.concepts-section{z-index:1;padding:0 0 60px;position:relative}.concepts-content{max-width:none;margin:0 auto}.deck-tabs{border-radius:var(--radius-pill);background:var(--surface);border:1px solid var(--border);scrollbar-width:none;gap:4px;margin-bottom:16px;padding:4px;display:flex;overflow-x:auto}.deck-tabs::-webkit-scrollbar{display:none}.deck-tab{appearance:none;cursor:pointer;border-radius:var(--radius-pill);min-height:44px;font-family:var(--font-mono);font-size:var(--text-14);color:var(--text-muted);white-space:nowrap;background:0 0;border:0;flex:1 0 auto;justify-content:center;align-items:center;gap:8px;padding:10px 18px;font-weight:500;transition:color .2s,background-color .2s;display:inline-flex}.deck-tab:hover{color:var(--ink)}.deck-tab.is-active{color:var(--bg);background:var(--ink);font-weight:700}.deck-tab-num{font-size:var(--text-12)}.deck-tab.is-active .deck-tab-num{opacity:.6}.deck-tab:focus-visible,.deck-rail-item:focus-visible,.deck-nav-btn:focus-visible{outline:2px solid var(--ink);outline-offset:2px}.deck-chapter.card,.deck-chapter.card:hover{margin-bottom:var(--space-4);transform:none}.deck-chapter[hidden]{display:none}.deck-lead{max-width:860px;margin-bottom:28px}.deck-lead h2{font-size:var(--text-32);color:var(--accent);margin-bottom:16px;font-weight:700}.deck-lead p{font-size:var(--text-17);color:var(--ink);margin-bottom:12px;line-height:1.7}.deck-lead p:last-child{margin-bottom:0}.deck-body{grid-template-columns:280px minmax(0,1fr);align-items:start;gap:24px;display:grid}.deck-rail{flex-direction:column;gap:4px;display:flex}.deck-rail-item{appearance:none;cursor:pointer;border-radius:var(--radius-card-sm);text-align:left;width:100%;min-height:44px;color:var(--text-muted);background:0 0;border:1px solid #0000;align-items:baseline;gap:12px;padding:10px 14px;transition:color .2s,background-color .2s,border-color .2s;display:flex}.deck-rail-item:hover{color:var(--ink);background:var(--surface-hover)}.deck-rail-item.is-active{color:var(--ink);background:var(--bg-3);border-color:var(--border-strong)}.deck-rail-num{font-family:var(--font-mono);font-size:var(--text-12);flex-shrink:0}.deck-rail-title{font-size:var(--text-15);font-weight:600;line-height:1.35}.deck-slides{display:grid}.deck-slide{background:var(--bg-3);border:1px solid var(--border);border-radius:var(--radius-card-md);opacity:0;visibility:hidden;grid-area:1/1;padding:32px;transition:opacity .25s,transform .25s,visibility 0s linear .25s;transform:translateY(6px)}.deck-slide.is-active{opacity:1;visibility:visible;transition:opacity .25s,transform .25s,visibility;transform:none}.deck-slide-header{align-items:center;gap:14px;margin-bottom:20px;display:flex}.deck-slide-header h3{font-size:var(--text-24);color:var(--accent);flex:1;margin:0;font-weight:700}.deck-slide-count{font-family:var(--font-mono);font-size:var(--text-12);color:var(--text-muted);align-self:flex-start}.deck-slide-body{font-size:var(--text-18);color:var(--ink);max-width:68ch;margin-bottom:16px;line-height:1.7}.deck-slide-body strong{font-weight:600}.deck-example{background:var(--surface);border:1px solid var(--border-strong);border-radius:var(--radius-card-sm);margin:0 0 14px;padding:16px 20px}.deck-example h4{font-size:var(--text-16);color:var(--accent);margin-bottom:8px;font-weight:600}.deck-example p{font-size:var(--text-15);color:var(--ink);margin:0;line-height:1.6}.deck-nav{justify-content:space-between;align-items:center;gap:12px;margin-top:16px;display:flex}.deck-nav-btn{appearance:none;cursor:pointer;border-radius:var(--radius-pill);border:1px solid