.concepts-page{background:var(--warm-white);min-height:100vh;color:var(--primary-dark)}.concepts-hero{text-align:center;--hero-media-image:url(/assets/images/concepts-hero.jpg);--hero-media-position:center 75%;min-height:clamp(280px,48vh,420px);padding:clamp(3rem,5vw,4rem) 2rem 3rem}.concepts-hero:before{background:linear-gradient(135deg,#0c0c0c99,#14141480)}.concepts-hero:after{opacity:.08}.concepts-hero .page-hero-content{max-width:960px;padding:0 2rem}.concepts-page-code{color:var(--accent-light);letter-spacing:2px;text-transform:uppercase;margin-bottom:1rem;font-family:JetBrains Mono,monospace;font-size:.85rem}.concepts-hero h1{letter-spacing:1.5px;text-transform:uppercase;margin-bottom:.75rem;font-size:clamp(2rem,6vw,4rem);font-weight:800}.concepts-hero p{opacity:.85;max-width:640px;margin:0 auto;font-family:JetBrains Mono,monospace;font-size:1rem}.concepts-content{max-width:1100px;margin:0 auto;padding:2rem 1.5rem 5rem}.concepts-filter{margin-bottom:2rem;display:block}.concepts-filter summary{text-transform:uppercase;letter-spacing:.35rem;cursor:pointer;justify-content:space-between;align-items:center;gap:.5rem;margin-bottom:.75rem;padding:0;font-family:JetBrains Mono,monospace;font-size:.8rem;list-style:none;display:flex}.concepts-filter summary::-webkit-details-marker{display:none}.concepts-filter summary::marker{content:""}@media (max-width:768px){.concepts-filter summary:after{content:"▾";letter-spacing:normal;font-size:.9rem}}.concepts-filter[open] summary{margin-bottom:1rem}.concepts-filter-body{grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:.75rem;display:grid}.concepts-filter button,.concepts-filter-body button{letter-spacing:.5px;text-transform:uppercase;cursor:pointer;background:#f8f9fa;border:1px solid #dcdcdc;border-radius:6px;justify-content:space-between;align-items:center;gap:.35rem;width:100%;padding:.4rem .8rem;font-family:JetBrains Mono,monospace;font-size:.8rem;transition:background .2s,border-color .2s,color .2s;display:inline-flex}.concepts-filter button.active{background:var(--light-grey);border-color:var(--accent-light);color:var(--primary-dark)}.concepts-grid{grid-template-columns:repeat(auto-fit,minmax(320px,1fr));gap:2rem;display:grid}.concept-card{border-top:1px solid #0003;flex-direction:column;gap:.9rem;padding-top:1.4rem;display:flex}.concept-card header{text-transform:uppercase;letter-spacing:.2rem;flex-wrap:wrap;justify-content:space-between;align-items:flex-start;gap:.4rem;display:flex}.concept-code{color:var(--accent-grey);font-family:JetBrains Mono,monospace;font-size:.8rem}.concept-card header h3{margin:0;font-family:Capture It,sans-serif;font-size:1.4rem}.concept-meta{color:var(--accent-grey);flex-direction:column;align-items:flex-end;gap:.25rem;font-family:JetBrains Mono,monospace;font-size:.75rem;display:flex}.concept-meta a{color:inherit;letter-spacing:.1rem;text-decoration:underline}.concept-body{flex-direction:column;gap:.8rem;line-height:1.7;display:flex}.concept-body .btn{align-self:flex-start}@media (max-width:768px){.concepts-content{padding:3rem 1rem}.concepts-filter summary{margin-bottom:.5rem}.concepts-filter:not([open]) .concepts-filter-body{display:none}}