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solid rgba(216,201,242,.95);border-radius:14px;font-family:var(--sans);font-size:.9rem;line-height:1.55}.rich-html .ans-eli5:before{content:"🧸 ELI5";display:block;font-weight:900;font-size:.68rem;letter-spacing:.1em;text-transform:uppercase;color:#8a6fc0;margin-bottom:6px}.rich-html .ans-eli5 p{margin:0 0 .5em}.rich-html .ans-eli5 p:last-child{margin-bottom:0}.filters{display:grid;grid-template-columns:1fr 1fr;gap:8px}.filters input{grid-column:span 2}.card-list{list-style:none;padding:0;margin:0;display:flex;flex-direction:column;gap:10px}.card-list li a{display:block;background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-lg);padding:14px;text-decoration:none;color:var(--ink);box-shadow:var(--shadow-soft)}.card-list .meta{color:var(--muted);font-size:.8rem;margin-bottom:6px;font-weight:600}.card-list .front{white-space:pre-wrap;overflow-wrap:anywhere;font-size:.92rem;line-height:1.4}.card-list 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auto;width:30px;height:30px;border-radius:999px;display:inline-flex;align-items:center;justify-content:center;background:var(--grape);color:#faf0ec;font-size:.85rem;font-weight:900}.toc-title{line-height:1.3}.reader-head-title{flex:1;min-width:0;text-align:center}.reader-head-course{font-size:.72rem;font-weight:800;letter-spacing:.08em;text-transform:uppercase;color:var(--muted)}.reader-head-chapter{font-weight:800;font-size:.95rem;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.reader-prose{background:var(--paper-2);border:2px solid var(--stroke);border-radius:var(--radius-xl);padding:20px 18px 24px;font-size:1.02rem;line-height:1.65}.reader-prose h1{font-family:var(--serif);font-size:1.7rem;line-height:1.2;color:var(--grape);margin:0 0 10px}.reader-prose h2{font-family:var(--serif);font-size:1.3rem;line-height:1.25;color:var(--grape);margin:1.6em 0 .5em;padding-top:.9em;border-top:2px dashed rgba(234,120,91,.4)}.reader-prose h3{font-size:1.05rem;margin:1.3em 0 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env(safe-area-inset-bottom));background:var(--bg)}.auth-card{width:100%;max-width:360px;display:flex;flex-direction:column;gap:22px}.auth-brand{display:flex;flex-direction:column;align-items:center;text-align:center;gap:6px}.auth-mascot{width:96px;height:96px;object-fit:contain;margin-bottom:4px}.auth-tagline{max-width:280px}.auth-error{color:var(--terra)}.splash-screen{min-height:100vh;min-height:100dvh;display:flex;align-items:center;justify-content:center;background:var(--bg)}.flag-btn{display:inline-flex;align-items:center;justify-content:center;width:34px;height:34px;border:none;background:transparent;color:inherit;opacity:.55;border-radius:999px;cursor:pointer;transition:opacity .15s ease,color .15s ease,background .15s ease}.flag-btn:hover{opacity:.9}.flag-btn.is-flagged{opacity:1;color:#d6453e;background:#d6453e1f}.flag-btn--head{flex:0 0 auto}.flagged-actions{display:flex;gap:8px;margin:8px 0 4px}.flagged-item{display:flex;align-items:center;gap:10px}.flagged-link{flex:1 1 auto;min-width:0}.flagged-back{color:var(--muted, #8a7e78);font-size:.86em;margin-top:2px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}.flagged-unflag{flex:0 0 auto}.top-nav,.reader-sidebar{display:none}.reader-main{display:flex;flex-direction:column;gap:14px;min-width:0}.kbd-hints{display:none}@media(min-width:768px){.page-shell{max-width:760px;padding:28px 28px 40px;gap:18px}.course-list{display:grid;grid-template-columns:1fr 1fr;gap:12px}.module-grid{grid-template-columns:repeat(3,1fr);gap:12px}.toc-list{display:grid;grid-template-columns:1fr 1fr;gap:10px}.reader-prose{padding:36px 44px 