@import "https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&family=Fira+Code:wght@400;500&display=swap";@import "https://fonts.googleapis.com/css2?family=Material+Symbols+Outlined:opsz,wght,FILL,GRAD@20..48,100..700,0..1,-50..200";:root{--primary-color:#10b981;--primary-hover:#059669;--primary-gradient:linear-gradient(135deg, #10b981, #34d399);--bg-main:#f3f4f6;--bg-surface:#fff;--bg-sidebar:#fff;--text-primary:#111827;--text-secondary:#4b5563;--text-tertiary:#9ca3af;--success-color:#10b981;--warning-color:#f59e0b;--danger-color:#ef4444;--sidebar-width:260px;--topbar-height:64px;--radius-sm:8px;--radius-md:16px;--radius-lg:24px;--radius-pill:9999px;--shadow-sm:0 1px 2px 0 #0000000d;--shadow-md:0 4px 6px -1px #0000000d, 0 2px 4px -1px #00000008;--shadow-lg:0 10px 15px -3px #0000000d, 0 4px 6px -2px #00000006;--shadow-hover:0 20px 25px -5px #0000000d, 0 10px 10px -5px #00000005;--transition:all .2s ease}:root.dark-mode{--shadow-sm:0 1px 2px 0 #00000080;--shadow-md:0 4px 6px -1px #00000080;--shadow-lg:0 10px 15px -3px #0009;--bg-main:#0b111e!important;--bg-surface:#111827!important;--bg-sidebar:#111827!important;--text-primary:#f9fafb!important;--text-secondary:#d1d5db!important;--text-tertiary:#6b7280!important}.dark-mode .btn-secondary{color:#f9fafb!important;background-color:#1f2937!important}.dark-mode .btn-secondary:hover{background-color:#374151!important}.dark-mode .btn-secondary .material-symbols-outlined{color:#f9fafb!important}*{box-sizing:border-box;margin:0;padding:0;font-family:Inter,sans-serif;transition:background-color .3s,color .3s,border-color .3s,box-shadow .3s}body{background-color:var(--bg-main);color:var(--text-primary);-webkit-font-smoothing:antialiased;line-height:1.5}.material-symbols-outlined{font-variation-settings:"FILL" 0, "wght" 400, "GRAD" 0, "opsz" 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var(--transition);flex-direction:column;padding:1.5rem;display:flex}.sidebar-header{align-items:center;gap:12px;margin-bottom:2.5rem;display:flex}.sidebar-logo{white-space:nowrap;background:var(--primary-gradient);-webkit-text-fill-color:transparent;-webkit-background-clip:text;background-clip:text;font-size:1.125rem;font-weight:700}.sidebar-nav{flex-direction:column;gap:8px;display:flex}.nav-item{border-radius:var(--radius-sm);color:var(--text-secondary);transition:var(--transition);cursor:pointer;align-items:center;gap:12px;padding:12px 16px;font-weight:500;text-decoration:none;display:flex}.nav-item:hover{color:var(--primary-color);background-color:#10b9810d}.nav-item.active{background-color:var(--bg-surface);color:var(--primary-color);box-shadow:var(--shadow-sm);position:relative}.nav-item.active:after{content:"";background:var(--primary-color);border-radius:0 4px 4px 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1.5rem;display:flex}.topbar>div{align-items:center;display:flex}.topbar-right{align-items:center;gap:1.25rem;display:flex}.content-area{flex-grow:1;padding:2rem;overflow-y:auto}.card{background:var(--bg-surface);border-radius:var(--radius-md);box-shadow:var(--shadow-md);transition:var(--transition);padding:1.5rem}.card:hover{box-shadow:var(--shadow-hover);transform:translateY(-2px)}.auth-wrapper{background:var(--bg-main);min-height:100vh;display:flex}.auth-content{flex-direction:column;flex:1;justify-content:center;align-items:center;padding:2rem;display:flex}.auth-banner{background:var(--primary-gradient);color:#fff;text-align:center;flex-direction:column;flex:1;justify-content:center;align-items:center;padding:4rem;display:none}@media (width>=1024px){.auth-banner{display:flex}}.auth-box{background:var(--bg-surface);border-radius:var(--radius-lg);box-shadow:var(--shadow-lg);width:100%;max-width:440px;padding:3rem}.auth-tabs{border-bottom:2px solid #e5e7eb;gap:1rem;margin-bottom:2rem;display:flex}.auth-tab{color:var(--text-tertiary);cursor:pointer;transition:var(--transition);border-bottom:2px solid #0000;margin-bottom:-2px;padding:.5rem 1rem;font-weight:600}.auth-tab.active{color:var(--primary-color);border-bottom-color:var(--primary-color)}.form-group{flex-direction:column;gap:.5rem;margin-bottom:1.5rem;display:flex}.form-label{color:var(--text-secondary);font-size:.875rem;font-weight:500}.form-input{border-radius:var(--radius-sm);background:var(--bg-main);width:100%;color:var(--text-primary);transition:var(--transition);border:none;padding:.75rem 