:root{--bg-primary: #0d1117;--bg-secondary: #161b22;--bg-card: #21262d;--bg-card-hover: #30363d;--accent-primary: #58a6ff;--accent-secondary: #7ee787;--text-primary: #e6edf3;--text-secondary: #8b949e;--text-muted: #484f58;--border-color: #30363d;--success: #7ee787;--error: #f85149;--shadow-glow: 0 0 20px rgba(88, 166, 255, .3);--shadow-glow-cyan: 0 0 20px rgba(126, 231, 135, .25);--transition-fast: .15s ease;--transition-normal: .25s ease}*{margin:0;padding:0;box-sizing:border-box}html{font-size:16px}body{font-family:Segoe UI,Noto Sans JP,-apple-system,BlinkMacSystemFont,sans-serif;background-color:var(--bg-primary);color:var(--text-primary);min-height:100vh;line-height:1.6}#root{min-height:100vh;display:flex;flex-direction:column}a{color:var(--accent-secondary);text-decoration:none;transition:color var(--transition-fast);line-height:normal}a:hover{color:var(--accent-primary)}button{font-family:inherit;cursor:pointer;border:none;outline:none}input{font-family:inherit;outline:none}.layout{min-height:100vh;display:flex;flex-direction:column}.header{background:var(--bg-secondary);border-bottom:1px solid var(--border-color);padding:1rem 2rem;position:sticky;top:0;z-index:100}.header-content{max-width:1200px;margin:0 auto;display:flex;justify-content:space-between;align-items:center}.logo{font-size:1.5rem;font-weight:700;color:var(--text-primary);display:flex;align-items:center;gap:.5rem}.logo-accent{color:var(--accent-primary)}.main-content{flex:1;padding:2rem;max-width:1200px;margin:0 auto;width:100%}.nav{display:flex;gap:.5rem}.nav-link{padding:.5rem 1rem;border-radius:8px;color:var(--text-secondary);font-weight:500;transition:all var(--transition-fast)}.nav-link:hover{color:var(--text-primary);background:var(--bg-card)}.nav-link.active{color:var(--accent-primary);background:#58a6ff1a}.nav-dropdown{position:relative}.dropdown-trigger{display:flex;align-items:center;gap:.35rem;padding:.5rem 1rem;border-radius:8px;border:none;background:transparent;color:var(--text-secondary);font-weight:500;font-size:inherit;cursor:pointer;transition:all var(--transition-fast)}.dropdown-trigger:hover{color:var(--text-primary);background:var(--bg-card)}.dropdown-trigger.active{color:var(--accent-primary);background:#58a6ff1a}.dropdown-arrow{font-size:.7rem;transition:transform .2s ease}.dropdown-arrow.open{transform:rotate(180deg)}.dropdown-menu{position:absolute;top:calc(100% + .5rem);right:0;min-width:180px;background:var(--bg-secondary);border:1px solid var(--border-color);border-radius:10px;padding:.5rem;box-shadow:0 10px 40px #0000004d;z-index:200;animation:dropdownFade .15s ease}@keyframes dropdownFade{0%{opacity:0;transform:translateY(-5px)}to{opacity:1;transform:translateY(0)}}.dropdown-item{display:block;padding:.6rem 1rem;border-radius:6px;color:var(--text-secondary);font-size:.9rem;transition:all .15s ease;white-space:nowrap}.dropdown-item:hover{background:var(--bg-card);color:var(--text-primary)}.language-switcher{position:relative;margin-left:.5rem}.lang-trigger{display:flex;align-items:center;gap:.35rem;padding:.5rem 1rem;border-radius:8px;background:transparent;border:none;color:var(--text-secondary);font-size:inherit;font-weight:500;cursor:pointer;transition:all var(--transition-fast)}.lang-trigger:hover{background:var(--bg-card);color:var(--text-primary)}.lang-trigger .lang-flag{font-size:inherit}.lang-trigger .dropdown-arrow{font-size:.7rem;color:var(--text-muted);transition:transform .2s ease}.lang-trigger .dropdown-arrow.open{transform:rotate(180deg)}.lang-dropdown{position:absolute;top:calc(100% + .5rem);right:0;min-width:180px;background:var(--bg-secondary);border:1px