44px;font-size:1.06rem}.reader-prose h1{font-size:2rem}.review-cell .math-text{max-height:260px}}@media(min-width:1024px){.page-shell{max-width:980px;padding:20px 32px 48px;gap:20px}.page-shell--wide{max-width:1200px}.page-shell.has-tabs{padding-bottom:48px}.bottom-tabs{display:none}.top-nav{display:flex;align-items:center;gap:18px;padding:10px 0 14px;border-bottom:2px solid rgba(161,168,190,.35);margin-bottom:4px}.top-nav-brand{font-family:var(--serif);font-size:1.5rem;color:var(--grape);text-decoration:none;margin-right:8px}.top-nav-links{display:flex;gap:6px;flex:1}.top-nav-link{padding:9px 16px;border-radius:999px;text-decoration:none;font-weight:700;font-size:.92rem;color:var(--muted);border:1px solid transparent;transition:background .14s ease,color .14s ease}.top-nav-link:hover{color:var(--ink);background:#d8c9f240}.top-nav-link.active{background:#fff7f2;border-color:#5f542038;color:var(--ink)}.avatar--nav{width:40px;height:40px}.avatar--nav img{width:30px;height:30px}.home-hero .topbar{display:none}.course-list{grid-template-columns:repeat(3,1fr)}.home-companion-mascot{width:120px;height:120px}.module-grid{grid-template-columns:repeat(4,1fr)}.reader-layout{display:grid;grid-template-columns:264px minmax(0,1fr);gap:28px;align-items:start}.reader-sidebar{display:block;position:sticky;top:20px;background:var(--paper-2);border:2px solid var(--stroke);border-radius:var(--radius-lg);padding:14px 12px;max-height:calc(100vh - 40px);overflow-y:auto}.reader-sidebar-course{font-size:.72rem;font-weight:900;letter-spacing:.08em;text-transform:uppercase;color:var(--muted);padding:2px 10px 10px}.reader-sidebar-list{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:4px}.reader-sidebar-link{display:flex;align-items:baseline;gap:8px;padding:8px 10px;border-radius:10px;text-decoration:none;font-weight:600;font-size:.88rem;line-height:1.3;color:var(--ink)}.reader-sidebar-link:hover{background:#d8c9f24d}.reader-sidebar-link.active{font-weight:800}.reader-sidebar-num{flex:0 0 auto;font-size:.75rem;font-weight:900;opacity:.55;min-width:16px}.study-card--practice{max-height:calc(100vh - 320px);padding:22px 28px 16px}.practice-controls{max-width:460px;margin:0 auto;width:100%}.kbd-hints{display:flex;justify-content:center;gap:18px;color:var(--muted);font-size:.78rem;font-weight:600}.kbd-hints kbd{font-family:var(--sans);background:var(--paper-2);border:1px solid rgba(161,168,190,.7);border-bottom-width:2px;border-radius:6px;padding:2px 7px;font-size:.74rem}}.launcher{max-width:520px;margin:0 auto;padding:32px 16px calc(32px + env(safe-area-inset-bottom));display:flex;flex-direction:column;gap:22px}.launcher-head{display:flex;flex-direction:column;gap:4px}.launcher-head h1{margin:0;font-weight:400}.launcher-grid{display:grid;grid-template-columns:1fr;gap:12px}@media(min-width:480px){.launcher-grid{grid-template-columns:1fr 1fr}}.app-tile{display:flex;flex-direction:column;gap:6px;padding:18px;background:var(--surface);border:2px solid var(--stroke);border-radius:var(--radius-xl);text-decoration:none;color:var(--ink)}.app-tile:hover{border-color:var(--accent)}.app-tile-icon{width:56px;height:56px;object-fit:contain;margin-bottom:4px}.app-tile-name{font-family:var(--serif);font-size:1.5rem;color:var(--grape);line-height:1.1}.app-tile-desc{color:var(--muted);font-size:.88rem;line-height:1.45}.shell-message{min-height:100vh;min-height:100dvh;display:flex;align-items:center;justify-content:center;padding:24px 16px calc(24px + env(safe-area-inset-bottom))}.shell-message-card{width:100%;max-width:400px;display:flex;flex-direction:column;align-items:center;text-align:center;gap:12px}.shell-message-card h1{margin:0;font-weight:400}