:root{--field-rgb:128,223,208;--field-grid:#80b4b00a;--field-axis:#6f8f9624;--field-label:#5f7f8a;--topbar:#0b1016eb}
    .header-actions{display:flex;align-items:center;gap:10px;flex-shrink:0}.theme-toggle{width:37px;height:37px;display:grid;place-items:center;flex-shrink:0;border:1px solid var(--line-strong);background:var(--panel);border-radius:5px;color:var(--muted)}.theme-toggle:hover{color:var(--accent);border-color:var(--accent)}.theme-toggle svg{width:18px;height:18px;grid-area:1/1;fill:none;stroke:currentColor;stroke-width:1.5;stroke-linecap:round;stroke-linejoin:round}.theme-toggle .moon{display:none}.mobile-nav{display:none}.topbar{background:var(--topbar)}.angle-control input{height:24px}.route p,.course-desc,.foundation>p{overflow-wrap:anywhere}.search-input{margin-top:9px}.dialog-content{scrollbar-gutter:stable}.term-button{min-height:44px}.close-dialog{width:40px;height:40px}
    html[data-theme="light"]{--bg:#f5f8fa;--panel:#fff;--panel2:#eaf1f4;--text:#172f3c;--muted:#516b79;--dim:#607887;--accent:#087f73;--line:#17394a16;--line-strong:#17394a30;--field-rgb:8,127,115;--field-grid:#23596509;--field-axis:#2359652a;--field-label:#527987;--topbar:#f5f8faed;color-scheme:light}
    html[data-theme="dark"]{color-scheme:dark}
    [data-theme="light"] .theme-toggle .sun{display:none}[data-theme="light"] .theme-toggle .moon{display:block}
    [data-theme="light"] .sidebar{background:#edf3f6}[data-theme="light"] .side-nav a:hover{background:#0c6b6a07;color:var(--text)}[data-theme="light"] .side-nav a.active{background:#087f730d}[data-theme="light"] .mini-outline a{color:#4e6877}[data-theme="light"] .mini-outline a:hover{color:var(--accent)}[data-theme="light"] .mini-outline span{color:#66838e}[data-theme="light"] .sidebar-foot a{color:var(--accent)}[data-theme="light"] .breadcrumb span{color:#8a9da6}
    [data-theme="light"] .search-button{background:#fff9}[data-theme="light"] .button{color:#fff}[data-theme="light"] .button:hover{background:#066e64}[data-theme="light"] .button.secondary{background:#ffffff40;color:var(--text)}[data-theme="light"] .button.secondary:hover{background:#087f7308}[data-theme="light"] .field-figure{background:radial-gradient(ellipse at 50% 50%,#90d3c82b,transparent 68%)}[data-theme="light"] .field-formula{color:#35756d;opacity:.9}
    [data-theme="light"] .route.selected{background:linear-gradient(110deg,#e5f4ef,#f5faf9);border-color:#087f7370}[data-theme="light"] .route:hover{border-color:#087f7355}[data-theme="light"] .radio-dot{border-color:#72918f}[data-theme="light"] .route-feedback strong{color:var(--text)}[data-theme="light"] .course-row:hover{background:#087f7305}[data-theme="light"] .course-tag.sample{background:#087f7307;border-color:#087f7325}
    [data-theme="light"] .foundation{background:linear-gradient(150deg,#eaf4f3,#fff 75%)}[data-theme="light"] .foundation-icon{border-color:#087f7330}[data-theme="light"] .term-button{background:#ffffff9c;color:#365c67}[data-theme="light"] .term-button:hover{border-color:#087f7350;color:var(--accent)}[data-theme="light"] .sample-strip{background:linear-gradient(100deg,#e7f2ef,#ffffff60 85%)}
