:root{
  --accent:#0c6166;--on-accent:#fff;--page:#f3f6f5;--paper:#fff;--ink:#1b3440;--muted:#4b626a;
  --border:#d9e4e2;--border-strong:#8dadab;--wash:#eaf3f1;--wash-border:#cfe1dd;--wash-ink:#143d43;--wash-muted:#405d62;
  --quiet-border:#bfd0cf;--nav-border:#d2dfdd;--panel-border:#d6e1df;--shadow:#1d4c4b0d;
  --header-muted:#b8e7dd;--header-copy:#e4f3ef;--focus:#ec9c33;
  --success:#187351;--error:#ac442d;--success-bg:#effaf4;--error-bg:#fff4f0;
  --soft:#f5f8f7;--soft-border:#b8cbc8;--input-border:#9db7b5;--selected:#e9f5f2;
  --secondary:#526870;--body-muted:#4d646b;--hint:#4c636b;--footer:#586d73;--strong:#173e48;
  --placeholder:#697d83;--verb:#667981;--feedback:#34545b;--hint-ink:#405c63;
  --line-alt:#b9cbd4;--line:#d5e1df;--line-blue:#cfdae0;--link-blue:#075da8;
  --blue-wash:#dceaf5;--blue-border:#c8d9de;--heading-alt:#153343;--paper-alt:#f8fafb;
  --highlight:#e1f1ed;--highlight-ink:#07545a;--pale:#f1f7f6;--deep:#152f3e;
  --accent-light:#578c9f;--warning-ink:#7b4a08;--warning-bg:#fff1d6;--warning-pale:#fff6e8;--warning-border:#c67a24;
  --mint:#edf6f4;--mint-border:#d3ebe5;--accent-deep:#08494d;--hover:#f8fcfb;
}
:root[data-theme="ocean"]{--accent:#205aa1;--wash:#e8f0fb;--wash-border:#cbdcf4;--wash-ink:#183f72;--wash-muted:#344e70;--selected:#e8f0fb;--highlight:#e1ecfb;--highlight-ink:#174e91;--header-muted:#d3e4ff;--header-copy:#eef4ff;--accent-deep:#184879;--hover:#f6faff;--focus:#bb6b15}
:root[data-theme="plum"]{--accent:#6a3a83;--wash:#f4edf8;--wash-border:#e3d4eb;--wash-ink:#4b2a60;--wash-muted:#594667;--selected:#f3eafa;--highlight:#efe4f6;--highlight-ink:#613276;--header-muted:#efdbf5;--header-copy:#f8effb;--accent-deep:#552c69;--hover:#fdf9ff;--focus:#b35e19}
:root[data-theme="dark"]{
  color-scheme:dark;--accent:#74cfd0;--page:#111b22;--paper:#1c2b33;--ink:#e9f2f4;--muted:#c0d0d5;
  --border:#3c545d;--border-strong:#64848e;--wash:#20373e;--wash-border:#42666a;--wash-ink:#ebf9f7;--wash-muted:#c9deda;
  --quiet-border:#49636b;--nav-border:#49636b;--panel-border:#42606a;--shadow:#0005;
  --header-muted:#c1efea;--header-copy:#e6f6f4;--focus:#ffc46c;
  --success:#77d4a5;--error:#ffae9d;--success-bg:#1e3e34;--error-bg:#442b2b;
  --soft:#21343d;--soft-border:#54727a;--input-border:#76939a;--selected:#294950;
  --secondary:#c0d1d6;--body-muted:#c5d5d9;--hint:#c4d4d8;--footer:#bacdd2;--strong:#ecf9f8;
  --placeholder:#a9c1c7;--verb:#b8cbd0;--feedback:#d6e9eb;--hint-ink:#c2dfe0;
  --line-alt:#4c6872;--line:#47616a;--line-blue:#506b75;--link-blue:#91c9ff;
  --blue-wash:#233c53;--blue-border:#4e718a;--heading-alt:#e7f4f7;--paper-alt:#20323b;
  --highlight:#29504d;--highlight-ink:#d9f8eb;--pale:#213b3c;--deep:#f0f8fa;
  --accent-light:#9ddadd;--warning-ink:#ffe0a0;--warning-bg:#483821;--warning-pale:#3a3024;--warning-border:#edbd67;
  --mint:#28413e;--mint-border:#4d746c;--accent-deep:#ace6e3;--hover:#263e47;
}
:root[data-theme="dark"] header{background:#123f47;color:#fff}
:root[data-theme="dark"] .lesson-nav a[aria-current="page"],:root[data-theme="dark"] .primary{background:#286a70;color:#fff}
:root[data-theme="dark"] .nav-divider span{background:var(--page)}

.site-title{font-size:1.55rem;line-height:1.25}
@media(max-width:520px){.site-title{font-size:1.32rem}}