*,*:before,*:after{box-sizing:border-box;margin:0;padding:0}html{-webkit-text-size-adjust:100%;text-rendering:optimizeLegibility;-webkit-font-smoothing:antialiased;-moz-osx-font-smoothing:grayscale}body{min-height:100dvh;line-height:1.5}img,svg,video{display:block;max-width:100%}input,button,textarea,select{font:inherit}button{cursor:pointer;border:none;background:none}a{color:inherit;text-decoration:none}ul,ol{list-style:none}h1,h2,h3,h4,h5,h6{font-size:inherit;font-weight:inherit}:root{--color-red: #E84057;--color-red-light: #FDEAED;--color-red-dark: #C4283B;--color-gold: #F5C518;--color-gold-light: #FEF9E7;--color-ink: #1A1A2E;--color-ink-soft: #374151;--color-muted: #6B7280;--color-border: #E5E7EB;--color-border-soft: #F3F4F6;--color-surface: #FAFAF8;--color-white: #FFFFFF;--level-1: #22C55E;--level-1-light: #DCFCE7;--level-2: #3B82F6;--level-2-light: #DBEAFE;--level-3: #F59E0B;--level-3-light: #FEF3C7;--level-4: #A855F7;--level-4-light: #F3E8FF;--level-5: #F97316;--level-5-light: #FFF7ED;--level-6: #EF4444;--level-6-light: #FEE2E2;--level-7: #EC4899;--level-7-light: #FCE7F3;--color-success: #22C55E;--color-success-light: #DCFCE7;--color-danger: #EF4444;--color-danger-light: #FEE2E2;--color-warning: #F59E0B;--color-warning-light: #FEF3C7;--space-1: .25rem;--space-2: .5rem;--space-3: .75rem;--space-4: 1rem;--space-5: 1.25rem;--space-6: 1.5rem;--space-8: 2rem;--space-10: 2.5rem;--space-12: 3rem;--space-16: 4rem;--space-20: 5rem;--space-24: 6rem;--radius-sm: .375rem;--radius-md: .625rem;--radius-lg: 1rem;--radius-xl: 1.5rem;--radius-full: 9999px;--shadow-sm: 0 1px 2px 0 rgb(0 0 0 / .05);--shadow-md: 0 4px 6px -1px rgb(0 0 0 / .07), 0 2px 4px -2px rgb(0 0 0 / .07);--shadow-lg: 0 10px 15px -3px rgb(0 0 0 / .08), 0 4px 6px -4px rgb(0 0 0 / .05);--shadow-xl: 0 20px 25px -5px rgb(0 0 0 / .08), 0 8px 10px -6px rgb(0 0 0 / .04);--shadow-card: 0 2px 8px 0 rgb(0 0 0 / .06), 0 0 0 1px rgb(0 0 0 / .04);--transition-fast: .12s ease;--transition-base: .2s 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progressFill{0%{width:0}}.progress-animate{animation:progressFill .8s cubic-bezier(.4,0,.2,1) both}@keyframes pulse{0%,to{opacity:1}50%{opacity:.6}}.pulse{animation:pulse 2s ease-in-out infinite}.navbar{position:fixed;top:0;left:0;right:0;height:64px;background:var(--color-white);border-bottom:1px solid var(--color-border);display:flex;align-items:center;z-index:var(--z-navbar);-webkit-backdrop-filter:blur(12px);backdrop-filter:blur(12px)}.navbar .container{display:flex;align-items:center;justify-content:space-between}.navbar-logo{display:flex;align-items:center;gap:var(--space-3);font-weight:700;font-size:1.125rem;color:var(--color-ink)}@media (max-width: 480px){.navbar-logo span:not(.logo-char){display:none}.navbar-logo{gap:0}}.navbar-logo .logo-char{font-family:"Noto Serif SC",serif;font-size:1.5rem;color:var(--color-red);line-height:1}.navbar-nav{display:flex;align-items:center;gap:var(--space-1)}.nav-link{padding:var(--space-2) var(--space-3);border-radius:var(--radius-md);font-size:.875rem;font-weight:500;color:var(--color-muted);transition:color var(--transition-fast),background var(--transition-fast)}.nav-link:hover{color:var(--color-ink);background:var(--color-border-soft)}.nav-link.active{color:var(--color-red);background:var(--color-red-light)}.btn{display:inline-flex;align-items:center;justify-content:center;gap:var(--space-2);padding:var(--space-3) var(--space-5);border-radius:var(--radius-md);font-weight:600;font-size:1.125rem;transition:all var(--transition-fast);white-space:nowrap;-webkit-user-select:none;user-select:none}.btn:active{transform:scale(.97)}.btn-primary{background:var(--color-red);color:#fff;box-shadow:0 2px 8px #e8405759}.btn-primary:hover{background:var(--color-red-dark);box-shadow:0 4px 12px #e8405773}.btn-secondary{background:var(--color-border-soft);color:var(--color-ink-soft);border:1px