    [data-theme="light"] dialog{background:#fbfdfe;border-color:#17394a30;box-shadow:0 24px 100px #17394a30}[data-theme="light"] dialog::backdrop{background:#182e466b}[data-theme="light"] .dialog-top{background:#fbfdfe}[data-theme="light"] .close-dialog{background:#17394a06}[data-theme="light"] .close-dialog:hover{background:#17394a10;color:var(--text)}[data-theme="light"] .dialog-content p,[data-theme="light"] .dialog-content li{color:#415d6c}[data-theme="light"] .dialog-content .lead{color:#233f4d}[data-theme="light"] .formula{background:#087f7307;color:#175b52}[data-theme="light"] .callout{background:#17394a03}[data-theme="light"] .sample-question{border-color:#087f733b}[data-theme="light"] .answer-options button{background:#17394a03}[data-theme="light"] .answer-options button:hover{border-color:var(--accent)}[data-theme="light"] .reading-switch button.selected{border-color:#087f7355;background:#087f7309}[data-theme="light"] .search-input{background:#fff}[data-theme="light"] .inline-term{border-color:#087f7360}[data-theme="light"] ::selection{background:#087f7322;color:#173d36}
    @media(max-width:920px){.topbar{gap:18px}.mobile-nav{position:sticky;top:77px;z-index:9;display:flex;justify-content:space-between;gap:8px;padding:9px 30px;background:var(--topbar);border-bottom:1px solid var(--line);backdrop-filter:blur(16px)}.mobile-nav a{font-size:13px;color:var(--muted);min-height:36px;display:flex;align-items:center;padding:0 9px;border-radius:4px}.mobile-nav a:first-child{color:var(--accent);background:#80dfd00b}.mobile-nav a:hover{color:var(--accent)}html{scroll-padding-top:143px}section{scroll-margin-top:143px}}
    @media(max-width:640px){.topbar{gap:12px}.header-actions{gap:8px}.theme-toggle,.search-button{width:40px;height:40px}.search-button{justify-content:center;padding:9px}.mobile-nav{top:65px;padding:6px 17px;gap:3px}.mobile-nav a{font-size:12px;min-height:38px;padding:0 7px}.breadcrumb{white-space:nowrap}.button{min-height:44px}.quiet-link{font-size:11px}.hero h1{font-size:clamp(29px,8.7vw,37px)}.hero-description{line-height:1.95}.route{min-height:108px}.route p{font-size:13px}.route-bottom{font-size:11px}.course-row{gap:9px;min-height:78px}.course-name{font-size:15px}.course-desc{font-size:12px;line-height:1.8;margin-top:4px}.course-footer{gap:12px;align-items:flex-start}.course-footer span:last-child{white-space:nowrap}.figure-bottom{gap:9px}.figure-bottom>span{max-width:48%}.angle-control{gap:6px}.angle-control input{width:72px;min-height:32px}.foundation h2{font-size:17px;line-height:1.6}.foundation-icon{flex-shrink:0;margin-left:8px}.foundation-footer,.reading-note{font-size:12px}.sample-strip small{font-size:11px}.dialog-top{padding:11px 17px}.dialog-content{padding:21px}.dialog-content h2{font-size:23px}.dialog-content p,.dialog-content li{font-size:16px;line-height:1.95}.reading-switch{gap:6px}.reading-switch button{min-height:44px;font-size:13px;padding:8px 11px}.answer-options button{min-height:44px;font-size:14px}.back-button{min-height:40px;font-size:14px}.search-result{min-height:48px;font-size:15px}.modal-footer-note{font-size:13px!important}.formula{font-size:18px;line-height:1.95;overflow-wrap:normal}.formula small{font-size:13px}.footer{line-height:1.9}.dialog-kicker{font-size:10px;line-height:1.8}html{scroll-padding-top:129px}section{scroll-margin-top:129px}}
    @media(max-width:360px){.content{padding-left:16px;padding-right:16px}.topbar{padding-left:16px;padding-right:16px}.mobile-nav{padding-left:10px;padding-right:10px}.breadcrumb{font-size:11px}.header-actions{gap:5px}.hero-actions{gap:8px}.hero-actions .button{font-size:12px;padding:10px 13px;gap:10px}.figure-bottom>span{font-size:10px}.term-grid{gap:6px}.term-button{padding:9px 8px;font-size:13px}.section-heading{gap:8px}.section-title{gap:7px}h2{font-size:17px}.course-row{grid-template-columns:23px minmax(0,1fr) 14px}.course-desc{font-size:11px}.reading-switch button{padding:8px;font-size:12px}}
    @media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}.reveal{animation:none}*{transition:none!important}}