solid var(--border-color);border-radius:10px;padding:.5rem;box-shadow:0 10px 40px #0000004d;z-index:200;animation:dropdownFade .15s ease}.lang-option{display:flex;align-items:center;gap:.6rem;width:100%;padding:.55rem .8rem;border-radius:6px;background:transparent;border:none;color:var(--text-secondary);font-size:.875rem;cursor:pointer;transition:all .15s ease;text-align:left}.lang-option:hover{background:var(--bg-card);color:var(--text-primary)}.lang-option.active{background:#58a6ff1a;color:var(--accent-primary)}.lang-option .lang-flag{font-size:.75rem;font-weight:700;background:var(--bg-card);padding:.15rem .4rem;border-radius:4px;letter-spacing:.03em;min-width:28px;text-align:center;color:var(--text-secondary)}.lang-option.active .lang-flag{background:#58a6ff26;color:var(--accent-primary)}.lang-option .lang-label{font-weight:500}.tab-navigation{display:flex;gap:.5rem;margin-bottom:2rem;justify-content:center}.tab-button{padding:.75rem 2rem;background:var(--bg-card);color:var(--text-secondary);border-radius:8px;font-size:1rem;font-weight:500;transition:all var(--transition-fast)}.tab-button:hover{background:var(--bg-card-hover);color:var(--text-primary)}.tab-button.active{background:var(--accent-primary);color:var(--text-primary);box-shadow:var(--shadow-glow)}.character-grid-container{display:flex;flex-direction:column;gap:1.5rem}.row-group{display:flex;flex-direction:column;gap:.5rem}.row-label{color:var(--text-secondary);font-size:.875rem;padding-left:.5rem;font-weight:500}.character-row{display:flex;gap:.5rem;flex-wrap:wrap;justify-content:center}.character-card{width:70px;height:80px;background:var(--bg-card);border-radius:10px;display:flex;flex-direction:column;align-items:center;justify-content:center;cursor:pointer;transition:all var(--transition-normal);border:1px solid 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pulse{0%,to{transform:scale(1)}50%{transform:scale(1.05)}}.practice-card.correct{border:2px solid var(--success);box-shadow:0 0 30px #4ade8033}.practice-card.incorrect{border:2px solid var(--error);box-shadow:0 0 30px #f8717133;animation:shake .4s ease-in-out}@keyframes shake{0%,to{transform:translate(0)}20%,60%{transform:translate(-5px)}40%,80%{transform:translate(5px)}}.next-button{padding:.75rem 2rem;background:var(--accent-secondary);color:var(--bg-primary);border-radius:8px;font-size:1rem;font-weight:600;transition:all 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auto;text-align:center}.flashcard-header{margin-bottom:1.5rem}.flashcard-title{font-size:1.5rem;margin-bottom:1rem}.flashcard-toggles{display:flex;justify-content:center}.flashcard-progress{margin-bottom:2rem}.progress-bar{height:8px;background:var(--bg-card);border-radius:4px;overflow:hidden;margin-bottom:.5rem}.progress-fill{height:100%;background:linear-gradient(90deg,var(--accent-primary),var(--accent-secondary));border-radius:4px;transition:width .3s ease}.progress-text{font-size:.875rem;color:var(--text-secondary)}.flashcard-wrapper{perspective:1000px;margin-bottom:2rem;cursor:pointer}.flashcard{width:100%;height:280px;position:relative;transform-style:preserve-3d;transition:transform .6s ease}.flashcard.flipped{transform:rotateY(180deg)}.flashcard-front,.flashcard-back{position:absolute;width:100%;height:100%;backface-visibility:hidden;display:flex;flex-direction:column;align-items:center;justify-content:center;background:var(--bg-secondary);border-radius:20px;border:2px solid 