:root {--yellow:#FCD34D;--yellow-accent:#FBBF24;--blue:#BFDBFE;--blue-accent:#60A5FA;--bg:#f8fafc;--bg-alt:#eef6ff;--dark:#0f172a;--radius:10px;--transition:150ms cubic-bezier(.4,0,.2,1);--sidebar-width:270px;font-family:'Inter',system-ui,sans-serif;}
*{box-sizing:border-box;margin:0;padding:0;}body{background:var(--bg);color:var(--dark);line-height:1.55;-webkit-font-smoothing:antialiased;}
a,h1,h2,h3,h4,h5,h6,p{margin:0;padding:0;}
/* Global default typography so semantic tags render styled without extra classes */
h1{font-size:2.125rem;line-height:1.15;font-weight:600;letter-spacing:-.5px;margin:0 0 1rem;}
h2{font-size:1.35rem;line-height:1.25;font-weight:600;margin:2.25rem 0 1rem;padding-left:.75rem;border-left:4px solid var(--yellow);}
h3{font-size:1.15rem;line-height:1.35;font-weight:600;margin:1.75rem 0 .75rem;color:var(--blue-accent);}
p{margin:0 0 1rem;line-height:1.6;}
a{color:#0c4a6e;text-decoration:none;transition:color var(--transition);}a:hover,a:focus{color:#172554;text-decoration:underline;}
/* (Anchor styles overridden above for underline on hover) */
img{max-width:100%;display:block;border-radius:var(--radius);}
.layout{display:flex;min-height:100vh;}
.sidebar{width:var(--sidebar-width);background:linear-gradient(180deg,var(--yellow) 0%,var(--blue) 100%);padding:1.25rem;display:flex;flex-direction:column;gap:1.5rem;position:sticky;top:0;max-height:100vh;overflow:auto;box-shadow:0 0 0 1px rgba(0,0,0,.05),0 4px 20px -2px rgba(0,0,0,.15);} 
.brand{font-size:1.35rem;font-weight:700;display:flex;align-items:center;gap:.5rem;}
.brand-logo{width:34px;height:34px;display:inline-grid;grid-template-columns:repeat(3,1fr);grid-template-rows:repeat(3,1fr);gap:2px;padding:4px;border-radius:8px;background:linear-gradient(145deg,#0ea5e9,#0369a1);box-shadow:0 2px 4px rgba(0,0,0,.25),inset 0 1px 2px rgba(255,255,255,.35);position:relative;}
.brand-logo span{background:rgba(255,255,255,.82);border-radius:2px;box-shadow:inset 0 0 0 1px rgba(0,0,0,.06);} 
.brand-logo:after{content:"";position:absolute;inset:0;border-radius:8px;background:radial-gradient(circle at 75% 20%,rgba(255,255,255,.55),transparent 60%);} 
.brand-text{line-height:1;display:flex;flex-direction:column;font-size:1.05rem;font-weight:700;letter-spacing:.5px;}
.brand-text small{font-size:.55rem;font-weight:600;letter-spacing:1.2px;opacity:.75;margin-top:2px;text-transform:uppercase;}
.nav-section h4{font-size:.75rem;letter-spacing:.08em;font-weight:600;text-transform:uppercase;margin-bottom:.35rem;opacity:.8;}
nav ul{list-style:none;display:flex;flex-direction:column;gap:.25rem;}
nav li a{display:flex;align-items:center;gap:.5rem;font-weight:500;padding:.55rem .65rem;border-radius:6px;background:rgba(255,255,255,.35);backdrop-filter:blur(4px);-webkit-backdrop-filter:blur(4px);box-shadow:0 1px 2px rgba(0,0,0,.08);transition:background var(--transition),transform var(--transition);}nav li a:hover{background:rgba(255,255,255,.55);}nav li a.active{background:var(--yellow-accent);color:#1e293b;}
.menu-heading{margin-top:.4rem;font-size:.7rem;letter-spacing:.12em;text-transform:uppercase;font-weight:700;opacity:.75;padding:.4rem .5rem .2rem;}
.submenu-inline{display:flex;flex-direction:column;margin-left:.25rem;padding-left:.25rem;border-left:2px solid rgba(255,255,255,.4);gap:.1rem;}
.submenu-inline a{background:transparent;box-shadow:none;font-size:.8rem;padding:.4rem .55rem;color:#1e293b;opacity:.85;}
