@import url('https://fonts.googleapis.com/css2?family=DM+Sans:wght@400;500;600;700&family=Manrope:wght@400;500;600;700;800&display=swap');
:root{--accent:#237a23;--ink:#1b271c;--muted:#657064;--line:#e0e7de;--paper:#f6f8f5;--surface:#fff;--selected:#e7f3e5;--hover:#edf4eb;--callout:#edf6ea;--example:#f5f8ec;--example-ink:#526925;--success:#edf6ed;--error:#fff1e6;--completion:#eaf5e7;--completion-ink:#386334;--button:#237a23}*{box-sizing:border-box}body{margin:0;background:var(--paper);color:var(--ink);font:16px/1.6 'DM Sans',sans-serif}button,a,input{font:inherit}button,a{touch-action:manipulation}button{cursor:pointer}button:focus-visible,a:focus-visible,input:focus-visible{outline:3px solid #e78118;outline-offset:4px}header{height:92px;background:var(--surface);border-bottom:1px solid var(--line);display:flex;align-items:center;justify-content:space-between;padding:0 5%}.brand{font:800 34px Manrope,sans-serif;text-decoration:none;color:var(--ink);letter-spacing:-2px;display:flex;align-items:center;gap:10px}.brand-dot{color:var(--accent);margin-left:-10px}.mark{background:var(--accent);border-radius:12px;color:#fff;width:37px;height:37px;line-height:30px;text-align:center;font-size:46px;margin-right:3px}.header-label,.eyebrow{font-size:12px;letter-spacing:1.8px;font-weight:700}.header-label{color:var(--muted)}.badge,.tag{font-size:13px;border:1px solid var(--line);padding:7px 13px;border-radius:30px;white-space:nowrap}.shell{max-width:1500px;margin:auto;display:grid;grid-template-columns:290px minmax(0,1fr);gap:55px;padding:48px 5%}aside h1{font:800 32px/1.22 Manrope,sans-serif;letter-spacing:-1px;margin:22px 0 16px}.eyebrow{color:var(--accent);margin:0 0 10px}.intro{color:var(--muted);font-size:15px}nav{margin-top:38px;display:grid;gap:7px}.nav-item{border:0;border-radius:9px;background:transparent;text-align:left;padding:13px 15px;display:flex;gap:15px;color:var(--muted);font-size:14px}.nav-item.selected{background:var(--selected);color:var(--accent);font-weight:700}.nav-item:hover{background:var(--hover)}.side-note{border-top:1px solid var(--line);margin-top:45px;padding-top:24px;font-size:14px}.side-note p{color:var(--muted)}h2{font:800 30px/1.3 Manrope,sans-serif;letter-spacing:-.8px;margin:0}h3{font-family:Manrope,sans-serif}.page-heading{display:flex;align-items:center;justify-content:space-between;gap:15px;margin-bottom:26px}.welcome{border-radius:16px;background:#237a23;color:white;padding:34px;display:flex;justify-content:space-between;overflow:hidden;position:relative}.welcome .eyebrow{color:#d0ebca}.welcome h3{font-size:29px;line-height:1.35;font-weight:600;letter-spacing:-.6px;margin:16px 0}.welcome p{color:#dcefd8;font-size:15px}.primary,.secondary{border:0;border-radius:8px;padding:11px 20px;font-weight:700;font-size:14px;display:inline-block;text-decoration:none}.primary{background:var(--button);color:white}.welcome .primary{background:white;color:#237a23;margin-top:12px}.secondary{border:1px solid var(--line);background:var(--surface);color:var(--ink)}.primary:hover{filter:brightness(.94)}.math-art{width:230px;min-width:190px;position:relative;margin-left:20px;background-image:linear-gradient(#ffffff10 1px,transparent 1px),linear-gradient(90deg,#ffffff10 1px,transparent 1px);background-size:26px 26px}.axis{position:absolute;background:#8bce80}.x{width:85%;height:1px;top:60%;left:5%}.y{height:85%;width:1px;left:40%;top:8%}.circle{position:absolute;border:2px solid #9ed692;width:140px;height:140px;border-radius:50%;top:20%;left:15%}.label-one{position:absolute;top:30%;left:30%;font-size:27px;white-space:nowrap;transform:rotate(-8deg)}.label-two{position:absolute;bottom:8%;left:45%;font-family:Georgia,serif;font-style:italic;font-size:24px;color:#bee3b7}.point{position:absolute;width:13px;height:13px;border-radius:50%;background:#d1f477;left:38%;top:58%}.section-heading{display:flex;align-items:center;justify-content:space-between;gap:16px;margin:26px 0 18px}.section-heading h3{font-size:18px;margin:0}.section-heading span{font-size:13px;color:var(--muted)}.cards{display:grid;grid-template-columns:1fr 1fr;gap:16px}.module{background:var(--surface);border:1px solid var(--line);border-radius:12px;padding:24px;position:relative;transition:transform .15s,border-color .15s}.module:hover{border-color:#75b96d;transform:translateY(-2px)}.module-number{font-size:12px;font-weight:700;letter-spacing:1px;color:var(--muted)}.module h3{font-size:20px;line-height:1.3;margin:16px 0 8px}.module p{font-size:14px;line-height:1.6;color:var(--muted);margin:0 0 20px}.module-footer{display:flex;justify-content:space-between;align-items:center;gap:8px;font-size:12px;color:var(--muted)}.module