/* Reading tracker (assets/js/reading-tracker.js) — flat design tokens
   (assets/css/flat-tokens.css), with literals as fallbacks so the old A/B arm,
   which loads other stylesheets, renders it the same. */

.rs { --rs-ink: var(--flat-ink, #0a0a0a); --rs-paper: var(--flat-paper, #fff);
      --rs-hair: var(--flat-hair, #e6e6e6); --rs-blue: var(--flat-blue, #1a3aff);
      --rs-green: var(--flat-green, #0f7a4a); --rs-dim: var(--flat-dim, #6b7280);
      font-family: var(--flat-font, 'Be Vietnam Pro', system-ui, sans-serif); margin: 0 0 18px; }

/* The bar stays on screen while the roadmap is being read. */
.rs-bar { position: sticky; bottom: 12px; z-index: 20; display: flex; flex-wrap: wrap; align-items: center;
          gap: 8px 14px; padding: 10px 14px; background: var(--rs-paper); color: var(--rs-ink);
          border: 2px solid var(--rs-ink); font-size: 13px; line-height: 1.4; }
.rs-bar.is-done { border-color: var(--rs-green); }
.rs-bar-t b { font-weight: 800; }
.rs-track { flex: 1 1 120px; height: 6px; background: var(--rs-hair); overflow: hidden; min-width: 90px; }
.rs-track i { display: block; height: 100%; width: 0; background: var(--rs-blue); transition: width .4s; }
.rs-bar.is-done .rs-track i { background: var(--rs-green); }
.rs-how { flex: 1 0 100%; font-size: 12px; color: var(--rs-dim); }
.rs-how summary { cursor: pointer; font-weight: 600; min-height: 24px; }
.rs-how p { margin: 6px 0 0; line-height: 1.55; }
.rs-done { display: inline-flex; align-items: center; gap: 6px; font-weight: 800; color: var(--rs-green); }
.rs-done[hidden], .rs-guest[hidden] { display: none; }
.rs-guest { flex: 1 0 100%; margin: 0; padding: 8px 10px; background: #fff7f2; border: 1px solid #f5c8b3;
            font-size: 13px; color: var(--rs-ink); }
.rs-guest a { color: var(--rs-blue); font-weight: 700; }

/* A ring before each heading, filling as the section is read. */
.rs-mark { --rs-p: 0; display: inline-block; width: 14px; height: 14px; margin-right: 8px; vertical-align: -1px;
           border-radius: 50%; flex: 0 0 auto;
           background: conic-gradient(var(--flat-blue, #1a3aff) calc(var(--rs-p) * 360deg), var(--flat-hair, #e6e6e6) 0);
           -webkit-mask: radial-gradient(circle, transparent 3.5px, #000 4px); mask: radial-gradient(circle, transparent 3.5px, #000 4px); }
.rs-mark.is-done { -webkit-mask: none; mask: none; background: var(--flat-green, #0f7a4a); position: relative; }
.rs-mark.is-done::after { content: ''; position: absolute; left: 4.5px; top: 2px; width: 4px; height: 7px;
                          border: solid #fff; border-width: 0 2px 2px 0; transform: rotate(45deg); }
.sk-toc li.is-read > a { color: var(--flat-green, #0f7a4a); }
.sk-toc li.is-read > a::before { content: ''; display: inline-block; width: 6px; height: 10px; margin-right: 7px;
                                 border: solid currentColor; border-width: 0 2px 2px 0; transform: rotate(45deg) translateY(-2px); }

@media (prefers-reduced-motion: reduce) { .rs-track i { transition: none; } }
@media (max-width: 560px) { .rs-bar { bottom: 8px; padding: 8px 10px; } }
.rs-left[hidden] { display: none; }
.rs-how summary:focus-visible { outline: 3px solid var(--flat-blue, #1a3aff); outline-offset: 2px; }