/* Theme palette only. Chapter and answer-state colours have independent owners. */
:root,html[data-theme="green"]{--theme-bg:#f8f6f0;--theme-surface:#fffefa;--theme-quiet:#eef3ed;--theme-hover:#e5eee5;--theme-ink:#20372e;--theme-muted:#526759;--theme-border:#c5d0c4;--theme-control:#7a9181;--theme-accent:#205f49;--theme-accent-hover:#174936;--theme-soft:#e4efe4;--theme-on-accent:#ffffff;--theme-hero:#143e36;--theme-hero-ink:#fbf6e9;--theme-hero-muted:#c6d5c9;--theme-gold:#edc877;--theme-gold-ink:#173b32;color-scheme:light}
html[data-theme="blue"]{--theme-bg:#f3f7fc;--theme-surface:#ffffff;--theme-quiet:#e9f0f9;--theme-hover:#e1ebf7;--theme-ink:#22364f;--theme-muted:#536780;--theme-border:#c4d1e2;--theme-control:#7c91ac;--theme-accent:#255e9c;--theme-accent-hover:#1d4b7e;--theme-soft:#e3edf9;--theme-on-accent:#ffffff;--theme-hero:#173552;--theme-hero-ink:#fbf6e9;--theme-hero-muted:#c6d5c9;--theme-gold:#edc877;--theme-gold-ink:#173b32;color-scheme:light}
html[data-theme="orange"]{--theme-bg:#fbf6f0;--theme-surface:#fffdf9;--theme-quiet:#f5eadc;--theme-hover:#f2e3cf;--theme-ink:#493429;--theme-muted:#725b4a;--theme-border:#dfcdb9;--theme-control:#aa8c70;--theme-accent:#985021;--theme-accent-hover:#7d3e17;--theme-soft:#f8e7d5;--theme-on-accent:#ffffff;--theme-hero:#503523;--theme-hero-ink:#fbf6e9;--theme-hero-muted:#c6d5c9;--theme-gold:#edc877;--theme-gold-ink:#173b32;color-scheme:light}
html[data-theme="purple"]{--theme-bg:#f8f5fc;--theme-surface:#fffdfd;--theme-quiet:#f0eaf8;--theme-hover:#e9def4;--theme-ink:#3c2e50;--theme-muted:#6e5c81;--theme-border:#d3c5e2;--theme-control:#9a82b2;--theme-accent:#734a96;--theme-accent-hover:#5e397e;--theme-soft:#efe5f8;--theme-on-accent:#ffffff;--theme-hero:#362542;--theme-hero-ink:#fbf6e9;--theme-hero-muted:#c6d5c9;--theme-gold:#edc877;--theme-gold-ink:#173b32;color-scheme:light}
html[data-theme="night"]{--theme-bg:#101519;--theme-surface:#192126;--theme-quiet:#202b30;--theme-hover:#29383e;--theme-ink:#e4ece9;--theme-muted:#adc0b9;--theme-border:#3d514b;--theme-control:#66857a;--theme-accent:#a0d9bd;--theme-accent-hover:#bee9d2;--theme-soft:#233c32;--theme-on-accent:#10291d;--theme-hero:#172c25;--theme-hero-ink:#e4ece9;--theme-hero-muted:#b8cdc2;--theme-gold:#edc877;--theme-gold-ink:#173b32;color-scheme:dark}
:root{--state-success:#21633f;--state-success-bg:#e6f4eb;--state-success-solid:#276444;--state-success-border:#83ae92;--state-danger:#983f39;--state-danger-bg:#fcecea;--state-danger-solid:#a54b43;--state-danger-border:#c98b83;--state-warning:#80521e;--state-warning-bg:#fff0d5;--state-warning-border:#cead70;}
html[data-theme="night"]{--state-success:#afe5bd;--state-success-bg:#203b2b;--state-success-solid:#afe5bd;--state-success-border:#548867;--state-danger:#ffb8af;--state-danger-bg:#442a29;--state-danger-solid:#ffb8af;--state-danger-border:#a26b65;--state-warning:#efd09b;--state-warning-bg:#3b3021;--state-warning-border:#8e7345;}
:root{--ink:var(--theme-ink);--muted:var(--theme-muted);--primary:var(--theme-accent);--primary-dark:var(--theme-accent);--light-green:var(--theme-soft);--pale:var(--theme-bg);--surface:var(--theme-surface);--line:var(--theme-border);--exam-muted:var(--theme-muted);--exam-selected:var(--theme-soft);--exam-error:var(--state-danger);--exam-warm:var(--state-warning-bg);--brand-forest:var(--theme-ink);--brand-teal:var(--theme-accent);--brand-gold:var(--theme-gold);--brand-cream:var(--theme-surface);accent-color:var(--theme-accent)}
:root{--state-on-solid:#ffffff}html[data-theme="night"]{--state-on-solid:#10291d}

:root{--print-paper:#ffffff;--print-ink:#182f2b}