.submenu-inline a.active{background:var(--yellow-accent);opacity:1;}
/* Collapsible Learn disclosure */
.nav-disclosure{display:flex;flex-direction:column;}
.nav-disclosure summary{list-style:none;cursor:pointer;display:flex;align-items:center;justify-content:space-between;font-weight:600;padding:.55rem .65rem;border-radius:6px;background:rgba(255,255,255,.25);transition:background var(--transition);} 
.nav-disclosure summary::-webkit-details-marker{display:none;}
.nav-disclosure summary:hover{background:rgba(255,255,255,.45);} 
.nav-disclosure[open] summary{background:var(--yellow-accent);color:#1e293b;}
.nav-disclosure summary .chevron{transition:transform var(--transition);font-size:.8rem;opacity:.8;}
.nav-disclosure[open] summary .chevron{transform:rotate(180deg);}
.nav-disclosure .submenu-collapsible{display:flex;flex-direction:column;margin-top:.25rem;margin-left:.25rem;padding-left:.5rem;border-left:2px solid rgba(0,0,0,.15);gap:.15rem;animation:fadeSlide .25s ease;}
.nav-disclosure .submenu-collapsible a{background:transparent;font-size:.8rem;padding:.35rem .4rem;box-shadow:none;}
.nav-disclosure .submenu-collapsible a.active{background:var(--yellow-accent);color:#1e293b;}
@keyframes fadeSlide{from{opacity:0;transform:translateY(-4px);}to{opacity:1;transform:translateY(0);}}
main{flex:1;display:flex;flex-direction:column;}
.topbar{display:flex;align-items:center;justify-content:space-between;padding:1rem 1.5rem;background:var(--bg-alt);border-bottom:1px solid rgba(0,0,0,.08);backdrop-filter:blur(4px);position:sticky;top:0;z-index:10;}
.search{position:relative;display:flex;align-items:center;}
.search input{padding:.55rem .75rem .55rem 2.1rem;border:1px solid rgba(0,0,0,.15);border-radius:8px;font-size:.9rem;background:#fff;box-shadow:0 1px 2px rgba(0,0,0,.04);}body.dark .search input{background:#1e293b;border-color:#334155;color:#f1f5f9;}
.search svg{position:absolute;left:.6rem;width:18px;height:18px;stroke:#0f172a;stroke-width:2;opacity:.7;}
.content{padding:2rem clamp(1rem,4vw,3rem);max-width:1100px;}
.grid{display:grid;gap:2rem;grid-template-columns:repeat(auto-fit,minmax(250px,1fr));}
/* Legacy card & badge styles removed (Tailwind tw-card used instead) */
footer{margin-top:auto;padding:2rem 1.5rem;font-size:.8rem;opacity:.8;text-align:center;}
.btn{display:inline-flex;align-items:center;gap:.4rem;font-weight:600;border-radius:8px;padding:.65rem 1rem;background:var(--blue-accent);color:#fff;letter-spacing:.02em;text-shadow:0 1px 1px rgba(0,0,0,.35);box-shadow:0 2px 6px -2px rgba(0,0,0,.3);transition:background var(--transition),transform var(--transition);} .btn:hover,.btn:focus{background:#1d4ed8;color:#fff;outline:none;} .btn:focus-visible{box-shadow:0 0 0 3px #fff,0 0 0 5px var(--blue-accent);} .btn:active{transform:translateY(1px);} 
/* Removed obsolete theme toggle styles */
@media (max-width:960px){.layout{flex-direction:column;}.sidebar{position:relative;width:100%;flex-direction:row;overflow:auto;max-height:none;}nav ul{flex-direction:row;flex-wrap:wrap;}.submenu{position:relative;border-left:none;margin-left:0;padding-left:0;}}
.skip-link{position:absolute;left:-999px;top:auto;width:1px;height:1px;overflow:hidden;} .skip-link:focus{left:1rem;top:1rem;width:auto;height:auto;background:#000;color:#fff;padding:.5rem 1rem;z-index:1000;border-radius:6px;}