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@font-face{font-family:Geist;font-style:normal;font-weight:100 900;font-display:swap;src:url(../media/8a480f0b521d4e75-s.8e0177b5.woff2)format("woff2");unicode-range:U+301,U+400-45F,U+490-491,U+4B0-4B1,U+2116}@font-face{font-family:Geist;font-style:normal;font-weight:100 900;font-display:swap;src:url(../media/7178b3e590c64307-s.b97b3418.woff2)format("woff2");unicode-range:U+100-2BA,U+2BD-2C5,U+2C7-2CC,U+2CE-2D7,U+2DD-2FF,U+304,U+308,U+329,U+1D00-1DBF,U+1E00-1E9F,U+1EF2-1EFF,U+2020,U+20A0-20AB,U+20AD-20C0,U+2113,U+2C60-2C7F,U+A720-A7FF}@font-face{font-family:Geist;font-style:normal;font-weight:100 900;font-display:swap;src:url(../media/caa3a2e1cccd8315-s.p.853070df.woff2)format("woff2");unicode-range:U+??,U+131,U+152-153,U+2BB-2BC,U+2C6,U+2DA,U+2DC,U+304,U+308,U+329,U+2000-206F,U+20AC,U+2122,U+2191,U+2193,U+2212,U+2215,U+FEFF,U+FFFD}@font-face{font-family:Geist Fallback;src:local(Arial);ascent-override:95.94%;descent-override:28.16%;line-gap-override:0.0%;size-adjust:104.76%}.geist_a71539c9-module__T19VSG__className{font-family:Geist,Geist Fallback;font-style:normal}.geist_a71539c9-module__T19VSG__variable{--font-geist-sans:"Geist","Geist Fallback"}
@font-face{font-family:Geist Mono;font-style:normal;font-weight:100 900;font-display:swap;src:url(../media/4fa387ec64143e14-s.c1fdd6c2.woff2)format("woff2");unicode-range:U+301,U+400-45F,U+490-491,U+4B0-4B1,U+2116}@font-face{font-family:Geist Mono;font-style:normal;font-weight:100 900;font-display:swap;src:url(../media/bbc41e54d2fcbd21-s.799d8ef8.woff2)format("woff2");unicode-range:U+100-2BA,U+2BD-2C5,U+2C7-2CC,U+2CE-2D7,U+2DD-2FF,U+304,U+308,U+329,U+1D00-1DBF,U+1E00-1E9F,U+1EF2-1EFF,U+2020,U+20A0-20AB,U+20AD-20C0,U+2113,U+2C60-2C7F,U+A720-A7FF}@font-face{font-family:Geist Mono;font-style:normal;font-weight:100 900;font-display:swap;src:url(../media/797e433ab948586e-s.p.dbea232f.woff2)format("woff2");unicode-range:U+??,U+131,U+152-153,U+2BB-2BC,U+2C6,U+2DA,U+2DC,U+304,U+308,U+329,U+2000-206F,U+20AC,U+2122,U+2191,U+2193,U+2212,U+2215,U+FEFF,U+FFFD}@font-face{font-family:Geist Mono Fallback;src:local(Arial);ascent-override:74.67%;descent-override:21.92%;line-gap-override:0.0%;size-adjust:134.59%}.geist_mono_8d43a2aa-module__8Li5zG__className{font-family:Geist Mono,Geist Mono Fallback;font-style:normal}.geist_mono_8d43a2aa-module__8Li5zG__variable{--font-geist-mono:"Geist Mono","Geist Mono Fallback"}
:root{--bg-primary:#fafafa;--bg-secondary:#fff;--bg-tertiary:#f2f2f7;--text-primary:#1d1d1f;--text-secondary:#6e6e73;--text-tertiary:#aeaeb2;--accent-color:#0071e3;--accent-hover:#0077ed;--accent-light:#0071e314;--accent-gradient:linear-gradient(135deg,#0071e3 0%,#5856d6 100%);--success-color:#34c759;--warning-color:#ff9500;--danger-color:#ff3b30;--border-color:#00000014;--bg-overlay:#fafafae0;--glass-bg:#ffffffb8;--glass-border:#ffffff80;--glass-shadow:0 8px 32px #0000000f;--radius-xs:6px;--radius-sm:10px;--radius-md:16px;--radius-lg:24px;--radius-xl:32px;--radius-pill:980px;--shadow-xs:0 1px 2px #0000000a;--shadow-sm:0 2px 8px #0000000a;--shadow-md:0 4px 16px #0000000f,0 1px 4px #0000000a;--shadow-lg:0 12px 40px #00000014,0 4px 12px #0000000a;--shadow-xl:0 