/* ── Chapter Showcase ────────────────────────────────────────── */
.acs-wrap{box-sizing:border-box;display:grid;grid-template-columns:5fr 7fr;gap:48px;align-items:stretch}
.acs-wrap *{box-sizing:border-box}

/* Chapter list */
.acs-nav{position:relative;display:flex;flex-direction:column;border-left:3px solid var(--acs-rail,#D7E4EC)}
.acs-indicator{position:absolute;left:-3px;width:3px;background:linear-gradient(180deg,var(--acs-ind1,#E8A91E),var(--acs-ind2,#FFC43D));border-radius:3px;transition:top .45s cubic-bezier(.65,.05,.36,1),height .45s cubic-bezier(.65,.05,.36,1);box-shadow:0 0 10px rgba(255,196,61,.55)}
.acs-item{-webkit-appearance:none;appearance:none;font:inherit;white-space:normal;text-transform:none;box-shadow:none;width:100%;display:flex;align-items:center;gap:18px;background:none;border:0;cursor:pointer;padding:20px 18px 20px 26px;text-align:left;border-radius:0 12px 12px 0;transition:background .25s ease;-webkit-tap-highlight-color:transparent}
.acs-item:hover{background:var(--acs-item-hbg,#F4FAFC)}
.acs-item.is-active{background:var(--acs-item-abg,#EDFAFD)}
.acs-numwrap{position:relative;flex:none;width:44px;height:44px;display:flex;align-items:center;justify-content:center;border-radius:50%}
.acs-item.is-active .acs-numwrap{background:var(--acs-med,#FFC43D);box-shadow:0 6px 18px rgba(255,196,61,.45)}
.acs-ringsvg{position:absolute;inset:0;transform:rotate(-90deg)}
.acs-ring-bg{fill:none;stroke:var(--acs-rail,#D7E4EC);stroke-width:2.5}
.acs-item.is-active .acs-ring-bg{stroke:rgba(255,255,255,.5)}
.acs-ring-fg{fill:none;stroke:var(--acs-ring,#E8A91E);stroke-width:2.5;stroke-linecap:round;stroke-dasharray:100;stroke-dashoffset:100}
.acs-ring-fg.is-run{animation:acsRing var(--acs-ring-dur,5200ms) linear forwards}
@keyframes acsRing{from{stroke-dashoffset:100}to{stroke-dashoffset:0}}
.acs-num{font-family:'Playfair Display',Georgia,serif;font-weight:800;font-size:1rem;color:var(--acs-num,#9AA8B4);transition:color .25s;position:relative;z-index:1}
.acs-item.is-done .acs-num{color:var(--acs-num-done,#E8A91E)}
.acs-item.is-active .acs-num{color:var(--acs-num-act,#2B3D54)}
.acs-name{font-family:'Playfair Display',Georgia,serif;font-weight:700;font-size:1.14rem;line-height:1.3;color:var(--acs-name,#7D8D9B);transition:color .25s}
.acs-item.is-done .acs-name{color:var(--acs-name-done,#3A506B)}
.acs-item.is-active .acs-name{color:var(--acs-name-act,#2B3D54)}
.acs-item:focus-visible{outline:3px solid #E8A91E;outline-offset:-3px}

/* Stage */
.acs-stage{position:relative;border:1px solid #D7E4EC;border-radius:18px;background:#F4FAFC;padding:44px 46px;overflow:hidden;box-shadow:0 16px 44px rgba(58,80,107,.09);display:flex;align-items:center}
.acs-panel{display:none;width:100%}
.acs-panel.is-active{display:block}
.acs-ghost{position:absolute;right:14px;bottom:-34px;font-family:'Playfair Display',Georgia,serif;font-weight:800;font-size:11rem;line-height:1;color:rgba(58,80,107,.06);pointer-events:none;user-select:none}
.acs-content{position:relative;z-index:1;max-width:560px}
.acs-content.is-in{animation:acsIn .45s cubic-bezier(.4,.1,.2,1)}
@keyframes acsIn{from{opacity:0;transform:translateY(14px)}to{opacity:1;transform:none}}
@media(prefers-reduced-motion:reduce){.acs-content.is-in{animation:none}.acs-ring-fg.is-run{animation:none}}
.acs-eyebrow{font-weight:700;font-size:.72rem;letter-spacing:.1em;text-transform:uppercase;color:#E8A91E;display:block;margin-bottom:10px}
.acs-panel h3{font-family:'Playfair Display',Georgia,serif;font-size:1.6rem;line-height:1.25;margin:0 0 .45em;color:#2B3D54}
.acs-panel h3:after{content:"";display:block;width:46px;height:3px;background:#FFC43D;border-radius:3px;margin-top:.5rem}
.acs-panel p{font-size:1.07rem;line-height:1.65;margin:0;color:#33485E}

/* Responsive */
@media(max-width:900px){
  .acs-wrap{grid-template-columns:1fr;gap:22px}
  .acs-stage{padding:30px 24px}
  .acs-ghost{font-size:7rem;bottom:-24px}
  .acs-item{padding:14px 12px 14px 20px}
  .acs-name{font-size:1.02rem}
  .acs-panel h3{font-size:1.3rem}
  .acs-panel p{font-size:1rem}
}