/* Learning Center — shared base.
   Near-neutral ink palette: crisp hairlines, calm depth, one blue accent.
   Page styles (guide.css / dashboard.css) build on these tokens only. */
:root{color-scheme:light;
  --bg:#f7f8fa; --panel:#fff; --panel2:#eef1f5; --text:#0e1116; --muted:#5b6472;
  --border:#e3e7ee; --border-strong:#d3d9e3; --accent:#1d4ed8; --link:#1d4ed8;
  --accent-soft:#eef2ff; --code:#f2f4f7; --code-text:#1b2430; --ok:#0f7a4f;
  --r-xs:5px; --r-sm:7px; --r-md:10px;
}
[data-theme="dark"]{color-scheme:dark;
  --bg:#0b0d11; --panel:#14171d; --panel2:#1b1f27; --text:#e7eaf0; --muted:#9aa4b2;
  --border:#252a34; --border-strong:#333a47; --accent:#4d8dff; --link:#7caeff;
  --accent-soft:#17233b; --code:#11141a; --code-text:#dde3ec; --ok:#4ade80;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--text);font:16.5px/1.7 -apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;-webkit-font-smoothing:antialiased}
a{color:var(--link);text-underline-offset:2px}

/* ---- browser surfaces carry the palette ---- */
::selection{background:var(--accent);color:#fff}
[data-theme="dark"] ::selection{background:var(--accent);color:#0b0d11}
:focus-visible{outline:2px solid var(--accent);outline-offset:2px}
*{caret-color:var(--accent)}
*::-webkit-scrollbar{width:11px;height:11px}
*::-webkit-scrollbar-thumb{background:var(--border-strong);border:3px solid var(--bg);border-radius:8px}
*::-webkit-scrollbar-thumb:hover{background:var(--muted)}
*::-webkit-scrollbar-track{background:transparent}
*{scrollbar-width:thin;scrollbar-color:var(--border-strong) transparent}

.icon{width:16px;height:16px;flex:0 0 auto;display:block}
#themeToggle .icon-sun{display:none}
[data-theme="dark"] #themeToggle .icon-moon{display:none}
[data-theme="dark"] #themeToggle .icon-sun{display:block}

/* ---- topbar ---- */
.topbar{position:sticky;top:0;z-index:50;display:flex;gap:12px;align-items:center;padding:12px 20px;background:var(--panel);border-bottom:1px solid var(--border);flex-wrap:wrap}
.brand{font-weight:650;font-size:14.5px;flex:1;min-width:0;letter-spacing:-.1px}
.brand small{display:block;font-weight:400;color:var(--muted);font-size:12.5px;letter-spacing:0;margin-top:1px}
#themeToggle{display:inline-flex;align-items:center;gap:7px;border:1px solid var(--border);background:var(--panel2);color:var(--text);border-radius:var(--r-sm);padding:7px 13px;cursor:pointer;font:inherit;font-size:13.5px;font-weight:600;white-space:nowrap;transition:color .15s,border-color .15s,background .15s}
#themeToggle:hover{border-color:var(--accent);color:var(--accent);background:var(--accent-soft)}

.cat{display:inline-block;font-size:11px;font-weight:700;letter-spacing:.06em;text-transform:uppercase;padding:3px 9px;border-radius:var(--r-sm);background:var(--accent-soft);color:var(--accent)}

@media (prefers-reduced-motion:reduce){*{animation:none !important;transition:none !important}}