24px 64px #0000001f;--spacing-xs:.5rem;--spacing-sm:1rem;--spacing-md:1.5rem;--spacing-lg:2.5rem;--spacing-xl:4rem;--spacing-2xl:6rem;--spacing-3xl:8rem;--font-family:"Inter",-apple-system,BlinkMacSystemFont,"Segoe 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var(--spacing-lg);background:var(--glass-bg);-webkit-backdrop-filter:saturate(180%)blur(20px);border-bottom:1px solid var(--border-color);z-index:1000;justify-content:space-between;align-items:center;height:64px;animation:.5s both fadeInDown;display:flex;position:fixed;top:0}.nav-logo a,.nav-logo{letter-spacing:-.03em;background:var(--accent-gradient);-webkit-text-fill-color:transparent;-webkit-background-clip:text;background-clip:text;font-size:1.25rem;font-weight:700}.nav-links{align-items:center;gap:var(--spacing-md);font-size:.9rem;font-weight:500;display:flex}.nav-links a:not(.btn){padding:4px 0;position:relative}.nav-links a:after{content:"";background:var(--accent-gradient);border-radius:1px;width:0;height:2px;transition:width .3s cubic-bezier(.16,1,.3,1);position:absolute;bottom:-2px;left:0}.nav-links a:hover:after{width:100%}.nav-links a:hover{color:var(--accent-color)}.heading-xl{letter-spacing:-.04em;margin-bottom:var(--spacing-sm);font-size:clamp(2.8rem,6vw,5rem);font-weight:800;line-height:1.05}.heading-lg{letter-spacing:-.03em;margin-bottom:var(--spacing-sm);font-size:clamp(1.8rem,3.5vw,2.8rem);font-weight:700;line-height:1.15}.heading-md{letter-spacing:-.02em;font-size:clamp(1.2rem,2vw,1.6rem);font-weight:600;line-height:1.3}.text-lead{color:var(--text-secondary);max-width:640px;margin:0 auto var(--spacing-lg);font-size:clamp(1.05rem,1.8vw,1.35rem);font-weight:400;line-height:1.7}.gradient-text{background:var(--accent-gradient);-webkit-text-fill-color:transparent;-webkit-background-clip:text;background-clip:text}.btn{border-radius:var(--radius-pill);cursor:pointer;justify-content:center;align-items:center;gap:8px;padding:12px 28px;font-size:.95rem;font-weight:600;transition:all .25s cubic-bezier(.16,1,.3,1);display:inline-flex;position:relative;overflow:hidden}.btn:after{content:"";background:#fff0;transition:background .25s;position:absolute;inset:0}.btn:active:after{background:#00000014}.btn-primary{background:var(--accent-gradient);-webkit-text-fill-color:white;color:#fff;background-size:200% 200%;-webkit-background-clip:padding-box;background-clip:padding-box;box-shadow:0 4px 14px #0071e359}.nav-links .btn:after{display:none}.btn-primary:hover{transform:translateY(-2px);box-shadow:0 6px 20px #0071e373}.btn-primary:active{transform:translateY(0)}.btn-secondary{background:var(--bg-secondary);color:var(--text-primary);border:1px solid var(--border-color);box-shadow:var(--shadow-xs)}.btn-secondary:hover{background:var(--bg-tertiary);box-shadow:var(--shadow-sm);transform:translateY(-1px)}.btn-secondary:active{transform:translateY(0)}.btn-ghost{color:var(--accent-color);background:0 0;padding:8px 16px}.btn-ghost:hover{background:var(--accent-light)}.btn-lg{padding:16px 36px;font-size:1.05rem}.btn-sm{padding:8px 18px;font-size:.85rem}.btn:disabled{opacity:.5;cursor:not-allowed;transform:none!important}.card{background:var(--bg-secondary);border-radius:var(--radius-lg);padding:var(--spacing-lg);box-shadow:var(--shadow-sm);border:1px