent)}.notes-input{width:100%;padding:1rem;background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);color:var(--text);font-size:.9rem;font-family:inherit;resize:vertical;outline:none;transition:border-color .2s;line-height:1.7}.notes-input:focus{border-color:var(--accent);box-shadow:0 0 0 3px var(--accent-glow)}.notes-input::placeholder{color:var(--text-dim)}.timer-toggle{display:flex;flex-direction:column;gap:.5rem}.toggle-label{display:flex;align-items:center;gap:.75rem;cursor:pointer;font-size:.9rem;color:var(--text-dim)}.toggle-label input{display:none}.toggle-switch{width:40px;height:22px;background:var(--surface2);border:1px solid var(--border);border-radius:100px;position:relative;transition:all .2s}.toggle-switch:after{content:"";width:16px;height:16px;background:var(--text-dim);border-radius:50%;position:absolute;top:2px;left:2px;transition:all .2s}.toggle-label input:checked+.toggle-switch{background:var(--accent);border-color:var(--accent)}.toggle-label input:checked+.toggle-switch:after{left:20px;background:#fff}.timer-config{padding-left:3.5rem}.timer-config label{display:flex;align-items:center;gap:.5rem;font-size:.85rem;color:var(--text-dim)}.timer-input{width:60px;padding:.3rem .5rem;background:var(--surface);border:1px solid 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.2s}.btn-nav:hover:not(:disabled){border-color:var(--border-hover);color:var(--text)}.btn-nav:disabled{opacity:.3;cursor:not-allowed}.btn-danger{padding:.75rem 2rem;background:transparent;border:1px solid rgba(239,68,68,.3);border-radius:var(--radius-sm);color:var(--red);font-size:.85rem;cursor:pointer;transition:all .2s;margin-top:1rem}.btn-danger:hover{background:var(--red-glow);border-color:var(--red)}.quiz-card{max-width:700px;width:100%;background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:2rem;display:flex;flex-direction:column;gap:1.5rem}.progress-bar{height:4px;background:var(--surface2);border-radius:100px;overflow:hidden}.progress-fill{height:100%;background:linear-gradient(90deg,var(--accent),#a78bfa);border-radius:100px;transition:width .3s 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.option-letter{background:var(--red);border-color:var(--red);color:#fff}.tf-label{color:var(--text-dim);font-size:.9rem}.tf-buttons{display:flex;gap:1rem}.tf-btn{flex:1;padding:1rem;background:var(--surface2);border:1px solid var(--border);border-radius:var(--radius-sm);color:var(--text);font-size:1rem;font-weight:600;cursor:pointer;transition:all .2s}.tf-btn:hover:not(:disabled){border-color:var(--accent)}.tf-btn.selected{border-color:var(--accent);background:var(--accent-glow)}.tf-btn.correct{border-color:var(--green);background:var(--green-glow);color:var(--green)}.tf-btn.wrong{border-color:var(--red);background:var(--red-glow);color:var(--red)}.tf-btn:disabled{cursor:default}.feedback-banner{display:flex;align-items:center;gap:.75rem;padding:1rem 1.25rem;border-radius:var(--radius-sm);font-size:.9rem;font-weight:500;background:var(--surface2);border:1px solid var(--border)}.feedback-icon{width:28px;height:28px;display:flex;align-items:center;justify-content:center;border-radius:50%;font-size:.85rem;font-weight:700}.quiz-nav{display:flex;justify-content:space-between;align-items:center;padding-top:.5rem}.result-card{max-width:640px;width:100%;display:flex;flex-direction:column;align-items:center;gap:1.5rem}.result-card h2{font-size:1.75rem;font-weight:700}.score-ring{width:160px;height:160px;border-radius:50%;background:conic-gradient(var(--accent) 0% var(--pct, 0%),var(--surface2) var(--pct, 0%) 