.ec-shell{width:min(1100px,100%);margin:auto;padding:clamp(12px,3vw,32px)}
.ec-paper{margin-top:16px;background:var(--tl-glass);border:1px solid var(--tl-glass-border);border-radius:var(--tl-radius-surface);box-shadow:var(--tl-shadow);backdrop-filter:blur(var(--tl-blur))}
.ec-hero{padding:clamp(28px,5vw,60px);border-bottom:1px solid var(--tl-hair)}
.ec-kicker{color:var(--tl-sepia);letter-spacing:.13em;font:500 17px/1.7 var(--tl-font-jp);margin:0}
.ec-hero h1{font:750 clamp(30px,4.5vw,48px)/1.2 var(--tl-font-ui);margin:12px 0 16px}
.ec-hero p:not(.ec-kicker){font-size:18px;line-height:1.7;color:var(--tl-ink-soft);margin:0}
.ec-continue{display:inline-flex;align-items:center;min-height:48px;margin-top:22px;padding:10px 18px;background:var(--tl-seal);color:var(--tl-paper);border-radius:var(--tl-radius-control);font-weight:650;text-decoration:none}
.ec-continue[hidden]{display:none}
.ec-contents{padding:clamp(20px,4vw,44px)}
.ec-contents h2{font:650 20px/1.5 var(--tl-font-ui);margin:0 0 18px}
.ec-chapter,.ec-topic{border:0;border-top:1px solid var(--tl-hair);border-radius:0;box-shadow:none;background:transparent}
.ec-chapter:last-child{border-bottom:1px solid var(--tl-hair)}
.ec-chapter>summary,.ec-topic>summary{position:relative;list-style:none;cursor:pointer;min-height:64px;padding:18px 34px 18px 0;color:var(--tl-ink);font:600 19px/1.5 var(--tl-font-ui)}
.ec-chapter>summary{display:flex;gap:18px;align-items:center}
.ec-chapter-number{font:500 28px/1 var(--tl-font-jp);color:var(--tl-sepia);min-width:36px}
.ec-chapter>summary small,.ec-topic>summary small{display:block;color:var(--tl-ink-soft);font-size:14px;font-weight:400;margin-top:4px}
.ec-toggle{position:absolute;right:2px;top:20px;font:400 24px/1 var(--tl-font-ui);color:var(--tl-seal)}
.ec-chapter[open]>summary>.ec-toggle,.ec-topic[open]>summary>.ec-toggle{font-size:0}.ec-chapter[open]>summary>.ec-toggle::before,.ec-topic[open]>summary>.ec-toggle::before{content:'−';font-size:24px}
.ec-chapter>summary::-webkit-details-marker,.ec-topic>summary::-webkit-details-marker{display:none}
.ec-topics{padding:0 0 20px 54px}
.ec-topic>summary{font-size:17px;min-height:58px}
.ec-lessons{list-style:none;margin:0;padding:0}
.ec-lessons li{margin:0;border-top:1px solid var(--tl-hair)}
.ec-lesson{display:flex;gap:14px;align-items:center;justify-content:space-between;min-height:58px;padding:14px 4px;text-decoration:none;color:var(--tl-ink);font-size:16px;line-height:1.65}
.ec-lesson:hover{color:var(--tl-seal)}
.ec-lesson>[aria-hidden]{flex:none;color:var(--tl-sepia)}
.ec-lesson:focus-visible,summary:focus-visible,.ec-continue:focus-visible{outline:2px solid var(--tl-seal);outline-offset:4px;border-radius:4px}
.ec-foot{padding:20px clamp(20px,4vw,44px);border-top:1px solid var(--tl-hair);color:var(--tl-ink-soft);font-size:16px}
.ec-foot a{display:inline-flex;align-items:center;min-height:44px;color:inherit;line-height:1.6}
@media(max-width:600px){.ec-topics{padding-left:0}.ec-chapter>summary{font-size:18px;gap:12px}.ec-chapter-number{min-width:30px;font-size:25px}.ec-hero{padding:28px 20px}.ec-contents{padding:20px}}