solid var(--border-color);transition:transform .35s cubic-bezier(.16,1,.3,1),box-shadow .35s;position:relative;overflow:hidden}.card:hover{box-shadow:var(--shadow-lg);transform:translateY(-6px)}.card-glass{background:var(--glass-bg);-webkit-backdrop-filter:blur(16px);border:1px solid var(--glass-border);border-radius:var(--radius-lg);padding:var(--spacing-lg);box-shadow:var(--glass-shadow);transition:transform .35s cubic-bezier(.16,1,.3,1),box-shadow .35s}.card-glass:hover{transform:translateY(-4px)}.badge{border-radius:var(--radius-pill);text-transform:uppercase;letter-spacing:.05em;align-items:center;gap:4px;padding:4px 12px;font-size:.75rem;font-weight:600;display:inline-flex}.badge-accent{background:var(--accent-light);color:var(--accent-color)}.badge-success{color:var(--success-color);background:#34c7591a}.badge-warning{color:var(--warning-color);background:#ff95001a}.form-group{margin-bottom:var(--spacing-md);flex-direction:column;gap:6px;display:flex}.form-label{color:var(--text-secondary);letter-spacing:.01em;font-size:.85rem;font-weight:600}.form-input{border-radius:var(--radius-sm);border:1.5px solid var(--border-color);background-color:var(--bg-primary);width:100%;color:var(--text-primary);padding:14px 16px;font-size:.95rem;transition:all .25s}.form-input:focus{border-color:var(--accent-color);box-shadow:0 0 0 4px var(--accent-light)}.form-input::placeholder{color:var(--text-tertiary)}.section{padding:var(--spacing-3xl)0}.section-header{text-align:center;max-width:700px;margin:0 auto var(--spacing-xl)}.section-header .badge{margin-bottom:var(--spacing-sm)}.section-header p{color:var(--text-secondary);font-size:1.1rem;line-height:1.7}.hero-section{text-align:center;padding:140px var(--spacing-md)var(--spacing-3xl);flex-direction:column;justify-content:center;align-items:center;min-height:100vh;display:flex;position:relative}.hero-section .badge{margin-bottom:var(--spacing-md);animation:.6s cubic-bezier(.16,1,.3,1) both fadeInUp}.hero-section .heading-xl{animation:.7s cubic-bezier(.16,1,.3,1) .1s both fadeInUp}.hero-section .text-lead{animation:.7s cubic-bezier(.16,1,.3,1) .2s both fadeInUp}.hero-actions{gap:var(--spacing-sm);margin-top:var(--spacing-sm);flex-wrap:wrap;justify-content:center;animation:.7s cubic-bezier(.16,1,.3,1) .35s both fadeInUp;display:flex}.hero-stats{gap:var(--spacing-xl);margin-top:var(--spacing-2xl);animation:.8s cubic-bezier(.16,1,.3,1) .5s both fadeInUp;display:flex}.hero-stat{text-align:center}.hero-stat-number{letter-spacing:-.03em;background:var(--accent-gradient);-webkit-text-fill-color:transparent;-webkit-background-clip:text;background-clip:text;font-size:2.5rem;font-weight:800}.hero-stat-label{color:var(--text-secondary);margin-top:2px;font-size:.85rem;font-weight:500}.feature-grid{gap:var(--spacing-lg);grid-template-columns:repeat(auto-fit,minmax(320px,1fr));display:grid}.feature-card{padding:var(--spacing-xl)var(--spacing-lg)}.feature-icon{border-radius:var(--radius-md);width:56px;height:56px;margin-bottom:var(--spacing-md);background:var(--accent-light);color:var(--accent-color);justify-content:center;align-items:center;font-size:1.5rem;transition:transform .3s;display:flex}.feature-card:hover .feature-icon{transform:scale(1.1)rotate(-3deg)}.feature-card h3{letter-spacing:-.01em;margin-bottom:8px;font-size:1.25rem;font-weight:700}.feature-card p{color:var(--text-secondary);font-size:.95rem;line-height:1.65}.testimonial-grid{gap:var(--spacing-lg);grid-template-columns:repeat(auto-fit,minmax(300px,1fr));display:grid}.testimonial-card{padding:var(--spacing-lg)}.testimonial-card blockquote{color:var(--text-secondary);margin-bottom:var(--spacing-md);font-size:1rem;font-style:italic;line-height:1.7}.testimonial-author{align-items:center;gap:12px;display:flex}.testimonial-avatar{background:var(--accent-gradient);color:#fff;border-radius:50%;justify-content:center;align-items:center;width:44px;height:44px;font-size:1rem;font-weight:700;display:flex}.testimonial-author-info strong{font-size:.95rem;display:block}.testimonial-author-info span{color:var(--text-tertiary);font-size:.8rem}.cta-section{text-align:center;padding:var(--spacing-3xl)var(--spacing-md);background:var(--accent-gradient);border-radius:var(--radius-xl);margin:0 var(--spacing-md)var(--spacing-3xl);color:#fff;background-size:400% 400%;animation:8s infinite gradientShift}.cta-section h2{letter-spacing:-.03em;margin-bottom:var(--spacing-sm);font-size:clamp(1.8rem,3.5vw,2.8rem);font-weight:700}.cta-section p{opacity:.9;max-width:500px;margin:0 auto var(--spacing-lg);font-size:1.1rem}.cta-section .btn{color:#0071e3;background:#fff;box-shadow:0 4px 14px #0003}.cta-section .btn:hover{transform:translateY(-2px);box-shadow:0 8px 24px #00000040}.footer{padding:var(--spacing-xl)var(--spacing-lg);text-align:center;border-top:1px solid var(--border-color);color:var(--text-tertiary);margin-top:auto;font-size:.85rem}.footer-links{gap:var(--spacing-lg);margin-bottom:var(--spacing-md);flex-wrap:wrap;justify-content:center;display:flex}.footer-links a{color:var(--text-secondary);font-weight:500;transition:color .2s}.footer-links a:hover{color:var(--accent-color)}.content-grid{gap:var(--spacing-lg);grid-template-columns:repeat(auto-fill,minmax(300px,1fr));display:grid}.content-grid-books{gap:var(--spacing-lg);grid-template-columns:repeat(auto-fill,minmax(220px,1fr));display:grid}.course-card{border-radius:var(--radius-lg);padding:0;overflow:hidden}.course-card-image{background:var(--accent-gradient);color:#fff9;background-size:200% 200%;justify-content:center;align-items:center;height:180px;display:flex;position:relative;overflow:hidden}.course-card-image img{object-fit:cover;width:100%;height:100%}.course-card-body{padding:var(--spacing-md)var(--spacing-lg)var(--spacing-lg)}.course-card-body h3{letter-spacing:-.01em;margin-bottom:6px;font-size:1.1rem;font-weight:700}.course-card-body p{color:var(--text-secondary);margin-bottom:var(--spacing-md);font-size:.88rem;line-height:1.6}.course-card-meta{align-items:center;gap:var(--spacing-sm);color:var(--text-tertiary);margin-bottom:var(--spacing-md);font-size:.8rem;display:flex}.topic-card{border:1px solid var(--border-color);padding:14px 18px;transition:all .15s}.topic-card:hover{border-color:var(--accent-color);background:var(--bg-tertiary);transform:translateY(-1px);box-shadow:0 2px 12px #6366f114}.lesson-item:hover{background:var(--bg-tertiary)}.subtopic-notes-content h1,.subtopic-notes-content h2,.subtopic-notes-content h3{color:var(--text-primary);margin-top:1.2em;margin-bottom:.4em}.subtopic-notes-content p{margin-bottom:.8em}.subtopic-notes-content ul,.subtopic-notes-content ol{margin-bottom:.8em;padding-left:1.5em}.subtopic-notes-content code{background:var(--bg-tertiary);border-radius:4px;padding:2px 6px;font-size:.88em}.subtopic-notes-content pre{background:var(--bg-tertiary);border-radius:10px;margin-bottom:1em;padding:14px 18px;overflow-x:auto}.subtopic-notes-content pre code{background:0 0;padding:0}.video-player-container{aspect-ratio:16/9;border:1px solid var(--border-color);background:#000;border-radius:16px;width:100%;margin-bottom:16px;position:relative;overflow:hidden;box-shadow:0 4px 24px #0000001f}.subtopic-tab-bar{border-bottom:1px solid var(--border-color);scrollbar-width:none;gap:6px;margin-bottom:4px;padding:10px 0;display:flex;overflow-x:auto}.subtopic-tab-bar::-webkit-scrollbar{display:none}.subtopic-tab{background:var(--bg-tertiary);color:var(--text-tertiary);cursor:pointer;white-space:nowrap;border:none;border-radius:10px;flex-shrink:0;align-items:center;gap:6px;padding:8px 16px;font-size:.85rem;font-weight:500;transition:all .15s;display:flex}.subtopic-tab.active{background:var(--accent-color);color:#fff;font-weight:600}.tutor-chat-container{flex-direction:column;min-height:400px;max-height:60vh;display:flex}.tutor-chat-messages{flex-direction:column;flex:1;gap:16px;padding:16px 0;display:flex;overflow-y:auto}.chat-bubble{align-items:flex-end;gap:10px;display:flex}.chat-bubble.user{justify-content:flex-end}.chat-bubble.ai{justify-content:flex-start}.chat-avatar{border-radius:50%;flex-shrink:0;justify-content:center;align-items:center;width:32px;height:32px;display:flex}.chat-avatar.ai{color:#fff;background:linear-gradient(135deg,#667eea,#764ba2)}.chat-avatar.user{background:var(--accent-color);color:#fff}.chat-bubble-content{flex-direction:column;gap:4px;max-width:75%;display:flex}.chat-label{color:var(--text-tertiary);font-size:.72rem;font-weight:500}.chat-text{border-radius:16px;padding:12px 16px;font-size:.9rem;line-height:1.6}.chat-text.user{background:var(--accent-color);color:#fff;border-bottom-right-radius:4px}.chat-text.ai{background:var(--bg-tertiary);color:var(--text-primary);word-break:break-word;overflow-wrap:anywhere;border-bottom-left-radius:4px}.chat-text.ai p{margin-bottom:.5em}.chat-text.ai p:last-child{margin-bottom:0}.chat-text.ai .katex-display{padding:4px 0;overflow:auto hidden}.chat-text.ai .katex-display>.katex{white-space:nowrap}.typing-dots{gap:4px;padding:4px 0;display:flex}.typing-dots span{background:var(--text-tertiary);border-radius:50%;width:7px;height:7px;animation:1.2s ease-in-out infinite typingBounce}.typing-dots span:nth-child(2){animation-delay:.2s}.typing-dots span:nth-child(3){animation-delay:.4s}@keyframes typingBounce{0%,80%,to{opacity:.3;transform:scale(.8)}40%{opacity:1;transform:scale(1)}}.tutor-input-area{border-top:1px solid var(--border-color);align-items:center;gap:10px;margin-top:8px;padding:12px 0 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