/* Four seasonal palettes reuse the homepage chapter fallback colors. */
:root{--nb-bg:#06040a;--nb-paper:#201b18;--nb-ink:#f5f2eb;--nb-muted:#c6bfb6;--nb-line:#625347;--nb-accent:#ebc28a;--nb-accent-soft:#3b2d20;--nb-amber:#f1b186;--nb-amber-soft:#422d23;--nb-chat:#15110f;--nb-bubble:#25201b;--nb-glow:#2a1c0e;--nb-serif:var(--serif,'Instrument Serif',"Songti SC",serif);--nb-ui:var(--ui,system-ui,-apple-system,"PingFang SC",sans-serif)}
:root[data-nb-theme="winter"]{--nb-bg:#04060a;--nb-paper:#19232f;--nb-muted:#bdcad9;--nb-line:#4e6279;--nb-accent:#afcfe9;--nb-accent-soft:#243b50;--nb-amber:#edbc88;--nb-amber-soft:#3e3025;--nb-chat:#0e1721;--nb-bubble:#1d2a38;--nb-glow:#141f2e}
:root[data-nb-theme="summer"]{--nb-bg:#04080a;--nb-paper:#172922;--nb-muted:#bdd0c5;--nb-line:#48695b;--nb-accent:#a8d5b9;--nb-accent-soft:#244334;--nb-amber:#efc383;--nb-amber-soft:#3e3324;--nb-chat:#0c1913;--nb-bubble:#1b3026;--nb-glow:#12251f}
:root[data-nb-theme="spring"]{--nb-bg:#05070c;--nb-paper:#202538;--nb-muted:#c5c9de;--nb-line:#626781;--nb-accent:#c6bfea;--nb-accent-soft:#34314e;--nb-amber:#f1b897;--nb-amber-soft:#432e29;--nb-chat:#151827;--nb-bubble:#292d42;--nb-glow:#1b2436}