/* Shared by index.html (trace) and arch.html (architecture): palette + page frame.
   Page-specific styles stay in each page's <style>. */
:root{--bg:#0f1419;--panel:#161d26;--line:#243040;--ink:#dfe6ee;--mut:#8aa0b6;--act:#2b9cff;--hl:#ffd34d}
*{box-sizing:border-box}
body{font:14px/1.4 system-ui,sans-serif;margin:0;background:var(--bg);color:var(--ink);
     height:100vh;display:flex;flex-direction:column;overflow:hidden}
a{color:var(--mut);text-decoration:none}
header{padding:12px 20px;background:var(--panel);border-bottom:1px solid var(--line);
       display:flex;align-items:center;gap:14px;flex:0 0 auto}
h1{font-size:16px;margin:0;font-weight:600}