:root{--bg-color: #f8fafc;--panel-bg: rgba(255, 255, 255, .7);--border-color: rgba(0, 0, 0, .08);--text-primary: #1e293b;--text-secondary: #64748b;--accent: #3b82f6;--accent-hover: #2563eb;--success: #10b981;--danger: #ef4444;--sidebar-width: 280px;--header-height: 60px}*{box-sizing:border-box;margin:0;padding:0}body{font-family:Inter,system-ui,-apple-system,sans-serif;background-color:var(--bg-color);color:var(--text-primary);height:100vh;overflow:hidden;background-image:radial-gradient(circle at 15% 50%,rgba(59,130,246,.15),transparent 25%),radial-gradient(circle at 85% 30%,rgba(16,185,129,.1),transparent 25%)}.app-container{display:flex;height:100vh;width:100vw}.sidebar{width:var(--sidebar-width);background:var(--panel-bg);-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);border-right:1px solid var(--border-color);display:flex;flex-direction:column;z-index:10}.sidebar-header{height:var(--header-height);display:flex;align-items:center;padding:0 20px;border-bottom:1px solid var(--border-color)}.sidebar-header h2{font-size:1.1rem;font-weight:600;letter-spacing:.5px}.problem-list{list-style:none;overflow-y:auto;flex:1;padding:10px}.chapter-header{padding:10px;font-size:.8rem;text-transform:uppercase;color:var(--text-secondary);font-weight:700;margin-top:10px;letter-spacing:1px}.chapter-divider{margin-top:16px;padding:0 10px;text-align:center}.chapter-divider hr{border:none;border-top:2px solid var(--accent);margin-bottom:6px}.chapter-divider span{font-size:.75rem;font-weight:700;color:var(--accent);letter-spacing:1px}.problem-item{padding:10px 12px;border-radius:6px;cursor:pointer;margin-bottom:4px;transition:all .2s;display:flex;flex-direction:column}.problem-item:hover{background:#0000000d}.problem-item.active{background:#3b82f633;border-left:3px solid var(--accent)}.problem-item-id{font-weight:600;font-size:.95rem;margin-bottom:4px}.problem-item-section{font-size:.75rem;color:var(--text-secondary)}.main-content{flex:1;display:flex;flex-direction:column;height:100vh;overflow:hidden}.header{height:var(--header-height);background:var(--panel-bg);-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);border-bottom:1px solid var(--border-color);display:flex;align-items:center;justify-content:space-between;padding:0 24px}.header-title{display:flex;align-items:center;gap:12px}.header-title h1{font-size:1.2rem;font-weight:600}.badge{background:#0000000f;padding:4px 8px;border-radius:4px;font-size:.75rem;color:var(--text-secondary)}.run-btn{background:var(--accent);color:#fff;border:none;padding:8px 16px;border-radius:6px;font-weight:500;display:flex;align-items:center;gap:8px;cursor:pointer;transition:all .2s;font-family:inherit}.run-btn:hover:not(:disabled){background:var(--accent-hover);transform:translateY(-1px);box-shadow:0 4px 12px #3b82f64d}.run-btn:disabled{opacity:.5;cursor:not-allowed}.content-wrapper{flex:1;display:flex;flex-direction:column;padding:16px;gap:16px;height:calc(100vh - var(--header-height))}.split-pane{display:flex;gap:16px}.split-vertical{flex:3;min-height:0}.split-horizontal{flex:2;min-height:0}.panel{background:var(--panel-bg);-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);border:1px solid var(--border-color);border-radius:10px;display:flex;flex-direction:column;overflow:hidden;box-shadow:0 4px 20px #0000000d}.problem-desc-panel,.console-panel,.data-panel{flex:1}.editor-panel{flex:2}.plot-panel{flex:1.5}.panel-title{padding:10px 16px;background:#00000008;border-bottom:1px solid var(--border-color);font-size:.85rem;font-weight:600;color:var(--text-secondary);display:flex;align-items:center;gap:8px}.panel-content{flex:1;overflow:auto;position:relative}.code-content{overflow:hidden}.markdown-body{padding:20px;line-height:1.6;font-size:.95rem}.markdown-body pre{background:#0000000a;padding:12px;border-radius:6px;overflow-x:auto;margin:12px 0}.markdown-body code{font-family:Fira Code,monospace;font-size:.85rem;background:#0000000a;padding:2px 4px;border-radius:4px}.markdown-body pre code{background:transparent;padding:0}.markdown-body img{max-width:100%;height:auto;border-radius:8px;border:1px solid var(--border-color);margin:16px 0;display:block;box-shadow:0 4px 12px #0000000d}#console-output{padding:16px;font-family:Fira Code,monospace;font-size:.85rem;white-space:pre-wrap;color:#047857;line-height:1.5}#plot-container{padding:16px;display:flex;justify-content:center;align-items:center;min-height:100%}.empty-state{display:flex;flex-direction:column;align-items:center;justify-content:center;height:100%;color:var(--text-secondary);opacity:.6;gap:12px}.data-input-area{width:100%;height:100%;background:transparent;border:none;color:var(--text-primary);padding:16px;font-family:Fira Code,monospace;font-size:.85rem;resize:none;outline:none}.data-input-area::placeholder{color:#0000004d}#editor-container{height:100%}.cm-editor{height:100%;font-family:Fira Code,monospace}.cm-scroller{overflow:auto}.loading-overlay{position:fixed;top:0;left:0;right:0;bottom:0;background:var(--bg-color);z-index:1000;display:flex;flex-direction:column;align-items:center;justify-content:center;transition:opacity .5s}.spinner-container{position:relative;width:80px;height:80px;margin-bottom:24px}.spinner{position:absolute;top:0;left:0;width:100%;height:100%;border:4px solid rgba(59,130,246,.2);border-top-color:var(--accent);border-radius:50%;animation:spin 1s linear infinite}.spinner-inner{position:absolute;top:15%;left:15%;width:70%;height:70%;border:4px solid rgba(16,185,129,.2);border-bottom-color:var(--success);border-radius:50%;animation:spin 1.5s linear infinite reverse}@keyframes spin{to{transform:rotate(360deg)}}.loading-subtext{color:var(--text-secondary);font-size:.9rem;margin-top:8px}