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0;position:relative}.page-header:after{content:"";position:absolute;bottom:0;left:50%;transform:translate(-50%);width:100px;height:3px;background:linear-gradient(90deg,var(--accent-primary),var(--accent-secondary));border-radius:2px}.page-title{font-size:3rem;font-weight:700;background:linear-gradient(135deg,var(--text-primary),var(--accent-secondary));-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text;margin-bottom:.25rem}.page-title-japanese{font-size:1.5rem;color:var(--accent-primary);margin-bottom:.5rem;letter-spacing:.2em}.page-subtitle{color:var(--text-secondary);font-size:1rem}.grid-section{background:var(--bg-secondary);border-radius:20px;padding:2rem;margin-bottom:2rem;border:1px solid var(--border-color)}.grid-section.dakuten{background:linear-gradient(135deg,var(--bg-secondary),rgba(88,166,255,.05));border-color:#58a6ff33}.section-title{font-size:1.25rem;color:var(--text-secondary);margin-bottom:1.5rem;padding-bottom:.75rem;border-bottom:1px solid var(--border-color);display:flex;align-items:center;gap:.5rem}.section-title:before{content:"";width:4px;height:1.25rem;background:var(--accent-secondary);border-radius:2px}.grid-section.dakuten .section-title:before{background:var(--accent-primary)}.section-content{display:flex;flex-direction:column;gap:1.25rem}.character-card{width:75px;height:90px;background:linear-gradient(145deg,var(--bg-card),rgba(22,33,62,.9));border-radius:12px;display:flex;flex-direction:column;align-items:center;justify-content:center;cursor:pointer;transition:all .3s cubic-bezier(.4,0,.2,1);border:1px solid rgba(255,255,255,.05);position:relative;overflow:hidden;animation:cardEnter .5s ease-out backwards}@keyframes cardEnter{0%{opacity:0;transform:scale(.8) translateY(10px)}to{opacity:1;transform:scale(1) translateY(0)}}.character-card .card-inner{display:flex;flex-direction:column;align-items:center;justify-content:center;z-index:1}.character-card .card-shine{position:absolute;top:-50%;left:-50%;width:200%;height:200%;background:linear-gradient(45deg,transparent 40%,rgba(255,255,255,.03) 50%,transparent 60%);transform:rotate(45deg);transition:transform .6s;pointer-events:none}.character-card:hover .card-shine{transform:rotate(45deg) translate(50%,50%)}.character-card:hover{background:linear-gradient(145deg,var(--bg-card-hover),rgba(31,43,71,.95));border-color:var(--accent-secondary);transform:translateY(-4px) scale(1.02);box-shadow:0 10px 30px #0000004d,0 0 20px #7ee78733}.character-card.pressed{transform:scale(.95)}.character-card.selected{border-color:var(--accent-primary);box-shadow:0 0 25px #58a6ff66}.character-japanese{font-size:2.25rem;font-weight:400;color:var(--text-primary);line-height:1;transition:transform .2s,color .2s}.character-card:hover .character-japanese{color:var(--accent-secondary);transform:scale(1.1)}.character-romaji{font-size:.8rem;color:var(--text-muted);margin-top:.35rem;opacity:0;transform:translateY(5px);transition:all .2s ease}.character-card:hover .character-romaji,.character-card.show-romaji .character-romaji{opacity:1;transform:translateY(0);color:var(--text-secondary)}.row-group{display:flex;flex-direction:column;gap:.75rem}.row-label{color:var(--accent-secondary);font-size:.9rem;padding-left:.5rem;font-weight:600;letter-spacing:.05em}.character-row{display:flex;gap:.6rem;flex-wrap:wrap;justify-content:center}.converter-container{max-width:600px;margin:0 auto 3rem;padding:2rem;background:linear-gradient(145deg,var(--bg-secondary),rgba(26,26,46,.8));border-radius:20px;border:1px solid