var(--border-strong);background:var(--surface);max-width:42%;min-height:44px;color:var(--ink);font-size:var(--text-14);align-items:center;gap:10px;padding:10px 16px;font-weight:600;transition:background-color .2s,border-color .2s;display:inline-flex}.deck-nav-btn:hover:not(:disabled){background:var(--surface-hover);border-color:var(--border-soft)}.deck-nav-btn:disabled{opacity:.4;cursor:default}.deck-nav-next{background:var(--ink);border-color:var(--ink);color:var(--bg)}.deck-nav-next:hover:not(:disabled){background:var(--ink-hover);border-color:var(--ink-hover)}.deck-nav-label{text-overflow:ellipsis;white-space:nowrap;overflow:hidden}.deck-dots{gap:6px;display:flex}.deck-dot{background:var(--border-soft);border-radius:50%;width:6px;height:6px;transition:width .2s,background-color .2s}.deck-dot.is-active{background:var(--ink);border-radius:3px;width:18px}.type-icon-wrapper{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-card-sm);flex-shrink:0;justify-content:center;align-items:center;width:44px;height:44px;display:flex}.type-icon{font-size:var(--text-20);color:var(--accent)}.section-icon{font-size:var(--text-28);color:var(--accent);vertical-align:-.1em;margin-right:12px}.journey-number{background:var(--accent);width:44px;height:44px;color:var(--bg);font-size:var(--text-20);border-radius:50%;flex-shrink:0;justify-content:center;align-items:center;font-weight:800;display:flex}.type-note{font-size:var(--text-15);color:var(--text-muted);border-top:1px solid var(--border);margin:20px 0 0;padding-top:16px;font-style:italic;line-height:1.6}.deck-more{margin-top:var(--space-4)}.deck-more h2{font-size:var(--text-20);color:var(--accent);margin-bottom:14px;font-weight:700}.deck-more-grid{grid-template-columns:repeat(3,minmax(0,1fr));gap:10px;display:grid}.deck-more-link{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-14);color:var(--ink);flex-direction:column;gap:4px;padding:16px 44px 16px 18px;text-decoration:none;transition:border-color .2s,background-color .2s;display:flex;position:relative}.deck-more-link:hover{border-color:var(--border-soft);background:var(--surface-soft)}.deck-more-link:focus-visible{outline:2px solid var(--ink);outline-offset:2px}.deck-more-title{font-size:var(--text-16);font-weight:600}.deck-more-desc{font-size:var(--text-14);color:var(--text-muted);line-height:1.45}.deck-more-arrow{font-size:var(--text-14);color:var(--text-faint);transition:translate .2s,color .2s;position:absolute;top:50%;right:18px;translate:0 -50%}.deck-more-link:hover .deck-more-arrow{color:var(--ink);translate:3px -50%}@media (prefers-reduced-motion:reduce){.deck-slide,.deck-slide.is-active{transition:none;transform:none}}@media (max-width:860px){.concepts-section{padding:0 0 40px}.deck-tabs{border-radius:var(--radius-14)}.deck-tab{flex:none;padding:10px 14px}.deck-lead h2{font-size:var(--text-26)}.deck-body{grid-template-columns:minmax(0,1fr);gap:14px}.deck-rail{scroll-snap-type:x mandatory;scrollbar-width:none;flex-direction:row;margin:0 -4px;padding:0 4px 2px;overflow-x:auto}.deck-rail::-webkit-scrollbar{display:none}.deck-rail-item{scroll-snap-align:start;border-color:var(--border);border-radius:var(--radius-pill);flex:none;align-items:center;width:auto;padding:8px 14px}.deck-rail-title{font-size:var(--text-14);white-space:nowrap}.deck-slide{padding:22px}.deck-slide:not(.is-active){display:none}.deck-slide-header h3{font-size:var(--text-20)}.deck-slide-body{font-size:var(--text-16)}.deck-nav-label{display:none}.deck-nav-btn{padding:10px 14px}.deck-more-grid{grid-template-columns:minmax(0,1fr)}}@media (min-width:861px) and (max-width:1080px){.deck-more-grid{grid-template-columns:repeat(2,minmax(0,1fr))}}