:root{--bg-dark:#090d16;--bg-card:#0f172a;--bg-card-hover:#162038;--bg-subtle:#1e293b;--border-color:#ffffff14;--border-glow:#6366f140;--accent-primary:#6366f1;--accent-primary-hover:#4f46e5;--accent-cyan:#06b6d4;--accent-emerald:#10b981;--accent-amber:#f59e0b;--accent-rose:#f43f5e;--text-main:#f8fafc;--text-muted:#94a3b8;--text-subtle:#64748b;--font-family:-apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif}*{box-sizing:border-box;margin:0;padding:0}body{background-color:var(--bg-dark);color:var(--text-main);font-family:var(--font-family);-webkit-font-smoothing:antialiased;min-height:100vh;line-height:1.5}::-webkit-scrollbar{width:6px;height:6px}::-webkit-scrollbar-track{background:var(--bg-dark)}::-webkit-scrollbar-thumb{background:var(--bg-subtle);border-radius:4px}.app-container{flex-direction:column;min-height:100vh;display:flex}.top-nav{border-bottom:1px solid var(--border-color);-webkit-backdrop-filter:blur(12px);backdrop-filter:blur(12px);z-index:50;background:#090d16d9;justify-content:space-between;align-items:center;height:64px;padding:0 1.5rem;display:flex;position:sticky;top:0}.brand{background:linear-gradient(135deg,#a5b4fc,#6366f1,#38bdf8);-webkit-text-fill-color:transparent;cursor:pointer;-webkit-background-clip:text;align-items:center;gap:.75rem;font-size:1.25rem;font-weight:700;display:flex}.nav-links{align-items:center;gap:.5rem;display:flex}.nav-tab{color:var(--text-muted);cursor:pointer;background:0 0;border:1px solid #0000;border-radius:8px;align-items:center;gap:.4rem;padding:.45rem .9rem;font-size:.875rem;font-weight:500;transition:all .2s;display:flex}.nav-tab:hover{color:var(--text-main);background:#ffffff0a}.nav-tab.active{color:var(--text-main);background:var(--bg-subtle);border-color:var(--border-color)}.status-badge{color:#a5b4fc;background:#6366f11f;border:1px solid #6366f140;border-radius:9999px;align-items:center;gap:.4rem;padding:.25rem .6rem;font-size:.75rem;display:flex}.main-content{flex:1;width:100%;max-width:1400px;margin:0 auto;padding:1.5rem}.glass-card{background:var(--bg-card);border:1px solid var(--border-color);border-radius:12px;padding:1.25rem;transition:border-color .2s;box-shadow:0 8px 24px -4px #0000004d}.glass-card:hover{border-color:var(--border-glow)}.btn-primary{color:#fff;cursor:pointer;background:linear-gradient(135deg,#6366f1,#4f46e5);border:none;border-radius:8px;align-items:center;gap:.5rem;padding:.6rem 1.2rem;font-size:.875rem;font-weight:500;transition:all .2s;display:inline-flex;box-shadow:0 4px 12px #6366f140}.btn-primary:hover{background:linear-gradient(135deg,#4f46e5,#4338ca);transform:translateY(-1px)}.btn-secondary{background:var(--bg-subtle);color:var(--text-main);border:1px solid var(--border-color);cursor:pointer;border-radius:8px;align-items:center;gap:.5rem;padding:.6rem 1.2rem;font-size:.875rem;font-weight:500;transition:all .2s;display:inline-flex}.btn-secondary:hover{background:var(--bg-card-hover);border-color:#ffffff26}.btn-ghost{color:var(--text-muted);cursor:pointer;background:0 0;border:none;border-radius:6px;align-items:center;gap:.35rem;padding:.4rem .6rem;transition:all .2s;display:flex}.btn-ghost:hover{color:var(--text-main);background:#ffffff0d}.hero-box{border:1px solid var(--border-color);background:radial-gradient(circle at 100% 0,#6366f126,#0000 50%),linear-gradient(#1e293b66 0%,#0f172acc 100%);border-radius:16px;margin-bottom:2rem;padding:2.25rem;position:relative;overflow:hidden}.hero-title{letter-spacing:-.02em;margin-bottom:.5rem;font-size:2rem;font-weight:800}.hero-subtitle{color:var(--text-muted);max-width:650px;margin-bottom:1.5rem;font-size:1.05rem}.grid-2{grid-template-columns:repeat(2,1fr);gap:1.25rem;display:grid}.grid-3{grid-template-columns:repeat(3,1fr);gap:1.25rem;display:grid}.grid-4{grid-template-columns:repeat(4,1fr);gap:1rem;display:grid}@media (width<=900px){.grid-2,.grid-3,.grid-4{grid-template-columns:1fr}}.action-card{background:var(--bg-card);border:1px solid var(--border-color);cursor:pointer;border-radius:12px;flex-direction:column;gap:.6rem;padding:1.25rem;transition:all .2s;display:flex}.action-card:hover{border-color:var(--accent-primary);background:var(--bg-card-hover);transform:translateY(-2px)}.action-icon-wrapper{border-radius:8px;justify-content:center;align-items:center;width:40px;height:40px;display:flex}.workspace-grid{grid-template-columns:300px 1fr 320px;gap:1.25rem;height:calc(100vh - 120px);display:grid}@media (width<=1100px){.workspace-grid{grid-template-columns:1fr;height:auto}}.column-panel{flex-direction:column;height:100%;display:flex;overflow:hidden}.scroll-panel{flex:1;padding-right:.25rem;overflow-y:auto}.chat-container{flex-direction:column;height:100%;display:flex}.chat-messages{flex-direction:column;flex:1;gap:1rem;padding:1rem;display:flex;overflow-y:auto}.message-bubble{word-break:break-word;border-radius:12px;max-width:85%;padding:.85rem 1.1rem;font-size:.925rem;line-height:1.55}.message-bubble.user{color:#fff;background:#4f46e5;border-bottom-right-radius:2px;align-self:flex-end}.message-bubble.assistant{background:var(--bg-subtle);border:1px solid var(--border-color);color:var(--text-main);border-bottom-left-radius:2px;align-self:flex-start}.citation-box{border-left:3px solid var(--accent-cyan);color:var(--text-muted);background:#00000040;border-radius:4px;margin-top:.75rem;padding:.6rem;font-size:.785rem}.chat-input-bar{border-top:1px solid var(--border-color);background:var(--bg-card);gap:.5rem;padding:1rem;display:flex}.chat-input{background:var(--bg-dark);border:1px solid var(--border-color);color:var(--text-main);border-radius:8px;outline:none;flex:1;padding:.65rem 1rem;font-size:.9rem}.chat-input:focus{border-color:var(--accent-primary)}.quiz-card{background:var(--bg-card);border:1px solid var(--border-color);border-radius:12px;margin-bottom:1.25rem;padding:1.5rem}.quiz-option{border:1px solid var(--border-color);background:var(--bg-subtle);cursor:pointer;border-radius:8px;align-items:center;gap:.75rem;margin-bottom:.5rem;padding:.75rem 1rem;font-size:.925rem;transition:all .2s;display:flex}.quiz-option:hover{background:#6366f114;border-color:#6366f166}.quiz-option.selected{border-color:var(--accent-primary);background:#6366f126}.quiz-option.correct{border-color:var(--accent-emerald);color:#34d399;background:#10b98126}.quiz-option.incorrect{border-color:var(--accent-rose);color:#fb7185;background:#f43f5e26}.plan-task-item{background:var(--bg-subtle);border:1px solid var(--border-color);border-radius:8px;gap:1rem;margin-bottom:.75rem;padding:1rem;display:flex}.task-badge{text-transform:uppercase;border-radius:4px;padding:.2rem .5rem;font-size:.75rem;font-weight:600}.dropzone{text-align:center;cursor:pointer;background:#6366f108;border:2px dashed #6366f166;border-radius:12px;padding:2.5rem 1.5rem;transition:all .2s}.dropzone:hover,.dropzone.drag-active{border-color:var(--accent-primary);background:#6366f114}.skeleton{background:linear-gradient(90deg,#1e293b 25%,#334155 50%,#1e293b 75%) 0 0/200% 100%;border-radius:4px;animation:1.5s infinite shimmer}@keyframes shimmer{0%{background-position:-200% 0}to{background-position:200% 0}}.badge-tag{color:var(--text-muted);background:#ffffff0f;border-radius:4px;padding:.15rem .45rem;font-size:.72rem}