solid var(--color-border)}.btn-secondary:hover{background:var(--color-border);color:var(--color-ink)}.btn-ghost{background:transparent;color:var(--color-muted)}.btn-ghost:hover{background:var(--color-border-soft);color:var(--color-ink)}.btn-lg{padding:var(--space-4) var(--space-8);font-size:1.2rem;border-radius:var(--radius-lg)}.btn-sm{padding:var(--space-2) var(--space-4);font-size:.975rem;border-radius:var(--radius-sm)}.btn-icon{width:40px;height:40px;padding:0;border-radius:var(--radius-md)}.level-chip{display:inline-flex;align-items:center;padding:2px 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var(--space-4);display:flex;flex-direction:column;align-items:center;gap:var(--space-6)}.card-scene{width:100%;max-width:560px;height:460px}.card-inner{border-radius:var(--radius-xl);cursor:pointer}.card-face{display:flex;flex-direction:column;align-items:center;justify-content:center;padding:var(--space-10);background:var(--color-white);border-radius:var(--radius-xl);box-shadow:var(--shadow-xl);border:1px solid var(--color-border);gap:var(--space-4);overflow:hidden}.card-face.back{justify-content:flex-start;padding:var(--space-8);overflow-y:auto;scrollbar-width:thin;scrollbar-color:var(--color-border) transparent}.card-face.back::-webkit-scrollbar{width:4px}.card-face.back::-webkit-scrollbar-thumb{background:var(--color-border);border-radius:2px}.card-face.back::-webkit-scrollbar-track{background:transparent}.card-hint{position:absolute;bottom:var(--space-4);font-size:.75rem;color:var(--color-border);font-weight:500;letter-spacing:.05em;text-transform:uppercase}.rating-buttons{display:grid;grid-template-columns:repeat(4,1fr);gap:var(--space-3);width:100%;max-width:560px}.rating-btn{display:flex;flex-direction:column;align-items:center;padding:var(--space-3) var(--space-2);border-radius:var(--radius-md);font-weight:600;font-size:.875rem;transition:all var(--transition-fast);border:2px solid transparent;gap:2px}.rating-btn .rating-label{font-size:.75rem;font-weight:500;color:inherit;opacity:.8}.rating-btn.again{background:#fee2e2;color:#991b1b}.rating-btn.hard{background:#fef3c7;color:#92400e}.rating-btn.good{background:#dcfce7;color:#166534}.rating-btn.easy{background:#dbeafe;color:#1e40af}.rating-btn:hover{transform:translateY(-2px);box-shadow:var(--shadow-md)}.rating-btn:active{transform:scale(.96)}.progress-bar{height:6px;background:var(--color-border);border-radius:var(--radius-full);overflow:hidden}.progress-bar-fill{height:100%;border-radius:var(--radius-full);transition:width .4s ease}.session-header{padding:var(--space-4) var(--space-6);display:flex;align-items:center;gap:var(--space-4);border-bottom:1px solid var(--color-border);background:var(--color-white);position:sticky;top:64px;z-index:10}.levels-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(240px,1fr));gap:var(--space-5)}.level-card{background:var(--color-white);border-radius:var(--radius-xl);padding:var(--space-6);box-shadow:var(--shadow-card);border:1px solid var(--color-border);transition:transform var(--transition-base),box-shadow var(--transition-base);cursor:pointer;position:relative;overflow:hidden}.level-card:hover{transform:translateY(-3px);box-shadow:var(--shadow-lg)}.level-card:before{content:"";position:absolute;top:0;left:0;right:0;height:4px;border-radius:var(--radius-xl) var(--radius-xl) 0 0}.level-card[data-level="1"]:before{background:var(--level-1)}.level-card[data-level="2"]:before{background:var(--level-2)}.level-card[data-level="3"]:before{background:var(--level-3)}.level-card[data-level="4"]:before{background:var(--level-4)}.level-card[data-level="5"]:before{background:var(--level-5)}.level-card[data-level="6"]:before{background:var(--level-6)}.level-card[data-level="7"]:before{background:var(--level-7)}.level-card-header{display:flex;align-items:center;justify-content:space-between;margin-bottom:var(--space-4)}.level-card-char{font-family:"Noto