@import"https://fonts.googleapis.com/css2?family=Instrument+Serif:ital@0;1&family=Geist:wght@300;400;500;600;700&family=JetBrains+Mono:wght@400;500&display=swap";:root{--bg: #f6f3ee;--bg-elev: #fbf9f5;--bg-card: #ffffff;--bg-sunken: #efebe3;--bg-inverse: #1a1814;--ink: #1a1814;--ink-2: #4a463e;--ink-3: #7a7468;--ink-4: #a8a294;--ink-on-dark: #f6f3ee;--line: #e6e1d6;--line-2: #d8d2c4;--line-strong: #1a1814;--coral-50: oklch(.97 .02 35);--coral-100: oklch(.94 .05 35);--coral-200: oklch(.88 .1 35);--coral-400: oklch(.74 .18 35);--coral-500: oklch(.68 .22 32);--coral-600: oklch(.6 .22 30);--coral-700: oklch(.5 .18 28);--sky-100: oklch(.94 .04 235);--sky-300: oklch(.82 .1 235);--sky-500: oklch(.65 .14 235);--sky-700: oklch(.45 .13 235);--green-100: oklch(.94 .05 150);--green-300: oklch(.82 .13 150);--green-500: oklch(.62 .16 148);--green-700: oklch(.45 .14 148);--amber-100: oklch(.95 .05 75);--amber-300: oklch(.85 .13 75);--amber-500: oklch(.74 .16 65);--amber-700: oklch(.55 .16 55);--red-100: oklch(.94 .05 25);--red-500: oklch(.62 .21 25);--heat-0: #efebe3;--heat-1: oklch(.92 .06 75);--heat-2: oklch(.86 .11 65);--heat-3: oklch(.78 .16 50);--heat-4: oklch(.68 .2 35);--heat-5: oklch(.58 .22 28);--serif: "Instrument Serif", "Iowan Old Style", Georgia, serif;--sans: "Geist", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;--mono: "JetBrains Mono", "SF Mono", Consolas, monospace;--r-sm: 6px;--r-md: 10px;--r-lg: 14px;--r-xl: 20px;--r-2xl: 28px;--shadow-sm: 0 1px 2px rgba(26, 24, 20, .04), 0 0 0 1px var(--line);--shadow-md: 0 6px 24px -8px rgba(26, 24, 20, .12), 0 0 0 1px var(--line);--shadow-lg: 0 18px 48px -12px rgba(26, 24, 20, .18), 0 0 0 1px var(--line);--shadow-pop: 0 24px 60px -16px rgba(26, 24, 20, .28)}*{box-sizing:border-box}body{margin:0;font-family:var(--sans);color:var(--ink);background:var(--bg);font-feature-settings:"ss01","cv11";-webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility}html,body,#root{height:100%}button{font-family:inherit;cursor:pointer}a{text-decoration:none;color:inherit}.btn{display:inline-flex;align-items:center;gap:8px;height:40px;padding:0 18px;border-radius:999px;border:none;font-size:14px;font-weight:500;letter-spacing:-.01em;cursor:pointer;transition:transform .08s,background .12s;white-space:nowrap}.btn:active{transform:translateY(1px)}.btn-primary{background:var(--ink);color:var(--ink-on-dark)}.btn-primary:hover{background:#2a2620}.btn-coral{background:var(--coral-500);color:#fff;box-shadow:0 1px #d41101 inset,0 -1px #ff9878 inset;box-shadow:0 1px #d41101 inset,0 -1px oklch(.78 .18 38) inset}.btn-coral:hover{background:var(--coral-600)}.btn-ghost{background:transparent;color:var(--ink);border:1px solid var(--line-2)}.btn-ghost:hover{background:var(--bg-elev)}.btn-sm{height:32px;padding:0 12px;font-size:13px}.btn-lg{height:48px;padding:0 22px;font-size:15px}.card{background:var(--bg-card);border:1px solid var(--line);border-radius:var(--r-lg)}.chip{display:inline-flex;align-items:center;gap:6px;height:26px;padding:0 10px;border-radius:999px;background:var(--bg-elev);border:1px solid var(--line);font-size:12px;font-weight:500;color:var(--ink-2);letter-spacing:.01em}.chip-mono{font-family:var(--mono);font-size:11px;letter-spacing:0}.chip-coral{background:var(--coral-100);border-color:var(--coral-200);color:var(--coral-700)}.chip-sky{background:var(--sky-100);border-color:#abd8f3;color:var(--sky-700)}.chip-green{background:var(--green-100);border-color:#b1dfb9;color:var(--green-700)}.chip-dark{background:var(--ink);border-color:var(--ink);color:var(--ink-on-dark)}.eyebrow{font-family:var(--mono);font-size:11px;letter-spacing:.08em;text-transform:uppercase;color:var(--ink-3)}.h-display{font-family:var(--serif);font-weight:400;font-size:56px;line-height:1.02;letter-spacing:-.02em;color:var(--ink);margin:0}.h-display .it{font-style:italic;color:var(--coral-600)}.h-1{font-family:var(--serif);font-weight:400;font-size:40px;line-height:1.05;letter-spacing:-.02em;margin:0}.h-1 .it{font-style:italic}.h-2{font-family:var(--serif);font-weight:400;font-size:28px;line-height:1.1;letter-spacing:-.01em;margin:0}.h-3{font-family:var(--sans);font-weight:600;font-size:16px;letter-spacing:-.01em;margin:0}.body{font-size:14px;line-height:1.55;color:var(--ink-2)}.muted{color:var(--ink-3)}.tiny{font-size:12px;color:var(--ink-3)}.mono{font-family:var(--mono)}.sidebar{width:232px;flex-shrink:0;background:var(--bg);border-right:1px