100%);display:flex;flex-direction:column;align-items:center;justify-content:center;position:relative}.score-ring:before{content:"";position:absolute;top:8px;right:8px;bottom:8px;left:8px;border-radius:50%;background:var(--bg)}.score-num,.score-pct{position:relative;z-index:1}.score-num{font-size:2rem;font-weight:700}.score-pct{font-size:.85rem;color:var(--text-dim)}.result-msg{color:var(--text-dim);font-size:1rem;text-align:center}.result-breakdown{width:100%;display:flex;flex-direction:column;gap:.5rem;max-height:300px;overflow-y:auto}.breakdown-item{display:flex;align-items:flex-start;gap:.75rem;padding:.6rem .75rem;border-radius:var(--radius-sm);font-size:.85rem}.breakdown-item.correct{background:var(--green-glow)}.breakdown-item.wrong{background:var(--red-glow)}.breakdown-icon{flex-shrink:0;font-weight:700}.breakdown-item.correct .breakdown-icon{color:var(--green)}.breakdown-item.wrong .breakdown-icon{color:var(--red)}.breakdown-text{color:var(--text-dim);line-height:1.4}.result-actions{display:flex;gap:1rem;flex-wrap:wrap;justify-content:center}.flashcard-container{max-width:500px;width:100%;display:flex;flex-direction:column;align-items:center;gap:2rem}.flashcard{width:100%;aspect-ratio:3 / 2;perspective:1000px;cursor:pointer}.flashcard-inner{width:100%;height:100%;position:relative;transition:transform .6s cubic-bezier(.4,0,.2,1);transform-style:preserve-3d}.flashcard.flipped .flashcard-inner{transform:rotateY(180deg)}.flashcard-front,.flashcard-back{position:absolute;top:0;right:0;bottom:0;left:0;backface-visibility:hidden;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:1rem;padding:2rem;border-radius:var(--radius);border:1px solid var(--border);text-align:center}.flashcard-front{background:linear-gradient(135deg,var(--surface),var(--surface2))}.flashcard-back{background:linear-gradient(135deg,var(--accent-glow),var(--surface));border-color:#6366f133;transform:rotateY(180deg)}.flashcard-front h2,.flashcard-back h2{font-size:1.5rem;font-weight:600;line-height:1.4}.flash-label{font-size:.7rem;text-transform:uppercase;letter-spacing:.15em;color:var(--text-dim)}.flash-hint{font-size:.75rem;color:var(--text-dim);opacity:.6}.flash-nav{display:flex;gap:.75rem;align-items:center}.stats-grid{max-width:700px;width:100%;display:grid;grid-template-columns:repeat(3,1fr);gap:1rem}.stat-card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:1.5rem;display:flex;flex-direction:column;align-items:center;gap:.25rem}.stat-value{font-size:2rem;font-weight:700;letter-spacing:-.02em;background:linear-gradient(135deg,var(--accent),#a78bfa);-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}.stat-label{font-size:.75rem;color:var(--text-dim);text-transform:uppercase;letter-spacing:.08em}.history-section{max-width:700px;width:100%;margin-top:2rem}.history-section h2{font-size:1.1rem;margin-bottom:1rem}.history-list{display:flex;flex-direction:column;gap:.5rem}.history-item{display:flex;justify-content:space-between;align-items:center;padding:1rem 1.25rem;background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-sm);cursor:pointer;transition:all .2s}.history-item:hover{border-color:var(--border-hover);background:var(--surface2)}.history-info{display:flex;flex-direction:column;gap:.15rem}.history-title{font-weight:500;font-size:.9rem}.history-date{font-size:.75rem;color:var(--text-dim)}.history-score{display:flex;flex-direction:column;align-items:flex-end;gap:.15rem}.history-pct{font-size:1.1rem;font-weight:700}.history-pct.good{color:var(--green)}.history-pct.ok{color:var(--yellow)}.history-pct.low{color:var(--red)}.history-detail{font-size:.75rem;color:var(--text-dim)}@media(max-width:640px){.header{padding:.75rem 1rem}.main{padding:1.25rem 1rem}.quiz-card{padding:1.5rem 1rem}.stats-grid{grid-template-columns:repeat(2,1fr)}.stat-card{padding:1rem}.stat-value{font-size:1.5rem}.tf-buttons{flex-direction:column}.flashcard-front h2,.flashcard-back h2{font-size:1.15rem}.question-text{font-size:1.1rem}}