:root{--bg-primary:#0a0a0c;--bg-secondary:#121215;--bg-tertiary:#1a1a20;--text-primary:#e6e6e6;--text-secondary:#a0a0ab;--text-muted:#666670;--accent-primary:#4f46e5;--accent-success:#10b981;--accent-error:#ef4444;--border-subtle:#ffffff14;--border-strong:#ffffff26;--shadow-sm:0 1px 2px #00000080;--shadow-md:0 4px 6px #00000080;--radius-sm:.25rem;--radius-md:.5rem;--radius-lg:1rem;--transition-fast:.15s ease-in-out;--transition-smooth:.3s cubic-bezier(.4, 0, .2, 1)}*{box-sizing:border-box;margin:0;padding:0}body{background-color:var(--bg-primary);color:var(--text-primary);-webkit-font-smoothing:antialiased;min-height:100vh;font-family:Inter,system-ui,-apple-system,sans-serif;line-height:1.6}h1,h2,h3,h4,h5,h6{color:var(--text-primary);margin-bottom:1rem;font-weight:500;line-height:1.2}p{color:var(--text-secondary);margin-bottom:1.5rem}a{color:var(--text-primary);transition:color var(--transition-fast);text-decoration:none}a:hover{color:var(--accent-primary)}.container{width:100%;max-width:1200px;margin:0 auto;padding:0 1.5rem}.flex-center{justify-content:center;align-items:center;display:flex}.grid-2{grid-template-columns:1fr;gap:2rem;display:grid}@media (width>=768px){.grid-2{grid-template-columns:1fr 1fr}}.btn{border-radius:var(--radius-md);cursor:pointer;transition:all var(--transition-fast);background:var(--bg-tertiary);color:var(--text-primary);border:1px solid #0000;justify-content:center;align-items:center;padding:.75rem 1.5rem;font-weight:500;display:inline-flex}.btn:hover{background:var(--border-strong)}.btn-primary{background:var(--text-primary);color:var(--bg-primary)}.btn-primary:hover{background:var(--text-secondary)}.btn-sos{color:var(--text-muted);border:1px solid var(--border-subtle);background:0 0}.btn-sos:hover{color:var(--accent-error);border-color:var(--accent-error);background:#ef44441a}.flip-card-container{perspective:1000px;margin-bottom:1.5rem}.flip-card-inner{width:100%;height:100%;min-height:150px;transform-style:preserve-3d;cursor:pointer;transition:transform .6s;position:relative}.flip-card-inner.flipped{transform:rotateY(180deg)}.flip-card-front,.flip-card-back{backface-visibility:hidden;border-radius:var(--radius-md);background-color:var(--bg-secondary);border:1px solid var(--border-subtle);flex-direction:column;justify-content:center;width:100%;height:100%;padding:1.5rem;display:flex;position:absolute}.flip-card-back{background-color:var(--bg-tertiary);transform:rotateY(180deg)}.glossary-word{-webkit-text-decoration:underline dashed var(--border-strong);text-decoration:underline dashed var(--border-strong);cursor:help;display:inline-block;position:relative}