button{padding:0;background:none;border:0;color:var(--accent);font-size:14px;font-weight:700}.symbol{position:absolute;right:23px;top:17px;font:24px Georgia,serif;color:var(--accent)}.panel{background:var(--surface);border:1px solid var(--line);border-radius:14px;padding:30px;margin-bottom:20px}.panel h3{margin-top:0;font-size:23px}.panel p:last-child{margin-bottom:0}.callout{background:var(--callout);border-left:3px solid var(--accent);padding:18px 22px;margin:22px 0;border-radius:0 8px 8px 0}.example{background:var(--example);border-radius:10px;padding:22px;margin:20px 0}.example b{color:var(--example-ink)}.steps{padding-left:22px}.steps li{padding:5px 0}.formula{font:27px Georgia,serif;letter-spacing:.5px;padding:16px 0;color:var(--accent)}.actions{display:flex;gap:12px;flex-wrap:wrap;margin-top:23px}.back{border:0;background:none;color:var(--muted);padding:0;margin-bottom:20px;font-size:14px}.quiz-options{display:grid;gap:10px;margin:20px 0}.option{display:flex;gap:12px;align-items:center;border:1px solid var(--line);padding:13px 16px;border-radius:8px;cursor:pointer}.option:has(input:checked){border-color:var(--accent);background:var(--callout)}.option input{accent-color:var(--accent);width:18px;height:18px}.feedback{padding:18px;background:var(--success);border-radius:9px;margin:16px 0}.feedback.error{background:var(--error)}.muted{color:var(--muted)}.small{font-size:14px}.score{font:800 56px Manrope,sans-serif;color:var(--accent)}progress{width:100%;height:9px;accent-color:var(--accent);border:0;border-radius:10px;overflow:hidden}.progress-row{display:flex;justify-content:space-between;font-size:14px;margin-bottom:6px}.result-row{padding:18px 0;border-bottom:1px solid var(--line)}.result-row:last-child{border:0}.result-row p{margin:6px 0;font-size:14px}.completed{color:#39743e}.notice{font-size:13px;color:var(--muted);margin-top:20px}.quiz-top{display:flex;justify-content:space-between;color:var(--muted);font-size:14px;margin-bottom:20px}button:disabled{opacity:.5;cursor:default}.practice input{width:140px;border:1px solid #a8b3a5;border-radius:7px;padding:10px}.practice label{display:block;margin-bottom:12px}.empty{text-align:center;padding:24px}.completion{display:inline-block;background:var(--completion);color:var(--completion-ink);border-radius:20px;font-size:12px;padding:3px 10px}@media(min-width:1450px){.shell{gap:75px}}@media(max-width:1000px){.shell{grid-template-columns:220px minmax(0,1fr);gap:25px;padding:35px 4%}.math-art{display:none}.welcome h3{font-size:27px}.header-label{display:none}.module{padding:20px}.page-heading{align-items:flex-start}.tag{display:none}}@media(max-width:700px){header{height:74px;padding:0 6%}.brand{font-size:29px}.badge{font-size:12px}.shell{display:block;padding:25px 6%}aside h1,aside .intro,aside>.eyebrow,.side-note{display:none}nav{display:flex;gap:5px;overflow:auto;margin:0 0 28px}.nav-item{white-space:nowrap;padding:11px 12px}.nav-item>span{font-size:14px}.nav-item{font-size:0}.cards{grid-template-columns:1fr}.welcome{padding:26px}.welcome h3{font-size:26px}.welcome br{display:none}h2{font-size:27px}.section-heading{align-items:flex-start;flex-direction:column;gap:4px}.panel{padding:23px}.page-heading{margin-bottom:20px}.formula{font-size:24px;overflow-wrap:anywhere}}

:root{color-scheme:light}html[data-theme="dark"]{color-scheme:dark;--accent:#75d66a;--button:#237a23;--ink:#f2f2f2;--muted:#b5b5b5;--line:#333333;--paper:#000000;--surface:#111111;--selected:#242424;--hover:#202020;--callout:#1c1c1c;--example:#181c16;--example-ink:#c0df9f;--success:#14251c;--error:#2b1d16;--completion:#1b2b1c;--completion-ink:#bee2b3}html[data-theme="dark"] .mark{background:#237a23}html[data-theme="dark"] .module:hover{border-color:#75d66a}html[data-theme="dark"] .completed{color:#bee2b3}.practice input{background:var(--surface);color:var(--ink)}.practice input::placeholder{color:var(--muted)}.header-actions{display:flex;align-items:center;gap:15px}.theme-toggle{display:flex;align-items:center;gap:8px;min-height:44px;padding:8px 13px;border:1px solid var(--line);border-radius:9px;background:var(--surface);color:var(--ink);font-size:14px;font-weight:600;white-space:nowrap}.theme-toggle:hover{background:var(--hover)}#theme-icon{font-size:22px;line-height:1}.theme-toggle[aria-pressed="true"]{border-color:var(--accent);color:var(--accent)}@media(max-width:1100px){.header-label{display:none}}@media(max-width:700px){.header-actions .badge{display:none}.header-actions{gap:0}.theme-toggle{font-size:13px;padding:8px 10px}}

html[data-theme="dark"] .welcome{background:#111111;border:1px solid #333333}html[data-theme="dark"] .welcome p{color:#c6c6c6}html[data-theme="dark"] .welcome .primary{background:#237a23;color:#fff}