*{box-sizing:border-box} :root{
--color-black:#000000;--color-tan:#86745c;--color-light-tan:#c2baab;--color-dark-tan:#6a5c48;
--color-white:#ffffff;--color-black-63:rgba(0,0,0,.63);--color-black-80:rgba(0,0,0,.8);--color-black-88:rgba(0,0,0,.88);
--color-gold:#b19977;--color-accent:#b19977;--color-accent-light:#c2baab;
--bg:#f4f1eb;--panel:#fff;--text:#171513;--muted:#6b655d;--border:#ddd5c8;--shadow:0 10px 28px rgba(0,0,0,.09)
}
*{scrollbar-color:var(--color-tan) transparent}body{margin:0;background:var(--bg);color:var(--text);font-family:Inter,Segoe UI,Arial,sans-serif;line-height:1.5}
.topbar{height:72px;background:var(--color-black);color:#fff;display:flex;align-items:center;justify-content:space-between;padding:0 24px;position:sticky;top:0;z-index:10}
.brand{display:flex;align-items:center;gap:12px}.brand-mark{background:var(--color-tan);padding:8px 10px;border-radius:8px;font-weight:900}.brand strong{display:block}.brand small{color:#cfcac2}
.icon-btn{border:1px solid #555;background:#1c1c1c;color:#fff;border-radius:8px;padding:8px 12px;cursor:pointer}
.layout{display:flex;min-height:calc(100vh - 112px)}.sidebar{width:245px;background:#0d0d0d;color:#fff;padding:20px 14px;flex-shrink:0}
.nav-btn{width:100%;text-align:left;border:0;background:transparent;color:#ddd;padding:12px 14px;border-radius:8px;margin-bottom:5px;cursor:pointer;font-weight:700}
.nav-btn:hover,.nav-btn.active{background:var(--color-tan);color:#fff}.side-card{margin-top:28px;padding:14px;border:1px solid #333;border-radius:10px;color:#ccc;font-size:.9rem}.side-card strong{color:#fff}
main{max-width:1200px;width:100%;padding:30px;margin:auto}.hero{background:linear-gradient(135deg,var(--color-dark-tan),var(--color-tan));color:#fff;border-radius:16px;padding:30px;box-shadow:var(--shadow)}
.hero h1{margin:0 0 8px;font-size:clamp(1.8rem,4vw,2.8rem)}.hero p{max-width:760px;color:#f2eee8}
.grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px;margin-top:20px}.card{background:var(--panel);border:1px solid var(--border);border-radius:14px;padding:20px;box-shadow:var(--shadow)}
.card h3{margin-top:0}.metric{font-size:2rem;font-weight:900;color:var(--color-dark-tan)}.btn{border:0;border-radius:9px;padding:11px 16px;background:var(--color-tan);color:#fff;font-weight:800;cursor:pointer}.btn.secondary{background:#ece7df;color:#29251f}.btn:disabled{opacity:.5;cursor:not-allowed}
.toolbar{display:flex;gap:10px;flex-wrap:wrap;margin:18px 0}.select,.search{padding:10px;border:1px solid var(--border);border-radius:8px;background:#fff}
.notes-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:18px}.note li{margin:8px 0}.section-title{margin-top:32px;border-bottom:3px solid var(--color-light-tan);padding-bottom:8px}
.quiz-wrap{max-width:850px;margin:auto}.progress{height:10px;background:#e3ddd3;border-radius:99px;overflow:hidden}.progress>div{height:100%;background:var(--color-tan);transition:width .2s}
.q-card{margin-top:18px}.question{font-size:1.25rem;font-weight:800}.option{display:block;border:1px solid var(--border);padding:13px;margin:10px 0;border-radius:10px;cursor:pointer;background:#fff}.option:hover{border-color:var(--color-tan)}.option input{margin-right:10px}
.quiz-footer{display:flex;justify-content:space-between;gap:10px;margin-top:20px}.feedback{margin-top:15px;padding:14px;border-radius:10px;background:#eee8df}.correct{border-left:5px solid #587b5a}.incorrect{border-left:5px solid #9b4e45}
.result-big{text-align:center;padding:28px}.score{font-size:3.2rem;font-weight:900;color:var(--color-dark-tan)}
.review{margin-top:20px}.review-item{padding:15px;border:1px solid var(--border);border-radius:10px;background:#fff;margin:10px 0}
footer{text-align:center;padding:20px;background:#000;color:#bbb;font-size:.85rem}
.dark{--bg:#12110f;--panel:#1d1b18;--text:#f1ede6;--muted:#bdb5aa;--border:#403a32}.dark .card,.dark .option,.dark .review-item,.dark .search,.dark .select{background:#1d1b18;color:var(--text)}.dark .btn.secondary{background:#39342d;color:#fff}.dark .progress{background:#38332c}
@media(max-width:850px){.sidebar{width:190px}.grid{grid-template-columns:1fr 1fr}.notes-grid{grid-template-columns:1fr}}
@media(max-width:650px){.topbar{padding:0 12px}.layout{display:block}.sidebar{width:100%;padding:8px;position:sticky;top:72px;z-index:9}.sidebar nav{display:flex;overflow:auto;gap:5px}.nav-btn{white-space:nowrap;width:auto;margin:0}.side-card{display:none}main{padding:18px}.grid{grid-template-columns:1fr}.notes-grid{grid-template-columns:1fr}.hero{padding:22px}}