solid var(--line);display:flex;flex-direction:column;padding:18px 14px;height:100%}.brand{display:flex;align-items:center;gap:9px;padding:6px 8px 18px}.brand-mark{width:26px;height:26px;border-radius:8px;background:var(--ink);color:var(--ink-on-dark);display:grid;place-items:center;font-family:var(--serif);font-style:italic;font-size:17px;font-weight:400;position:relative}.brand-mark:after{content:"";position:absolute;top:-3px;right:-3px;bottom:-3px;left:-3px;border-radius:11px;border:1px solid var(--coral-500);opacity:.35}.brand-name{font-family:var(--serif);font-size:19px;letter-spacing:-.01em}.brand-name .it{font-style:italic}.nav{display:flex;flex-direction:column;gap:1px}.nav-item{display:flex;align-items:center;gap:10px;padding:8px 10px;border-radius:var(--r-md);font-size:13px;color:var(--ink-2);cursor:pointer;font-weight:500;border:none;background:transparent;width:100%;text-align:left}.nav-item:hover{background:var(--bg-elev)}.nav-item.active{background:var(--ink);color:var(--ink-on-dark)}.nav-section{font-family:var(--mono);font-size:10px;letter-spacing:.1em;text-transform:uppercase;color:var(--ink-4);padding:16px 10px 6px}.nav-icon{width:16px;height:16px;display:grid;place-items:center;flex-shrink:0}.topbar{height:60px;border-bottom:1px solid var(--line);padding:0 28px;display:flex;align-items:center;justify-content:space-between;background:var(--bg);flex-shrink:0}.heat-cell{aspect-ratio:1;border-radius:5px;border:1px solid rgba(0,0,0,.04);position:relative}.ai-msg{background:var(--bg-elev);border:1px solid var(--line);border-radius:4px 14px 14px;padding:12px 14px;font-size:13px;line-height:1.55;color:var(--ink);position:relative;white-space:pre-wrap}.user-msg{align-self:flex-end;max-width:85%;background:var(--ink);color:var(--ink-on-dark);border-radius:14px 4px 14px 14px;padding:10px 14px;font-size:13px;line-height:1.5;white-space:pre-wrap}.tutor-error{align-self:flex-start;max-width:90%;border:1px solid var(--coral-500);background:#ff5a5a0f;color:var(--coral-500);border-radius:10px;padding:8px 12px;font-size:12px;line-height:1.4}.ai-avatar{width:28px;height:28px;border-radius:50%;background:var(--ink);color:var(--ink-on-dark);display:grid;place-items:center;font-family:var(--serif);font-style:italic;font-size:15px;flex-shrink:0;position:relative}.ai-avatar:after{content:"";position:absolute;top:-3px;right:-3px;bottom:-3px;left:-3px;border-radius:50%;border:1px solid var(--coral-500);opacity:.5}@keyframes shimmer{0%{background-position:-200% 0}to{background-position:200% 0}}.shimmer{background:linear-gradient(90deg,var(--bg-sunken) 0%,var(--bg-elev) 30%,var(--coral-100) 50%,var(--bg-elev) 70%,var(--bg-sunken) 100%);background-size:200% 100%;animation:shimmer 2.4s linear infinite;border-radius:6px}.diff-strike{text-decoration:line-through;text-decoration-color:var(--coral-500);text-decoration-thickness:2px;background:var(--coral-100);padding:1px 4px;border-radius:4px;color:var(--coral-700)}.diff-add{background:var(--green-100);padding:1px 4px;border-radius:4px;color:var(--green-700);font-weight:500;border-bottom:2px solid var(--green-500)}.err-underline{background:linear-gradient(transparent 60%,var(--coral-200) 60%);padding:0 2px;cursor:pointer;border-radius:2px}.input{height:40px;border-radius:var(--r-md);border:1px solid var(--line-2);background:var(--bg-card);padding:0 12px;font-family:inherit;font-size:14px;color:var(--ink);width:100%}.input:focus{outline:2px solid var(--coral-500);outline-offset:-1px}textarea.input{padding:12px;height:auto;line-height:1.55;resize:none}.seg{display:inline-flex;background:var(--bg-sunken);border-radius:999px;padding:3px;gap:2px}.seg-item{height:30px;padding:0 14px;border-radius:999px;font-size:12px;font-weight:500;color:var(--ink-3);display:inline-flex;align-items:center;cursor:pointer;border:none;background:transparent;font-family:inherit}.seg-item:hover:not(.active){background:var(--bg-elev);color:var(--ink-2)}.seg-item.active{background:var(--bg-card);color:var(--ink);box-shadow:var(--shadow-sm)}.scroll-y{overflow-y:auto}.scroll-y::-webkit-scrollbar{width:8px}.scroll-y::-webkit-scrollbar-thumb{background:var(--line-2);border-radius:4px}@keyframes spin{to{transform:rotate(360deg)}}.spinner{width:20px;height:20px;border:2px solid var(--line);border-top-color:var(--coral-500);border-radius:50%;animation:spin .6s linear infinite}