Serif SC",serif;font-size:2.5rem;font-weight:700;line-height:1}.level-card[data-level="1"] .level-card-char{color:var(--level-1)}.level-card[data-level="2"] .level-card-char{color:var(--level-2)}.level-card[data-level="3"] .level-card-char{color:var(--level-3)}.level-card[data-level="4"] .level-card-char{color:var(--level-4)}.level-card[data-level="5"] .level-card-char{color:var(--level-5)}.level-card[data-level="6"] .level-card-char{color:var(--level-6)}.level-card[data-level="7"] .level-card-char{color:var(--level-7)}.level-card-meta{font-size:.8125rem;color:var(--color-muted);margin-top:var(--space-1)}.streak-banner{background:linear-gradient(135deg,#fef9e7,#fff7ed);border:1px solid #FDE68A;border-radius:var(--radius-xl);padding:var(--space-5) var(--space-6);display:flex;align-items:center;gap:var(--space-4);margin-bottom:var(--space-8)}.streak-flame{font-size:2.5rem;line-height:1}.streak-text h2{font-size:1.25rem;font-weight:700;color:var(--color-ink)}.streak-text p{font-size:.875rem;color:var(--color-muted);margin-top:2px}.quiz-options{display:grid;grid-template-columns:1fr 1fr;gap:var(--space-4);width:100%;max-width:560px}.quiz-option{padding:var(--space-5);border-radius:var(--radius-lg);border:2px solid var(--color-border);background:var(--color-white);text-align:center;font-weight:500;font-size:1rem;transition:all var(--transition-fast);cursor:pointer;position:relative}.quiz-option:hover:not(:disabled){border-color:var(--color-red);background:var(--color-red-light)}.quiz-option.correct{border-color:var(--color-success);background:var(--color-success-light);color:#166534}.quiz-option.wrong{border-color:var(--color-danger);background:var(--color-danger-light);color:#991b1b}.quiz-option .option-key{position:absolute;top:var(--space-2);left:var(--space-2);width:20px;height:20px;border-radius:var(--radius-sm);background:var(--color-border-soft);font-size:.6875rem;font-weight:700;color:var(--color-muted);display:flex;align-items:center;justify-content:center}#toast-container{position:fixed;bottom:var(--space-6);right:var(--space-6);display:flex;flex-direction:column;gap:var(--space-3);z-index:var(--z-toast);pointer-events:none}.toast{padding:var(--space-3) var(--space-5);border-radius:var(--radius-lg);font-weight:500;font-size:.875rem;box-shadow:var(--shadow-lg);animation:slideUp .25s ease both;pointer-events:all;display:flex;align-items:center;gap:var(--space-2);max-width:320px}.toast.success{background:#166534;color:#fff}.toast.error{background:#991b1b;color:#fff}.toast.info{background:var(--color-ink);color:#fff}.empty-state{display:flex;flex-direction:column;align-items:center;justify-content:center;padding:var(--space-20) var(--space-6);text-align:center;gap:var(--space-4)}.empty-state .emoji{font-size:4rem;line-height:1}.session-summary{display:flex;flex-direction:column;align-items:center;gap:var(--space-6);padding:var(--space-12) var(--space-6);text-align:center;max-width:480px;margin:0 auto}.summary-stat{display:flex;flex-direction:column;align-items:center;gap:var(--space-1)}.summary-stat .value{font-size:2.5rem;font-weight:700;color:var(--color-ink);line-height:1}.summary-stats-row{display:flex;gap:var(--space-8);justify-content:center}.due-badge{display:inline-flex;align-items:center;padding:2px 8px;border-radius:var(--radius-full);font-size:.75rem;font-weight:700;background:var(--color-red);color:#fff;line-height:1.4}.example-block{background:var(--color-border-soft);border-radius:var(--radius-md);padding:var(--space-4);width:100%;display:flex;flex-direction:column;gap:var(--space-1);font-size:1.05rem}.pos-tag{display:inline-flex;align-items:center;padding:1px 8px;border-radius:var(--radius-full);font-size:.825rem;font-weight:600;text-transform:uppercase;letter-spacing:.04em;background:var(--color-border-soft);color:var(--color-muted)}