var(--border-color);position:relative;overflow:hidden}.converter-container:before{content:"";position:absolute;top:0;left:0;right:0;height:3px;background:linear-gradient(90deg,var(--accent-primary),var(--accent-secondary))}.converter-header{display:flex;justify-content:space-between;align-items:center;margin-bottom:1.5rem;flex-wrap:wrap;gap:1rem}.converter-title{font-size:1.25rem;color:var(--text-primary);font-weight:600}.converter-toggle{flex-shrink:0}.toggle-button.with-label{display:flex;flex-direction:column;align-items:center;gap:.15rem;padding:.5rem 1.25rem}.toggle-jp{font-size:1rem;font-weight:500}.toggle-romaji{font-size:.7rem;opacity:.7}.converter-input-wrapper{position:relative;margin-bottom:1rem}.converter-input{width:100%;padding:1rem 1.5rem;font-size:1.25rem;background:var(--bg-card);border:2px solid var(--border-color);border-radius:12px;color:var(--text-primary);transition:all .3s ease}.converter-input:focus{border-color:var(--accent-secondary);box-shadow:0 0 20px #7ee78726}.converter-input::placeholder{color:var(--text-muted)}.input-glow{position:absolute;bottom:0;left:50%;transform:translate(-50%);width:0;height:2px;background:var(--accent-secondary);transition:width .3s ease;border-radius:2px}.converter-input:focus+.input-glow{width:80%}.converter-output-wrapper{position:relative;margin-bottom:1rem}.converter-output{min-height:80px;padding:1.5rem;background:var(--bg-primary);border-radius:12px;font-size:2rem;color:var(--accent-secondary);text-align:center;display:flex;align-items:center;justify-content:center;border:1px solid var(--border-color);word-break:break-all;line-height:1.4}.converter-placeholder{color:var(--text-muted);opacity:.5}.copy-btn{position:absolute;top:.75rem;right:.75rem;padding:.5rem;background:var(--bg-card);border-radius:8px;color:var(--text-secondary);transition:all .2s ease}.copy-btn:hover{background:var(--bg-card-hover);color:var(--accent-secondary)}.converter-hints{display:flex;gap:1rem;justify-content:center;flex-wrap:wrap}.hint{font-size:.8rem;color:var(--text-muted);background:var(--bg-card);padding:.25rem .75rem;border-radius:20px}@media(max-width:768px){.page-title{font-size:2rem}.page-title-japanese{font-size:1.25rem}.grid-section{padding:1.25rem;border-radius:16px}.character-card{width:60px;height:72px}.character-japanese{font-size:1.75rem}.converter-container{padding:1.5rem;margin-bottom:2rem}.converter-header{flex-direction:column;align-items:stretch}.converter-title{text-align:center}.converter-toggle{justify-content:center}.converter-output{font-size:1.5rem;min-height:60px}.flashcard{height:220px}.flashcard-character{font-size:5rem}.flashcard-romaji{font-size:2rem}.flashcard-actions{flex-direction:column}.flashcard-btn{width:100%}}.learn-container{max-width:900px;margin:0 auto;animation:pageEnter .5s ease-out}.learn-tabs{display:flex;gap:.5rem;margin-bottom:2rem;flex-wrap:wrap;justify-content:center}.learn-tab{display:flex;align-items:center;gap:.5rem;padding:.75rem 1.25rem;background:var(--bg-card);border-radius:10px;color:var(--text-secondary);font-size:.95rem;font-weight:500;transition:all .2s ease;border:1px solid transparent}.learn-tab:hover{background:var(--bg-card-hover);color:var(--text-primary)}.learn-tab.active{background:linear-gradient(135deg,var(--accent-primary),#79c0ff);color:#fff;border-color:transparent;box-shadow:0 4px 15px #58a6ff4d}.tab-icon{font-size:1.1rem}.learn-content{animation:fadeIn .3s ease}.learn-section{background:var(--bg-secondary);border-radius:20px;padding:2rem;border:1px solid var(--border-color)}.section-header{display:flex;align-items:baseline;gap:1rem;margin-bottom:1rem;flex-wrap:wrap}.section-header