1rem;font-size:1rem;box-shadow:inset 0 2px 4px #00000005}.form-input:focus{background:var(--bg-surface);box-shadow:0 0 0 2px #10b98133, var(--shadow-md);outline:none}.btn{border-radius:var(--radius-sm);cursor:pointer;transition:var(--transition);white-space:nowrap;border:none;justify-content:center;align-items:center;gap:.5rem;padding:.625rem 1.25rem;font-size:.8125rem;font-weight:600;text-decoration:none;display:inline-flex}.btn-primary{background:var(--primary-gradient);color:#fff;box-shadow:0 2px 8px #10b9814d}.btn-primary:hover{transform:translateY(-1px);box-shadow:0 4px 12px #10b98166}.btn-secondary{color:var(--text-secondary);background:#f1f5f9}.btn-secondary:hover{color:var(--text-primary);background:#e2e8f0}.btn-sm{padding:.4rem .8rem;font-size:.75rem}.btn-icon{border-radius:50%;padding:.5rem}.btn-danger{color:var(--danger-color);background:#fee2e2}.btn-danger:hover{background:#fecaca}.btn-block{width:100%}.btn.loading{pointer-events:none;position:relative;color:#0000!important}.btn.loading:after{content:"";border:2px solid #ffffff4d;border-top-color:#fff;border-radius:50%;width:16px;height:16px;animation:.8s linear infinite spin;position:absolute}.btn-secondary.loading:after{border-top-color:var(--primary-color);border-color:#10b9814d}@keyframes 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(width<=768px){.grid-cols-2,.grid-cols-3,.grid-cols-4{grid-template-columns:1fr}}.flex{display:flex}.justify-between{justify-content:space-between}.align-center{align-items:center}.gap-4{gap:1rem}.mb-2{margin-bottom:.5rem}.mb-4{margin-bottom:1rem}.mb-6{margin-bottom:1.5rem}.mb-8{margin-bottom:2rem}.hidden{display:none!important}.activity-list{flex-direction:column;gap:1.25rem;display:flex}.activity-item{border-radius:var(--radius-sm);background:var(--bg-main);transition:var(--transition);align-items:flex-start;gap:1rem;padding:1rem;display:flex}.activity-item:hover{transform:translate(4px)}.activity-icon{border-radius:var(--radius-sm);background:var(--bg-surface);width:40px;height:40px;color:var(--primary-color);box-shadow:var(--shadow-sm);justify-content:center;align-items:center;display:flex}.flashcard-viewer{perspective:1000px;cursor:pointer;width:100%;max-width:650px;height:min(50vh,450px);margin:0 auto 3rem}.flashcard-inner{text-align:center;width:100%;height:100%;transform-style:preserve-3d;transition:transform .6s cubic-bezier(.4,0,.2,1);position:relative}.flashcard-inner.flipped{transform:rotateY(180deg)}.hover-danger{transition:var(--transition)}.hover-danger:hover{transform:scale(1.1);color:var(--danger-color)!important}.flashcard-front,.flashcard-back{backface-visibility:hidden;background:var(--bg-surface);border-radius:var(--radius-lg);width:100%;height:100%;box-shadow:var(--shadow-lg);box-sizing:border-box;scrollbar-width:thin;scrollbar-color:#0000001a transparent;flex-direction:column;justify-content:flex-start;align-items:center;padding:2.5rem 2rem;display:flex;position:absolute;overflow-y:auto}.flashcard-back{background:var(--primary-gradient);color:#fff;transform:rotateY(180deg)}.flashcard-back p{color:#fff!important}.click-hint{color:var(--text-tertiary);margin-top:auto;padding:1rem 0 0;font-size:.8rem;transition:opacity .3s}.flashcard-inner.flipped .flashcard-front .click-hint{opacity:0;visibility:hidden}.quiz-option{background:var(--bg-main);border-radius:var(--radius-md);cursor:pointer;transition:var(--transition);margin-bottom:1rem;padding:1rem 1.5rem;font-weight:500}.quiz-option:hover{background:#10b9811a}.quiz-option.selected{background:var(--primary-color);color:#fff;box-shadow:0 4px 14px #10b9814d}.code-split{height:calc(100vh - var(--topbar-height) - 1rem);grid-template-columns:260px 1fr 260px;gap:.5rem;padding:.5rem;display:grid}.ide-editor-group{flex-direction:column;height:100%;display:flex}.ide-main-panel{border-radius:var(--radius-sm);box-shadow:var(--shadow-md);background:#1e1e1e;flex-direction:column;flex:1;display:flex;overflow:hidden}.ide-terminal-panel{background:#000;border-top:1px