:root{--success: #10b981;--error: #ef4444;--warning: #f59e0b;--accent: #3b82f6;--accent-hover: #2563eb}[data-theme=dark]{--bg-primary: #0f172a;--bg-secondary: #1e293b;--text-primary: #f8fafc;--text-secondary: #94a3b8;--glass-bg: rgba(30, 41, 59, .7);--glass-border: rgba(255, 255, 255, .08);--card-bg: #1e293b}[data-theme=light]{--bg-primary: #f1f5f9;--bg-secondary: #ffffff;--text-primary: #0f172a;--text-secondary: #475569;--glass-bg: rgba(255, 255, 255, .8);--glass-border: rgba(0, 0, 0, .1);--card-bg: #ffffff}*{box-sizing:border-box;margin:0;padding:0}body{font-family:Inter,system-ui,-apple-system,sans-serif;background-color:var(--bg-primary);color:var(--text-primary);-webkit-font-smoothing:antialiased;min-height:100vh;transition:background-color .3s,color .3s}.app-container{display:flex;height:100vh;width:100vw;background-color:var(--bg-primary);overflow:hidden}.sidebar{width:240px;height:100vh;background:var(--bg-secondary);border-right:1px solid var(--glass-border);display:flex;flex-direction:column;padding:32px 16px;flex-shrink:0;transition:all .3s ease;z-index:100}.sidebar h1{font-size:1.25rem;font-weight:800;margin-bottom:40px;padding:0 12px;background:linear-gradient(135deg,var(--accent) 0%,#a855f7 100%);-webkit-background-clip:text;background-clip:text;-webkit-text-fill-color:transparent;letter-spacing:-.5px}.nav-links{display:flex;flex-direction:column;gap:4px}.nav-item{display:flex;align-items:center;gap:12px;padding:12px 16px;border-radius:10px;color:var(--text-secondary);text-decoration:none;font-weight:500;font-size:.95rem;transition:all .2s cubic-bezier(.4,0,.2,1)}.nav-item:hover{background:#3b82f614;color:var(--accent);transform:translate(4px)}.nav-item.active{background:linear-gradient(90deg,var(--accent) 0%,#6366f1 100%);color:#fff;box-shadow:0 8px 16px -4px #3b82f666}.main-content{flex:1;display:flex;flex-direction:column;overflow:hidden;background-color:var(--bg-primary);position:relative}.page-content{flex:1;padding:24px;overflow-y:auto}.top-header{height:70px;display:flex;align-items:center;justify-content:space-between;padding:0 24px;border-bottom:1px solid var(--glass-border);background:var(--glass-bg);-webkit-backdrop-filter:blur(8px);backdrop-filter:blur(8px);z-index:50;flex-shrink:0}.mobile-menu-btn{display:none;background:none;border:none;color:var(--text-primary);cursor:pointer;padding:8px;margin-right:12px}.glass-panel{background:var(--glass-bg);backdrop-filter:blur(12px);-webkit-backdrop-filter:blur(12px);border:1px solid var(--glass-border);border-radius:12px}@keyframes fadeIn{0%{opacity:0;transform:translateY(10px)}to{opacity:1;transform:translateY(0)}}.animate-fade-in{animation:fadeIn .4s ease-out forwards}::-webkit-scrollbar{width:8px}::-webkit-scrollbar-track{background:transparent}::-webkit-scrollbar-thumb{background:var(--bg-secondary);border-radius:4px}::-webkit-scrollbar-thumb:hover{background:var(--text-secondary)}.switch{position:relative;display:inline-block;width:44px;height:24px}.switch input{opacity:0;width:0;height:0}.slider{position:absolute;cursor:pointer;top:0;left:0;right:0;bottom:0;background-color:#ffffff1a;transition:.4s;border:1px solid var(--glass-border)}.slider:before{position:absolute;content:"";height:16px;width:16px;left:3px;bottom:3px;background-color:#fff;transition:.4s;box-shadow:0 2px 4px #0003}input:checked+.slider{background-color:var(--accent)}input:focus+.slider{box-shadow:0 0 1px var(--accent)}input:checked+.slider:before{transform:translate(20px)}.slider.round{border-radius:24px}.slider.round:before{border-radius:50%}@media(max-width:768px){.app-container{position:relative}.sidebar{position:fixed;top:0;left:0;height:100vh;transform:translate(-100%);box-shadow:4px 0 24px #00000026}.sidebar.open{transform:translate(0)}.sidebar-overlay{display:none;position:fixed;top:0;left:0;width:100vw;height:100vh;background:#00000080;-webkit-backdrop-filter:blur(4px);backdrop-filter:blur(4px);z-index:90;opacity:0;transition:opacity .3s ease}.sidebar-overlay.visible{display:block;opacity:1}.main-content{width:100vw}.top-header{padding:0 16px}.mobile-menu-btn{display:flex;align-items:center;justify-content:center}.header-title{display:flex;align-items:center}.page-content{padding:16px}.glass-panel{padding:16px!important}.words-grid,.dashboard-grid{grid-template-columns:1fr!important}.target-sentence-container{padding:20px 16px!important}.target-sentence{font-size:1.5rem!important}.interactive-sentence{font-size:1.1rem!important}h2.page-title{font-size:1.5rem}.practice-controls-mobile{flex-direction:column;gap:16px;align-items:stretch!important}.practice-controls-mobile>div,.practice-controls-mobile>button{width:100%;justify-content:center}}