h2{font-size:1.5rem;color:var(--text-primary)}.title-jp{font-size:1.1rem;color:var(--accent-secondary)}.section-description{color:var(--text-secondary);line-height:1.7;margin-bottom:2rem}.structure-visual{margin:2rem 0}.structure-comparison{display:flex;align-items:center;justify-content:center;gap:1.5rem;flex-wrap:wrap}.lang-block{background:var(--bg-card);border-radius:12px;padding:1.5rem;text-align:center;min-width:250px;border:1px solid var(--border-color)}.lang-block h4{color:var(--text-secondary);font-size:.9rem;margin-bottom:1rem;text-transform:uppercase;letter-spacing:.05em}.lang-block.japanese{border-color:var(--accent-secondary);box-shadow:0 0 20px #7ee7871a}.lang-block.japanese h4{color:var(--accent-secondary)}.word-order{display:flex;gap:.5rem;justify-content:center;flex-wrap:wrap}.word{padding:.5rem 1rem;border-radius:8px;font-weight:500}.word.subject{background:#4ade8033;color:var(--success)}.word.verb{background:#58a6ff33;color:var(--accent-primary)}.word.object{background:#7ee78733;color:var(--accent-secondary)}.arrow{font-size:1.5rem;color:var(--text-muted)}.key-points{background:var(--bg-card);border-radius:12px;padding:1.5rem;margin-bottom:2rem}.key-points h3{color:var(--text-primary);margin-bottom:1rem;font-size:1.1rem}.key-points ul{list-style:none}.key-points li{padding:.5rem 0 .5rem 1.5rem;position:relative;color:var(--text-secondary)}.key-points li:before{content:"✓";position:absolute;left:0;color:var(--success)}.examples-section h3{color:var(--text-primary);margin-bottom:1rem;font-size:1.1rem}.example-card{background:var(--bg-card);border-radius:12px;padding:1.25rem;margin-bottom:1rem;border-left:3px solid var(--accent-secondary)}.example-card.structure-example{text-align:center}.example-japanese{font-size:1.5rem;color:var(--text-primary);margin-bottom:.5rem}.example-romaji{color:var(--accent-secondary);font-size:.95rem;margin-bottom:.5rem}.example-english{color:var(--text-secondary);font-style:italic}.example-breakdown{margin-top:.75rem;padding-top:.75rem;border-top:1px solid var(--border-color);font-family:monospace;font-size:.85rem;color:var(--text-muted)}.particles-grid{display:grid;gap:1rem}.particle-card{background:var(--bg-card);border-radius:12px;overflow:hidden;cursor:pointer;transition:all .2s ease;border:1px solid var(--border-color)}.particle-card:hover{border-color:var(--accent-secondary)}.particle-card.expanded{border-color:var(--accent-primary);box-shadow:0 0 20px #58a6ff26}.particle-header{display:flex;justify-content:space-between;align-items:center;padding:1rem 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ease}.grammar-description{color:var(--text-secondary);line-height:1.6;margin-bottom:1rem}.grammar-points{background:var(--bg-secondary);border-radius:8px;padding:1rem;margin-bottom:1rem}.grammar-points ul{list-style:none}.grammar-points li{padding:.4rem 0 .4rem 1.25rem;position:relative;color:var(--text-secondary);font-size:.95rem}.grammar-points li:before{content:"•";position:absolute;left:0;color:var(--accent-secondary)}.grammar-examples{display:flex;flex-direction:column;gap:.5rem}.phrase-category{margin-bottom:2rem}.phrase-category:last-child{margin-bottom:0}.category-title{font-size:1.1rem;color:var(--accent-secondary);margin-bottom:1rem;padding-bottom:.5rem;border-bottom:1px solid var(--border-color)}.phrases-list{display:grid;gap:.75rem;grid-template-columns:repeat(auto-fill,minmax(280px,1fr))}.phrase-card{background:var(--bg-card);border-radius:10px;padding:1rem;transition:all .2s ease;border:1px solid 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