solid #333;flex-direction:column;height:140px;min-height:40px;max-height:80%;display:flex}.terminal-resizer{cursor:ns-resize;background:0 0;height:4px;transition:background .2s}.terminal-resizer:hover{background:var(--primary-color)}.panel-header{color:#969696;text-transform:uppercase;letter-spacing:.5px;background:#2d2d2d;border-bottom:1px solid #1e1e1e;justify-content:space-between;align-items:center;padding:.5rem 1rem;font-size:.75rem;display:flex}.panel-header.light{background:var(--bg-surface);color:var(--text-secondary);border-bottom-color:#e5e7eb}.editor-container{background:#1e1e1e;flex-direction:column;flex:1;padding:0;display:flex;overflow:hidden}.code-textarea{color:#d4d4d4;resize:none;width:100%;caret-color:var(--primary-color);box-sizing:border-box;background:#1e1e1e;border:none;outline:none;flex:1;padding:1rem;font-family:Fira Code,monospace;font-size:14px;line-height:1.6;height:100%!important}.console-output{color:#4ade80;word-break:break-word;overflow-wrap:break-word;white-space:pre-wrap;flex:1;padding:.75rem 1rem;font-family:Fira Code,monospace;font-size:12px;line-height:1.6;overflow:hidden auto}.toast-container{z-index:9999;flex-direction:column;gap:12px;display:flex;position:fixed;bottom:24px;right:24px}.toast{background:var(--bg-surface);color:var(--text-primary);border-radius:var(--radius-md);box-shadow:var(--shadow-lg);border-left:4px solid var(--primary-color);align-items:center;gap:12px;padding:16px 24px;font-weight:500;animation:.3s cubic-bezier(.4,0,.2,1) slideIn;display:flex}.toast.error{border-left-color:var(--danger-color)}.toast.fade-out{animation:.3s forwards fadeOut}@keyframes slideIn{0%{opacity:0;transform:translate(100%)}to{opacity:1;transform:translate(0)}}@keyframes fadeOut{to{opacity:0;transform:translateY(10px)}}#mobile-overlay{z-index:8;opacity:0;background:#00000080;transition:opacity .3s;display:none;position:fixed;inset:0}@media (width<=1024px){.sidebar{position:fixed;top:0;bottom:0;transform:translate(-100%)}.sidebar.open{transform:translate(0)}.sidebar.open~#mobile-overlay{opacity:1;display:block}}.problem-body h1,.problem-body h2{color:var(--text-primary);margin-bottom:.75rem;font-size:1.125rem}.problem-body h3{margin:1.25rem 0 .5rem;font-size:1rem}.problem-body p{margin-bottom:1rem;font-size:.9rem}.problem-body code{background:var(--bg-main);color:var(--primary-color);border-radius:4px;padding:2px 4px;font-family:Fira Code,monospace;font-size:.85rem}.problem-body pre{background:#f8fafc;border:1px solid #e2e8f0;border-radius:8px;margin:1rem 0;padding:1rem;overflow-x:auto}.example-block{background:#f8fafc;border:1px solid #e2e8f0;border-radius:8px;margin:1rem 0;padding:1rem}.chat-markdown-bubble{color:var(--text-primary);font-size:.875rem;line-height:1.6}.chat-markdown-bubble p{margin-bottom:.75rem}.chat-markdown-bubble p:last-child{margin-bottom:0}.chat-markdown-bubble h1,.chat-markdown-bubble h2,.chat-markdown-bubble h3,.chat-markdown-bubble h4{color:var(--text-primary);margin-top:1.25rem;margin-bottom:.5rem;font-weight:600}.chat-markdown-bubble h1{font-size:1.25rem}.chat-markdown-bubble h2{font-size:1.125rem}.chat-markdown-bubble h3{font-size:1rem}.chat-markdown-bubble ul,.chat-markdown-bubble ol{margin-top:.5rem;margin-bottom:.75rem;padding-left:1.25rem}.chat-markdown-bubble li{margin-bottom:.25rem}.chat-markdown-bubble strong{color:var(--primary-hover);font-weight:600}.chat-markdown-bubble blockquote{border-left:3px solid var(--primary-color);color:var(--text-secondary);margin:.75rem 0;padding-left:.75rem;font-style:italic}.chat-markdown-bubble code{color:var(--primary-hover);background:#10b9811a;border-radius:4px;padding:.125rem .25rem;font-family:Fira Code,monospace;font-size:.85rem}.chat-markdown-bubble pre{border-radius:var(--radius-sm);background:#1e1e2e;border:1px solid #ffffff0d;margin:.75rem 0;padding:.875rem;overflow-x:auto}.chat-markdown-bubble pre code{color:#cdd6f4;background:0 0;padding:0;font-size:.8rem;display:block}.dark-mode .chat-markdown-bubble strong{color:#34d399}.dark-mode .chat-markdown-bubble code{color:#34d399;background:#34d39926}.dark-mode .chat-markdown-bubble pre{background:#111827;border-color:#ffffff1a}